Non-Occlusive Small Bowel Necrosis in Association with Feeding Jejunostomy After Elective Upper Gastrointestinal Surgery

INTRODUCTION

Non-occlusive small bowel necrosis (NOSBN) has been associated with early postoperative enteral feeding. The purpose of this study was to determine the incidence of this complication in an elective upper gastrointestinal (GI) surgical patient population and the influence of both patient selection and type of feeding jejunostomy (FJ) inserted, based on the experience of two surgical units in affiliated hospitals.

PATIENTS AND METHODS

The records were reviewed of 524 consecutive patients who underwent elective upper GI operations with insertion of a FJ for benign or malignant disease between 1997 and 2006. One unit routinely inserted needle catheter jejunostomies (NCJ), whilst the other selectively inserted tube jejunostomies (TJ).

RESULTS

Six cases of NOSBN were identified over 120 months in 524 patients (1.15%), with no difference in incidence between routine NCJ (n = 5; 1.16%) and selective TJ (n = 1; 1.06%). Median rate of feeding at time of diagnosis was 105 ml/h (range, 75–125 ml/h), and diagnosis was made at a median of 6 days (range, 4–18 days) postoperatively. All patients developed abdominal distension, hypotension and tachycardia in the 24 h before re-exploratory laparotomy. Five patients died and one patient survived.

CONCLUSIONS

The understanding of the pathophysiology of NOSBN is still rudimentary; nevertheless, its 1% incidence in the present study does call into question its routine postoperative use especially in those at high risk with an open abdomen, planned repeat laparotomies or marked bowel oedema. Patients should be fully resuscitated before initiating any enteral feeding, and feeding should be interrupted if there is any evidence of feed intolerance.     

Cardiovascular effects of apnoea in preterm infants

Cardiovascular reflex responses have been studied in 9 newborn preterm infants with apnoeic episodes and in 2 preterm infants with periodic breathing. Respiration, blood pressure, heart rate, and peripheral blood flow were simultaneously recorded. Peripheral blood flow was measured in the leg by venous occlusion plethysmography. During apnoea, bradycardia and peripheral vasoconstriction occur. There is little change in blood pressure though pulse pressure increases. No cardiovascular changes were seen before the onset of apnoea. Periodic breathing had little effect on peripheral blood flow. Preterm infants with gestations as low as 27 weeks apparently have well developed chemoreceptor reflexes which would tend to preserve blood supply to the brain during conditions of hypoxia.     

Effects of S-carboxymethyl-l-cysteine on pulmonary sialyl transferase activity in vitro, in healthy and in sulphur-dioxide-induced bronchitic rats

S-carboxymethyl-L-cysteine (carbocysteine) improves the visco-elastic properties of bronchial mucus in vivo, possibly as a result of an increase in the relative proportions of sialomucins in bronchial mucus. Carbocysteine was therefore studied in vitro and ex vivo in both normal and bronchitic rats on pulmonary sialyl transferase, responsible for the addition of sialic acid to mucus glycoproteins. Bronchitis was induced in male Sprague-Dawley rats by repeated exposure to sulphur dioxide for two weeks. During this time they received either 500 mg kg-1 day-1 carbocysteine or its vehicle by the oral route. Rats not being exposed to SO2 received the same treatment. The animals were then killed, and subcellular fractions prepared by differential centrifugation of lung homogenates. Sialyl transferase was assayed using CMP-14C sialic acid as substrate and desialysed fetuin as exogenous acceptor. Enzyme activity was located in both the (Golgi-containing) 10,000 g and 100,000 g pellets with minor activity in the cytosolic supernatants. When tested in vitro between 10(-6) and 10(-3) M, carbocysteine had no effect on sialyl transferase activity in microsomes taken from healthy or bronchitis rats. Repeated administration of carbocysteine was without effect on the sialyl transferase activity in 10,000 g pellets taken from healthy rats. However, in bronchitic rats there was a small but statistically significant (P less than 0.05) increase in enzymic activity in the treated group compared to the animals receiving the vehicle. There was no difference in the activity of the microsomal enzyme compared to vehicle-treated controls in either healthy or bronchitic rats. We conclude that it is possible that an increase in sialyl transferase activity in a Golgi-containing fraction of bronchitic lungs could explain the relative increase in sialomucins in bronchitic subjects.     

4-O-卤代酰基-4′-去甲基表鬼臼毒素类似物的合成与抗肿瘤活性

为考察4′-去甲表鬼臼毒素C₄位上联结含卤素原子的酯化侧链时对化合物抗肿瘤活性的影响,设计并采用选择性酯化方法合成了9个新的4′-去甲基表鬼臼毒素酯化产物。其中标题化合物在L₁₂₁₀白血病肿瘤细胞与KB细胞的体外生长抑制试验中普遍表现出显著的抑制活性,大部分化合物活性超过依托泊甙。而普通脂酸酯的活性较弱。     

4-酰胺基-4-脱氧-4′-去甲表鬼臼毒素衍生物的合成和抗肿瘤活性

4′-去甲表鬼臼毒素与叠氮酸在三氟化硼乙醚存在下缩合,并经还原得4-氨基-4-脱氧-4′-去甲表鬼臼毒素。该中间体与酸或酸酐反应得相应酰胺化合物24个。经体外筛选,多数化合物抑制L₁₂₁₀和KB细胞活性相当或超过依托泊甙。与相应的醚、酯、胺等类型相比,这一类化合物活性最强。     

Autostimulation of growth by human myelogenous leukemia cells (HL-60)

We have studied the effects of medium conditioned by the human progranulocytic leukemia cell line, HL-60, on the subsequent growth of new inocula of HL-60 cells. When HL-60 cells were cultured at high cell density, optimal growth rate occurred in liquid suspension and confluent colony growth was observed in viscous medium without the addition of conditioned medium. However, when cells were cultured at lower cell density, growth rate was reduced and colony growth was nil unless conditioned medium from HL-60 culture was added. All HL-60 populations studied, including the earliest available passage, 9, both elaborated and responded to HL-60 CM. HL-60 CM did not stimulate normal human or mouse granulocyte-monocyte colony-forming cell (CFU-GM) growth. Conditioned media from other human cell lines varied in the ability to stimulate HL-60 cell and CFU-GM proliferation. Some, such as GCT CM, stimulated both HL-60 cells and normal CFU-GM, whereas others, like HL-60 CM, stimulated only HL-60 growth. The majority of cell line CMs tested did not stimulate either HL-60 or CFU-GM. Chromatography of HL-60 CM on Ultrogel AcA54 showed a single peak of HL-60 stimulating activity of apparent molecular weight 13,000. The ability of HL-60 cells to elaborate this activity provides a possible explanation for their proliferation at higher cell densities. Autostimulation may prove to be important in the high growth potential of other cell populations that undergo unrepressed proliferation.     

Simulation and its role in medical education

Medical education is increasingly laying emphasis on a curriculum based on cognitive, psychomotor, and affective domains of learning which were originally proposed nearly 50 years ago. These reforms are framed around best standards of care, error management and patient safety, patient autonomy, and resource allocation. There is a worldwide shift in the method of medical education towards experiential (‘hands-on’) medical learning; however, applying this concept to real patients is less acceptable to society and is subject to legal and ethical issues.