Glutamine-enriched enteral nutrition in very low birth weight infants. Design of a double-blind randomised controlled trial [ISRCTN73254583]

Background

Enteral feeding of very low birth weight (VLBW) infants is a challenge, since metabolic demands are high and administration of enteral nutrition is limited by immaturity of the gastrointestinal tract. The amino acid glutamine plays an important role in maintaining functional integrity of the gut. In addition, glutamine is utilised at a high rate by cells of the immune system. In critically ill patients, glutamine is considered a conditionally essential amino acid. VLBW infants may be especially susceptible to glutamine depletion as nutritional supply of glutamine is limited in the first weeks after birth. Glutamine depletion has negative effects on functional integrity of the gut and leads to immunosuppression. This double-blind randomised controlled trial is designed to investigate the effect of glutamine-enriched enteral nutrition on feeding tolerance, infectious morbidity and short-term outcome in VLBW infants. Furthermore, an attempt is made to elucidate the role of glutamine in postnatal adaptation of the gut and modulation of the immune response.

Methods

VLBW infants (gestational age <32 weeks and/or birth weight <1500 g) are randomly allocated to receive enteral glutamine supplementation (0.3 g/kg/day) or isonitrogenous placebo supplementation between day 3 and 30 of life. Primary outcome is time to full enteral feeding (defined as a feeding volume ≥ 120 mL/kg/day). Furthermore, incidence of serious infections and short-term outcome are evaluated. The effect of glutamine on postnatal adaptation of the gut is investigated by measuring intestinal permeability and determining faecal microflora. The role of glutamine in modulation of the immune response is investigated by determining plasma Th1/Th2 cytokine concentrations following in vitro whole blood stimulation.

     

Laparoscopic and Retroperitoneoscopic Treatment of Pheochromocytomas and Retroperitoneal Paragangliomas: Results of 161 Tumors in 126 Patients

Background Laparoscopic and retroperitoneoscopic excisions of pheochromocytomas and retroperitoneal paragangliomas are challenging surgical procedures because of extensive intraoperative catecholamine release, extreme vascularization, and demanding localization. Materials In a prospective clinical study 161 chromaffine neoplasias (134 pheochromocytomas, 27 paragangliomas) were removed endoscopically in 126 patients (67 males, 59 females, age 41.7 ± 16.4 years; 130 operations). Six patients showed multiple (2–5) tumors. Tumor size ranged from 0.5 to 12 cm (mean 3.5 ± 1.9 cm). Forty-two patients suffered from hereditary diseases. Twenty-four patients had bilateral adrenal diseases; in 14 patients pheochromocytomas were removed on both sides synchroneously. Ten neoplasias were local or loco-regional recurrences (7 pheochromocytomas, 3 paragangliomas). The laparoscopic route was chosen in 16 operations; the retroperitoneoscopic technique was performed in 128 others. Partial adrenalectomies were performed in 57 operations (in all but one of the patients with bilateral disease). High-dosage α-blockade with phenoxybenzamine was routinely used. Results and Discussion Conversion to open surgery occurred once. Perioperative complications were minor (17%); mortality was zero. Operating time for unilateral retroperitoneoscopically removed primary pheochromocytomas (n = 113) was 82 ± 49 minutes (range: 20–300 minutes) and depended on tumor size (< 3 cm vs. ≥ 3 cm; P < 0.05) and gender (P < 0.001), but not on extent of resection (partial vs. total, P = 0.266). Operating time for paragangliomas ranged from 55 to 600 minutes. Median blood loss was 20 ml. Median duration of postoperative hospitalization was 4 days. In 22 of 24 patients with bilateral disease, complete preservation of cortical function was achieved. Locoregional and/or distant metastatic recurrence were found in 5 patients. Conclusions Endoscopic removal of solitary, bilateral, multiple, and recurrent pheochromocytomas and retroperitoneal paragangliomas is feasible and safe, but surgeons need extensive experience in minimally invasive techniques, as well as in endocrine surgery.     

Detection of myocardial ischemia in vitro by computed tomography

The applicability of CT in the delineation of ischemic myocardium is defined. Twenty-six dogs had their left anterior descending coronary artery occluded, and radiolabeled microspheres were injected into the left atrium to measure myocardial blood flow. From 30 minutes to 7 weeks after coronary occlusion the hearts were excised and scanned in a CT head scanner. An unbiased observer divided selected CT scans slices into normal, abnormal, and borderline areas of attenuation coefficients; these were correlated with blood flow measurements and a progressive decrease in flow from normal to borderline and borderline to abnormal segments was found. As early as 2 hours after coronary arterial occlusion, areas of reduced attenuation coefficient, corresponding to regions of reduced blood flow, were seen. Areas of increased attenuation were seen in regions containing microcalcifications and fibrosis in several longer term experiments. Areas of reduced blood flow were visible immediately after coronary arterial occlusion with intravenous iodinated contrast material (1 ml/kg). CT detection of regions of reduced blood flow defined by radiolabeled microsphere is a promising means of detecting and sizing myocardial infarcts.