Intestinal permeability in the newborn

Passive intestinal permeability in 33 newborn babies was studied using feeds containing lactulose and mannitol. Each marker is thought to pass across the gut wall by a different route; lactulose by a paracellular and mannitol by a transcellular pathway. Neither is metabolised and both are wholly and solely excreted by the kidney; urinary recovery is a measure of the intestinal uptake. Babies born before 34 weeks' gestation exhibited a higher intestinal permeability to lactulose than more mature babies, and all preterm babies showed an appreciable decline in lactulose absorption during the first week of oral feeds. Babies of 34 to 37 weeks' gestation achieved a 'mature' intestinal permeability to lactulose within four days of starting oral feeds. These findings may reflect the immaturity of the gut of the preterm baby rather than a process essential to adaptation to enteral nutrition.     

Characterization of the mechanism underlying stonustoxin-mediated relaxant response in the rat aorta in vitro

Stonustoxin (SNTX) is a lethal factor isolated from the venom of the stonefish Synanceja horrida. Although SNTX exhibits a multitude of biological activities, the primary cause of death upon administration of the toxin is attributed to marked hypotension. We investigated the possible mechanisms underlying the vascular hyporeactivity of this novel toxin. Cumulative doses of SNTX (5-320 ng/mL) induced concentration-dependent relaxation in phenylephrine (PE)--precontracted rat aortic rings with intact endothelium. Endothelium removal abolished the relaxation induced by SNTX. Tetraethylammonium (TEA), an inhibitor of K(+) channels, partially inhibited SNTX-induced relaxation. Similarly, SNTX-induced relaxation was partially attenuated by the SP receptor antagonist (NATB), whereas the inducible iNOS inhibitor, AMT-HCl, completely abolished the relaxation caused by SNTX. From the results obtained, it can be postulated that a component of SNTX-mediated vasorelaxation is via binding of either SNTX or SP to the SP receptors that are located on the endothelial cells. Occupation of these SP receptors causes subsequent production of NO and activation of K(+) channels, thus leading to vasorelaxation of the rat aortic rings.     

A tumour that secretes glucagon-like peptide-1 and somatostatin in a patient with reactive hypoglycaemia and diabetes

Glucagon-like peptide 1 (GLP-1), an insulinotropic hormone normally synthesised in the intestinal mucosa and released in response to a meal, is essential for normal glucose homoeostasis. There is much interest in the use of GLP-1 to treat diabetes, since the risk of hypoglycaemia is thought to be low. We report an instance of a 45-year-old woman with a GLP-1 and somatostatin secreting neuroendocrine tumour who presented with reactive hypoglycaemia and hyperglycaemia, but who was subsequently cured by surgery. This case, of a neuroendocrine tumour secreting GLP-1 and causing reactive hypoglycaemia, indicates a potential adverse effect of GLP-1 therapy for diabetes.     

Nutritional status of teenage female competitive figure skaters

OBJECTIVE: To assess the nutritional status of female competitive figure skaters during preseason, competitive season, and off-season. SUBJECTS: Eighteen female competitive figure skaters, age range 14 to 16 years, from the New England region. STATISTICS: Data was analyzed by repeated measures analysis of variance, Duncan Multiple Range Tests, one-sample t tests, and confidence intervals. DESIGN: Nutrient intakes were determined from 3-day diet records. Body composition was assessed through heights, weights, and underwater weighing. Blood samples were drawn for analysis of selected indexes of nutritional status. RESULTS: Height and weight did not differ significantly among the seasons. Body fat was 1.1 kg higher off-season compared with preseason. Energy intake over the 3 seasons did not vary significantly (mean preseason: 1,678 kcal/day; competitive season, 1,630 kcal/day; off-season: 1,673 kcal/day) (P>.05). During the competitive season 78%, 50%, and 44% of the skaters had intakes less than 67% of RDA for folate, iron, and calcium, respectively. Most of the biochemical indexes of nutritional status were within normal limits. CONCLUSIONS: The results indicate that teenage female skaters have relatively low energy intake and inadequate intakes of certain nutrients, which may account for some of the observed seasonal variations in blood markers of nutritional status. These findings point to the need for nutrition education for these athletes, especially during their competitive season when nutritional status may be compromised.     

Selective loss of chromosome 11 in pheochromocytomas associated with the VHL syndrome

By using comparative genomic hybridization (CGH), we characterized the genetic profiles of 36 VHL-related pheochromocytomas. We then compared the results with those of sporadic and MEN 2-related pheochromocytomas. In 36 VHL-related tumors, loss of chromosome 3 and chromosome 11 were found in 34 tumors (94%) and 31 tumors (86%), respectively. There was significant concordance of deletions in chromosomes 3 and 11 (Kappa=0.64, P=0.0095), suggesting that they are involved in two different but necessary and complementary genetic pathways. The loss of chromosome 11 appeared to be specific for VHL-related pheochromocytoma as it was not present in any of the 10 VHL-related CNS hemangioblastomas studied and was significantly less common when compared with (a) sporadic pheochromocytomas from previously published results (13%; P=<0.0001), and (b) MEN 2-related pheochromocytomas from this and previously published studies (30%; P=0.0012). In summary, this is the first report of a novel consistent genetic alteration that is selected and specific for VHL-related pheochromocytoma, besides the two hits of the VHL gene.     

Reversible findings of restricted diffusion in 5‐flourouracil neurotoxicity

A 35‐year‐old woman presented with neurotoxicity correlated to an i.v. regimen of 5‐fluorouracil as episodes of acute confusional state and abnormalities of symmetrically restricted diffusion in the periventricular white matter and corpus callosum. On discontinuing the medication, the areas of severely restricted diffusion had entirely resolved, with minimal residual T2 signal abnormality. In this case, immediate discontinuation of the chemotherapeutic agent apparently reversed the patient's symptoms and findings on MRI. The scant information available in the published literature regarding this phenomenon is reviewed with regard to 5‐fluorouracil.     

Mitomycin-C induced hemolytic uremic syndrome: a case report and literature review

Hemolytic uremic syndrome spontaneously arises in a few patients with advanced cancer, but it is more commonly related to the use of certain chemotherapeutic agents. Mitomycin-C is, etiologically, the most common causative agent inducing hemolytic uremic syndrome, in a dose dependent manner. We report this syndrome, attributable to mitomycin-C at a cumulative dose of 40 mg/m2, in a gastric cancer patient. A 42-year-old female with stage III gastric cancer underwent radical gastrectomy and was given mitomycin-C at 10 mg/m2 intravenously every four weeks as adjuvant therapy. Hemolytic uremic syndrome was diagnosed three months after the last dose of mitomycin-C administration. The most prominent symptoms included pallor, hypertension and anasarca, with laboratory evidence of microangiopathic hemolytic anemia, azotemia and hyperkalemia. Her disease was progressive, but fortunately stabilized after staphylococcus column A dialysis. Her disease remained in remission for 24 months from the time of diagnosis, and then relapsed in the form of peritoneal carcinomatosis with partial intestinal obstruction.      

Optimization of coplanar six-field techniques for conformal radiotherapy of the prostate

PURPOSE: To determine the optimal coplanar treatment technique for six-field conformal radiotherapy of prostate only (PO) or prostate plus seminal vesicles (PSV). METHODS AND MATERIALS: A series of 6-MV six-field coplanar treatment plans were created for PO and PSV volumes in 10 patients prescribed to both 64 and 74 Gy. All plans consisted of laterally-symmetric anterior oblique, lateral, and posterior oblique fields. The posterior oblique fields were varied through 20-45 degrees relative to the lateral fields, and for each of these angles, the anterior oblique fields were varied through 25-65 degrees relative to lateral. The plans were compared by means of rectal volumes irradiated to 80% or more of the prescribed dose (V80); normal tissue complication probability (NTCP) for rectum, bladder, and femoral heads; and tumor control probability (TCP). Femoral head tolerance was designated as 52 Gy to no more than 10% volume. RESULTS: For the PO group, anterior oblique fields at 50 degrees from lateral and posterior oblique fields at 25 degrees from lateral produced the lowest V80, together with femoral head doses which were appropriate for most patients (V80 = 24.4+/-5.3% [1 SD]). Compared to a commonly-used six-field (reference) plan with both anterior and posterior oblique fields at 35 degrees from lateral (V80 = 26.3+/-5.9%), this represented an improvement (p = 0.001). For the PSV group, the optimal anterior and posterior oblique fields were at 65 degrees and 30 degrees from lateral, respectively (V80 = 47.5+/-6.3%). Relative to the reference plan (V80 = 49.4+/-5.6%), this was a marginal improvement (p = 0.07). CONCLUSION: The optimized six-field plans provide increased rectal sparing at both standard and escalated doses. Moreover, the gain in TCP resulting from dose escalation can be achieved with a smaller increase in rectal NTCP using the optimized six-field plans.