Acute gastrointestinal bleeding

Diagnosis and intervention in pediatric GI bleeding is the shared responsibility of pediatric endoscopists, radiologists, and surgeons. Brisk hemorrhage, though alarming, is most often self-limited; few cases require urgent surgery before diagnostic evaluation is accomplished. The choice between endoscopic and radiographic evaluation varies with the differential diagnoses being considered and with local referral patterns. Many imaging options exist for assessing GI bleeding in children, but these options are generally narrowed by clinical history and age-appropriate differential possibilities.     

Pulmonary contusion: review of the clinical entity

Pulmonary contusion is a common lesion occurring in patients sustaining severe blunt chest trauma. Alveolar hemorrhage and parenchymal destruction are maximal during the first 24 hours after injury and then usually resolve within 7 days. The diagnosis of traumatic lung injury is usually made clinically with confirmation by chest x-ray films. The chest computed tomography scan is highly sensitive in identifying pulmonary contusion and may help predict the need for mechanical ventilation. Respiratory distress is common after lung trauma, with hypoxemia and hypercarbia greatest at about 72 hours. Although management of patients with pulmonary contusion is supportive, pneumonia and adult respiratory distress syndrome with long-term disability occur frequently.     

Vasoactive intestinal peptide stimulation of human trabecular meshwork cell growth

PURPOSE: To demonstrate that vasoactive intestinal peptide (VIP), a 28-amino acid neuropeptide, is a growth factor of human trabecular meshwork (TM) cells in culture and in a corneoscleral explant organ culture treated with laser trabeculoplasty (LTP). METHODS: Proliferating human TM cells in cell cultures were incubated with VIP for 20 hours, followed by total cell number determination, using a Coulter counter. The percentage of proliferating TM cells was assessed, using an antibody against the proliferating cell nuclear antigen (PCNA). To test the growth effect of VIP on TM cells in situ, corneoscleral explants in organ cultures were first treated with argon LTP to initiate TM-cell proliferation and then were exposed to VIP for 48 hours. The mitotic TM cells were demonstrated immunocytochemically, using anti-PCNA in paraffin sections of the explants; and the total number of TM cells was determined after paraffin sections were counterstained by hematoxylin. RESULTS: Vasoactive intestinal peptide dose-dependently stimulated the proliferation of TM cells in cell culture. Treatment with 5 x 10(-10) M VIP resulted in a maximal increase of 40% in cell number. The effect of VIP was blocked by a VIP antagonist. The number of PCNA-stained TM cells and the total cell number in the TM in LTP-treated corneoscleral explants were increased by VIP. CONCLUSIONS: Exogenously applied VIP stimulated the proliferation of human TM cells in subconfluent cultures and in LTP-treated corneoscleral explants. In that LTP has been shown to increase the number of TM cells in situ, the growth stimulatory effect of VIP may help enhance this therapy.     

Endogenous glucose production following injury increases with age

To evaluate the influence of aging on the increase in endogenous glucose production that follows injury, we studied 22 fully resuscitated, clinically stable, previously healthy patients aged < or = 30 yr or > or = 60 yr admitted to hospital following injury, and 11 healthy volunteers in the same age groups. Endogenous glucose production was determined using a primed constant infusion of D-glucose-6,6-2d2. Urine cortisol and C-peptide were markedly higher in patients than volunteers (both P < 0.01), and urine C-peptide was lower in older than in younger patients (P < 0.05). Urine cortisol increased as a function of the interaction of age and Injury Severity Score (ISS) (r2 = 0.40, P < 0.001). Intracellular water was markedly lower and extracellular water greater in patients compared with volunteers (both P < 0.001), reflecting the loss of body cell mass and expansion of the extracellular space following injury. Endogenous glucose production (milligrams per minute per liter intracellular water) was best described as a function of ISS and age-ISS interaction (r2 = 0.35, all P < 0.05), and was increased 56% and 78% in younger and older patients, respectively, in comparison with the respective volunteer groups. Endogenous glucose production following injury increases in relation to the severity of injury and patient age. Greater cortisol elaboration and diminished insulin secretion in older patients may contribute to this age effect.