Regulation of alpha1-proteinase inhibitor release by proinflammatory cytokines in human intestinal epithelial cells.

alpha1-Proteinase inhibitor (alpha1-PI) is the main serine proteinase inhibitor in human plasma. Apart from its synthesis in the liver, this anti-inflammatory protein is also synthesized by and excreted from human intestinal epithelial cells. Antiinflammatory actions of alpha1-PI are thought to be of relevance in the pathogenesis of inflammatory bowel disease. To investigate the role of macrophage-derived cytokines on alpha1-PI secretion from intestinal epithelial cells, we cultured Caco-2 cells until differentiation (14 days in culture) on permeable filter supports. Monolayers of differentiated Caco-2 cells were then co-cultured with human peritoneal macrophages, grown on plastic in the basolateral chamber. Under these conditions, alpha1-PI secretion from Caco-2 cells was enhanced by 45%, probably by a direct action of macrophage-derived cytokines on Caco-2 cells. To extend this observation further, we treated differentiated Caco-2 cells with macrophage-derived proinflammatory cytokines (IL-1beta, IL-8, TNF-alpha), as well as with lymphocyte-derived cytokines IL-2, IL-6 and IFN-gamma. As early as after 24h treatment, IL-2 and IL-8 induced a significant and dose-dependent increase of alpha-1-PI secretion into cell culture medium; this effect was completely reversed after immunoneutralization by the antibodies against IL-2 and IL-8 alpha1-PI secretion was only slightly decreased after treatment with IFN-gamma, while IL-1beta, IL-6 and TNF-alpha had no effect. alpha1-PI secretion correlated well with the expression of this protein in differentiated Caco-2 cells after cytokine treatment, as confirmed by Western blot. Our data imply that, in vitro, alpha1-PI secretion in enterocyte-like Caco-2 cells is up-regulated by IL-2 and IL-8. Our results suggest that both lymphocyte- and macrophage-derived cytokines regulate secretion of the anti-inflammatory protein alpha1-PI in intestinal epithelial cells.

The delivery of salts to the xylem. Three types of anion conductance in the plasmalemma of the xylem parenchyma of roots of barley.

To explore possible pathways for anions to enter the xylem in the root during the transport of salts to the shoot, we used the patch-clamp method on protoplasts prepared from the xylem parenchyma of barley (Hordeum vulgare L.) plants. K(+) currents were suppressed by tetraethylammonium or N-methylglucamine in the solutions in the pipette and the bath, and the permeating anions were Cl(-) or NO(3)(-). We recorded the activities of three distinct anion conductances: (a) an inwardly rectifying anion channel (X-IRAC), characterized by activation at hyperpolarization and open times of up to several seconds; (b) a quickly activating anion conductance (X-QUAC), important for anion efflux at voltages between -50 mV and the equilibrium potential of the prevailing anion; and (c) a slowly activating anion conductance (X-SLAC), activating above -100 mV. Both X-IRAC and X-QUAC were permeable for Cl(-) and NO(3)(-); X-QUAC was also permeable for malate. The occurrence of X-IRAC became more frequent with an increase in cytoplasmic Ca(2+), while the occurrence of X-QUAC decreased. Anion currents through X-SLAC, and particularly through X-QUAC, were estimated to be large enough to account for reported rates of xylem loading, which is in accordance with the notion that xylem loading is a passive process.

Rates of sugar uptake by guard cell protoplasts of pisum sativum L. Related To the solute requirement for stomatal opening

We wished to determine whether the capacity of the sugar uptake mechanisms of guard cells of the Argenteum mutant of pea (Pisum sativum L.) sufficed to support a concurrent stomatal opening movement. Sugar uptake by guard cell protoplasts was determined by silicone-oil-filtering centrifugation. The protoplasts took up [(14)C]glucose, [(14)C]fructose, and [(14)C]sucrose (Suc), apparently in symport with protons. Mannose, galactose, and fructose competed with Glc for transport by a presumed hexose carrier. The uptake of Glc saturated with a K(m) of 0.12 mM and a V(max) of 19 fmol cell(-1) h(-1). At external concentrations <1 mM, the uptake of Suc was slower than that of Glc. It exhibited a saturating component with a K(m) varying between 0.25 and 0.8 mM and a V(max) between 1 and 10 fmol cell(-1) h(-1), and at external concentrations >1 mM, a non-saturating component. At apoplastic sugar concentrations below 4 mM, sugar import was estimated to be mainly in the form of hexoses and too slow to support a simultaneous stomatal opening movement. If, however, during times of high photosynthesis and transpiration, the apoplastic Suc concentration rose and entered the range of non-saturating import, absorbed Suc could replace potassium malate as the osmoticum for the maintenance of stomatal opening.

Eosinophilic gastroenteritis mimicking idiopathic hypertrophic pyloric stenosis.

We report two infants with eosinophilic gastroenteritis (EG). This rare disease can mimic the clinical symptoms and US appearance of idiopathic hypertrophic pyloric stenosis (IHPS). US examination of the antropyloric region with a high-frequency linear transducer can assist in the differentiation of EG from IHPS, which is important because the therapeutic approaches are completely different. Eosinophilic gastroenteritis should be considered in the differential diagnosis of IHPS, especially when there has been an ineffective pyloromyotomy.

Hyperbilirubinemia associated with a cystic abdominal mass in a 6-week-old girl: case report.

Abdominal cysts in girls are frequently observed by abdominal ultrasound (US) and are usually ovarian. In this case a cystic structure located in the right abdomen was seen in a female newborn without symptoms and was initially described as a possible ovarian cyst. Frequent US examinations showed an increase in volume and diameter, and temporary, recurring episodes of hyperbilirubinemia were observed. The US scans showed no relationship to the biliary tree. During a diagnostic laparoscopy, a cystic structure attached to the pyloric region was seen. A laparotomy revealed a cystic duplication of the stomach, which could be resected completely. The finding is discussed emphasizing the importance of clinical findings and diagnostic methods in the diagnosis and management of abdominal cystic masses in females.

Solute accumulation and decreased photosynthesis in leaves of potato plants expressing yeast-derived invertase either in the apoplast, vacuole or cytosol.

Potato (Solanum tuberosum cv. Désirée) plants expressing yeast invertase directed either to the apoplast, vacuole or cytosol were biochemically and physiologically characterised. All lines of transgenic plants showed similarities to plants growing under water stress. Transformants were retarded in growth, and accumulated hexoses and amino acids, especially proline, to levels up to 40-fold higher than those of the wild types. In all transformants rates of CO2 assimilation and leaf conductance were reduced. From the unchanged intercellular partial pressure of CO2 and apoplastic cis-abscisic acid (ABA) content of transformed leaves it was concluded that the reduced rate of CO2 assimilation was not caused by a limitation in the availability of CO2 for the ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco). In the transformants the amount of Rubisco protein was not reduced, but both activation state and carboxylation efficiency of photosynthesis were lowered. In vacuolar and cytosolic transformants this inhibition of Rubisco might be caused by a changed ratio of organic bound and inorganic phosphate, as indicated by a doubling of phosphorylated intermediates. But in apoplastic transformants the pattern of phosphorylated intermediates resembled that of leaves of water-stressed potato plants, although the cause of inhibition of photosynthesis was not identical. Whereas in water-stressed plants increased contents of the phytohormone ABA are supposed to mediate the adaptation to water stress, no contribution of ABA to reduction of photosynthesis could be detected in invertase transformants.

Ischaemic stroke in infancy and childhood: role of the Arg506 to Gln mutation in the factor V gene.

Dahlbäck et al. recently described in vitro resistance to the anticoagulant response of activated protein C (APC), in the majority of cases associated with the Arg506 to Gln point mutation in the factor V gene in thrombophilic patients. To determine to what extent this common gene mutation affects the risk of childhood stroke, its occurrence was prospectively investigated in a population of children with ischaemic stroke. Over a 2-year period the Arg506 to Gln mutation, factor V, protein C, protein S, antithrombin, antiphospholipid antibodies and lipoprotein (a) [Lp(a)] were measured in 14 infants and children with acute ischaemic stroke. Heterozygous factor V Leiden mutation (n = 4), homozygous factor V Leiden mutation (n = 1), protein C deficiency type I (n = 3) and increased Lp(a) (n = 2) were diagnosed in the children investigated. Seven of 14 patients showed an underlying disease and additionally risk factors were present in nine of 14 children. Data of this study indicate that deficiencies in the protein C anticoagulant pathway play an important role in the aetiology of childhood stroke. However, additional triggering factors may promote early manifestation of thromboembolism in children with inherited defects of clotting inhibitors.

Resistance to activated protein C (APCR) in children with venous or arterial thromboembolism.

Resistance to activated protein C (APCR), in the majority of cases due to the point mutation Arg 506 Gln of the factor V gene, has emerged as the most important hereditary cause of venous thromboembolism. Using an activated thromboplastin time (aPTT) based method in the presence of APC together with a DNA technique based on the polymerase chain reaction, we investigated 37 children with venous (V: n=19) or arterial (A: n=18) thromboembolism and 196 age-matched healthy controls for the presence of this mutation. In the control group 10 children were detected to be heterozygous for the factor V Leiden mutation, indicating a prevalence of 5.1%. 10/19 children (52%) with venous thrombosis and 7/18 (38%) patients with arterial thromboembolism showed the common factor V gene mutation. Additional inherited coagulation disorders were found in 1/10 (V:10%) and 2/7 (A:28%) APC-resistant patients. Inherited coagulation disorders without APCR were diagnosed in 3/9 (V: 33%) and 2/11 (A:18%) children. Furthermore, we diagnosed exogenous risk factors in 6/10 (V: 60%) and 2/7 (A: 28%) children with thrombosis and APCR. These data are evidence that APCR combined with exogenous reasons may play an important role in the early manifestation of thromboembolism during infancy and childhood.

Sonographic features of Hashimoto thyroiditis in childhood.

Fifty-seven sonograms of 18 children with Hashimoto thyroiditis were retrospectively assessed. Thirty-three examinations (in 12 patients) showed thyroid glands which were more reflective than adjacent strap muscles, 22 studies (in eight patients) demonstrated glands of equal reflectivity and two examinations (in one child) depicted thyroid glands of lower reflectivity than muscle. The most frequent ultrasound appearance consisted of 2-5 mm echopenic lesions generally distributed throughout large poorly-defined hyperreflective glands. In serial examinations no correlation was found between laboratory indexes of thyroid status and sonographic findings.

[Assessment of the resectability of Wilms' tumors in childhood]. / Beurteilung der Resektabilität von Wilmstumoren im Kindesalter.

Over the last ten years 62 children were operated for renal tumours. The therapeutic aim in Wilms' tumours is complete macroscopic resection of the primary tumour, assessing resectability as accurately as possible. Overestimating surgical possibilities may lead to intraoperative rupture of the tumour (three cases), while overestimating local tumour extent may result in too much preoperative chemotherapy, which resulted in the life-threatening complication of venous occlusive disease of the hepatic veins (VOD) in three infants. The assessment of resectability may become particularly problematic in bilateral (six cases) or multifocal Wilms' tumours (two cases), and in nephroblastomatosis (two cases), i.e. the persistence of embronal renal tissue, a facultatively precancerous lesion, which requires quarterly sonographic controls and which induced a second metachronous contralateral Wilms' tumour in one child.