Sensory integration intervention and the development of the premature infant: A controlled trial.

BACKGROUND: Premature infants are at risk of sensory processing difficulties and developmental delays due to an immature central nervous system and possible episodes of medical instability, discomfort, pain and stress during the first weeks or months after birth. OBJECTIVE: To investigate the effect of Ayres Sensory Integration (ASI) on the development of premature infants in the first 12 months of life. METHODS: A pre-/post-test experimental design was used to randomly divide 24 premature infants from a low socioeconomic setting in Bloemfontein, South Africa, into experimental and control groups after being matched by corrected age and gender. Developmental status was determined with the Bayley III Scales of Infant and Toddler Development, the Test of Sensory Functions in Infants and the Infant/Toddler Sensory Profile. The experimental group received 10 weeks of ASI intervention. RESULTS: ASI intervention had a positive effect on the sensory processing and development of premature infants, especially in terms of cognitive, language and motor development. CONCLUSIONS: ASI intervention at an early age enhances the developmental progress of premature infants.

Enfermedad diverticular del colon: tratamiento quirúrgico. Nuestra experiencia / Diverticular disease of the colon: surgical treatment. Our experience

Objetivo: Evaluar retrospectivamente la experiencia en el tratamiento quirúrgico de la enfermedad diverticular del colon durante los últimos años. Lugar: Hospital de comunidad. Material y Métodos: Revisión de 108 historias clínicas de pacientes operados portadores de enfermedad diverticular del colon. Diseño retrospectivo, observacional, transversal. Las variables analizadas fueron las siguientes: Motivo de consulta e indicación quirúrgica, métodos complementarios de diagnóstico en relación al cuadro clínico, tipo de cirugía y morbimortalidad. Resultados: La causa más frecuente de consulta y de indicación quirúrgica fue la sigmoiditis diverticular, de los cuales 41 tenían signos endoscópicos positivos para indicar tratamiento quirúrgico. El 90,7 por ciento de la serie se operaron en forma electiva, mientras que en el 9,3 por ciento se realizó cirugía de urgencia. La morbilidad global fue del 19 por ciento y la mortalidad del 0,9 por ciento. Conclusiones. Coincidimos con la tendencia mundial de realizar resecciones primarias con o sin derivación

Enfermedad diverticular del colon: tratamiento quirúrgico. Nuestra experiencia / Diverticular disease of the colon: surgical treatment. Our experience

Objetivo: Evaluar retrospectivamente la experiencia en el tratamiento quirúrgico de la enfermedad diverticular del colon durante los últimos años. Lugar: Hospital de comunidad. Material y Métodos: Revisión de 108 historias clínicas de pacientes operados portadores de enfermedad diverticular del colon. Diseño retrospectivo, observacional, transversal. Las variables analizadas fueron las siguientes: Motivo de consulta e indicación quirúrgica, métodos complementarios de diagnóstico en relación al cuadro clínico, tipo de cirugía y morbimortalidad. Resultados: La causa más frecuente de consulta y de indicación quirúrgica fue la sigmoiditis diverticular, de los cuales 41 tenían signos endoscópicos positivos para indicar tratamiento quirúrgico. El 90,7 por ciento de la serie se operaron en forma electiva, mientras que en el 9,3 por ciento se realizó cirugía de urgencia. La morbilidad global fue del 19 por ciento y la mortalidad del 0,9 por ciento. Conclusiones. Coincidimos con la tendencia mundial de realizar resecciones primarias con o sin derivación (AU)

Fibroblast growth factor-10 upregulates Na,K-ATPase via the MAPK pathway.

We studied the effects of fibroblast growth factor (FGF-10) on alveolar epithelial cell (AEC) Na,K-ATPase regulation. Within 30 min FGF-10 increased Na,K-ATPase activity and alpha1 protein abundance by 2.5-fold at the AEC plasma membrane. Pretreatment of AEC with the mitogen-activated protein kinase (MAPK) inhibitor U0126, a Grb2-SOS inhibitor (SH3-b-p peptide), or a Ras inhibitor (farnesyl transferase inhibitor (FTI 277)), as well as N17-AEC that express a Ras dominant negative protein each prevented FGF-10-mediated Na,K-ATPase recruitment to the AEC plasma membrane. Accordingly, we provide first evidence that FGF-10 upregulates (short-term) the Na,K-ATPase activity in AEC via the Grb2-SOS/Ras/MAPK pathway.

Dopamine increases lung liquid clearance during mechanical ventilation.

Short-term mechanical ventilation with high tidal volume (HVT) causes mild to moderate lung injury and impairs active Na+ transport and lung liquid clearance in rats. Dopamine (DA) enhances active Na+ transport in normal rat lungs by increasing Na+-K+-ATPase activity in the alveolar epithelium. We examined whether DA would increase alveolar fluid reabsorption in rats ventilated with HVT for 40 min compared with those ventilated with low tidal volume (LVT) and with nonventilated rats. Similar to previous reports, HVT ventilation decreased alveolar fluid reabsorption by ~50% (P < 0.001). DA increased alveolar fluid reabsorption in nonventilated control rats (by ~60%), LVT ventilated rats (by approximately 55%), and HVT ventilated rats (by ~200%). In parallel studies, DA increased Na+-K+-ATPase activity in cultured rat alveolar epithelial type II cells (ATII). Depolymerization of cellular microtubules by colchicine inhibited the effect of DA on HVT ventilated rats as well as on Na+-K+-ATPase activity in ATII cells. Neither DA nor colchicine affected the short-term Na+-K+-ATPase alpha1- and beta1-subunit mRNA steady-state levels or total alpha1- and beta1-subunit protein abundance in ATII cells. Thus we reason that DA improved alveolar fluid reabsorption in rats ventilated with HVT by upregulating the Na+-K+-ATPase function in alveolar epithelial cells.

Dopamine regulates Na-K-ATPase in alveolar epithelial cells via MAPK-ERK-dependent mechanisms.

Dopamine (DA) increases lung edema clearance by regulating vectorial Na+ transport and Na-K-ATPase in the pulmonary epithelium. We studied the role of the mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) pathway in the DA regulation of Na-K-ATPase in alveolar epithelial cells (AEC). Incubation of AEC with DA resulted in a rapid stimulation of ERK activity via dopaminergic type 2 receptors. Analysis of total RNA and protein showed a 1.5-fold increase in the Na-K-ATPase beta1-subunit mRNA levels and up to a fivefold increase in beta1-subunit protein abundance after DA stimulation, which was blocked by the MAPK kinase (MEK) inhibitors PD-98059 and U-0126. Also, the DA-ERK pathway stimulated the synthesis of a green fluorescent protein reporter gene driven by the beta1-subunit promoter, which indicates that DA regulates the Na-K-ATPase beta1-subunit at the transcriptional level. The DA-mediated increase in beta1-subunit mRNA protein resulted in an increase in functional Na pumps in the basolateral membranes of alveolar type II cells. These results suggest that the MAPK-ERK pathway is an important mechanism in the regulation of Na-K-ATPase by DA in the alveolar epithelium.

A novel role for protein phosphatase 2A in the dopaminergic regulation of Na,K-ATPase.

Stimulation of dopaminergic type 1 (D(1)) receptors increases lung edema clearance by regulating Na,K-ATPase function in the alveolar epithelium. We studied the role of serine/threonine protein phosphatases in the Na,K-ATPase regulation by D(1) agonists in A549 cells. We found that low doses of the type 1/2A protein phosphatase inhibitor okadaic acid as well as SV40 small t antigen transiently transfected into A549 cells prevented the D(1) agonist-induced increase in Na,K-ATPase activity and translocation from intracellular pools to the plasma membrane. This was associated with a rapid and transient increase in protein phosphatase 2A activity. We conclude that D(1) stimulation regulates Na,K-ATPase activity by promoting recruitment of Na,K-ATPases from intracellular pools into the basolateral membranes of A549 cells via a type 2A protein phosphatase.

beta-adrenergic stimulation restores rat lung ability to clear edema in ventilator-associated lung injury.

Mechanical ventilation with high tidal volume (HVT) causes lung injury and decreases the lung's ability to clear edema in rats. beta-adrenergic agonists increase active Na(+) transport and lung edema clearance in normal rat lungs by stimulating apical Na(+) channels and basolateral Na,K-ATPase in alveolar epithelial cells. We studied whether beta-adrenergic agonists could restore lung edema clearance in rats ventilated with HVT (40 ml/kg, peak airway pressure of 35 cm H(2)O) for 40 min. The ability of rat lungs to clear edema decreased by approximately 50% after 40 min of HVT ventilation. Terbutaline (TERB) and isoproterenol (ISO) increased lung edema clearance in control nonventilated rats (from 0.50 +/- 0. 02 ml/h to 0.81 +/- 0.04 ml/h and 0.99 +/- 0.05 ml/h, respectively) and restored the lung's ability to clear edema in HVT ventilated rats (from 0.25 +/- 0.03 ml/h to 0.64 +/- 0.02 ml/h and 0.88 +/- 0. 09 ml/h, respectively). Disruption of cell microtubular transport system by colchicine inhibited the stimulatory effects of ISO in HVT ventilated rats, whereas beta-lumicolchicine did not affect beta-adrenergic stimulation. The Na,K-ATPase alpha(1)- and beta(1)-subunit mRNA steady state levels were not affected by incubation with ISO for 60 min in alveolar type II cells isolated from control and HVT ventilated rats. The data suggest that beta-adrenergic agonists increased alveolar fluid reabsorption in rats ventilated with HVT by promoting recruitment of ion-transporting proteins from intracellular pools to the plasma membrane of alveolar epithelial cells.

Stimulation of the dopamine 1 receptor increases lung edema clearance.

We previously reported that lung edema clearance was stimulated by dopamine (DA). The purpose of this study was to determine whether the DA-mediated stimulation of edema clearance occurs via an adrenergic or dopaminergic regulation of alveolar epithelial Na, K-ATPase. When isolated perfused rat lungs were coinstilled with DA and SCH 23390 (a specific D(1) receptor antagonist), there was a dose-dependent attenuation of the stimulatory effects of DA. Coinstillation with S-sulpiride (a specific D(2) receptor antagonist) or propranolol (a beta-adrenergic antagonist) did not alter DA-stimulated clearance. Similarly, the specific dopaminergic D(1) agonist fenoldopam increased lung edema clearance, but quinpirole (a specific dopaminergic D(2) agonist) did not. (125)I-SCH 23982 binding studies suggested that D(1) receptors are expressed on alveolar type II (ATII) cells with an apparent dissociation constant (K(d)) of 4.4 nM and binding maximum (Bmax) 9.8 pmol/mg. Consistent with these results, the D(1) receptor messenger RNA (mRNA) and protein were detected in ATII cells by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. These data demonstrate a novel mechanism involving the activation of dopaminergic D(1) receptors which mediates DA-stimulated edema removal from rat lungs.

Isoproterenol improves ability of lung to clear edema in rats exposed to hyperoxia.

Exposure of adult rats to 100% O(2) results in lung injury and decreases active sodium transport and lung edema clearance. It has been reported that beta-adrenergic agonists increase lung edema clearance in normal rat lungs by upregulating alveolar epithelial Na(+)-K(+)-ATPase function. This study was designed to examine whether isoproterenol (Iso) affects lung edema clearance in rats exposed to 100% O(2) for 64 h. Active Na(+) transport and lung edema clearance decreased by approximately 44% in rats exposed to acute hyperoxia. Iso (10(-6) M) increased the ability of the lung to clear edema in room-air-breathing rats (from 0.50 +/- 0.02 to 0.99 +/- 0. 05 ml/h) and in rats exposed to 100% O(2) (from 0.28 +/- 0.03 to 0. 86 +/- 0.09 ml/h; P < 0.001). Disruption of intracellular microtubular transport of ion-transporting proteins by colchicine (0. 25 mg/100 g body wt) inhibited the stimulatory effects of Iso in hyperoxia-injured rat lungs, whereas the isomer beta-lumicolchicine, which does not affect microtubular transport, did not inhibit active Na(+) transport stimulated by Iso. Accordingly, Iso restored the lung's ability to clear edema after hyperoxic lung injury, probably by stimulation of the recruitment of ion-transporting proteins (Na(+)-K(+)-ATPase) from intracellular pools to the plasma membrane in rat alveolar epithelium.

Ventilator-associated lung injury decreases lung ability to clear edema in rats.

Ventilator-associated lung injury (VALI) is caused by high tidal volume (VT) excursions producing microvascular leakage and pulmonary edema. However, the effects of VALI on lung edema clearance and alveolar epithelial cells' Na,K-ATPase function have not been elucidated. We studied lung edema clearance in the isolated-perfused rat lung model after ventilation for 25, 40, and 60 min with high VT (peak airway opening pressure [Pao] of approximately 35 cm H2O) and compared them with low VT ventilation (Pao approximately 8 cm H2O), moderate VT ventilation (Pao approximately 20 cm H2O), and nonventilated rats. Lung edema clearance in control rats was 0.50 +/- 0.02 ml/h and decreased after 40 and 60 min of high VT to 0.26 +/- 0.03 and 0.11 +/- 0.08 ml/h, respectively (p < 0.01), but did not change after low VT and moderate VT ventilation at any time point. Lung permeability to small (22Na+, [3H]mannitol) and large solutes (fluorescein isothiocyanate-tagged albumin [FITC-albumin]) increased significantly in rats ventilated for 60 min with high VT, compared with low VT, moderate VT, and control rats (p < 0.01). Paralleling the impairment in lung edema clearance we found a decrease in Na,K-ATPase activity in alveolar type II (ATII) cells isolated from rats ventilated with moderate VT and high VT for 40 min without changes in alpha1 Na,K-ATPase mRNA. We reason that VALI decreases lung ability to clear edema by inhibiting active sodium transport and Na,K-ATPase function in the alveolar epithelium.

Dopamine restores lung ability to clear edema in rats exposed to hyperoxia.

Exposure to hyperoxia causes lung injury, decreases active sodium transport and lung edema clearance in rats. Dopamine (DA) increases lung edema clearance by stimulating vectorial Na+ flux and Na, K-ATPase function in rat alveolar epithelium. This study was designed to test whether DA (10(-)5 M) would increase lung edema clearance in rats exposed to 100% O2 for 64 h. Active Na+ transport and lung edema clearance decreased by approximately 44% in rats exposed to acute hyperoxia (p < 0.001). DA increased lung edema clearance in room air breathing rats (from 0.50 +/- 0.02 to 0.75 +/- 0.06 ml/h) and in rats exposed to 100% O2 (from 0.28 +/- 0.03 to 0. 67 +/- 0.03 ml/h). Disruption of cell microtubular transport system by colchicine blocked the stimulatory effect of DA on active Na+ transport in control and hyperoxic rats, whereas the isomer beta-lumicolchicine, which does not affect cell microtubular transport, did not inhibit the stimulatory effects of dopamine. The Na,K-ATPase alpha1-subunit protein abundance increased in the basolateral membranes of alveolar type II (ATII) cells incubated with 10(-)5 M DA for 15 min, probably by recruiting Na+ pumps from intracellular pools. Colchicine, but not beta-lumicolchicine, prevented the recruitment of alpha1 subunits to the plasma membrane by DA. Accordingly, DA restored lung ability to clear edema in hyperoxic-injured rat lungs. Conceivably, dopamine induces recruitment of Na+ pumps from intracellular pools to the plasma membrane of alveolar epithelial cells and thus increases lung edema clearance.

Modulation of lung liquid clearance by isoproterenol in rat lungs.

beta-Adrenergic agonists have been reported to increase lung liquid clearance by stimulating active Na+ transport across the alveolar epithelium. We studied mechanisms by which beta-adrenergic isoproterenol (Iso) increases lung liquid clearance in isolated perfused fluid-filled rat lungs. Iso perfused through the pulmonary circulation at concentrations of 10(-4) to 10(-8) M increased lung liquid clearance compared with that of control lungs (P < 0.01). The increase in lung liquid clearance was inhibited by the beta-antagonist propranolol (10(-5) M), the Na(+)-channel blocker amiloride (10(-4) M), and the antagonist of Na-K-ATPase, ouabain (5 x 10(-4) M). Colchicine, which inhibits cell microtubular transport of ion-transporting proteins to the plasma membrane, blocked the stimulatory effects of Iso on active Na+ transport, whereas the isomer lumicolchicine, which does not affect cell microtubular transport, did not inhibit Na+ transport. In parallel with these changes, the Na-K-ATPase alpha 1-subunit protein abundance and activity increased in alveolar type II cells stimulated by 10(-6) M Iso. Colchicine blocked the stimulatory effect of Iso and the recruitment of Na-K-ATPase alpha 1-protein to the basolateral membrane of alveolar type II cells. Accordingly, Iso increased active Na+ transport and lung liquid clearance by stimulation of beta-adrenergic receptors and probably by upregulation of apical Na+ channels and basolateral Na-K-ATPase mechanisms. Recruitment from intracellular pools and microtubular transport of Na+ pumps to the plasma membrane participate in beta-adrenergic stimulation of lung liquid clearance in rat lungs.

Structure and expression of the human Na,K-ATPase beta 2-subunit gene.

We cloned and characterized the human Na,K-ATPase beta 2-subunit gene. The gene encompasses over 8 kb at chromosome 17 in the human genome and is composed of seven exons. Primer extension analysis identified a major transcription initiation site 529 bases upstream of the translation start site. The 5'-flanking region of the gene harbors a potential TATA sequence, located 94 bases upstream of the transcription initiation site and a number of potential promoter and regulatory elements, among them a Sp1 site, at position -120. A functional Sp1 site has also been found in the rat Na,K-ATPase beta 2-subunit gene (Kawakami, K., Watanabe, Y., Araki, M., Nagano, K., 1993). Sp1 binds to the adhesion molecule on glia regulatory element that functions as a positive transcription regulatory element in astrocytes. (J. Neurosci. Res. 35, 138-146). Putative AATAAA and TG sequences were found at positions 7018 and 7068, respectively. These signals delimit the origin of the the poly(A) tail and mark the end of the sequence that completes the 3'-UT downstream sequence of the human cDNA. An Alu repetitive sequence is located between positions 5961 and 6274. The gene is expressed as a single mRNA species, of 3.36 kb, which is present in cerebrum, cerebellum, kidney and heart, being more abundant in neural tissues. Structural analyses of this and other of the P-type ATPase beta subunit genes reveal that they evolved from a common ancestor.

Expression of the beta 1 and beta 2(AMOG) subunits of the Na,K-ATPase in neural tissues: cellular and developmental distribution patterns.

We have used isoform-specific antisera against the Na,K-ATPase beta 1 (SpETb1) and beta 2(AMOG) (SpETb2) subunit isoforms in order to establish their specific cellular and subcellular localization in several developmental stages of the rat central nervous system. Immunocytochemical preparations revealed beta 1 Isoform protein in most neural cells, being predominantly located in the soma of neurons and astrocytes, with no appreciable developmental variations. In the newborn rat, beta 2(AMOG) immunoreactivity was present in cellular processes of astroglia and in the somas of neurons and decreasing in intensity with maturation until adulthood, where no beta 2 isoform was detected in neurons. The differential location of these isoforms, both developmentally and at the cellular level suggest a complex regulation of their genes expression and mechanisms of subcellular distribution, as well as functional differences.

[Production of specific antibodies against isoforms of the beta subunit of human Na,K-ATPase]. / Generación de anticuerpos específicos contra las isoformas de la subunidad beta de la Na,K-ATPasa humana.

The study of the differential and functional tissular distribution of the isoforms of Na,K-ATPase, an enzyme located on the plasma membrane of animal cells, must be performed with the aid of antibodies capable of specifically recognising beta 1 and beta 2 subunits. In order to facilitate the study of the functions and distribution of such isoforms, proteins were generated using pET series plasmid construction and transformation in E coli bacteria, and their production was promoted with IPTG, these being the antigens that induce antibodies specific for each isoform. The antisera thus obtained were used in Western Blot assays with tissue microsomes from different animal species; specifically, beta 1 and beta 2 isoforms of Na,K-ATPase could be recognised. A panel of polyclonal antibodies was obtained which proved capable of recognising these isoforms in different animal species, as well as their deglycosylated isoform. Such antibodies can be used as an efficient tool for functional and tissue distribution studies of the two isoforms.