A new way to approach ASD children in Dentistry.

AIM: To present an innovative dental approach for children with autism spectrum disorder to the scientific community, along with the 3 questionnaires formulated to evaluate its effectiveness. METHODS: Development of the 3 questionnaires occurred in five stages: observation of the behaviours of ADS children and their caregivers attending the Dental Department in the year 2021; issues detection: anxiety in parents, crying, difficulty in waiting and hyperactivity of the children, fear of both parents and children; formulation of the questionnaires in order to obtain all the information necessary to assess the patient's psychological well-being; validation with submission of the questionnaires to two specialists; modification and final drafting. CONCLUSION: Using the 3 questionnaires, the dentist will be able to assess the wellbeing of the patient and his/her family when attending the dental environment, monitor oral hygiene manoeuvres and verify the usefulness of the orthodontic approach to ADS child while creating a trusting relationship with the patient and his/her caregivers.

Oral surgery in paediatric dentistry: type of surgical treatment and age distribution in a Public Dental Service in Northern Italy.

AIM: To describe the organisation of the oral dental surgery service of the Department of Pediatric Odontostomatology and Orthodontics, "G. Gaslini" Hospital of Genoa (Italy), as well as type and frequency of the interventions carried out in the considered period of time. MATERIALS AND METHODS: Study design: Descriptive retrospective aepidemiological study about the access and surgery interventions in the years 2015-2018 and the first semester of 2019. This study was conducted at the Department of Pediatric Odontostomatology and Orthodontics of the "G. Gaslini" Hospital of Genoa, Italy, in which treatment is offered to children and adolescents aged between 0-14 years, to whom continuity of care is ensured also after this age range, and to special needs patients, even older that 18 years. The clinical data were extracted from the Hospital database and then statistically analysed with the SPSS programme. RESULTS: Out of a total of 27,663 subjects, the patients who required oral surgery were 1,928 corresponding to 6.96%, for a total of 2,499 surgical interventions of which 1,667 were performed as outpatient surgery (dental chair) and 832 in the operating theatre. All the surgeries were performed by the same three doctors. In the group of patients under 18 years (1,773 subjects) the average age is 9.22 years; it should be underscored that over 70% of oral surgeries are performed on subjects between 7 and 13 years. CONCLUSIONS: Given the low frequency of paediatric oral surgery, this type of intervention should be entrusted to operators and structures that have a wider experience in such cases in order to ensure the highest levels ofsafety.

TRPV4 mediates flow-induced increases in intracellular Ca in medullary thick ascending limbs.

UNLABELLED: Medullary thick ascending limbs (mTAL) regulate Na balance and therefore blood pressure. We previously showed that cell swelling and luminal flow activates the mechanosensitive channel TRPV4 in mTAL. AIM: We hypothesized that TRPV4 mediates flow-induced increases in intracellular Ca (Cai) in rat mTALs. METHODS: We performed ratiometric measurements of Cai in perfused mTALs. RESULTS: Increasing luminal flow from 0 to 20 nL min(-1) caused Cai to peak 231 ± 29 nmol L(-1) above basal concentrations (n = 18). The general TRPV inhibitor ruthenium red at 15 and 50 µmol L(-1) reduced peak Cai by 41 ± 9 (P < 0.01; n = 5) and 77 ± 10% (P < 0.02; n = 6). The selective TRPV4 inhibitor RN1734 at 10 and 50 µmol L(-1) reduced peak Cai by 46 ± 11 (P < 0.01; n = 7) and 76 ± 5% (P < 0.02; n = 5) respectively. To specifically target TRPV4, mTALs were transduced with adenoviruses expressing TRPV4 small hairpin (sh) RNA. In non-transduced control mTALs, luminal flow generated a peak increase in Cai of 111 ± 21 nmol L(-1) (n = 8). In TRPV4shRNA-transduced mTALs, the Cai peak was reduced to 56 ± 8 nmol L(-1) (P < 0.03, n = 9). Removing extracellular Ca completely abolished flow-induced increases in Cai. Increasing luminal flow in the presence of hexokinase 20 (U mL(-1) ) to scavenge extracellular ATP did not modify significantly the increases in Cai induced by luminal flow. Finally, we studied the effect of the TRPV4 selective agonist GSK1016790A on Cai. In the absence of luminal flow, GSK1016790A (10 nmol L(-1) ) increased Cai from 60 ± 11 nmol L(-1) to 262 ± 71 nmol L(-1) (P < 0.05; n = 7). CONCLUSION: We conclude that flow-induced increases in Cai are mediated primarily by TRPV4 in the rat mTAL.

Resultados de profilaxis con itraconazol 800 mg/día vía oral en adultos con leucemia aguda y neutropenia de alto riesgo: Hospital del Salvador 2006-2008 / Itraconazole 800 mg for the prophylaxis of fungal infections in patients with acute leukemia and severe neutropenia

Background: Systemic fungal infections and specifically invasive aspergillosis (IA) are associated with a high morbi-mortality rate in patients with hematologic malignancies. Itraconazole kinetic studies show that plasma levels are not satisfactory, even though there is a reduction of the severity in clinical cases. Aim: To evaluate the results of oral prophylaxis with high dose itraconazole, 400 mg bid, among patients with adult acute leukemia. Material and Methods: Prospective analysis of 93 high risk febrile episodes (with an absolute neutrophil count of less than 500 x mm3 for more 10 days), that occurred in 76 patients. Results: Seventy five percent of episodes occurred in patients with acute myeloid leukemia and 25 percent in patients with acute lymphoblastic leukemia. Fifty two percent occurred during the induction of chemotherapy. Median duration of severe neutropenia was 21 days (range 10-48). Median duration of itraconazole prophylaxis was 17 days (range 6-34). A low frequency of invasive fungal infections was observed (17 percent). According to diagnostic criteria, 5 percent of episodes corresponded to persistent fever , 1 percent and 11 percent of episodes, to probable or possible IA, respectively. No confirmed or proven IA was observed. Mortality of IA was 18 percent. No serious adverse events due to itraconazole were observed. Conclusions: The use of high dose itraconazole prophylaxis in adult patients with acute leukemia and severe neutropenia was associated to low incidence and mortality of invasive mycoses.

[Itraconazole 800 mg for the prophylaxis of fungal infections in patients with acute leukemia and severe neutropenia]. / Resultados de profilaxis con itraconazol 800 mg/día vía oral en adultos con leucemia aguda y neutropenia de alto riesgo: Hospital del Salvador 2006-2008.

BACKGROUND: Systemic fungal infections and specifically invasive aspergillosis (IA) are associated with a high morbi-mortality rate in patients with hematologic malignancies. Itraconazole kinetic studies show that plasma levels are not satisfactory, even though there is a reduction of the severity in clinical cases. AIM: To evaluate the results of oral prophylaxis with high dose itraconazole, 400 mg bid, among patients with adult acute leukemia. MATERIAL AND METHODS: Prospective analysis of 93 high risk febrile episodes (with an absolute neutrophil count of less than 500 x mm3 for more 10 days), that occurred in 76 patients. RESULTS: Seventy five percent of episodes occurred in patients with acute myeloid leukemia and 25% in patients with acute lymphoblastic leukemia. Fifty two percent occurred during the induction of chemotherapy. Median duration of severe neutropenia was 21 days (range 10-48). Median duration of itraconazole prophylaxis was 17 days (range 6-34). A low frequency of invasive fungal infections was observed (17%). According to diagnostic criteria, 5% of episodes corresponded to persistent fever , 1% and 11% of episodes, to probable or possible IA, respectively. No confirmed or proven IA was observed. Mortality of IA was 18%. No serious adverse events due to itraconazole were observed. CONCLUSIONS: The use of high dose itraconazole prophylaxis in adult patients with acute leukemia and severe neutropenia was associated to low incidence and mortality of invasive mycoses.

Cancer incidence in pet dogs: findings of the Animal Tumor Registry of Genoa, Italy.

BACKGROUND: The occurrence of spontaneous tumors in pet animals has been estimated in a few European and North American veterinary cancer registries with dissimilar methodologies and variable reference populations. OBJECTIVES: The Animal Tumor Registry (ATR) of Genoa, Italy, was established in 1985 with the aim of estimating the occurrence of spontaneous tumors in dogs. METHODS: Six thousand seven hundred and forty-three tumor biopsy specimens were received from local veterinarians in the Municipality of Genoa between 1985 and 2002. Three thousand and three hundred and three (48.9%) biopsy specimen samples were diagnosed as cancer and were coded according to the International Statistical Classification of Diseases (ICD-9). RESULTS: Mammary cancer was the most frequently diagnosed cancer in female dogs, accounting for 70% of all cancer cases. Incidence of all cancers was 99.3 per 100,000 dog-years (95% CI: 93.6-105.1) in male dogs and 272.1 (95% CI: 260.7-283.6) in female dogs. The highest incidence rates were detected for mammary cancer (IR = 191.8, 95% CI: 182.2-201.4) and for non-Hodgkin's lymphoma (IR = 22.9, 95% CI: 19.7-26.5) in bitches and for non-Hodgkin's lymphoma (IR = 19.9, 95% CI: 17.4-22.7) and skin cancer (IR = 19.1, 95% CI: 16.6-21.8) in male dogs. All cancer IR increased with age ranging between 23.7 (95% CI: 18.4-30.1) and 763.2 (95% CI: 700.4-830.1) in bitches and between 16.5 (95% CI: 12.8-21.1) and 237.6 (95% CI: 209.1-269.0) in male dogs aged < or =3 years and >9-11 years. CONCLUSION: This study summarizes the work done by the ATR of Genoa, Italy, between 1985 and 2002. All cancer incidence was 3 times higher in female than in male dogs, a difference explained by the high rate of mammary cancer observed in bitches. Because a biopsy specimen was required to make a cancer diagnosis, cancer rates for internal organs cancers, such as respiratory and digestive tract cancers may have been underestimated in the study population.

Role of AQP2 in activation of calcium entry by hypotonicity: implications in cell volume regulation.

We previously reported in a rat cortical collecting duct cell line (RCCD(1)) that the presence of aquaporin 2 (AQP2) in the cell membrane is critical for the rapid activation of regulatory volume decrease mechanisms (RVD) (Ford et al. Biol Cell 97: 687-697, 2005). The aim of our present work was to investigate the signaling pathway that links AQP2 to this rapid RVD activation. Since it has been previously described that hypotonic conditions induce intracellular calcium ([Ca(2+)](i)) increases in different cell types, we tested the hypothesis that AQP2 could have a role in activation of calcium entry by hypotonicity and its implication in cell volume regulation. Using a fluorescent probe technique, we studied [Ca(2+)](i) and cell volume changes in response to a hypotonic shock in WT-RCCD(1) (not expressing aquaporins) and in AQP2-RCCD(1) (transfected with AQP2) cells. We found that after a hypotonic shock only AQP2-RCCD(1) cells exhibit a substantial increase in [Ca(2+)](i). This [Ca(2+)](i) increase is strongly dependent on extracellular Ca(2+) and is partially inhibited by thapsigargin (1 muM) indicating that the rise in [Ca(2+)](i) reflects both influx from the extracellular medium and release from intracellular stores. Exposure of AQP2-RCCD(1) cells to 100 muM gadolinium reduced the increase in [Ca(2+)](i) suggesting the involvement of a mechanosensitive calcium channel. Furthermore, exposure of cells to all of the above described conditions impaired rapid RVD. We conclude that the expression of AQP2 in the cell membrane is critical to produce the increase in [Ca(2+)](i) which is necessary to activate RVD in RCCD(1) cells.

Electrical parameters and water permeability properties of monolayers formed by T84 cells cultured on permeable supports.

T84 is an established cell line expressing an enterocyte phenotype whose permeability properties have been widely explored. Osmotic permeability (POSM), hydraulic permeability (PHYDR) and transport-associated net water fluxes (JW-transp), as well as short-circuit current (ISC), transepithelial resistance (RT), and potential difference (deltaVT) were measured in T84 monolayers with the following results: POSM 1.3 +/- 0.1 cm.s-1 x 10-3; PHYDR 0.27 +/- 0.02 cm.s-1; RT 2426 +/- 109 omega.cm2, and deltaVT 1.31 +/- 0.38 mV. The effect of 50 microM 5,6-dichloro-1-ethyl-1,3-dihydro-2H-benzimidazol-2-one (DCEBIO), a "net Cl- secretory agent", on T84 cells was also studied. We confirm the reported important increase in ISC induced by DCEBIO which was associated here with a modest secretory deltaJW-transp. The present results were compared with those reported using the same experimental approach applied to established cell lines originating from intestinal and renal epithelial cells (Caco-2, LLC-PK1 and RCCD-1). No clear association between PHYDR and RT could be demonstrated and high PHYDR values were observed in an electrically tight epithelium, supporting the view that a "water leaky" barrier is not necessarily an "electrically leaky" one. Furthermore, the modest secretory deltaJW-transp was not consistent with previous results obtained with RCCD-1 cells stimulated with vasopressin (absorptive fluxes) or with T84 cells secreting water under the action of Escherichia coli heat stable enterotoxin. We conclude that, while the presence of aquaporins is necessary to dissipate an external osmotic gradient, coupling between water and ion transport cannot be explained by a simple and common underlying mechanism.

Electrical parameters and water permeability properties of monolayers formed by T84 cells cultured on permeable supports

T84 is an established cell line expressing an enterocyte phenotype whose permeability properties have been widely explored. Osmotic permeability (P OSM), hydraulic permeability (P HYDR) and transport-associated net water fluxes (J W-transp), as well as short-circuit current (I SC), transepithelial resistance (R T), and potential difference (deltaV T) were measured in T84 monolayers with the following results: P OSM 1.3 ± 0.1 cm.s-1 x 10-3; P HYDR 0.27 ± 0.02 cm.s-1; R T 2426 ± 109 omega.cm², and deltaV T 1.31 ± 0.38 mV. The effect of 50 æM 5,6-dichloro-1-ethyl-1,3-dihydro-2H-benzimidazol-2-one (DCEBIO), a "net Cl- secretory agent", on T84 cells was also studied. We confirm the reported important increase in I SC induced by DCEBIO which was associated here with a modest secretory deltaJ W-transp. The present results were compared with those reported using the same experimental approach applied to established cell lines originating from intestinal and renal epithelial cells (Caco-2, LLC-PK1 and RCCD-1). No clear association between P HYDR and R T could be demonstrated and high P HYDR values were observed in an electrically tight epithelium, supporting the view that a "water leaky" barrier is not necessarily an "electrically leaky" one. Furthermore, the modest secretory deltaJ W-transp was not consistent with previous results obtained with RCCD-1 cells stimulated with vasopressin (absorptive fluxes) or with T84 cells secreting water under the action of Escherichia coli heat stable enterotoxin. We conclude that, while the presence of aquaporins is necessary to dissipate an external osmotic gradient, coupling between water and ion transport cannot be explained by a simple and common underlying mechanism.

Asymmetry in the osmotic response of a rat cortical collecting duct cell line: role of aquaporin-2.

Transition from antidiuresis to diuresis exposes cortical collecting duct cells (CCD) to asymmetrical changes in environment osmolality, inducing an osmotic stress, which activates numerous membrane-associated events. The aim of the present work was to investigate, either in the presence or not of AQP2, the transepithelial osmotic water permeability (P(osm)) following cell exposure to asymmetrical hyper- or hypotonic gradients. For this purpose, transepithelial net volume fluxes were recorded every minute in two CCD cell lines: one not expressing AQPs (WT-RCCD(1)) and another stably transfected with AQP2 (AQP2-RCCD(1)). Our results demonstrated that the rate of osmosis produced by a given hypotonic shock depends on the gradient direction (osmotic rectification) only in the presence of apical AQP2. In contrast, hypertonic shocks elicit P(osm) rectification independently of AQP2 expression, and this phenomenon may be linked to modulation of basolateral membrane permeability. No asymmetry in transepithelial resistance was observed under hypo- or hypertonicity, indicating that rectification cannot be attributed to a shunt through the tight junction path. We conclude that osmotic rectification may be explained in terms of dynamical changes in membrane permeability probably due to activation/incorporation of AQPs or transporters to the plasma membrane via some mechanism triggered by osmolality.

Differential role of Na+/H+ exchange isoforms NHE-1 and NHE-2 in a rat cortical collecting duct cell line.

The Na+/H+ exchanger (NHE) constitutes a gene family containing several isoforms that display different membrane localization and are involved in specialized functions. Although basolateral NHE-1 activity was described in the cortical collecting duct (CCD), the localization and function of other NHE isoforms is not yet clear, This study examines the expression, localization, and regulation of NHE isoforms in a rat cortical collecting duct cell line (RCCD1) that has previously been shown to be a good model of CCD cells. Present studies demonstrate the presence of NHE-1 and NHE-2 isoforms, but not NHE-3 and NHE-4, in RCCD1 cells. Cell monolayers, grown on permeable filters, were placed on special holders allowing independent access to apical and basolateral compartments. Intracellular pH (pHi) regulation was spectrofluorometrically studied in basal conditions and after stimulation by NH4Cl acid load or by a hyperosmotic shock. In order to differentiate the roles of NHE-1 and NHE-2, we have used HOE-694, an inhibitor more selective for NHE-1 than for NHE-2. The results obtained strongly suggest that NHE-1 and NHE-2 are expressed in the basolateral membrane but that they have different roles: NHE-1 is responsible for pHi recovery after an acid load and NHE-2 is mainly involved in steady-state pHi and cell volume regulation.

Bone allografts and adjuvant cisplatin for the treatment of canine appendicular osteosarcoma in 18 dogs.

The results achieved in 18 dogs following the use of frozen bone cortical allografts for limb-sparing resection of non-metastatic canine appendicular osteosarcoma are presented. Three to five cisplatin doses (70 mg/m2) were administered, starting the day after surgery. The mean and median survival times were 478 and 266 days (range 80 to 2,611 days), respectively. The survival rate was 94 per cent at three months, 78 per cent at six months, 35 per cent at 12 months, 23 per cent at 18 months and 19 per cent at 24 months; the disease-free interval was 80 to 1,246 days (mean 365 days, median 266 days). Lung metastasis developed in 55 per cent of the dogs within one year. Complications were observed in 14/18 dogs (78 per cent), comprising local recurrence (28 per cent), allograft infection (39 per cent) and implant failure (11 per cent). Despite complications, limb sparing is a useful alternative to amputation in selected cases of appendicular osteosarcoma.

Vasopressin regulates water flow in a rat cortical collecting duct cell line not containing known aquaporins.

Transepithelial water movements and arginine-vasopressin (AVP)-associated ones were studied in a renal cell line established from a rat cortical collecting duct (RCCD(1)). Transepithelial net water fluxes (J(w)) were recorded every minute in RCCD(1) monolayers cultured on permeable supports. Spontaneous net water secretion was observed, which was inhibited by serosal bumetanide (10(-5) m), apical glibenclamide (10(-4) m) and apical BaCl(2) (5 x 10(-3) m). RT-PCR, RNAse protection and/or immunoblotting experiments demonstrated that known renal aquaporins (AQP1, AQP2, AQP3, AQP4, AQP6 and AQP7) were not expressed in RCCD(1) cells. AVP stimulates cAMP production and sodium reabsorption in RCCD(1) cells. We have now observed that AVP significantly reduces the spontaneous water secretory flux. The amiloride-sensitive AVP-induced increase in short-circuit current (I(sc)) was paralleled by a simultaneous modification of the observed J(w): both responses had similar time courses and half-times (about 4 min). On the other hand, AVP did not modify the osmotically driven J(w) induced by serosal hypertonicity. We can conclude that: (i) transepithelial J(w) occurs in RCCD(1) cells in the absence of known renal aquaporins; (ii) the "water secretory component" observed could be linked to Cl- and K = secretion; (iii) the natriferic response to AVP, preserved in RCCD(1) cells, was associated with a change in net water flux, which was even observed in absence of AQP2, AQP3 or AQP4 and (iv) the hydro-osmotic response to AVP was completely lost.

Estudio de viabilidad de escólices de quistes hidatídicos hepáticos humanos / Viability study of scolices of human hydatid liver cysts

El adecuado control de la hidatidosis en general, requiere conocer algunos aspectos relacionados con la supervivencia de los agentes infectantes, especialmente de los escólices. El objetivo de este trabajo, es evaluar la viabilidad de los escólices de quistes hidatídicos humanos de localización hepática. Estudiar la asociación entre las características clínicas al momento de la cirugía y el porcentaje de viabilidad de los escólices. Los criterios de viabilidad utilizados fueron: forma ovoide, invaginados, ganchos rostrales y corpúsculos calcáreos intactos, movimientos vibratorios presentes y ausencia de tinción con colorantes vitales. Los criterios para certificar mortalidad de los escólices fueron dos o más de los siguientes hechos: inmovilidad, alteración de los ganchos rostrales y de los corpúsculos calcáreos, rotura de membrana y pérdida de la forma ovoide y fácil tinción con el colorante vital (azul de tripan al 1,5 por ciento). Se estudiaron de esta forma 16 quistes, con un diámetro promedio de 16,2 cm. Siete lesiones (44 por ciento) de tipo univesicular, 5 (31 por ciento) multivesiculares y 4 (25 por ciento) quistes abscedados. En 7 oportunidades (44 por ciento), se evidenció comunicación a la vía biliar; y se constató viabilidad en 9 de los 16 quistes (56 por ciento). Las muestras con mayor porcentaje de escólices viables fueron los quistes multivesiculares, principalmente a expensas de las vesículas hijas. Se constató que los quistes multivesiculares eran viables en el 100 por ciento de los casos, a diferencia de los univesiculares con un 57 pir ciento y los abscedados con 0 por ciento (p= 0,01)

Effects of medium hypertonicity on water permeability in the mammalian rectum: ultrastructural and molecular correlates.

Minute-by-minute net water fluxes (Jw) were measured across the isolated rectal epithelium in rats and rabbits. Five minutes after a serosal (but not mucosal) hypertonic challenge (plus 200 mosmol/l) a significant increase in the basal Jw was recorded in both species [deltaJw, microl min(-1) cm(-2): 0.40+/-0.06 (rats); 0.45+/-0.10 (rabbits)]. At the same time, most epithelial cells shrank markedly while the intercellular spaces were wide open (electron microscopy studies). In freeze-fracture studies multi-strand tight-junction structures (only slightly modified by serosal hypertonicity in rabbits) were observed in control conditions. No structural changes were observed after mucosal hypertonicity (both in rats and rabbits). Immunohistochemical studies showed the expression of aquaporin 3 (AQP3) at the basolateral membrane of epithelial cells in the rat. A first conclusion is that the epithelium of the mammalian rectum is a highly polarized, aquaporin-3-containing, water permeability structure. The Jw increase induced by serosal hypertonicity was sensitive to mercurial agents in both species and no changes in unidirectional [14C]mannitol fluxes (Ps) or transepithelial resistance (RT) were observed during this Jw increase. These observations suggest a transcellular route for the osmotically induced increase in water fluxes. In the rabbit rectum the initial Jw response, associated with serosal hypertonicity, was a transient one. It was followed by a second, slow and HgCl2-sensitive Jw increase (a transient peak in paracellular mannitol permeability was also observed). A second conclusion is that serosal hypertonicity induces an increase in transcellular water permeability in both rat and rabbit rectum.

Water permeability in rat oocytes at different maturity stages: aquaporin-9 expression.

Important functional and structural modifications occur in mammalian oocytes during their arrival to maturity. In this process, oocytes switch from a high activity level, implying an important metabolic rate and a coordinated movement of water and solutes, to a lower functional state. The aim of this work was to study the mechanisms involved in water movements during oocyte arrival to maturity. Volume changes, induced by an osmotic gradient, were followed by video microscopy in rat oocytes. The water osmotic permeability (P(osm)) of immature oocytes (proestrus) was sensitive to HgCl(2) and phloretin. In contrast, mature oocytes (estrus) had a reduced P(osm) that was not sensitive to these compounds. When proestrus oocytes were incubated in vitro at 37 degrees C they spontaneously arrived at maturity and its P(osm) decreased between four and six hours of incubation. RT-PCR experiments were performed using specific primers for all rat aquaporins that had been cloned. We found that aquaporin-9 transcript (AQP9) is present in proestrus oocytes but not in estrus oocytes. AQP9 has been recently described as a "broad selective channel" responsible for solute and water transfers in highly active cells. Our experiments showed that proestrus oocytes, but not estrus, are permeable to mannitol. It is concluded that during the process of maturation, P(osm) decreases and AQP9 transcripts disappear. We report here the first study correlating water permeability and aquaporin mRNA expression in mammalian oocytes.

Estudio de asociación entre magnitud de la hipotonía esfinteriana y transtorno motor del cuerpo esofágico / Association between lower esophageal sphincter resting pressure and esophageal motor disorders

Background: One of the most important factors involved in the pathophysiology of gastroesophageal reflux disease (GERD) is the lower esophageal sphincter rest pressure (LESRP), but these patients can have esophageal motor disorders (EMD). Aim: To assess an association between LESRP and the appearance of EMD in patients with GERD. Subjects and methods: A cross-sectional study was conducted in 229 patients with GERD and 49 healthy controls. Forty five patients with LESRP < 6 mmHg and a mean age of 49 years were assigned to group 1, 128 patients with a LESRP between 6 and 12 mmHg and mean age of 47 years were assigned to group 2, 56 patients with a a LESRP >12 mmHg and a mean age of 47 years were assigned to group 3 and group 4 was conformed by 49 healthy subjects aged 40 years old. Esophageal manometry was performed using previously published techniques. Results: There was a significant association between LESRP, waves amplitude and the frequency of tertiary waves. Conclusions: Resting lower esophageal sphincter pressure is inversely proportional to the presence of esophageal motor disorders in patients with gastroesophageal reflux disease

Transcriptional regulation of sodium transport by vasopressin in renal cells.

We have examined whether arginine vasopressin (AVP) can induce a long-term modulation of transepithelial ion transport in addition to its well known short-term effect. In the RCCD1 rat cortical collecting duct cell line, an increase in both short-circuit current and 22Na transport was observed after several hours of 10(-8) M AVP treatment (a concentration above the in vivo physiological range). This delayed effect was partially prevented by apical addition of 10(-5) M amiloride and was blocked by 10(-6) M actinomycin D and 2 x 10(-6) M cycloheximide. The amounts of mRNA encoding the alpha1 (not beta1) subunit of Na+/K+-ATPase and the beta and gamma (not alpha) subunits of the amiloride-sensitive epithelial Na+ channel were significantly increased by AVP treatment. The increase in mRNA was blocked by actinomycin D, not by amiloride, suggesting a Na+-independent increase in the rate of transcription of these subunits. The translation rates of the alpha1 subunit of Na+/K+-ATPase and the beta and gamma subunits of the rat epithelial sodium channel increased significantly, whereas the translation rates of the other subunits remained unchanged. Finally, the number of Na+ channels present in the apical membrane of the cells increased, as demonstrated by enhanced specific [3H]phenamil binding.

Biophysical properties of epithelial water channels.

The biophysical models describing the structure of water pores or channels have evolved, during the last forty years, from a pure 'black box' approach to a molecular based proposal. The initial 'sieving pore' in which water and other molecules were moving together was replaced by a more restrictive model, where water is moving alone in a 'single file' mode. Aquaporins discovery and cloning [G.M. Preston, T.P. Carroll, W.B. Guggino, P. Agre, Science 256 (1992) 365] leaded to the 'hour-glass model' and other alternative proposals, combining information coming from molecular biology experiments and two dimensional crystallography. Concerning water transfers in epithelial barriers the problem is quite complex, because there are at least two alternative pathways: paracellular and transcellular and three different driving forces: hydrostatic pressure, osmotic pressure or 'transport coupled' movements. In the case of ADH-sensitive epithelia it is more or less accepted that regulated water channels (AQP2), that can be inserted in the apical membrane, coexist with basolateral resident water channels (AQP3). The mechanism underlying the so-called 'transport associated water transfer' is still controversial. From the classical standing gradient model to the ion-water co-transport, different hypothesis are under consideration. Coming back to hormonal regulations, other than the well-known regulation by neuro-hypophysis peptides, a steroid second messenger, progesterone, has been recently proposed [P. Ford, G. Amodeo, C. Capurro, C. Ibarra, R. Dorr, P. Ripoche, M. Parisi, Am. J. Physiol. 270 (1996) F880].