RESUMO
Groundwater in karst aquifers is frequently tapped for drinking purposes, due to frequent huge volumes of resources. Unfortunately, vulnerability of these aquifers can be high, due to possible fast transfer of recharge water on springs by the karst network. On Gran Sasso Mountain regional aquifer, several springs are subjected to drinking withdrawal and an updated evaluation of their potential is now a fundamental issue to be considered, facing climate change effects, which reflect on variation of discharge regimen and values. To distinguish between different contribution of spring recharge, a tracer test has been carried out on the Vitella d'Oro spring, fed both by the regional aquifer and by a local system exposed to karst features developed in the Rigopiano Conglomerates formation. Thanks to hydrogeological, hydrogeochemical and isotopic data, a conceptual model of spring recharge has been proposed and subsequently validated by the tracer test results. All information confirms the superimposition on the regional base flow, by a relevant contribution of the karst network, influencing the spring discharge in recharge periods. In detail, a fast flow component is responsible for discharge peaks and frequently of turbidity events, having a mean velocity ranging from 30 to 70 m/h in the aquifer. Besides of this fast flow, an additional aliquot of the recharge is due to the same local aquifer, but slower flow clearly identifiable by hydrochemistry and isotopic data. Thanks to these findings, a renewed management of the spring has been suggested, considering the different degrees of aquifer vulnerability (turbidity occurrence) directly related to the discharge regimen.
RESUMO
Contaminants that are highly soluble in groundwater are rapidly transported via fractures in mechanically resistant sedimentary rock aquifers. Hence, a rigorous methodology is needed to estimate groundwater flow velocities in such fractured aquifers. Here, we propose an approach using borehole hydraulic testing to compute flow velocities in an un-faulted area of a fractured carbonate aquifer by applying the cubic law to a parallel plate model. The Cadeby Formation (Yorkshire, NE England) - a Permian dolostone aquifer present beneath the University of Leeds Farm - is the fractured aquifer selected for this hydraulic experiment. The bedding plane fractures of this dolostone aquifer, which are sub-horizontal, sub-parallel and laterally persistent, largely dominate the flow at shallow (<~40 mBGL) depths. These flowing bedding plane discontinuities are separated by a rock matrix which is relatively impermeable (Kwell-test/Kcore-plug~104) as is common in fractured carbonate aquifers. In the workflow reported here, the number of flowing fractures - mainly bedding plane fractures - intersecting three open monitoring wells are found from temperature/fluid conductivity and acoustic/optical televiewer logging. Following well installation, average fracture hydraulic apertures for screened intervals are found from analysis of slug tests. For the case study aquifer, this workflow predicts hydraulic apertures ranging from 0.10 up to 0.54â¯mm. However, groundwater flow velocities range within two order of magnitude from 13 up to 242â¯m/day. Notably, fracture apertures and flow velocities rapidly reduce with increasing depth below the water table; the upper ~10â¯m shows relatively high values of hydraulic conductivity (0.30-2.85â¯m/day) and corresponding flow velocity (33-242â¯m/day). Permeability development around the water table in carbonate aquifer-types is common, and arises where high pCO2 recharge water from the soil zone causes calcite/dolomite dissolution. Hence, agricultural contaminants entering the aquifer with recharge water are laterally transported rapidly within this upper part. Computation of groundwater flow velocities allows determination of the Reynolds number. Values of up ~1, indicating the lower limit of the transition from laminar to turbulent flow, are found at the studied site, which is situated away from major fault traces. Hence, turbulent flow is likely to arise in proximity to tectonic structures, such as normal faults, which localize flow and enhance karstification. The occurrence of turbulent flow in correspondence of such tectonic structures should be represented in regional groundwater flow simulations.
Assuntos
Água Subterrânea , Movimentos da Água , Carbonatos , Inglaterra , Poços de ÁguaRESUMO
To elucidate the mechanism responsible for the bile acid-induced changes of biliary lipid secretion, we evaluated bile flow and biliary output of bile acids, cholesterol, phospholipids, and alkaline phosphatase activity in seven cholecystectomized subjects with a balloon occludable T-tube during two experimental periods: (a) depletion of the endogenous bile acid pool and (b) replacement of the pool by means of duodenal infusion with individual bile acids, such as deoxycholic (DCA), chenodeoxycholic (CDCA), cholic (CA), and ursodeoxycholic (UDCA) acids. Bile flow, cholesterol, and phospholipid output were linearly related to bile acid secretion in all experimental periods. During the replacement periods, the amount of cholesterol and phospholipids coupled to bile acids was significantly different (at 1% level at least) for each individual bile acid secreted; it was the highest during DCA secretion (slope value: 0.209 for cholesterol and 0.434 for phospholipids) followed, in the order, by CDCA (0.078 and 1.794), CA (0.044 and 0.127), and UDCA (0.030 and 0.122). The phospholipid to cholesterol ratio was higher during secretion of CA and UDCA as compared with DCA and CDCA. The secretion of CA seemed to stimulate a greater bile flow than the other bile acids did. The infusion of all bile acids, except UDCA, induced an increase of biliary alkaline phosphatase activity as compared with the values of the depletion period. The mean highest increase (13-fold the pretreatment value) was observed during DCA secretion followed by CDCA (fivefold) and CA (1.5-fold). These results would suggest that the physical chemical properties, namely the lipid-solubilizing capacity, of bile acids could directly contribute to the regulation of biliary lipid secretion. The observed changes in biliary alkaline phosphatase activity lend support to the view that bile acid-induced lipid secretion may be, at least in part, contributed by membrane solubilization.
Assuntos
Ácidos e Sais Biliares/metabolismo , Bile/metabolismo , Colesterol/metabolismo , Fosfolipídeos/metabolismo , Idoso , Ácidos e Sais Biliares/administração & dosagem , Colecistectomia , Colelitíase/metabolismo , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-IdadeRESUMO
Sandstone aquifers are commonly assumed to represent porous media characterized by a permeable matrix. However, such aquifers may be heavy fractured when rock properties and timing of deformation favour brittle failure and crack opening. In many aquifer types, fractures associated with faults, bedding planes and stratabound joints represent preferential pathways for fluids and contaminants. In this paper, well test and outcrop-scale studies reveal how strongly lithified siliciclastic rocks may be entirely dominated by fracture flow at shallow depths (≤180m), similar to limestone and crystalline aquifers. However, sedimentary heterogeneities can primarily control fluid flow where fracture apertures are reduced by overburden pressures or mineral infills at greater depths. The Triassic St Bees Sandstone Formation (UK) of the East Irish Sea Basin represents an optimum example for study of the influence of both sedimentary and tectonic aquifer heterogeneities in a strongly lithified sandstone aquifer-type. This fluvial sedimentary succession accumulated in rapidly subsiding basins, which typically favours preservation of complete depositional cycles including fine grained layers (mudstone and silty sandstone) interbedded in sandstone fluvial channels. Additionally, vertical joints in the St Bees Sandstone Formation form a pervasive stratabound system whereby joints terminate at bedding discontinuities. Additionally, normal faults are present through the succession showing particular development of open-fractures. Here, the shallow aquifer (depth≤180m) was characterized using hydro-geophysics. Fluid temperature, conductivity and flow-velocity logs record inflows and outflows from normal faults, as well as from pervasive bed-parallel fractures. Quantitative flow logging analyses in boreholes that cut fault planes indicate that zones of fault-related open fractures characterize ~50% of water flow. The remaining flow component is dominated by bed-parallel fractures. However, such sub-horizontal fissures become the principal flow conduits in wells that penetrate the exterior parts of fault damage zones, as well as in non-faulted areas. The findings of this study have been compared with those of an earlier investigation of the deeper St Bees Sandstone aquifer (180 to 400m subsurface depth) undertaken as part of an investigation for a proposed nuclear waste repository. The deeper aquifer is characterized by significantly lower transmissivities. High overburden pressure and the presence of mineral infillings, have reduced the relative impact of tectonic heterogeneities on transmissivity here, thereby allowing matrix flow in the deeper part of the aquifer. The St Bees Sandstone aquifer contrasts the hydraulic behaviour of low-mechanically resistant sandstone rock-types. In fact, the UK Triassic Sandstone of the Cheshire Basin is low-mechanically resistant and flow is supported both by matrix and fracture. Additionally, faults in such weak-rocks are dominated by granulation seams representing flow-barriers which strongly compartmentalize the UK Triassic Sandstone in the Cheshire Basin.
Assuntos
Água Subterrânea , Hidrologia/métodos , Sedimentos Geológicos , Água Subterrânea/química , Minerais , Temperatura , Reino Unido , Movimentos da Água , Poços de ÁguaRESUMO
OBJECTIVE: To establish the accuracy of bioelectrical impedance analysis (BIA) for the assessment of total and appendicular body composition in peritoneal dialysis (PD) patients. DESIGN: Cross-sectional study. SETTING: University Nephrology Clinic. SUBJECTS: In all, 20 PD patients and 77 healthy controls matched for gender, age and body mass index. METHODS: Whole-body fat-free mass (FFM) and appendicular lean tissue mass (LTM) were measured by dual-energy X-ray absorptiometry. Resistance (R) of arms, trunk and legs was measured by eight-polar BIA at frequencies of 5, 50, 250 and 500 kHz. Whole-body resistance was calculated as the sum of R of arms, trunk and legs. The resistance index (RI) was calculated as the ratio between squared height and whole-body or segmental R. RESULTS: RI at 500 kHz was the best predictor of FFM, LTM(arm) and LTM(leg) in both PD patients and controls. Equations developed on controls overestimated FFM and LTM(arm) and underestimated LTM(leg) when applied to PD patients. Specific equations were thus developed for PD patients. Using these equations, the percent root mean-squared errors of the estimate for PD patients vs controls were 5 vs 6% for FFM, 8 vs 8% for LTM(arm) and 7 vs 8% for LTM(leg). CONCLUSION: Eight-polar BIA offers accurate estimates of total and appendicular body composition in PD patients, provided that population-specific equations are used.
Assuntos
Composição Corporal/fisiologia , Impedância Elétrica , Falência Renal Crônica/metabolismo , Diálise Peritoneal , Tecido Adiposo/metabolismo , Braço/anatomia & histologia , Braço/fisiologia , Calibragem , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Perna (Membro)/anatomia & histologia , Perna (Membro)/fisiologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The prevalence of antibodies to HCV and the course of hepatitis have been determined in 357 haemodialysed patients treated at a single institution. The prevalence of HCV infection increases with the duration of haemodialysis and with the use of blood transfusions, yet there is high frequency of HCV seropositivity even without blood transfusions. Evolution of HCV hepatitis to chronicity is frequent and biological signs of chronic hepatopathy can coexist with absence of alanine aminotransferase (ALT) abnormalities.
Assuntos
Hepacivirus/imunologia , Anticorpos Anti-Hepatite/sangue , Diálise Renal/efeitos adversos , Idoso , Alanina Transaminase/sangue , Doença Crônica , Humanos , Itália/epidemiologia , Fígado/patologia , Pessoa de Meia-Idade , Fatores de Risco , Fatores de Tempo , Reação TransfusionalRESUMO
Seminal plasma (n = 12) from cystic fibrosis (CF) patients were analyzed by gel-electrophoresis using seminal plasma and expressed prostatic secretion from fertile men as controls. Heavy precipitation at the entering position of the gel and streaking in the gel matrix was observed, demonstrating a reduced solubility of seminal proteins in CF. Comparison of the protein patterns evidenced that CF-seminal plasma (CF-SP) mainly consisted of prostatic components. Although lactoferrin was undetectable in all samples, trace amounts of low molecular weight proteins were observed in two patients. This latter finding could imply that CF-SP may contain proteolytic fragments of prostatic and/or vesicular proteins or de novo synthesized components.
Assuntos
Antineoplásicos/análise , Fibrose Cística/metabolismo , Proteínas Secretadas pela Próstata , Proteínas/análise , Adolescente , Adulto , Antineoplásicos/metabolismo , Eletroforese em Gel de Poliacrilamida , Humanos , Masculino , Proteínas/metabolismo , Proteínas de Plasma SeminalRESUMO
OBJECTIVE: Striking evidence of HCV infection has been found in mixed cryoglobulinemia (MC) and HCV has been hypothesized to be the causative agent of this disease. To assess the association of C virus infection and cryoglobulinemia we studied cryoglobulin levels in 66 patients on maintenance hemodyalisis who were selected on the basis of HCVAb positivity and not because they were affected by liver disease. The control group was made up of 45 patients also on hemodyalisis but without HCV infection. RESULTS: Circulating cryoglobulins were found in 34 (52%) of 66 HCV+ patients: the cryocrit was < 1% in 20, 1 to 5% in 12, and > 5% in 2 patients. The cryoglobulins were classified by immunofixation as type II in 8 and type III in 8 others; identification was not possible in 18 cases. In the HCVAb- control group untypable cryoglobulins were detected in 9% of the patients at < 1% by volume. No correlation was found between these data and the liver disease detected by biohumoral tests. CONCLUSIONS: Our data confirm the close link between HCV infection and cryoglobulins; the prevalence of circulating cryoglobulins in uremic HCVAb+ patients is very close to that found in HCV-related liver disease.
Assuntos
Crioglobulinemia/virologia , Anticorpos Anti-Hepatite C/análise , Hepatite C/complicações , Diálise Renal , Idoso , Crioglobulinemia/complicações , Crioglobulinas/análise , Feminino , Humanos , MasculinoRESUMO
Preliminary experience on total quality program in access surgery for dialysis is described; this kind of "border-line" surgery requires peculiar standards, documents and quality indexes. The use of a quality index based on a minimum success rate of 90% in elective access surgery is proposed. In addition, a "cross-index", suitable for quality evaluation of different dialysis sectors at the same time, is expressed. First interventions aimed at the optimal use of resources are described.
Assuntos
Cateteres de Demora/normas , Garantia da Qualidade dos Cuidados de Saúde/organização & administração , Diálise Renal/métodos , Procedimentos Cirúrgicos Eletivos , Indicadores Básicos de Saúde , Departamentos Hospitalares/normas , Humanos , Itália , Falência Renal Crônica/terapia , Prontuários Médicos , Garantia da Qualidade dos Cuidados de Saúde/economia , Controle de Qualidade , Diálise Renal/instrumentaçãoRESUMO
Haemodialysis therapy in the elderly has become a recognized reality only in the last decade Information collected from restricted statistics often leads to conflicting conclusions. Length of survival may be a useful indicator of the appropriateness of initiating treatment. Survival and important determinants of survival, such as cardiovascular problems, nutritional status and adequacy of dialysis, are addressed in this study and evaluated in 365 elderly patients, treated at a single institution over a 20 year period.
Assuntos
Diálise Renal , Idoso , Causas de Morte , Humanos , Estado Nutricional , Diálise Renal/mortalidade , Taxa de SobrevidaRESUMO
Clinical rotations in acute medical and psychiatric inpatient facilities are an essential component of the education for undergraduate nursing students. The benefits students receive from these clinical experiences have been documented, but no data have been reported regarding the advantages that students may bring to agencies. This exploratory study, which used a mail-back survey, asked adult health/medical-surgical nurses and mental health/psychiatric nurses in acute care units about the effects undergraduate nursing students had on staff time, staff development, quality of care, staff's personal satisfaction, and unit standards and practices during their clinical rotations. Results indicated that students contribute to the personal and professional satisfaction of the staff by offering opportunities for mentoring and reciprocal learning and allowing nurses to participate in students' professional development. Students also contribute to patient care.
Assuntos
Atitude , Educação em Enfermagem , Recursos Humanos de Enfermagem Hospitalar , Preceptoria , Adulto , Departamentos Hospitalares , Humanos , Avaliação de Programas e Projetos de Saúde , Estados UnidosRESUMO
Human peritoneal fluid has been claimed to influence sperm motility. This report gives evidence for the presence in midcycle peritoneal fluid of a protein-bound, lipidic (hydrophobic) component able to immobilize spermatozoa as a function of time. This component was extracted from molecular weight-sieving and ion-exchange/high pressure liquid chromatography (HPLC)-purified peritoneal fluid fractions by either chloroform/methanol or charcoal treatments; resuspension of the chloroform/methanol extract with BWW-buffer and subsequent testing on spermatozoa resulted in sperm immobilization. Sequential or step-down chromatographic procedures (molecular weight-sieving-->cation-exchange-->anion-exchange HPLC separations of native peritoneal fluid) and extensive dialysis against double distilled water allowed the purification of the sperm immobilizing factor, as evidenced by the shorter incubation times necessary for sperm immobilization. Furthermore, the active fraction was found to immobilize spermatozoa without affecting its viability. Separation of the chloroform/methanol extracted immobilizing fraction on thin layer chromatography under conditions for phospholipid detection allowed the identification of a characteristic band which, after re-extraction, was found to be the sperm immobilizing substance. This factor does not contain choline, ethanolamine or serine. These results suggest that some lipidic peritoneal fluid components may influence sperm motility.
Assuntos
Líquido Ascítico/química , Lipídeos/farmacologia , Motilidade dos Espermatozoides/efeitos dos fármacos , Hidroxitolueno Butilado/farmacologia , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Humanos , Focalização Isoelétrica , Lipídeos/química , Lipídeos/isolamento & purificação , Masculino , Peso MolecularRESUMO
Chemical characterization of seminal vesicle secretion through seminal vesicle proteins would have the following advantages: (1) to judge on the secretory competence of the gland, (2) to recognize atypical secretory patterns, (3) to identify specific molecules and their epitopes for anatomical, diagnostic, therapeutic, anti-fertility and forensic purposes, and (4) to study physiologically active proteins or peptides of seminal plasma. There are different approaches for collection of the specific samples, each of which has peculiar advantages and disadvantages: ejaculate collection in the presence of protease inhibitors, use of split or multi-split ejaculates, utilization of autopsy or surgical material. Liquefied proteins are submitted to different chromatographic and electrophoretic procedures. One must keep in mind, however, that a whole series of biochemical processes can rapidly and irreversibly alter in vivo and in vitro the secretory proteins. The study of the secretion from male accessory sex glands and their interaction with spermatozoa therefore still deserves an absolute research priority.
Assuntos
Técnicas de Química Analítica , Química Clínica , Glândulas Seminais/metabolismo , Humanos , Masculino , Proteínas/análise , Sêmen/químicaRESUMO
A case report is presented of an axillary plexus blockade following a second toe-to-hand transfer. After completion of the microvascular anastomoses and restoration of blood flow to the transplanted toe, the axillary plexus blockade was started. Together with the vasodilation of the hand and forearm there was a marked drop in blood flow in the transplanted toe. Possible explanations for this phenomenon are considered. We suggest starting axillary plexus blockade before completion of microvascular anastomoses and maintaining a continuous postoperative blockade.
Assuntos
Plexo Braquial , Dedos/irrigação sanguínea , Bloqueio Nervoso , Pele/irrigação sanguínea , Adolescente , Anastomose Cirúrgica , Dedos/cirurgia , Humanos , Masculino , Microcirurgia , Fluxo Sanguíneo Regional , Dedos do Pé/irrigação sanguínea , Dedos do Pé/transplante , Procedimentos Cirúrgicos VascularesRESUMO
To further clarify the relationship between physical-chemical characteristics of bile acids and biliary lipid secretion, we investigated the effect of ursocholic acid, the 7 beta-hydroxyepimer of cholic acid, on bile lipid secretion and composition. The study included acute duodenal infusion (1 g/h for 5 h) of ursocholic acid contrasted with a less hydrophilic bile acid, ursodeoxycholic acid, in 3 T-tube patients and short-term oral administration (2 wk) of ursocholic acid (10-15 mg/kg X day) to 10 gallstone patients. Following acute infusion, ursocholic acid, similarly to ursodeoxycholic acid, accounted for greater than 80% of the biliary bile acids. However, ursocholic acid induced (per micromole of secreted bile acid) a significantly lower (p less than 0.01) secretion of cholesterol (0.013 mumol) and phospholipids (0.054 mumol) than that induced by ursodeoxycholic acid (0.034 mumol of cholesterol and 0.138 mumol of phospholipids). Biliary alkaline phosphatase activity during ursocholic acid administration was significantly lower (p less than 0.01) than during ursodeoxycholic acid administration. After short-term oral administration, ursocholic acid, undetectable before treatment, constituted 20.50% +/- 8.60% of the biliary bile acids. The percentage of deoxycholic acid increased from 32.35% +/- 18.79% to 47.53% +/- 16.19% (p less than 0.05). Mean saturation index decreased from a pretreatment value of 1.23 +/- 0.22 to 0.99 +/- 0.17 (p less than 0.05), but only in 4 of 10 subjects did bile become undersaturated. It is concluded that ursocholic acid, due to its higher hydrophilicity, stimulates a lower cholesterol and phospholipid output than ursodeoxycholic acid. Consequently, despite the low enrichment of the biliary bile acids with ursocholic acid, oral administration of ursocholic acid induces a reduction of bile cholesterol saturation.
Assuntos
Sistema Biliar/efeitos dos fármacos , Ácidos Cólicos/farmacologia , Metabolismo dos Lipídeos , Administração Oral , Bile/efeitos dos fármacos , Bile/metabolismo , Ácidos e Sais Biliares/metabolismo , Sistema Biliar/metabolismo , Ácidos Cólicos/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Dietetic manipulation significantly influences the progression of renal failure in laboratory animals. Clinical results in humans are contradictory. The aim of the study was epidemiological research on a large sample of kidney disease patients to verify whether renal failure influences nutrient intake before dietetic manipulation. Four hundred and forty-one consecutive, non-selected adult patients with renal insufficiency (creatinine 133-963 mumol, mean 301 +/- 178 mumol in male, 288 +/- 156 mumol/l in female) and 43 kidney disease patients without renal failure were enrolled in the prospective study in the period 1988-1995. Interview at the time of the first nephrological check was performed by only one dietician; the record by recall of intake over 7 days with quantitative assessment was collected with the assistance of nutritional dossier and photographic measures. The patients with renal failure consume energy, proteins, lipids and carbohydrates in lesser quantities than the national population of the same geographical area, but the total lipid and monounsaturated fatty acid intake is higher compared with Italian dietary reference values. In patients with renal failure mean protein intake was 1.02 +/- 0.2 g/kg/day in males and 0.96 +/- 0.2 g/kg/day in females; mean lipid intake was 1.10 +/- 0.2 g/kg/day in males and 1.17 +/- 0.3 g/kg/day in females; mean carbohydrate intake was 3.7 +/- 1.1 g/kg/day in males and 3.49 +/- 1 g/kg/day in females. The nutrition alterations observed in chronic renal failure may be a biological adaptation due to neurological changes affecting the sense of taste.
Assuntos
Falência Renal Crônica/metabolismo , Fenômenos Fisiológicos da Nutrição , Adulto , Idoso , Idoso de 80 Anos ou mais , Ingestão de Energia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A molecule isolated from the peritoneal fluids of women undergoing laparoscopy for in-vitro fertilization techniques has been chemically characterized and identified as 1-palmitic-3-phosphorylcholine (lysophosphatidylcholine, LPC). This lipid is able, at physiological concentrations, to completely inhibit sperm motility in vitro in a dose-dependent way. Synthetic LPC induced rapid and complete arrest of sperm motility when added to sperm suspensions at physiological concentrations without any damage to cell membranes. Taken together, these results suggest that LPC may represent a previously unrecognized in-vivo modulator of human sperm motility.
Assuntos
Líquido Ascítico/química , Lisofosfatidilcolinas/isolamento & purificação , Lisofosfatidilcolinas/farmacologia , Imobilizantes dos Espermatozoides/isolamento & purificação , Imobilizantes dos Espermatozoides/farmacologia , Motilidade dos Espermatozoides/efeitos dos fármacos , Motilidade dos Espermatozoides/fisiologia , Feminino , Humanos , Técnicas In Vitro , Infertilidade Feminina/etiologia , Infertilidade Feminina/fisiopatologia , Masculino , Fosfatidilserinas/isolamento & purificação , Fosfatidilserinas/farmacologia , Fosfatidilserinas/fisiologia , Proteína Quinase C/fisiologiaRESUMO
Since progesterone has been claimed to induce acrosomal reaction and hyperactivated motility of human spermatozoa, the present study was undertaken to determine if its presence at concentrations similar to those of peri-ovulatory follicular fluid could influence the effect of peritoneal fluid on sperm motility in vitro. To this end, 11 sperm samples were incubated at 37 degrees C with five peritoneal fluids with/without exogenous progesterone, and sperm motility was assessed using a computer-assisted analyser at time (t) = 0, 2.5, 5 and 24 h. Overall there was no observable constant trend for enhancement or inhibition of sperm motility. Progesterone generally induced a negative effect on those sperm samples with high velocities in the native peritoneal fluids and a positive effect on those sperm samples demonstrating low motility in the native peritoneal fluids. The incorporation of progesterone into the incubation medium seemed to result in a 'tuning' of sperm velocity to around 30-50 micron/s. However, a given sperm sample reacted differently when incubated with various peritoneal fluids and, reciprocally, different semen samples incubated with the same peritoneal fluid showed very variable motility patterns. The greater variability of the effects exerted by progesterone on sperm motility could arise from the fact that each sperm sample may contain subpopulations of gametes with different sensitivity to progesterone.
Assuntos
Líquido Ascítico , Progesterona/fisiologia , Motilidade dos Espermatozoides/fisiologia , Adulto , Líquido Ascítico/fisiopatologia , Feminino , Líquido Folicular/fisiologia , Humanos , Técnicas In Vitro , MasculinoRESUMO
The effect of five bile salts, deoxycholate, chenodeoxycholate, cholate, ursodeoxycholate, and ursocholate, possessing (in decreasing order) different hydrophobicity, on bile flow and biliary secretion of total calcium, magnesium, sodium, and potassium was studied in 10 patients with T-tubes. Each subject was infused intraduodenally with one or two bile salts, given separately, to produce a selective enrichment of biliary bile salts with the infused bile salt. The choleresis induced per 1-mumol increase of bile salt output was greater during the secretion of 7 beta-hydroxylated bile salts, ursodeoxycholate (0.029 ml), and ursocholate (0.027 ml), followed in decreasing order by deoxycholate (0.023 ml), chenodeoxycholate (0.019 ml), and cholate (0.009 ml). Deoxycholate stimulated the greatest increase in cation secretion per unit increase in bile salt output, followed by chenodeoxycholate and cholate. The two 7 beta-hydroxylated bile salts induced greater cation secretion than did their 7 alpha-epimers. Whereas biliary concentration of divalent cations differed depending on the structure and concentration of the infused bile salt, the concentration of monovalent cations was constant for any species and concentration of infused bile salt. Relationships between bile salt and divalent cation concentration indicate that 1 mumol of secreted biliary deoxycholate, the most hydrophobic bile salt, associates with the greatest amount of calcium (0.046 mumol) and magnesium (0.022 mumol), followed by chenodeoxycholate (0.020 and 0.010 mumol, respectively) and cholate (0.012 and 0.008 mumol, respectively). The capacity of ursodeoxycholate and ursocholate to associate with calcium and magnesium seems to be less than that of their 7 alpha-epimers. These data suggest that of the common bile salts, the more hydrophobic bile salts stimulate bile flow and cation secretion better than the more hydrophilic bile salts, whereas ursodeoxycholate and ursocholate are more effective than their more hydrophobic 7 alpha-epimers. Whereas different bile salts seem to influence the secretion of sodium and potassium mainly by virtue of their choleretic properties, the effect of bile salt structure on biliary secretion of calcium and magnesium suggests the presence of a secretory link that might be consistent with cation-bile salt binding.