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1.
Yearb Med Inform ; (1): 533-535, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-27706353
2.
J Med Internet Res ; 3(1): E4, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11720946

RESUMEN

BACKGROUND: The Wireless Application Protocol technology implemented in newer mobile phones has built-in facilities for handling much of the information processing needed in clinical work. OBJECTIVES: To test a practical approach we ported a relational database of the Danish pharmaceutical catalogue to Wireless Application Protocol using open source freeware at all steps. METHODS: We used Apache 1.3 web software on a Linux server. Data containing the Danish pharmaceutical catalogue were imported from an ASCII file into a MySQL 3.22.32 database using a Practical Extraction and Report Language script for easy update of the database. Data were distributed in 35 interrelated tables. Each pharmaceutical brand name was given its own card with links to general information about the drug, active substances, contraindications etc. Access was available through 1) browsing therapeutic groups and 2) searching for a brand name. The database interface was programmed in the server-side scripting language PHP3. RESULTS: A free, open source Wireless Application Protocol gateway to a pharmaceutical catalogue was established to allow dial-in access independent of commercial Wireless Application Protocol service providers. The application was tested on the Nokia 7110 and Ericsson R320s cellular phones. CONCLUSIONS: We have demonstrated that Wireless Application Protocol-based access to a dynamic clinical database can be established using open source freeware. The project opens perspectives for a further integration of Wireless Application Protocol phone functions in clinical information processing: Global System for Mobile communication telephony for bilateral communication, asynchronous unilateral communication via e-mail and Short Message Service, built-in calculator, calendar, personal organizer, phone number catalogue and Dictaphone function via answering machine technology. An independent Wireless Application Protocol gateway may be placed within hospital firewalls, which may be an advantage with respect to security. However, if Wireless Application Protocol phones are to become effective tools for physicians, special attention must be paid to the limitations of the devices. Input tools of Wireless Application Protocol phones should be improved, for instance by increased use of speech control.


Asunto(s)
Sistemas de Información en Farmacia Clínica/tendencias , Sistemas de Administración de Bases de Datos , Internet , Aplicaciones de la Informática Médica , Sistemas de Administración de Bases de Datos/tendencias , Diccionarios Farmacéuticos como Asunto , Internet/tendencias , Programas Informáticos/tendencias , Teléfono/tendencias
4.
Ugeskr Laeger ; 162(42): 5603-6, 2000 Oct 16.
Artículo en Danés | MEDLINE | ID: mdl-11059295

RESUMEN

The use MEDLINE and related resources of literature information has increased significantly with the increased availability and speed of the Internet. However, literature information is presented in many different ways via the Internet and search facilities and web addresses are frequently changed. Many physicians and medical researchers find it difficult to keep track of what is available and many lack skills in effective searching. The present paper presents an overview of the MEDLINE database and related databases available from the National Library of Medicine and searchable through PubMed and Internet Greatfull Med. We discuss strategies for searching MEDLINE and the coverage of MEDLINE related to that of related databases from the NLM and other sources.


Asunto(s)
Internet , MEDLINE
5.
Ugeskr Laeger ; 162(42): 5607-9, 2000 Oct 16.
Artículo en Danés | MEDLINE | ID: mdl-11059296

RESUMEN

The availability of full text medical journal articles is rapidly increasing with the increased availability of the Internet. The potentials of the new technology present researchers, publishers, and librarians with new problems and challenges. Some resources are made available free of charge, whereas others are distributed as parts of large licences negotiated between publishers and consortia of research libraries. How can researchers maintain an overview of the constantly changing resources? How can libraries cope with tasks rapidly redefined by the technology? And how can publishers survive when production and distribution of literature information, including the handling of peer reviewing, might just as well be performed by the researchers themselves or their organisations? The present paper presents some of the resources available and discusses both national and international projects and activities that deal with these questions.


Asunto(s)
Internet , Edición
6.
Anat Rec ; 261(2): 64-77, 2000 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-10815811

RESUMEN

Continuing evolution of computer-based multimedia technologies has produced QuickTime, a multiplatform digital media standard that is supported by stand-alone commercial programs and World Wide Web browsers. While its core functions might be most commonly employed for production and delivery of conventional video programs (e.g., lecture videos), additional QuickTime VR "virtual reality" features can be used to produce photorealistic, interactive "non-linear movies" of anatomical structures ranging in size from microscopic through gross anatomic. But what is really included in QuickTime VR and how can it be easily used to produce novel and innovative visualizations for education and research? This tutorial introduces the QuickTime multimedia environment, its QuickTime VR extensions, basic linear and non-linear digital video technologies, image acquisition, and other specialized QuickTime VR production methods. Four separate practical applications are presented for light and electron microscopy, dissectable preserved specimens, and explorable functional anatomy in magnetic resonance cinegrams.


Asunto(s)
Anatomía Transversal/instrumentación , Anatomía Transversal/métodos , Internet , Interfaz Usuario-Computador , Grabación en Video/métodos , Anatomía Transversal/educación , Instrucción por Computador/instrumentación , Instrucción por Computador/métodos , Cabeza/anatomía & histología , Humanos , Articulación de la Rodilla/anatomía & histología , Imagen por Resonancia Magnética , Microscopía Electrónica , Microscopía por Video , Modelos Anatómicos , Películas Cinematográficas/instrumentación , Multimedia , Factores de Tiempo
7.
J Rheumatol ; 26(7): 1600-5, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10405951

RESUMEN

OBJECTIVE: We studied the socioeconomic background of children with juvenile chronic arthritis (JCA) diagnosed during the years 1988-91 in Denmark. The working hypothesis is that JCA may be triggered by one or several different infectious agents and that the amount of exposure to infectious agents in infancy and childhood affects the risk of JCA. METHODS: In this case-control study, we investigated socioeconomic variables prior to disease onset from national registers, primarily the Fertility Database of Statistics Denmark, in a national cohort of all 220 known cases of JCA fulfilling the EULAR criteria incident during the years 1988-91, identified from national and local diagnosis registers. There were 4 controls per case, matched for sex, age, and county of residence. Socioeconomic variables as risk factors were quantified by odds ratios, which are equivalent to relative risks of contracting JCA if exposed to a risk factor. RESULTS: Three socioeconomic variables were significantly and mutually independently associated with the risk of developing JCA during the following year. An only child had a risk of JCA 1.6 times that of a child with siblings. Children whose parents had a high income had a relative risk of 1.9. Children living in an urban flat had a risk 2.7 times that of children living on a farm. We found no space-time clustering of cases and no cyclical variations of incidence rates. CONCLUSION: The absence of clustering and of seasonal variation does not support a theory of triggering by infection. The hitherto unreported effects of the socioeconomic variables on the risk of JCA are of the same order of magnitude as reported for certain HLA alleles. Our findings do not lend full support to either of the 2 mechanisms, that growing up under either hygienic or unhygienic conditions increases the risk of JCA, and lack an obvious biological explanation.


Asunto(s)
Artritis Juvenil/epidemiología , Salud de la Familia , Vivienda , Clase Social , Adolescente , Artritis Juvenil/etiología , Artritis Juvenil/psicología , Estudios de Casos y Controles , Niño , Preescolar , Estudios de Cohortes , Dinamarca/epidemiología , Femenino , Humanos , Higiene , Incidencia , Infecciones/complicaciones , Masculino , Factores de Riesgo , Agrupamiento Espacio-Temporal
8.
J Am Soc Nephrol ; 9(8): 1347-58, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9697656

RESUMEN

Mineralocorticoid hormones regulate salt transport along the distal nephron by binding to intracellular receptors and activating gene transcription. Previous experiments showed that systemic aldosterone infusions stimulate thiazide-sensitive Na and Cl transport by distal convoluted tubule (DCT) cells; this effect could have been direct or secondary to systemic hormonal effects. Aldosterone target tissues express both mineralocorticoid receptors and the metabolic enzyme 11beta-hydroxysteroid dehydrogenase type 2. Mineralocorticoid receptors have been localized to the DCT in some experiments, but not in others. Expression of 11beta-hydroxysteroid dehydrogenase type 2 by DCT cells has not been investigated. The present experiments were designed to test the hypothesis that rat DCT cells are targets of aldosterone action. Patterns of mineralocorticoid receptor, 11beta-hydroxysteroid dehydrogenase, thiazide-sensitive Na-Cl cotransporter, and Na/Ca exchanger expression along the distal tubule were examined. A polyclonal antibody was generated to localize the thiazide-sensitive Na-Cl cotransporter. Thiazide-sensitive Na-Cl cotransporter and 11beta-hydroxysteroid dehydrogenase expression were examined using both in situ hybridization and immunocytochemistry; Na/Ca exchanger and mineralocorticoid receptor expression were examined by immunocytochemistry. The results indicate that 11beta-hydroxysteroid dehydrogenase is expressed by DCT cells, as well as connecting tubule cells and principal cells of the collecting duct; expression levels are low near the junction with the thick ascending limb and rise near the transition to the connecting tubule. Mineralocorticoid receptors are expressed by DCT cells, as well as along the thick ascending limb, connecting tubule, and collecting duct. The results indicate that components of the mineralocorticoid receptor system are expressed by DCT cells, suggesting that these cells are targets of aldosterone action.


Asunto(s)
Proteínas Portadoras/metabolismo , Hidroxiesteroide Deshidrogenasas/metabolismo , Túbulos Renales Distales/metabolismo , Receptores de Mineralocorticoides/metabolismo , Simportadores , 11-beta-Hidroxiesteroide Deshidrogenasas , Aldosterona/metabolismo , Animales , Secuencia de Bases , Proteínas Portadoras/genética , Cartilla de ADN/genética , Expresión Génica , Hidroxiesteroide Deshidrogenasas/genética , Inmunohistoquímica , Hibridación in Situ , Túbulos Renales Distales/citología , Masculino , Ratones , Ratas , Ratas Sprague-Dawley , Receptores de Droga/genética , Receptores de Droga/metabolismo , Receptores de Mineralocorticoides/genética , Simportadores del Cloruro de Sodio , Miembro 3 de la Familia de Transportadores de Soluto 12
10.
Diabetologia ; 40(7): 802-9, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9243101

RESUMEN

A morphometric study was performed on moderately hyperglycaemic streptozotocin diabetic rats after 10 and 50 days of diabetes, and on groups of rats that, after initial hyperglycaemia for 50 days, were insulin treated for 2 h or for 5, 15 or 38 days. A group of hyperglycaemic diabetic animals were fasted for 18 h. Another group of rats had acute hyperglycaemia induced by intravenous glucose injection. After 10 and 50 days of diabetes, kidney weight was increased by 55 and 93%. Glomerular volume, tubule length, and tubular and interstitial volume increased in diabetic animals compared with controls. After 4 h insulin treatment, the kidney weight was 20% decreased; after 5 days it was 31% decreased. After 38 days the kidney weight was still 26% greater than in controls. In diabetic animals, 18 h fasting induced a 30% decrease in kidney weight. In normal animals, acute hyperglycaemia induced a 22% increase in kidney weight. Volume fractions of most kidney structures remained similar in all groups. However, the glomerular volume fraction was smaller during kidney enlargement, and the tubular volume fraction was larger after induced hyperglycaemia compared with controls. In conclusion, high blood glucose levels in diabetic and normal animals are associated with increased kidney weight. In hyperglycaemic diabetic animals, normalization of blood glucose after insulin treatment or fasting was followed by a decrease in kidney weight.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/patología , Insulina/uso terapéutico , Riñón/patología , Animales , Glucemia/metabolismo , Peso Corporal , Tejido Conectivo/efectos de los fármacos , Tejido Conectivo/patología , Femenino , Hiperglucemia/patología , Riñón/efectos de los fármacos , Glomérulos Renales/patología , Túbulos Renales Distales/patología , Túbulos Renales Proximales/patología , Tamaño de los Órganos , Ratas , Ratas Wistar
11.
Exp Nephrol ; 5(4): 305-17, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9259185

RESUMEN

AIMS: To provide a 3-D description and basic morphometric data along the course of subcapsular proximal tubules. METHODS: Proximal convoluted (PCT) and straight (PST) tubules were analyzed in series of up to one thousand 4-micron sections of perfusion-fixed rat renal cortex. Nine proximal tubules were traced through the sections by computer-assisted 3-D reconstruction. Selected sections were reembedded and resectioned for ultrastructural morphometry. RESULTS: Subcapsular PCTs (n = 3) had a total length of 12.0 +/- 0.2 mm (SEM), formed tight clusters and contacted the renal surface from 5 to 10 times. In contrast, mid-cortical tubules (total PT length 11.6 +/- 0.1 mm) and in particular deep cortical tubules (total PT length 12.1 +/- 0.9 mm) extended laterally and intermingled considerably with neighboring tubules. Epithelial height gradually decreased from around 11 microns in the PCT to 7.5 microns in the end of the PST. Brush-border height was around 4 microns in the first PT segment (S1), 2.3 microns in the second segment (S2) and 4.5 microns in the end of the proximal tubule. Tubular wall volume, excluding microvilli, decreased from around 1,450 micron3/microns tubule length in early PCT to 825 micron3/microns in terminal PST. CONCLUSIONS: The results provide, at precisely defined nephron levels, quantitative ultrastructural data relevant to transport physiology.


Asunto(s)
Simulación por Computador , Túbulos Renales Proximales/ultraestructura , Modelos Estructurales , Animales , Membrana Celular/ultraestructura , Endocitosis , Epitelio/ultraestructura , Corteza Renal/anatomía & histología , Corteza Renal/ultraestructura , Médula Renal/anatomía & histología , Médula Renal/ultraestructura , Túbulos Renales Proximales/citología , Masculino , Microvellosidades/ultraestructura , Mitocondrias/ultraestructura , Ratas , Ratas Sprague-Dawley , Vacuolas/ultraestructura
12.
J Clin Invest ; 97(8): 1960-8, 1996 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-8621781

RESUMEN

Prolonged hypokalemia causes vasopressin-resistant polyuria. We have recently shown that another cause of severe polyuria, chronic lithium therapy, is associated with decreased aquaporin-2 (AQP2) water channel expression (Marples, D., S. Christensen, E.I. Christensen, P.D. Ottosen, and S. Nielsen, 1995. J. Clin. Invest., 95: 1838-1845). Consequently, we studied the effect in rats of 11 days' potassium deprivation on urine production and AQP2 expression and distribution. Membrane fractions were prepared from one kidney, while the contralateral kidney was perfusion-fixed for immunocytochemistry. Immunoblotting and densitometry revealed a decrease in AQP2 levels to 27+/-3.4% of control levels (n=11, P<0.001) in inner medulla, and 34+/-15% of controls (n=5, P<0.05) in cortex. Urine production increased in parallel, from 11+/-1.4 to 30+/-4.4 ml/day (n=11, P<0.01). After return to a potassium-containing diet both urine output and AQP2 labels normalized within 7 d. Immunocytochemistry confirmed decreased AQP2 labeling in principal cells of both inner medullary and cortical collecting ducts. AQP2 labeling was predominantly associated with the apical plasma membrane and intracellular vesicles. Lithium treatment for 24 d caused a more extensive reduction of AQP2 levels, to 4+/-1% of control levels in the inner medulla and 4+/-2% in cortex, in association with severe polyuria. The similar degree of downregulation in medulla and cortex suggests that interstitial tonicity is not the major factor in the regulation of AQP2 expression. Consistent with this furosemide treatment did not alter AQP2 levels. In summary,hypokalemia, like lithium treatment, results in a decrease in AQP2 expression in rat collecting ducts, in parallel with the development of polyuria, and the degree of downregulation is consistent with the level of polyuria induced, supporting the view that there is a causative link.


Asunto(s)
Acuaporinas , Regulación de la Expresión Génica , Hipopotasemia/metabolismo , Canales Iónicos/biosíntesis , Corteza Renal/metabolismo , Médula Renal/metabolismo , Animales , Acuaporina 2 , Acuaporina 6 , Membrana Celular/metabolismo , Membrana Celular/patología , Membrana Celular/ultraestructura , Electroforesis en Gel de Poliacrilamida , Hipopotasemia/patología , Immunoblotting , Canales Iónicos/análisis , Corteza Renal/patología , Corteza Renal/ultraestructura , Médula Renal/patología , Médula Renal/ultraestructura , Masculino , Microscopía Electrónica , Poliuria , Deficiencia de Potasio/metabolismo , Deficiencia de Potasio/orina , Ratas , Ratas Wistar , Sed
13.
Acta Diabetol ; 32(4): 225-9, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8750760

RESUMEN

Kidney volume was measured during pregnancy in insulin-dependent diabetic women by an ultrasound technique and prognostic value of these measurements evaluated. A prospective study was performed on 87 pregnant women with insulin-dependent diabetes attending the maternity clinic of Aarhus Kommunehospital. Patients with proliferative retinopathy alone, hydronephrosis, or nephrotic syndrome were excluded. The patients were grouped according to onset and duration of diabetes and to vascular lesions; group I (n = 35, White class B+C), group II (n = 11, White class D0), group III (n = 26, White class D+), and group IV (n = 15, White class F+F/R). The patients visited the hospital every 2 weeks during pregnancy for general obstetric and glycaemic control and blood sampling. The volume of both kidneys was measured by a computerized nephrosonograph during the three terms of pregnancy, the puerperium and 4 months postpartum. The kidney volume increased significantly in all four groups from first to third trimester. In the third trimester the kidney volumes were 375 +/- 68 ml (I), 341 +/- 50 ml (II), 362 +/- 63 ml (III), and 343 +/- 54 ml (IV). The kidney volume in the third trimester was positively correlated with creatinine clearance (r = 0.33, P < 0.01) and inversely correlated with creatinine in serum (r = -0.27, P = < 0.02). Total kidney volume decrease (in percent) defined as the difference of maximal volume and value at 4 months postpartum was inversely correlated to albuminuria in the third trimester (r = -0.25, P < 0.05) and vascular lesions of the patients: (mean +/- SEM) 37 +/- 4% (I), 25 +/- 7% (II), 19 +/- 5% (III), and 11 +/- 7% (IV), P < 0.01. In the puerperium, kidney volume decreased significantly from third trimester in groups I, II, and III, whereas we observed no change in group IV. Six of 15 women in groups II and III with kidney volume < 300 ml and normoalbuminuria in the first trimester developed persistent microalbuminuria after pregnancy (P < 0.02). The renal volume in insulin-dependent diabetic women increases significantly during pregnancy and is inversely related to the vascular lesions of the patients. The decrease in renal volume after pregnancy is related to the albuminuria at the end of pregnancy. Women with longstanding diabetes, White class D (= groups II+III), and kidney volume < 300 ml in the first trimester have a high risk of developing permanent microalbuminuria after pregnancy.


Asunto(s)
Diabetes Mellitus Tipo 1/fisiopatología , Nefropatías Diabéticas/fisiopatología , Riñón/diagnóstico por imagen , Embarazo en Diabéticas/fisiopatología , Adulto , Análisis de Varianza , Glucemia/análisis , Presión Sanguínea , Nefropatías Diabéticas/diagnóstico por imagen , Femenino , Hemoglobina Glucada/análisis , Humanos , Riñón/anatomía & histología , Riñón/fisiopatología , Periodo Posparto , Embarazo , Primer Trimestre del Embarazo , Segundo Trimestre del Embarazo , Tercer Trimestre del Embarazo , Estudios Prospectivos , Proteinuria , Ultrasonografía
14.
Exp Nephrol ; 3(4): 223-33, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8590035

RESUMEN

The ultrastructure of intercalated cells in the rat renal cortex was investigated after 7 days of treatment with the mineralocorticoid inhibitor spironolactone. In untreated and treated animals, two subgroups of IC cells (A-IC and B-IC) could be recognized by electron microscopy, but a substantial fraction of IC cells that corresponded to neither A nor B forms, so-called NonA-NonB, was also found. After spironolactone treatment, qualitative and morphometric analyses showed a decrease in volume density of mitochondria, in cell cross-sectional area, and in boundary length of basolateral membranes in A-IC cells. Among the NonA-NonB-IC cells, some revealed especially abundant mitochondria. Although the frequency of NonA-NonB-IC cells did not change significantly, these mitochondria-rich cells appeared with increased frequency after spironolactone treatment. The ultrastructural changes in A-IC cells might reflect a direct effect of spironolactone on the A-IC cells. However, it is also conceivable that the changes are secondary to functional alterations induced in neighboring segment-specific cells by the experimental conditions.


Asunto(s)
Corteza Renal/ultraestructura , Espironolactona/farmacología , Animales , Membrana Celular/efectos de los fármacos , Membrana Celular/ultraestructura , Citoplasma/ultraestructura , Corteza Renal/efectos de los fármacos , Túbulos Renales/ultraestructura , Túbulos Renales Colectores/ultraestructura , Masculino , Microscopía Electrónica , Mineralocorticoides/antagonistas & inhibidores , Mitocondrias/efectos de los fármacos , Mitocondrias/ultraestructura , Ratas , Ratas Wistar , Sodio/sangre , Sodio/orina
15.
Exp Nephrol ; 3(3): 180-92, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7620856

RESUMEN

The effects of bafilomycin, an inhibitor of the vacuolar-type (V-type) proton pump, on nephron ultrastructure and acidification were analyzed in isolated perfused kidneys from rats with acute metabolic acidosis. Acidic intracellular compartments were labelled with the weak base DAMP, that was subsequently visualized immunocytochemically. The distribution of the proton pump was studied by immunocytochemistry. Bafilomycin inhibited urinary acidification and caused pronounced ultrastructural changes in proximal tubule cells and B-type intercalated cells (B-IC cells). Immunoreactivity for DAMP showed that bafilomycin also inhibits intracellular acidification. The distribution of the proton pump was essentially unchanged by bafilomycin in A-IC cells. In B-IC cells, immunoreactivity accumulated over studded membrane material in the apical cytoplasm. The results indicate that the V-type proton pump is important both for intracellular and for urinary acidification.


Asunto(s)
Ácidos/metabolismo , Macrólidos , Nefronas/metabolismo , Nefronas/ultraestructura , Inhibidores de la Bomba de Protones , Vacuolas/metabolismo , Animales , Antibacterianos/farmacología , Inmunohistoquímica , Técnicas In Vitro , Riñón/metabolismo , Riñón/ultraestructura , Masculino , Nefronas/efectos de los fármacos , Perfusión , ATPasas de Translocación de Protón/metabolismo , Ratas , Ratas Wistar , Distribución Tisular
16.
Ugeskr Laeger ; 156(34): 4813-6, 1994 Aug 22.
Artículo en Danés | MEDLINE | ID: mdl-7992415

RESUMEN

The aim of the study was to estimate the incidence of Kawasaki's disease and to describe the clinical manifestations and the prognosis of the disease in children in Denmark during the period 1981-1990. In a register of all hospital admissions in Denmark, 99 patients were registered as having Kawasaki's disease. Of those, 89 patients fulfilled the clinical diagnostic criteria. The mean incidence of the ten year period was 1.0 per 100,000 children per year. The incidence of the disease decreased in the age group from zero to seven years after which it was rarely observed. Typical laboratory findings were hypersedimentation, leucocytosis and thrombocytosis. Eight children had cardiomegaly and three had electrocardiographic changes. Echocardiography was performed in 66 patients showing coronary artery aneurysms in nine patients (14%) (six boys and three girls). No further cardiac complications were found.


Asunto(s)
Síndrome Mucocutáneo Linfonodular/epidemiología , Adolescente , Niño , Preescolar , Dinamarca/epidemiología , Femenino , Humanos , Incidencia , Lactante , Masculino , Síndrome Mucocutáneo Linfonodular/diagnóstico , Pronóstico , Estudios Retrospectivos
17.
Lab Invest ; 67(6): 761-9, 1992 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1460867

RESUMEN

BACKGROUND: Functional investigations of the tubulo-glomerular feedback mechanism have indicated the existence of a contact between the distal nephron and the macula densa region. The structural justification of such a contact is investigated. EXPERIMENTAL DESIGN: Tubule-tubule and tubule-arteriole contacts were investigated in distal nephrons from normal rat kidneys. Computer-assisted three-dimensional reconstructions of distal nephrons were made from serial sections of renal cortical tissue and selected sections were examined by electron microscopy. RESULTS: In 14 of 15 reconstructed nephrons, the distal convoluted tubule or the connecting tubule approached the macula densa region. A wall-to-wall contact between two tubules corresponding to a three-dimensional distance below 28 microns between the axes of the two tubules was found in only five of the reconstructed tubules. The distal nephron contacts to afferent and efferent arterioles of the same nephron were also examined. The efferent arteriole revealed no consistent contacts but the afferent arteriole contacted the distal convoluted tubule/connecting tubules consistently in all 10 of the superficial nephrons and in 3 of 5 midcortical nephrons. Electron microscopy confirmed a close contact between the distal tubule and the afferent arteriole in superficial nephrons and small nerves were often found at or near the site of contact, but the morphology at the site of contact was not unique. The arteriole contacts were made with late distal convoluted tubules, connecting tubules, or cortical collecting ducts. CONCLUSIONS: In conclusion, the present study shows that tubule-tubule contacts are inconsistent between the macula densa region and the distal nephron but that the tubule-afferent arteriole contact is consistent and close in superficial nephrons. This morphology is compatible with the existence of a feedback mechanism between the superficial distal nephron and the afferent arteriole, apart from the one located at the juxtaglomerular apparatus.


Asunto(s)
Túbulos Renales/citología , Animales , Femenino , Procesamiento de Imagen Asistido por Computador , Túbulos Renales/fisiología , Túbulos Renales/ultraestructura , Nefronas/citología , Nefronas/fisiología , Nefronas/ultraestructura , Ratas , Ratas Wistar
18.
Am J Clin Nutr ; 56(4): 712-5, 1992 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1414972

RESUMEN

The influence of sex on glucose and insulin responses in patients with non-insulin-dependent diabetes was studied in 12 men and 11 matched women. Two meals of either 100 g white bread or 60 g (raw weight) white rice were given. Blood glucose response areas to white bread (517 vs 509 mmol/L) and to rice (306 vs 353 mmol/L) over a 300-min observation period were similar in females and males, respectively. Insulin responses showed an identical pattern to that of glucose in females and males--35784 vs 28230 pmol/L after white bread and 28044 vs 19464 pmol/L min after rice (NS) over a 300-min observation period, respectively. Within the two study groups, blood glucose-response areas to white bread were significantly higher than those to rice (P less than 0.05), whereas there were no differences in insulin-response areas within or between the two groups. The glycemic index of rice for females (62 +/- 9; mean +/- SE) and males (66 +/- 5) was similar.


Asunto(s)
Glucemia/metabolismo , Carbohidratos de la Dieta/farmacología , Insulina/sangre , Pan , Femenino , Alimentos , Humanos , Cinética , Masculino , Persona de Mediana Edad , Oryza
19.
Diabetes Care ; 15(4): 522-4, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1294081

RESUMEN

OBJECTIVE: To study day-to-day variation of postprandial blood glucose and insulin increments in non-insulin-dependent diabetes mellitus (NIDDM) subjects and to analyze intra- and interperson variance of response. RESEARCH DESIGN AND METHODS: Ten NIDDM subjects attending the outpatient clinic at Aarhus Kommunehospital were studied. The subjects ate three meals of 90 g of white bread, with 7 days between tests. RESULTS: Mean +/- SD areas under the blood glucose response curve (above basal) over a 3-h period were 557 +/- 60, 569 +/- 74, and 565 +/- 67 mM x 180 min (NS), and areas under the insulin-response curve were 3350 +/- 448, 2815 +/- 359 and 3551 +/- 679 mU/L x 180 min (NS) on each of the three occasions. The 95% confidence intervals of blood glucose and insulin areas for the test meal repeated three times were 564 +/- 120 mM x 180 min and 3240 +/- 1645 mU/L x 180 min, respectively. Intra- and interperson components of variance were 25 vs. 75% (glucose) and 78 vs. 22% (insulin) of the total variance. The intraperson components of variance included all sources of variation other than between-person variation. There was no significant correlation between blood glucose and insulin response areas. CONCLUSIONS: A valid estimate of the glycemic response in a single patient is obtained after a single meal. Because of the large between-person variation, paired data should preferably be used when comparing glycemic responses to different foods.


Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Carbohidratos de la Dieta , Insulina/sangre , Ingestión de Alimentos , Femenino , Humanos , Masculino , Persona de Mediana Edad
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