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Ferraretti AP, Nygren K, Andersen AN, de Mouzon J, Kupka M, Calhaz-Jorge C, Wyns C, Gianaroli L, Goossens V. Trends over 15 years in ART in Europe: an analysis of 6 million cycles. Hum Reprod Open 2017; 2017:hox012. [PMID: 31486803 PMCID: PMC6276702 DOI: 10.1093/hropen/hox012] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 06/21/2017] [Accepted: 07/26/2017] [Indexed: 11/25/2022] Open
Abstract
Study question Was the European IVF Monitoring (EIM) Consortium, established in 1999 by ESHRE, able to monitor the trend over time of ART in Europe? Summary answer The initial aims of the EIM programme (to collect and publish regional European data on census and trends on ART utilization, effectiveness, safety and quality) have been achieved. What is already known ART data in Europe have been collected and reported annually in Human Reproduction. Study design, size, duration A retrospective data analysis and summary of the first 15 years of ART activity in Europe (1997–2011) was carried out, using the key figures from the annual ESHRE reports and focusing on how the practice of ART has evolved over the years. Participants/materials, setting, method A total of 5 919 320 ART cycles are reported, including IVF, ICSI, frozen embryo relacment and egg donation, resulting in the birth of more than 1 million infants. A total of 1 548 967 IUIs are also reported, including husband/partner’s semen and donor semen cycles. The most relevant and complete data are analysed and discussed. Main results and the role of chance With some fluctuations, the number of countries and clinics reporting to EIM increases significantly from 1997 to 2011. A constant increase was also registered in the number of annual cycles reported. Since 2005, the estimation of the EIM coverage on the total European activity was >80%. In countries with 100% of coverage, the mean availability of ART increased from 765 cycles per million inhabitants in 1997 to 1269 cycles per million inhabitants in 2011, and the proportion of ART infants of the total number of infants born in the country increased from 1.3% to 2.4%. The proportion of women aged > 39 years undergoing IVF and ICSI cycles gradually increased. For 12 consecutive years, the proportion of ICSI versus IVF cycles showed a marked increase before reaching a plateau from 2008. The proportion of transfers with three or more embryos decreased constantly and the proportion of SETs increased over the time period. The triplets deliveries were reduced from 3.7% in 1997 to less than 1% since 2005 (0.6% in 2011). The effectiveness (evaluated as clinical pregnancy rate per aspiration and per embryo transfer) increased until 2007, then the figure remained stable. The cumulative percentage of documented pregnancy losses was 17%. No differences have been noted in terms of outcomes in the IUI cycles. Limitations, reasons for caution The data presented are accumulated from countries with different collection systems, regulations, insurance coverage and different practices. Each year a number of countries have been unable to provide some of the data. Wider implications of the finding(s) The first summary of 15 years of the EIM reports offers interesting data on census and trends on ART utilization, safety and quality in Europe. The primary aim of the ESHRE effort in supporting European data collection has been reached. Owing to its importance inside and outside the professional community, European data collection and publication on ART have to be supported and implemented. Study funding/competing interest(s) None.
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Affiliation(s)
- A P Ferraretti
- ESHRE Central Office, Meerstraat 60, Grimbergen B-1852, Belgium
| | - K Nygren
- ESHRE Central Office, Meerstraat 60, Grimbergen B-1852, Belgium
| | | | - J de Mouzon
- ESHRE Central Office, Meerstraat 60, Grimbergen B-1852, Belgium
| | - M Kupka
- ESHRE Central Office, Meerstraat 60, Grimbergen B-1852, Belgium
| | - C Calhaz-Jorge
- ESHRE Central Office, Meerstraat 60, Grimbergen B-1852, Belgium
| | - C Wyns
- ESHRE Central Office, Meerstraat 60, Grimbergen B-1852, Belgium
| | - L Gianaroli
- ESHRE Central Office, Meerstraat 60, Grimbergen B-1852, Belgium
| | - V Goossens
- ESHRE Central Office, Meerstraat 60, Grimbergen B-1852, Belgium
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Andersen AN, de Mouzon J, Nygren K. Reply: ART register data on delivery rates. Hum Reprod 2009. [DOI: 10.1093/humrep/dep389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Zegers-Hochschild F, Adamson GD, de Mouzon J, Ishihara O, Mansour R, Nygren K, Sullivan E, Vanderpoel S. International Committee for Monitoring Assisted Reproductive Technology (ICMART) and the World Health Organization (WHO) revised glossary of ART terminology, 2009. Fertil Steril 2009; 92:1520-4. [PMID: 19828144 DOI: 10.1016/j.fertnstert.2009.09.009] [Citation(s) in RCA: 836] [Impact Index Per Article: 55.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 09/09/2009] [Accepted: 09/09/2009] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Many definitions used in medically assisted reproduction (MAR) vary in different settings, making it difficult to standardize and compare procedures in different countries and regions. With the expansion of infertility interventions worldwide, including lower resource settings, the importance and value of a common nomenclature is critical. The objective is to develop an internationally accepted and continually updated set of definitions, which would be utilized to standardize and harmonize international data collection, and to assist in monitoring the availability, efficacy, and safety of assisted reproductive technology (ART) being practiced worldwide. METHOD Seventy-two clinicians, basic scientists, epidemiologists and social scientists gathered together at the World Health Organization headquarters in Geneva, Switzerland, in December 2008. Several months before, three working groups were established as responsible for terminology in three specific areas: clinical conditions and procedures, laboratory procedures, and outcome measures. Each group reviewed the existing International Committee for Monitoring Assisted Reproductive Technology glossary, made recommendations for revisions and introduced new terms to be considered for glossary expansion. RESULT(S) A consensus was reached on 87 terms, expanding the original glossary by 34 terms, which included definitions for numerous clinical and laboratory procedures. Special emphasis was placed in describing outcome measures, such as cumulative delivery rates and other markers of safety and efficacy in ART. CONCLUSION(S) Standardized terminology should assist in analysis of worldwide trends in MAR interventions and in the comparison of ART outcomes across countries and regions. This glossary will contribute to a more standardized communication among professionals responsible for ART practice, as well as those responsible for national, regional, and international registries.
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Zegers-Hochschild F, Adamson GD, de Mouzon J, Ishihara O, Mansour R, Nygren K, Sullivan E, van der Poel S. The International Committee for Monitoring Assisted Reproductive Technology (ICMART) and the World Health Organization (WHO) Revised Glossary on ART Terminology, 2009. Hum Reprod 2009; 24:2683-7. [PMID: 19801627 DOI: 10.1093/humrep/dep343] [Citation(s) in RCA: 582] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Many definitions used in medically assisted reproduction (MAR) vary in different settings, making it difficult to standardize and compare procedures in different countries and regions. With the expansion of infertility interventions worldwide, including lower resource settings, the importance and value of a common nomenclature is critical. The objective is to develop an internationally accepted and continually updated set of definitions, which would be utilized to standardize and harmonize international data collection, and to assist in monitoring the availability, efficacy, and safety of assisted reproductive technology (ART) being practiced worldwide. METHOD Seventy-two clinicians, basic scientists, epidemiologists and social scientists gathered together at the WHO headquarters in Geneva, Switzerland in December, 2008. Several months in advance, three working groups were established which were responsible for terminology in three specific areas: clinical conditions and procedures, laboratory procedures and outcome measures. Each group reviewed the existing ICMART glossary, made recommendations for revisions and introduced new terms to be considered for glossary expansion. RESULTS A consensus was reached on 87 terms, expanding the original glossary by 34 terms, which included definitions for numerous clinical and laboratory procedures. Special emphasis was placed in describing outcome measures such as cumulative delivery rates and other markers of safety and efficacy in ART. CONCLUSIONS Standardized terminology should assist in analysis of worldwide trends in MAR interventions and in the comparison of ART outcomes across countries and regions. This glossary will contribute to a more standardized communication among professionals responsible for ART practice, as well as those responsible for national, regional and international registries.
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Nygren K, Zegers-Hochschild F. Documentation of infertility prevalence, treatment access and treatment outcomes in developing countries. ACTA ACUST UNITED AC 2008. [DOI: 10.1093/humrep/den218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
IVF is performed with oocytes collected in natural and stimulated cycles. Different approaches to ovarian stimulation have been employed worldwide. Following the introduction of GnRH antagonists and strategies to reduce multiple births such as single embryo transfer, there is a genuine scientific interest in the revival of natural cycle and mild approaches to ovarian stimulation in IVF. Recent evidence suggests that application of natural and mild IVF is patient-centred, aimed at reducing the cost of treatment, patient discomfort and multiple pregnancies. However, there seems to be no consistency in the terminology used for definitions and protocols for ovarian stimulation in IVF cycles. Following the recent International Society for Mild Approaches in Assisted Reproduction (ISMAAR) meeting and communication with interested international experts, this article has recommended revised definitions and terminology for natural cycle IVF and different protocols used in ovarian stimulation for IVF. It is proposed that these terms are adopted internationally in order to achieve a consistency in clinical practice, research publications and communication with patients.
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Affiliation(s)
- G Nargund
- Department of Reproductive Medicine, St George's Hospital and Medical School, London, UK.
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Nygren K, Andersen AN, Felberbaum R, Gianaroli L, de Mouzon J. On the benefit of assisted reproduction techniques, a comparison of the USA and Europe. Hum Reprod 2006; 21:2194. [PMID: 16887926 DOI: 10.1093/humrep/del238] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Clauss M, Hofmann RR, Hummel J, Adamczewski J, Nygren K, Pitra C, Streich W, Reese S. Macroscopic anatomy of the omasum of free-ranging moose (Alces alces) and muskoxen (Ovibos moschatus) and a comparison of the omasal laminal surface area in 34 ruminant species. J Zool (1987) 2006. [DOI: 10.1111/j.1469-7998.2006.00148.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Adamson G, Lancaster P, De Mouzon J, Nygren K, Sullivan E, Zegers-Hochschild F. ICMART World Collaborative Report on In Vitro Fertilization 2000. Fertil Steril 2005. [DOI: 10.1016/j.fertnstert.2005.07.258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The effects of furosemide administered at the onset of postischaemic renal failure were investigated in Sprague-Dawley rats one month after exposing the left kidney to 45 min of renal ischemia. In the experimental group, 13 mg furosemide was given intravenously both before and a few minutes after induction of the ischaemia and then, by an osmotic pump, in a daily dose of 2-3 mg for the following 7 days. The animals of the control group were treated similarly but with saline alone. After one month, the glomerular filtration rate (GFR) in the damaged left kidneys of the furosemide-treated rats was 0.5+/-0.08 ml/min, which was not significantly different from that in the untreated control rats, of 0.8+/-0.14 ml/min. As expected, the right intact kidneys responded with an increase in GFR to about 2 ml/min. Further effects that were similar in the damaged kidneys of the furosemide-treated and untreated animals were a decrease in potassium secretion and in the urine concentration ability; the urine osmolality in the diseased left kidneys was thus 1000-1500 mOsm/kg, as against over 2000 mOsm/kg in the right, intact kidneys. The function of the individual nephrons in terms of such variables as single nephron filtration rate, fractional fluid reabsorption and tubular and vascular hydrostatic pressures remained unaltered, however. Hence, the severe reduction in whole kidney GFR appeared to be due to a loss of nephrons rather than to an equal decrease in each individual nephron. It is also clear that furosemide did not improve the long-term outcome of acute postischaemic renal failure.
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Affiliation(s)
- O Källskog
- Department Medical Cell Biology, BMC, Uppsala University, Sweden
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Abstract
The aim of this study was to investigate whether the increased diuresis in consequence of hypothermia is due to a depression of the hypothalamic release of antidiuretic hormone (ADH). The plasma concentration of antidiuretic hormone and the effect of intravenous (i.v.) administration of 65 ng kg-1 desmopressin (selective V2-receptor agonist) were determined in the anaesthetized rat. In spite of a 50% (P < 0.001) decrease in glomerular filtration rate, urine flow increased sixfold (P < 0.01) and urine sodium excretion increased sevenfold (P < 0.05), whereas urine osmolality decreased (P < 0.001). At the same time plasma antidiuretic hormone decreased from 7.5 +/- 1.1 to 3.8 +/- 0.4 pg mL-1 (P = 0.01). After injection of desmopressin urine flow was completely restored, whereas urine osmolality and sodium excretion were only partially normalized. Since tubular conservation of water and fractional water reabsorption decreased during hypothermia, the diuresis must have resulted from an augmented loss of water. This is further supported by the fact that osmolal excretion was not influenced either by hypothermia or by desmopressin. It is concluded that the diuresis in consequence to hypothermia is due both to a decrease in the release of ADH and to a reduction of renal medullary hypertonicity.
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Affiliation(s)
- M Broman
- Department of Physiology and Medical Biophysics, BMC, University of Uppsala, Sweden
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Silvennoinen R, Jaaskelainen T, Nygren K, Hiltunen J, Parkkinen J. Temporal, Spatial, and Environmental classification of Pine Reflectance Spectra. Environ Sci Technol 1995; 29:1456-1459. [PMID: 22276864 DOI: 10.1021/es00006a005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Abstract
In the acute phase of ischemic renal failure, the severe depression of the glomerular filtration rate (GFR) is due to obstruction of the tubules by cells and cell debris rejected from the proximal tubules, a blockade which can be prevented at least partly, by treatment with osmotic diuretics. The isosthenuria, the second typical sign in ischemic acute renal failure, probably derives from the medullary ischemia that results from an intracapillary trapping of red cells. This, in turn, is suggested to be caused by oxygen-derived free radicals, which via increasing the capillary macromolecular permeability result in a massive extravasation of plasma and hence in hemoconcentration. As expected from this hypothesis, scavengers may ameliorate both the trapping and the consequent medullary ischemia. Unfortunately, however, a therapy using both osmotic diuretics and scavengers fails to improve the long-term outcome. Hemodilution would seem more promising, since it will both prevent the medullary ischemia seen in the acute phase and substantially improve the long-term outcome. At a hematocrit of 0.30, rat kidneys exposed to 45-min ischemia will show a GFR 1 month after the insult of more than 50% of the normal GFR as against 15% in untreated animals.
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Affiliation(s)
- M Wolgast
- Department of Physiology and Medical Biophysics, University of Uppsala, Sweden
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Affiliation(s)
- A Bayati
- Department of Physiology and Medical Biophysics, University of Uppsala, Sweden
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15
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Abstract
Oxygen radicals in postischaemic damages in the kidney: M. Wolgast, A. Bayati, O. Hellberg, O. Källskog, K. Nygren and G. Ojteg, Inst. of Physiology and Medical Biophysics, University of Uppsala, Sweden; Ischemic acute renal failure is characterized by a severe depression of the glomerular filtration rate (GFR), isosthenuria and deficient potassium secretion, whereas the total renal blood flow may remain largely intact. As to these symptoms, it would seem established that the depression of GFR results from an ischaemia-induced augmented aging and hence rejection of tubular cells, which thence blocks the tubular lumen. As expected this blockade can be prevented by osmotic diuretics. The isosthenuria and the deficient potassium excretion, on the other hand, results probably from a medullary ischaemia, the latter due to the action by oxygen-derived free radicals in the sense the subsequent damage to the capillary membrane leads to a massive extravasation of plasma and consequent intracapillary trapping of red cells. In line with this idea, superoxide-dismutase (SOD) or Allopurinol may ameliorate these changes. In the recovery phase of postischaemic renal failure, the most prominent feature is the blocking of the ascending loop of Henle with Tamm/Horsfall-protein which, if not washed-out during the first week, leads to a complete degeneration of the nephron. Unfortunately, the process would seem to be unaffected by treatment with e.g. osmotic diuretics and SOD or Allopurinol.
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Affiliation(s)
- M Wolgast
- Institut of Physiology and Medical Biophysics, University of Uppsala
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Bayati A, Nygren K, Källskog O, Wolgast M. The effect of loop diuretics on the long-term outcome of post-ischaemic acute renal failure in the rat. Acta Physiol Scand 1990; 139:271-9. [PMID: 2368616 DOI: 10.1111/j.1748-1716.1990.tb08924.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The effects of continuous treatment with loop-acting diuretics on the long-term functional and histopathological outcome in kidneys subjected to 45 min of warm ischaemia were studied. One month after the primary damage the inulin clearance in the untreated kidneys was 0.44 +/- 0.05 ml min-1, improving significantly to 0.69 +/- 0.11 ml min-1 in furosemide-treated animals and to 0.75 +/- 0.09 ml min-1 in those treated with piretanide. Urine osmolality increased from 986 +/- 89 mosmol kg-1 in the untreated animals to 1479 +/- 195 mosmol kg-1 in the furosemide-treated ones. At the same time the total area of the outer medulla occupied by Tamm-Horsfall protein cylinders decreased from 7.0 +/- 1.2% in the untreated animals to 3.6 +/- 0.52% in the treated ones. It is concluded that by decreasing the number of nephrons blocked by Tamm-Horsfall cylinders an improvement in the function of ischaemically damaged kidneys can be achieved. This blockade, also called secondary damage, is of critical prognostic importance for the long-term outcome of the ischaemic renal failure. Treatment of the animals with loop diuretics decreased the occurrence of these cylinders, leading to an improvement of kidney function I month after the primary damage, this despite the fact that the primary damage seen in the early recirculation period was not treated specifically.
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Affiliation(s)
- A Bayati
- Department of Physiology and Medical Biophysics, University of Uppsala, Sweden
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Bayati A, Nygren K, Källskog O, Wolgast M. The long-term outcome of post-ischaemic acute renal failure in the rat. II. A histopathological study of the untreated kidney. Acta Physiol Scand 1990; 138:35-47. [PMID: 2309567 DOI: 10.1111/j.1748-1716.1990.tb08810.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Histopathological changes in kidneys subjected to 45 min of isothermic unilateral ischaemia in the acute phase and 1 week and 1 month after primary damage were studied at the electron microscopic level. During the first week after recirculation long homogeneous cylinders, probably consisting of Tamm-Horsfall protein, developed in the medullary parts of the nephron, and after 1 month of recirculation there were two types of nephrons: (1) nephrons with a normal histological appearance and (2) degenerated nephrons. The latter group gave rise to crypts in the outer cortical area. It is hypothesized that the generation of the long Tamm-Horsfall cylinders in the thick ascending limb of the loop of Henle plays an important role in the long-term outcome of the kidney after the primary damage. The persistent blockade caused by these cylinders will lead to precipitation of the ultrafiltrate, resulting in long cell-protein cylinders in the proximal parts of the nephron. This precipitation will proceed in the retrograde direction, reaching the mother glomeruli, eventually leading to total degeneration of the nephron.
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Affiliation(s)
- A Bayati
- Department of Physiology and Medical Biophysics, University of Uppsala, Sweden
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Olsson K, Dahlborn K, Nygren K, Karlberg BE, Andén NE, Eriksson L. Fluid balance and arterial blood pressure during intracarotid infusions of atrial natriuretic peptide (ANP) in water-deprived goats. Acta Physiol Scand 1989; 137:249-57. [PMID: 2533454 DOI: 10.1111/j.1748-1716.1989.tb08746.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The aim of this study was to investigate if atrial natriuretic peptide (ANP) plays a role in the control of water balance in goats and whether ANP affects the increase in mean arterial blood pressure (MAP) which accompanies drinking in water-deprived animals. Bilateral intracarotid infusions were made in female adult goats deprived of water for 48 h. ANP (1.5 micrograms min-1, n = 5, or 4.75 micrograms min-1, n = 5) was infused for 40 min. In control experiments isotonic saline (n = 7) was infused. The goats got access to water 35 min after the start of the infusions. During saline infusions they drank 2.9 +/- 0.4 litres, during the low dose of ANP 1.9 +/- 0.6 litres (n.s. vs saline), and during the high dose of ANP 0.6 +/- 0.2 litres (P less than 0.01 vs saline). Plasma vasopressin concentration did not change during saline infusions until after drinking, when it decreased. The vasopressin concentration increased in one goat after infusion of the low dose of ANP and in two goats after the high dose of ANP. The low dose of ANP caused no change in MAP in four goats, but MAP dropped in the one in which vasopressin concentration increased. MAP fell in all goats infused with the high dose (P less than 0.01), with the largest changes occurring in animals showing increased vasopressin concentration. During the act of drinking a temporary increase of MAP was observed when saline or the low dose of ANP was infused, but this response was attenuated during infusions of the high dose.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K Olsson
- Department of Animal Physiology, Swedish University of Agricultural Sciences, Uppsala
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Abstract
The permeability characteristics of the peritubular capillary membrane in the rat kidney were investigated on the basis of the transport of hippuran, inulin, myoglobin, horseradish peroxidase, albumin, and gamma-globulin from peritubular capillary blood to renal hilar lymph. Data obtained in a previous investigation on single-nephron plasma flow, filtration fraction, net driving force, and fluid reabsorption along the peritubular capillary were also used. The data were analyzed in a computer-based model taking into account the transport both by diffusion and by convection. The results show that the membrane contains a few large pores through which the plasma proteins leak out into the renal interstitium and a system of several smaller pores responsible for the fluid reabsorption. The mean equivalent radius of the large pores was estimated from the larger molecular probes to be approximately 180 A (range 150-225 A), and the corresponding total pore area over pore length was estimated at 3 X 10(-4) cm (range 6 X 10(-4) to 1 X 10(-4) cm). The small-pore system was analyzed from the transport of hippuran, inulin, and myoglobin and from fluid reabsorption and showed a pore radius of somewhat below 20 A and pore areas over pore length of 50 cm. Here, the fluid reabsorption and the transport of hippuran turned out to be a sensitive marker of the pore area and the transport of inulin and myoglobin of the pore radius.
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Abstract
This paper describes the preparation of charged and uncharged protein molecular probes for study of the permselectivity of renal capillaries. Horse heart myoglobin was used as a neutral myoglobin. Since it contained several fractions with different isoelectric points, it was purified by fast protein liquid chromatography (FPLC). To obtain a negatively charged myoglobin, the original horse heart myoglobin was treated with cyanate, resulting in net charge of -5.7 +/- 0.3 at physiological pH (mean +/- SEM). The charge was determined from the Donnan potential which develops over a semipermeable membrane separating the inside solution in which the protein was dissolved from a surrounding bath of equal ionic strength. Sperm whale myoglobin was similarly purified by FPLC and used as a positively (+1.7 +/- 0.2) charged isomer. Horseradish peroxidase (HRP) was purified by means of gel and ion-exchange chromatography and found to be neutral at physiological pH. Negatively charged (-14.0 +/- 0.5) HRP was obtained by succinylation. Two isomers of lactate dehyrogenase (LDH) were used, namely the slightly positive (+2) LDH-M4 and the strongly negative (-19) LDH-H4. These isomers, which occur naturally, did not require further purification. The Stokes-Einstein radii, as measured by gel chromatography, of inulin, myoglobin, HRP and LDH were 11, 17.5, 32 and 46 A, respectively. The chemical modifications did not alter the Stokes-Einstein radii. In biological studies on rat kidneys samples of both plasma and renal hilar lymph were found to contain radioactive low molecular weight degradation products in addition to the intact proteins. This necessitated separation of all individual samples on small Sephadex columns prior to analysis.
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Ojteg G, Nygren K, Wolgast M. Permeability of renal capillaries. II. Transport of neutral and charged protein molecular probes. Acta Physiol Scand 1987; 129:287-94. [PMID: 3577815 DOI: 10.1111/j.1748-1716.1987.tb08071.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The permselectivity of the renal capillaries was investigated from the transport of a series of molecular probes: inulin, positive (+2, net charge at pH 7.4), neutral (0), and negative (-6) myoglobin, neutral (0) and negative (-14) horseradish peroxidase (HRP) and two isomers of lactate dehydrogenase (LDH), namely the positively charged (+2) LDH-M4 and the negatively charged (-19) LDH-H4. The determination of the concentration of tracer proteins necessitated gel separation of both plasma and renal hilar lymph. The reason for this is that the proteins, after filtration, will be reabsorbed and degraded by the proximal tubular cells into small molecular compounds (amino acids), which will return to both the renal interstitium and systemic plasma. Even if this degradation is of low degree, as for high-molecular-weight proteins, separation is still required, since the relative lymph concentration (plasma concentration put at 1) is also low, that is, even small amounts of low molecular compounds will distort the relative lymph concentration obtained. The transport from plasma to renal hilar lymph of the tracer molecules fell with increasing Stokes-Einstein radius. The relative lymph concentration of the 11 A inulin was 1.06 +/- 0.03 (mean +/- SEM), of the neutral 17.5 A myoglobin 0.76 +/- 0.05, of the neutral 32 A HRP 0.32 +/- 0.02 and of the neutral 46 A LDH 0.12 +/- 0.01. The data are compatible with a two-pore system. The negative tracer molecules were in general proportionally more restricted than the neutral (or positive) moieties (P less than 0.001) thus suggesting a negatively charged peritubular capillary membrane.(ABSTRACT TRUNCATED AT 250 WORDS)
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Nygren K, Hermansson A, Stenback L. [Vansbro, Dalarna: chaotic year for nurses. Interview by Janne Berglund]. Vardfacket 1985; 9:6-8. [PMID: 3853434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Wolgast M, Karlberg L, Källskog O, Norlén BJ, Nygren K, Ojteg G. Hemodynamic alterations in ischaemic acute renal failure. Nephron Clin Pract 1982; 31:301-3. [PMID: 7177266 DOI: 10.1159/000182671] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
It is concluded that the condition of 'acute renal failure' starts in the first minutes after restoration of the circulation, following the ischemic period. The aggregation of red blood cells in the renal medulla with the subsequent cessation of medullary blood flow represents an important factor causing both the reduced urinary concentrating ability and the depressed urinary potassium concentration. The persisting medullary ischemia leads to cellular swelling and eventually to cell necrosis, which in turn results in a mechanical obstruction of the tubular lumen in the region of the loops of Henle and the medullary collecting ducts. In contrast, the anuria which is evident weeks after the primary damage, seems to be caused by the release of vasoconstrictor principles, whose origin is unclear, but it seems not to be mediated via the renal nerves, since the same symptoms are found in transplanted kidneys. Therapeutic endeavors using heparin, saline expansion and mannitol to improve the rheological characteristics of the blood seems to be of limited value. Infusion of hyperoncotic albumin during the ischemic period, however, seems to be of some benefit, since glomerular filtration is better preserved. The addition of ATP and magnesium, glucose or adjustment of the acid base status with buffers has not been encouraging in the present models, in which glomerular filtration rate is reduced to only a few percent of control.
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Karlberg L, Källskog O, Nygren K, Wolgast M. Erythrocyte and albumin distribution in the kidney following warm ischemia. A study in rats. Scand J Urol Nephrol 1982; 16:173-7. [PMID: 7123169 DOI: 10.3109/00365598209179749] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A dark zone of probably stagnant erythrocytes, localised primarily to the inner stripe of the outer medulla, is always found in acute renal failure caused by clamping of the renal artery for 45 min. To test the possible accumulation of red cells, the regional renal red cell content was investigated with 51Cr labelled red cells injected before, during and 10 min after the recirculation. Analyses were made of the volumes of (1) cells remaining from the period of clamping, (2) cells aggregated 0--10 min after recirculation and (3) cells still circulating 10--20 min after recirculation. In the inner stripe the total red cell volume was 21.8 +/- 2.2 microliter . 100 mg-1 (control value 9.3 +/- 0.6), where 26% remained from the period of clamping, 46% had accumulated 0--10 min after recirculation, and only 28% had entered the region 10--20 min after recirculation. The same pattern of response, though less pronounced, was also found in the inner zone. In the cortex the total red cell volume was 6.3 +/- 1.2 microliter . 100 mg-1 (control value 4.4 +/- 0.3), where 24% remained from the period of clamping, 32% were accumulated and 44% remained circulating. The plasma volume as investigated from 131I-labelled albumin was markedly increased in all zones, probably due to extravasation of the tracer. It is suggested that red cell accumulation plays an important role for the medullary ischemia found in ischemic acute renal failure.
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Abstract
The renal interstitial space analyzed as "inulin space" comprises about 13% in the rat. The Starling forces of this compartment are governed by the balance between tubular and capillary fluid transport and also by the leakage of plasma proteins from the blood side. Protein transport will occur in a large-pore system in the peritubular capillary membrane. During control antidiuresis, the interstitial hydrostatic pressure is 2-4 mmHg. The colloid osmotic pressure shows a larger variability but is generally about 5 mmHg. During conditions of depressed capillary reabsorption but unchanged tubular reabsorption, as in saline expansion, the interstitial hydrostatic pressure rises 3-4 times, whereas the colloid osmotic pressure will show a steep fall resulting from the increased fluid entry and unchanged protein transport. The interstitial volume increases only slightly, since it is compressed by the expanding tubules. The influence of interstitial physical forces on tubular transport remains unclear, mainly due to the inaccessibility of the lateral interspaces to direct measurement of relevant parameters.
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Abstract
By exposure measurements in an alcohol-water mixture simulating breast tissue, the absorbed dose, and dose distribution in the breast at the radiation qualities commonly used in mammary radiography have been calculated. The absorbed doses for different recording media have been compared at those radiation qualities which result in similar image qualities in the different recording media.
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