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  • 1
    Electronic Resource
    Electronic Resource
    Observations on the limnology and primary production of a small man-made lake in the West African savanna (1973)
    Oxford, UK : Blackwell Publishing Ltd
    Freshwater biology 3 (1973), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: 1. The results of limnological studies on a small, 35-ha, triangular man-made lake and a small adjacent fish pond in the coastal savanna of Ghana are described.2. The lake, which has a renewal time of approximately 0.96 years, is subject to large, predictable seasonal changes. Water volume and surface area rapidly reach maximum values in the wet season from April to June despite the low runoff values which average only 1.2% of the precipitation. Minimum values occur in the dry season when up to 76% of the lake area may be exposed. Most of the water is lost by evaporation which may amount to 193 cm annually.3. The annual cycle in water temperature follows that in solar radiation with peaks towards the end of the dry season in March to April and deep troughs in the wet season from April to June. During the dry season the water column is characterized by greater stability, a higher degree of stratification, and a much higher amplitude of diurnal temperature change (4-5°C) than in the wet season (1°C). Isothermal conditions tend to be approached nocturnally and even during the day in the wet season.4. The ionic content of the water is low and dominated by bicarbonate, sodium, silica and iron. During the wet season flood water results in a decline in conductivity from 214 to 30 μmhos/cm2, a decrease in pH and transparency, and an increase in oxidizable organic material. Except for the conductivity these values return to normal in about 6 weeks as a result of rapid decomposition of allochthonous materials.5. The oxygen pulse is strong and photosynthetic activity by phytoplankton high during the dry season whereas in the wet season the converse is true. As a result of the low concentration of organic carbon (0.10–0.35%) in the sediments their oxygen demands are low. Consequently, dissolved oxygen values near the sediment are relatively high and oxygen stratification poorly-developed. Most of the organic carbon appears to be recycled in the water column rather than in the sediments as is generally the case in tropical ecosystems.6. Rooted vegetation became permanently established in the fish pond but not i n the lake itself. Emergent and floating vegetation which grows profusely in the draw-down area in the wet season is for the most part exported from the system by wind and biological agencies and, therefore, contributes little to the energy and mineral budgets of the lake. Primary production in the water column is mainly by Myxophyceae and Bacillariophyceae and is low during the dry season (1.35 gC/m2/day) and very low in the wet season. Possible reasons for the low level of primary production are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2427.1973.tb00079.x
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  • 2
    Electronic Resource
    Electronic Resource
    Production of Erythropoietin by Liver Cells in Vivo and in Vitro (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 718 (1994), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1994.tb55703.x
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  • 3
    Electronic Resource
    Electronic Resource
    Erythropoietin-producing Cells in Transgenic Mice Expressing SV40 Large T Antigen Directed by Erythropoietin Control Sequences (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 718 (1994), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1994.tb55739.x
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  • 4
    Electronic Resource
    Electronic Resource
    Analysis of Cis-acting Sequences Required for Operation of the Erythropoietin 3’Enhancer in Different Cell Lines (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 718 (1994), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1994.tb55701.x
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  • 5
    Electronic Resource
    Electronic Resource
    UK Prospective Diabetes Study (UKPDS) 14: association of angiotensin-converting enzyme insertion/deletion polymorphism with myocardial infarction in NIDDM (1995)
    Springer
    Diabetologia 38 (1995), S. 948-952 
    Details
    ISSN: 1432-0428
    Keywords: Key words Non-insulin-dependent diabetes mellitus ; myocardial infarction ; angiotensin-converting enzyme ; genetics ; risk factors.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The deletion allele of the insertion/deletion polymorphism of the angiotensin-converting enzyme gene has been suggested to be an independent risk factor for myocardial infarction, particularly in subjects judged to be “low-risk” by the criteria of lipid status and body mass index. In a prospective, matched case-control study, we have investigated the role of this polymorphism as a risk factor for myocardial infarction in 173 newly-diagnosed British Caucasian non-insulin-dependent diabetic subjects taken from the United Kingdom Prospective Diabetes Study who subsequently developed myocardial infarction and 297 control subjects from the same study population matched for known cardiovascular risk factors including age at diagnosis of diabetes, gender, blood pressure, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride and smoking habit. A trend towards increased risk conferred by homozygosity for the deletion allele was observed in cases (odds ratio 1.63, p = 0.09). When the population was stratified according to the matched risk factors, the deletion allele was associated with myocardial infarction in those with low plasma low-density lipoprotein cholesterol (odds ratio 3.67, p = 0.002), or low triglyceride (odds ratio 3.14, p = 0.005). The strongest association of the deletion allele with myocardial infarction was observed in subjects with both low low-density lipoprotein cholesterol and low triglyceride levels (odds ratio 9.0, p 〈 0.001). These results show that the deletion allele is a risk factor for myocardial infarction in non-insulin-dependent diabetic patients who have a favourable lipid profile. [Diabetologia (1995) 38: 948–952]
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00400584
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  • 6
    Electronic Resource
    Electronic Resource
    UK Prospective Diabetes Study (UKPDS) 14: association of angiotensin-converting enzyme insertion/deletion polymorphism with myocardial infarction in NIDDM (1995)
    Springer
    Diabetologia 38 (1995), S. 948-952 
    Details
    ISSN: 1432-0428
    Keywords: Non-insulin-dependent diabetes mellitus ; myocardial infarction ; angiotensin-converting enzyme ; genetics ; risk factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The deletion allele of the insertion/deletion polymorphism of the angiotensin-converting enzyme gene has been suggested to be an independent risk factor for myocardial infarction, particularly in subjects judged to be “low-risk” by the criteria of lipid status and body mass index. In a prospective, matched case-control study, we have investigated the role of this polymorphism as a risk factor for myocardial infarction in 173 newly-diagnosed British Caucasian non-insulin-dependent diabetic subjects taken from the United Kingdom Prospective Diabetes Study who subsequently developed myocardial infarction and 297 control subjects from the same study population matched for known cardiovascular risk factors including age at diagnosis of diabetes, gender, blood pressure, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride and smoking habit. A trend towards increased risk conferred by homozygosity for the deletion allele was observed in cases (odds ratio 1.63, p=0.09). When the population was stratified according to the matched risk factors, the deletion allele was associated with myocardial infarction in those with low plasma low-density lipoprotein cholesterol (odds ratio 3.67, p=0.002), or low triglyceride (odds ratio 3.14, p=0.005). The strongest association of the deletion allele with myocardial infarction was observed in subjects with both low low-density lipoprotein cholesterol and low triglyceride levels (odds ratio 9.0, p〈0.001). These results show that the deletion allele is a risk factor for myocardial infarction in non-insulin-dependent diabetic patients who have a favourable lipid profile.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00400584
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  • 7
    Electronic Resource
    Electronic Resource
    The quality of function of renal allografts is associated with donor age (1995)
    Springer
    Transplant international 8 (1995), S. 221-225 
    Details
    ISSN: 1432-2277
    Keywords: Donor age, renal function ; Kidney function, donor age ; Age donor, renal function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The quality of renal allograft function was assessed by prospective measurement of creatinine clearance at 1 year (n=197) and at 3 years (n=115) after cadaveric renal transplantation in a cohort of 268 patients treated with triple therapy immunosuppression. Donor age (P〈0.0012) and recipient age (P〈0.01) were independently associated with creatinine clearance both at 1 and at 3 years. In patients with donor age above 50 years and recipient age above 45 years, the mean creatinine clearance was 32.7 (SD 10.4) ml/min (n=27). When the donor age was below 30 years and recipient age below 45 years, the mean creatinine clearance was 55.6 (SD 14.4) ml/min (n=47, P〈0.001). However, in these patients there was no significant association between graft function and many of the factors known to influence graft survival, such as HLA matching, sensitisation of the recipient, and the occurrence of rejection. In conclusion, the quality of renal allograft function declined with increasing donor and recipient age in our patients, whilst immunological factors were not significantly associated with function in surviving grafts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336541
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  • 8
    Electronic Resource
    Electronic Resource
    Triple therapy immunosuppression in cadaveric renal transplantation (1990)
    Springer
    Transplant international 3 (1990), S. 26-31 
    Details
    ISSN: 1432-2277
    Keywords: Immunosuppression, triple therapy, kidneys ; Cyclosporin, in triple therapy ; Azathioprine, in triple therapy ; Kidney transplantation, triple therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract One hundred and ninety-two patients received 200 consecutive cadaver renal transplants (158 first and 42 regrafts) and were treated with triple therapy immunosuppression consisting of low-dose cyclosporin, azathioprine and prednisolone. One-year patient and graft survival rates were 95% and 82%, respectively. Against this low rate of graft loss, the proportion of rejection-free patients in the first 3 months was strongly related to matching for HLA-DR (P〈0.01), although HLA-DR matching was not associated with improved graft survival. More grafts were lost to nonimmunological causes than to rejection, and these losses fell into three main categories, namely, losses in elderly and diabetic patients and losses due to renal vascular thrombosis. Thus, triple therapy immunosuppression appears to offer effective immunosuppression, resulting in good graft and patient survival, especially in highly sensitised patients or patients receiving regrafts. There are relatively few serious adverse effects, although elderly and diabetic patients experienced significant morbidity and mortality after transplantation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00333199
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  • 9
    Electronic Resource
    Electronic Resource
    Oxygen-dependent expression of the erythropoietin gene in rat hepatocytes in vitro (1993)
    Springer
    Pflügers Archiv 423 (1993), S. 356-364 
    Details
    ISSN: 1432-2013
    Keywords: Erythropoietin ; Hepatocytes ; Rat ; In vitro ; Hypoxia ; Signalling ; mRNA ; RNase protection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Since in juvenile rats the liver is the predominant site of erythropoietin (EPO) gene expression, we have used primary cultures of juvenile rat hepatocytes to establish an in vitro system for investigation of oxygen-dependent EPO formation. When isolated hepatocytes were incubated at reduced oxygen tensions for 18–48 h, we found increased secretion of EPO protein and elevated levels of EPO mRNA, as determined by RNase protection. This increase was maximal at 3% O2, where EPO mRNA levels after 18 h were approximately 15fold higher than at 20% O2. The increase in EPO mRNA at low oxygen tensions was specific insofar as [3H]uridine incorporation, as a measure of total RNA synthesis, was reduced by approximately 50% at 3% O2, and it appeared to involve gene transcription since it was abolished in the presence of actinomycin D (35 μM). Significant increases in EPO mRNA were also observed in cells kept at 20% oxygen in the presence of cobalt chloride (50 μM) and nickel chloride (400 μM), but EPO mRNA levels achieved under these conditions were less than 7% of those in cells incubated at 3% oxygen. No increase in EPO mRNA levels was observed in cultures incubated at 20% O2 in the presence of cyclic dibutyrylAMP (10 μM-3 mM), cyclic 8-bromoGMP (10 μM1 mM), cyclohexyladenosine (1 μM), 5′-N-ethylcarboxamidoadenosine (1 μM) and phorbol 12-myristate 13acetate (3 nM). In the presence of 10% carbon monoxide, used to block haem proteins in their oxy conformation, EPO mRNA levels in hepatocytes incubated at low oxygen tensions were reduced to 63%. Taken together, these findings indicate that oxygen-dependent control of the EPO gene in hepatocytes operates via intrinsic cellular oxygen-sensing mechanisms. Their signal transduction does not seem to occur via classical “second-messenger” pathways. A haem protein may be involved in oxygen sensing, but no conclusive evidence was obtained as to whether it is essential.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374928
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