bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of specialist and generalist species along spatial gradients of habitat disturbance and fragmentation
Authors: Devictor Vincent , Julliard Romain , Jiguet Frédéric
Published: March 2008

In this paper, we tested whether the spatial distribution of a given species in more or less fragmented and disturbed landscapes depends on the species habitat specialization. We studied 891 spatial replicates from the French Breeding Bird Survey (FBBS) monitored at least two years during 2001–2005, and two independent landscape databases measuring respectively landscape fragmentation and recent landscape disturbance on each FBBS replicate. We used a continuous habitat specialization index for the 105 most common bird species monitored by the FBBS. We further modelled the spatial variation in abundance of each species according to fragmentation and disturbance across FBBS replicates, accounting for habitat differences and spatial trends. We then tested whether more or less specialized species responded to landscape fragmentation and disturbance. We found that the more specialist a species, the more negative its spatial response to landscape fragmentation and disturbance. Although there was a very high variation around these tendencies indicating that there are many other drivers of species distribution, our results suggest that measuring specialization may be helpful in predicting which species are likely to thrive in human degraded landscapes. We also emphasize the need to consider both positive and negative species responses when assessing consequences of habitat change in communities.
On the importance of the negative selection effect for the relationship between biodiversity and ecosystem functioning
Authors: Jiang Lin , Pu Zhichao , Nemergut Diana R.
Published: March 2008

Much of our knowledge on biodiversity and ecosystem functioning comes from studies examining the effects of biodiversity on biomass production within a trophic group. A large number of these studies have found that increasing biodiversity tends to increase biomass production, leading many ecologists to believe that there exists a general positive relationship between biodiversity and ecosystem functioning. Here we argue that such a positive relationship may not be general, particularly for ecosystem functions other than biomass. Our argument centers on the potential importance of the negative selection effect, which operates where competitively dominant species do not contribute significantly to the function of interest. We suggest that negative selection effects may be potentially common for non‐biomass functions, for which species competitive ability may often be a poor indictor of its functional impact. We conclude that diverse (positive, negative, and neutral) BEF relationships are possible for non‐biomass functions and that for a particular function, the exact form of the BEF relationship may depend on how species functional impacts relate to their competitive abilities in the community.
Does asymmetric specialization differ between mutualistic and trophic networks?
Authors: Thébault Elisa , Fontaine Colin
Published: March 2008

Recently, plant–pollinator networks have been found to be highly structured in a nested pattern in which specialists interact with generalist species. This structure is often assumed to be particular to mutualistic interactions in opposition to the compartmentalized pattern expected for antagonistic networks. We investigated the presence of asymmetric specialization in a data set assembled from the literature of 20 highly resolved plant–insect herbivore networks and compared them with 24 plant–pollinator networks. Our results indicate that these two types of networks differ, but not in the way it is generally assumed. Asymmetric specialization is present in plant–herbivore networks even if it appears less frequently than in plant–pollinator networks. Indeed, mean and median percentages of species showing asymmetric specialisation in herbivory webs are 33% and 14% respectively, compared to 57% and 60% in pollination webs. Furthermore, the amount of asymmetry is linked with species diversity and not to connectance in plant‐pollinator networks whereas the opposite pattern is found in plant–herbivore networks. Our results offer promising perspectives for understanding both the mechanisms that structure ecological communities and their impact on community dynamics depending on the type of interaction.
A deletion in the bone morphogenetic protein 15 gene causes sterility and increased prolificacy in Rasa Aragonesa sheep
Authors: Martinez‐Royo A. , Jurado J. J. , Smulders J. P. , Martí J. I. , Alabart J. L. , Roche A. , Fantova E. , Bodin L. , Mulsant P. , Serrano M. , Folch J. , Calvo J. H.
Published: March 2008

Bone morphogenetic protein 15 (BMP15) is a member of the transforming growth factor beta superfamily, is specifically expressed in oocytes and is essential for sheep prolificacy. Reported mutations in this gene cause increased ovulation rate and infertility in a dosage‐sensitive manner. In this work, a new naturally occurring mutation in the BMP15 gene from the ovine Rasa Aragonesa breed is described. This mutation is a deletion of 17 bp that leads to an altered amino acid sequence and introduces a premature stop codon in the protein. Highly significant associations (P < 0.0001) were found between the estimated breeding value for prolificacy and the genotype of BMP15 in Rasa Aragonesa animals with high and low breeding values for this trait. As for other mutations in BMP15, this new mutation is associated with increased prolificacy and sterility in heterozygous and homozygous ewes respectively.
Innocuous Nature of the Sickling (Pseudosickling) Phenomenon in Deer
Authors: Whitten C. F.
Published: March 2008

1. Sickle‐shaped deer cells have a normal life span because they are non‐fragile, and they do not obstruct blood vessels because they are small and pliable. Thus, the presence of sickle‐shaped cells in deer is innocuous. These findings have relevance to the sickling phenomenon in humans in that they emphasize the importance of the physical properties of sickled cells, exclusive of shape, in the pathogenesis of sickle cell anaemia.

2. The data in this study in conjunction with previous observations in the literature indicate that there are five basic differences between the sickling phenomenon in deer and humans, (a) The haemoglobin of deer differs from human sickle haemoglobin in composition and in electrophoretic behaviour, (b) The formation of sickle‐shaped deer cells can be induced by oxygenation (which blows off carbon dioxide and induces a pH change), whereas human cells sickle when de‐oxygenated, (c) The internal structure of deer sickle‐shaped cells is probably that of a gel instead of the tactoid formation found in human cells, (d) Sickle‐shaped cells of deer are non‐fragile and pliable whereas human sickle cells are fragile and rigid, (e) The presence of sickle‐shaped cells in humans produces a disease state, whereas their presence in deer is innocuous. Since the shape of the cells is the only property that is similar in deer and human sickling, it is more appropriate to designate the phenomenon in deer as ‘pseudosickling’.
Unidentified Inclusions in Haemopoietic Cells, Congenital Atresia of the Bile Ducts and Livedo Reticularis in an Infant:? A New Syndrome
Authors: Smith H.
Published: March 2008

An infant is described with congenital atresia of the bile ducts, livedo reticularis of the skin and unidentified inclusions in haemopoietic cells. In Romanowsky stained films the inclusions occurred as round to oval, amorphous, green or grey‐green coloured bodies in a proportion of the cells, especially granulocytes and monocytes. Masses of material with some similarity to that in the inclusions lay free in the bone marrow. Electron‐microscopy and cytochemical procedures have failed to give positive identification though the material is likely to be a protein other than DNA or RNA. The leucocyte anomaly does not appear to be a result of the livedo reticularis, the biliary obstruction or the jaundice or liver damage consequent on this. It is suggested that the occurrence together of the leucocyte anomaly, congenital atresia of the bile ducts and livedo reticularis of the skin may constitute a syndrome.
Relationship between Membrane Function and Permeability
Authors: Cohen Phin
Published: March 2008

As the osmolarity of the medium decreases, ‘platelet factor‐3’ (PF‐3) availability increases in erythrocyte as well as platelet suspensions. Associated with this is a parallel increase in PF‐3 activity of the cell‐free supernatant.

Addition of glycerol to platelet or erythrocyte suspensions enhances PF‐3 availability of the cell suspensions but not the cell‐free supernatants. It is proposed that glycerol influx alters the orientation or binding of membrane thromboplastic phospholipids, thereby facilitating their reactivity in the PF‐3 assay.
Red Cell Survival and Splenic Accumulation of Radiochromium in Liver Cirrhosis with Splenomegaly
Authors: Subhiyah B. W. , Al‐Hindawi A. Y.
Published: March 2008

Red cell survival was studied in 22 cirrhotic patients and in four healthy volunteers by the 51Cr method.

Seven patients (32 per cent) showed a definite reduction in the apparent half survival time (51Cr T4 below 20 days). Eight patients (36 per cent) showed a borderline reduction (51Cr T4 20–24 days). Seven patients (32 per cent) showed a normal 51Cr T4 of 25 days or more. All four controls had 51Cr T4 of 25 days or more.

Surface counting over the spleen showed excess spleen counts more marked in those patients with a shorter red cell life span.
Comparisons of Fibrinolysis and Blood Coagulation in Melanesians and Caucasians
Authors: Booth P. B. , MacGregor A.
Published: March 2008

Investigations carried out in Port Moresby, Territory of Papua and New Guinea, on blood coagulation and fibrinolysis are described.

Significant differences (P < 0.01) were found when comparing Melanesians with Caucasians, in that the former show decreased plasmin inhibition, increased and accelerated plasminogen activation and prolonged prothrombin times. Total plasminogen levels are similar in the two ethnic groups compared.

The possible roles of liver disease and vitamin K deficiency in the causation of prolonged prothrombin times in Melanesians merit further study.

It is concluded from the results that compared to Caucasian males resident in the Tropics, Melanesian males have a less labile or more potent plasminogen activator system, and also a relative lack of anti‐plasmin. These differences might account for the increased incidence of hyperplasminaemia in the indigenous population, and possibly are relevant to their comparative freedom from atheromatous and thrombo‐embolic occlusive vascular disease.
Thyroglobulin measurement before rhTSH‐aided 131I ablation in detecting metastases from differentiated thyroid carcinoma
Authors: Giovanella Luca , Ceriani Luca , Suriano Sergio , Ghelfo Antonella , Maffioli Marco
Published: March 2008

Aim  Thyroidectomy followed by administration of large activities of 131‐iodine (131I) is the treatment of choice for differentiated thyroid carcinoma (DTC). The serum thyroglobulin (Tg) measurement during hypothyroidism (offT4‐Tg), just before radioiodine thyroid ablation, has proved to be effective for predicting persistent/recurrent disease. However, the Tg measurement cannot be used as a corresponding value for pre‐ablative offT4‐Tg when recombinant human TSH (rhTSH) is used as stimulus before treatment. The present study was undertaken to evaluate if post‐thyroidectomy Tg values, measured before rhTSH‐stimulated radioiodine ablation is of prognostic value in patients affected by DTC.

Methods  We enrolled 126 patients with DTC submitted to total thyroidectomy. T4 treatment was started just after surgery to suppress TSH levels and Tg levels (onT4‐Tg) were measured just before rhTSH‐aided thyroid ablation by 131I (3700 MBq). Neck radioiodine uptake (RAIU) was measured just before ablation and a post‐treatment whole body scan (PT‐WBS) was performed.

Results  A significant relationship was found between thyroid remnants’ RAIU and onT4‐Tg levels (P < 0·001). The 1·10 ng/ml onT4‐Tg threshold selected by ROC curve analysis identifies patients with positive PT‐WBS with 83·3% sensitivity, 65·7% specificity, 44·5% positive predictive value (PPV) and 93·6% negative predictive value (NPV). The 0·65 ng/ml cut‐off level recognizes metastatic patients with 82·9% sensitivity, 55·2% specificity, 43·3% PPV and 97·8% NPV when compared with 12 months restaging results. Among 63 patients with initially undetectable onT4‐Tg (i.e. ≤ 0·2 ng/ml) none had positive PT‐WBS nor DTC relapse at 12‐month restaging (NPV 100%).

Conclusions  Based on our data we conclude that pre‐ablative onT4‐Tg is a prognostic marker and should be used instead of pre‐ablative TSH‐stimulated Tg measurement when rhTSH‐aided radioiodine ablation is done.
Increased serum advanced glycation end‐products is a distinct finding in lean women with polycystic ovary syndrome (PCOS)
Authors: Diamanti‐Kandarakis Evanthia , Katsikis Ilias , Piperi Christina , Kandaraki Eleni , Piouka Athanasia , Papavassiliou Athanasios G. , Panidis Dimitrios
Published: March 2008

Background  Nonenzymatic advanced glycation and oxidation end‐products, advanced glycation end‐products (AGEs), impart a potent impact on vessels and other tissues in diabetic state and in euglycaemic conditions with increased oxidative stress.

Insulin resistant (IR) polycystic ovary syndrome (PCOS) women, have elevated serum AGEs, increased receptor (RAGE) expression, and increased deposition with differential localization in the polycystic ovarian tissue (theca and granulosa) compared to normal.

Objective  To determine whether the raised AGE levels in noninsulin resistant women with PCOS is a distinct finding compared with those presenting the isolated components of the syndrome and among PCOS subphenotypes. Noninsulin resistant women were selected in order to show that serum AGEs are elevated in PCOS independently of the presence of IR.

Design  Clinical trial.

Patients  One hundred and ninety‐three age‐ and BMI‐matched young lean noninsulin resistant women were studied. Among them, 100 women were diagnosed with PCOS according to Rotterdam criteria, and divided to subphenotypes (hyperandrogenaemia with or without PCO morphology and with or without anovulation). Sixty‐eight women with the isolated components of the PCOS phenotype were also studied along with 25 healthy women.

Measurements  Serum AGE levels, metabolic, hormonal profiles and intravaginal ultrasound were determined in all subjects.

Results  The studied population did not differ in BMI, fasting insulin concentration, waist : hip and glucose : insulin ratios. PCOS women exhibited statistically higher AGEs levels (7·96 ± 1·87 U/ml, P < 0·001) compared with those with isolated hyperandrogenaemia (5·61 ± 0·61 U/ml), anovulation (5·53 ± 1·06 U/ml), US‐PCO morphology (5·26 ± 0·25 U/ml) and controls (5·86 ± 0·89 U/ml).

Conclusions  In PCOS, serum AGEs are distinctly elevated compared with women having the isolated characteristics of the syndrome. No difference was observed between PCOS subphenotypes. As chronic inflammation and increased oxidant stress have been incriminated in the pathophysiology of PCOS, the role of AGEs as inflammatory and oxidant mediators, may be linked with the metabolic and reproductive abnormalities of the syndrome.
Influence of Fasting on Adrenocortical and Pancreatic Islet Response to Glucose Loads in the Obese*
Authors: Kolakowski J. , Pizarro M. A. , Gasparo M. de , Desmecht P. , Harvengt C. , Crabbé J.
Published: March 2008

Abstract The present study was undertaken in an attempt at unravelling the mechanisms involved in alteration of water and electrolyte balance occurring in the obese during fasting and refeeding. After a short control period, 8 obese patients were submitted to total fasting for 7 days, after which they received 200 g glucose orally in 1 dose each morning for 3 consecutive days. The intake of sodium and potassium was kept constant throughout.

Body weight reduction during fasting was far in excess of what could be ascribed to negative caloric balance, on account of fluid and sodium chloride losses. Conversely, carbohydrate refeeding was associated with sodium chloride and water retention.

Urinary sodium excretion exceeded intake during fasting despite the fact that aldosterone secretion rate (ASR) almost doubled, rising from 160 to 280 μg/24 h. After aldosterone was administered i.v. over 3 hours on the penultimate day of fasting, sodium excretion dropped from 62 to 22 mEq/24 h. Cortisol levels in plasma and urine remained normal during fasting.

Unlike what was seen before the fast, glucose administration after 7 days without food resulted in a prompt decrease in sodium (from 34 to 6 mEq/24 h) and potassium (from 48 to 17 mEq/24 h) excretion; ASR and Cortisol values did not change appreciably at that time. Bicarbonate administered in order to correct the acidosis resulting from starvation, failed to reverse the negative sodium balance.

After the fast, a marked deterioration of glucose tolerance was observed, despite an excessive insulin response, since plasma immunoreactive insulin levels at 3 hours were 2.5 times higher than those obtained during the control period.

The hypothesis is raised that the accompanying sodium retention might be, at least in part, due to this increased insulin secretion.
Lipase Activity in the Fat Cake and Aqueous Phase of Adipose Tissue Homogenate of Fed, Fasted and Fasted‐Refed Rats
Authors: Froesch E. R. , Oelz O. , Zapf J. , Waldvogel M.
Published: March 2008

Abstract. 1. Free fatty acid production by the fat cake of adipose tissue was found to be much greater in fasted‐refed than in fasted and fed rats, respectively. Preincubation with adrenalin and dibutyryl cyclic AMP stimulated lipase activities in fasted and fed rats, but not in fasted‐refed rats. Basal lipase activity in the fat cake of fasted‐refed rats was higher than adrenalin or dibutyryl cyclic AMP activated lipase activity of fasted or fed rats. Activation of lipase activity by refeeding lasted for several days.—2. Lipase activity in the aqueous phase of adipose tissue homogenate of all rats was in the same range.—3. Free fatty acid release during the assay of lipase in the fat cake proceeded for a period of up to 120 minutes although not in an entirely linear manner. The ratio of free fatty acids to glycerol release was 2.9. The pH optimum of the reaction was 7.4. NaCl, NaF, protamine and heparin markedly inhibited the lipase reaction. Heparin in the preincubation medium did not reduce the lipase activity in the fat cake.— 4. The very active triglyceride lipase activity of adipose tissue of fasted‐refed rats explains earlier findings showing that intact adipose tissue of fasted‐refed rats exhibits a very high glycerol release. It appears that tissue levels of triglyceride lipase increase during refeeding under the influence of insulin, i.e. at a time when the level of cyclic AMP in the tissue supposedly is low.
Alcohol‐Drugs Interaction in Man: Alcohol and Tolbutamide*
Authors: Carulli N. , Manenti F. , Gallo M. , Salvioli G. F.
Published: March 2008

Abstract. In man tolbutamide was shown to share certain properties with the drugs handled by the hepatic drug‐metabolizing system: its prolonged administration is capable of accelerating its own metabolism; the same effect is obtained by pretreatment with microsomal inducers such as phenobarbital, diphenylhydantoin and diazepam. — Chronic addiction to alcohol produces an enhanced rate of tolbutamide metabolism; on the other hand, prolonged treatment with tolbutamide is able to increase the rate of ethanol oxidation. The existence of a microsomal oxidation of ethanol supports the hypothesis that microsomes may be the site of the interference between alcohol and tolbutamide. — Additional evidence is provided by the observed inhibition of tolbutamide metabolism by ethanol infusion.
Demonstration in Serum of two Physiological Forms of the Human Retinol Binding Protein*
Authors: Peterson P. A.
Published: March 2008

Abstract. The contents of prealbumin, retinol binding protein, and retinol in normal human serum have been estimated. The amounts of prealbumin were, on average, 6 times larger than those of RBP, that is a two‐fold molar excess of prealbumin over RBP. Retinol and RBP were present in about the same molar amounts. Prealbumin occurred in two molecular forms in serum. About half of the prealbumin was bound to RBP (prealbumin‐RBP complex) and half was in free form. In spite of the molar excess of prealbumin, small amounts of free RBP were encountered. The free RBP was isolated from normal serum and displayed about the same characteristics as RBP isolated from the prealbumin‐RBP complex. Some significant differences were noted however. The free RBP had a lower content of retinol and one amino acid residue less of arginine. The contents of prealbumin, RBP, and retinol were also estimated in the sera of patients subjected to chronic haemodialysis. The amounts of prealbumin and retinol were normal or somewhat low whereas the values for RBP were considerably elevated. The size distribution of RBP and retinol in the serum of one of these patients showed that the amount of free RBP was considerably elevated whereas the amount of the prealbumin‐RBP complex was normal. Retinol was apparently associated only with the prealbumin‐RBP complex. Various analyses revealed that RBP, isolated in free form from serum, did not bind to prealbumin in contrast to RBP from the prealbumin‐RBP complex. It is suggested that the free species of RBP, present in serum, represents a transitory form which has fulfilled its physiological role and will rapidly be degraded by the kidney.
The Glucose Uptake of Human Adipose Tissue in Obesity
Authors: Bjöentorp P. , Berchtold P. , Holm J. , Larsson B.
Published: March 2008

Abstract. Radioactivity in adipose tissue triglycerides was followed after giving an intravenous injection of 25 g of glucose with 50 μCi of U‐14C‐glucose to 12 obese and 7 control patients. Seventy‐five minutes after injection the radioactivity could be measured with sufficient precision. Recirculation of label was probably small during this period. Total adipose tissue glucose uptake could therefore be estimated knowing the variation of adipose tissue triglyceride radioactivity in different selected regions, and total body fat, and was found to be only a few per cent of all assimilated glucose in the body. Triglyceride radio‐activity per gram of adipose tissue was similar in obese subjects and controls. Consequently total adipose tissue label was higher in the obese. Triglyceride radioactivity per fat cell correlated positively with fat cell size which in turn correlated positively with plasma insulin concentration. During the two first weeks after injection adipose tissue triglyceride radioactivity increased after which it began to fall in some patients.
Inverse Variations of Plasma Renin Activity and Renin Substrate in Normal Man*
Authors: Rosset E. , Veykat R.
Published: March 2008

Abstract. In the control subject, plasma angiotensin production is a linear function of plasma renin content. Upon incubation of this same plasma in the presence of an excess of homologous renin, angiotensin production is finally limited by the plasma content of renin substrate (PRS). By this method, PRS levels were measured and compared with levels of plasma renin activity (PRA), urinary aldosterone excretion, and sweat sodium and potassium content, in sixteen normal human subjects, aged twenty‐five to thirty years, under three defined metabolic conditions: unrestricted sodium intake, salt depletion, constant sodium intake plus administration of desoxycorticosterone acetate (DOCA).

1) Unrestricted Sodium Intake. In these control subjects, in perfect health, there exist important individual differences in PRS levels. The PRS levels seem to be quite constant for a given subject under a given metabolic condition: the levels remained the same after a four month interval for a given subject.

2) Salt Depletion. Activation of the renin‐angiotensinaldosterone system (RAAS), as shown by an elevation of PRA and of urinary aldosterone excretion, is accompanied by a decrease in PRS levels.

3) Constant Sodium Intake Plus Administration of DOCA. Inactivation of the RAAS, as shown by lowering of PRA and of urinary aldosterone excretion, is accompanied by a marked elevation of PRS levels.

It would appear that, in human control subjects there exists an inverse relationship between PRS and PRA levels.
The Effects of Diphosphonates, Polyphosphates, and Calcitonin on “Immobilisation Osteoporosis” in Rats
Authors: Mühlbauer R. C. , Russell R. G. G. , Williams D. A. , Fleisch H.
Published: March 2008

Abstract. Dichloromethylenediphosphonate (Cl2MDP) and ethane‐l‐hydrory‐l,l‐diphosphonate (EHDP), two compounds related in structure to inorganic pyrophosphate but which contain P—C—P instead of P—O—P bonds, have been shown to inhibit the osteoporosis induced by the immobilisation of the hind limbs of rats. These effects may be due to the ability of diphosphonates to inhibit bone resorption. A polyphosphate and porcine calcitonin inhibited the osteoporosis only slightly. Diphosphonates may prove useful in the therapy of osteoporosis and other diseases in which bone resorption is increased.
Effects of Thyrotrophin‐Releasing Hormone on Plasma Levels of TSH, FSH, LH and GH in Anorexia Nervosa
Authors: Lundberg P. O. , Wålinder J. , Werner I. , Wide L.
Published: March 2008

Abstract. Plasma levels of TSH, FSH and LH were found to be low in cases of anorexia nervosa. Intravenous infusion of synthetic thyrotrophin‐releasing hormone provided a significant rise in TSH without having any effect on FSH or LH. The basal GH levels were normal or raised and no consistent effect of thyrotrophin‐releasing hormone was observed. The results suggest an impaired hypothalamic function as an essential mechanism in anorexia nervosa.
Glucose Metabolism in Normal Human Thyroid Tissue in vitro*
Authors: Otten J. , Dumont J. E.
Published: March 2008

Abstract. Glucose and energy metabolism have been studied in human thyroid tissue in vitro. The pattern of metabolism was found to be similar to the pattern previously described in dog thyroid tissue: very active glycolysis but poorly active pentose phosphate pathway and predominance of mitochondrial versus glycolytic ATP supply. TSH (at low concentrations t 0.1 mU/ml) decreased the oxidation of glucose carbon 1 but enhanced it at high concentrations. Dibutyryl cyclic 3′,5′‐AMP mimicked the effect of low TSH concentrations. At all concentrations TSH enhanced iodide binding to proteins. TSH also enhanced glucose uptake and lactate formation. The action of various transmitters (carbamyl‐choline, epinephrine, prostaglandin E1, serotonin and histamine) on glucose oxidation and iodide binding to proteins was studied. The action of these transmitters demonstrated wide species variation.
Serum Cholesterol Esterification in Liver Disease. Combined Determinations of Lecithin: Cholesterol Acyltransferase and Lipoprotein‐X
Authors: Wengeler H. , Greten H. , Seidel D.
Published: March 2008

Abstract Indirect evidence suggests that lecithin:cholesterol acyltransferase (LCAT) is synthesized in the liver. There are, however, controversial reports in the literature correlating LCAT activity with various forms of liver disease. The purpose of this study was to determine LCAT activity in icteric patients. These were classified not only by the conventional methods, but also with respect to the presence or absence of LP‐X, an abnormal plasma lipoprotein, highly specific for demonstrating or excluding cholestasis. LCAT was measured at different stages of the disease. The patients were divided into 4 groups: I. Hepatitis with cholestasis (LP‐X pos.) [17]; II. Hepatitis without cholestsis (LP‐X neg.) [12]; III. Extra‐hepatic biliary obstruction (LP‐X pos.) [10]; IV. Chronic liver failure (LP‐X neg./pos.) [11]. Compared to normal controls [15], patients from group I had low, group II had normal, group III had normal and group IV had low LCAT activity. In vitro studies clearly excluded the existence of circulating inhibitors of LCAT. From these data it is suggested that the ratio of esterified to unesterified cholesterol in liver disease depends on two factors: LCAT activity and the occurrence of the abnormal lipoprotein‐X. Furthermore these results indicate that combined determinations of LCAT and LP‐X may prove to be useful techniques for differentiating intra‐ and extra‐hepatic cholestasis.
The Lipolytic Activity of Human Milk
Authors: Jubelin J. , Boyer J.
Published: March 2008

Abstract The lipolytic activity of human skimmed milk is studied with respect to pH, temperature, substrate nature and concentration and in the presence of various chemicals added to the assay medium. The enzymatic hydrolysis is maximum at pH 8 and 37° C in an emulsion of tributyrin 5 mM and in the presence of sodium taurocholate. Tributyrin is also hydrolyzed but about 15 times more slowly in the absence of this bile salt. Lipolysis of triolein does not proceed unless sodium taurocholate is added to the medium at a concentrations greater than 0.5 mM. In 10 mM sodium taurocholate, the reaction rates are approximately 7.5 and 0.5 units per mg of proteins for tributyrin and triolein, respectively. The hydrolysis of tributyrin and triacetin at concentrations below saturation is enhanced by the presence of low concentrations of NaCl, suggesting that the catalytic process depends on the presence of a substrate in the micellar form, i.e. on the action of an interfacial enzyme.
Stimulation of Pancreatic Secretion of Enzymes Acute Hypercalcaemia in Man*,**
Authors: Goebell H. , Steffen Ch. , Baltzer G. , Bode Ch.
Published: March 2008

Abstract. Acute hypercalcaemia was induced by infusion of 0.5 mEq calcium (as calcium gluconate) per kg body weight per hour. Its effect on fluid production and on concentration and output of bicarbonate, lipase, chymotrypsin, trypsin and calcium in the duodenal juice was studied in two groups of normal subjects. In group I (n = 7) the pancreas was stimulated with 0.25 clinical units of pure natural secretin per kg body weight per hour, and in group II (n=13) with one clinical unit/kg/h. The calcium infusion was superimposed after 60 minutes, and the experiment concluded 45 minutes later with a single injection of one clinical unit of pancreozymin per kg body weight. Hypercalcaemia had no effect on the secretion of fluid or bicarbonate in group I. In group II, studied with a high dose of secretin, hypercalcaemia led to an increased production of fluid but not of bicarbonate. Hypercalcaemia stimulated significantly the output of enzymes by a factor of 2–3, independently of the secretin‐stimulated flow‐rate of the juice. Output of calcium was also significantly higher in the hypercalcaemia state than in the secretin period. The stimulatory action of calcium on the pancreatic secretion of enzymes is interpreted by analogy to the known effects of hypercalcaemia on gastric secretion in man.
Influence of Extracorporeal Dialysis on Glucose Utilization and Insulin Secretion in Patients with Acute Renal Failure*
Authors: Kokot F. , Kuska J.
Published: March 2008

Abstract. The influence of haemodialysis on glucose assimilation, insulin secretion and plasma NEFA was followed in 14 patients with acute renal failure. The results obtained were compared with those from healthy subjects. As has been found in chronic renal insufficiency glucose intolerance was found in patients suffering from acute renal failure. This metabolic aberration was found despite higher mean plasma insulin levels. Treatment by haemodialysis was followed by improvement of glucose assimilation in 10 out of 14 patients. No correlation was found between the improvement of glucose assimilation after haemodialysis and insulin secretion stimulated by intravenous glucose injection. From the results it is concluded that the pathomechanism of glucose intolerance found in patients with acute renal failure does not appear to be uniform and is not necessarily related to insulin secretion.
Iron Excess, Early Glucose Intolerance and Impaired Insulin Secretion in Idiopathic Haemochromatosis
Authors: de Haan B. Bierens , Scherrer J.‐R. , Stauffacher W. , Pometta D.
Published: March 2008

Abstract. The relationship between iron storage and glucose metabolism was studied in 21 relatives of 4 patients with idiopathic haemochromatosis and in 10 healthy control subjects. In all individuals, plasma iron and iron binding capacity were measured and liver function was assessed. In addition, intravenous and oral glucose tolerance tests (IVGTT, OGTT), as well as tolbutamide (TTT) and insulin tolerance tests (ITT), were performed. Serum insulin (IRI) was measured. Liver biopsies were performed on the 21 relatives only.

In the relatives of patients with haemochromatosis, glucose tolerance was impaired and insulin secretion in response to hyperglycaemia diminished and/or delayed. Glucose intolerance increased with age but did not depend on abnormal liver function or excessive iron storage. Insulin release in response to tolbutamide was normal and insulin tolerance test failed to reveal insulin resistance.

The results suggest that:

1. There is an early glucose intolerance in healthy relatives of patients suffering from idiopathic haemochromatosis.

2. The glucose intolerance seems unrelated to measurable anomalies in iron metabolism.

3. The delayed insulin secretion in response to glucose resembles that observed in common maturity‐onset diabetes mellitus.

4. The results obtained are compatible with the hypothesis that haemochromatosis and diabetes mellitus might be two distinct but genetically linked entities.
The Relationship between Total Body Potassium and Exchangeable Body Potassium Measured at 24 Hours and 44 Hours after Administration of 43K
Authors: Boddy Keith , King Priscilla C. , Davies David L.
Published: March 2008

Abstract. Total body potassium was measured in patients by whole‐body monitoring and compared with exchangeable body potassium measured 24 h and 44 h after administration of 43K. It was confirmed that equilibration was incomplete after only 24 h but, when the 44 h exchangeable potassium was expressed as a percentage of the total body potassium or as mEq per kilogram body weight, the mean values for males and females were not significantly different from the corresponding values found here and by other workers at 24 h post‐administration. However, in a hypokalemic patient treated with carbenoxolone sodium, the exchangeable potassium did not accurately reflect the total body potassium before and after treatment or when the patient was normo‐kalaemic. The measured values of total body potassium were also compared with normal values estimated from the patient's weight, height and age, and from height and age only. The importance was demonstrated of using a relationship which does not involve the patient's weight when aberrations in body weight may exist, in this case obesity. The longer half‐life and lower radiation per μCi of 43K was advantageous but the isotope is not readily available and is more expensive than 42K because of its method of production.
The Continuous Withdrawal Method for the Quantitative Analysis of the Lower Oesophageal Sphincter (LES) in Humans
Authors: Waldeck F. , Jennewein H.‐M. , Siewert R.
Published: March 2008

Abstract. 1. The continuous withdrawal method which has been used successfully in animal experiments for recording pressure profiles in the lower oesophageal sphincter, LES, was applied for the first time in human studies. A catheter with 4 side holes which served as a pressure transmitter, was continuously withdrawn from the stomach at a constant speed (6 mm/sec.) while constantly perfused (5 ml/min.). This procedure shows numerous advantages, particularly for quantitative analysis, when compared to both the stepwise pull‐through method and an open‐side catheter lying stationary in the sphincter. Thus the profiles obtained using the continuous withdrawal method are remarkable for their definition. Displacements, which can occur with a stationary catheter, are eliminated, and the pressure maximum can be definitely determined even if there is a shift in the area of maximum pressure. – 2. Pressure profiles of the LES taken with the withdrawal method in 20 conscious subjects usually showed a gradual, and then more rapid increase from aboral to oral, which after reaching a maximum value decreased steeply and changed into sub‐zero pressures. The maximum pressure taken from the pressure profiles of 20 subjects, being the mean value of all experiments, was 19 ± 7.3 mm Hg with a mean sphincter length of 3.4 ±0.6 cm (x̄±SD). The pressure profiles could be recorded at short intervals (0.5‐2 min.) without appreciable irritation of the sphincter. – 3. The continuous withdrawal method proved especially efficient, even after an increase of the sphincter tone induced by Pentagastrin (0.6 μg/kg I. V.). The mean results of the experiments in 6 test subjects showed that the maximum pressure in the LES increased from 13 ± 6.3 mm Hg to 44.2 ± 11 mm Hg 1 min. after the injection and the mean sphincter length increased from 3.9 ±1.2 cm to 5.3±1.4cm. These effects had subsided after 7–10 min. Pressure profiles obtained in this way, as well as supplementary measurements, indicated that Pentagastrin can cause a shift of the maximum pressure area in the oral direction.
In Vitro Studies of the Rate of Proinsulin and Insulin Turnover in Seven Human Insulinomas
Authors: Creutzfeldt C. , Track N. S. , Creutzfeldt W.
Published: March 2008

Summary. Human insulinoma tissue excised from seven patients was incubated with glucose (3.0 mg/ml) and 3H‐leucine (100 μCi/ml) for a 15 min. pulse period. One third of the tissue was homogenized immediately in 0.3 M sucrose (pH 6.0), one third was homogenized after a 20 min. chase (with L‐leueine 37S μg/ml) and the remaining third after an 80 min. chase. Subcellular fractions (cell debris, mitochondria, secretory granules, microsomes and S‐100) were prepared by centrifugation. Their identity was confirmed by ultrastructural examination. Since only tumours revealing typical β‐granules were investigated the secretory granule fractions contained the same types of granules as found in the normal human B‐cell.—The S‐100 contained approximately 40% of the immuno‐reactive insulin (IRI). The secretory granule samples from five tumours were fractionated by sucrose gradient ultracentrifugation. At the three time intervals examined, a peak of radioactivity and IRI was located at 1.60 M sucrose in three of the tumours. The different granule types were not separable in the sucrose gradients. Endogenous proinsulin‐like components (proinsulin) and insulin were released throughout the incubation. During incubation of tumour tissue the ratio of IRI release to content was significantly higher than that from isolated human pancreatic islets. Newly synthesized proinsulin was detected in the medium after the 15 min. pulse in five of the tumours; radioactive proinsulin and insulin were present in all the media after the 20 and 80 min. chase periods. Islets isolated from the pancreatic tissue of two insulinoma patients showed a much slower proinsulin and insulin turnover.—These data support the conjecture that human insulinomas have a more rapid turnover of proinsulin and insulin than normal pancreatic islet tissue, apparently as the consequence of defective IRI storage and release mechanisms.
Inhibition of Phosphorylase‐a by Fructose‐1‐Phosphate, α‐Glycerophosphate and Fructose‐1,6‐Diphosphate: Explanation for Fructose‐Induced Hypoglycaemia in Hereditary Fructose Intolerance and Fructose‐1,6‐Diphosphatase Deficiency*
Authors: Kaufmann U. , Froesch E. R.
Published: March 2008

Abstract. The effect of fructose‐1‐phosphate, α‐glycerophosphate and fruetose‐1,6‐diphosphate on the activity of liver phosphorylase‐a has been investigated at different concentrations of inorganic phosphorus.—Inhibition of phosphorylase‐a by fructose‐1‐phosphate is competitive, by α‐glycerophosphate it is noncompetitive and by fructose‐1,6‐diphosphate uncompetitive. The Ki is 4 × 10‐3 M for fructose‐1‐phosphate and in the range of 5 to 6 × 10‐2 M for fructose‐1,6‐diphosphate and α‐glycerophosphate. The activity of phosphorylase‐a and its inhibition by fructose‐1‐phosphate depends very much on the concentration of inorganic phosphorus.—In fructose‐1,6‐diphosphatase deficiency glucose production from gluconeogenic precursors is impossible, whereas in hereditary fructose intolerance accumulated fructose‐1‐phosphate blocks the residual abnormal hepatic aldolase. Our findings explain fructose induced hypoglycaemia in hereditary fructose intolerance and fructose‐1,6‐diphosphatase deficiency by a block in glycogenolysis at the level of phosphorylase‐a.
Plasma 25‐Hydroxycholecalciferol in Chronic Renal Failure
Authors: Bayard F. , Bee Ph. , That H. Ton , Louvet J. P.
Published: March 2008

Abstract. 47 patients with chronic renal failure were investigated for plasma 25‐hydroxycholecalciferol (25‐OH D3) concentration, serum calcium, phosphorus, alkaline phosphatase. 22 patients had chronic haemodialysis twice weekly. There is a highly significant positive coefficient of correlation between calcaemia and 25‐OH D3 plasma concentration. Levels of serum calcium had previously been shown to correlate well with the presence and type of osteodystrophies in chronic renal failure. Since these patients may be unable to synthesize 1,25 dihydroxy D3, the metabolite of vitamin D3 considered to be active on intestine and bone, a direct role of 25‐OH D3 in the regulation of calcium metabolism may have to be considered.
Metabolism of Mono‐and Dihydroxylated Bile Acids in Preparations of Human Liver
Authors: Björkhem Ingemar , Einarsson Kurt , Hellers Göran
Published: March 2008

Abstract. The metabolism of tritium‐labelled taurodeoxycholic acid, taurochenodeoxycholic acid, taurolithocholic acid and of [24‐14C] lithocholic acid and [24‐14C] 3‐keto‐5β‐cholanoic acid was studied in fractions of human liver homogenates.—In the presence of microsomal fraction fortified with an NADPH‐generating system a small conversion of taurodeoxycholic acid into taurocholic acid occurred. No significant hydroxylation of taurochenodeoxycholic acid, taurolithocholic acid or free lithocholic acid could be detected. In the presence of microsomal fraction fortified with NAD lithocholic acid was converted into 3‐keto‐5β‐cholanoic acid. In the presence of microsomal fraction fortified with NADH, 3‐keto‐5β‐cholanoic acid was reduced to isolithocholic acid and lithocholic acid (ratio 3:1). In the presence of 100000 ×g supernatant fraction only lithocholic acid was formed from 3‐keto‐5β‐cholanoic acid.—The physiological significance of the ability of human liver to convert lithocholic acid into isolithocholic acid is discussed.
Thyrotropin Response to Thyrotropin Releasing Hormone in Normal Subjects
Authors: Weeke Jergen
Published: March 2008

Abstract. 200 (ig of synthetic thyrotropin releasing hormone (TRH) was administered intravenously to six normal men and six normal women on two occasions. A positive correlation between the basal TSH level and maximal serum TSH after TRH was found. The TSH responses in the mid‐follicular and mid‐luteal phase were similar. There was no difference in the response between the men and the women investigated. The variability was considerable, the intra‐individual coefficient of variation of the TSH response being 30 per cent when expressed as per cent increase above the basal level.
Uraemic and Normal Plasma Protein Binding of Various Cardiac Glycosides under “in vivo” Conditions*
Authors: Kramer P. , Kothe E. , Saul J. , Scheler F.
Published: March 2008

Abstract. Plasma from normal subjects and uraemic patients was obtained five minutes after injection of tritiated g‐strophantin, methyldigoxin, digoxin or digitoxin and it was dialyBed (dualclosed loop dialysis; pressure balanced to prevent fluid shift; cuprophane membrane; pH 7.4; 37 °C) against the subject's own plasma‐water obtained by means of haemodiafiltration before injection of the cardiac glycosides.–Plasma protein binding was calculated from the constant concentration difference between plasma and plasma‐water during the diffusion equilibrium after 220 min. of dialysis. This value was significantly reduced in the uraemic patients as compared to the normal subjects, although the plasma protein concentration of the two groups was not different. Methyldigoxin protein binding was reduced from 29.8 to 19.0%, digoxin from 29.4 to 21.3% and digitoxin from 93.7 to 88.3%. Protein binding of g‐strophantin could not be found neither in normal nor in uraemic plasma.–Similar differences between the different cardiac glycosides and the uraemic and normal plasma were found in the mass transfer during the first two hours of dialysis. The conclusion from these results is that in uraemic patients a more rapid onset of action and an enhanced activity of protein‐bound glycosides might be considered.–When interpreting the plasma concentration of cardiac glycosides in uraemic patients it should be remembered that the pharmacological effect depends on the unbound part of the drug, which is increased in uraemia. Although the protein binding of digitoxin is reduced by only 5.4%, the result is a doubling of the unbound glycoside concentration.
Relationship between Plasma Concentrations of Angiotensin I, Angiotensin II and Plasma Renin Activity during Cardio‐Pulmonary Bypass in Man*
Authors: Favre L. , Vallotton M. B. , Muller A. F.
Published: March 2008

Abstract. Several reports have demonstrated that the lungs are the most important site of conversion of angiotensin I to angiotensin II. The purpose of the present study was to assess the extent of extra‐pulmonary conversion hi man, during cardiopulmonary bypass. Plasma concentrations of angiotensin I and immunoreactive angiotensin II, and plasma renin activity were simultaneously determined, using specific radioimmunoassays, during extra‐corporeal circulation in 13 patients undergoing major cardiac surgery. Generally the renin‐angiotensin system was stimulated during cardiopulmonary bypass with maximum values occurring at different time. A highly significant correlation was found between plasma renin activity and angiotensin I and II concentrations respectively, as well as between these two peptides. Positive correlations were also obtained between arterial and venous samples for plasma renin activity and angiotensin I and II. Thus the presence of angiotensin II in plasma in the absence of pulmonary circulation and its parallel variations with plasma renin activity indicate that converting activity by extra‐pulmonary sources is not negligible.
Influence of Body Position on the Anginal Threshold during Leg Exercise
Authors: Bygdeman Stellan , Wahren John
Published: March 2008

Abstract. The circulatory adaptation to leg exercise in the supine and sitting positions with stepwise increased work loads was studied in twelve patients with signs of coronary heart disease. In four patients right heart catheterization was performed. Anginal pain appeared during exercise in both body positions in all patients, but at a lower work load and lower pulmonary oxygen uptake during supine exercise. Heart rate and systolic blood pressure were lower and the systolic ejection period was longer at the occurrence of angina during supine exercise. The calculated pressure‐time per minute was significantly lower during exercise in the supine position. Catheterization data suggested a greater rise in left ventricular filling pressure with supine exercise. It is concluded that the differences in work tolerance for the two positions are partly due to a lower mechanical efficiency and may partly be secondary to the augmented venous return and increased left ventricular filling pressure observed during supine exercise. The augmented filling pressure will tend both to increase heart volume–and thereby augment myocardial oxygen requirements–and to compromise coronary perfusion and thus reduce myocardial oxygen supply during supine exercise.