bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attenuated pulse size, disorderly growth hormone and prolactin secretion with preserved nyctohemeral rhythm distinguish irradiated from surgically treated acromegaly patients
Authors: Van Der Klaauw A. A. , Pereira A. M. , Van Thiel S. W. , Frolich M. , Iranmanesh A. , Veldhuis J. D. , Roelfsema F. , Romijn J. A. 
Published: January 2007

SummaryBackground  Radiation induces time‐dependent loss of anterior pituitary function, attributed to damage of the pituitary gland and hypothalamic centres. The development of growth hormone deficiency (GHD) in irradiated acromegaly patients is not well defined.Objective  Detailed analysis of spontaneous 24‐h GH and prolactin (PRL) secretion in relation to other pituitary functions and serum IGF‐I concentrations in an attempt to find criteria for GHD in acromegalic patients with a GH response < 3 µg/l during the insulin tolerance test (ITT).Design  Plasma hormone profiles obtained by 10 min sampling for 24 h in postoperatively irradiated acromegalic patients, compared with patients cured by surgery only and matched healthy controls.Setting/participants  University setting. Fifteen subjects in each group.Outcome measures  GH and PRL secretory parameters quantified by deconvolution, cluster, cosinor and approximate entropy (ApEn) analyses, IGF‐I concentrations.Results  Irradiation attenuated pulsatile secretion of GH and PRL, but total PRL secretion was unchanged. GH and PRL secretory regularity were diminished. Circadian timing remained intact. Pulsatile GH secretion and IGF‐I were correlated (R = 0·30, P = 0·04). Criteria of pulsatile GH secretion = 12 µg/l/24 h and ApEn = 0·800 separated 12 of 15 irradiated patients from all others.Conclusion  Irradiated acromegaly patients with a subnormal GH response to ITT have very limited spontaneous GH secretion, with specific attenuation of the size of GH bursts and a highly irregular pattern, but with retained diurnal properties. These patients are thus likely GH‐deficient and might benefit from GH replacement.
Differential regulation of visfatin and adiponectin in pregnancies with normal and abnormal placental function
Authors: Fasshauer M. , Blüher M. , Stumvoll M. , Tönessen P. , Faber R. , Stepan H. 
Published: January 2007

SummaryObjective   There is compelling evidence that insulin resistance may play a pivotal role in the development of pregnancy complications including pre‐eclampsia and intrauterine growth restriction (IUGR). As dysregulation of visfatin and adiponectin is found in insulin resistance, both adipokines might contribute to pregnancy disorders.Patients and methods   Plasma levels of visfatin and adiponectin were quantified in second‐trimester pregnancies with abnormal uterine perfusion and in third‐trimester pregnancies with IUGR as compared to healthy controls.Results   Mean plasma adiponectin levels were significantly increased in women with pathological perfusion (7078 ± 789 ng/ml) as compared to normal uterine perfusion (4481 ± 1183 ng/ml) (P < 0·05) whereas visfatin plasma concentrations were not different between these groups. Visfatin levels were significantly elevated in women with IUGR (140·1 ± 10 ng/ml) as compared to patients with normal outcome (65·5 ± 11 ng/ml) (P < 0·05). By contrast, adiponectin plasma concentrations were not significantly altered in women with IUGR.Conclusions   Our data support the view that the adipokines visfatin and adiponectin are differentially regulated in pregnancy complications.
Thyroid disease and female reproduction
Authors: Poppe Kris , Velkeniers Brigitte , Glinoer Daniel 
Published: January 2007

SummaryThe menstrual pattern is influenced by thyroid hormones directly through impact on the ovaries and indirectly through impact on SHBG, PRL and GnRH secretion and coagulation factors. Treating thyroid dysfunction can reverse menstrual abnormalities and thus improve fertility. In infertile women, the prevalence of autoimmune thyroid disease (AITD) is significantly higher compared to parous age‐matched women. This is especially the case in women with endometriosis and polycystic ovarian syndrome (PCOS). AITD does not interfere with normal foetal implantation and comparable pregnancy rates have been observed after assisted reproductive technology (ART) in women with and without AITD. During the first trimester, however, pregnant women with AITD carry a significantly increased risk for miscarriage compared to women without AITD, even when euthyroidism was present before pregnancy. It has also been demonstrated that controlled ovarian hyperstimulation (COH) in preparation for ART has a significant impact on thyroid function, particularly in women with AITD. It is therefore advisable to measure thyroid function and detect AITD in infertile women before ART, and to follow‐up these parameters after COH and during pregnancy when AITD was initially present. Women with thyroid dysfunction at early gestation stages should be treated with l‐thyroxine to avoid pregnancy complications. Whether thyroid hormones should be given prior to or during pregnancy in euthyroid women with AITD remains controversial. To date, there is a lack of well‐designed randomized clinical trials to elucidate this controversy.
Metabolic effects of growth hormone (GH) replacement in children and adolescents with severe isolated GH deficiency due to a GHRH receptor mutation
Authors: Gleeson Helena , Barreto Elenilde S. de A. , Salvatori Roberto , Costa Liana , Oliveira Carla R. P. , Pereira Rossana M. C. , Clayton Peter , Aguiar‐Oliveira Manuel H. 
Published: January 2007

SummaryBackground  The interpretation of the true effect of GH replacement therapy (GHRT) on metabolic status in GH deficiency (GHD) is often complicated by differing aetiologies of GHD and by the presence of additional hormone deficits.Objective  To study the growth and response of the lipid profile and body composition to GHRT in a cohort of children with the same mutation in the GHRH receptor gene.Design  Nine GH‐deficient subjects (mean age 12·8 years, range 5–17·5 years; three male) in a rural community in Northeast Brazil were treated with GHRT for 2 years and compared with indigenous normal controls.Main Outcome Measures  Total cholesterol (TC), low density lipoprotein cholesterol (LDL‐C), high density lipoprotein cholesterol (HDL‐C), triglycerides (TG) and body composition were measured at baseline and after 3, 12 and 24 months of GHRT.Results  At baseline, the subjects with GHD had an adverse lipid profile, including elevated TC, elevated LDL‐C and elevated TG. GHRT normalized TG in 3 months, LDL‐C in 12 months and TC in 24 months. At baseline, older pubertal subjects with GHD had adverse body composition, including higher percentage fat mass (%FM), and GHRT induced a reduction in %FM that was maintained after 24 months. By contrast, younger prepubertal subjects did not have an adverse body composition.Conclusions  Lipid profile was abnormal at baseline, while abnormal body composition was only seen in older subjects in late puberty, indicating that body composition is less sensitive to the effect of GHD than lipid profile. GHRT improves lipid profile at all ages, while it affects body composition only towards the end of growth, emphasizing its importance in achieving normal somatic development in the transition period.
Clinical insights into adipsic diabetes insipidus: a large case series
Authors: Crowley R. K. , Sherlock M. , Agha A. , Smith D. , Thompson C. J. 
Published: January 2007

SummaryObjective  Adipsic diabetes insipidus (DI) causes significant hypernatraemia. Morbidity and mortality data for patients with adipsic DI have been previously published as single case reports, rather than as formal trials or case series from units with established management protocols. Our objective was to describe morbidity and mortality in patients with adipsic DI attending a tertiary referral centre, representing the largest reported series of adipsic DI, and to suggest management protocols for such patients, based on our extensive experience of this condition.Design  Arginine vasopressin (AVP) responses to hypotension were recorded during trimetaphan infusion. Sleep abnormalities were identified using overnight oximetry or polysomnography. Case‐note analysis defined other clinical abnormalities including seizures and thrombotic episodes. Important clinical points for the management of these patients are highlighted.Patients  Thirteen patients with adipsic DI defined by thirst and plasma AVP responses to hypertonic saline infusion.Results  All patients had absent AVP and thirst responses to osmotic stimulation, with subnormal water intake. Five patients had absent AVP responses to hypotension; the remainder had normal responses. Eight patients were obese [body mass index (BMI) > 30 kg/m2], and three were overweight (BMI > 25 kg/m2). Seven patients had sleep apnoea, of whom three died at 36 years or younger. Four patients developed venous thrombosis during episodes of hypernatraemia. Two patients had thermoregulatory dysfunction and seven patients had seizure activity.Conclusion  Adipsic DI is associated with significant morbidity and mortality. Physicians should be aware of associated, treatable hypothalamic abnormalities such as obesity, sleep apnoea, seizures and thermoregulatory disorders when managing adipsic DI.
Intra‐adipose sex steroid metabolism and body fat distribution in idiopathic human obesity
Authors: Wake Deborah J. , Strand Magnus , Rask Eva , Westerbacka Jukka , Livingstone Dawn E. W. , Soderberg Stefan , Andrew Ruth , Yki‐Jarvinen Hannele , Olsson Tommy , Walker Brian R. 
Published: January 2007

SummaryObjective  Causes of visceral fat accumulation include glucocorticoid excess or decreased oestrogen/androgen ratio either in plasma or within adipose tissue. In obese subjects, the intra‐adipose cortisol‐generating enzyme 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD1) is increased, but information on sex steroid signalling is sparse. We aimed to test associations between body fat or fat distribution and mRNA transcript levels for androgen and oestrogen receptors and for enzymes metabolizing sex steroids in adipose tissue.Design  A cross‐sectional study.Patients  Forty‐five healthy men and women with body mass index (BMI) 21–36 kg/m2.Measurements  In subcutaneous adipose biopsies we measured mRNAs for enzymes metabolizing local oestrogens (aromatase) and androgens [5α‐reductase type 1; AKR1C2 (3α‐HSD3); AKR1C3 (17β‐HSD5, 3α‐HSD2)] and for sex steroid receptors [oestrogen receptor (ER)‐α and androgen receptor (AR)]. We related these to body fat mass and distribution.Results  Generalized obesity (BMI) was associated with increased aromatase mRNA (r = 0·35, P < 0·05). Central obesity (waist : hip ratio) was associated with mRNA for AKR1C2 (r = 0·28, P < 0·05) and AKR1C3 (r = 0·38, P < 0·01) but not aromatase (r = 0·06). 5α‐Reductase type 1, ER and AR mRNA levels did not predict fat amount or its distribution.Conclusion  These data on transcript levels suggest that, in idiopathic obesity, increased intra‐adipose oestrogen generation by aromatase predicts peripheral fat distribution, while androgen metabolism by AKR1C isoforms predicts central fat distribution, supporting the hypothesis that intra‐adipose sex steroid metabolism is a determinant of gynoid vs. android patterns of body fat.
Assessment of left ventricular diastolic function and the Tei index by tissue Doppler imaging in patients with primary hyperparathyroidism
Authors: Baykan Merih , Erem Cihangir , Erdogan Turan , Ersöz Halil Önder , Gedikli Ömer , Korkmaz Levent , Kücükosmanoglu Mehmet , Haclhasanoglu Arif , Kaplan Sahin , Çelik Sükrü 
Published: January 2007

SummaryBackground  The aim of this study was to assess left ventricular (LV) systolic and diastolic function and myocardial performance (the Tei index) by tissue Doppler imaging (TDI) in patients with primary hyperparathyroidism (PHPT).Methods  We prospectively evaluated 21 patients with PHPT [nine women, 12 men; aged 50 ± 11 years, serum calcium 2·9 ± 0·17 mmol/l, intact PTH (iPTH) 51·5 ± 52·1 pmol/l] and 27 healthy control subjects (13 women, 14 men; aged 49 ± 10 years, serum calcium 2·35 ± 0·12 mol/l, iPTH 2·9 ± 0·9 pmol/l). LV systolic and diastolic function was assessed by conventional echocardiography and by TDI. Early diastolic (Em), late diastolic (Am) and peak systolic (Sm) mitral annular velocities, the ratio Em/Am and the Tei index were calculated from TDI measurements. Mitral inflow velocities, colour M‐mode flow propagation velocity (Vp), relative wall thickness (RWT) and LV mass index (LVMI) were assessed by two‐dimensional echocardiography.Results  Em and Em/Am were lower in patients with PHPT than in healthy controls (11·2 ± 1·5 cm/s vs. 13·5 ± 2·5 cm/s, P = 0·005; 0·94 ± 0·27 vs. 1·36 ± 0·44, P = 0·02, respectively). In patients with PHPT, the Tei index was significantly higher than that in controls (0·45 ± 13·6 vs. 0·33 ± 8·1, P = 0·02). Peak (E) velocity and the ratio of E to peak late (A) velocity (E/A) were lower in those with PHPT than in those without (59 ± 15 cm/s vs. 72 ± 19 cm/s, P = 0·02; 0·8 ± 0·15 vs. 1·1 ± 0·33, P = 0·001, respectively). Patients with PHPT had significantly higher RWT (0·50 ± 0·02 cm vs. 0·41 ± 0·02 cm, P = 0·0001), isovolumetric relaxation time (IVRT) (115 ± 13 ms vs. 103 ± 11 ms P = 0·04) and A velocity (79 ± 16 cm/s vs. 68 ± 13 cm/s P = 0·05) than controls. Vp was lower in PHPT patients than in healthy subjects (42 ± 9·98 cm/s vs. 54 ± 19·01 cm/s P = 0·04). There were no significant differences between the two groups regarding LV end‐diastolic and end‐systolic dimensions, LVMI, deceleration time of the mitral E wave, Am and Sm.Conclusion  TDI analysis of mitral annular velocities, Em/Am and the Tei index is useful for assessing LV diastolic dysfunction in patients with PHPT. The parameters obtained from the lateral mitral annulus by TDI can be used for the identification of LV diastolic dysfunction in PHPT patients.
The aryl hydrocarbon receptor‐interacting protein gene is rarely mutated in sporadic GH‐secreting adenomas
Authors: Iwata Takeo , Yamada Shozo , Mizusawa Noriko , Golam Hossain MD. , Sano Toshiaki , Yoshimoto Katsuhiko 
Published: January 2007

SummaryBackground  Recently, germline mutations of aryl hydrocarbon receptor‐interacting protein (AIP) gene located on 11q13 were identified in patients with pituitary adenoma predisposition.Aim/patients and methods  We investigated the involvement of the AIP gene in one family with isolated familial somatotropinomas (IFS). To investigate the role of AIP in sporadic GH‐secreting adenomas, we first analysed somatic mutations in 40 tumours. Second, DNA from corresponding leucocytes was analysed in tumours showing genetic changes of the AIP gene.Results  Germline mutation of AIP was found in an IFS family. Bi‐allelic inactivation of AIP by a combination of germline mutation and loss of heterozygosity were confirmed in two pituitary adenomas. Mutation analysis of the AIP gene in the 40 sporadic GH‐secreting adenomas showed no mutations except for a missense mutation, suggesting that germline mutations in patients diagnosed with sporadic acromegaly or gigantism were rare. In a patient with gigantism, a missense mutation of V49M was identified at the germline level.Conclusion  Based on these results, we conclude that the loss of function of AIP contributes to IFS, but not for most Japanese sporadic GH‐secreting adenomas.
Management options for river conservation planning: condition and conservation re‐visited
Authors: LINKE SIMON , PRESSEY ROBERT L. , BAILEY ROBERT C. , NORRIS RICHARD H. 
Published: January 2007

Summary1. Systematic conservation planning is a process widely used in terrestrial and marine environments. A principal goal is to establish a network of protected areas representing the full variety of species or ecosystems. We suggest considering three key attributes of a catchment when planning for aquatic conservation: irreplaceability, condition and vulnerability.2. Based on observed and modelled distributions of 367 invertebrates in the Australian state of Victoria, conservation value was measured by calculating an irreplaceability coefficient for 1854 subcatchments. Irreplaceability indicates the likelihood of any subcatchment being needed to achieve conservation targets. We estimated it with a bootstrapped heuristic reserve design algorithm, which included upstream–downstream connectivity rules. The selection metric within the algorithm was total summed rarity, corrected for protected area.3. Condition was estimated using a stressor gradient approach in which two classes of geographical information system Layers were summarised using principal components analysis. The first class was disturbance measures such as nutrient and sediment budgets, salinisation and weed cover. The second class was land use layers, including classes of forestry, agricultural and urban use. The main gradient, explaining 56% of the variation, could be characterised as agricultural disturbance. Seventy‐five per cent of the study area was classified as disturbed.4. Our definition of vulnerability was the likelihood of a catchment being exposed to a land use that degrades its condition. This was estimated by comparing land capability and current land use. If land was capable of supporting a land use that would have a more degrading effect on a river than its current tenure, it was classified vulnerable (66% of the study area). 79% of catchments contained more then 50% vulnerable land.5. When integrating the three measures, two major groups of catchments requiring urgent conservation measures were identified. Seven per cent of catchments were highly irreplaceable, highly vulnerable but in degraded condition. These catchments were flagged for restoration. While most highly irreplaceable catchments in good condition were already protected, 2.5% of catchments in this category are on vulnerable land. These are priority areas for assigning river reserves.
Alternative states in the phytoplankton of Lake Kinneret, Israel (Sea of Galilee)
Authors: ROELKE DANIEL L. , ZOHARY TAMAR , HAMBRIGHT K. DAVID , MONTOYA JOSÉ V. 
Published: January 2007

Summary1. Through analyses of a 34‐year record of phytoplankton, zooplankton and physicochemical parameters from Lake Kinneret, Israel, we show that distinct and persistent phytoplankton assemblage states occurred from winter to summer.2. The most obvious characteristic of these states was the presence or absence of a spring bloom of the dinoflagellate, Peridinium gatunense.3. Analyses of the data within the framework of the alternative states model revealed a possible complex triggering mechanism, and system hysteresis.4. A change in zooplankton biomass and body size coincident with changes in predation pressure associated with the collapse of the Kinneret Bleak, Acanthobrama terraesanctae, fishery appeared to be the ‘slow changing’ variable in the context of the alternative states model. Alternative phytoplankton states were only possible after this variable crossed a threshold in 1993–94, following the collapse of the fishery.5. When alternative states were possible, some physicochemical parameters and the structure of the zooplankton assemblage appeared to control which phytoplankton state emerged in a given year. In years without a P. gatunense bloom, important physicochemical parameters in winter included low NO3 loading, high water temperature, high water level, a deeper thermocline, low transparency, high concentrations of NO3 and Cl in the epilimnion, and low concentration of epilimnetic total phosphorus. In addition, the cladoceran Chydorus sphaericus and adults of the copepod Mesocyclops ogunnus were observed in winter in years without a bloom.6. Zooplankton biomass and body size of some taxa have recovered since the 1993–94 collapse of the fishery, yet incidence of both phytoplankton states in Lake Kinneret was still possible. Within the framework of the alternative states model, this suggests that the slow changing variable threshold where alternative states became possible is different from the threshold where alternative states will no longer be possible. In other words, the system is characterised by a hysteresis.
Riverine invertebrate assemblages are degraded more by catchment urbanisation than by riparian deforestation
Authors: WALSH CHRISTOPHER J. , WALLER KYLIE A. , GEHLING JANELLE , NALLY RALPH MAC 
Published: January 2007

Summary1. Restoration of riparian forests has been promoted as a means of mitigating urban impacts on stream ecosystems. However, conventional urban stormwater drainage may diminish the beneficial effect of riparian forests.2. The relative effects of riparian deforestation and catchment urbanisation on stream ecosystems have rarely been discriminated because urban land use and riparian degradation usually covary. However, land use at three scales (channel canopy cover along a 100‐m site, riparian forest cover within 200 m of the channel for 1 km upstream, and catchment imperviousness) covaried only weakly along the lowland Yarra River, Victoria, Australia.3. We tested the extent to which each land use measure explained macroinvertebrate assemblage composition on woody debris and in the sediments of pools or runs in the mainstem Yarra River in autumn and spring 1998.4. Assemblage composition in both habitats and in both seasons was most strongly correlated with proportion of catchment covered by impervious surfaces. Sites with higher imperviousness had fewer sensitive taxa (those having a strong positive influence on indicators of biological integrity) and more taxa typical of degraded urban streams. Sensitive taxa rarely occurred in sites with >4% total imperviousness. However, within sites of similar imperviousness, those with more riparian forest cover had more dipteran taxa. Channel canopy cover did not explain assemblage composition strongly.5. Riparian forest cover may influence richness of some macroinvertebrate taxa, but catchment urbanisation probably has a stronger effect on sensitive taxa. In catchments with even a small amount of conventionally drained urban land, riparian revegetation is unlikely to have an effect on indicators of stream biological integrity. Reducing the impacts of catchment urbanisation through dispersed, low‐impact drainage schemes is likely to be more effective.