bluuebunny/crossref_metadata_2025_split huggingface dataset:
Revisiting two theorems of Curto and Fialkow on moment matrices
Authors: Laurent Monique 
Published: June 2005

We revisit two results of Curto and Fialkow on moment matrices. The first result asserts that every sequence

y
∈

R

Z

+
n

y\in \mathbb {R}^{\mathbb {Z}^n_+}

whose moment matrix

M
(
y
)

M(y)

is positive semidefinite and has finite rank

r
r

is the sequence of moments of an

r
r

-atomic nonnegative measure

μ
\mu

on

R

n

\mathbb {R}^n

. We give an alternative proof for this result, using algebraic tools (the Nullstellensatz) in place of the functional analytic tools used in the original proof of Curto and Fialkow. An easy observation is the existence of interpolation polynomials at the atoms of the measure

μ
\mu

having degree at most

t
t

if the principal submatrix

M
t

(
y
)

M_t(y)

of

M
(
y
)

M(y)

(indexed by all monomials of degree

≤
t

\le t

) has full rank

r
r

. This observation enables us to shortcut the proof of the following result. Consider a basic closed semialgebraic set

F
=
{
x
∈

R

n

∣

h
1

(
x
)
≥
0
,
…
,

h
m

(
x
)
≥
0
}

F=\{x\in \mathbb {R}^n\mid h_1(x)\ge 0, \ldots ,h_m(x)\ge 0\}

, where

h
j

∈

R

[

x
1

,
…
,

x
n

]

h_j\in \mathbb {R}[x_1,\ldots ,x_n]

and

d
:=

max

j
=
1

m

⁡
⌈
deg
⁡
(

h
j

)

/

2
⌉

d:=\operatorname {max}_{j=1}^m \lceil \operatorname {deg}(h_j)/2\rceil

. If

M
t

(
y
)

M_t(y)

is positive semidefinite and has a flat extension

M

t
+
d

(
y
)

M_{t+d}(y)

such that all localizing matrices

M

t

(

h
j

∗
y
)

M_{t}(h_j\ast y)

are positive semidefinite, then

y
y

has an atomic representing measure supported by

F
F

. We also review an application of this result to the problem of minimizing a polynomial over the set

F
F

.
Networks and epidemic models
Authors: Keeling Matt J , Eames Ken T.D 
Published: June 2005

Networks and the epidemiology of directly transmitted infectious diseases are fundamentally linked. The foundations of epidemiology and early epidemiological models were based on population wide random-mixing, but in practice each individual has a finite set of contacts to whom they can pass infection; the ensemble of all such contacts forms a ‘mixing network’. Knowledge of the structure of the network allows models to compute the epidemic dynamics at the population scale from the individual-level behaviour of infections. Therefore, characteristics of mixing networks—and how these deviate from the random-mixing norm—have become important applied concerns that may enhance the understanding and prediction of epidemic patterns and intervention measures.Here, we review the basis of epidemiological theory (based on random-mixing models) and network theory (based on work from the social sciences and graph theory). We then describe a variety of methods that allow the mixing network, or an approximation to the network, to be ascertained. It is often the case that time and resources limit our ability to accurately find all connections within a network, and hence a generic understanding of the relationship between network structure and disease dynamics is needed. Therefore, we review some of the variety of idealized network types and approximation techniques that have been utilized to elucidate this link. Finally, we look to the future to suggest how the two fields of network theory and epidemiological modelling can deliver an improved understanding of disease dynamics and better public health through effective disease control.
Population pharmacokinetics of imatinib mesylate in patients with chronic‐phase chronic myeloid leukaemia: results of a phase III study
Authors: Schmidli H. , Peng B. , Riviere G‐J. , Capdeville R. , Hensley M. , Gathmann I. , Bolton A. E. , Racine‐Poon A. 
Published: June 2005

AimsThis study was designed to investigate the biochemical and physiological covariates or comedications that affect the pharmacokinetics of imatinib mesylate in patients with chronic‐phase chronic myeloid leukaemia (CP CML).MethodsPharmacokinetic data were analyzed in 371 patients receiving 400 mg imatinib once daily during a phase III trial of imatinib vs interferon‐alfa plus cytarabine for the treatment of newly diagnosed CP CML. Covariates included age, weight, sex, ethnicity, haemoglobin (Hb) concentration, white blood cell (WBC) count, liver function, and creatinine concentration. Blood samples for imatinib analysis were taken on treatment days 1 and 29. Nonlinear mixed effects modelling was used for the population pharmacokinetic analysis.ResultsPopulation mean estimates (95% confidence interval) at day 1 for apparent clearance (CL) and apparent volume of distribution (V) of imatinib were 14 (13‐15) l h−1 and 252  (237‐267)  l,  respectively.  Modelling  suggested  that  CL  decreased  by  4  (3‐5) l h−1 from day 1 to day 29, whereas V remained unchanged. Interindividual variability in CL and V was 32% and 31%, respectively. Weight, Hb, and WBC count demonstrated small effects on CL and V. Doubling body weight or Hb or halving the WBC count was associated with a 12%, 86% and 8% increase in CL, respectively, and a 32%, 60% and 5% increase in V, respectively. Comedications showed no clear effects on imatinib CL.ConclusionsPopulation covariates and coadministered drugs minimally affected imatinib pharmacokinetics in newly diagnosed CP CML patients.
Deep vein thrombosis and pulmonary embolism reported in the Prescription Event Monitoring Study of Yasmin®
Authors: Pearce Hilary M. , Layton Deborah , Wilton Lynda V. , Shakir Saad A. W. 
Published: June 2005

AimTo evaluate cases of deep vein thrombosis (DVT) and pulmonary embolism (PE) reported in a prescription event monitoring study of Yasmin®, an oral contraceptive.MethodsReports of DVT/PE and events suggestive of DVT/PE were followed up by questionnaire.ResultsThirteen cases (DVT five; PE eight), each with possible risk factor(s), were identified in 15 645 females using Yasmin®. Applying complete case analysis, the crude incidence rate was 13.7 cases per 10 000 woman‐years (95% confidence interval 7.3, 23.4).ConclusionsYasmin is associated with venous thromboembolism. An incidence rate has been calculated, but this may be subject to bias and should be interpreted with caution.
Enantioselective disposition of lansoprazole in relation to CYP2C19 genotypes in the presence of fluvoxamine
Authors: Miura Masatomo , Tada Hitoshi , Yasui‐Furukori Norio , Uno Tsukasa , Sugawara Kazunobu , Tateishi Tomonori , Suzuki Toshio 
Published: June 2005

AimsLansoprazole is affected by polymorphism of CYP2C19. The aim of this study was to examine the effects of fluvoxamine, a CYP2C19 inhibitor, on the pharmacokinetics of each lansoprazole enantiomer among three different CYP2C19 genotype groups.MethodsEighteen healthy subjects, of whom six each were homozygous extensive metabolizers (homEMs), heterozygous extensive metabolizers (hetEMs), or poor metabolizers (PMs) for CYP2C19, participated in the study. Each subject received either placebo or fluvoxamine, 25 mg twice daily for 6 days, then a single oral dose of 60 mg of racemic lansoprazole. The plasma concentrations of lansoprazole enantiomers and lansoprazole sulphone were subsequently measured for 24 h post lansoprazole administration using liquid chromatography.ResultsIn the homEMs and hetEMs, fluvoxamine significantly increased the AUC(0, ∞) and Cmax and prolonged the elimination half‐life of both (R)‐ and (S)‐lansoprazole, whereas in the PMs, the only statistically significant effect of fluvoxamine was on the AUC(0, ∞) for (R)‐lansoprazole. The mean fluvoxamine‐mediated percent increase in the AUC(0, ∞) of (R)‐lansoprazole in the homEMs compared with the PMs was significant (P = 0.0117); however, Cmax did not differ among the three CYP2C19 genotypes. On the other hand, fluvoxamine induced a significant percent increase in both the AUC(0, ∞) and Cmax for (S)‐lansoprazole in the homEMs compared with the hetEMs (P = 0.0007 and P = 0.0125, respectively) as well as compared with the PMs (P < 0.0001 for each parameter). The mean R : S ratio for AUC(0, ∞) of lansoprazole in the homEMs was significantly different between the placebo and the fluvoxamine treatment groups (12.7 (9.1, 16.8) vs 6.4 (5.4, 7.4), respectively, P < 0.0001), though not in the PMs (5.5 (4.3, 6.7) vs 5.9 (5.3, 6.5), respectively).ConclusionsThe magnitude of the contribution of CYP2C19 to the metabolism of (S)‐lansoprazole is much greater compared with that of the (R)‐enantiomer. In extensive metabolizers, hepatic CYP2C19 plays an important role in the absorption and elimination of lansoprazole, particularly the (S)‐enantiomer.
Efficacy of ACE‐inhibitor therapy on renal disease in glycogen storage disease type 1: a multicentre retrospective study
Authors: Melis D. , Parenti G. , Gatti R. , Casa R. Della , Parini R. , Riva E. , Burlina A. B. , Vici C. Dionisi , Di Rocco M. , Furlan F. , Torcoletti M. , Papadia F. , Donati A. , Benigno V. , Andria G. 
Published: June 2005

SummaryBackground  The efficacy of ACE‐inhibitors in decreasing microalbuminuria and proteinuria has been reported in a few patients with glycogen storage disease type 1 (GSD1); however, no case‐control study has ever been published.Aim  The aim of the current study was to evaluate the efficacy of ACE‐inhibitors in reducing glomerular hyperfiltration, microalbuminuria and proteinuria, and in delaying the progression of renal damage.Patients and methods  Ninety‐five patients (median age at the time of the study: 14·5 years) were enrolled from nine Italian referral centres for metabolic diseases. A retrospective study of a 10‐year follow‐up was conducted in order to compare the evolution of these parameters in treated patients with those who were not treated with ACE‐inhibitors.Results  A significant and progressive decrease of glomerular filtration rate was observed in treated patients vs. those who were not treated with ACE‐inhibitors (P < 0·05). No difference was observed for microalbuminuria and proteinuria between the two groups of patients. Moreover, the ACE‐inhibitors significantly delayed the progression from glomerular hyperfiltration to microalbuminuria, but not that from microalbuminuria to proteinuria.Conclusions  The results of the present study underline the importance of a strict follow‐up of renal function in GSD1 patients. The detection of glomerular hyperfiltration suggests precocious initiation of ACE‐inhibitor treatment to delay the progression of renal damage. A randomized prospective study is needed to establish for certain the real effectiveness of this treatment in GSD1 patients.
Long‐term remission following withdrawal of dopamine agonist therapy in subjects with microprolactinomas
Authors: Biswas M. , Smith J. , Jadon D. , McEwan P. , Rees D. A. , Evans L. M. , Scanlon M. F. , Davies J. S. 
Published: June 2005

SummaryObjective  Reports suggest that up to 70% of patients with microprolactinomas treated with dopamine agonist therapy may achieve long‐term normoprolactinaemic remission following drug withdrawal. Yet, there is no consensus on the duration of therapy nor is therapeutic interruption universally practised. We have assessed remission rates in a large cohort of treatment‐naive subjects with microprolactinomas. Subjects received dopamine agonist (DA) therapy with either cabergoline or bromocriptine for a period of 2 to 3 years in the majority of cases, followed by a trial of treatment withdrawal.Design  Retrospective analysis of clinic records of 89 patients (mean age 32·7 ± 8·4 years, 84 women and 5 men) who had received either cabergoline (n = 67) (0·5–3 mg weekly) or bromocriptine (n = 22) (2·5–10 mg daily) for a mean duration of 3·1 years.Results  Following withdrawal of therapy, 57 subjects developed recurrence (64%) and the mean time to recurrence was 9·6 months (range 1–44 months), while 32 subjects (36%) remained in remission beyond 1 year (mean 3·6 years, range 1–7 years). There was no difference in remission rates between subjects treated with cabergoline (n = 21) and bromocriptine (n = 11), but a direct relationship between pretreatment prolactin concentration and risk of recurrent symptomatic hyperprolactinaemia was observed. No subjects developed clinical features to suggest tumour expansion following therapeutic discontinuation.Conclusions  This study confirms that abrupt withdrawal of chronic dopamine agonist therapy, following 2 to 3 years of treatment is safe and associated with long‐term remission in 30–40% of subjects with microprolactinomas. This therapeutic strategy is convenient and applicable in clinical practice.
Postoperative treatment of clinically nonfunctioning pituitary adenomas with dopamine agonists decreases tumour remnant growth
Authors: Greenman Y. , Tordjman K. , Osher E. , Veshchev I. , Shenkerman G. , Reider‐Groswasser I. I. , Segev Y. , Ouaknine G. , Stern N. 
Published: June 2005

SummaryObjective  There is no consensus as to the optimal postoperative treatment of patients with clinically nonfunctioning pituitary adenomas (NFPA) in whom total tumour removal has not been achieved. In this study we assessed whether dopamine agonist (DA) treatment can prevent postoperative remnant enlargement in NFPA.Design and methods  Thirty‐three patients (25 men/8 women; mean age, 61·7 ± 11·2 years; mean follow‐up, 40·6 ± 4·8 months) were treated with DA, and their outcome was compared to that of 47 untreated patients (33 men/14 women; mean age, 59 ± 2 years; mean follow‐up, 42·9 ± 4·2 months).Results  Tumour mass decreased or remained stable in 18/20 patients in whom DA treatment was initiated upon detection of residual tumour on postoperative MRI (group I). In 13 subjects (group II), DA therapy was started when tumour remnant growth became evident during the course of routine follow‐up. Tumour growth stabilized or decreased in 8/13 (61·5%) of these patients. In contrast, tumour size remained stable in only 38·3% (18/47) of the untreated subjects (P < 0·0001 for comparisons among the three groups) and increased in the remaining 29 patients. Tumour enlargement free mean survival time was 103·7 ± 8·8 months (CI 86·3–121) for group I, 43·9 ± 9·6 months (CI 25·2–62·8) for group II and 36·7 ± 3·8 (CI 29·2–44·2) for the control group (P = 0·0017). Treatment vs. control hazard ratio for tumour enlargement was 0·135 for group I (P = 0·007, 95% CI 0·032–0·577) and 0·892 for group II (P = 0·817; 95% CI 0·34–2·34).Conclusions  Dopamine agonist therapy is associated with a decreased prevalence of residual tumour enlargement in patients with nonfunctioning pituitary adenomas, particularly when treatment is instituted before tumour remnant growth is detected.
Characterization of antipituitary antibodies targeting pituitary hormone‐secreting cells in idiopathic growth hormone deficiency and autoimmune endocrine diseases
Authors: De Bellis Annamaria , Bizzarro Antonio , Perrino Silvia , Coronella Concetta , Conte Marisa , Pasquali Daniela , Sinisi Antonio Agostino , Betterle Corrado , Bellastella Antonio 
Published: June 2005

SummaryObjective  In order to investigate whether somatotrophs are the target of antipituitary antibodies (APA) in adult patients with growth hormone deficiency (GHD), we studied the sera of 37 APA positive patients.Patients  Patients were grouped as follows: nine patients with APA at high titre (> 1 : 8) affected by apparently idiopathic GHD; four of them (group 1a) with isolated GHD diagnosed during childhood and five with GHD diagnosed during adulthood associated with autoimmune endocrine diseases (group 1b), and 28 patients with autoimmune endocrine diseases without pituitary impairment, previously found positive for APA at low titre (1 : 8, group 2).Measurements  APA were evaluated by a four‐layer double indirect immunofluorescence technique.Results  In group 1a patients, APA immunostained exclusively GH‐producing cells. In group 1b patients, APA were directed not only to GH‐ but also to other pituitary hormone‐producing cells. In group 2 patients, APA were directed selectively to PRL‐producing cells and rarely to some GH‐producing cells.Conclusions  In the present study, we demonstrated that GH‐secreting cells are the target of the autoimmune reaction in autoimmune GHD and that the immunostaining of only the somatotrophs is typical of isolated GHD. In contrast, the finding of diffuse staining of APA indicates the need to search for other autoimmune diseases. Finally, the presence of APA at low titre directed against PRL‐secreting cells in patients with autoimmune endocrine diseases in the absence of pituitary impairment, seems to be only a nonspecific marker of pituitary autoimmunity. A longitudinal study would be useful to clarify the relationship between the different pituitary cell involvement and the natural history of pituitary dysfunction in autoimmune hypophysitis.
Correlation between genotype, phenotype and sex of rearing in 111 patients with partial androgen insensitivity syndrome
Authors: Deeb A. , Mason C. , Lee Y. S. , Hughes I. A. 
Published: June 2005

SummaryObjective  Partial androgen insensitivity syndrome (PAIS) is a heterogeneous group of intersex disorders characterized by a typical perineoscrotal hypospadias/micropenis phenotype, and a normal androgen‐producing testis. Various mutations in the androgen receptor (AR) are known to cause PAIS. Phenotypic expression is widely variable and there are no agreed guidelines to determine the sex of rearing in individuals with borderline masculinization. We aimed to quantitatively assess the external genital phenotype in relation to AR genotype and sex of rearing and identify criteria that differentiate mutation positive (ARmt) from mutation negative (ARwt) PAIS patients.Patients and design  Cases with a diagnosis of PAIS were identified from the Cambridge Intersex Database. An external masculinization score (EMS) was used to quantify the degree of undermasculinization. Family history of AIS and details of the sex of rearing were recorded. Androgen binding was analysed in fibroblasts obtained from genital skin biopsies and mutational analysis of the AR was performed on genomic DNA extracted from peripheral blood. EMS and sex of rearing were compared in cases with similar mutations reported on the McGill International Database.Results  Two hundred and sixty‐three patients with PAIS were identified. Androgen receptor gene sequencing was performed in 111 patients. Twenty‐seven (24%) had mutations. Family history of AIS was present in 61 and 21% of ARmt and ARwt patients, respectively. The median EMS was 3 in both groups. The majority of ARmt patients had abnormal binding and there was a tendency to a higher median testosterone rise on hCG stimulation in ARmt (9·3 nmol/l) compared with ARwt patients (6·9 nmol/l). All patients with EMS of 4 or more were raised as male but there was an overlap of sex of rearing in patients with an EMS less than 4. A wide variation of EMS in relation to genotype and sex of rearing was observed.Conclusion  The phenotype in PAIS is extremely variable and is rarely predicted by the AR genotype. Apart from the family history, there are no specific criteria to differentiate ARwt from ARmt. Sex of rearing is not entirely dependent on the EMS. Cultural issues, other modifying genes and response to androgen trials might be influencing factors. Collaborative studies with uniform protocols are needed to investigate infants with PAIS. Documenting phenotype, surgical procedures and outcome criteria are necessary to enable decision‐making on the sex of rearing in patients with a lower range EMS.
Gender differences in the relation of insulin‐like growth factor binding protein‐1 to cardiovascular risk factors: a population‐based study
Authors: Undén Anna‐Lena , Elofsson Stig , Brismar Kerstin 
Published: June 2005

SummaryObjective  A possible involvement of insulin‐like growth factor‐I (IGF‐I) and its binding protein IGFBP‐1 in the pathogenesis of cardiovascular disorder has been suggested. However, few publications have addressed the gender differences in cardiovascular risk factors in relation to the IGF/IGFBP system. The aim of the present study was to study gender differences in the relationship between fasting serum levels of IGFBP‐1 and cardiovascular risk factors in a normal population of men and women.Design  Cross‐sectional study.Patients  A normal population of 273 men and women aged 20–74 years.Measurements  A medical examination was performed and blood drawn in the morning after subjects had been fasting overnight. Before the examination, they were asked to fill out a questionnaire concerning lifestyle and psychosocial factors.Results  Fasting IGFBP‐1 was lower in men than in women and was positively correlated to age in men but not in women. The men had in general a more disadvantageous cardiovascular risk profile than women, with several indicators of the metabolic syndrome: higher blood pressure and higher serum levels of total cholesterol, triglycerides, low density lipoprotein cholesterol (LDL‐C), plasma‐glucose and insulin, as well as lower IGFBP‐1. Women had lower physical activity, lower consumption of alcohol, and lower values on indicators of psychosocial and mental health but had a healthier diet. Our findings indicate that low circulating levels of IGFBP‐1 are associated with the well‐known risk factors of cardiovascular disease; however, the association showed a different pattern for men and women. In men we found a negative association with body mass index (BMI), insulin resistance and diastolic blood pressure, and a positive association with SHBG, cortisol and testosterone. For women low IGFBP‐1 appears in negative associations with BMI, waist–hip ratio (WHR), insulin resistance and testosterone, and in positive associations with SHBG and cortisol. Significant gender differences in the correlation with IGFBP‐1 are seen for testosterone, cortisol, SHBG, WHR and oestradiol. For HDL‐C and diastolic blood pressure the gender difference in correlation was at the limit of significance (P < 0·10).Conclusion  Low circulating levels of IGFBP‐1 are associated with the well‐known risk factors of cardiovascular disease; however, the association showed a different pattern for men and women. The most marked gender differences in the correlation with IGFBP‐1 are seen for testosterone, cortisol, SHBG, WHR, oestradiol, HDL‐C and diastolic blood pressure. Our study emphasizes the importance of separate analyses for men and women. The results presented are a step towards gaining a better understanding of the gender differences in cardiovascular disease and in the regulation of IGFBP‐1, though further prospective studies are needed.