1,721,017 research outputs found
Cerebral vascular reactivity and cognitive performance in patients with extracranial asymptomatic carotid stenosis
No full textBackground: Preliminary studies have reported cognitive dysfunction
in unilateral asymptomatic carotid stenosis (ACS). Impaired
cerebral hemodynamic status measured by cerebrovascular reactivity
has been associated with cognitive dysfunction in unilateral
ACS.
Aims: (1) To evaluate cognitive performance in bilateral ACS compared
to unilateral ACS and healthy subjects and (2) to explore the
relationship between cognitive performance and cerebral hemodynamic
status in bilateral ACS.
Methods: Asymptomatic patients with ultrasound evidence of bilateral
or unilateral ACS (60 %-99 % diameter reduction) were
prospectively collected. Healthy subjects (HS) comparable for
demographics and vascular risk profile served as controls. A neuropsychological
investigation included phonemic and categorical
Verbal Fluency (VF) tests to explore the left hemisphere and Colored
Progressive Matrices (CPM), and Complex Figure Test Copy (CFTC)
tests to explore the right hemisphere. Cerebrovascular reactivity
(CVR) to hypercapnia using the transcranial Doppler (TCD) based
breath-holding index (BHI) test was performed in each subject.
Impaired CVR was defined as a BHI\0.69. Generalized linear
multivariate and univariate models were employed to evaluate the
mean difference on left and right cognitive test abilities in bilateral
ACS patients with left and right preserved or impaired CVR. Vascular
risk factors, education years, mini-mental status examination
(MMSE), and current medications were included as covariates.
Results: 333 consecutive subjects were included: 126 bilateral
ACS; 73/75 left/right unilateral ACS; 56 HS; mean age: 70 ± 3.78
years; males: 65 %; education years: 10.3 ± 3.7; MMSE score:
26.7 ± 1.27. Bilateral and unilateral ACS patients showed significantly
lower scores in all cognitive tests compared to HS (p\0.05).
In the multivariate analysis, among bilateral ACS an impaired CVR in
the right side was associated with a significantly reduced CPM score:
from an estimated mean of 32.6 [95 % Confidence Interval (CI):
29.8–35.4) to 23.0 (95 % CI: 20.2–25.8) and the CFTC score from
34.7 (95 % CI: 32.0–37.4) to 26.0 (95 % CI: 23.3–28.7). Similarly, an
impaired CVR on the left side was associated with a reduced phonemic
VF score: 13.5 (95 % CI: 11.2–15.8) to 7.5 (95 % CI: 5.4–9.7)
and categorical VF score from 21.1 (95 % CI: 18.1–24.1) to 12.3
(95 % CI: 9.5–15.1). All comparisons were statistically significant
(p\0.05).
Conclusions: Patients with unilateral or bilateral ACS are more likely
to suffer cognitive dysfunction compared to healthy controls.
Impaired CVR predicts the development of cognitive dysfunction in
bilateral ACS. A non-invasive assessment of CVR using the TCDbased
BHI test may contribute to a more comprehensive risk stratification
in these patients
Treatment of hypothalamic infertility with pulsatile GN-RH administration.
No full textIn this study the Authors have obtained an ovulatory response using intravenous Gn-RH treatment in four patients with hypothalamic hypogonadotropic amenorrhea. The Gn-RH was administered in a pulsatile manner with a small portable autoinfusion pump (Autosyringe, Inc., Hooksett). The ovarian follicular maturation, as it appears from the pelvic echography, was perfectly similar to that observed in a spontaneous ovulatory cycle. Endocrine picture by serial determination of gonadotropin; prolactin, estradiol and progesterone concentrations showed hormone values to be in the normal range. During the therapy no complications were observed; at the present time no pregnancy has occurred
Polycystic ovary syndrome: long-term evolution.
No full textA study was made of the long-term evolution of 64 women with PCO in order to identify the clinical and/or endocrine alterations that may modify the prognosis of each case. The patients were divided into two groups: Group A, where at the conclusion of the observation period disorders were present, and Group B, where they were not. A comparison between the clinical and endocrine data obtained from the two groups at the first observation showed only one significant difference, concerning the time of onset of menstrual irregularities; these coincided with the menarche in only 57.6% of the cases in Group A, but in 94.7% of those in Group B
A new method for free testosterone assay: clinical evaluation.
No full textThe Authors propose a new direct method for the determination of free Testosterone (F. Te).
Our study was made following this method: 1) on a control group composed of 12 healthy
men and 21 healthy women, and 2) on a group of 29 patients suffering from Polycystic Ovary
Syndrome (PCOS) with clinical signs of hyperandrogenism. This pathological group
presented acne and hirsutism in 95% of the cases. The Authors demonstrate how the
determination of F
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Fibrocystic Disease of the Breast Associated with Pituitary‐Ovarian Dysfunction: Results of Treatment with Bromocriptine
No full textCardiovascular risk factors and carotid stenosis predict cerebral haemodynamic impairment in Alzheimer’s Disease
No full textAbstract: Alzheimer’s Disease (AD) is the most common form of
progressive dementia among internistic patients. Many hypotheses
have been postulated for AD pathogenesis, and there is a growing but
conflicting evidence about a vascular theory (1,3). Recently, we found
a significant correlation between extracranial carotid atherosclerosis,
intracranial vascular reactivity and mini-mental state examination
(MMSE) impairment over a 12-months observation in a cohort of 442
AD patients (2).
Aims: Aim of this study was to evaluate the correlation between
intracranial vascular reactivity index (breath-holding index, BHI),
extracranial carotid atherosclerotic involvement and classical cardiovascular
risk factors, as demographic characteristics, smoking,
hypertension, diabetes and dyslipidemia in a cohort of patients
affected by clinically defined AD.
Patients and Methods: We enrolled 745 consecutive patients followed
by the dementia ward of our University Hospital (A.O.U.
Ospedali Riuniti, Ancona). Each patient underwent a standardized
interview about clinical history, neuropsycological evaluation,
extracranial echo-color Doppler ultrasound and transcranial doppler
(TCD), testing BHI for each side. We synthesized each
classical risk factor and sex into a dichotomous variable; the
number of risk factors affecting a single patient were collected into
an ordinal variable (ranging from 0 risk factors to 4 risk factors);
extracranial echo-color Doppler result was expressed into an
ordinal variable, ranging from ‘‘no stenosis’’ to ‘‘bilateral haemodynamic
stenosis’’. Only hemodynamically significant ([60% of
the internal carotid lumen) stenoses were considered. MMSE
scores, corrected for age and sex, were collected as continuous
variables. Breath-holding index, calculated by dividing the percent
increase in mean flow velocity occurring during breath-holding by
the length of time (in seconds) subjects hold their breath after a
normal inspiration, was synthesized both as a dichotomous variable
(\0.69, pathologic, [0.69, normal) (3) and as an ordinal variable
(normal, monolateral pathologic and bilateral pathologic). Statistical
analysis was conducted with two ordinal regression models,
one considering BHI as dichotomous, the other considering BHI as
ordinal. Both models included the classical risk factors, the synthetic
variable for the number of risk factors and the ordinal
variable for extracranial echo-color Doppler results. Results have
been weighted by MMSE, age and sex. Ordinal regression was
calculated with SPSS 13.0 for Windows systems. Probability of
each event was calculated as 1/[1 + (ea-bx)], being a the level
threshold and bx the factor level.
Results: The probability of a normal BHI in AD patients
decreased proportionally with the increase of the number of
vascular risk factors, from 95% in patients with no risk factor to
21% of patients with four risk factors (Fig. 1, p\0.05). Extracranial
echo-color Doppler ultrasound could also predict a
pathological BHI: the probability of a normal BHI decreased from
73% among patients without hemodynamically significant stenosis
to 21% in patients with bilateral stenosis (Fig. 2, p\0.05). Each
vascular risk factor was also associated with an increase of the
risk of developing a pathological (monolateral or bilateral) BHI
(p\0.05).
Discussion: AD is a complex disease, and its pathogenesis, still uncleared,
could be related to microvascular alterations in a favourable
genetic background. Hypertension, diabetes, smoking and dyslipidemia
have already been associated to AD and its progression (1). Both
BHI and extracranial vessels involvement can predict a worse outcome
at 12 months in MMSE, independently from specific treatment
and risk factors presence (2). BHI is a suitable index for cerebral
hemodynamics status, and its alteration could express the final pathway
of vascular derangement in AD. Classical risk factors and
extracranial haemodynamic impairment could act on intracranial
circulation initiating and maintaining the cascade of events responsible
of AD progression
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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