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Biomedical subjects

P Alía

Publications and source records attributed to P Alía.

7 recordsLinked to original sources
PubMed2006

Profile, mean residence time of ACTH and cortisol responses after low and standard ACTH tests in healthy volunteers.

OBJECTIVE: No consensus exists until now about the suitable dose of tetracosactin in the ACTH stimulation test for detecting adrenal insufficiency. Our aim was to characterize both the ACTH(1-24) and the cortisol profiles after standard high-dose test (250 microg) (HDT) and low-dose test (1 microg) (LDT) in healthy subjects in order to provide a deeper knowledge about the relationship between stimulus and response. DESIGN AND PATIENTS: ACTH tests were performed in 10 healthy volunteers (five men, five women) with at least 1 week of difference. MEASUREMENTS: Plasma ACTH(1-24) and ACTH(1-39) and serum cortisol were measured before tetracosactin i.v. injection and at 5, 15, 30, 45, 60, 75 and 90 min after stimulus. Area under the curve (AUC) of ACTH(1-24) and cortisol, as well as mean residence time (MRT) for ACTH(1-24) were calculated in both tests. RESULTS: Elimination of ACTH(1-24) was faster in HDT than in LDT (MRTs of 0.14 vs 0.37, respectively, P = 0.008), but plasma concentrations were higher up to 60 min cortisol production in HDT reaching a higher maximum concentration (Cmax: 1144 vs 960 nmol/l) but delayed in time (75 vs 52.5 min). No significant relationship was observed between AUC or Cmax of ACTH(1-24) and AUC, Cmax and increment of cortisol in any of the tests. However, a negative correlation of basal cortisol values was observed with relative cortisol increment (HDT: r = 0.77 P = 0.009; LDT: r = 0.94 P < 0.0001), but not so with Cmax (HDT: r = 0.22 P = 0.55; LDT: r = 0.57 P = 0.09). CONCLUSIONS: The elimination rate of ACTH in healthy volunteers was significantly lower in LDT than in HDT, but cortisol production rate appears to be identical in both tests, so that a maximum adrenal stimulation seems to exist. The use of LDT may be more adequate, although data from patients need studying.

Adrenal Cortex Function Tests↗
PubMed2005

Association between ACE gene I/D polymorphism and clinical presentation and prognosis of sarcoidosis.

Serum angiotensin converting enzyme (SACE) concentration is considered a marker of sarcoidosis activity. This concentration is influenced by an insertion/deletion (I/D) polymorphism of the ACE gene, such that SACE levels follow the pattern DD>ID>II. The aim of our work was to study the relationship between I/D polymorphism and susceptibility to sarcoidosis, as well as the relation between this polymorphism and the clinical presentation and evolution of the disease in 177 sarcoidosis patients. A group of 104 individuals without sarcoidosis was included as control. Genotyping was done by a polymerase chain reaction (PCR) method, and SACE concentration at diagnosis was determined by a kinetic method. No differences were observed in genotype or allele distributions between patients and controls, nor between patients considering the type of presentation (Löfgren versus non-Löfgren) and evolution of the disease (acute versus chronic). As reported for healthy populations, SACE concentrations followed the pattern DD>ID>II in sarcoidosis patients, but significant differences between genotypes existed only in the Löfgren group (p = 0.003) and in acute patients (p = 0.02). SACE concentrations at diagnosis were lower in acute patients (p = 0.05) and in Löfgren's syndrome (p = 0.04), but this seemed to occur only in ID individuals (p = 0.02 and p = 0.01, respectively). No relation was thus found between I/D polymorphism and susceptibility to sarcoidosis, but ACE I/D genotyping may improve the assessment of disease activity, both at diagnosis and during the follow-up of treated and untreated patients.

Female↗
PubMed1998

Detection of differentially expressed gelatinase A in metastatic and non-metastatic subpopulations of tumor cells by target RNA arbitrarily primed polymerase chain reaction (TRAP-PCR).

We have developed a novel procedure called Targeted RNA AP-PCR (TRAP-PCR) to quantitatively measure specific mRNA expression. The target mRNA is reverse transcribed using a specific primer and PCR is performed under low stringency conditions to generate a rich fingerprint-type band pattern. In this situation multiple sequences are coamplified with the targeted sequence. The amplification is carried out in a competitive fashion and is, in consequence, quantitative. We have applied this technique to determine Gelatinase A (Gel A) mRNA expression in the MXT mouse mammary carcinoma system. TRAP-PCR analysis using primers for Gel A produced a reproducible fingerprint including one major band whose identity was confirmed to be Gel A cDNA. Highly metastatic MXT subclones show an increased Gel A expression. Results were confirmed by Northern blot and protein activity (gelatin zymography). TRAP-PCR is a simple, sensitive and specific technique to comparatively quantify mRNA expression and requires less template than conventional methods.

Animals↗
PubMed1996

[Relationship between blood levels of sex hormone binding globulin, testosterone levels in blood and saliva and body morphology in premenopausal women].

BACKGROUND: The concentrations of the globulin binding of sexual hormones (GBSH) and serum and saliva testosterone were studied, as well as the free testosterone index (FTI), in a group of 75 premenopausic women of 42 years of age. These concentrations were correlated with the body mass index (BMI) and the relationship between the waist and hip perimeters (WHI) as an index of body fat distribution. MATERIAL AND METHODS: Anthropometric measurements were performed in all the women studied. The BMI was used to classify the women as obese or not obese, while the WHI was used to classify fat distribution as android or gynoid type. The hormone determinations were carried out by radioimmunoassay and the GBSH by fluorescence immunoassay. RESULTS: A significant positive correlation was observed between FTI and BMI (p = 0.024) and a negative correlation was seen between GBSH and WHI (p = 0.024). A significant decrease was found in the GBSH levels in obese women with respect to those who were not obese (p = 0.025) and between those with android fat distribution versus gynoid fat distribution (p = 0.032). CONCLUSIONS: The modifications observed in the concentrations of the globulin binding sexual hormone in obese premenopausic women and the absence of the same in the free testosterone indexes may be explained because of other steroids such as androstenodiol and dehydrotestosterone are elevated. The measurement of globulin binding sexual hormone concentrations may be an early marker of alteration in the androgenic status in obese women.

Adult↗
PubMed1994

Analytical goals for rectilinear calibration functions.

Analytical goals for rectilinearity based on within-subject biological variation have not yet been advocated. On the other hand, the statistical tests to evaluate rectilinearity may be too restrictive for clinical purposes. If rectilinearity of the least-squares regression is rejected by the statistical test used, we propose to compare the systematic error introduced using such a regression line as the calibration function, with the allowable total error. Since total error ideally should be less than the within-subject biological coefficient of variation (C.V.Bw) the goal for rectilinearity we propose is that the maximum allowable systematic relative error produced by the calibration function (LoRi) when a lack of rectilinearity really occurs is: LoRi < C.V.Bw -1.96 C.V.M, where C.V.M is the between-run metrological coefficient of variation of the measurement procedure, corresponding to the value of concentration under study.

Algorithms↗