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Biomedical subjects

V Alfaro

Publications and source records attributed to V Alfaro.

At least 19 recordsLinked to original sources
PubMed2022

Lurbinectedin, a selective inhibitor of oncogenic transcription, in patients with pretreated germline BRCA1/2 metastatic breast cancer: results from a phase II basket study.

BACKGROUND: Lurbinectedin, a selective inhibitor of oncogenic transcription, has shown preclinical antitumor activity against homologous recombination repair-deficient models and preliminary clinical activity in BRCA1/2 breast cancer. PATIENTS AND METHODS: This phase II basket multitumor trial (NCT02454972) evaluated lurbinectedin 3.2 mg/m2 1-h intravenous infusion every 3 weeks in a cohort of 21 patients with pretreated germline BRCA1/2 breast cancer. Patients with any hormone receptor and human epidermal growth factor receptor 2 status were enrolled. The primary efficacy endpoint was overall response rate (ORR) according to RECIST v1.1. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS) and safety. RESULTS: Confirmed partial response (PR) was observed in six patients [ORR = 28.6%; 95% confidence interval (CI) 11.3% to 52.2%] who had received a median of two prior advanced chemotherapy lines. Lurbinectedin was active in both BRCA mutations: four PRs in 11 patients (36.4%) with BRCA2 and two PRs in 10 patients (20.0%) with BRCA1. Median DoR was 8.6 months, median PFS was 4.1 months and median OS was 16.1 months. Stable disease (SD) was observed in 10 patients (47.6%), including 3 with unconfirmed response in a subsequent tumor assessment [ORR unconfirmed = 42.9% (95% CI 21.8% to 66.0%)]. Clinical benefit rate (PR + SD ≥ 4 months) was 76.2% (95% CI 52.8% to 91.8%). No objective response was observed among patients who had received prior poly (ADP-ribose) polymerase inhibitors. The most common treatment-related adverse events (AEs) were nausea (61.9%), fatigue (38.1%) and vomiting (23.8%). These AEs were mostly grade 1/2. The most common grade 3/4 toxicity was neutropenia (42.9%: grade 4, 23.8%: with no febrile neutropenia). CONCLUSIONS: This phase II study met its primary endpoint and showed activity of lurbinectedin in germline BRCA1/2 breast cancer. Lurbinectedin showed a predictable and manageable safety profile. Considering the exploratory aim of this trial as well as previous results in other phase II studies, further development of lurbinectedin in this indication is warranted.

Humans↗
PubMed2007

In vitro fertilization and development of OPU derived goat and sheep oocytes.

The recent upgrade in IVP technology seen in cattle can be adapted to embryo production in small ruminants to overcome limitations exhibited by surgical procedures on preserving the reproductive potential of donors and the efficiency of embryo production. The aim of the present study was to assess the current procedures used in cattle for the production of IVP embryos in goats and sheep based on laparoscopic-aided ovum pick-up (LOPU) supplied oocytes. Sexually matured goat and sheep donors were treated during the breeding season with FSH and subjected to laparoscopic-guided follicular puncture under general anaesthesia. The collected cumulus-oocyte complexes were matured in medium 199 and fertilized by frozen-thawed spermatozoa using Talp medium supplemented with heparin and oestrus-sheep serum. Cleaved ova were either cultured in sheep in vitro fertilization medium plus amino acids or transferred to sheep oviducts. Blastocyst rate, hatching rate and development rate up to term were used as markers of embryo function. The results obtained for goat and sheep involving 30 and 35 donors respectively (10 and 9 LOPU sessions) were 81.2% and 85.2% of oocyte collection rate; 88.3% and 98.6% oocyte incubation rate; 85.6% and 76.0% fertilization rate; 82.4% and 93.4% of cleavage rate; 50.0% and 61.5% IVP blastocyst rate; 42.1% and 45.5% blastocyst rate in oviducts; 73.0% and 66.7% embryo survival up to term, respectively. The results are comparable to those obtained in small ruminants and in bovines suggesting that requirements for embryo production and development are similar.

Animals↗
PubMed2006

Computer-assisted analysis of sperm motion in goats and its relationship with sperm migration in cervical mucus.

In vitro sperm migration in cervical mucus relates to sperm concentration at the utero-tubal junction and to in vivo fertilization performance in goats. The present study aimed to characterize, using Computer-Assisted Sperm Analysis (CASA), motility patterns depicted by buck sperm and their relation to the migration efficiency in homologous (goat) and heterologous (heifer) cervical mucus in vitro. Semen was collected from 23 sexually mature bucks from three breeds by artificial vagina and sperm were assessed for motility parameters with a Hobson Sperm analyzer following extension in Sperm Analysis Medium (SAM). To study the relationship between kinematics parameters and the ability of sperm to migrate in cervical mucus, in a first experiment, motility performance of buck sperm suspended in SAM was compared against seminal plasma. In a second experiment, kinematics parameters of sperm were characterized. In a third experiment, bucks with sperm that differed in specific motion parameters were compared for the ability of their sperm to migrate through goat and bovine cervical mucus collected at estrus. In a fourth experiment, ejaculates that were compared in their migration ability and were assessed simultaneously for their motility parameters. Overall, sperm suspended in SAM medium had better velocity and similar linearity and lateral head displacement than those suspended in seminal plasma; furthermore, caprine sperm swam relatively fast (relative to bovine and ovine sperm), following a very linear trajectory. Under the conditions used, velocity parameters, linearity and lateral head displacement seemed to be related to sperm migration efficiency in homologous mucus but not in bovine cervical mucus.

Animals↗
PubMed2005

Specification of laboratory animal use in scientific articles: current low detail in the journals' instructions for authors and some proposals.

The scientific article communicates results of research to other investigators; therefore, it must contain a complete description of the experiment to help other researchers when designing their future investigations. However, poorly detailed data on laboratory animal use is given in published articles. Despite the well-known and important contribution of the International Committee of Medical Journal Editors (ICMJE) to standardize scientific writing and submission of manuscripts to biomedical journals, no specific instructions on the reporting of animal use are given in the ICMJE Uniform Requirements and, therefore, most journals do not detail this to the authors. Individual efforts from groups like the Working Committee for the Biological Characterizations of Laboratory Animals, the Boyd Group, or the Committee on Publication Ethics are commendable. These contributions should be incorporated into the ICMJE Uniform Requirements and, later, into the Instructions for Authors of peer-reviewed journals. This would be the only efficient way to instruct authors on how to report laboratory animal use in their submitted manuscripts. The present article relates some proposals for helping authors when reporting animal use in scientific articles. These proposals are not only based on previous guidelines for animal specifications, but also on Instructions for Authors from journals specialized in Laboratory Animal Science. These proposals are classified into major and minor issues, and they are located in the corresponding parts of the article, as defined by the Introduction, Methods, Results, and Discussion (IMRAD) method.

Animal Experimentation↗
PubMed2004

Role of histamine and platelet-activating factor in allergic rhinitis.

This review is focused on the effects of histamine and platelet-activating factor (PAF) in allergic rhinitis and the plausible implications for therapy. Rhinitis is defined as a heterogeneous disorder resulting from an IgE-mediated reaction associated with nasal inflammation of variable intensity. Two phases of response are triggered by an IgE/allergen cross-linking event: the first is the release of preformed mediators such as histamine or interleukins from mast cells and basophils; the second begins when cells start producing lipid-derived mediators. One of these mediators is PAF. Apart from leukotrienes, PAF is perhaps the most potent inflammatory mediator in allergic rhinitis for inducing vascular leakage, a response that may contribute to the appearance of rhinorrhea and nasal congestion.

Animals↗
PubMed2004

Intestinal ischemic preconditioning: less xanthine accumulation relates with less apoptosis.

Ischemic preconditioning has shown to reduce apoptosis in the intestinal mucosa during ischemia/reperfusion. This study evaluated if the decrease of apoptotic events found during preconditioning could be related with a reduction of the substrate (i.e., xanthine/hypoxanthine) available for xanthine oxidase (XO). Animals were randomly assigned to the following study groups: C, control; I/R, ischemia/reperfusion; P+I/R, ischemic preconditioning; P+I/R+H/X, ischemic preconditioning plus hypoxanthine/xanthine, and P+I/R+H/X+Allo, ischemic preconditioning plus hypoxanthine/xanthine plus allopurinol. Caspase-3 activity, DNA fragmentation and TUNEL staining increased in the I/R group compared to control. Ischemic preconditioning (P+I/R group) was able to reverse these apoptotic variables to a level similar to that of control rats. The addition of hypoxanthine/xanthine to rats subjected to ischemic preconditioning (P+I/R+H/X group) showed the highest apoptotic activity; however, further addition of allopurinol (P+I/R+H/X+Allo group) decreased significantly apoptotic activity and events. In conclusion, intestinal ischemic preconditioning is able to reduce apoptosis during the following sustained ischemia/reperfusion event because of a reduced accumulation of xanthine/hypoxanthine nucleotide.

Allopurinol↗
PubMed2003

Exogenous adenosine enhances caspase-3 activity in warm renal ischaemia.

Renal injury due to ischaemia/reperfusion (I/R) leads to impaired renal function. One of the essential pathological changes thereby is cell death due to apoptosis. This study investigated the effect of adenosine administration on caspase-3 (C3) activity and expression during warm renal ischaemia in rat kidney and the role of nitric oxide (NO) as a mediator of the adenosine-induced effect. The following experimental groups were studied: control, ischaemia, ischaemia with adenosine administration, ischaemia with adenosine and N-nitro- l-arginine methyl ester (L-NAME) treatment and ischaemia with NO donor administration. C3 activity was measured and its protein expression determined by Western blot analysis. Supplementation of adenosine or NO during ischaemia increased C3 activity and protein expression but the effect of adenosine was reversed in rats treated with L-NAME. We conclude that adenosine increases C3 activity through an NO-dependent mechanism.

Adenosine↗
PubMed2003

Nucleotides modulate renal ischaemia-reperfusion injury by different effects on nitric oxide and superoxide.

1. The present study investigated the effects of kidney ischaemia duration on nitric oxide (NO) and superoxide (O2-) generation at reperfusion and the role of xanthine and adenosine as mediators of NO/O2- generation. 2. The effect of the duration of ischaemia on renal nucleotide levels was studied in two ischaemic groups (10 and 30 min). The role of adenosine and xanthine was studied in ischaemic-reperfused groups (subjected to 10 and 30 min ischaemia and 60 min reperfusion). 3. Tissue levels of adenosine decreased significantly after 30 min ischaemia, whereas xanthine/hypoxanthine levels increased concomitantly with renal dysfunction and histological damage. 4. Nitric oxide production increased significantly after 10 min ischaemia and 60 min reperfusion, whereas lipoperoxidation increased significantly after 30 min ischaemia and 60 min reperfusion. The administration of theophylline (40 mg/kg, i.p.) reversed the early increase in NO production. 5. Xanthine supplementation decreased renal function and increased lipoperoxidation. 6. In conclusion, NO/O2- production and the subsequent renal injury/dysfunction may be modified by changes in the adenosine and xanthine levels of the injured kidney, although the present data show a significant in vivo role only for xanthine.

Adenosine↗
PubMed2002

Extracellular pH affects inflammatory cell production of superoxide and nitric oxide.

Previous research has described how high cellular metabolism creates an acidic environment in inflammatory cells during respiratory burst. The aim of our work was to describe the acid-base dependence of exudate in superoxide (O2.-) and nitric oxide (NO.) generation by inflammatory cells from a carrageenan-granuloma. Although the carrageenan solution was alkaline (pH 7.74 when equilibrated with air) the exudate showed an acidification that stabilised at around 7 units of pH. A notable hypercapnia, but not hypoxia, was found in the exudate at up to 24 h. The effect of extracellular acidosis on O2.- and NO. production by inflammatory cells was also studied. The maximum O2.- production and the lowest levels of NO. were found at pH 7, which was closer to the pH of the granuloma-pouch. These results suggest that experiments with inflammatory cells ex vivo should be carried out at an identical pH to that found in vivo in order to reproduce the physiological mechanisms of free radical generation during inflammatory processes.

Animals↗
PubMed2001

CO2 in static mesenteric venous blood during intestinal ischemia and ischemic preconditioning in rats.

During intestinal ischemia, CO2 accumulates in tissue as a result of bicarbonate buffering of anaerobic acid generation. Previous studies have shown that nitric oxide (NO) generated during ischemic preconditioning acts as a glycolytic modulator, thus decreasing tissue lactate production. We studied if ischemic preconditioning induces NO-dependent changes in static mesenteric venous blood Pco2 values and CO2 accumulation during intestinal ischemia. Superior mesenteric venous (smv) acid base variables were studied in 4 groups of rats: a control group (C), an ischemic (90-min period of flow arrest) group (I), an ischemic group subjected to previous ischemic preconditioning (P), and an ischemic group subjected to previous ischemic preconditioning in which nitric oxide synthase (NOS) was inhibited by N-nitro-L-arginine methyl ester (L-NAME) administration (P+N). Preconditioning induced acidosis in smv blood during reperfusion before ischemia, but this effect was counteracted by L-NAME. Group P showed the lowest values of end-ischemic tissue lactate, smv blood CO2 accumulation, and LDH in perfusate, whereas group P+N showed the highest level of LDH in perfusate but the lowest end-ischemic smv blood Pco2 and acidity. We conclude that lower ischemic CO2 accumulation in static smv blood, but not lower end-ischemic Pco2, was related with the protective effect of ischemic preconditioning in our rat model. Thus, the use of stagnant smv blood Pco2 as an indicative of intestinal dysoxia can lead to misinterpretations if a broader acid-base picture is not considered.

Anaerobiosis↗
PubMed2000

The clinical uroselectivity of alfuzosin is not significantly affected by the age of patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia.

OBJECTIVE: To assess the effect of the age of patients with benign prostatic hyperplasia (BPH) on the clinical uroselectivity of alfuzosin during general medical practice. PATIENTS AND METHODS: The present national, multicentre, open-labelled, observational study involved 4018 Spanish outpatients with BPH, i.e. showing lower urinary tract symptoms (LUTS) suggestive of benign prostatic obstruction. The patients received sustained release (SR) alfuzosin, 5 mg twice daily, for 2 months. The primary efficacy criteria were symptomatic improvements, as assessed by the International Prostate Symptom Score (IPSS) and quality of life (QoL) index. Safety was assessed by monitoring cardiovascular data and adverse events. RESULTS: The patients were divided into four age groups, i.e. < 56, 56-65, 66-75 and > 75 years. All groups of patients showed a mean IPSS decrease of 11-12 (55.8-65.4% from baseline) at the end of the study, while the QoL decreased by 2-3 points (55.6-63.6% from baseline). There were no relevant effects of age on the efficacy of the treatment. Moreover, alfuzosin was well tolerated independently of the age of the patient; 1.2% of the patients enrolled withdrew because of adverse events. The qualitative distribution of vasodilatory/nonvasodilatory adverse events was similar in all age groups. The incidence of asymptomatic orthostatic hypotension was low (0.58%) and not affected by the age of the patients. CONCLUSION: This study confirms that the clinical uro-selectivity of SR-alfuzosin, already described in ran-domized controlled studies, is not significantly affected in clinical practice by the age of the patients. This is considered particularly relevant to the characteristics of patients with BPH, as they are mostly elderly men.

Adrenergic alpha-Antagonists↗
PubMed2000

Safety and efficacy of sustained-release alfuzosin on lower urinary tract symptoms suggestive of benign prostatic hyperplasia in 3,095 Spanish patients evaluated during general practice.

OBJECTIVES: This general practitioner-run study assess the security as well as the efficacy and impact on health-related quality of life of a sustained-release (SR) form of alfuzosin in Spanish patients suffering from lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). MATERIAL AND METHODS: 3,095 patients with symptomatic BPH were enrolled into a national, multicentric, open, phase IV observational study. The period of active treatment studied (5 mg, twice daily) was 60 days. Safety was assessed by monitoring blood pressure and spontaneous adverse events. Symptoms were assessed using a validated Spanish International Prostate Symptom Score (I-PSS). Impact of symptoms on health-related quality of life was assessed using the quality of life index (L). RESULTS: 101 adverse events were reported in 82 patients (2.6%). 28 adverse events (2.6%) were classified as severe. 49 patients (1.6%) dropped out of the study due to adverse events but only 17 of these patients (0.5%) showed adverse events related to vasodilation. Incidence of postural events (vertigo, postural hypotension/hypotension, headache and dizziness) was low (55 patients, 1.8%) and effects on sexual function were found not significant: no retrograde ejaculation was reported and only 1 patient (0.03%) showed impotence. Blood pressure or heart rate showed no clinically significant changes. All the I-PSS scores decreased significantly during the treatment with alfuzosin, improvement being excellent in 60% of the patients. Symptomatic improvement was associated with a significant improvement in health-related quality of life. CONCLUSIONS: This large study conducted during general practice on Spanish BPH patients confirms the efficacy on LUTS and good safety profile of SR alfuzosin, especially its low incidence of postural symptoms and no deleterious effect on sexual function.

Adrenergic alpha-Antagonists↗
PubMed2000

Age-stratified analysis of I-PSS and QoL values in spanish patients with symptoms potentially related to BPH.

OBJECTIVE: The main goal of the present study was to determine age-related symptom changes using a validated Spanish International Prostate Symptom Score (I-PSS) and quality of life index (QoL) in Spanish patients with symptomatic benign prostatic hyperplasia (BPH). METHODS: A total of 2,875 patients with the clinical diagnosis of symptomatic BPH were evaluated. Data were collected during current medical practice in a national study. Patients were excluded if they had any previous prostate operation or suspicion of prostate cancer. I-PSS was self-administered and compared with the physician's global impression. RESULTS: I-PSS symptoms, both voiding and storage symptoms, increased significantly with age (p<0.0001) as well as QoL (p<0.0017). A change in the I-PSS categories (minor, moderate and severe) was found with age, increasing severe symptomatic patients in the oldest groups. A significant correlation was found between I-PSS and QoL (r = 0.49, p<0.001), being this relationship linear and not significantly influenced by age. CONCLUSIONS: This study confirms reliable results using a validated Spanish I-PSS in a large national representative sample of Spanish patients with BPH symptoms. The age-stratified analysis showed that the natural progression of BPH with age was related to an increased symptomatology and bothersomeness, well reflected by increases in the I-PSS and QoL values. Nevertheless, the effect of symptomatology on quality of life was not strongly influenced by the age of the patient.

Age Factors↗
PubMed2000

Acid-base analysis during experimental anemia in rats.

The present study evaluated the acid-base status of anemic rats by using two approaches of acid-base analysis: one based on the base excess (BE) calculation and the other based on Stewart's physicochemical analysis. Two sets of experimental data, derived from two different methods of inducing anemia, were used: repetitive doses of phenylhydrazine (PHZ) and bleeding (BL). A significant uncompensated respiratory alkalosis was found in both groups of anemic rats. BE increased slightly, whereas strong ion difference ([SID]) and weak acid buffers ([A(TOT)]) remained unchanged in anemic rats. The reasons for the absence of compensation for hypocapnia and the differences in the behaviour of acid-base variables are discussed. BE increase was considered paradoxical; its calculation was affected by the experimental conditions and BE had little physiological relevance during anemia. The absence of metabolic renal compensation in anemic rats could be due to a lower pH in the kidney due to anemic hypoxia. Finally, the changes in buffer strength related to low Hb and low P(CO2) might influence plasma [SID] through counteracted shifts of strong ions between erythrocytes and plasma, finally resulting in unchanged [SID] during anemia.

Acid-Base Imbalance↗
PubMed1999

Modification of glyceraldehyde-3-phosphate dehydrogenase in response to nitric oxide in intestinal preconditioning.

BACKGROUND: Previous studies have demonstrated that intestinal preconditioning is triggered by an initial increase in nitric oxide synthesis. This confers resistance to the organ in face of a subsequently sustained period of ischemia-reperfusion. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a key enzyme in the glycolytic cascade that could be modulated by nitric oxide. The purpose of the present study is to evaluate a possible inhibitory effect on intestinal GAPDH by the nitric oxide generated during preconditioning. This could lead to a reduction of lactate accumulation during subsequent ischemia. METHODS: GAPDH activity was measured after intestinal preconditioning, and the effect of nitric oxide synthase inhibition was evaluated. RESULTS: Preconditioning induced a significant, but transient, decrease in GAPDH activity. This effect appears to be correlated with a reduced amount of lactate accumulation during ischemia. Inhibition of nitric oxide synthesis reversed these changes. In addition, increased synthesis of nitric oxide was detected after preconditioning. CONCLUSIONS: In summary, this study indicates that nitric oxide generated during ischemic preconditioning could act as a glycolytic modulator during subsequent ischemia, through its effect on GAPDH activity.

Animals↗
PubMed1999

Acid-base disturbance during hemorrhage in rats: significant role of strong inorganic ions.

The present study tests the hypothesis that changes in the strong inorganic ion concentrations contribute significantly to the acid-base disturbance that develops during hemorrhage in the arterial plasma of rats in addition to lactate concentration ([Lac-]) increase. The physicochemical origins for this acid-base disorder were studied during acute, graded hemorrhage (10, 20, and 30% loss of blood volume) in three groups of rats: conscious, anesthetized with ketamine, and anesthetized with urethan. The results support the hypothesis examined: strong-ion difference (SID) decreased in the arterial plasma of all groups studied because of an early imbalance in the main strong inorganic ions during initial hemorrhagic phase. Moreover, changes in plasma [Lac-] contributed to SID decrease in a later hemorrhagic phase (after 10% hemorrhage in urethan-anesthetized, after 20% hemorrhage in ketamine-anesthetized, and after 30% hemorrhage in conscious group). Inorganic ion changes were due to both dilution of the vascular compartment and ion exchange with extravascular space and red blood cells, as compensation for blood volume depletion and hypocapnia. Nevertheless, anesthetized rats were less able than conscious rats to preserve normal arterial pH during hemorrhage, mainly because of an impaired peripheral tissue condition and incomplete ventilatory compensation.

Acid-Base Equilibrium↗
PubMed1997

Components of the blood acid-base disturbance that accompanies urethane anaesthesia in rats during normothermia and hypothermia.

1. We have studied the components of the metabolic acidosis that accompanies urethane anaesthesia in rats, both with and without the hypothermia that results from this anaesthesia. 2. Acid-base disturbances were analysed with an approach based on Stewart's analysis of acid-base chemistry. 3. The pH fall in the blood of normothermic anaesthetized rats (body temperature Tb) = 37 degrees C) was related to increases in plasma anions (lactate and [Cl-]), which decreased the strong ion difference ([SID]), as well as to increase the weak acid buffers due to increases in albumin. 4. A stronger metabolic acidosis was found in the blood of rats with hypothermia induced by urethane (Tb = 32 degrees C). Although plasma lactate was unchanged in hypothermic rats, [SID] decreased due to alterations in the plasma ionic balance. The metabolic acidosis found in hypothermia was also associated with increased weak acid buffers due to increases in albumin and inorganic phosphate. Further to hyperphosphataemia, signs of acute renal disfunction, such as increases in plasma [Mg2+] and blood urea nitrogen were found. Plasma retention of endogenous acids together with the retention of acid end-products of the metabolism of urethane because of acute renal failure may have contributed to strengthening the fall in pH and [HCO3-] found in urethane-induced hypothermic rats.

Acidosis↗