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Biomedical subjects

M F López

Publications and source records attributed to M F López.

11 recordsLinked to original sources

Development of a new disease-specific quality-of-life questionnaire to adults living with haemophilia.

A haemophilia-specific health-related quality-of-life questionnaire (named 'Hemofilia-QoL') was developed to assess quality-of-life in adults with haemophilia, and was psychometrically tested. Seventy-three interviews with haemophilia patients and health care professionals were used to generate the items included in the questionnaire, and expert ratings on the items formulated were used to screen them for potential omission. This was followed by psychometric testing in a sample of 35 patients. Preliminary psychometric testing of the revised questionnaire version, which contains 10 domains (physical health, physical role, joint damage, pain, treatment satisfaction, emotional role, mental health, social support), showed acceptable reliability (alpha = 0.94 for the Hemofilia-QoL total score) and validity, and this will be examined in a subsequent study with a larger patient sample.

Adolescent↗

Immune tolerance treatment in haemophilia patients with inhibitors: the Spanish Registry.

We present a retrospective study of immune tolerance treatment (ITT) carried out in 42 Spanish haemophiliac patients. Most of the patients were high responders (39/42), with a median maximum titre of 67 Bethesda units (BU) (range 6-2984). The median inhibitor titre at the start the ITT was 11 BU (range 1-256 BU) and the median age of the patients was 7 years (range 0-57). The mean factor dosage was 140 IU kg bodyweight(-1) day(-1) (range 25-500). In most of the ITTs, plasma-derived factor concentrate of intermediate and high purity was used. The inhibitor was eradicated in 26/38 (68%) of the patients who completed the treatment and two patients changed their status from high to low responders. Multivariate logistic regression analysis showed that three significant variables were associated with the highest probability of success: (i) the use of low factor doses for ITT (< or = 100 IU kg(-1) day(-1); P = 0.0106; 95% CI 0.000289-0.342); (ii) a titre of < 10 BU at start of ITT (P = 0.0286; 95% CI 0.00253-0.7189) and (iii) a lower maximum titre (P = 0.0214; 95% CI 0.98-0.9994).

Actuarial Analysis↗

Interactions between perinatal and neonatal associative learning defined by contiguous olfactory and tactile stimulation.

Tactile stimulation of the neonate, as performed by the mother during and after delivery, has been described as an effective unconditioned stimulus during early ontogeny (Leon, 1987; Ronca & Alberts, 1994). The present experiments examined the interaction between perinatal and neonatal learning determined by the explicit association between alcohol odor and vigorous body stimulation of the perinatal organism. In Experiment 1, rat fetuses were exposed to either alcohol or saline 10 min prior to cesarean delivery. The alcohol administration procedure here employed was sufficient to provide sensory contamination of the amniotic fluid but avoid fetal alcohol intoxication. Pups in the two prenatal treatments later experienced the smell of alcohol, tactile stimulation, or both stimuli explicitly paired or unpaired. Other postnatal groups were composed of pups that had no explicit experience with either experimental stimulus. Pups subjected to alcohol odor in utero displayed more overall motor activity in response to that odor than saline controls. The increased motor responses were further potentiated in pups that experienced additional postnatal alcohol odor paired with tactile stimulation. In Experiment 2, pups were exposed to alcohol in the amniotic fluid 10 or 30 min prior to birth. As previously demonstrated the memory acquired in utero appears highly dependent upon contingency between exposure to this particular scent and delivery procedures. Pups in both prenatal treatment groups were then exposed to alcohol odor paired or unpaired with tactile stimulation. Some control animals received no further experience with either stimuli. Those pups exposed to alcohol odor paired with tactile stimulation both pre- and postnatally later showed maximum motor activity elicited by the odor of alcohol. The results support the notion of fetal associative learning comprising alcohol's chemosensory cues and behaviorally activating stimuli. Furthermore, the conditioned response under analysis is potentiated whenever neonates are reexposed to contingent presentations of the elements that defined the original associative memory.

Administration, Inhalation↗

Behavioral detection of low concentrations of ethanol in milk in the preweanling rat.

Previous animal models testing infantile reactivity to ethanol (EtOH) in maternal milk used EtOH doses that vastly exceeded levels actually encountered in a mildly or moderately intoxicated dam. The present study assessed whether 12- and 16-day-old rats are capable of detecting EtOH in milk at levels actually recorded in an intoxicated dam. Experiment 1 determined representative levels of EtOH in maternal milk as a function of maternal intragastric administration of EtOH (0.5-3.0 g/kg). Experiment 2A assessed generalization of conditioned taste aversions accrued with a high level of EtOH (6%) in either water or milk vehicles towards lower, more representative EtOH levels obtained from Experiment 1. With body weight gain as the dependent measure, conditioned aversions to milk were evident with the milk vehicle, but there was no detection of EtOH at any level at either age. Detection of the high level of EtOH (6%) in milk, however, was observed by 16 day olds within an habituation paradigm (Exp. 2b) via cardiac and behavioral (locomotion, mouthing) indexes. In Experiment 3 application of Experiment 2's more sensitive, behavioral index to assess generalization of the conditioned taste aversions revealed detection of a lower, more representative concentration of EtOH (175 mg%) in milk in 16-day-old rats. Overall the results show that the unweaned rat is capable of detecting very low concentrations of EtOH in milk and can modify their behavior accordingly. The expression of this capability is not, however, homogeneous across different response indexes. In conjunction with prior research it is clear that the infant rat's perception of EtOH in milk, including the very low levels of EtOH found in maternal milk during mild or moderate intoxication, is a relevant experience for generating new responses towards EtOH.

Animals↗

Neonatal responsiveness to alcohol odor and infant alcohol intake as a function of alcohol experience during late gestation.

It has been previously suggested that maternal alcohol intoxication during the last days of pregnancy promotes fetal experiences that include chemosensory processing of the drug. In this study pregnant Wistar-derived rats were administered saline or one of two alcohol doses (1 or 2 g/kg) during gestational days 17-20. Immediately after birth, pups were tested in regard to motor-eliciting properties of the odor of amniotic fluid or alcohol, or of these stimuli presented as a configuration. Saline controls showed significantly shorter duration of overall motor activity and head movements when stimulated with the biological cue (amniotic fluid) than when exposed to a novel stimulus (ethanol alone or configured with the amniotic fluid). The opposite pattern was found in pups with prenatal experience with the higher alcohol dose. In a second experiment, the impact of similar alcohol treatments on infant consumption of different tastants, including alcohol and a configuration of sucrose and quinine, was tested. This configuration appears to mimic psychophysical properties of ethanol. Consumption of water, sucrose, or quinine was unaffected by the prenatal status of the subjects. Antenatal alcohol experience with the lower alcohol dose (1 g/kg) increased both alcohol and sucrose-quinine consumption. The 2 g/kg alcohol animals also ingested more sucrose-quinine relative to saline controls. As a whole, the results confirm the hypothesis that an intrauterine alcohol sensory memory selectively affects neonatal recognition of the alcohol's olfactory attributes and infant intake of either alcohol or solutions that share certain sensory equivalence with this psychopharmacological agent.

Alcohol Drinking↗

Comparative study of the corrosion behavior of MA-956 and conventional metallic biomaterials.

In this work the corrosion behavior of a new biomaterial, the MA-956 superalloy, immersed in Hank's solution is evaluated. A comparison with conventional metallic alloys used as articular implants is established. To determine the corrosion behavior we employed electrochemical methods: evaluation of corrosion potential Ecorr, electrochemical impedance spectroscopy (EIS), and anodic polarization curves. The corrosion resistance of the MA-956 superalloy preoxidized at 1100 degrees C during 100 h is at least two orders of magnitude higher than for the other alloys. This satisfactory behavior is stationary with time. Also the probability of the appearance of the pitting corrosion process is very low. When cracking is generated in the alpha-alumina layer the repassivation process is assured because of the high Cr content in the superalloy. This study is the first step in proposing this new alloy as a biomaterial. The low toxicity of these metallic alloys in the physiological environment suggests that in vivo their biocompatibility could be satisfactory.

Alloys↗

MR imaging in inferior vena cava thrombosis.

PURPOSE: To prospectively evaluate the efficacy of MR imaging in inferior vena cava (IVC) thrombosis; to differentiate acute from non-acute thrombus, and to identify the presence of changes in the morphology and signal intensity during medical treatment. METHODS AND MATERIALS: Seventeen patients with suspected IVC thrombosis underwent 30 MR examinations. The IVC thromboses were subdivided into two groups (acute and non-acute) according to onset of clinical symptoms. MR imaging of the IVC was analyzed and when an IVC thrombus was identified, a qualitative and quantitative assessment of the thrombus on spin-echo sequences with magnitude and phase reconstruction was performed to evaluate the relationship between signal intensity and the time elapse since the onset of clinical symptoms. Venography and/or CT scan proof was available in all cases. RESULTS: IVC thrombus was correctly identified in 19 MR examinations which showed the size, localization and the degree of lysis during follow-up. No differences were found in the signal intensity of the thrombus related to time. The pattern of the signal intensity was homogeneous in six (86%) acute thrombus and heterogeneous in nine (75%) thrombus of more than 1 week duration. A significant statistical relationship (P < 0.01) existed between the thrombus age and differences in the pattern of signal intensity. CONCLUSIONS: MR imaging is accurate to assess the localization and size of IVC thrombus, similar to the imaging techniques of reference. In addition, MR also provides useful information about the age and the morphological variations of thrombus during medical treatment.

Acute Disease↗

Infant rats respond differently to alcohol after nursing from an alcohol-intoxicated dam.

Our previous studies indicate that rat pups are able to detect the low levels of ethanol (175 mg %) found in the milk of a moderately intoxicated dam. The present study tested the effect of infantile interactions (including suckling) with ethanol-treated mothers on later behavioral responsiveness to ethanol's sensory properties. In Experiment 1, pups suckled from dams subjected to a 2.5 g/kg ethanol dose (i.g.) or water-treated females during postnatal days (PDs) 3, 5, 7, 9, 11, and 13. During PD 15, these pups were exposed to procedures to induce a conditioned aversion to the low level of ethanol (175 mg % in water), with lithium chloride as the unconditioned stimulus. Conditioning was more effective for pups with the prior ethanol experience within the nursing context. Greater responsiveness to ethanol in milk also was found for conditioning control pups that had interacted with intoxicated dams than for those that had interacted with water-treated dams. Experiment 2 determined that interaction with an intoxicated dam was sufficient for altered responsiveness to ethanol, in that the additional conditioning procedures of Experiment 1 were not needed for the effect. Generally, a relatively brief history of infantile interaction with ethanol-intoxicated dams increased later responsiveness to ethanol's orosensory properties. The results suggest that moderately intoxicated dams within the nursing context provide information to the progeny that may lead to the establishment of ethanol-related memories.

Alcoholic Intoxication↗