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Biomedical subjects

L Jodar

Publications and source records attributed to L Jodar.

8 recordsLinked to original sources
PubMed2001

Ensuring vaccine safety in immunization programmes--a WHO perspective.

Ever since vaccines were firstly used against smallpox, adverse events following immunization have been reported. As immunization programmes expand to reach even the most remote communities in the poorest countries, it is likely that many more events will be temporally linked with vaccine administration. Furthermore, the profound shift in the general public and media interest in adverse events may lead to undue concerns and allegations which may ultimately jeopardize immunization programmes world-wide. While the health professional has understood this issue for some time, the public and the media have now also become all too aware of the significance of vaccine-related adverse events. The familiar vaccines, well-tested over decades, have not changed--but the perception regarding their safety has shifted. Claims outrageous or reasonable are being made against both the old and the newly-introduced vaccines. At the same time, the immunological and genetic revolution of the last decade may well bring to our notice some hypothetical risks that need to be addressed at pre-clinical level. WHO has been at the leading edge to guarantee vaccine safety for the last 30 years and will continue to do so. The Organization's plans for the next decade and beyond include the Safe Injection Global Network (SIGN), the development and introduction of safer technologies, and the prevention, early detection and management of AEFIs. The new technologies include needle-containing injection devices such as the autodisable syringe, as well as mucosal and transcutaneous immunization. Training will continue to be at the centre of WHO's efforts, limiting human error to a minimum. Mechanisms have been set in place to detect and respond to new and unforeseen events occurring. Above all, there is a willingness to respond to new climates and new technologies so that the Organization is in the best position to ensure safe immunization for all the world's children.

Drug Contamination↗
PubMed1996

FS stress induces long-lasting memory facilitation: involvement of cholinergic pathways.

We tested in vivo the hypothesis that foot-shock (FS) stress-induced prolongation of latencies in the one-trial step-through passive avoidance learning task in mice occurred through a long-term facilitation process. Whereas behavioral responses in control mice lasted for 24 h, decreasing progressively in the subsequent days, FS-stress exposure for 15 min before training (pretraining), immediately after training (posttraining), or 15 min before the test (pretest) resulted in a profound and sustained enhancement of test latencies that lasted for at least 96 h. These facilitating effects disappeared when FS exposure was delivered with a 2- or 3-h difference with respect to the training trial. Scopolamine (Scop) (1 mg/kg, intraperitoneally) 30 min before the training session caused impairment of test latencies in control and pretest stressed animals, but failed to affect both pre- and posttraining FS stress-induced enhancement. Our working hypothesis is that FS stress may increase the levels of acetylcholine in the presynaptic terminal or the firing rate of cholinergic input. Animals pretreated with FS stress daily for 1 or 4 days followed by the acute schedule described above showed no enhancements of test latencies. Pretraining Scop impaired test latencies in pre- and posttraining and pretest stressed animals, suggesting that unpredictability is a critical factor in activating behavioral long-term facilitation.

Animals↗
PubMed1995

Inheritance of histiocytosis in Bernese mountain dogs.

One hundred and twenty-seven cases of histiocytosis in Bernese mountain dogs (BMD) were evaluated to determine if the tumour is inherited. Family data ruled out autosomal recessive, autosomal dominant and sex-linked modes of inheritance. The trait was determined to be inherited with a polygenic mode of inheritance. The salient points permitting this conclusion are: pedigrees developed from independently selected propositi link up allowing the tracing of all cases through several generations; multiple cases occur in the same litter; multiple cases have been produced by given dams and sires; there is a higher frequency of the disease among offspring of affected parents when compared to offspring of normal parents that produced histiocytosis and all offspring in the general population of BMDs; the fact that histiocytosis is common in BMDs and rare in eight other breeds and accounts for 25.4 per cent of the 500 tumours studied in this breed. The heritability of this trait was calculated to be 0.298.

Animals↗
PubMed1995

Effects of footshock-, psychological- and forced swimming-stress on the learning and memory processes: involvement of opioidergic pathways.

Modulation of learning and memory acquisition, retention and retrieval in the one trial passive avoidance learning task in mice by three inescapable stresses, i.e., footshock (FS), psychological (PSY) and forced swimming (SW) were investigated. Pre-, post-training and pre-test FS-stress (2 mA, 0.2 Hz, 1 sec for 30 min) and pre-training PSY-stress (communication box, 5 min) resulted in enhanced test latencies. On the contrary, SW-stress (20 degrees C, 5 min) immediately or 1 hr after training impaired retention latencies that tended to recover after 2 hr post-training SW-stress, suggesting that at least 2 hr are required to consolidate newly acquired information. In contrast, pre-stress naloxone (Nx), which did not affect FS- and PSY-stress induced facilitatory effects, returned to control levels the impaired retention latencies induced by SW-stress. Taken collectively, these results imply the involvement of an opioid-dependent mechanism in the modulation of memory by SW-stress and non-opioid in the case of FS- and PSY-stress. Furthermore, they suggest that different mechanisms are involved in stress-induced memory modifications and the production of stress-induced analgesia (SIA) since in the latter, FS and PSY but not SW stress produce Nx-sensitive antinociception.

Animals↗
PubMed1995

Synaptic plasticity: stairway to memory.

Since the idea that memory is associated with alterations in synaptic strength was accepted, studies on the cellular and molecular mechanisms responsible for the plastic changes in neurons have attracted wide interest in the scientific community. Recent studies on memory processes have also pointed out some unifying themes emerging from a wide range of nervous systems, suggesting that regardless of the species or brain regions, a common denominator for memory may exist. Thus, the present review attempted to create a hypothetical and universal synaptic model valid for a variety of nervous systems, ranging from molluscs to mammals. The cellular and molecular events leading to short- and long-term modifications of memory have been described in a sequential order, from the triggering signals to the gene expression, synthesis of new proteins and neuronal growth. These events are thought to represent the late phases of memory consolidation leading to persistent modifications in synaptic plasticity, thereby facilitating the permanent storage of acquired information throughout the individual's life.

Animals↗
PubMed1994

Trends in physiological role of opioids in psychoneuroendocrine-immune network.

Extensive evidence suggests that opioid influences on the immune response are mediated through opioid receptors on the surface of immune cells. In addition, the binding of opioid agonists to centrally located opioid receptors appears also to alter immune activity through interactions with the neuroendocrine and the nervous systems. Finally, other findings summarized in this review provide evidence consistent with the hypothesis that under stressful stimuli, the immune system is altered through the interrelations among the neuroendocrine system, the sympathetic nervous system and central opioidergic pathways.

Animals↗