Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The properties of periodontal mechanoreceptors innervating the lower canine teeth of cats have been determined 6 weeks and 1 year after sectioning the inferior alveolar nerve. Recordings were made from single fibres dissected from the nerve central to the injury site, whilst forces were applied at right angles to the long axis of the tooth. 2. The range of directions over which each mechanosensitive unit responded (are of sensitivity) was established. Forces were then applied in the direction of maximum sensitivity and the maximum discharge frequency, dynamic index, adaptation rate, and the force threshold at three rates of force application (0.25, 2 and 20 N s-1) were determined. 3. Data from 115 units characterized 6 weeks after nerve section revealed a significantly reduced mean dynamic index and raised mean force threshold to forces applied at 2 and 0.25 N s-1, when compared with the controls. These units were, however, more sensitive than those examined 12 weeks after nerve section in a previous study (Loescher & Robinson, 1989b). 4. Data from 158 units characterized 1 year after nerve section revealed a significantly narrower mean are of sensitivity, reduced mean maximum discharge frequency, lower mean dynamic index and raised mean threshold to forces applied at 0.25 N s-1, when compared with the controls. 5. Bone overlying the roots of the reinnervated teeth was removed in order to localize receptors in the underlying periodontal ligament. Forty-six units were localized 6 weeks after nerve section and thirty-eight 1 year after nerve section. The mean conduction velocity of these units was significantly reduced both 6 weeks and 1 year after nerve section compared to the controls. One unit was found which branched to innervate receptors at two locations within the ligament, and one unit was found which branched to innervate a receptor in the ligament and another in the overlying skin. 6. The higher level of sensitivity of receptors when first reinnervated than at later stages is attributed to their immaturity. This immaturity may also contribute to the paraesthesia which is experienced by patients at a corresponding stage in recovery from nerve injury. The persistent reduction in sensitivity of units 1 year after nerve injury suggests that changes occur which have a permanent effect on their properties.
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PMID:Properties of periodontal mechanoreceptors supplying the cat's lower canine at short and long periods after reinnervation. 182 67

After having been virtually completely forgotten since the Second World War, paediatric regional anaesthesia has been undergoing a renewal in the last decade. This renewed interest in old techniques is due to several converging factors: a better knowledge of the pharmacology of local anaesthetic agents in the child, the availability of equipment adapted for children, the remarkable haemodynamic stability of the very young child during an epidural block, as well as the need to treat pain not just in the operative period. The child is not, or rather, is not only a small adult. Embryological development is not finished at birth. The incompletely myelinized nervous system as well as the incomplete skeletal ossification will influence local anaesthetic pharmacodynamics and the choice of anaesthetic technique and anatomical landmarks. Aponeurotic sheaths are only poorly attached to anatomical structures, especially nerves. This, together with the fact that epidural fat in the young child is very fluid, explains why some techniques are very efficient, but also why the volumes of required anaesthetic solution are proportionately much more important than in adults. The general pharmacology of local anaesthetic drugs is very close to adults. However, the very important regional blood flow rates, the different body water distribution, the immature neurovegetative system, the weak activity of some enzymes, and the relatively greater importance of the liver and brain by weight explain the differences found in pharmacokinetics, which are differences in degree and not in nature. The choice of the appropriate local anaesthetic agent depends on these factors. In France, the chosen drug will almost exclusively be an amide, mostly lignocaine and bupivacaine. The psychological immaturity of children makes any assessment of pain quite difficult. Moreover, body image has not yet been completely acquired in most cases, so reducing the possibility of conceptualization. The usefulness of techniques requiring an active patient participation, in particular the search for paraesthesia, is therefore rather reduced. Light general anaesthesia and peripheral nerve stimulators (for nerve blocks) are essential, and desirable at least, if not wished by most patients. Caudal anaesthesia is an important technique in the child. It is easy to perform, efficient, with small risk. Its ideal indication is surgery below the umbilicus in the infant and young child. Lumbar epidural anaesthesia requires greater experience as well as proper equipment, especially in the very young child. Peripheral nerve blocks are less used than in adults.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Regional anesthesia in pediatrics]. 265 20

The most critical phase of exposure to schistosomal infection is the infancy, because of the more frequent contact with contaminated water and the immaturity of the immune system. One of the most severe presentations of this parasitosis is the involvement of the spinal cord, which prognosis is largely dependent on early diagnosis and treatment. Reports on this clinical form of schistosomiasis in children are rare in the literature. We present here the clinical-epidemiological profile of schistosomal myeloradiculopathy (SMR) from ten children who were admitted at the Instituto Materno-Infantil de Pernambuco over a five-year period. They were evaluated according to an investigation protocol. Most of these patients presented an acute neurological picture which included as the main clinical manifestations: sphincteral disorders, low back and lower limbs pain, paresthesia, lower limbs muscle weakness and absence of deep tendon reflex, and impairment of the gait. The diagnosis was presumptive in the majority of the cases. This study emphasizes the importance of considering the diagnosis of SMR in pediatric patients coming from endemic areas who present a low cord syndrome, in order to start the appropriate therapy and avoid future complications.
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PMID:Clinical-epidemiological profile of children with schistosomal myeloradiculopathy attended at the Instituto Materno-Infantil de Pernambuco. 1730 63