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Biomedical subjects

D Martin

Publications and source records attributed to D Martin.

At least 217 records · Page 12Linked to original sources
PubMed2000

[The scapula: a preferred donor site for a free flaps or pedicles transfer].

The authors present all the possibilities that the scapula can offer as a donor site for bone. After having reviewed the potential for acromial transfer on a pedicled trapezial flap, they summarise the anatomical basis for the transfer of the lateral border. There are two systems of vascular supply, one based on the circumflex scapular vessels described by Téot and the other based on the vessels of the angle of the scapula described by Deraemacker. This dual blood supply forms a very rich anastomosis with a predominant periosteal supply that allows for multiple osteotomies to be made. The technique of harvesting and the indications are highlighted as well as an iconography, which presents the principle forms of reconstruction that have been described until today. The authors support the use of the pedicled transfer of the lateral border, which is poorly known and above all poorly used. Their experience in five consecutive clinical cases demonstrates all the potential of this technique for humeral reconstruction. As a microsurgical transfer, however, the principal advantage of using the inferior scapular axis is offset by a few drawbacks, the principal one being the difficulty of dissection. Its main indication as a free flap is in the maxillofacial surgery where it allows very precise reconstructions of the mandible, the palate or the maxillozygomatic region.

Bone Transplantation↗
PubMed2000

[The technique and location of secondary donor sites of vascularized bone grafts in the therapeutic arsenal of the plastic surgeon].

Most of the donor sites for conventional bone grafts can also provide vascularised bone grafts. Increased progress in vascular research has enabled the harvesting of grafts that are increasingly reliable and versatile. This work does not give emphasis to classic vascularised bone transfers like the iliac crest, the fibula or the lateral border of the scapula but highlights 'secondary' sites which are often underutilized. Several donor areas are studied; the upper limb including the clavicle, the lower limb, the thorax and the cranium. The hands and toes, which constitute a specific entity, are excluded. In each chapter the authors have emphasised the fundamental points relating to the anatomy, the technique of harvesting and the indications.

Bone Transplantation↗
PubMed2000

[Contribution of magnetic resonance imaging in sclerotic combined degeneration of the spinal cord due to vitamin B12 deficiency].

Subacute combined degeneration (SCD) of the spinal cord is known to present histopathologically degenerative lesions in the spinal cord, but few studies on the neuroradiological findings have so far been reported. We present the interest of initial and follow-up MR findings in three cases of SCD. In the three cases, a causal event precipitated the onset of neurological symptoms: general anesthesia for the first and the third one and folic acid treatment for the second one. Clinical evolution was favorable after specific treatment with nearly total recovery. The initial MR study disclosed lesions predominantly involving the posterior columns of the spinal cord: high intensity on T2 weighted image was seen in the initial MR study and disappeared three months after treatment in correlation with good recovery, but with a delay. The recognition of this MR pattern suggests that MRI may be used in conjunction with clinical assessment to confirm the diagnosis and to monitor the efficacity of treatment in SCD.

Aged↗
PubMed2000

A maize chromosome 3 addition line of oat exhibits expression of the maize homeobox gene liguleless3 and alteration of cell fates.

Maize chromosome addition lines of oat offer the opportunity to study maize gene expression in oat and the resulting phenotypes. Morphological examination of a maize chromosome 3 addition line of oat showed that this line exhibited several morphological abnormalities including a blade-to-sheath transformation at the midrib region of the leaf, a hook-shaped panicle, and abnormal outgrowth of aerial axillary buds. Dominant mutations in the maize liguleless3 (lg3) homeobox gene result in a blade (distal)-to-sheath (proximal) transformation at the midrib region of the leaf. Ectopic expression of the dominant mutant Lg3 allele is believed to cause the phenotype. Therefore, we suspected that the maize lg3 gene, which is located on maize chromosome 3, was involved in the phenotypes observed in the maize chromosome 3 addition line of oat. Genetic analyses of an oat BC1F2 family segregating for maize chromosome 3 showed that the presence of a stable maize chromosome 3 was required for the expression of these cell fate abnormalities. RNA expression analysis of leaf sheath tissue from oat plants carrying maize chromosome 3 demonstrated that maize LG3 transcripts accumulated in oat, indicating that this expression is associated with the blade-to-sheath transformation, hook-shaped panicle and outgrowth of aerial axillary bud phenotypes. Our results demonstrate that the maize chromosome addition lines of oat are useful genetic stocks to study expression of maize genes in oat.

Avena↗
PubMed2000

Understanding dysfunctional and functional family behaviors for the at-risk adolescent.

At-risk adolescents and their impact on families and society, as well as characteristics of both healthy and maladaptive families, are discussed. Cognitive distortions of dysfunctional adolescents and their effect on family members, along with methods for intervention and creating more healthy environments, are delineated from a systemic viewpoint.

Adult↗
PubMed1999

Teneurins: a novel family of neuronal cell surface proteins in vertebrates, homologous to the Drosophila pair-rule gene product Ten-m.

We have characterized chicken teneurin-1 and teneurin-2, two homologues of the Drosophila pair-rule gene product Ten-m and Drosophila Ten-a. The high degree of conservation between the vertebrate and invertebrate proteins suggests that these belong to a novel family. We propose to name the vertebrate members of this family teneurins, because of their predominant expression in the nervous system. The expression of teneurin-1 and -2 was investigated by in situ hybridization. We show that teneurin-1 and -2 are expressed by distinct populations of neurons during the time of axonal growth. The most prominent site of expression of chicken teneurins is the developing visual system. Recombinant teneurin-2 was expressed to assay its molecular and functional properties. We show that it is a type II transmembrane protein, which can be released from the cell surface by proteolytic cleavage at a furin site. The expression of teneurin-2 in neuronal cells led to a significant increase in the number of filopodia and to the formation of enlarged growth cones. The expression pattern of teneurins in the developing nervous system and the ability of teneurin-2 to reorganize the cellular morphology indicate that these proteins may have an important function in the formation of neuronal connections.

Amino Acid Sequence↗
PubMed1999

Arrhythmias and conduction defects as presenting symptoms of fatty acid oxidation disorders in children.

BACKGROUND: The clinical manifestations of inherited disorders of fatty acid oxidation vary according to the enzymatic defect. They may present as isolated cardiomyopathy, sudden death, progressive skeletal myopathy, or hepatic failure. Arrhythmia is an unusual presenting symptom of fatty acid oxidation deficiencies. METHODS AND RESULTS: Over a period of 25 years, 107 patients were diagnosed with an inherited fatty acid oxidation disorder. Arrhythmia was the predominant presenting symptom in 24 cases. These 24 cases included 15 ventricular tachycardias, 4 atrial tachycardias, 4 sinus node dysfunctions with episodes of atrial tachycardia, 6 atrioventricular blocks, and 4 left bundle-branch blocks in newborn infants. Conduction disorders and atrial tachycardias were observed in patients with defects of long-chain fatty acid transport across the inner mitochondrial membrane (carnitine palmitoyl transferase type II deficiency and carnitine acylcarnitine translocase deficiency) and in patients with trifunctional protein deficiency. Ventricular tachycardias were observed in patients with any type of fatty acid oxidation deficiency. Arrhythmias were absent in patients with primary carnitine carrier, carnitine palmitoyl transferase I, and medium chain acyl coenzyme A dehydrogenase deficiencies. CONCLUSIONS: The accumulation of arrhythmogenic intermediary metabolites of fatty acids, such as long-chain acylcarnitines, may be responsible for arrhythmias. Inborn errors of fatty acid oxidation should be considered in unexplained sudden death or near-miss in infants and in infants with conduction defects or ventricular tachycardia. Diagnosis can be easily ascertained by an acylcarnitine profile from blood spots on filter paper.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1999

[Dr. Quiz: a program of medical question-data bank with access to Internet].

The authors' aim was to develop a programme of medical question-databank which could be used for self-assessment of knowledge. The programme incorporates computer-network technology utilising the Internet. The duration of Internet connection of users is merely limited to the time of selecting and downloading a group of questions. The series of multiple choice questions follows the decision making process of physicians from the description of the medical case to establishing the diagnosis and the therapy. The series of questions can be branched depending on the level of knowledge and the answers are evaluated with different number of scores emphasising the medical significance of the concrete question. Detailed explanations are attached to all possible responses and the general summary of the case can be read after completing the task. The addresses of the authors creating the different cases are also saved and in this way there is a chance of the direct communication between the authors and the users. Special feature of the programme is that when the users want to download a new group of questions, their previous answers are fed back to the server in order to get the possibility of improving the quality of the question-databank by means of an appropriate statistical analysis. At present, the programme is at the stage of checking and complementing.

Databases, Factual↗
PubMed1999

Nurses at the gate.

Explore the source record for details and available documents.

Emigration and Immigration↗
PubMed1999

Grafts of meningeal fibroblasts in adult rat spinal cord lesion promote axonal regrowth.

We have studied the morphological consequences of implantation into the injured adult rat spinal cord of fibroblasts derived from the meninges overlying the cerebral cortex. Our initial objective was to reproduce the well known post-traumatic fibroadhesive scar observed in the clinical situation. One month after implantation, instead of having formed a fibroadhesive scar, fibroblasts had promoted the regeneration of peptidergic axons originating from dorsal root afferents and, to a lesser extent, of supraspinal serotonergic fibers at the periphery of the grafts. Using RT-PCR we were able to identify in cultures of meningeal-derived fibroblasts mRNAs for beta-NGF, NT3, aFGF and bFGF, which suggests that the promoting effect on axonal regeneration of these cells is at least in part due to their capacity to synthesize neurotrophic factors.

Animals↗
PubMed1999

Meningococcal disease in Auckland, July 1992 - June 1994.

AIMS: To assess two years of meningococcal disease in the Auckland area, the outcomes and management issues, and the specific socio-geographic groups that are affected. METHODS: Using the nationally agreed case definition, a retrospective chart review was undertaken. Case finding was through the National surveillance system at ESR, backed by hospital laboratory and coroner case findings. RESULTS: There were 106 cases of meningococcal disease, both adult and paediatric, from July 1992 to June 1994. Group B (n=61), was predominant throughout this period especially in the winter months. There were two main age groups most affected. The first, and most striking, was in Maori and New Zealand Pacific Island children younger than five years, with rates of 52.6 and 54.2/100,000 respectively. The second peak was in European, and to a lesser extent Maori, 15-24 year-olds, (rates 11.7 and 8.5/100,000, respectively). The annual incidence was 5.6/100,000 with an overall case fatality rate of 6.6%, (n=7). South Auckland had the greatest proportion of cases with 42/106. Two-thirds of the cases were referred for hospital admission by a general practitioner. From both general practitioner and self-referred groups, two-thirds had a petechial/purpuric rash on arrival at hospital. For general practitioner referred cases, 24 received parenteral antibiotics on referral, and from these cases there was one death, (1/24). Those not treated with antibiotics (general practitioner or self-referred) had a mortality of 2/41. There were 31 cases of paediatric meningococcal meningitis. Nineteen cases had dexamethasone in appropriate dose and timing; no hearing loss occurred in the 17 cases that survived (0/17), compared to 2/12 not treated with dexamethasone. This compares to a published rate of 5-7%. CONCLUSIONS: Meningococcal disease, predominantly serogroup B, is of high incidence in Auckland. The highest rates of disease are occurring in the under five-year-olds, where an effective group B vaccine is awaited. The benefit of dexamethasone is suggestive. There was no clear benefit in outcome by pre-treatment with parenteral antibiotics for paediatric meningococcal disease though no suggestive detrimental effect either.

Adolescent↗
PubMed1999

wing blister, a new Drosophila laminin alpha chain required for cell adhesion and migration during embryonic and imaginal development.

We report the molecular and functional characterization of a new alpha chain of laminin in Drosophila. The new laminin chain appears to be the Drosophila counterpart of both vertebrate alpha2 (also called merosin) and alpha1 chains, with a slightly higher degree of homology to alpha2, suggesting that this chain is an ancestral version of both alpha1 and alpha2 chains. During embryogenesis, the protein is associated with basement membranes of the digestive system and muscle attachment sites, and during larval stage it is found in a specific pattern in wing and eye discs. The gene is assigned to a locus called wing blister (wb), which is essential for embryonic viability. Embryonic phenotypes include twisted germbands and fewer pericardial cells, resulting in gaps in the presumptive heart and tracheal trunks, and myotubes detached from their target muscle attachment sites. Most phenotypes are in common with those observed in Drosophila laminin alpha3, 5 mutant embryos and many are in common with those observed in integrin mutations. Adult phenotypes show blisters in the wings in viable allelic combinations, similar to phenotypes observed in integrin genes. Mutation analysis in the eye demonstrates a function in rhabdomere organization. In summary, this new laminin alpha chain is essential for embryonic viability and is involved in processes requiring cell migration and cell adhesion.

Alleles↗
PubMed1999

Specificity of assays used by regulatory agencies to detect antibiotic residues in tissues of culled dairy cows.

OBJECTIVE: To determine percentage of false-positive test results for assays used by regulatory agencies to detect antibiotic residues in tissues. DESIGN: Prospective study. ANIMALS: 426 dairy cows. PROCEDURE: Dairy cows scheduled for culling that were identified as being unlikely to have antibiotic residues in tissues on the basis of strict inclusion criteria were used. A sample of kidney obtained from each cow at slaughter was tested on-site, using the swab test on premises (STOP; 97 samples) or the fast antibiotic screening test (FAST; 329 samples). Frozen samples (n = 1,278) of liver, muscle, and kidney were thawed and retested at a federal laboratory, using the same screening assays. Kidney and liver samples (n = 852) were also tested using the 7-plate bioassay confirmation test used for confirmation and identification of antibiotic residues. RESULTS: Results of screening assays performed onsite were negative. When frozen samples were retested, 20 (12 liver, 7 kidney, and 1 muscle) had positive FAST results, but none had positive STOP results. Of the samples tested with the 7-plate bioassay confirmation test, 4 liver samples had results indicating a tetracycline (n = 3) or an unidentified microbial inhibitor (1) as a residue. CLINICAL IMPLICATIONS: Results suggest it is unlikely that regulatory action will be taken against producers sending untreated cattle to market. However, because results of the FAST and 7-plate bioassay confirmation test were positive when applied to frozen tissue, use of assays based on microbial inhibition may not be valid for confirmation of residues.

Animals↗
PubMed1999

Impact of the application of neurolinguistic programming to mothers of children enrolled in a day care center of a shantytown.

CONTEXT: Of the members of a family, the mother is without doubt the most important one, which provides justification for including an evaluation of her mental health as one of the variables to be considered as determining factors in each child's level of development. OBJECTIVE: To assess the impact of the application of Neurolinguistic Programming (NLP) on child development, home environment and maternal mental health. DESIGN: Randomised controlled trial. SETTING: The study included children enrolled in the municipal day care center of a shantytown in the City of São Paulo. PARTICIPANTS: 45 pairs of mothers and respective children between 18 and 36 months of age. MAIN MEASUREMENTS: Children's development (Bayley scales); home environment variation (HOME); and maternal mental health (SRQ). Comparison between before and after the intervention was made in terms of children's psychomotor development, home environment and maternal mental health. INTERVENTION: Application of the NLP technique to the experimental group and comparison with a control group. 1--Experimental (EG), consisting of 23 children submitted to intervention by NLP; and 2--Control (CG), with 22 children with no intervention. Length of intervention: 15 sessions of NLP. RESULTS: 37 children remained in the study (EG = 10, CG = 27). Variations in mental development (OR 1.21, IC 95% 0.0 to 23.08) in their home environment (Wilcoxon): p = 0.96 (before) and p = 0.09 (after); in maternal mental health: p = 0.26, 2 df. CONCLUSIONS: There was a trend that indicated positive effects on the home environment from the intervention.

Child Day Care Centers↗
PubMed1999

Transport of phospholipid synthesis precursors and lipid trafficking into malaria-infected erythrocytes.

Phospholipid biosynthesis in Plasmodium is of crucial importance considering the high degree of membrane biogenesis. In the de novo phosphatidylcholine pathway, the major plasmodial phospholipid, choline, first enters infected erythrocytes by a transport-mediated process, whose main kinetic characteristics are the same as in normal cells except for a considerable increase in Vm. The kinetic and functional characterizations of the choline carrier (affinity, specificity, stereoselectivity, asymmetric cyclic model, ionic dependence, limiting step in carrier translocation) have now been done, although there is no information concerning its nature and structure, despite the fact that it is likely an outstanding pharmacological target. Other unanswered questions concern the mechanisms for choline entry into the parasite. The intense lipid trafficking between the intracellular parasite and the host cell membrane also indicates that Plasmodium controls its own lipid composition as well as that of its host cell. Organelles that house the machinery for lipid synthesis, and mechanisms for trafficking and sorting, have not yet been described because of the lack of appropriate tools, but they could address fundamental questions in the contemporary cell biology of this parasite.

Animals↗