Clopidogrel and aplastic anaemia.
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Aged↗
Biomedical subjects
B Meyer
Publications and source records attributed to B Meyer.
Sutureless mechanical anastomosis of a saphenous vein graft to a coronary artery with a new connector device.
Construction of vascular anastomoses by manual suturing is a highly skilled and time-consuming procedure. The St Jude Medical Anastomotic Technology Group has developed a sutureless mechanical anastomosis device, which, when tested in animals, produced anastomoses in less than 3 min and with little training. Here we present the results of the first clinical saphenous-vein to coronary-artery anastomosis by means of this device.
Coronary Artery Bypass↗
Influence of transcranial magnetic stimulation on pupil size.
In 22 healthy subjects, painless repetitive transcranial magnetic stimulation (rTMS) was used to investigate the role of the cortex in the regulation of pupil size and the influence of TMS on the central autonomic nervous system. RTMS was performed over three brain regions of each hemisphere (frontal, central, parieto-occipital), over cervical nerve roots and in front of the ear (sham stimulation) while the size of the pupil was measured by infrared oculography. rTMS always elicited a dilatation of both pupils, with its maximum after approximately 1.5 s and without significant R-L difference in latency or amplitude of pupillary response. No differential effects were observed for stimulation over different cortex regions of one hemisphere, but stimulation over the right central region evoked a larger dilatation of the pupil than stimulation over the left. Pupillary dilatation was larger for cervical nerve root stimulation (+13.2+/-8.3% (S.D.) of baseline) than for suprathreshold cortex stimulation (+8.4+/-4.5%, five 10-Hz stimuli). Pupillary dilatation in response to magnetic cortex stimulation appears to reflect a mainly unspecific activation of the sympathetic system rather than an activation of a cortical pupillomotor centre. Sympathetic activation following rTMS of the cortex does not limit its experimental and therapeutic application.
Adult↗
Characterization of a mutation in the lens-specific MP70 encoding gene of the mouse leading to a dominant cataract.
During an ethylnitrosourea mutagenesis screen, Aey5, a new mouse mutation exhibiting an autosomal dominant congenital cataract was isolated. The cataractous phenotype is visible at the eye opening and progresses to a nuclear and zonular cataract at 2 months of age with no difference in onset or severity between heterozygous and homozygous mutants. Histological analysis revealed that fiber cell differentiation continues at the lens bow region, but the cell nuclei do not degrade normally and remain in the deeper cortex. Further, the lens nucleus has clefts of various sizes while the remainder of the eye was morphologically normal. The mutation was mapped to chromosome 3 between the markers D3Mit101 and D3Mit77 near the connexin encoding genes Gja5 and Gja8. Sequence analysis revealed no differences in the Gja5 gene, but identified a T-->C mutation at position 191 in the Gja8 gene, which was confirmed by an additional Mva 12691 restriction site in the genomic DNA of homozygous mutants. This mutation results in Val-->Ala substitution at codon 64 of connexin50 (Cx50) also known as lens membrane protein 70 (MP70). Aey5 represents the second dominant mouse cataract mutant affecting Cx50, a membrane protein preferentially expressed in the lens. Since both mutations affect similar regions in the first extracellular domain this region appears to be critically important for its function in lens transparency.
Animals↗
Characterization of intracellular bacteria in the freshwater dinoflagellate Peridinium cinctum.
Intracellular bacteria belonging to two phylogenetically different groups of eubacteria were found in cultures of the freshwater dinoflagellate Peridinium cinctum (O.F. Müller) Ehrenberg isolated from the eutrophic lake Plusssee (Federal Republic of Germany). The phylogenetic relationships of the bacteria were studied with fluorochrome-conjugated oligonucleotides specific for archaebacteria, eubacteria, alpha-, beta- and gamma-proteobacteria, complementary to 16S rRNA and 23S rRNA sequences, respectively. The bacteria are members of the eubacterial alpha- and gamma-subgroups of proteobacteria.
Animals↗
Surgery for upper cervical spine instabilities in children.
BACKGROUND: Due to the paucity of existing data with regard to surgical fusion of upper cervical spine instabilities in the paediatric population, we feel encouraged to report the results of our own series to provide additional information to the available body of literature. METHODS: Since 1991 N = 11 children underwent a total of N = 13 surgical procedures for N = 8 posttraumatic, N = 2 congenital and N = 1 postinfectious instabilities at a mean age of 10 years (range: 3-16 years). Transoral odontectomies, ventral odontoid screw-fixations, dorsal wiring or -clamping and transarticular screw-fixations were performed for stabilization and iliac crest bone graft used for fusion. Pain scores, neurological status and radiological results were documented at regular intervals (mean follow-up: 25.4 months). RESULTS: Stable fusion was achieved in all patients as documented on flexion/extension films and tomographies. At the latest follow-up N = 2 patients had improved and N = 9 were equal to their preoperative neurological status. Pain scores were improved in N = 9 patients. N = 2 children developed "bystander-fusion" after C0/2 wiring. N = 3 peri-operative complications occurred as transient neurological deteriorations. In one case this resulted from the resection of a lower brainstem tumour prior to the stabilization procedure. One was attributed to sublaminar wiring in the case of an os odontoideum and one occurred due to slippage of the halo orthosis after transoral odontectomy before definitive dorsal stabilization was carried out. INTERPRETATION: In accordance with the recent literature, we argue for the application of modern screw fixations and treatment algorithms as established for adults in upper cervical spine instabilities of older children. Techniques and indications remain problematic for those younger than 6 years and may have to be individualized in congenital instabilities.
Adolescent↗
Tumour surgery of the upper cervical spine--a retrospective study of 13 cases.
A series of tumour cases of the upper cervical spine who we had treated was analysed retrospectively with respect to surgical complications, quality of life and survival, 13 patients (mean age 56 years, metastases 6, plasmocytomas 3, chordomas 2, histiocytosis 1, aneurysmal bone cyst 1) with tumours of the upper cervical spine (C2 n = 7, C2 and C3 n = 4, C3 n = 2) were treated during an 8-year period. A total of 16 operations were carried out with ten one-step procedures and three two step-procedures. Eight extra-oral, one transoral, three dorsal and, in one case, a combined dorsal and extra-oral tumour removal were performed. Four dorsal stabilisation's, four ventral platings and two combined ventral platings plus dorsal fixations and eight vertebral body replacements were carried out. The neurological status and the quality of life were analysed preoperatively and during the follow-up examinations. Flexionextension radiographs were taken during follow-up. There was no operative mortality. The transient morbidity was 8%. The operative intervention significantly improved the quality of life in all patients during the follow-up visits (mean: 20 months). No instability was seen. The average survival time of all patients was 23 months. Six patients died following the operation after a mean time of 28 (4-64) months. Tumour removal in the upper cervical spine using individually modified surgical strategies based on an approach combining tumour location, stabilisation and vertebral body replacement significantly increases the time of survival and quality of life with an acceptable surgical risk for complications.
Adult↗
Left posterior BA37 is involved in object recognition: a TMS study.
Functional imaging studies have proposed a role for left BA37 in phonological retrieval, semantic processing, face processing and object recognition. The present study targeted the posterior aspect of BA37 to see whether a deficit, specific to one of the above types of processing could be induced. Four conditions were investigated: word and nonword reading, colour naming and picture naming. Repetitive transcranial magnetic stimulation (rTMS) was delivered over posterior BA37 of the left and right hemispheres (lBA37 and rBA37, respectively) and over the vertex. Subjects were significantly slower to name pictures when TMS was given over lBA37 compared to vertex or rBA37. rTMS over lBA37 had no significant effect on word reading, nonword reading or colour naming. The picture naming deficit is suggested to result from a disruption to object recognition processes. This study corroborates the finding from a recent imaging study, that the most posterior part of left hemispheric BA37 has a necessary role in object recognition.
Adult↗
Cochlear implant assessment: imaging issues.
Cochlear implants are electronic auditory prostheses used to rehabilitate deafened persons who have lost their hair cells. They are partly worn externally and partly implanted in the ear. They provide a direct stimulation of the spiral ganglion cells of the cochlear nerve by bypassing the destroyed hair cells. The objectives of this article are to summarise what head and neck surgeons need to know before cochlear implantation and to describe the imaging study protocol used and anomalies to look for. A few explanations are resumed about placement of a brainstem implant.
Brain↗
Maintaining prevention in practice: survival of PPIP in primary care settings. Put Prevention Into Practice.
INTRODUCTION: Put Prevention Into Practice (PPIP) consists of a kit of office-based tools intended to support the provision of preventive services by primary care providers. The purpose of this study was to examine the institutionalization of PPIP within five primary care clinics funded by the Texas Department of Health to implement PPIP, and to examine the organizational determinants of program institutionalization. METHODS: We utilized an adaptation of the Level of Institutionalizaton (LoIn) scales for qualitative data collection and for development of an institutionalization score for each site. The determinants of institutionalization were derived from the organizational behavior and health promotion literatures and used as categories for analysis. In addition, for purposes of triangulation, chart audit data for three documentation behaviors were also collected. RESULTS: PPIP has been maintained--at varying degrees of integration--in four of the five sites studied, for 6 years after adoption. Organizational factors that facilitated the institutionalization process were the site's institutional strength, the integration of PIPP within extant programs and services, visibility of the program within and outside the site, planning for the termination of grant funding, and presence of a program champion with mid- to upper-level managerial authority. Successful initiation of the program was not a predictor of institutionalization outcomes. CONCLUSIONS: We have highlighted the need to consider organizational determinants of institutionalization in relation to their specific sociopolitical contexts, and in relation to each other, not in isolation.
Health Plan Implementation↗
Violent behaviors in early adolescent minority youth: results from a "middle school youth risk behavior survey".
OBJECTIVES: To describe the prevalence and characteristics of violence and violence-related behaviors among six populations of U.S. minority adolescents in grades 6-8. METHODS: Six thousand four hundred non-White adolescents were recruited from six sites that were part of a collaborative project. Surveys were administered either during the school day or at community facilities. All students at each site were asked 10 questions about recent violence-related behaviors (including use of threats, fighting, weapon carrying, and weapon use). Prevalence of each violence-related behavior was reported within and across sites, and stratified by race/ethnicity, gender, age, and other characteristics expected to influence the behaviors. RESULTS: Sixty-six percent (66%) of the middle school students sampled reported being involved in some type of recent fighting and/or weapon-related behaviors. Sixty-one percent (61%) indicated some form of fighting behavior in the past 3 months (threatening to beat someone up, physical fighting, and/or being hurt in a fight). Thirty percent (30%) of participating youth reported one or more weapon-related behaviors (threatening to use a weapon, carrying a weapon, using a weapon, and/or being cut, stabbed or shot at). Reported gun carrying among males varied depending upon site, but was as high as 20%. Grade in school was positively associated with reported violent behaviors. Adolescents who reported living full-time with a parent or parent figure, and those who reported religious observance or beliefs, were less likely to report violence involvement. All violence-related behaviors were more common among male than female adolescents. CONCLUSIONS: Violence prevention efforts should begin in elementary school and continue throughout adolescence. Programs should be prepared to provide services or referrals to victims of violence, implement programs tailored toward females as well as males, and build partnerships with churches and other community organizations in which youth are involved.
Adolescent↗
Cholesterol lowering benefits of soy and linseed enriched foods.
Foods such as breads and breakfast cereals enriched with a combination of soy protein (soy grits and/or soy flour) and whole linseed are gaining popularity. Regular consumption of either whole grains or soy protein can lower risk factors for coronary heart disease. Furthermore, linseed is a rich source of the omega-3 fatty acid. alpha-linolenic acid (LNA), with purported cardiovascular benefits. The aim of this study was to determine the effect of daily consumption of soy and linseed containing foods and Canola (as an added source of LNA) on plasma lipid concentrations in 20 mildly hypercholesterolaemic postmenopausal women. Fasted blood samples were taken initially and after 3 and 8 weeks to assay plasma lipids and both plasma and erythrocyte membrane fatty acids. Urinary isoflavones were also measured. Data from 18 subjects were used for analysis. Plasma total, low-density lipoprotein (LDL) and non-high-density lipoprotein (HDL) cholesterol concentrations fell significantly (10, 12.5 and 12%, respectively) within 3 weeks. Although attenuated, there were still significant reductions in total and non-HDL cholesterol (5 and 6.5%, respectively) after 8 weeks of intervention. These reductions were associated with increases in urinary isoflavone excretion. This pilot study indicates that regular inclusion of foods containing soy and linseed in the diet may improve plasma lipids in subjects with hypercholesterolaemia.
Aged↗
A fractal approach to the features of speech consonants.
Fractal dimension (D) quantifies the roughness of a temporal signal and estimates its degree of freedom, allowing a good approach for its fluctuations. This present study of consonants follows the D-assessment of vowels which was presented at the Copenhagen Collegium Meeting. Using a 16 kHz time sampling the D-values of consonants were studied in the consonant-vowel context of the French language. Each consonant was pronounced four times by six males and six females. For D-measurement of long consonants the same method was used, i.e. the dyadic box-counting method and its 10 points of D-measurement (10pD) as that used for vowels. In the aim to approach infinitely small time scales, and to appreciate at least the tendency of the 10-point set, i.e. the D value to which tends this set, the slope of the three last points (3pD) was also calculated. For the plosion part of plosive consonants, a semi-continuous box-counting method devoted to the D-measurement of a short, single-dimension temporal signal was designed. This study consistently demonstrates that (i) there is a significant difference between males and females, as far as voiced and non-plosive consonants are concerned; (ii) plosive consonants are not fractal; (iii) among long consonants, D-value of fricatives are significantly different (p < 0.01), as far as 3pD measurement is considered; and (iv) in the case of nasal consonants [m] and [n], this categorization is efficient for both 3pD and 10pD measurements (p < 0.05). There results will be commented on and discussed with the aim of clinical use.
Adult↗
Loss of N-linked glycans in the V3-loop region of gp120 is correlated to an enhanced infectivity of HIV-1.
We describe mutants of human immunodeficiency virus type-1 (HIV-1) strain NL4-3, which are lacking the thirteenth, fifteenth, or seventeenth sites for N-linked glycosylation (g13, g15, g17) of the envelope protein gp120. All three sites are located within the hypervariable V3 loop region of gp120. Those mutants lacking carbohydrates g15 or combinations of g15/g17 showed markedly higher infectivity for GHOST cells (human osteosarcoma cells) expressing CXCR4 (GHOST-X4), compared to the fully glycosylated NL4-3 wild type virus. In addition, these mutants could also infect cells which exhibits low background expression of CXCR4, corresponding to <10% of that observed for GHOST-X4 cells. In addition to the enhanced infectivity observed, mutants lacking g15 and g17 showed increased resistance to inhibition by SDF-1, the natural ligand of CXCR4. Thus, loss of the oligosaccharides g15 and g17 in the V3 region of gp120 markedly influences CXCR4-specific infection.
Amino Acid Sequence↗
Attachment styles and personality disorders as predictors of symptom course.
Adult attachment styles and personality disorders (PDs) show some conceptual and empirical overlap and both may complicate the course of symptoms among psychiatric patients. In this naturalistic prospective study, 149 patients with affective, anxiety, substance use, and other disorders were interviewed shortly after entering treatment, which included psychotherapy, pharmacotherapy, or both. Follow-up interviews were conducted 6 and 12 months later. Attachment styles, DSM-III-R PDs, and symptoms were assessed using structured interviews and consensus ratings. At intake, borderline, avoidant, and dependent PD features correlated consistently with symptom severity and secure attachment correlated inversely with two of four symptom scales. Secure attachment was linked with greater relative improvement in global functioning and a more benign course of anxiety symptoms over 6 months. Borderline PD features predicted less relative improvement of depressive symptoms over 6 months. These findings clarify the relations between attachment styles and PD features and they point to potential mediators of treatment response.
Adult↗
Is stagnating flow in former feeding arteries an indication of cerebral hypoperfusion after resection of arteriovenous malformations?
OBJECT: The authors' goal in this study was to challenge the proposed mechanism of the occlusive hyperemia theory, in which it is asserted that stagnating flow in the former feeding arteries of cerebral arteriovenous malformations (AVMs) leads to parenchymal hypoperfusion or ischemia, from which postoperative edema and hemorrhage originate. METHODS: Cortical oxygen saturation (SaO2) was measured in 52 patients by using microspectrophotometry in areas adjacent to AVMs before and after resection. The appearance of the former feeding arteries was categorized as normal (Group A); moderately stagnating (Group B); and excessively stagnating (Group C) on postoperative angiographic fast-film series. Patients and SaO2 values were pooled accordingly and compared using analysis of variance and Duncan tests (p < 0.05). Angiographic stagnation times in former feeding arteries were correlated in a linear regression/correlation analysis with SaO2 data (p < 0.05). All values are given as the mean +/- standard deviation. The average median postoperative SaO2 in Group C (15 patients) was significantly higher than in Groups B (17 patients) and A (20 patients) (Group C, 75.2 +/- 8.5; Group B, 67.5 +/- 10.8; Group A, 67.1 +/- 12 %SaO2), as was the average postoperative increase in SaO2 (Group C. 25.9 +/- 14.9; Group B, 14.6 +/- 14; Group A, 11.1 +/- 14 %SaO2). Angiographically confirmed stagnation times were also significantly longer in Group C than in Group B (Group C, 5.6 +/- 2.5; Group B, 1.3 +/- 0.6 seconds). A significant correlation/regression analysis showed a clear trend toward higher postoperative SaO2 levels with increasing stagnation time. CONCLUSIONS: Stagnating flow in former feeding arteries does not cause cortical ischemia, but its presence on angiographic studies is usually indicative of hyperperfusion in the surrounding brain tissue after AVM resection. In the context of the pathophysiology of AVMs extrapolations made from angiographically visible shunt flow to blood flow in the surrounding brain tissue must be regarded with caution.
Adolescent↗
[Inner ear and subarachnoid spaces: relations and diseases].
The purpose of this article is to describe, with 5 clinical cases, the physiological communications between the inner ear and the subarachnoid spaces (SAS) and present the imaging features with regard to. Therefore we briefly illustrate abnormal communications between SAS and perilymphatic fluids in certain cochlear and internal acoustic meatus (IAM) malformations and their consequences. Imaging features may depict diffusion pathway of bacterial meningitis to membranous labyrinth via the cochlear aqueduct or via the IAM. Rarely, in some patients referred for cochleovestibular symptoms, imaging features may display skull base tumors involving the area of cochlear or vestibular aqueduct aperture. Therefore, in patients referred for cochleovestibular symptoms, MR and CT study should carefully scrutinise not only the IAM but also the aperture of the cochlear and the vestibular aqueducts and the cerebellopontine meninges.
Adult↗
Effect of nasal dilators on pleasantness, intensity and sampling behaviors of foods in the oral cavity.
The present study assessed the effect of nasal dilators on ratings of food intensity and pleasantness. Participants wearing the dilators rated foods in the oral cavity as less pleasant and more intense than did those participants wearing a placebo strip. In addition, they consumed less of the test stimuli. Significant interactions were noted between food stimuli and placebo vs. nasal dilator strip conditions, indicating certain food qualities, particularly initial pleasantness, combine to produce enhanced changes in perception. Changes in the intensity and pleasantness of foods was most pronounced in foods characterized as initially pleasant. A review of studies to date indicate that both foods and odors are perceived as more intense and less pleasant during nasal dilation, suggesting an impact of the dilators on both retronasal and orthonasal air flow.
Adolescent↗