[The oesophageal arteries of cervical origin. An anatomical study of 23 dissected preparations (author's transl)].
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Aged↗
Biomedical subjects
H Nguyen
Publications and source records attributed to H Nguyen.
[The muscular atrioventricular septum].
On the left ventricle septal wall, the tricuspid valve ring attachment is displaced forward, towards the cardiac apex. To this trapezoïdal area between the two atrio-ventricular annuli, the medial wall of the right atrium is attached (laminar attachment), resulting in a atrio-ventricular septum which is: --membranous at its superior extremity (membranous atrio-ventricular septum well described in all classical anatomy textbooks); --and muscular at its inferior extremity. Located in the inferior anterior portion of the Koch triangle, the muscular atrio-ventricular septum is roughly triangular in shape. Its superior and anterior borders are well delineated and represented by: --the pars muscularis crest, at its junction with the membranous atrio-ventricular septum; --and the insertion of the tricuspid septal leaflet on this pars muscularis of the inter-ventricular septum. On the contrary, its third border, the posterior inferior left, is not well defined and varies greatly with the amount of fat filling the crux of the heart. The atrio-ventricular septum separates the right atrium from the base of the left ventricle outflow tract. It shares the important relationship of the "carrefour" of the four cardiac chambers (7 - 8) and first of all the conduction system and its vascular supply. The concept of an atrio-ventricular septum, both muscular and membranous, is to be kept in mind for the good understanding and the surgical correction of different types of "common atrio-ventricular canal" (2 - 10).
Heart Septum↗
[Microsurgical anatomy of the main trunk of the postero-inferior cerebellar artery. 22 microdissections].
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Aged↗
[The lashes. Physiology, structure, pathology (author's transl)].
In spite of the similarity between hairs and eyelashes the later shows several physiological and anatomical particularities. We performed an ultrastructural study of eyelashes and reviewed their pathology.
Anoplura↗
Aflatoxin content of foods served to a population with a high incidence of hepatocellular carcinoma.
During three seasons, 36 samples of foods served to mentally retarded clients with a high incidence of hepatocellular carcinoma were analyzed for aflatoxin. Aflatoxin was not detected (less than 5 ppb) by thin-layer liquid chromatography in 35 food samples containing peanuts, corn, wheat or milk. One peanut butter sample contained 20 ppb aflatoxin. Aflatoxin content of these foods was at or below the level permitted by the Food and Drug Administration. Aflatoxin is probably not responsible for liver disease in this population.
Aflatoxins↗
Effects of contrast dose, delayed imaging, and magnetization transfer saturation on gadolinium-enhanced MR imaging of brain lesions.
This paper discusses the types of paramagnetic agents available for clinical brain imaging and reviews investigations that have sought to optimize the use of these agents by varying the administered dose, delaying the imaging time after contrast administration, and altering image contrast by using magnetization transfer saturation pulses.
Blood-Brain Barrier↗
Initial evaluation and management of upper airway injuries in trauma patients.
STUDY OBJECTIVE: To examine and compare the mechanism of injury, diagnostic findings, initial methods of airway management, and outcome of patients who had upper airway injuries. DESIGN: A retrospective review of hospital records. SETTING: A large metropolitan, university-affiliated trauma center. PATIENTS: Forty-six cases of upper airway injuries admitted between 1984 and 1988. INTERVENTIONS: Diagnostic methods included clinical examination, cervical and thoracic radiographs, bronchoscopy and computerized tomographic (CT) scan. Therapeutic interventions ranged from conservative management with or without endotracheal intubation to operative reconstruction. MEASUREMENTS AND MAIN RESULTS: Mechanism of injury was knife stab wound in 9 cases, gunshot wound in 17 cases, and blunt trauma in 20 cases. Location was the larynx in 13 cases, trachea in 24 cases, cricoid cartilage in 5 cases, and multiple sites in 4 cases. Diagnostic findings varied considerably according to the mechanism of injury, but radiographic evidence of soft tissue air and wounds opening into the airway were common findings. CT scan and bronchoscopy also were useful diagnostic tools. Overall mortality was 24%, which did not vary according to patient age or mechanism of injury. The airway injury itself was a primary or contributory cause of death in four cases, two of which were tracheal injuries and two injuries at the cricotracheal junction. CONCLUSIONS: In any patient with possible upper airway injury, plain radiographs of the chest and neck should be obtained to aid in the diagnosis. Elective intubation should be attempted only with a surgical team present and prepared for emergency tracheotomy. Fiber-optic bronchoscopy could be a valuable aid for both intubation and evaluation in such cases.
Cricoid Cartilage↗
Reflex responses associated with activator treatment.
BACKGROUND: Previous studies have demonstrated the existence era reflex response, measurable by surface electromyography (sEMG), after manually delivered spinal manipulative therapy (SMT). This reflex response has been characterized as consistent, reproducible within individual subjects, and nonlocal because it extends beyond the site of manipulation. However, the nature and magnitude of possible reflex responses in the paraspinal and proximal limb muscles elicited by nonmanual SMT, such as with an adjusting instrument, remain unknown. OBJECTIVE: To characterize the reflex responses associated with SMT by using sEMG to record the responses of 16 muscles before, during, and after treatment. STUDY DESIGN: The eleetromyographic responses of 16 para-spinal and proximal limb muscles in 9 healthy, asymptomatic male volunteers were measured simultaneously by sEMG before, during, and after chiropractic SMT. METHODS: SMT thrusts were delivered to 9 asymptomatic volunteers at 6 bilateral sites (C3/4, T2/3, T6/8, T11/12, L2-4, and s1). Reflex responses were measured from 16 muscles with bipolar sEMG electrodes and collected at 2000 Hz per channel with data acquisition software. RESULTS: Approximately 68% of the SMT thrusts resulted in a detectable reflex response. The cervical spine resulted in a detectable response of 50%, thoracic spine 59%, lumbar spine 83%, and sacroiliac joints 94%. Treatments delivered to the thoracic spine elicited the largest peak-to-peak amplitude sEMG responses, whereas the lumbar spine demonstrated the most heterogeneous responses. When a reflex response was observed, it always occurred close to the treatment site ipsilaterally and was detected in muscles that had either their origin or insertion at the vertebral level that was adjusted. CONCLUSIONS: Based on the local nature, magnitude, and characteristic shape of all reflex responses observed, we hypothesized that they were likely generated by a single proprioceptor. Furthermore, the temporal properties of this reflex response suggest that they originated from the muscle spindles. In contrast to previous observations on reflex responses after manual SMT, these treatments elicited reflex responses that varied between subjects but were consistent within an individual and were local in nature. We conclude that SMT delivered in this manner results in a reflex response that is both quantitatively and qualitatively different from a manual SMT.
Adult↗
Drug use behaviors among Asian drug users in San Francisco.
Due to a pervasive bias toward Asian Americans, such as tendency to view Asian Americans as model minorities, drug use behaviors among them are often ignored by health professionals, researchers, and community members, including Asian community members. This study identified patterns of drug use behaviors in relation to cultural factors among Asian drug users in San Francisco, CA. A sample of 92 Asian drug users (35 Chinese, 31 Filipino, 26 Vietnamese) who were not currently enrolled in drug treatment programs were recruited through targeted sampling methods and interviewed using a questionnaire with open-ended questions. The study evaluated responses of the participants and used content analyses. This study clearly revealed that the patterns of drug use among Asian drug users are unique to their ethnicity, gender, immigrant status, and age groups. Also, Asian drug users share cultural constructs related to drug use such as fear of addiction and injecting drugs, and stigma attached to drug users in the community. Therefore, drug abuse prevention programs should address both common factors among Asian drug users, as well as unique factors in specific target groups (e.g., ethnic groups, Asian immigrants, Asian women, refugees, and adolescents).
Adult↗
Caring for Houston's Vietnamese population.
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Asian↗
Effect of local corticosteroids on early inflammatory function in surgical wound of rats.
To investigate the effects of local corticosteroids during the early inflammatory process in iatrogenically induced surgical wounds, three different types of corticosteroids, dexamethasone sodium phosphate (Decadron), betamethasone sodium phosphate (Celestone Phosphate), and betamethasone sodium phosphate-acetate (Celestone Soluspan), were evaluated using rats. Single doses of corticosteroid were administered locally to male Sprague-Dawley rats after the surgical implantation of a wound chamber, which was used to collect fluid from the surrounding surgical wound. Wound fluids were drawn from the wound chamber at postoperative days 1, 3, and 5 and analyzed for total white blood cells (WBCs) and differential count. In this study, the authors have demonstrated that the corticosteroids (dexamethasone sodium phosphate, betamethasone sodium phosphate, betamethasone sodium phosphate-acetate) cause at least 50% reduction in the total circulating WBCs at the surgical wound site on postoperative day 1, followed by decreased reductions on days 3 and 5.
Adrenal Cortex Hormones↗
Modification of enzyme activity in reversed micelles through clathrate hydrate formation.
The physical phenomenon of clathrate hydrate formation in protein-containing reversed micelles is described. Hydrate formation in reversed micelles is a method of adjusting the water to surfactant molar ratio, wo, which influences micellar size. Lipase and alpha-chymotrypsin encapsulated in large reversed micelles of high wo show significant enhancements in activity when the micelle size is reduced through hydrate formation. Alternate methods of micelle size adjustments also show enhancements in activity. The implications for improving the activity of such encapsulated enzymes recovered from fermentation media through phase transfer into reversed micelles are discussed.
Chymotrypsin↗
Protein recovery from reversed micellar solutions through contact with a pressurized gas phase.
We describe a new process for the recovery of encapsulated protein from reversed micellar solution in concentrated form. The method involves desolubilization of the protein by decreasing solvent density through gas dissolution. Under appropriate thermodynamic conditions, the micellar water pool can be converted to clathrate hydrates. Protein recovery is facilitated by clathrate hydrate formation, which causes the desolubilized protein to exist in a solid phase, distinct from the micellar supernatant. The process is carried out without any ionic strength or pH modification.
Dioctyl Sulfosuccinic Acid↗
Rapid method for the solid-phase extraction and GC-MS analysis of flunitrazepam and its major metabolites in urine.
Recently, flunitrazepam (Rohypnol) has become an increasingly popular drug of abuse among young adults, who take it for its euphoric effects. In other cases, the drug has been used by rapists for its sedative and hypnotic effects that can induce a catatonialike trance and memory loss in potential victims; as a result, it has been nicknamed the "date-rape drug". For these reasons, the Drug Enforcement Administration recently considered adding the drug (a.k.a. "Roofies") to the same category as heroin and LSD. A selective and sensitive technique has been developed for extracting, detecting, and identifying flunitrazepam and its two major metabolites (7-aminoflunitrazepam and N-desmethylflunitrazepam) in human urine. Using a solid-phase extraction cartridge containing a "mixed-mode" bonded silica gel (Bond Elut Certify), flunitrazepam and its metabolites were selectively isolated from other urine components and quantitated and identified by gas chromatography-tandem mass spectrometry with a benchtop ion mass spectrometer. The extraction method is rapid, reproducible, and precise, and it has a broad linear working range. The overall extraction efficiency was found to be more than 90% for the parent drug as well as the two major metabolites.
Flunitrazepam↗
Dyspnea and the affective response during exercise training in obstructive pulmonary disease.
BACKGROUND: Dyspnea (SOB), dyspnea-related anxiety (DA), and exercise performance have been shown to improve after exercise training in patients with Chronic Obstructive Pulmonary Disease (COPD). However, there are no published descriptions of the changes in dyspnea intensity or dyspnea-related anxiety during or across the exercise training sessions. OBJECTIVES: To describe and compare the differences in the patterns of change in SOB, DA, and exercise performance during 12 exercise training sessions with and without nurse coaching. METHODS: Forty-five dyspnea-limited patients with COPD were randomly assigned to nurse-monitored (ME) or nurse-coached exercise (CE). SOB and DA were rated on a 200 mm VAS every 2 minutes during each of 12 treadmill training sessions. RESULTS: Warm-up, peak, cool-down, mean SOB, and peak SOB/stage remained constant over the exercise sessions, with increasing exercise performance for both groups over the 12 sessions (p < .001). There was a significant difference in the pattern of mean SOB over time between the ME and CE group (p < . 05). Mean, peak DA, and peak DA/stage showed a rapid decrease within the first 4 sessions (p < . 05) with no significant differences between the groups. Warm-up and cool-down DA remained constant. There were large intra- and inter-subject variations in the rating of dyspnea and dyspnea-related anxiety within and across sessions. CONCLUSIONS: As theoretically proposed, both groups significantly decreased their DA over the training sessions. This decrease was early in the sessions and was not accompanied by a decrease in the SOB. In contrast, subjects maintained a nearly constant mean and peak SOB with increasing exercise performance, suggesting that people may have a dyspnea threshold above which they are unable to tolerate greater dyspnea. Description of the changes in dyspnea and the affective response during training need to be expanded, while studying the type and timing of strategies to enhance the improvement in dyspnea and dyspnea-related anxiety.
Aged↗
Rapidly polymerized collagen gel as a smoothing agent in excimer laser photoablation.
BACKGROUND: Excimer laser photoablation effectively and precisely removes corneal tissue but may not smooth irregularities on the anterior corneal surface. An even surface might be obtained by applying a smoothing substance that fills in irregularities and ablates at the same rate as corneal tissue. Evaluation of collagen gel as a smoothing agent is reported. METHODS: Pure, type I collagen solutions were prepared to remain soluble at physiological pH and to spontaneously gel when exposed to cationic buffers. Collagen gels were formed on the surface of enucleated porcine corneas and on human donor corneas and exposed to varying pulses of 193-nanometer excimer laser energy. Effects of collagen gel on ablation depth, corneal surface smoothness, and smoothing of roughened cornea were evaluated by examining scanning electron micrographs of control and treated specimens. RESULTS: Collagen gels formed from 5 mg/ml collagen solutions dramatically altered the depth of photoablation. Photoablation of roughened cornea with collagen gels produced smooth corneal surfaces, whereas control eyes remained roughened and irregular. The smoothness of photoablated cornea surfaces improved when collagen gels were applied prior to photoablation. CONCLUSIONS: The rapidly gelling collagen solution appears to exhibit the functional properties required for an effective smoothing agent for excimer laser photoablation. The substance has low viscosity when applied to the corneal surface and forms a rigid gel when exposed to cationic buffer solution. In addition, the concentration of the collagen gel can be adjusted to provide different ablation rates.
Animals↗
[Absorbable synthetic clips and pulmonary excision].
From the beginning of this decade, two new, 2nd generation, resorbable synthetic materials--polydioxanone and lactomer--have been able to be molded into clips which, in contrast to metallic clips, are fitted with an original locking system preventing any slipping, either transversal or longitudinal, on the vessels. An experimental study was conducted to confirm their great reliability and perfect safety on large vessels (up to 8-9 mm) of large laboratory animals--both pulmonary and systemic vessels. Positive results justified their application to pulmonary vessels in humans during surgery, the pulmonary vessel being at a much lower pressure than in the main circulatory system. These new clips possess the advantages of metallic clips and resorbable synthetic threads without their inconveniences: rapidity, simplicity and ease of application, radio-transparency and complete inertia in magnetic fields enabling radiotherapy and modern postoperative investigations (scanner, NMR...) to be carried out.
Absorption↗
Refractive corneal surgery with the Draeger rotary microkeratome in human cadaver eyes.
BACKGROUND: Instrumentation for performing a uniform lamellar keratoplasty has been undergoing various stages of refinement. Reliable reproduction and uniform thickness and diameter of lamellar resections is required before lamellar refractive keratoplasty can be considered safe and effective. METHODS: The authors used the Draeger rotary microkeratome with mechanical blade advance for lamellar dissections in 61 human cadaver eyes prepared by injecting Swinger-Kornmehl (SK) solution into the anterior chamber to a pressure of 35 to 40 mm Hg and by soaking for 30 minutes in SK solution. Spacer sizes of 0.25 to 0.40 units were utilized using an anterior lamellar disc diameter estimate between 8.0 and 8.5 mm and a stromal lamellar disc diameter estimate between 5.5 and 6.5 mm. Preoperative pachometry, anterior and stromal lamellar disc thicknesses, and anterior and stromal lamellar disc diameters were measured. RESULTS: The Draeger unit created anterior lamellar thickness between 100 and 268 microns. Stromal lamellar disc thicknesses were consistently between 90 and 161 microns. The continuous, unidirectional, rotary blade and the uniform mechanical advance of the instrument produced a generally uniform bed as evaluated by scanning electron microscopy, although undulations were still present. CONCLUSION: The Draeger microkeratome produced regular lamellar dissections; however, predictability of the thickness of the lenticules varied 10% to 20%, and of the diameter, 1.5% to 15%. Predictability improved with experience. This variability may reduce predictability of refractive outcome.
Cornea↗