PubMed Health⌕ Search

Biomedical subjects

N Q Nguyen

Publications and source records attributed to N Q Nguyen.

17 recordsLinked to original sources
PubMed2005

Assessment of oesophageal motor function using combined perfusion manometry and multi-channel intra-luminal impedance measurement in normal subjects.

Multichannel intraluminal impedance (MII) is being used increasingly to assess oesophageal bolus clearance. However, there is no good standardization of the impedance parameters that define 'effective bolus clearance'. The aim of this study was to define these important impedance parameters and to determine their normal values. Concurrent perfusion manometry and MII were performed in 42 healthy volunteers. Ten, 5-mL liquid (saline) boluses and then, 10x5-mL low impedance viscous boluses were tested in each subject in the right-lateral position. Normal values for bolus presence time (BPT) at each site and total bolus transit time (TBTT) were determined from either 'normal' peristaltic responses (amplitude>or=30 mmHg in distal oesophagus) or 'super-normal' peristaltic responses (amplitudes>or=50 mmHg at all sites). The relationship between BPT and TBTT within a response and per-individual performance was determined. A total of 840 swallows of liquids and viscous responses were analysed. BPT and TBTT of viscous swallows were longer than those for liquids. Non-peristaltic responses were significantly more likely not to clear a viscous than a liquid bolus. Within a response, the number of sites with prolonged BPT strongly predicted the incidence of prolonged TBTT. Using impedance criteria, normal oesophageal bolus clearance is defined when an individual completely clears at least 70% of liquid responses and at least 60% of viscous responses. This study provides normal values for impedance measurement of bolus clearance when combined with perfusion manometry. These values will allow standardization of impedance application in oesophageal function testing, in both research and clinical setting.

Adolescent↗
PubMed2000

Authors in Dermatologic Surgery.

Authors of scientific papers have been evaluated in the past by how frequently the medical literature cites them. In this analysis, we specifically identify those individuals who have contributed to the field of cutaneous surgery through publications in Dermatologic Surgery. We further analyze those publications frequently cited in Dermatologic Surgery, allowing us to determine topics of utmost value and interest. Using a citation database provided by the Institute for Scientific Information, we first identify all publications and citations from 1981 to 1999 for Dermatologic Surgery and the Journal of Dermatologic Surgery and Oncology (the previous name for this journal). Of the original articles published during this time frame, 3099 authors published 2167 papers. We quantify the publications from each author, and identify 57 authors with at least 10 original articles. When expanding the database parameters to include original articles, reviews, notes, and proceedings (as defined by the Science Citation Index), we find that the eight authors with the greatest number of publications are the same individuals with the greatest number of original articles. This reflects significant contributions to the field of cutaneous surgery by these authors. This analysis further identifies source papers for authors in Dermatologic Surgery. Publications frequently cited include those papers discussing laser surgery, with Dermatologic Surgery serving as the most frequently cited journal.

Authorship↗
PubMed1999

Subretinal lesions in subacute sclerosing panencephalitis.

Subacute sclerosing panencephalitis (SSPE) is a rare progressive neurologic disorder. A 9-year-old boy was seen who had progressive neurocognitive decline, myoclonic jerking of the extremities, and an abnormal result of an electroencephalogram (EEG). Ophthalmoscopic examination revealed multifocal subretinal lesions. The diagnosis of SSPE was made on the basis of the clinical examination and elevated serum and spinal fluid measles titer. We describe subretinal lesions in a patient with SSPE.

Child↗
PubMed1997

Bi-dimensional scaling map (BDS-Map): an approach for building large genetic maps.

MOTIVATION: The approaches usually used for building large genetic maps consist of dividing the marker set into linkage groups and provide local orders that can be tested by multi-point linkage analysis. To deal with the limitations of these approaches, a strategy taking the marker set into account globally is defined. RESULTS: The paper presents a new approach called 'Bi-Dimensional Scaling Map (BDS-Map) for inferring marker orders and distances in genetic maps based on the use of an additional dimension orthogonal to the map into which markers are projected. Dynamical forces based on a two-point analysis are applied to tend to optimize the marker locations in space. The efficiency of the approach is exemplified on real data (16 and 70 markers on chromosomes 6 and 2, respectively) and simulated data (50 maps of 70 markers).

Algorithms↗
PubMed1997

Diagnosis of enteric fever caused by Salmonella spp. in Vietnam by a monoclonal antibody-based dot-blot ELISA.

Enteric fever caused by Salmonella spp. is prevalent in Vietnam. None of the currently available diagnostic methods meets the ideal criteria on rapidity, simplicity, sensitivity, specificity, cost-effectiveness and practicality for developing areas. In this study, a recently developed monoclonal antibody-based dot-blot ELISA was used in comparison with the hemoculture method and the classical Widal test for diagnosis of salmonellosis in 171 Vietnamese patients presenting with clinical features of enteric fever. Urine samples of 50 healthy counterparts were used as negative controls. Salmonella spp. were isolated from 77 of 171 patients (45%) while 98 and 111 patients were positive by dot-blot ELISA and Widal test, respectively. The diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the ELISA performed on three serial urine samples collected at 2 hour intervals of the 171 patients were 92.2%, 71.3%, 80.7%, 72.4% and 91.8%, respectively when compared with the culture method. The Widal test performed on acute and convalescence serum samples showed 87.0%, 46.8%, 68.4%, 60.4% and 83.3% diagnostic sensitivity, specificity, accuracy, and positive and negative predictive values, respectively when compared with the bacterial culture method. Kappa coefficience revealed very good agreement beyond chance between the MAb-based ELISA and the culture method. The ELISA was not reactive when tested on urine samples of 50 healthy individuals which indicates 100% specificity. The Salmonella antigenuria of the patients as detected by ELISA lasted 10.3+/-3.9 days after initiating antibiotic treatment. The MAb-based dot-blot ELISA is easy to perform. It is rapid, sensitive, specific, inexpensive, and non-invasive and does not require equipment, thus is suitable for developing areas. It can detect acute/recent infection and can be used for evaluation of the efficacy of the treatment.

Adolescent↗
PubMed1994

Interactions between serotonin, thyrotropin-releasing hormone, and substance P in the CNS regulation of adrenocortical secretion.

Double-labeling immunohistochemical studies were performed to discern the morphological relationships between corticotropin-releasing factor-immunoreactive (CRF-ir) perikarya and afferent innervation in the hypothalamic paraventricular nucleus (PVN) of the rat. Attention was focussed on the local innervation by serotonin (5-hydroxytryptamine, 5-HT), thyrotropin-releasing hormone (TRH) and substance P (SP)-ir nerve terminal fibers. 5-HT-ir and SP-ir fibers were present in moderate numbers, in close apposition with CRF-ir perikarya. Sparse TRH-ir fibers were observed, but a population of TRH-ir perikarya was found in proximity with the CRF-ir cell bodies. TRH-ir perikarya in the PVN were surrounded by both 5-HT- and SP-ir fibers. Neuroendocrine studies were performed to investigate the interactions between 5-HT, TRH and SP in the regulation of hypothalamo-pituitary-adrenocortical (HPA) secretion. Male rats were prepared bearing cannulae for intracerebroventricular (ICV) or intra-PVN administration of drugs. 5-HT, at all doses tested (0.1, 40, or 80 nmol, ICV), caused increases in plasma corticosterone (CS) concentrations in tail-vein blood collected 20 min after injection. ICV injections of TRH caused dose-dependent increases in plasma CS, but did not further increase HPA responses when injected together with 5-HT. SP alone had little effect, although a significant reduction in plasma CS concentrations was observed in several individual experiments. However, SP (0.1 nmol) significantly attenuated CS responses following high doses of 5-HT (40 and 80 nmol, ICV), although the response to 0.1 nmol 5-HT was not affected. Combined injection of SP with TRH resulted in HPA responses not different from those following TRH alone. Similarly, SP did not reduce the HPA response observed with TRH and 40 nmol 5-HT in combination. Intra-PVN injections of 5-HT (0.1 or 40 nmol) and TRH also increased plasma CS concentrations. Intra-PVN injections of SP had little effect on plasma CS concentrations although a tendency toward a decrease in plasma CS was observed, as with the ICV injections. Combined intra-PVN injection of 5-HT (0.1 nmol) with TRH (0.1 nmol) did not significantly alter the response compared with that observed following TRH alone, although plasma CS concentrations were greater than with 0.1 nmol 5-HT. Combined intra-PVN injections of SP (0.1 nmol) with 5-HT (0.1 nmol) resulted in a significant decrease in plasma CS concentration compared with that following 5-HT alone, but SP did not prevent the CS response to a higher dose of 5-HT (40 nmol).(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenal Cortex↗
PubMed1992

[A fatal gas embolism during a hysteroscopy-curettage].

A 26 year old woman without any pathological history except metrorrhagia underwent a hysteroscopy under epidural anaesthesia and uterine cavity dilatation by saline solution. A respiratory distress and cardoffirculatory arrest occurred at the end of the procedure. Despite several attempts of cardiorespiratory resuscitation the patient deceased. The diagnosis retained was a gas embolism caused by blast effect from reintroduction of the hysteroscope into the uterine cavity. Different mandatory security measures are evoked.

Adult↗
PubMed1992

[A complication of epidural anesthesia: cerebral pneumatocele. A case report].

Having had a case themselves the authors report a rare complication of epidural anaesthetic, namely pneumocephaly. When it occurs it is usually after a difficult puncture; and usually thought of if headaches are unusually severe of there is a picture of intracranial rise in pressure. Then a tomodensitometry will lead to the diagnosis. Literature shows that it can be a serious condition, sometimes fatal, which means that the case has to be followed up very carefully and tomodensitometry has to be repeated until complete cure has been obtained.

Adult↗
PubMedDate not supplied

[Incident of intestinal parasitosis in Martinique].

A survey of intestinal parasitosis was conducted in Martinique by INSERM in 1978. The survey used a stratified sample of 823 households from the general population. The most prevalent parasitosis are: schistosomiasis 19%; ancylostomiasis 18%; trichuriasis 37%; ascaridiasis 7%; strongiloidiasis 3%. 70% of the 5 to 15 age group carries at least 1 parasite. The prevalence of trichuriasis, ascaridiasis and giardiasis is greatest in the 5 to 15 age group, Ancylostomiasis concerns mostly the 15 to 30 age group. Schistosomiasis, was most prevalent in adults over 30 years of age. Prevalence of parasitosis in rural regions is double that of urbanised regions. Schistosomiasis mostly occurs in the north. Ascaridiasis in the north-east. Rainfall and housing status, each influence on the rates of infestation.

Adolescent↗