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D T Nguyen

Publications and source records attributed to D T Nguyen.

At least 37 records · Page 2Linked to original sources
PubMed1998

A review of the present status of lymphatic filariasis in Vietnam.

Establishing the current status of an infectious disease forms the starting point of any attempt at parasite control. Although data on the prevalence and distribution of lymphatic filariasis exist for Vietnam from the early 1900s, the present situation regarding the disease is less well-known. Here, we review the results of recent surveys conducted by the Institute of Malariology, Parasitology and Entomology, Hanoi, to update the existing information on filariasis epidemiology and distribution for this country. The present results are from surveys carried out on some 135,000 individuals in 24 provinces of Vietnam. The highest prevalences of microfilaraemia (primarily Brugia malayi ) are observed in lowland areas of the Red River Delta and in Quang-binh Province where the survey results show microfilaraemia (mf) prevalences in the range of 0.9-5.5%. The most common type of chronic clinical manifestation is shown to be leg elephantiasis. A significant finding is that an overall decrease in mf prevalence was observed to occur in five communities which were surveyed twice over an 11-21-year period, even though no interventions were carried out between the two surveys. The changes are probably caused by environmental changes, such as increased standards of housing and drainage. Studies on the effect of selective chemotherapy and mass chemotherapy using diethylcarbamazine showed reductions in community mf prevalences of 69 and 72-88%, respectively. Furthermore, cats do not appear to represent significant reservoirs of infection. These findings of geographical restriction of infection, effective and well-tolerated drug therapy, low significance of animal reservoirs, together with the existence of an effective national health network, suggest a good prognosis for the control of filariasis in this country.

Animals↗
PubMed1998

Evaluation of the injured wrist on the field and in the office.

The wrist is a common site of injury in sports, both acute and chronic. Evaluation of wrist injuries requires knowledge of anatomy kinematics, attention to the mechanism of injury, the intensity of training, and a focus on the physical examination for specific injuries.

Athletic Injuries↗
PubMed1998

Anesthetic management of the patient undergoing head and neck cancer surgery.

The head and neck cancer patient should be in the best possible medical condition before facing surgery, bearing in mind the status of the tumor and the urgency of the procedure. Careful assessment of the patient's upper airway will enable the anesthesiologist to select an appropriate course of action to secure the airway before the operation begins. In many cases, the patient can be safely intubated after the induction of general anesthesia. In other situations, the patient may require an examination of the airway while awake with the aid of sedation and topical analgesia to determine the safest intubation technique. If the patient has evidence of a difficult airway, a flexible fiberoptic-guided intubation may be indicated to secure the airway in the awake patient patient before general anesthesia is induced. Some patients with severe airway obstruction or large, bulky supraglottic tumors usually undergo an initial tracheostomy with local anesthesia to secure the airway. Following surgery, extubation of the patient's trachea requires careful attention and may have to be performed over a jet-ventilating stylet.

Airway Obstruction↗
PubMed1997

Simulation of the enzyme reaction mechanism of malate dehydrogenase.

A hybrid numerical method, which employs molecular mechanics to describe the bulk of the solvent-protein matrix and a semiempirical quantum-mechanical treatment for atoms near the reactive site, was utilized to simulate the minimum energy surface and reaction pathway for the interconversion of malate and oxaloacetate catalyzed by the enzyme malate dehydrogenase (MDH). A reaction mechanism for proton and hydride transfers associated with MDH and cofactor nicotinamide adenine dinucleotide (NAD) is deduced from the topology of the calculated energy surface. The proposed mechanism consists of (1) a sequential reaction with proton transfer preceding hydride transfer (malate to oxaloacetate direction), (2) the existence of two transition states with energy barriers of approximately 7 and 15 kcal/mol for the proton and hydride transfers, respectively, and (3) reactant (malate) and product (oxaloacetate) states that are nearly isoenergetic. Simulation analysis of the calculated energy profile shows that solvent effects due to the protein matrix dramatically alter the intrinsic reactivity of the functional groups involved in the MDH reaction, resulting in energetics similar to that found in aqueous solution. An energy decomposition analysis indicates that specific MDH residues (Arg-81, Arg-87, Asn-119, Asp-150, and Arg-153) in the vicinity of the substrate make significant energetic contributions to the stabilization of proton transfer and destabilization of hydride transfer. This suggests that these amino acids play an important role in the catalytic properties of MDH.

Binding Sites↗
PubMed1997

Fast separation of underivatized carbohydrates by coelectroosmotic capillary electrophoresis.

A method for the rapid quantitative analysis of underivatized acidic sugars, monosaccharides and disaccharides using coelectroosmotic capillary electrophoresis was developed. Indirect UV detection at 254 nm using sorbate as background electrolyte was employed for monitoring the analytes. A highly alkaline pH value of the electrolyte system was chosen in order to achieve an electrophoretic mobility of the saccharides towards the anode. A dynamic reversal of the electroosmotic flow and, by this means, a codirectional movement of the negatively charged analytes and the electroosmotic flow is accomplished by employing a polycationic surfactant (hexadimethrine bromide), which is added to the background electrolyte. To further improve the resolution of specific carbohydrates, acetone is used as organic modifier. A practical application of the developed method for the fast determination of fructose, glucose, and sucrose in various soft drinks is provided.

Acetone↗
PubMed1997

A comprehensive knowledge-based system for laboratory hematology.

The Coulter FACULTY knowledge-based systems, Professor Petrushka for peripheral blood interpretation, Professor Fidelio for flow cytometry immunophenotyping and Professor Belmonte for bone marrow reporting, have been installed in several hospitals in Spain, Portugal and the United Kingdom. In Spain and Portugal, the systems are part of the IZASA-Coulter CITOTECA workstation, which includes a video camera for capturing microscopic images and a networkable laboratory information system supporting color reports. At the Royal Hospitals Trust (St. Bartholomew's Hospital and The Royal London Hospital, London, UK), networked workstations are available and the system is used daily to generate bone marrow reports in the hematology laboratories. There have been considerable benefits from adopting Coulter FACULTY for bone marrow reporting, including faster turnaround time, improved quality of the reports and cost savings.

Artificial Intelligence↗
PubMed1997

Haematological validation of a computer-based bone marrow reporting system.

AIMS: To prove the safety and effectiveness of "Professor Belmonte", a knowledge-based system for bone marrow reporting, a formal evaluation of the reports generated by the system was performed. METHODS: Three haematologists (a consultant, a senior registrar, and a junior registrar), none of whom were involved in the development of the software, compared the unedited reports generated by Professor Belmonte with the original bone marrow reports in 785 unselected cases. Each haematologist independently graded the quality of Belmonte's reports using one of four categories: (a) better than the original report (more informative, containing useful information missing in the original report); (b) equivalent to the original report; (c) satisfactory, but missing information that should have been included; and (d) unsatisfactory. RESULTS: The consultant graded 64 reports as more informative than the original, 687 as equivalent to the original, 32 as satisfactory, and two as unsatisfactory. The senior registrar considered 29 reports to be better than the original, 739 to be equivalent to the original, 15 to be satisfactory, and two to be unsatisfactory. The junior registrar found that 88 reports were better than the original, 681 were equivalent to the original, 14 were satisfactory, and two were unsatisfactory. Each judge found two different reports to be unsatisfactory according to their criteria. All 785 reports generated by the computer system received at least two scores of satisfactory or better. CONCLUSIONS: In this representative study, Professor Belmonte generated bone marrow reports that proved to be as accurate as the original reports in a large university hospital. The haematology knowledge contained within the system, the reasoning process, and the function of the software are safe and effective for assisting haematologists in generating high quality bone marrow reports.

Bone Marrow↗
PubMed1997

[Access to health care for destitute persons at Public Assistance Hospitals in Paris].

All legal French residents are entitled to health care. The 1992 regulatory measures, which create a contractual agreement between the government and public medical institutions, aim at facilitating access to health care by resolving the financial obstacles to accessing health care. The Assistance Publique-Hôpitaux de Paris (AP-HP) has set up a medical reception center in several hospitals since 1993. This system is integrated in the general structure of each hospital: in some cases, there is a single and centralized unit; in other cases, all departments of the hospital, including the emergency room, are involved in caring for destitute patients. Whatever the type of the structure may be, social workers are a key element to helping the patients recover their social rights. Thirty to seventy-percent of patients visiting these centers regain access to social and health care coverage. The epidemiological survey of the active file of patients revealed that 70% are male, more than 50% are non-French nationals, half of which do not have legal immigration status in France. Homeless people represent 40 to 80% of the population. The average age is around 35. The number of medical visits varies greatly from one hospital to another and range from 20 to 60 per month. The reasons for visiting the center and the identified medical disorders are strongly related to the patients' life conditions and vary significantly with the risk factors related to the social and economic situation. The frequency of some diseases (psychiatric disorders, tuberculosis, infections by the HIV and HCV) is higher in this population than in general population. Delayed visits to the medical center represents a severity factor. The hospitals' mission statement is not only to ensure that patients facing a precarious social and professional situation have equal access to health care, but also to help such patients recover their social rights, facilitate their integration in the society and fight against social exclusion.

Health Services Accessibility↗
PubMed1996

Effects of earplugs on catecholamine and cortisol excretion in noise-exposed textile workers.

To investigate physiological and psychological effects of industrial noise, a survey was performed on 50 female workers exposed to machinery noise [93-100 dB(A)] (noise group) and 25 female workers in less-noisy environments [71-75 dB(A)] (control group) in a textile factory in Vietnam. Urine was collected for analysis of catecholamines and cortisol. The subjects were also asked to fill out a questionnaire. Each subject was examined over 2 working days. The workers in the noise group were asked to put earplugs in their ears during the working hours of the 2nd day. On the 1st day without earplugs, urinary excretion of catecholamines in the noise group were greater than those in the control group. Cortisol in urine showed a similar tendency. Differences in catecholamine excretion between the noise group and the control group decreased on the 2nd day when the earplugs were used for attenuation of noise level in the noise group. Frequency of subjective fatigue symptoms was lower on the 2nd day than that on the 1st day in noise group, while the control group showed almost no day-difference. The results indicate that the catecholamine response to noise in workers was reduced through the use of earplugs.

Adult↗
PubMed1996

Differential diagnosis of L26-positive, CD15-negative Hodgkin's disease and large B-cell lymphoma with a high content of reactive T-cells: a morphologic and immunohistochemical study.

B-cell non-Hodgkin's lymphomas with a marked preponderance of reactive T cells, so-called T-cell rich B-cell lymphomas (TCRBCLs), can be morphologically confused with Hodgkin's disease (HD). To establish helpful distinguishing features in paraffin sections, 10 cases of L26-positive, CD15-negative HD and 10 cases of TCRBCL were compared; 4 cases of HD had morphologic features of the nodular lymphocyte predominant (LP) type. Nine of 10 cases of HD contained fewer than 20 mitoses/20 high power fields (hpf) and only 1 had pericapsular involvement. In contrast, 9 of 10 TCRBCL had greater than 20 mitoses/20 hpf and 7 had perinodal infiltration. HDLP was easily distinguished from TCRBCL by the expanded dendritic meshworks outlining the L & H nodules and the high content of CD57-positive lymphocytes. The remaining 6 cases of non-LP L26-positive HD had a relatively distinctive immunostaining pattern, with absence of CD45 and discordant reactivity for L26 and Ki-B5 in Reed-Sternberg cells and variants. Only 3 cases of TCRBCL had a similar CD45 and L26/Ki-B5 immunostaining pattern, and these could be distinguished by demonstrable cytoplasmic light-chain restriction. These results show that evaluation of the mitotic count, pericapsular involvement, and immunohistochemical staining patterns for Ki-M4p, CD57, L26/Ki-B5, and CD45 can help to discriminate TCRBCL from L26-positive HD when only fixed material is available.

Adult↗
PubMed1995

Chronic lymphocytic leukemia with an interfollicular architecture: avoiding diagnostic confusion with monocytoid B-cell lymphoma.

Certain low grade B-cell lymphoproliferative disorders can be mistaken for each other morphologically, particularly when there is partial lymph node involvement. We encountered two cases of chronic lymphocytic leukemia, in which the interfollicular growth pattern and the pale appearance of the neoplastic proliferation in the lymph nodes led to a misclassification as monocytoid B-cell lymphoma. The correct diagnosis was established, however, when the lymph node morphology was carefully reexamined, with the knowledge of the clinical history, peripheral blood findings, and bone marrow data. The immunophenotype of the neoplastic cells in the peripheral blood (CD5, CD23, weak fluorescence intensity of surface immunoglobulin and CD22) and the lymph node immunohistochemistry (weak L26 staining, strong MT1 positivity) confirmed the diagnosis of chronic lymphocytic leukemia. These two cases demonstrate the necessity of a systematic approach to lymph node morphology and the utility of a multiparameter approach in the diagnosis of lymphoproliferative disorders.

Aged↗
PubMed1995

An automated hematology laboratory with computer-controlled robotics.

A highly automated hematology laboratory environment is described that has conveyance systems to move bar-coded specimens from one station ("workcell") to another, robotic handling devices to load and unload hematology analyzers, and a hematology workstation. Computer systems monitor the process and equipment, track the specimen, manage inventory, and interpret patient results. When a specimen arrives at the laboratory, the bar-code determines which workcell the specimen should go to for testing. Each specimen is handled individually and in real-time. Hematology specimens are routed to a workcell of Coulter STKS analyzers where complete blood counts with five-part leukocyte differentials are performed under full robotic control. The entire process is managed by a real-time Windows-based process control system that interacts with a networked laboratory information system. The hematology workstation is being evaluated for interpretive results reporting and to determine follow-up testing.

Clinical Laboratory Information Systems↗
PubMed1994

A knowledge-based system for the interpretation of flow cytometry data in leukemias and lymphomas.

Flow cytometry immunophenotyping and analysis of DNA ploidy and proliferative activity have become extremely helpful techniques for diagnosing and subclassifying hematopoietic cell populations in a modern, full-service hematopathology laboratory. The number of physicians with special training in the interpretation of these studies is limited. A knowledge-based computer system has been designed to aid in the interpretation of immunophenotyping and DNA flow cytometry results in hematopoietic disease. The system, known as "Professor Fidelio," is a heuristic classification system that reasons on the basis of defined diagnostic patterns. In this study, Fidelio was tested as a stand-alone system on 366 specimens from two large tertiary medical centers. Fidelio's interpretation was considered to be appropriate in all cases. In 300 of 366 (82%) specimens, the system's interpretation agreed with the diagnosis of record. Many of the disagreements could be traced to errors in the recording of the original diagnosis and minor differences in diagnostic criteria between Fidelio's knowledge base and the criteria in use at the medical centers. When used in a stand-alone mode, Fidelio's interpretation was less specific than the diagnosis of record in certain lymphoproliferative disorders that require morphologic information for subclassification. Professor Fidelio is one module in a workstation for the diagnostic hematology laboratory. This workstation is designed for interpretive reporting, education, and database functions for clinical research. Clinical and morphologic information are shared between Fidelio and the other modules for peripheral blood analysis, bone marrow morphology, and lymph node interpretation by means of a relational database. The system will be useful in hospitals that lack individuals specially trained in flow cytometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Artificial Intelligence↗
PubMed1994

Balloon dissection facilitated laparoscopic extraperitoneal hernioplasty.

BACKGROUND: With the goals of minimizing perioperative morbidity and obtaining direct inguinal access without transgressing the peritoneal cavity, we developed a balloon dissection device to facilitate laparoscopic extraperitoneal hernioplasty. PATIENTS AND METHODS: We have performed balloon facilitated dissection on 113 patients (105 males) on an outpatient basis. Some patients were repaired under regional anesthesia. A total of 150 hernias have been repaired: 72 indirect, 70 direct, 3 scrotal, 2 sliding, 2 spigelian, and 1 femoral. RESULTS: Mean operating time was 60 minutes. All patients were ambulatory on discharge. Half reported minimal or no immediate postoperative pain. Over 80% had only minimal irritation or discomfort on the third postoperative day. Nearly 60% returned to work within 2 weeks. None required hospital readmission for an immediate complication of hernioplasty. With a mean follow-up of 6.3 months, only three recurrences are reported. Except for one persistent neuropathy which resolved after staple removal, there were no significant complications. CONCLUSIONS: We conclude that balloon dissection facilitates laparoscopic extraperitoneal hernioplasty and obviates the need for general anesthesia. Our approach minimizes perioperative pain. It can be done on an outpatient basis and permits prompt return to full activity including physical work.

Adult↗
PubMed1994

Castleman's disease. Differences in follicular dendritic network in the hyaline vascular and plasma cell variants.

Twenty-seven cases of the hyaline vascular variant and 10 cases of the plasma cell variant of Castleman's disease were studied with the paraffin resistant monoclonal antibodies Ki-FDC1p and/or Ki-M4p against follicular dendritic cells. Studies with the monoclonal antibody Ki-M9, for the detection of sinus lining cells, were also performed on the available frozen tissue in four cases of the hyaline vascular variant. In nine of the 10 plasma cell variant cases, the predominant type of follicular dendritic cell network was similar to that seen in normal or reactive germinal centres. In contrast, the hyaline vascular variant demonstrated either an expanded, disrupted, follicular dendritic cell network (10 cases) or multiple tight collections of follicular dendritic cells (16 cases). Sinus lining cells were not detected in the four cases studied. The difference in the predominant type of dendritic meshwork is an additional distinguishing feature to separate the plasma cell and hyaline vascular variants of Castleman's disease. The patterns of dendritic network seen in the hyaline vascular type, together with the absence of sinus lining cells, appear to favour the hamartoma theory proposed for this variant.

Castleman Disease↗