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Biomedical subjects

H D Tran

Publications and source records attributed to H D Tran.

10 recordsLinked to original sources
PubMed2001

Neutrophils employ the myeloperoxidase system to generate antimicrobial brominating and chlorinating oxidants during sepsis.

The myeloperoxidase system of neutrophils uses hydrogen peroxide and chloride to generate hypochlorous acid, a potent bactericidal oxidant in vitro. In a mouse model of polymicrobial sepsis, we observed that mice deficient in myeloperoxidase were more likely than wild-type mice to die from infection. Mass spectrometric analysis of peritoneal inflammatory fluid from septic wild-type mice detected elevated concentrations of 3-chlorotyrosine, a characteristic end product of the myeloperoxidase system. Levels of 3-chlorotyrosine did not rise in the septic myeloperoxidase-deficient mice. Thus, myeloperoxidase seems to protect against sepsis in vivo by producing halogenating species. Surprisingly, levels of 3-bromotyrosine also were elevated in peritoneal fluid from septic wild-type mice and were markedly reduced in peritoneal fluid from septic myeloperoxidase-deficient mice. Furthermore, physiologic concentrations of bromide modulated the bactericidal effects of myeloperoxidase in vitro. It seems, therefore, that myeloperoxidase can use bromide as well as chloride to produce oxidants in vivo, even though the extracellular concentration of bromide is at least 1,000-fold lower than that of chloride. Thus, myeloperoxidase plays an important role in host defense against bacterial pathogens, and bromide might be a previously unsuspected component of this system.

Animals↗
PubMed1998

Accuracy and clinical utility of the mini-dose 14C-urea breath test in the evaluation of Helicobacter pylori infection.

The aim of this study was to evaluate the accuracy of the 14C-urea breath test by comparing the results to those obtained by endoscopy with mucosal biopsy. We also examined the value of the breath test result obtained prior to endoscopy in predicting peptic ulcer disease. Forty-two individuals underwent the 14C-urea breath test. Collections of expired C02 were analysed using a liquid scintillation counter. All individuals then underwent endoscopy with biopsy. Biopsy material was evaluated by the rapid urease method and by histology for the presence of H. pylori. Our results demonstrated that the 14C-urea breath test was 100% sensitive and specific when compared to the rapid urease test as the 'gold standard' for the detection of H. pylori. In comparison to pathology, the sensitivity remained 100% and the specificity was 89%. The results of the 14C-urea breath test had a poor predictive value for the determination of peptic ulcer disease. We conclude that the 14C-urea breath test can be easily performed at any medical facility equipped with a liquid scintillation counter and can accurately detect H. pylori. A negative breath test result could not exclude the presence of peptic ulcer disease.

Adult↗
PubMed1995

A comparative study of family functioning among Vietnamese and Cambodian refugees.

This study was designed to determine the extent of family problems among a clinic population of Cambodian and Vietnamese refugees, and to identify similarities and differences between the two groups. All 107 patients with adolescent children from a total clinic population of 298 were interviewed using a semistructured questionnaire, results were tabulated, and statistical methods were applied. The types of problems with children described by parents were classified into the dimensions of communication, personal behaviors, school performance, social behaviors, and antisocial behaviors. There were significantly more problems described by Vietnamese parents as compared with Cambodian parents. Vietnamese parents reported significantly more dissatisfaction with life in the United States. For both ethnic groups, parents' relationships with their adolescent children were a major source of concern and had a major impact on parents' perceptions of their own health. Yet, there were important ethnic differences between these refugee groups in how patients perceived their problems.

Acculturation↗
PubMed1994

Scintigraphic findings of osteomyelitis after intraosseous infusion in a child.

A case of unilateral tibial osteomyelitis in a 20-month-old child after bilateral intraosseous infusion (IOI) needle placement is presented. A review of the indications, potential complications, and scan findings is discussed. This case also shows the lack of significant uptake in the noninfected side, suggesting that a three-phase bone scan is of value in differentiating reactive bone from infected bone in patients with IOI.

Female↗
PubMed1994

Scintigraphic manifestations of "sternal cupping".

Sternal abnormalities in sickle-cell disease have been documented by bone scintigraphy and radiography in patients with homozygous sickle-cell anemia, but not in patients with sickle-thalassemia. We present here two unusual cases of sternal abnormalities in complicated sickle-cell disease. One is an infant with radiographic findings of "sternal cupping" and transient hypo-ossification of the sternum and sickle-thalassemia. The other patient is also a male infant with unusual, persistent under-ossification of bone, in association with radiographic findings of "sternal cupping." The second patient also had a 4P-chromosomal defect (Wolf-Hirschhorn syndrome) in which sternal hypo-ossification was described.

Abnormalities, Multiple↗
PubMed1993

Should hypertension be treated after acute stroke? A randomized controlled trial using single photon emission computed tomography.

OBJECTIVE: To determine if previously hypertensive patients with acute ischemic stroke should be treated with antihypertensive medication in the immediate poststroke period. DESIGN: Randomized double-blind, placebo-controlled trial. SETTING: Sixteen consecutive hypertensive patients (four men and 12 women; mean age, 66 years [age range, 46 to 83 years]) with middle cerebral artery infarction within 72 hours of onset and blood pressure between 170 and 220 mm Hg(systolic) and 95 and 120 mm Hg (diastolic). INTERVENTION: Placebo (n = 6), nicardipine hydrochloride (20 mg [n = 5]), captopril (12.5 mg [n = 3]), or clonidine hydrochloride (0.1 mg [n = 2]) given every 8 hours for 3 days. MAIN OUTCOME MEASURES: Decline in blood pressure, change in cerebral blood flow as measured by single photon emission computed tomography, and clinical change as determined by the National Institutes of Health Stroke Scale. RESULTS: Blood pressure fell significantly in both the drug-treated group as a whole and in those patients receiving placebo (P < .001). There was no difference in blood pressure levels between these two groups throughout the study period. Patients receiving nicardipine had a consistently lower pressure than the other groups. A significant negative relationship was noted between the maximum blood pressure fall and improvement in cerebral blood flow. There were four patients whose blood pressure dropped by more than 16% of the baseline value on any 24 hours in the first 3 days. All either failed to increase or actually decreased their cerebral blood flow to the affected area. Three of these patients were treated with nicardipine. There was no significant difference in clinical course between the placebo-and drug-treated groups as a whole. CONCLUSIONS: Hypertensive ischemic stroke patients with a moderate elevation of blood pressure in the first few days may not require antihypertensive therapy. Nicardipine and possibly other calcium channel blockers may cause an excessive fall in blood pressure and impair cerebral blood flow in these patients and should therefore be used with caution.

Aged↗
PubMed1993

Value of single-photon emission-computed tomography in acute stroke therapeutic trials.

BACKGROUND AND PURPOSE: New therapeutic interventions for acute ischemic stroke are aimed at improving cerebral blood flow in the first 3 to 6 hours after symptom onset. Single-photon emission-computed tomography (SPECT) performed in the setting of clinical therapeutic trials may give us a better understanding of the physiological response to new forms of treatment and could impact acute management decisions. METHODS: We prospectively studied 15 patients with hemispheric ischemic stroke with SPECT within 6 hours of symptom onset and again at 24 hours. The ischemic defect was assessed in a semiquantitative manner that used computer-generated regions of interest (SPECT graded scale). This measure was correlated with clinical presentation (National Institutes of Health [NIH] Stroke Scale), initial clinical course (change in NIH Stroke Scale), long-term outcome (Barthel Index at 3 months), and complications of cerebral hemorrhage and edema. RESULTS: The severity of the SPECT graded scale on the admission scan correlated with the severity of neurological deficit (admission NIH Stroke Scale) (P < .05) and was positively associated with poor long-term outcome as measured with the Barthel Index (P < .001) and the complications of cerebral hemorrhage and massive cerebral edema (P < .005). In fact, there was a threshold value for the SPECT graded scale above which all patients suffered poor long-term outcome and the complications of cerebral hemorrhage and edema. CONCLUSIONS: The measurement of an ischemic defect using SPECT is a valid assessment of hemispheric stroke severity in the hyperacute setting and may be useful for selecting or stratifying patients in clinical therapeutic trials.

Acute Disease↗
PubMed1991

Delayed visualization of the gallbladder with a rim sign. An unusual finding in chronic cholecystitis.

The rim sign of increased activity in the gallbladder fossa during nuclear hepatobiliary imaging has been described, with one exception, only in conjunction with a nonvisualizing gallbladder, and it strongly suggests acute complicated cholecystitis. A case is presented in which a rim sign was present despite later visualization of the gallbladder in presumed chronic cholecystitis.

Adult↗