Biomedical subjects

C Dang

Publications and source records attributed to C Dang.

26 records · Page 2Linked to original sources

PubMed1996

Oligonucleotide inhibitors of Taq DNA polymerase facilitate detection of low copy number targets by PCR.

A random sequence library of single stranded DNA was screened to isolate sequences with high affinity for Thermus aquaticus DNA polymerase (Taq pol), a thermostable enzyme commonly used in the polymerase chain reaction (PCR). Selected oligonucleotide sequences bound Taq pol with dissociation constants in the low picomolar range, and efficiently inhibited polymerase activity at room temperature (20 to 25 degrees C), but did not inhibit at temperatures above 40 degrees C. Moreover, inhibition was thermally reversible. A process called "hot start" PCR is commonly used to prevent non-specific PCR products in amplification of low copy number targets. We show that the addition of oligonucleotide inhibitors eliminated the need for "hot start" conditions and improved the efficiency of detection of a low copy number target in PCR.

DNA, Viral↗

PubMed1995

DNA enzyme immunoassay of the PCR-amplified HLA-DQ alpha gene for estimating residual leukocytes in filtered blood.

Blood is filtered for selective removal of leukocytes (WBC) to reduce the immunological and virological risks of transfusion. Exceedingly low numbers of residual WBC in leukodepleted blood cannot be enumerated by conventional hematologic methods. Therefore, we investigated the application of a DNA enzyme immunoassay (DEIA) for detecting a region of the HLA-DQ alpha gene following amplification by PCR. After hybridization with a specific probe coated onto the wells of a microtiter plate, the PCR-amplified DNA was detected by adding monoclonal antibodies to double-stranded DNA, enzyme tracer, and chromogen substrate for colorimetric measurement. The sensitivities of DEIA and radioisotopic liquid hybridization were similar in five sets of experiments performed with a known number of human WBC. The optical density and the number of spiked human WBC in the range of 1.0 to 0.05 cells per microliter showed good correlation in five calibration experiments performed with human WBC suspended in heterologous blood. Using a calibration curve for DEIA, we estimated the concentration of residual WBC in five individual units of erythrocytes passed through blood filters. The postfiltration WBC count was 1.6 WBC per microliter in one unit, while in four other units it was below the lower detection limit (< 0.05 WBC per microliter) of the DEIA. DEIA obviates the use of radioisotopes in PCR for detection of exceedingly low numbers of residual WBC in filtered blood.

Animals↗

PubMed1993

The Glasgow Coma Scale and prognosis in gunshot wounds to the brain.

To determine which factors predict survival in patients with gunshot wounds to the brain, 192 patients who had intracranial injury demonstrated on computed tomographic (CT) scanning were retrospectively reviewed. Glasgow Coma Scale (GCS) scores on admission seemed to be the most important factor in predicting survival. Age, the presence of extruded brain, and use of a shotgun could not be shown to be factors independent of admission GCS score. Findings on CT scans (single lobe vs. multilobe involvement) helped to predict survival only in patients with GCS scores 5-13. The mortality rate was 35%. Among survivors 18% had brain-related long-term disability, and an additional 27% had long-term disability related to associated eye injury.

Adolescent↗

PubMed1990

Delayed rupture of the spleen.

The concept of delayed splenic rupture is an evolving one. The cases reviewed have led us to reserve the term "delayed splenic rupture" for the situation in which early post-traumatic imaging of the spleen is normal and is followed by the diagnosis of splenic hemorrhage 48 or more hours after the initial insult. Post-traumatic splenic evaluation is indicated when the mechanism of injury is likely to injure the spleen, there is unexplained hypovolemia, or the patient complains of left upper quadrant pain or tenderness. Peritoneal lavage is indicated when hypovolemia is the main manifestation. Radionuclide study is used for screening isolated splenic or hepatic injury when the suspicion is low. Reduced availability of visceral angiogram has resulted in CT scan becoming the main diagnostic modality. When a patient presents with blunt abdominal trauma, awareness of the problem of splenic rupture and active diagnostic approach may help reduce the morbidity and mortality associated with splenic hemorrhage, either immediate or delayed.

Emergencies↗

PubMed1989

Emergency department thoracotomy.

The best candidates for a community hospital emergency room thoracotomy are those victims who have decompensated following small-caliber gunshot wounds or stab wounds to the chest or abdomen who initially had signs of life in transport to the hospital or in the Emergency Department. Some of these patients can be successfully resuscitated by an emergency physician using the techniques described in this article.

Acquired Immunodeficiency Syndrome↗

PubMed1985

Management of aortoesophageal fistula. A case report.

A case of aortoesophageal fistula, secondary to a false aneurysm of the thoracic aorta is presented. Esophagoscopy and aortography are high-yield diagnostic procedures. The Sengstaken-Blakemore tube provides a satisfactory temporizing measure. Definitive repair should include aortic replacement with a Dacron graft through clean tissue planes.

Aortic Diseases↗

PubMed1981

Generalized arteriomegaly. A possible predisposition to the formation of abdominal aortic aneurysms.

Studies of patients with arteriomegaly have suggested that an increased incidence of aneurysms occurs in patients with unusually large arteries. However, as far as we know, a study of comparative arterial sites in consecutive patients with aneurysms has not been reported previously. We have compared the diameters of the suprarenal abdominal aortas and iliac arteries in concurrent consecutive series of 12 male patients with aneurysms and 12 male patients with atherosclerotic occlusive disease. These vessels remote from the aneurysms were 40% to 48% larger in diameter in the aneurysmal group by both angiography and direct measurement. In addition, the patients with aneurysms were found to be taller and to have a greater mean body surface area. Possible implications of these findings relevant to the pathogenesis of aneurysms are suggested.

Aorta, Abdominal↗

PubMed1975

Traumatic arterio-ureteral fistula: "hematuria" without urine.

A case is presented in which a patient with a gunshot wound in the abdomen sustained a traumatic arterio-ureteral fistula with resultant continual output of bloody fluid from the urethral catheter in the absence of any real production of urine. It is important to recognize the possibility of false reassurance regarding the patient's general status by supposing fluid thus produced to be an indication of actual urine formation.

Adult↗