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Biomedical subjects

M R Park

Publications and source records attributed to M R Park.

At least 19 recordsLinked to original sources
PubMed2001

Tissue specific and inducible expression of resveratrol synthase gene in peanut plants.

The expression of resveratrol synthase (RS) genes is induced by biotic and abiotic factors in peanut cell cultures. However, little is known about the regulation of the RS gene expression in peanut plants. The expression of RS genes was investigated in peanut plants with a peanut RS clone, pPRS3C, which encodes two polypeptides that show about a 96% amino acid sequence identity to peanut RS2 and RS3, respectively. A low level of RS mRNA was detected in the roots of peanut plants grown aseptically in vitro. In mature peanut plants that were grown in the field, however, RS mRNAs were present at relatively high levels in both the roots and pods, but at below the detection limit in leaves. RS mRNAs were abundant in young pods and decreased dramatically in mature pods. The RS mRNA expression was induced by yeast extract and UV in leaves and roots, and also by wounding in leaves. Stress hormones, such as ethylene, jasmonic acid, and salicylic acid, induced RS mRNA accumulation in leaves. These results indicate that the RS gene expression is induced by biotic and abiotic stresses through the stress hormones in peanut plants. The induction of the RS gene expression by biotic and abiotic stresses could provide peanut plants with protection from microbial infections through resveratrol synthesis. The RS gene expression in developing pods has significant implications in terms of the role of resveratrol as a phytochemical for human health.

Acyltransferases↗
PubMed2001

Increased angiogenesis and Fas-ligand expression are independent processes in acute myeloid leukemia.

We evaluated the clinical significance of tumor angiogenesis and Fas-ligand (FasL) expression using parameters including the microvessel count (MVC), vascular endothelial growth factor (VEGF) level, and FasL expression in patients with acute myeloid leukemia (AML). Paraffin-embedded bone marrow (BM) sections from 43 AML patients at diagnosis, 20 patients after subsequent induction therapy, and 18 controls with non-invasive lymphoma were stained immunohistochemically for von Willebrand factor (vWF) and FasL. VEGF in BM mononuclear cells from 32 AML patients at diagnosis and 10 controls, including bone marrow transplantation donors, was assayed by an ELISA method. We found that the mean MVC, VEGF level, and FasL expression in AML patients at diagnosis were significantly higher than those of controls, with a significant correlation between the MVC and VEGF levels (r=0.43). However, there were no correlations between FasL expression and MVC or VEGF level. The mean MVC and FasL expression after induction therapy were lower than those evaluated at diagnosis, but were higher than those of controls. There was a correlation between the MVC and percentage of BM blasts (r=0.479), but no correlation between the MVC, VEGF level, or FasL expression and other hematologic or clinical variables. Our findings provide evidence of increased angiogenesis and tumor immune escape in AML, and both angiogenesis and tumor immune escape are independent processes in AML.

Adolescent↗
PubMed2001

Clinical efficacy of granulocyte transfusion therapy in patients with neutropenia-related infections.

Granulocyte transfusions have been advocated by some for the treatment of severe, progressive infections in neutropenic patients who fail to respond to antimicrobial agents and recombinant hematopoietic growth factors. We conducted the current study to determine an appropriate method of granulocyte mobilization in healthy donors, and to evaluate the safety and efficacy of granulocyte transfusion therapy in patients with neutropenia-related infections. To mobilize granulocytes (n=55), healthy normal donors were stimulated in one of the following ways: (1) dexamethasone, 3 mg/m2 intravenously 15 min prior to leukapheresis (n = 5); (2) granulocyte colony-stimulating factor (G-CSF), 5 microg/kg subcutaneously 12 to 14 h prior to collection (n=37); or (3) G-CSF and dexamethasone (n= 13). The mean granulocyte yield from stimulation with G-CSF plus dexamethasone was significantly higher than from stimulation with dexamethasone or G-CSF alone. Twenty-five patients with severe neutropenia-related infections unresponsive to appropriate antimicrobial agents received a total of 55 granulocyte transfusions. The patients from whom fungi or Gram-negative organisms were isolated showed a more favorable response than those infected with Gram-positive organisms. However, the responses to the granulocyte transfusion therapy could not be correlated with the transfused dose, mobilization agents, or the 1 h or 24 h post-transfusion absolute neutrophil counts. We conclude that granulocyte transfusion therapy may be clinically useful for neutropenia-related infections by fungi or Gram-negative organisms.

Adolescent↗
PubMed2001

Telomere length changes in patients with aplastic anaemia.

To investigate telomere changes in patients with aplastic anaemia (AA) and clinical factors influencing the telomere dynamics, telomere length (TL) was measured in peripheral blood mononuclear cells using Southern blot analysis of 42 patients with AA and 39 healthy normal controls. Nineteen patients received supportive treatment only, while the remaining 23 patients received immunosuppressive therapy with anti-thymocyte globulin or anti-lymphocyte globulin +/- cyclosporin A. In AA patients, TL was on average 1.41 kb shorter than that of age-matched normal controls (P < 0.001). In patients treated with immunosuppression, the mean TL of non-responders was significantly shorter than that of age-matched normal controls (P < 0.001), while no difference in TL was detected in responders compared with controls. Positive correlation was observed between the extent of telomere shortening, the severity of neutropenia (P = 0.05) and the degree of mean corpuscular volume elevation (P = 0.005) at the time of the study. However, there was no correlation with time elapsed since diagnosis (P = 0.214). These findings suggest that haematopoietic stem cells in patients with AA rapidly lose TL at the onset of the disease. The TL shortening may reflect the severity of impairment of haematopoiesis.

Adolescent↗
PubMed2001

Secondary myeloid/natural killer cell acute leukemia following T-cell lymphoma.

A 56-year-old woman was treated with combination chemotherapy and radiation therapy for peripheral T-cell lymphoma. Following complete remission for a period of 6 months, she returned again with marked leukocytosis. Leukemic cells were characterized by scanty cytoplasm with fine azurophilic granules, and were highly positive for myeloperoxidase and sudan black-B. Immunophenotypic analysis revealed that blast cells were positive for myeloid antigens (CD13, CD33), and natural killer (NK) cell antigen (CD56), but negative for T-cell antigens (CD2, CD5, CD7), B-cell antigens (CD19, CD20), CD34, and HLA-DR. The case was diagnosed as secondary myeloid/NK cell acute leukemia following non-Hodgkin's lymphoma. Despite aggressive chemotherapy against leukemia, she died of multiorgan failure 7 months following onset of leukemia. We present, to the best of our knowledge, the first published report of what seems to be a secondary myeloid/NK cell acute leukemia following T-cell lymphoma.

Acute Disease↗
PubMed2000

Ruptured Klebsiella pneumoniae liver abscess after high-dose cyclophosphamide for severe aplastic anemia.

A 19-year-old woman with severe aplastic anemia who had previously failed antithymocyte globulin/cyclosporine A received high-dose cyclophosphamide without bone marrow rescue. On day +14, she complained of right upper quadrant abdominal pain and fever. A CT scan of the abdomen showed multiple liver abscesses with rupture and Klebsiella pneumoniae was isolated from blood. In spite of aggressive antibiotic therapy, she rapidly deteriorated and died of overwhelming sepsis. To our knowledge, our patient is the first case of fatal ruptured liver abscess after high-dose cyclophosphamide in a patient with severe aplastic anemia.

Adult↗
PubMed2000

A randomized comparison of oral and intravaginal misoprostol for labor induction.

OBJECTIVE: To compare oral misoprostol (100 microgram) to vaginal misoprostol (25 microgram) for cervical ripening and labor induction. METHODS: Two hundred thirty-six women with medical or obstetric indications for labor induction and undilated, uneffaced cervices were assigned randomly to receive 100 microgram of oral or 25 microgram of vaginal misoprostol every 4 hours for 24 hours. Intravenous oxytocin was then given using a standardized protocol. We anticipated that 31% of women treated orally and 50% of women treated vaginally would deliver vaginally within 24 hours of starting labor induction. RESULTS: Among 234 subjects, 121 received oral and 113 received vaginal misoprostol. The mean (+/- standard deviation [SD]) interval from start of induction to delivery was 1240 +/- 845 minutes for orally treated women and 1381 +/- 802 minutes for vaginally treated women (P =.06, log-transformed data). More orally treated women delivered vaginally in 24 hours than vaginally treated women (74 versus 54, P =.14, relative risk [RR] 1.14, 95% confidence interval [CI] 0.92, 1.40). One hundred six women (87.6%) who received oral misoprostol delivered vaginally, compared with 88 women (77.9%) who received vaginal misoprostol (P =.07). Oxytocin was given to 60 (49. 6%) orally treated and 59 (52.2%) vaginally treated subjects (P =. 69). More women in the oral group had tachysystole, nine compared with two (P =.06), hypertonus, and hyperstimulation. Frequencies of intrapartum complications and birth outcomes were similar between groups. CONCLUSION: Oral misoprostol 100 microgram and vaginal misoprostol 25 microgram were similarly effective for cervical ripening and labor induction. Oral administration was associated with trends toward higher likelihood of vaginal delivery and more uterine tachysystole.

Administration, Intravaginal↗
PubMed2000

Acquired hemophilia successfully treated with oral immunosuppressive therapy.

Acquired hemophilia is a rare disorder associated with serious bleeding in nonhemophilic patients. We had a 40-year-old woman who was diagnosed as acquired hemophilia with a factor VIII inhibitor level of 27.5 BU/mL. She was presented with gross hematuria and severe right shoulder pain, and was successfully treated with daily oral cyclophosphamide and prednisone for 2 weeks. After the remission, the doses of prednisone and cyclophosphamide were slowly decreased and she remained in complete remission without further bleeding episodes.

Administration, Oral↗
PubMed1999

Portal, mesenteric, and splenic vein thromboses after splenectomy in a patient with chronic myeloid leukemia variant with thrombocythemic onset.

Portal, mesenteric, or splenic vein thrombosis is a very uncommon complication with significant mortality in the patients undergoing splenectomy for hematologic disorders. We report a 49-year-old woman who developed portal, superior mesenteric, and splenic vein thromboses after splenectomy. Four years before the event, she presented with a marked thrombocytosis and was diagnosed to have chronic myeloid leukemia variant with thrombocythemic onset as evidence by Philadelphia (Ph1) chromosome and a b3a2 BCR/ABL transcript. Six weeks after splenectomy, she developed severe epigastric pain. The diagnosis of thromboses of portal, mesenteric, and splenic veins was made by computed tomography scan and Doppler sonogram. She was successfully treated with antegrade intraarterial urokinase therapy via superior mesenteric artery and long-term anticoagulant therapies. To our knowledge, our patient is the first case of portal, mesenteric, and splenic vein thromboses after splenectomy in a patient with CML variant with thrombocythemic onset successfully treated with antegrade intraarterial thrombolytic therapy followed by anticoagulant therapies.

Female↗
PubMed1999

Hepatosplenic B-cell lymphoma associated with hemophagocytic syndrome: a case report.

While T-cell non-Hodgkin's lymphoma (NHL) associated with hemophagocytic syndrome (HPS) has been frequently observed, B-cell NHL associated with HPS has been rarely reported. We report a case of hepatosplenic B-cell lymphoma associated with HPS in a 41-year-old woman who presented with fever of unknown origin. An abdominal CT scan revealed splenomegaly with focal splenic infarction. Splenectomy and a liver wedge biopsy showed sinusoidal-pattern infiltration of medium to large tumor cells with positive reaction to a B-lymphocyte marker. Findings on bone marrow examination showed proliferation of histiocytes with avid hemophagocytosis.

Adult↗
PubMed1998

Prophylaxis for deep vein thrombosis with aspirin or low molecular weight dextran in Korean patients undergoing total hip replacement. A randomized controlled trial.

150 Korean patients undergoing primary uncemented total hip replacement were randomized into 3 treatment groups for deep vein thrombosis (DVT) prophylaxis. Group A(50) were controls; Group B(50) received aspirin 1.2 g daily in 3 divided doses from 2 days before, to 14 days after surgery; Group C(50), received low molecular weight dextran 500 ml, infused intravenously at 50 ml/hour during surgery, and on each of the following 2 days. Contrast venograms were performed prior to surgery and 7-10 days after. The incidence of DVT was 20% in the control group, 12% in the aspirin group (p < 0.1 vs control), and 6% in the dextran group (p < 0.05 vs control). In patients developing DVT, the ratio of proximal to distal thrombi was increased in the control group as compared to treated groups (4:1 in the control group vs 1.5:1 in the treated groups). Both aspirin and dextran were well tolerated. Obesity (p < 0.05) and long-term administration of steroids (p < 0.05) were risk factors for deep vein thrombosis which reached statistical significance in the control group. Intraoperative venograms performed on 10 patients, showed that hip flexion (mean 40.4 degrees) plus adduction (mean 11.5 degrees) plus internal rotation (mean 81.5 degrees), resulted in severe twisting or kinking of the femoral vein with stagnation of blood flow. Low molecular weight dextran significantly reduce the incidence of deep venous thrombosis and aspirin, though less effective, had a similar effect.

Adult↗
PubMed1998

Acute hemolytic crisis with fulminant hepatic failure as the first manifestation of Wilson's disease: a case report.

We report a 27-year-old woman who developed Coombs' negative hemolytic anemia and fulminant hepatic failure as the initial manifestation of Wilson's disease. Unmeasurably low level of serum alkaline phosphatase provided a clue to the diagnosis of Wilson's disease. The diagnosis was established with the presence of Kayser-Fleischer ring, decreased serum ceruloplasmin level, and elevated urine and serum copper levels. In spite of repeated plasmapheresis, she died of multiorgan failure on the fifth hospital day.

Acute Disease↗
PubMed1998

A case of chronic graft-versus-host-disease following allogeneic peripheral blood stem cell rescue for poor graft function after bone marrow transplantation.

To overcome poor graft function after allogeneic bone marrow transplantation (BMT), the use of peripheral blood stem cells (PBSC) instead of bone marrow is gaining more popularity because of its advantages. There may, however, be an increased risk of graft-versus-host-disease (GVHD) because of the large number of lymphocytes present in a leukapheresis product. An 18-year-old man with severe aplastic anemia underwent an allogeneic BMT using his HLA-identical sister. After initial excellent graft take for 8 months, his blood counts gradually decreased to 2.8 x 10(9)/L of white cells and 28 x 10(9)/L of platelets with marrow cellularity of < 10%. After allogeneic granulocyte-colony stimulating factor mobilized PBSC rescue, the patient's blood counts recovered satisfactorily. Around 1 year after the boost, he developed chronic GVHD that responded to prednisolone and cyclosporin A. He is now well on low-dose steroids at day +1055 after PBSC rescue. The present case is the first experience of a long-term follow-up who underwent allogeneic PBSC rescue in Korea.

Adolescent↗
PubMed1998

A case of Marfan syndrome with acute monoblastic leukemia.

We report on an 18-year-old man who had both acute monoblastic leukemia and Marfan syndrome. A diagnosis of Marfan syndrome was established by those characteristics of arachnodactyly, ectopia lentis, mitral valve prolapse, and mitral regurgitation. Findings on bone marrow examination of the patient showed that most of nucleated cells were monoblasts and immunophenotype of those cells showed CD13+, CD33+, CD56+, and HLA-DR+. To our knowledge, this is the second report of leukemia in Marfan syndrome in the world.

Adolescent↗
PubMed1997

Deep vein thrombosis after uncemented total hip replacement.

One-hundred-fourteen consecutive cases of venography after primary uncemented total hip replacement were performed in a randomized trial to identify the natural incidence of deep vein thrombosis, the effectiveness of prophylactic regimens such as 1.2 grams of aspirin daily and low-molecular-weight dextran for 3 days, and other relative factors for the development of venous thrombosis. In addition, intraoperative venography was conducted in 10 patients to study the speed of the flow of contrast media in the femoral vein and the development of deep vein thrombosis and the extent of the twisting of the femoral vein during hip joint manipulation. The incidence of venous thrombosis in the control, aspirin, and dextran prophylaxis groups were 20%, 11.5%, and 5.2% respectively. The incidence in the aspirin group was reduced, but this was statistically insignificant. The dextran group showed a marked decrease in incidence, and the difference with the control group was statistically significant. With regard to the development site of venous thrombosis, it was prevalent in iliofemoral, lower femoral, and major calf vein in the control group, while the popliteal and major calf vein were the major site of thrombosis development in the aspirin and dextran groups. The risk factors affecting the incidence of the venous thrombosis are confirmed to be obesity and long-term administration of steroids. Hematologic analysis was meaningless in investigating the development of venous thrombosis. The reliable clinical sign and symptom suggestive of the development of venous thrombosis was the severe swelling on the entire portion of affected lower extremity. In the intraoperative venogram, no correlation was found between the venous blood flow speed and the development of venous thrombi. A remarkable change in the blood flow of the femoral vein was noticed when the hip joint was flexed an average of 40.4 degrees, adducted at 11.5 degrees, and internally rotated at 81.5 degrees. Especially, when the joint was internally rotated, severe kinking of the vein could be observed. Thus it seems desirable to reduce the duration of internal rotation of the hip joint as much as possible to prevent venous thrombosis.

Adult↗
PubMed1997

A new suggestion for the treatment of minimally displaced fractures of the greater tuberosity of the proximal humerus.

Fourteen shoulders in 14 patients with minimally displaced fractures of the greater tuberosity of the proximal humerus were evaluated, at an average of 3 years, 7 months (range: 1 year to 6 years, 1 month) after the operation. For comparison this portion of the proximal humerus was measured using 100 Korean adult cadaveric humeri. The results of these preliminary studies suggest that the patients presenting with a one-part fracture of the greater tuberosity of the proximal humerus should be evaluated individually. In most patients in whom the displacement of the fragment is less than 5 mm, good results can be obtained with non-operative treatment. If the displacement of the fragment is more than 5 mm in young active patients, and more than 3 mm in individuals (especially athletes and heavy laborers) involved in overhead activity, the fragment should be mobilized, repaired, and fixed into its original bed or slightly inferolaterally.

Adult↗
PubMed1993

Ubiquitin marks the reactive swellings of diffuse axonal injury.

Ubiquitin is a protein that targets proteins for non-lysosomal degradation. It has been found to be present in a number of inclusions characteristic of neurodegenerative diseases. Using the fluid percussion model of closed head injury in the cat, a well-established model of diffuse axonal injury (DAI), we now report that the reactive axonal swellings and the retraction balls produced in this model stain positively with anti-ubiquitin immunohistochemistry. Furthermore, the affected axons become ubiquitin positive quickly (within the first 6 h after injury). Anti-ubiquitin immunohistochemistry compares well with the recently reported ability of antibodies to low molecular weight neurofilament proteins to demonstrate reactive axonal change in DAI, and it could provide additional clues to the pathogenesis of axonal transection.

Animals↗