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Biomedical subjects

S N Cheng

Publications and source records attributed to S N Cheng.

14 recordsLinked to original sources

Improved treatment results for childhood acute myeloid leukemia in Taiwan.

To improve treatment results for children with de novo acute myeloid leukemia (AML), we introduced a novel protocol, Taiwan Pediatric Oncology Group-AML-97A, for AML other than acute promyelocytic leukemia (APL), for which modified conventional protocols were used. From January 1, 1997, to December 31, 2002, 141 children younger than 17 years old with de novo AML were enrolled. In total, 117 patients with non-APL AML were treated with induction therapy of idarubicin and cytarabine (Ara-C), postremission therapy with high-dose Ara-C - containing regimens for four monthly courses, and moderate-dose therapy with idarubicin and Ara-C for four monthly courses. The first 19 patients with APL were treated with all-trans retinoic acid, idarubicin and Ara-C, with the remaining five patients receiving all-trans retinoic acid and idarubicin, followed by maintenance therapy for 2 years. Stem cell transplantation was performed in 29 patients in first remission with a similar outcome as chemotherapy alone. The remission rate in the AML-97A study was 90%, the 5-year survival 51 +/- 5.3% (s.e.) and the 5-year event-free survival 50 +/- 4.8%; for APL, these were 100%, 86 +/- 7.0, and 75 +/- 9.8%. For the whole group, the 5-year survival was 57 +/- 4.7% and the 5-year event-free survival 54 +/- 4.4%. The AML-97A regimen was well tolerated.

Adolescent↗

Perinatal cytomegalovirus infection complicated with pneumonitis and adrenalitis in a premature infant.

Cytomegalovirus causes pneumonia, hepatitis, thrombocytopenia, and hemolytic anemia. Cytomegalovirus adrenalitis in premature infants, however, is rare. This report described a premature newborn who had progressively worsening hyperbilirubinemia, pancytopenia, and hepatosplenomegaly at the age of 4 days. The baby's mother had prolonged rupture of amniotic membrane for about 8 weeks. The infant received exchange blood transfusion, empiric antibiotics treatment, and mechanical ventilation. Pneumonia and sepsis developed at the age of 18 days. Serum anticytomegalovirus immunoglobulin M and urine virus culture were positive for cytomegalovirus. The baby died at the age of 22 days. Autopsy showed cytomegalovirus infection complicated with interstitial pneumonitis and pulmonary edema, subacute bronchopulmonary dysplasia with interstitial fibrosis, and adrenalitis. We concluded that the functional status of the adrenal glands in cytomegalovirus-infected premature newborns who have unexplained electrolytes imbalance, fever, diarrhea, weight loss, or hypotension should be closely followed because of the possible involvement of adrenal glands.

Adrenal Gland Diseases↗

Cytotoxic factors released by dengue virus-infected human blood monocytes.

Human monocyte-derived cytotoxic factors (CF) induced by dengue virus were studied. Using several human leukemia cell lines as precursors, the biological activities of CF in conditioned medium from dengue virus-infected monocytes were demonstrated through the measurement of tumor cell growth inhibition. The conditioned medium from dengue virus infected monocytes suppressed significantly growth of CEM, HL60, K562, and U937 cells. In the presence of 10% conditioned medium (v/v) from dengue virus infected monocytes, DNA synthesis of U937 cells, as measured by [3H]thymidine incorporation, decreased by 99% in contrast to their synthesis in conditioned medium from noninfected control monocytes, which did not have any suppressive effect. Partial characterization of CF showed that it is a proteinase-K-sensitive and heat-labile protein with a molecular mass over 100 kDa. Employing a flow cytometric analysis of the cell cycle, it was found that U937 cells, treated either with conditioned medium from dengue virus infected monocytes or with CF, but not treated with conditioned medium from noninfected monocytes, showed cell-cycle arrest in G1 phase by 48 hr. This suppressive effect of CF on U937 growth was dose- and time-dependent. These results suggest that dengue virus-infected monocytes may produce CF to target myeloid cells, resulting in the hematological changes observed in patients with dengue fever.

Adult↗

Automated segmentation of regions of interest on hand radiographs.

Most radiologists do not use texture information contained in the trabecular patterns of hand radiographs to diagnose erosive changes and demineralization due to systemic inflammatory diseases that affect the skeletal system. However, high-resolution digitization achievable by a laser digitizer now makes it possible to access texture information that may not be perceived visually. We are studying the feasibility of computer-assisted early detection of these processes with particular attention to patients with hyperparathyroidism. In this paper the methods used to extract a region of interest (ROI) for texture analysis are discussed. The techniques include multiresolution sensing, automatic adaptive thresholding, detection of orientation angle, and projection taken perpendicular to the line of least second moment. The methods were tested on a database of 50 pairs of hand radiographs. We segmented the middle and the index fingers with an average success rate of 83% per hand. For the segmented finger strips, we located ROIs on both the middle and the proximal phalanges correctly over 84% of the times. Texture information was collected in the form of a concurrence matrix within the ROI. This study is a prelude to evaluating the correlation between classification based on texture analysis and diagnosis made by experienced radiologists.

Automation↗

Induction of interleukin-8 expression in neuroblastoma cells by retinoic acid: implication of leukocyte chemotaxis and activation.

Neuroblastoma cells in response to retinoic acid (RA) exhibit differentiation. RA, which can promote tumor cell differentiation, has also been shown to regulate tumor-infiltrating leukocytes. In an attempt to explore the relationship between RA-induced neuroblastoma cell differentiation and leukocyte chemotaxis, we investigated expression of IL-1 beta, IL-8, granulocyte-macrophage colony stimulating factor, and tumor necrosis factor-alpha in the undifferentiated and RA-induced differentiated neuroblastoma cells. Using SK-N-SH neuroblastoma cells, we found that RA induced differentiation of SK-N-SH cells as demonstrated by down-regulation of N-myc gene expression, cell-cycle arrest in G1 phase, and phenotypic change. Neither RA-treated nor untreated neuroblastoma cells expressed IL-1 beta, granulocyte-macrophage colony stimulating factor, or tumor necrosis factor-alpha mRNA. RA-treated but not untreated SK-N-SH cells expressed IL-8 mRNA in a time- and dose-dependent fashion. As determined by ELISA, IL-8 levels were detectable in the culture supernatants from RA-treated, but not untreated, neuroblastoma cells (2.65 +/- 0.43 versus 0.05 +/- 0.04 ng/mL). Using neutrophil and lymphocyte chemotactic assays, we found that RA-treated but not untreated culture supernatants of neuroblastoma cells promoted neutrophil and lymphocyte chemotaxis. The RA enhancement of neuroblastoma cell-mediated leukocyte chemotaxis was significantly blocked by anti-IL-8 neutralizing antibodies. These results suggest that RA-induced neuroblastoma cell differentiation is associated with production of functional IL-8, which may be involved in the leukocyte infiltration and activation resulting in tumor regression.

Cell Differentiation↗

Effect of picibanil (OK432) on neutrophil-mediated antitumor activity: implication of monocyte-derived neutrophil-activating factors.

Picibanil (OK432), an extract from streptococci, has been widely utilized to treat malignant ascites and pleural effusions. The antitumor mechanism is believed to include complement-mediated neutrophil activation. Employing a flow-cytometric analysis of actin polymerization as an indicator of cell activation as well as a tumor proliferation assay, we have found that monocyte-derived neutrophil-activating factors were involved in OK432-induced neutrophil activation as well as antitumor activity. OK432-stimulated (0.1 KE/ml; 0.01 mg/ml) monocyte supernatants (OKMS) induced neutrophil actin polymerization and chemotaxis. OKMS were responsible for neutrophil-mediated inhibition of human leukemic (CEM) cell proliferation and stimulated neutrophils to produce superoxide in the presence of CEM leukemic cells at an effector/target ratio higher than 20/1. In contrast, OK432 alone, OK432-stimulated lymphocyte supernatants, or OK432-stimulated neutrophil supernatants had no effect on neutrophil activation or suppression of tumor cell proliferation. OK432 in combination with mononuclear cells also had no effect on the inhibition of CEM cell proliferation. Pretreatment of OKMS at 56 degrees C for 30 min did not affect its ability to activate neutrophils, implying that complement activation is not responsible for the neutrophil activation. Supernatants from OK432-stimulated mononuclear cells, as determined by enzyme-linked immunosorbent assays and radioimmunoassays, contained high levels of interleukin-8 (IL-8; 1567 +/- 145 pg/ml) and tumor necrosis factor (TNF alpha; 2105 +/- 152 pg/ml), low levels of leukotriene B4 (800 +/- 45 pg/ml) and IL-1 beta (180 +/- 22 pg/ml), but interferon gamma was not detectable. IL-1 beta, IL-8, and TNF alpha transcripts, undetectable in untreated monocytes, increased significantly after 30-60 min exposure to OK432. These results suggest that neutrophil-activating factors from monocytes or resident macrophages may play an important role in the OK432-induced neutrophil activation and antitumor activity.

Adult↗

Leukocyte adhesion deficiency disorder: report of one case.

In this paper, a case of leukocyte adhesion deficiency disorder confirmed by flow cytometry and leukocyte chemotaxis assays is reported. The 32-day-old female infant was admitted to our ward on account of delayed umbilical cord detachment and omphalitis. After admission, hemogram revealed severe leukocytosis (white blood cell (WBC) counts: 86,800/cumm), and there was poor clinical response to several kinds of antibiotics. The above history indicated that the patient might be a case of leukocyte adhesion deficiency disorder. A definite absence of CD11b/CD18 adhesion molecule on the patient's granulocytes and severe defects of leukocyte function demonstrated by chemotaxis, chemokinesis and zymosan-induced respiratory burst assays confirmed this diagnosis.

Bone Marrow Transplantation↗

Xanthoma of bone in a normolipidemic child: report of one case.

Xanthoma invasion of the bone is a very rare disease especially in normolipidemic children. Bone erosion can be found in patients with this disease. However, due to the similarity of the symptoms of xanthoma with many other diseases including malignancy, the other diseases may initially be to be suggested and xanthoma may not even be considered. In this paper, we present an 8-year-old normolipidemic male child with a parietal bone xanthoma proved using tissue diagnosis. The clinical, radiographic and histological findings are also reviewed.

Child↗

Treatment results of the TPOG-NHL92 protocols for childhood non-Hodgkin's lymphomas in Taiwan: a report from the Taiwan Pediatric Oncology Group (TPOG)

A nation-wide chemotherapeutic trial for childhood non-Hodgkin's lymphoma (NHL) was conducted by the Taiwan Pediatric Oncology Group (TPOG). Four TPOG-NHL92 protocols based on stage and histology were activated in 1992: TPOG-92LD (treatment duration: 8 months) was used for localized (stages I/II) NHL with any histology, 92LB (2 years), 92SNC (5 months), and 92LC (1 year) for advanced (stages III/IV) lymphoblastic (LB), small non-cleaved cell (SNC), and large cell (LC) lymphoma, respectively. From January 1992 through June 1998, 200 children with newly diagnosed NHL from 13 member hospitals of TPOG were enrolled. There were 140 boys and 60 girls. Their ages at diagnosis ranged from 2.4 months to 18.3 years with a median of 8.2 years. There were 54 (27.3%) patients with LB, 94 (47.5%) with SNC including B-cell acute lymphoblastic leukemia (B-ALL), and 50 (25.2%) with LC. Stages I, II, III, and IV (including B-ALL) of the disease comprised 5%, 10%, 43%, and 42% of cases, respectively. There were 176 patients eligible for evaluation of treatment results. The remission rate of induction was 82.4%, induction failed in 22 (12.5%) patients, and nine patients died during induction. As of August 31, 1999, 26 patients relapsed, six died during remission, one patient developed secondary acute myelomonocytic leukemia, and 105 patients remained in continuous remission with a median remission duration of 49 months. The event-free survival (EFS) at 7 years was 63.5%, 61.5% and 65% for LB, SNC, and LC groups (P = 0.8298). The 7-year EFS for stages I/II, III, and IV of the disease was 73%, 68.9%, and 50.3% (P = 0.0212), respectively. We concluded that following the strategy of stratification of therapy, only disease stages had prognostic significance in this study. More efforts are needed to improve our treatment results.

Adolescent↗

Subglottic hemangioma associated with cutaneous and cerebellar hemangiomas detected by MRI: report of one case.

Subglottic hemangioma (SGH) is a benign neoplasm that may cause severe and life-threatening respiratory obstruction in infants. However, patients usually present with inspiratory stridor in the first few months of life and may be mistakenly diagnosed as recurrent or persistent croup. Definitive diagnosis is made by image studies, endoscopic examination and biopsy or all. We report a 2-month-old female infant of SGH with initial clinical manifestations of dyspnea and inspiratory stridor co-existing with cutaneous and cerebellar hemangiomas. Clinicians must be alert the possibility of SGH when associated with cutaneous hemangioma. This patient has received oral steroid treatment for more than two months with improvement of the airway obstruction. Although purplish patch lesions over left side of face, eyelid, cheek, and peri-oral regions regressed, the size of the SGH on the followed MRI was slightly enlarged. The diagnosis and various treatments of SGH are discussed and reviewed in this paper.

Adrenal Cortex Hormones↗

Intracranial malignant rhabdoid tumor: report of one case.

A 4-year-old boy presented with anorexia, headache, and poor spirits was found to have tumors in posterior fossa and suprasellar region which enclosed by CT scan of brain. Bilateral suboccipital craniotomy was performed by neurosurgeon. The pathological report revealed the tumor was malignant rhabdoid tumor. The patient died two and one half months after diagnosis in spite of surgical resection and radiotherapy of the tumor.

Brain Neoplasms↗

Trichosporon beigelii causing oral mucositis and fungemia: report of one case.

A 23-month-old boy, a victim of acute myelomonocytic leukemia (AML), was admitted for chemotherapy. On the eighth hospital day, he started a one-week course of chemotherapy with agents of epirubicin and cytosine arabinoside. Unfortunately, persistent neutropenia, deteriorating diarrhea and intermittently spiking fever developed from the sixteenth hospital day. Initially, ceftazidime and amikacin were empirically utilized. Blood culture yielded Klebsiella pneumoniae and the fever subsided for one day. Unfortunately, oral mucositis and catheter-induced phlebitis developed subsequently. Subsequently, oral nystatin and intravenous oxacillin were added. The results of cultures from both blood and oral mucosal tissue yielded a fungus. Trichosporon beigelii. We changed from an oral antifungal agent to intravenous amphotericin B on the twenty-fourth hospital day. He presented signs of septic shock with disseminated intravascular coagulopathy and expired on the twenty-fifth hospital day after failure to respond to aggressive resuscitation. We report this case to emphasize that in cytotoxic chemotherapy-induced granulocytopenic AML patients who have compromised immune systems, and who may manifest some signs or symptoms of infection, and at the same time poorly respond to interventional antibiotic treatment, the possibility of T. beigelii infection can not be neglected.

Fungemia↗