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Biomedical subjects

D C Liang

Publications and source records attributed to D C Liang.

At least 91 records · Page 5Linked to original sources
PubMed1984

The growth of single crystals of (L-arginine)B0 bovine insulin and their preliminary X-ray crystallographic analysis.

The crystals of (L-Arg)B0 bovine insulin large enough for X-ray structure analysis have been grown by vapour diffusion in a buffer containing citrate, acetone and zinc chloride. The X-ray diffraction of the crystals extends to 3.0 A spacing. The crystals belong to the trigonal system with unit cell dimension of a = b = 81.82 A, c = 35.05 A, alpha = beta = 90 degrees, gamma = 120 degrees, space group R3. There are two insulin molecules in the crystallographic asymmetric unit.

Animals↗
PubMed1983

Subcellular site of antispermatogenic effect of gossypol and its possible molecular mechanism of action.

This paper reports the results of gossypol effects on the testicular mitochondrial ultrastructures and functions. A hypothesis of mechanism of gossypol action based on our experimental data was postulated. Electron microscopic observations confirmed further our previous studies that the mitochondria of the target germ cells were the most sensitive and the most severely damaged among cellular organelles in response to gossypol. The damages included the swelling, vacuolation, crista depletion, lysis, granular accumulation in matrix and the process of intact mitochondria disintegration. The activity of the mitochondrial marker enzyme, the LDH-X of human spermatozoa, was markedly decreased or suppressed completely after gossypol treatment. The functions of isolated testicular mitochondria determined by Warburg manometric and oxygen electrode polarographic methods indicated that gossypol stimulated respiration but inhibited slightly the oxidative phosphorylation at low concentrations (20-40 microM) in vitro. With the increase in concentration of gossypol, the mitochondrial respiration and phosphorylation decreased obviously, they were completely inhibited at a concentration of 80 microM for oxidative phosphorylation and at about 300 microM for respiration. The degree of uncoupling of phosphorylation appears to be dose-dependent. Similar results were obtained for the testicular mitochondria isolated from rats that had been administered per os gossypol previously (6 mg, 10 mg and 15 mg/day X 21 respectively), in which the P/0 ratio decreased significantly (P less than 0.001) as compared with that of the control group. The distribution of 14C-gossypol in mitochondrial was found to be 2-3 times higher than that in other subcellular fractions. Similar pattern of distribution was shown in double labeling experiments with 14C-gossypol and 3H-ouabain.

Animals↗
PubMedDate not supplied

Effects of thrombopoietin on megakaryocyte colony formation from leukemic cells at diagnosis and from marrow cells after induction chemotherapy for acute leukemias.

We have studied the effects of recombinant human thrombopoietin (TPO, mpl ligand) on the megakaryocyte colony formation from control human bone marrow cells, human leukemia cells at diagnosis, and human bone marrow cells after induction chemotherapy for acute leukemias. In the control human bone marrow cells from four adults and nine children who had localized malignancy and histologically normal-looking marrow. TPO alone effectively stimulated megakaryocyte colony formation, and interleukin-3 (IL-3) synergized this. In 17 patients (13 adults and four children) with acute myeloid leukemia (AML) at diagnosis, TPO stimulated leukemic colony formation in only one patient with FAB M7 subtype. In 11 children with acute lymphoblastic leukemia (ALL) at diagnosis, TPO did not enhance leukemic colony formation. After 17 courses of induction chemotherapy, nine for AML and eight for ALL, TPO stimulated megakaryocyte colony formation to a level of 51%, of that in the control human bone marrow cells. This may suggest that the administration of TPO to patients with M7 subtype warrants caution, whereas it is probably safe to give TPO at any time to patients with ALL. The administration of TPO to patients with acute leukemias after induction chemotherapy could stimulate megakaryocytopoiesis.

Acute Disease↗
PubMedDate not supplied

Imerslund-Gräsbeck syndrome in two brothers: renal biopsy and ultrastructural findings.

In two Chinese siblings with Imerslund-Gräsbeck syndrome, light microscopy of renal biopsies showed no remarkable change. Ultrastructurally, there were small possible focal defects in the glomerular basement membrane. Neither podocytes nor tubular cells showed evident change. No electron dense deposit was found. Our observations on renal ultrastructure differ from the previous five reports. The literature on renal pathology of this syndrome is reviewed.

Anemia, Megaloblastic↗
PubMedDate not supplied

Varicella vaccine in children with acute lymphoblastic leukemia and non-Hodgkin lymphoma.

To determine the safety and efficacy of varicella vaccine, 17 children with acute lymphoblastic leukemia (ALL) and 2 children with non-Hodgkin lymphoma (NHL) receiving chemotherapy in remission were immunized with live attenuated varicella vaccine (Oka strain). Rash occurred in 7 children 7-53 days (median 24 days) after vaccination. There were 10-80 (median 20) erythematous vesicles and low-grade fever. All children required no specific treatment. There was no spread of varicella to their susceptible siblings. The control group comprised 92 ALL and 25 NHL patients receiving chemotherapy in remission who were nonvaccinated and susceptible to varicella. Over a risk duration of 80 person-years, one child of the vaccinated group developed varicella of mild degree, whereas in a risk duration of 120 person-years, 14 of the control group developed varicella. One patient died, though prompt antiviral therapy, especially acyclovir, was given to all of them. Herpes zoster of mild degree was observed in one child of the vaccinated group 65 days after vaccination. Two children of the control group developed disseminated herpes zoster. With acyclovir therapy, there was no mortality. The incidence of varicella in the vaccinated group was less than that of the control group. The difference is statistically significant (p = .0222), and the side effects of the vaccine were acceptable. Thus we conclude that the vaccine can be safely used in children with ALL or NHL under chemotherapy and can effectively protect such children from varicella.

Chickenpox↗
PubMedDate not supplied

Intravenous immunoglobulin prophylaxis in children with acute leukemia following exposure to varicella.

The high risk of varicella in immunocompromised children has been well documented. With the aim of diminishing this risk, attempts have been made to modify or prevent varicella by passive immunization. From September 1985 to March 1991, five children with leukemia, having a total of seven episodes of intimate exposure to varicella, received a single dose (200 mg/kg) of intravenous immunoglobulin (IVIG) within 3 days of exposure. The patients included four children with acute lymphoblastic leukemia and one child with myelodysplastic syndrome in acute myeloblastic leukemic transformation. None of the five children developed varicella following IVIG infusion. No side effects were observed. IVIG appears to be an effective and safe alternative for preventing varicella in immunocompromised patients upon intimate exposure, when zoster immunoglobulin or varicella-zoster immunoglobulin is unavailable, as in Taiwan.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Granulopoiesis in newly diagnosed childhood solid tumors.

Granulopoiesis at the diagnosis of solid tumors has not been previously reported. The purpose of this study is to detect the changes of granulopoiesis of patients with solid tumors in different clinical stages. Granulocyte-macrophage colony-forming unit (CFU-GM) assays and liquid suspension cultures of bone marrow and peripheral blood were studied in 90 children with newly diagnosed solid tumors, including 5 benign tumors and 85 malignant tumors. The malignant tumors were categorized into nonadvanced, advanced, or marrow-invaded ones. Bone marrow from children with immune thrombocytopenic purpura and peripheral blood from adult volunteers were used as controls. Granulocyte-macrophage colony formation from bone marrow in benign or nonadvanced malignant tumor was not significantly different from that of controls. However, granulocyte macrophage colony formation from bone marrow in advanced or marrow-invaded malignant tumor was significantly less than that of controls or nonadvanced malignant tumor. Furthermore, the bone marrow of patients with advanced malignant tumor occasionally had a defective proliferation pattern and the bone marrow of those with marrow-invaded malignant tumor often had a defective proliferation pattern. Peripheral blood in marrow-invaded malignant tumor had colony and cluster formations in very wide ranges. As a malignant tumor progresses into advanced stages, irrespective of marrow infiltration, bone marrow CFU-GM levels may decline and defective granulopoiesis may occur.

Adolescent↗
PubMedDate not supplied

The stage I yolk sac tumor of testis in children younger than 2 years, chemotherapy or not?

Yolk sac tumor is the most frequent germ cell tumor of testis in children. For stage I yolk sac tumor of testis in children younger than 2 years, high inguinal orchiectomy alone has been the standard treatment, with a cure rate of at least 75%. Here, we compare the treatment results of receiving chemotherapy or no chemotherapy after orchiectomy, to analyze the role of chemotherapy. From February 1987 to January 1997, 22 children younger than 2 years, with stage I yolk sac tumor of testis, were included in the study. All patients had high inguinal orchiectomy without retroperitoneal lymphadenectomy. Initial diagnostic imaging studies included computed tomographic scan of abdomen, chest radiography, and long bone survey. Clinical stage I was defined as a tumor completely resected with no evidence of local regional lymph node involvement or distant metastases. Serum alpha-fetoprotein (AFP) was assessed at diagnosis. After orchiectomy, diagnosis, and staging, patients were stratified into two treatment groups, with or without chemotherapy, according to the decision of the parents. Ten children received chemotherapy consisting of cisplatin, vinblastine, and bleomycin (PVB, modified "Einhorn regimen") for 12 weeks. The remaining 12 patients were followed up according to a "wait and see" policy. Determination of AFP was performed monthly during the first postoperative year, every other month during the second year, every 3 months during the third year, every 6 months during the fourth year, and yearly until the fifth postoperative year at least. The duration of follow-up ranged from 3 months to 119 months (median, 53 months). The Kaplan-Meier plot estimated an overall survival rate of 91.6% at 7 years after diagnosis. Among the 12 patients without chemotherapy, 2 children had relapses at 4 and 6 months after diagnosis, respectively. One was cured with PVB chemotherapy. The other patient died with refractory lung metastasis, in spite of intensive multimodality salvage therapy. The Kaplan-Meier plot showed a survival rate of 80% at 7 years and a relapse-free survival rate of 81.8% at 5 years after diagnosis. All children receiving chemotherapy were alive and free from relapse. There was no significant treatment-related toxicity. Our results may suggest that PVB chemotherapy after orchiectomy is an affective and safe regimen for stage I yolk sac tumor of testis in children younger than 2 years. Instead of four courses of PVB as used here, two or three courses could be enough. To elucidate the necessity for chemotherapy and to determine the number of courses of PVB needed (if chemotherapy is given), a randomized study of more cases is warranted.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Pancreatic tumors in children: report of three cases.

From 1981 to 1996, we experienced 3 cases of pancreatic tumors in children--two pancreatoblastomas (PB) and one solid and cystic tumor (SCT). The ages were 1 month, 4 years, and 13 years of age respectively. The two cases of pancreatoblastoma initially presented as chronic diarrhea with failure to thrive, the other case presented with abdominal mass. All of them were studied by laboratory examination, ultrasonography, computed tomography and pathology. Increasing alpha- fetoprotein (AFP) levels were found in the 2 pancreatoblastoma cases, however, the level in the SCT case was normal. Abdominal sonography showed pancreatic masses with or without calcification, and the echogenicity may be solid and/or cystic. All patients underwent total excision of the tumors. We have reviewed the literature and find no pancreatoblastoma with chronic diarrhea was reported in young children, especially in neonate. Therefore, we suggest that young children presenting with an abdominal mass and/or weight loss should undergo imaging studies for the possibility of pancreatic tumors.

Adolescent↗
PubMedDate not supplied

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↗
PubMedDate not supplied

Treatment of testicular relapse in childhood acute lymphoblastic leukemia.

The experience of rescue therapy for 6 patients of childhood acute lymphoblastic leukemia (ALL) with testicular relapse is reported. In two patients, testicular relapse occurred 1 and 4 years off therapy, respectively. Two patients had testicular relapse on therapy. The remaining 2 patients had testicular relapse after premature discontinuation of therapy by the parents. Isolated testicular relapse was found in 2 patients. The rest of the testicular relapses were concurrent with either bone marrow (BM) or central nervous system (CNS) relapses. The rescue therapy included bilateral testicular irradiation 24 Gy, and systemic reinduction chemotherapy, followed by maintenance therapy as that of TCL 821 or TCL 842 protocol for high risk patients of ALL. CNS prophylaxis, which included intrathecal medication and/or cranial irradiation 18 Gy (if not given before), was also given. After testicular relapse, one had subsequent BM and CNS relapses and received more aggressive chemotherapy. Another one had subsequent CNS relapse 4 months after another premature withdrawal of treatment. One patient, who presented with CNS leukemia at diagnosis, had concurrent testicular and CNS relapses and died of CNS leukemia 3 months later. The remaining 5 patients remained in continuous complete remission for 26 to 95 months with a median duration of 54 months.

Child↗
PubMedDate not supplied

Intracranial hemorrhage in the hemophiliacs.

Five of 34 hemophiliac children suffered from nine episodes of intracranial hemorrhage (ICH) from hemophilia A, and another 3 were B hemophiliacs. Diagnoses were confirmed by computed tomographic scan in all nine episodes. The ages of the patients with ICH ranged from 3 months to 4 1/2 years. The most frequent presenting symptoms were headache and vomiting, followed by focal neurological deficits. Eight of 9 episodes had bleeding in multiple regions. All the patients received immediate replacement therapy had recovered without surgical intervention. The duration of treatment was 10 +/- 2 days. All the patients survived and only one of them had neurological sequela as left hand paresis. From this observation we suggest that the treatment of suspected ICH in hemophiliacs should include prompt replacement therapy for either trauma or neurological symptoms in the absence of trauma history, documentation of ICH by computed tomographic scan, and prolonged replacement therapy and control of increased intracranial pressure in hemophiliacs with documented ICH.

Cerebral Hemorrhage↗