Biomedical subjects

H Y Chu

Publications and source records attributed to H Y Chu.

At least 19 recordsLinked to original sources

PubMed2006

Phytotoxicity of lanthanum in rice in haplic acrisols and cambisols.

Growth and physiological responses of rice to lanthanum were studied to elucidate the function of lanthanum in plants and its critical concentration relative to environmental safety. Shoot La content increased with the increasing added La concentrations. When shoot La content exceeded a toxic value, plant growth and chlorophyll a/b decreased and peroxidase (POD) activity, cell membrane permeability, and content of proline in the leaf increased. Leaf chlorophyll a/b and POD activity might provide useful criteria for early diagnoses of phytotoxicity of soil contaminated by La. In the present study, the critical concentration of La for rice relative to environmental safety was suggested to be 42.03 mg kg(-1) in red soil and 83.33 mg kg(-1) in paddy soil.

Cell Membrane Permeability↗

PubMed2005

Sociodemographic and clinical characteristics of clients presenting for HIV voluntary counselling and testing in Moshi, Tanzania.

HIV voluntary counselling and testing (VCT) reduces high-risk sexual behaviour. Factors associated with HIV infection in VCT clients have not been well characterized in northern Tanzania. We prospectively surveyed 813 VCT clients in Moshi, Tanzania. Clients were administered a questionnaire on sociodemographic characteristics, sexual behaviour, and health status. Blood was taken for rapid HIV antibody testing. Factors associated with HIV seropositivity were identified using multivariate logistic regression analysis. Of 813 clients, the seroprevalence was 16.7%. The strongest associations with seropositivity were reporting diarrhoea (odds ratio [OR] 10.4, 95% confidence interval [CI] 3.6-29.9), an ill sexual partner (OR 6.3, 95% CI 3.0-12.9), or being a woman (OR 3.5, 95% CI 2.0-6.3). In a separate regression, the number of symptoms also predicted HIV infection (OR 2.1, 95% CI 1.6-2.6). VCT clients who tested positive had more HIV-related symptoms suggesting presentation at a later stage of HIV infection.

AIDS Serodiagnosis↗

PubMed1997

Primary intracranial germ-cell tumor in children.

BACKGROUND: Primary intracranial germ-cell tumors (GCTs) account for about 11.1% of all primary brain tumors of children in Taiwan. Because these tumors commonly involve the hypothalamus-pituitary gland regions and their biochemical secreting character, patients frequently display neuroendocrinological symptoms and signs. Endocrinopathy, if present, often occurs prior to other neurological or radiological manifestations. This article reviews experience here, with present results comparing them with previous reports. METHODS: Twelve children who were diagnosed with primary intracranial germ-cell tumors between 1983 to 1995 were studied retrospectively. Their clinical presentations, laboratory results and treatment modalities as well as the current status were collected for presentation here. RESULTS: There were seven boys and five girls. The age distribution was from 5 to 15 years old. The most common symptom was increased intracranial pressure (9/12), followed by diabetes insipidus (8/12), vision deficit (8/12) and sexual precocity in 3 boys. In 11 patients the tumors arose from the suprasellar or pineal regions. In two patients the tumors arose synchronously in the suprasellar and pineal regions. Pure germinoma was found in six patients. Only one had an elevated tumor marker. These six patients all received radiation with or without operation therapy, and all are still alive. Six patients, each with a non-germinomatous malignant germ-cell tumor, had a poorer prognosis. Although they received aggressive treatment, including operation, radiation and chemotherapy, three patients died, with a mean survival period of 3.3 years. CONCLUSIONS: In cases of diabetes insipidus in children or sexual precocity in boys, a thorough investigation for intracranial germ-cell tumors is recommended. The treatment and outcome are different for germinomas and non-germinomatous malignant germ-cell tumors. A thorough pathological diagnosis is recommended for planning of treatment protocol in order to improve prognosis.

Adolescent↗

PubMed1996

Hibiscus protocatechuic acid protects against oxidative damage induced by tert-butylhydroperoxide in rat primary hepatocytes.

Hibiscus protocatechuic acid (PCA), a simple phenolic compound isolated from Hibiscus sabdariffa L., was studied for its protective effects against oxidative damage induced by tert-butylhydroperoxide (t-BHP) in a primary culture of rat hepatocytes. It had been reported that exposure of isolated hepatocytes to t-BHP results in leakage of lactate dehydrogenase (LDH) and alanine transaminase (ALT), peroxidation of cellular lipids, and depolarization of mitochondria. The present investigations showed that PCA at concentrations of 0.05 mg/ml and 0.10 mg/ml significantly decreased the leakage of LDH (P < 0.01) and ALT (P < 0.05 and P < 0.01) and the formation of malondialdehyde (MDA; P < 0.05 and P < 0.01) induced by 30-min treatment with t-BHP (1.5 mM) in primary cultured rat hepatocytes. PCA also attenuated t-BHP (0.10 mM) induced mitochondrial depolarization as determined by a retention test of rhodamine 123 and DNA repair synthesis as evidenced by unscheduled DNA synthesis (UDS). In addition, PCA exhibited an effective ability to quench 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH). In conclusion, PCA demonstrated protective effects against cytotoxicity and genotoxicity of hepatocytes induced by t-BHP. One of mechanisms of PCA's protective effect may be associated with its property of scavenging free radicals.

Animals↗

PubMed1995

Effect of retinoic acid isomers on proliferation, differentiation and PML relocalization in the APL cell line NB4.

Retinoic acids exert a wide physiological role in development and differentiation. Retinoic acids have also been used in the treatment of human cancers, particularly in acute promyelocytic leukemia (APL). A structure-function relationship of the RA isomers in terms of clinical effect has been observed since all-trans retinoic acid (ATRA) induces a high complete remission rate while 13-cis retinoic acid (13-cis RA) shows much poorer effect. In this study, we examined the effect of RA isomers, including ATRA, 13-cis RA and 9-cis RA, on the proliferation and differentiation of NB4 cells. A number of parameters such as cell growth curve, dynamics of cell cycle, expression of clusters of differentiation and reduction of nitro blue tetrazolium (NBT) as well as immunofluorescence staining of PML were used to evaluate the effects of three isomers at two concentrations (10(-8) M and 10(-7) M). It has been shown that during the first 48 h of RA treatment, the APL cell differentiation was coupled with the cell proliferation. Although similar effects of proliferation inhibition and differentiation induction were observed among the three isomers at 10(-7) M, significant differences appeared at a concentration of 10(-8) M, 9-cis RA showed a higher activity than that of ATRA, while ATRA showed better results than 13-cis RA. Our results provide further evidence that 9-cis RA could be a promising molecule in differentiation induction of malignant cells.

Antigens, CD↗

PubMed1994

Varicella-zoster virus infection in children with malignancy.

BACKGROUND: Immunocompromised children are potentially threatened by infections, among which, the highly contagious chickenpox infection is the most common. In the past six months, there has been a spate of five chickenpox infections in children with malignancy, all of whom were receiving chemotherapy at that time. METHODS: The cases of 17 children with malignancies, who suffered from varicella-zoster infection during a period of chemotherapy at Taichung Veterans General Hospital were reviewed. RESULTS: The diagnoses of their neoplasms were 12 acute lymphoblastic leukemia (ALL), 2 lymphoma, 3 solid tumors. The mean age was 6.8 +/- 4.0 year-old (range 3 to 15 year-old). The average duration from chickenpox skin eruption to admission was 3.3 +/- 1.8 days. Four patients suffered from abdominal pain and three of them died soon; three of them suffered from back pain and one died later. Seven of these 11 patients had impaired liver function (GOT > 45 U/L), of whom 4 died later. There were seven patients with pneumonitis, of whom five died later. Among 12 patients with ALL, 3 had absolute lymphocyte counts (ALC) < 500/mm3, but only 1 died later; 9 had ALC > 500/mm3, of whom 4 had pneumonitis, and all died later. Four patients developed disseminated intravascular coagulopathy, and three of them died later. Seven patients were prescribed acyclovir within three days after first skin eruption, none of these died. Ten patients were prescribed acyclovir three days or more after first skin eruption and five of them died later. Five patients were prescribed intravenous immunoglobulin (IVIG) within three days after first skin eruption, and none of them died; of the seven patients prescribed IVIG three days or more after first skin eruption, three died later. CONCLUSIONS: Abdominal pain and disseminated intravascular coagulopathy (DIC) were signs of visceral dissemination. Severe liver function impairment, pneumonitis and DIC were the principal causes of death. Early administration of acyclovir and intravenous immunoglobulin (IVIG) can probably effectively prevent the dissemination of varicella-zoster virus (VZV). While varicella-zoster immunoglobulin (VZIG) was unavailable, IVIG was still valuable in treating VZV infection.

Acyclovir↗

PubMed1994

Leukemoid reaction in a child with appendiceal abscess: a case report.

A case of appendiceal abscess presenting leukemoid reaction is reported. A seven-month-old male infant was admitted because of fever and diarrhea. Anemic conjunctiva and mild abdominal distension were the only physical findings on arrival. Progressive leukocytosis with left shift maturation was noted during hospitalization. The maximal white blood cell count was 178,000/cumm, with a high leukocyte alkaline phosphatase score. On the fourth day of admission, a palpable right lower quadrant abdominal mass with local tenderness was found. Appendiceal abscess was diagnosed by both ultrasonography and computed tomography. The infant received triple antibiotic therapy consisting of ampicillin, gentamicin, and clindamycin for 10 days; the mass disappeared two weeks later. As appendiceal abscess is a rare occurrence in infants and its production of a leukemoid reaction is even rarer, the case described here may cause a diagnostic challenge, and deserves attention from clinicians.

Abscess↗

PubMed1993

Hyperglycemia induced by chemotherapeutic agents used in acute lymphoblastic leukemia: report of three cases.

Hyperglycemia may occur as a complication in patients with leukemia during induction therapy with L-asparaginase and steroids. The reported incidence is about 10%. The present report concerns three patients with acute lymphoblastic leukemia (ALL), complicated by hyperglycemia. Their ages were 10, 12, and 9 years, respectively. Past histories were normal, with no diabetes mellitus or other endocrine disorders in their families. Case 1 was an obese boy who developed pancreatitis and diabetic ketoacidosis (DKA) in his remission induction therapy which had included both L-asparaginase and steroids. Cases 2 and 3 both presented with polyuria and elevated postprandial blood sugar. For all patients, insulin was administered to control their blood sugars; the maximal daily dosage of insulin dispensed was 2.1 U/kg, 0.5 U/kg, and 0.7 U/kg, respectively. Increased plasma insulin and C-peptide levels suggestive of insulin resistance were observed in Case 3. The outcome of hyperglycemia in these three patients was good. The symptoms of this complication may vary from mild glucose intolerance to severe, or even fatal, DKA. Thus, periodic determinations of urine glucose and postprandial blood sugar are important for early recognition to prevent further life-threatening consequences.

Adrenal Cortex Hormones↗

PubMed1991

[Nemaline myopathy--a case report].

An 8-year-old Chinese girl who was noted to have feeding difficulty and poor weight gain since her infancy. Her motor development was delayed with sitting at 1-year-old and walking independently at 2-year-old. She visited our OPD when she was 8. Physically, she was thin and slender. Her height and weight were below the 10th and 3rd percentile. Her face was elongated with high arched palate. Neurologically, she had waddling gate with marked proximal muscle weakness. Her cranial nerves and sensation remained intact. Laboratory tests including blood routine, liver function, renal function, electrolytes, NCV and cardiac echo all were within normal limits. The EMG showed myopathic pattern. A fresh-frozen muscle biopsy stained with the modified Gomori trichrome, processed by histochemistry and electronmicroscopic examination showed typical nemaline rods with predominance of type 1 muscle fibers. She was then diagnosed to have nemaline myopathy.

Child↗

PubMed1989

[Childhood hypoplastic preleukemia].

Aplastic anemia preceeding acute leukemia is known as hypoplastic preleukemia, which tends to be more frequently evolved into acute lymphoblastic leukemia, whereas myelodysplastic preleukemia are specific for acute myelocytic leukemia. More than forty cases had been reported in the literatures. Here we report a 11-year-old boy who was initially diagnosed as aplastic anemia and treated with prednisolone and androgen with prompt response terminated into overt acute lymphoblastic leukemia.

Anemia, Aplastic↗

PubMed1988