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Biomedical subjects

P J Li

Publications and source records attributed to P J Li.

14 recordsLinked to original sources
PubMed2005

DNA changes in barley (Hordeum vulgare) seedlings induced by cadmium pollution using RAPD analysis.

In recent years, several plant species have been used as bioindicators, and several tests have been developed to evaluate the toxicity of environmental contaminants on vegetal organisms. In this study, barley (Hordeum vulgare L) seedling was used as bioindicator of cadmium (Cd) pollution in the range of 30-120 mgl(-1). Inhibition of root growth and reduction of total soluble protein content in root tips of barley seedlings were observed with the increase of Cd concentrations. The changes occurring in random amplified polymorphic DNA (RAPD) profiles of root tips following Cd treatment included variation in band intensity, loss of normal bands and appearance of new bands compared with the normal seedlings. Additionally, we found that the effect of changes was dose-dependent. These results indicated that genomic template stability (a qualitative measure reflecting changes in RAPD profiles) was significantly affected at the above Cd concentration. Thus, DNA polymorphisms detected by RAPD analysis could be used as an investigation tool for environmental toxicology and as a useful biomarker assay for the detection of genotoxic effects of Cd pollution on plants.

Biomarkers↗
PubMed2001

Epstein-Barr virus (EBV) in Chinese pediatric Hodgkin disease: Hodgkin disease in young children is an EBV-related lymphoma.

BACKGROUND: The Epstein-Barr virus (EBV) is thought to be involved in the pathogenesis of some Hodgkin disease (HD) cases. EBV may be associated particularly with childhood HD, a disease rare in the West compared with developing countries. In this study, a large series of Chinese pediatric HD cases has been examined to determine the age-specific prevalence of EBV. METHODS: Paraffin sections from 104 pediatric and 52 adult Chinese HD cases were examined for EBV-RNA (EBERs) and EBV latent membrane protein-1. RESULTS: Most pediatric cases arose in boys and showed an histology of mixed cellularity. Prominent interfollicular involvement was seen frequently in the childhood cases. EBV was identified in tumor cells in 113 of 156 (72%) HD cases but was more frequent in pediatric cases (93 of 104; 89%) compared with adult cases (20 of 52; 38%) (P < 0.01; chi-square test). EBV was found in 86 out of 91 (95%) cases in children aged 3-10 years and in 7 out of 13 (54%) cases in children aged 11-14 years (P < 0.01; chi-square test). The virus was less frequent in cases in young adults than in old adults, although this trend was not significant (P > 0.05; chi-square test). Pediatric HD was associated with EBV irrespective of histologic subtype. In adults, EBV was associated more frequently with mixed cellularity than with other subtypes. CONCLUSION: To the authors' knowledge, this is to date the largest series of pediatric HD cases studied for EBV. Study findings provided further evidence that HD is etiologically heterogeneous. The authors believe that pediatric HD now should be regarded as a distinctive EBV-related lymphoma.

Adolescent↗
PubMed2000

Transfer of lead via placenta and breast milk in human.

The mean lead levels in the maternal blood, cord blood, breast milk and placental tissue, were 0.63 mumol/L (13.2 micrograms/dL), 0.33 mumol/L (6.90 micrograms/dL), 4.74 micrograms/L and 0.86 mumol/kg (17.85 micrograms/100 g) respectively for 165 parturient women occupationally non-exposed to lead in 2 hospitals in Shanghai. No significant difference was found between maternal age groups for these indicators. However, the lead levels in the cord blood and breast milk increased with the lead level in the maternal blood, with coefficient of correlation of 0.714 (P < 0.0001) and 0.353 (P < 0.01) respectively. The mean concentration of lead in breast milk for 12 occupationally lead exposed women was 52.7 micrograms/L, which was almost 12 times higher than that for the occupationally non-exposed population. These results suggested that transfer of lead via placenta prenatally and breast milk postnatally were possible and might pose a potential health hazard to the fetuses and the neonates.

Adult↗
PubMed1996

The distribution of HgCl2 in rat body and its effects on fetus.

Both female and male Wistar rats were dividend into 3 groups according to their body weights. The two test groups were given 75 micrograms/ml and 7.5 micrograms/ml HgCl, respectively, via drinking water, while the control group was given distilled water. Animals were mated after the male rats were treated for 12 weeks and female rats for 2 weeks. Blood samples from rats were taken on the 18th day of the pregnancy and the results showed that the HgCl2 was absorbed and stored in the blood in the form of inorganic mercury. The greatest amount of HgCl2 was found in the kidney. The placenta and the tests also had high mercury deposits. Fetuses showed low levels of HgCl2, thus, the placenta appears to serve as a barrier against HgCl2. No pathological changes were observed in the placenta, ovary, liver, and kidney in the female rats, but the epithelial cells of the rental proximal convoluted tubules were cloudy and swelling. The renal corpuscle showed no changes in the male rats. Pathological examination showed that a portion of the seminiferous epithelia were falling off, and the number of sperm released by the male was reduced. Examination by electron microscopy revealed that particulate fat was increased in sperm cells, which suggests that spermatozoa had been degenerated and were possibly one of the causes for the decreased rates of pregnancy in the exposed groups. No malformation of organs and bones in the rat fetuses were observed.

Animals↗
PubMed1994

[The association of Epstein-Barr virus with Hodgkin's lymphoma in childhood].

Specimens from 82 children with Hodgkin's lymphoma were studied by immunohistochemical technique for Epstein-Barr virus encoded latent membrane protein (LMP). LMP was demonstrated in 67 cases 81.7%, the positive rate for the mixed cellular subtype was 90.9%. The positive rate for the 3-5 year old group of patients was 100%, 75% for the 6-10 year old group and only 62.5% for the 11-14 year old group. These findings suggest that Epstein-Barr virus is strongly associated with Hodgkin's lymphoma, the younger the age, the stronger the association. Mixed cellular subtype of Hodgkin's lymphoma had the strongest association with Epstein-Barr virus among all subtypes.

Adolescent↗
PubMed1992

[Pulmonary blastoma: a light-microscopic, immunohistochemical and electron-microscopic study of six cases in childhood].

Pulmonary blastoma is a very rare primary tumor of the lung, which mostly occur at a late age in adults. Six cases in children under four years of age are reported in this series. The light-microscopic, immunohistochemical and electron-microscopic characteristics revealed that the elements of P.B. in childhood consist mainly of mesenchymal components, including undifferentiated large cells and small round cells, which tend to differentiate toward rhabdomyosarcoma. The epithelial components comprise only a small portion of the total tumor, and most appear as the well-demarcate branching tubular structures lined with columnar or cubiodal epithelium merging with the stroma. The degree of differentiation of mesenchymal elements is closely related to the prognosis.

Child, Preschool↗
PubMed1991

[Malignant histiocytosis: a study on clinicopathological features and cell origin].

Thirty-one autopsy cases previously diagnosed as malignant histiocytosis (MH) were studied by means of immunohistochemical staining. Antibodies detecting the formalin resistant epitopes on T-cells, B-cells and those of histiocyte/monocyte origin were used. It was shown that the malignant histiocytes reacted only to the cell markers derived from histiocyte/monocyte, and only a part of lymphocytes showed positive reaction to the T and B cell markers. It is suggested that the histiocyte/monocyte lineage is the possible origin of the malignant proliferating cells in MH. The clinicopathological features and the differentiation of MH from familial erythrophagocytic lymphohistiocytosis, virus-associated hemophagocytic syndrome and malignant lymphoma are described. The pathogenesis, the causes of death and the points for attention in the treatment of MH are also discussed.

Child↗
PubMed1987

Integrated state of subgenomic fragments of hepatitis B virus DNA in hepatocellular carcinoma from mainland China.

Hepatocellular carcinoma (HCC) samples from mainland China were examined for the presence and state of hepatitis B virus (HBV) DNA sequences. HBV DNA was detected by dot-blot hybridization in 13 of 17 cases of HCC from the Shanghai area and in three of six samples from Hangzhou. The HCC cases from Shanghai were then analyzed in more detail. Fifteen of the 17 patients had serologic evidence of past or present infection with HBV (with inadequate information available for the other two), and the 13 HCC samples positive for HBV DNA all came from serologically positive patients. Southern blot analysis showed that the HBV DNA sequences were always integrated in the HCC high-molecular-weight DNA; only one or two viral copies were present per tumor cell, and no common integration site was evident. Hybridization analyses using subgenomic probes of HBV DNA revealed that the tumors seldom retained an entire HBV genome. HBV S-region sequences were always present, X-region sequences were usually represented, and C-region sequences were rarely detectable in virus-positive tumors. A fragment within the HBV DNA X-region, between nucleotides 1441 and 1526, was found to hybridize nonspecifically with cellular DNA; reported sequence data indicated that this fragment would contain approximately 70% guanine + cytosine. Histologic sections were prepared from some of the frozen tissue specimens and stained by an indirect immunoperoxidase technique for hepatitis B surface antigen (HBsAg). Only 1 of 10 HBV DNA-positive samples contained HBsAg in the cytoplasm of tumor cells, although abundant HBsAg was present in adjacent normal cells in all 10 cases. There were no significant differences in histology between HCC that contained HBV DNA sequences and those that were virus negative. These data support the premise that HBV represents a major etiologic factor in the development of HCC in the Shanghai area of China, although the molecular basis of viral involvement remains obscure.

Adult↗
PubMed1986

L&H variants of Reed-Sternberg cells express sialylated Leu M1 antigen.

Anti-Leu M1 generally does not stain the lymphocytic and histiocytic (L&H) variants of Reed-Sternberg cells in the lymphocyte predominant type of Hodgkin's disease. However, the authors found that after neuraminidase treatment for removal of sialic acid, the L&H cells in more than half of the cases studied could be stained by anti-Leu M1. This result strongly suggests that L&H cells differ from the Reed-Sternberg cells in other types of Hodgkin's disease in their unique capacity to sialylate the 150-kd Leu M1 antigen.

Antigens↗
PubMedDate not supplied

Pertussis toxin-sensitive G-proteins and regulation of blood pressure in the spontaneously hypertensive rat.

1. Increased Gi-protein-mediated receptor-effector coupling in the vasculature of the spontaneously hypertensive rat (SHR) has been proposed as a contributing factor in the maintenance of elevated blood pressure. If increased Gi-protein-mediated activity plays an important role in hypertension in SHR, then inhibition of Gi-proteins by pertussis toxin would be expected to decrease blood pressure in this genetic hypertensive model. To address this hypothesis, studies were undertaken comparing the cardiovascular effects of pertussis toxin in SHR and normotensive Wistar-Kyoto (WKY) rats. 2. Spontaneously hypertensive and WKY rats were instrumented with radiotelemetry devices and blood pressure measurements were recorded in conscious rats. Following a single injection of pertussis toxin (10 micrograms/kg, i.v.), mean arterial blood pressure fell from 161 +/- 3 to 146 +/- 1 mmHg in the SHR and the effect was sustained for more than 2 weeks. In contrast, 10 micrograms/kg, i.v., pertussis toxin produced no significant effect on blood pressure in WKY rats (103 +/- 4 vs 101 +/- 5 mmHg). 3. In a separate study, SHR and WKY rats were administered 30 micrograms/kg, i.v., pertussis toxin or 150 microL/kg, i.v., saline and, 3-5 days later, rats were anaesthetized and instrumented to permit measurement of blood pressure and renal function. At this higher dose, pertussis toxin reduced blood pressure in both strains of rat, although the effect was markedly greater in SHR (approximately 40 mmHg decrease) compared with WKY rats (approximately 15 mmHg decrease). In SHR, pertussis toxin increased renal blood flow (from 5.7 +/- 0.3 to 7.5 +/- 0.8 mL/min per g kidney) and decreased renal vascular resistance (from 31 +/- 2 to 19 +/- 2 mmHg/mL per min per g kidney). In WKY rats, pertussis toxin had no significant effect on renal parameters. 4. Results from these studies indicate that a pertussis toxin-sensitive Gi-protein-mediated pathway contributes to the maintenance of hypertension and elevated renal vascular tone in the SHR.

Animals↗
PubMedDate not supplied

[Blood exchange transfusion as an emergency treatment for hyperleukocytosis in leukemia: report of one case].

An extreme leukocytosis imposes immediate and potential catastrophic problems, which warrant the use of intensive means to reduce the excessive leukocytes. Blood exchange transfusion has been used for emergency management of hyperleukocytosis. With few complications the procedure can rapidly reduce an excessive leukocyte burden, correct concomitant anemia and improve associated metabolic abnormalities. The greatest advantage of this procedure is that it can be performed in the shortest time, with minimal equipment and technical skill. This is a report of an 11-month-old male patient with acute lymphoblastic leukemia who had hyperleukocytosis, then received emergency blood exchange which reduced the leukocyte count from 630,000/ul to 70,000/ul in two hours. The course was smooth and the patient tolerated the procedure well. Remission was attained after the induction and consolidation chemotherapy, and the child is now under maintenance therapy.

Acute Disease↗