Search PubMed⌕ Search

Biomedical subjects

W Ma

Publications and source records attributed to W Ma.

At least 91 records · Page 5Linked to original sources
PubMed2001

Immunohistochemical localization of Pax2 and associated proteins in the developing kidney of mice with renal hypoplasia.

Pax2 has been identified as a key regulatory protein associated with renal developmental malformations. The purpose of this study was to determine whether Pax2 protein expression, and that of other proteins important for normal renal development, is abnormally distributed in the prenatal kidney of the Brachyrrhine (Br) mouse that displays heritable renal hypoplasia. Embryonic 3H1 +/+ and Br/Br mice were collected between E11.0 and E18.0. Routine light microscopy and immunohistochemical analysis using antibodies to Pax2, E-cadherin, fibronectin, laminin, and Type IV collagen were applied to sequential tissue sections. E-cadherin stained consistently in the renal tubules of both normal and mutant animals. Whereas the initial expression of Pax2 corresponded between normal and mutant kidneys, it became progressively limited to the nephrogenic zone in +/+ animals, while distributing erratically in the Br/Br kidney. Fibronectin was not expressed in the normal nephrogenic zone but remained abundantly distributed throughout the Br/Br kidney. Luminin and Type IV collagen staining revealed a deficiency in renal vasculature formation in Br/Br kidneys. Results suggest that initial morphological differentiation occurs normally in the Br kidney but that subsequent nephric formation is associated with abnormal distribution of Pax2 and ECM proteins. (J Histochem Cytochem 49:1081-1097, 2001)

Animals↗
PubMed2001

Adult tissue angiogenesis: evidence for negative regulation by estrogen in the uterus.

Increased uterine vascular permeability and angiogenesis are two major events of embryo implantation and placentation during pregnancy. These latter processes require coordinated, uterine-specific interactions between progesterone (P4) and estrogen (E) signaling. Although roles of these steroids have long been suspected, definitive functions of E and/or P4 in uterine angiogenesis still remain elusive. We have therefore exploited the availability of reporter and mutant mice to explore the regulation of angiogenesis in response to steroid hormonal changes in vivo. We present here molecular, genetic, physiological, and pharmacological evidence that E and P4 have different effects in vivo: E promotes uterine vascular permeability but profoundly inhibits angiogenesis, whereas P4 stimulates angiogenesis with little effect on vascular permeability. These effects of E and P4 are mediated by differential spatiotemporal expression of proangiogenic factors in the uterus.

Animals↗
PubMed2001

Cadmium uptake by earthworms as related to the availability in the soil and the intestine.

The free metal concentration in the soil solution is often considered a key parameter for metal uptake by and toxicity to soft-bodied soil organisms. The equilibrium partitioning theory, which assumes a relationship between the contaminant concentration in pore water and the contaminant concentration in the body tissue, can be used to describe uptake by earthworms. This theory has proved useful for organic chemicals, but its applicability is less clear for metals. In this study, the Cd concentration in soil pore water (pw) was varied by increasing the soil pH by the addition of lime (Ca(OH)2) and by adding manganese oxide (MnO2), which has a high metal binding capacity. Both lime (0.135% w/w) and MnO2 (1% w/w) decreased [Cd2+]pw by a factor of 25, while Cdworm was reduced only by a factor of 1.3 in lime-treated soils and 2.5 in MnO2-treated soils. Cadmium uptake was weakly related to the free metal concentration (R2adj = 0.66). Adding pH as an explanatory variable increased R2adj to 0.89, indicating that Cd uptake from pore water is pH dependent, which might be attributed to competition of protons and Cd at the surface of the earthwororm body. However, previous earthworm experiments in reconstituted groundwater showed a conspicuously smaller pH dependency of Cd uptake. The differences in metal uptake between earthworms in lime- and MnO2-treated soils are therefore more likely to reflect the predominance of pH-independent intestinal uptake of Cd. Equilibrating the soil with a solution of 0.01 M CaCl2 and 0.1 M triethanolamine (buffered at pH 7.2), simulating the conditions prevailing in the worm intestine, yielded free Cd concentrations that were closely (R2adj = 0.83) and linearly related to the Cd concentration in the earthworm tissue.

Animals↗
PubMed2001

Chemiluminescence method with potassium permanganate for the determination of organic pollutants in seawater.

A chemiluminescence method with potassium permanganate was developed for use as an indicator of organic pollutants in fresh water. This method could be applied to the determination of organic pollutants in seawater as well. However, the flow chemiluminescence method suffered from the interference of chloride ions at the same concentration of seawater because of the production of manganese dioxide in the oxidation of chloride ions with permanganate. The conditions (concentrations of potassium permanganate and sulfuric acid and sample volume, i.e. flow injection method) were chosen to minimize the interference of chloride ions. The chemiluminescence method shows a good correlation with the chemical oxygen demand method on fresh water added artificial sea salt and seawater samples. Natural seawater was analyzed by the chemiluminescence method. The results obtained were compared with those obtained by chemical oxygen demand under the alkaline condition and total organic carbon methods. The chemiluminescence method has higher sensitivity and reproducibility than the conventional chemical oxygen demand and total organic carbon methods.

Chromatography, Liquid↗
PubMed2001

[The sedimentation rate and fractional dimension during flocculation with modified natural polymer and polymeric aluminum chloride].

The sedimentation rate and fractional dimension of the floc was studied during the process of the organic waste water treatment with modified natural polymer (CMS) and polymeric aluminum chloride (PAC). Irregular garrulous form of the floc was observed with microscope and electron-scanning microscope. The results showed that the sedimentation rate was 2.6 mm/min with the modified natural polymer (CMS) and 1.7 mm/min without CMS in condition of keeping the pH value to 6.86 and added quantity of PAC to 80 mg/L. The fractional dimension of the floc Df was calculated to be 1.70 in the best sedimentation rate.

Aluminum Chloride↗
PubMed2001

[Measurement of chlorodifluoromethane(HCFC-22) in the atmosphere by using an O2-induced electron capture detector (ECD)].

Chlorodifluoromethane (CHClF2, HCFC-22), a typical substitute of dichlorodifluoromethane(CF2Cl2, CFC-12), which atmospheric concentration was only at 10(-12) V/V level. After preconcentrated air sample, O2-Induced method was used to enhance sensitivity of ECD response to HCFC-22. When O2 concentration in carrier gas was 0.54%, there was the greatest value of S/N(signal to noise) and ECD response increased by about 500 times. With the study of other conditions, such as selection of the ECD temperature, programing of the column oven temperature and carrier gas flow, a practicable analysis method with high sensitivity of ECD was established.

Air↗
PubMed2001

[Anaerobic hydrolysis of terramycin crystallizing mother solution].

The terramycin crystallizing mother solution contained high organics and high nitrogen. There were many kinds of bioinhibition in it but not enough electronic donor. Anaerobic hydrolysis of terramycin crystallizing mother solution was completed with up anarobic sludge bed in order to improve the biodegradability of wastewater and electronic donor in it. The variations of pH, COD, NH4+, and SO4(2-) were monitored. The COD removal was in a narrow range between 10% and 16.4% even when the HRT of the reactor was changed from 1.5 h to 6 h. pH increased because of formation of NH3 and reduction of SO4(2-). Most of SO4(2-) was reduced to S2- when the HRT was longer than 2 h. Batch experiments on hydrolyzed wastewater demonstrated that reaction rates of nitrification and denitrification increased by 90.9% and 45.2%, respectively.

Anaerobiosis↗
PubMed2001

Murine antibody against E2 can capture hepatitis C virus in vitro.

OBJECTIVE: To find neutralizing antibody candidates against hepatitis C virus (HCV) infection. METHODS: We constructed two eukaryotic expression vectors which contained the E1 and E2 gene of HCV, and detected their expression in mammalian cells with transient expression. BALB/c mice were given subculaneous injections of constructed vectors combined with the IL-2 gene intraepidermally and evaluated for induced humoral immune responses by enzyme-linked immunosorbent assay (ELISA). We used an antibody-virus interaction assay to analyze the interaction of the antisera and HCV viral particles in vitro. RESULTS: Anti E1 and anti-E2 antisera were obtained from immunized mice. The serum of mice immunized with the E2 gene immunoprecipitated the HCV isolate in source serum and reacted with the isolates unrelated to the original one. CONCLUSIONS: Anti-E2 antibody in induced mice can cross-reactively capture HCV particles, highlighting the possibility of generating broadly reactive anti-E2 antibodies.

Animals↗
PubMed2001

Changes in intestinal microflora in patients with chronic severe hepatitis.

OBJECTIVE: To investigate changes in intestinal microflora in patients with chronic severe hepatitis (CSH), and their role in this life-threatening disease. METHODS: We classified nineteen patients with chronic severe hepatitis as the CSH group, thirty patients with chronic hepatitis (CH) as the CH group and thirty-one healthy volunteer as the control group. Fecal flora from all subjects were analyzed. Concentrations of plasma endotoxin, serum cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) and liver function were assessed. RESULTS: The number of fecal bifidobacterium (P < 0.001, P < 0.05 respectively), as well as bacteroidaceae (P < 0.001, P < 0.01 respectively) were significantly deceased in patients with chronic severe hepatitis compared with the CH and control groups, while the number of enterobacteriaceae (P < 0.001, P < 0.05 respectively) and yeasts (P < 0.01, P < 0.05 respectively) were significantly increased. Levels of plasma endotoxin, serum TNF-alpha, IL-1 beta and total bilirubin (TBiL) were significantly increased in the CSH group. The concentration of endotoxin positively correlated with levels of both TNF-alpha, IL-1 beta and TBiL (P < 0.001, respectively). Levels of plasma endotoxin were positively correlated with the number of fecal enterobacteriaceae and negatively correlated with bifidobacterium (P < 0.05, P < 0.001, respectively). CONCLUSION: Intestinal flora in patients with chronic severe hepatitis were severely disturbed and gut microbiological colonization resistance was impaired. Changes in intestinal flora may have a pivotal role in both the elevation of plasma endotoxin and further hepatic lesions resulting in liver failure.

Adult↗
PubMed2001

Treatment of hepatic failure with artificial liver support system.

OBJECTIVE: To assess the effectiveness of artificial liver support system (ALSS) treatment in patients with hepatic failure. METHODS: 235 cases of hepatic failure were treated with ALSS in our hospital. All data were analyzed by SPSS. The effectiveness of ALSS treatment was compared according to different stages (i.e., early, middle and end stages). RESULTS: 108 patients survived after therapy of ALSS. After each ALSS treatment, the liver function of these patients was greatly improved, the serum endotoxin and HBV-DNA concentrations were significantly decreased, and the serum concentration of aromatic amino acids (AAA) such as methionine decreased while the ratio of branched chain amino acids and aromatic amino acids (BCAA/AAA ratio) increased; patients treated with ALSS in the early or middle stages of disease had much higher survival rates than patients in the end stage of disease. CONCLUSION: ALSS is a reliable therapy for advanced liver diseases and treatment at early or middle stages is appropriate.

Adult↗
PubMed2001

Apolipoprotein E polymorphism in the early onset of coronary heart disease.

OBJECTIVE: To assess the relationship between apolipoprotein E (apoE) polymorphism and the early onset of coronary heart disease (CHD) and the effect of apoE on lipids and lipoproteins in healthy Chinese subjects. METHODS: Sixty-eight patients with CHD younger than 55 years (CHD1), 136 patients with CHD older than 65 years (CHD2), and 136 healthy subjects were enrolled, and their plasma levels of triglyceride (TG), total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) were determined. The apoE genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: apoE 3/4 genotype and E4 allele frequency in the CHD1 group were higher than those in the CHD2 group and healthy subjects, while no differences were found between CHD2 and healthy subjects. Meanwhile, the plasma levels of TC and low density lipoprotein cholesterol (LDL-C) were higher in the CHD2 group than in both CHD1 group and healthy subjects. Each apoE isoprotein has variable TC and LDL-C levels that is E2 (E2/2 + E2/3) < E3(E3/3) < E4(E4/4 + E3/4). CONCLUSION: apoE is one of the genetic factors that affect TC and LDL-C levels, and apoE 4 has a very close relation to CHD, suggesting that apoE 4 is an independent genetic factor of the early onset of CHD.

Adult↗
PubMed2001

Clinical and familial study of arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVE: To explore the characteristics of arrhythmogenic right ventricular cardiomyopathy (ARVC). METHODS: Seven patients with arrhythmogenic right ventricular cardiomyopathy and 34 members of three families were studied. All patients and family members underwent history collection, clinical examination, electrocardiogram (ECG), two-dimensional echocardiography (2-DE) and a signal averaging electrocardiogram. Programmed ventricular stimulation was performed in five patients. RESULTS: All patients and family members had normal morphologic characteristics and normal function of the left ventricular by 2-DE. Fourteen persons had abnormal findings indicating ARVC. Five had enlargement of the right ventricular with diffused hypocontractility, eight had thin and systolic bulging in the focal anterior wall with hypokinesia and one had bulging of the inferior wall. Twenty-five persons (seven patients and 18 family members) had abnormal findings in ECG. Positive ventricular late potential was recorded in 13 persons (six patients). Two to three monomorphic ventricular tachycardia (VT) with left bundle branch block (LBBB) configurations were induced in five patients. Ventricular fibrillation was induced in two patients during the electrophysiologic study (EPS). Five patients had very high pacing threshold and/or ineffective pacing in one or many regions of the right ventricle. Two members of one family died suddenly. One member was a dwarf with ARVC. Spontaneous VT with a left bundle branch block (LBBB) configuration was recorded in five patients, polymorphic VT with extremely short coupling interval in one, and premature ventricular complexes with LBBB configuration in 12 (six patients). CONCLUSION: Our familial study strongly suggests that ARVC may be a hereditary disease and it is helpful in the diagnosis and detection of ARVC. The most common manifestations were abnormal structure and function of the right ventricle and abnormal ECG of repolarization and ventricular arrhythmia which originates from the right ventricle.

Adolescent↗
PubMed2001

[Study on the intestinal microbial colonization resistance in patients with chronic severe hepatitis].

OBJECTIVE: To investigate the changes of microbial colonization resistance of the bowel in patients with chronic severe hepatitis. METHODS: The fecal flora bifidobacteria, enterobacteriaceae, enterococci, and yeasts of subjects (chronic severe hepatitis, chronic hepatitis, and healthy volunteers) were quantitatively and qualitatively analyzed by Mitsuoka's methods. While the ratio of bifidobacterium to enterobacteriaceae ( B/E ratio ) was calculated. RESULTS: The number of bifidobacteria and the B/E ratio in chronic severe hepatitis group was significantly deceased compared with that of the control group (P<0.001). The number of enterobacteriaceae and yeasts was significantly increased compared with that of control group (P<0.001 and P<0.01, respectively). CONCLUSIONS: The results suggest that the intestinal microbial colonization resistance in patients with chronic severe hepatitis is seriously impaired.

Bifidobacterium↗
PubMed2001

[Clinical application of narcotic analgesics in patients with burn and plastic surgery].

OBJECTIVE: To investigate the effects of narcotic analgesics (opioids) on the patients with burn and plastic surgery. METHODS: Retrospective statistical analysis was carried out in 452 patients with burn and plastic surgery in terms of the clinical signs of pain, the number of the patients who used the drug, the kinds of the drugs used, the doses and the number of use each day. RESULTS: Inappropriate and insufficient application of narcotic analgesics was common in the past due to our incomplete knowledge of the importance of postburn and post-operative pain in patients with burn and plastic surgery, and also confused concepts of the pain and misuse of opioids, often leading to insufficient analgesia. CONCLUSION: Much attention should be paid to navcotic analgesia in patients with burn plastic surgery. Some measures were suggested.

Adolescent↗
PubMed2001

[The diagnosis and treatment of large cervical vascular injury].

OBJECTIVE: To study the diagnosis and treatment of large cervical vascular injury, and to improve the treatment. METHODS: Clinical data of 18 cases of large cervical vascular injury between 1974 and 1999 in the Medical College Second Affiliated Hospital of Zhejiang University were analyzed retrospectively. RESULTS: The following injuries were found, including common carotid artery involvement in 7, external carotid artery in 4, internal carotid artery in 2, subclavian artery in 1, internal jugular vein in 4. The type of injury included incision injury in 8, laceration injury in 5, break injury in 2, inflammatory injury in 2, tumor injury in 1. Fifteen cases were diagnosed by active bleeding of wound in neck, 2 cases by color Duplex ultrasound, 1 case by exploration. Operation included vascular repair in 8, vascular ligation in 10. The result showed that 14 patients were cured, one patient developed light hemiplegia, one patient performed amputation of the arm due to necrosis after subclavian artery ligation, two patients died, the mortality rate was 11.1%. CONCLUSION: Active profuse bleeding from the neck wound is the basis of diagnosis basis. Rational surgical treatments are needed immediately.

Adolescent↗
PubMed2001

Progress in DNA chip technology.

DNA chip technology employs light-directed in situ oligonucleotide synthesis and/or DNA microarray printing device to produce arrays of large number of probes in the tiny surface of silicon substrates, which makes it possible that the gene detection be conducted efficiently with high speed and sensitivity. The DNA chip may take important part in genome research, gene diagnoses and so on.

Animals↗
PubMed2001

[Analysis of the lineshape of laser frequency modulation].

In this paper, we analyze the dependence of the output signal spectral lineshape and intensity on the modulation, waveform and modulation index in first- and second-harmonic detection of triangle modulation, square demodulation and saw modulation square demodulation. The signal lineshape in the case of saw modulation, square demodulation is quite different from, whereas the signal lineshape in the case of triangle modulation, square demodulation is similar to that in traditional sine modulation, sine demodulation. Experiments of tunable IR laser frequency modulation absorption spectrum of methane are also done to verify the theoretical analysis. Then we reach a conclusion; the lineshape and intensity of frequency modulation spectrum can be influenced by modulation waveform, demodulation waveform and modulation index. Calculation results can be used to choose better experimental parameters and optimize experimental designs.

Algorithms↗