Biomedical subjects

B Wen

Publications and source records attributed to B Wen.

At least 19 recordsLinked to original sources

PubMed2003

n-3 polyunsaturated fatty acids decrease mucosal/epidermal reactions and enhance antitumour effect of ionising radiation with inhibition of tumour angiogenesis.

The purpose of this study was to evaluate the effect of n-3 polyunsaturated fatty acids (n-3 PUFAs) on normal tissue (lip mucosa) and tumour growth when combined with ionising radiation. The oral region (snout) of C57 black mice was irradiated with 16.5 Gy and n-3 PUFAs (100 microl) were injected intravenously for 2 weeks. After exposure to irradiation, the degree and duration of the acute reactions decreased significantly when mice were treated with n-3 PUFAs as compared to the control group. Interestingly, the range of the reactions in the n-3 PUFAs-treated group compared favourably to the group receiving amifostine (27.5 mg/kg i.v.). the effect of n-3 PUFAs was further evaluated in HEP-2 human carcinoma xenograft transplanted in nude mice. An inhibition of tumour growth was observed when mice were treated with n-3 PUFAs alone and this effect was maximal when combined with irradiation. Similar results were obtained using eicosapentaenoic acid. The effect of n-3 PUFAs was associated with inhibition of angiogenesis and tumour proliferation, and significantly decreased expression of cyclooxygenase-2. In conclusion, n-3 PUFAs administration decrease mucosal response, while moderately enhancing the antitumour effect of irradiation. The magnitude of the differential effect suggests that n-3 PUFAs need to be further investigated in the clinic.

Animals↗

PubMed2001

Tyrphostin AG 1024 modulates radiosensitivity in human breast cancer cells.

Insulin-like growth factor-1 (IGF-1) plays an important growth-promoting effect by activating the PI3K/Akt signalling pathway, inhibiting apoptotic pathways and mediating mitogenic actions. Tyrphostin AG 1024, one selective inhibitor of IGF-1R, was used to evaluate effects on proliferation, radiosensitivity, and radiation-induced cell apoptosis in a human breast cancer cell line MCF-7. Exposure to Tyrphostin AG 1024 inhibited proliferation and induced apoptosis in a time-dependent manner, and the degree of growth inhibition for IC20 plus irradiation (4 Gy) was up to 50% compared to the control. Examination of Tyrphostin AG 1024 effects on radiation response demonstrated a marked enhancement in radiosensitivity and amplification of radiation-induced apoptosis. Western blot analysis indicated that Tyrphostin AG 1024-induced apoptosis was associated with a downregulation of expression of phospho-Akt1, increased expression of Bax, p53 and p21, and a decreased expression of bcl-2 expression, especially when combined with irradiation. To our knowledge, this is the first report showing that an IGF-1 inhibitor was able to markedly increase the response of tumour cells to ionizing radiation. These results suggest that Tyrphostin AG 1024 could be used as a potential therapeutic agent in combination with irradiation.

Adenocarcinoma↗

PubMed2001

[Using L-form bacterium ATP bioluminescence assay for rapid testing L-form bacterial susceptibility].

Adenosine triphosphate is a kind of necessary metabolites in living cells. The authors detected ATP contents by using bioluminescence method in 111 strains of L-form bacteria after exposing to 5 kinds of antibiotics. The results showed that the mean value of CPM was less than (35 +/- 10.2)%.s-1. Thus, the value could be acted as a critical concentration between susceptibility and resistance. The conincidence rate of this method and K-B method was 95.3%. It indicates that the bioluminescence method has a high sensitivity. It can be used to detect L-form bacterium-drug susceptibility quickly and may play an important role for choosing the antibiotics.

Adenosine Triphosphate↗

PubMed2001

Uptake and distribution of rare earth elements in rice seeds cultured in fertilizer solution of rare earth elements.

The uptake behavior of rare earth elements (REEs) under pot conditions using deionized water and a REE fertilizer solution as the culture media as well as the distribution of REEs in rice proteins were studied. The uptake of REEs in rice seeds increased dramatically after a lag period of approximately three days. Roots can accumulate a much higher content of REEs than germs and the resting seeds. The REE content in each water-soluble (albumin) and salt-soluble (globulin) component of the rice seeds accounted for 5-8% and 4-6% of the total REEs, respectively. However, there are less than 1.5% of the total REEs were found in the alcohol-soluble (prolamin) and acetic acid-soluble (glutelin) components. The high performance liquid chromatography (HPLC) in the gel permeation and the reserved-phase were used to monitor changes in the molecular weight distribution changes of the soluble proteins of rice seeds during germination after having been cultured in the same solution for seven days. No changes occurred in the prolamin, while a slight change occurred in the albumin, globulin and glutelin. Fractionation of the albumin of rice seeds cultured in a REE fertilizer solution on the Sephadex G-100 column indicated that REEs, especially Ce, La, Pr and Nd, were associated mainly with biological compounds of a molecular weight between 10,000 and 12,000.

Absorption↗

PubMed2001

Isolation and characterization of rare earth element-binding protein in roots of maize.

Rare earth element-binding protein was isolated from maize, which was grown under greenhouse conditions and characterized in terms of molecular weight, amino acid composition, and ultraviolet absorption. The molecular weight of the maize protein was determined to be 183,000, with two distinct subunits of approximately molecular weights of 22,000 and 69,000, respectively. The protein is particularly rich in asparagine/aspartic acid, glutamine/glutamic acid, glycine, alanine, and leucine and contains 8.0% of covalently bound carbohydrate. The ultraviolet absorption of the protein is low at 280 nm and no change in the adsorption was observed with a change in pH. Compared to the unique features of the metallothioneins with a molecular weight of approximately 10,000, a high cysteine content of 30%, high absorption at 254 nm and a low absorption at 280 nm, and absorption change with pH, the REE-binding protein is unlikely to be plant metallothionein in nature. It was found that an almost twofold greater concentration was found for most of the REEs in the protein isolated from the maize with REE fertilizer use than that without REE fertilizer. This study suggests that the REE-binding protein is a glycoprotein and REEs can be firmly bound with the protein of maize roots.

Amino Acids↗

PubMed2000

Freedericksz transition in an anticlinic liquid crystal

It is shown experimentally that a very-long-pitch, surface-stabilized, anticlinic liquid crystal undergoes a two-step electric-field-induced transition to the synclinic phase. The liquid crystal remains undistorted below a threshold field E(th). For E>E(th), a Freedericksz transition occurs, wherein molecules in adjacent smectic layers undergo unequal azimuthal rotations about the layer normal. At higher fields a transition to the synclinic phase occurs via solitary waves.

Journal Article↗

PubMed2000

Freedericksz transition in an anticlinic liquid crystal

The Freedericksz geometry is used to show experimentally that a very-long-pitch, surface stabilized, anticlinic liquid crystal undergoes a two-step electric-field-induced transition to the synclinic phase. The liquid crystal remains undistorted below the threshold field E(th). For E>E(th), a Freedericksz transition occurs, wherein molecules in adjacent smectic layers undergo unequal azimuthal rotations about the layer normal, resulting in a nonzero polarization that couples to the applied field. Measurements of E(th) as a function of temperature are reported. Related quasielastic light scattering measurements demonstrate that acoustic Goldstone mode fluctuations are quenched by a dc electric field E>E(th). At high fields a transition to the synclinic phase occurs via solitary waves.

Journal Article↗

PubMed2000

[Relationship between CYP1A1, GSTM1 genetic polymorphisms and susceptibility to esophageal squamous cell carcinoma].

OBJECTIVE: To investigate the association between susceptibility of esophageal squamous cell carcinoma and the genetic polymorphisms of CYP1A1 and GSTM1. METHODS: Subjects were comprised of 107 esophageal cancer patients and 111 healthy controls. Genotyping of both CYP1A1 and GSTM1 were performed in cancer tissues of all 107 patients and peripheral blood leukocytes taken from the controls by polymerase chain reaction. RESULTS: There were no significant differences in the frequency distribution of CYP1A1 polymorphisms between esophageal cancer patients and healthy controls although the frequency of CYP1A1 with at least one allele of Val showed slightly higher in individuals with esophageal cancer. However, significant difference was observed in the frequency of GSTM1-nulled individuals with esophageal cancer comparing with the controls (P < 0.05). When subjects were categorized by both CYP1A1 genotype and GSTM1 genotype, GSTM1 (-) became markedly expressed in patients with CYP1A1 (I/I) than in the corresponding controls (67% versus 40%, P < 0.01). The frequency of CYP1A1 genotype with at least one allele of Val (I/V and V/V) was also statistically higher in patients with GSTM1 (+), comparing to the corresponding controls (64% versus 41%, P < 0.05). CONCLUSIONS: It was suggested that: genetic polymorphisms of CYP1A1 and GSTM1 were susceptible to esophageal cancer; individuals who are GSTM1-null have an increased risk of developing esophageal cancer; individuals with combined CYP1A1 (I/I) and GSTM1 (-) or with combined CYP1A1 (I/V, V/V) and GSTM1 (+) were more susceptible, when comparing to those with combined CYP1A1 (I/I) and GSTM1 (+).

Adult↗

PubMed2000

[Bacteriological analysis of chronic sinusitis in school-age children (36 cases report)].

OBJECTIVE: To research the bacteriological characters of chronic sinusitis in school-age children and to provide basis for clinical treatment. METHOD: The purrent discharges taken from middle meatus of 36 patients were cultured for bacteria and the antimicrobial suscepility was determined. RESULT: The positive rate of bacteria culture was 83.3%, the compound infection rate was 36.1%. Aerobic bacteria were present in 76.7%, anaerobic bacteria were present in 55.6%. The result of antimicrobial susceptibility test was scattered. CONCLUSION: Infection rate of anaerobic bacteria was high in chronic sinusitis in school-age children and result of antimicrobial susceptibility was scattered. It was important to have anti-anaerobic treatment in chronic sinusitis in school-age children and to take an antimicrobial susceptibility test before medical treatment.

Adolescent↗

PubMed1999

Autologous peripheral blood stem cell transplantation for Waldenstrom's macroglobulinemia.

We report a 50-year-old male patient with Waldenstrom's macroglobulinemia poorly responsive to conventional chemotherapy, who went on to receive high-dose melphalan as conditioning before autologous PBSC infusion. Autologous hematopoiesis was reconstituted 5 weeks after transplant. Complete remission was confirmed by blood and marrow examination. The patient remains well at 12 months, with no detectable monoclonal IgM in his serum and absence of plasmacytoid lymphocytes in his marrow. Our results suggest that, at least in this case, high-dose chemotherapy with autologous PBSC support was an effective therapeutic approach for Waldenstrom's macroglobulinemia.

Hematopoietic Stem Cell Transplantation↗

PubMed1999

[Morphological changes of external eyes before and after blepharoplasty].

OBJECTIVE: To discuss the morphological changes of external eyes before and after blepharoplasty. METHODS: A survey of 92 patients treated by blepharoplasty was carried out to compare the external eye morphology of pre-operation with that of post-operation. RESULTS: It was found significant differences in the post-operative patients, including the increased length and height of eyelids, and obvious changes of the length and angle of the exposed eyelashes. CONCLUSION: Blepharoplasty makes the eyelashes exposed and held up, and increases the up-to-low distance of eyelids. These changes promote the beauty of eyes.

Adolescent↗

PubMed1999

[Analysis of the relationship between the facial skin temperature and blood flow].

The relationship between the blood flow of temperal or facial artery and facial skin temperature was studied in 30 patients with facial nerve paralysis. The facial skin temperature was recorded by infrared thermography, and the blood flow was measured by ultrasonic Doppler flowetry. The results showed, in the same facial region, the greater the volume of blood flow was, the higher the skin temperature stood. After acupuncture on the facial points, the facial blood flow increased and the facial skin temperature rose. The ratios between the increase in facial skin temperature and the in increase in blood flow were 0.9538-1.2835(degrees:ml/second) in four facial regions. These indicate the presence of certain quantitative relationship between the facial blood flow and the skin temperature.

Adult↗

PubMed1997

Ultrastructural and antigenic characterization of a granulocytic ehrlichiosis agent directly isolated and stably cultivated from a patient in New York state.

A human granulocytic ehrlichiosis (HGE) agent with 16S rDNA sequence identical to the published sequence of HGE agents was isolated from a patient from New York State by inoculation of the blood leukocyte fraction directly into a human promyelocytic leukemia cell line HL-60. The HGE agent was also isolated from the leukocyte fraction of the blood and bone marrow of a mouse inoculated with the leukocyte fraction of the patient's blood. The isolate has been passaged in tissue culture 30 times over 8 months. Electron microscopy revealed pleomorphic coccobacilli with a thin and highly rippled outer membrane in the clear inclusion matrix. Comparison of IFA reactivity of antisera obtained from a variety of sources with the cell-cultured HGE agent revealed that 3 HGE agent strains (New York isolate, Wisconsin [BDS] isolate, and a tick-derived isolate) are highly cross-reactive and there are diverse antigenic cross-reactivities between HGE agent and Ehrlichia chaffeensis.

Aged↗

PubMed1997

Western immunoblot analysis of Haemobartonella muris and comparison of 16S rRNA gene sequences of H. muris, H. felis, and Eperythrozoon suis.

Infectious agents were isolated from the spleens of three wild mice (Apodemus argenteus) by intraperitoneal inoculation of the spleen homogenate into laboratory mice. The laboratory mice developed clinical signs and splenomegaly, and three isolates were maintained by passage in mice. Tetracyclines were effective in preventing infection of mice with these agents, but streptomycin and penicillin were ineffective. The agents did not grow in bacterial growth media or chicken embryos. In smears of blood from infected mice stained by the Giemsa or the indirect immunofluorescence method, numerous organisms were found on the surfaces of erythrocytes. Electron microscopy revealed cell wall-less pleomorphic cocci of 350 to 700 nm in diameter. On the basis of these results, the isolates were identified as Haemobartonella muris. There was no antigenic cross-reactivity with Rickettsia or Ehrlichia spp. or other related organisms. Western immunoblot analysis of three strains of H. muris with mouse antisera to H. muris revealed identical major antigens of 118, 65, 53, 45, and 40 kDa. By heteroduplex analysis of the three PCR-amplified segments of the 16S rRNA genes, the three strains of H. muris were found to be identical. The 16S rRNA genes of one of the H. muris strains, four strains of H. felis, and two strains of Eperythrozoon suis were sequenced and compared. The sequences of two strains of H. felis from cats in California were identical, as were the sequences of a strain from a cat in Ohio and a strain from a cat in Florida, but the similarity of sequences between the California and the Ohio-Florida strains was only 85%. The sequence of an H. muris strain was unique and was more closely related to that of the Ohio-Florida strain of H. felis (89%) than to that of the California strain of H. felis (84%). The sequence of E. suis from a pig in Illinois was identical to that from another pig from Taiwan. The similarity of the 16S rRNA gene sequence of E. suis with those of three Haemobartonella strains was 84 to 92%, with that of E. suis being most similar to that of the H. felis strain from California. In the phylogenetic analysis based on 16S rRNA gene sequences, the Haemobartonella spp. and E. suis formed a distinct clade more closely related to Mycoplasma spp. (79 to 83% similarity) than to Anaplasma marginale (72 to 75% similarity). Our results suggest that the Haemobartonella spp. and E. suis may be reclassified in the same genus in the family Mycoplasmataceae.

Anaplasmataceae↗

PubMed1997

Comparison of nested PCR with immunofluorescent-antibody assay for detection of Ehrlichia canis infection in dogs treated with doxycycline.

A partial 16S rRNA gene was amplified in Ehrlichia canis-infected cells by nested PCR. The assay was specific and did not amplify the closely related Ehrlichia chaffeensis, Ehrlichia muris, Neorickettsia helminthoeca, and SF agent 16S rRNA genes. The assay was as sensitive as Southern hybridization, detecting as little as 0.2 pg of E. canis DNA. By this method, all blood samples from four dogs experimentally infected with E. canis were positive as early as day 4 postinoculation, which was before or at the time of seroconversion. One hundred five blood samples from dogs from Arizona and Texas (areas of E. canis endemicity) and 30 blood samples from dogs from Ohio (area of E. canis nonendemicity) were examined by nested PCR and immunofluorescent-antibody (IFA) test. Approximately 84% of dogs from Arizona and Texas had been treated with doxycycline before submission of blood specimens. Among Arizona and Texas specimens, 46 samples were PCR positive (44%) and 80 were IFA positive (76%). Forty-three of 80 IFA-positive samples (54%) were PCR positive, and 22 of 25 IFA-negative samples (88%) were negative in the nested PCR. None of the Ohio specimens were IFA positive, but 5 specimens were PCR positive (17%). Our results indicate that the nested PCR is highly sensitive and specific for detection of E. canis and may be more useful in assessing the clearance of the organisms after antibiotic therapy than IFA, especially in areas in which E. canis is endemic.

Animals↗

PubMed1997

[Rapid bioluminescence method for pathogen detection of nephropyelitis patient].

ATP is a kind of necessary metabolites in the living cells. We detected ATP contents in 222 bacteriuria or the urine germ by bioluminescence method. The results showed that the patient had been infected when the mean value was > 130.9 +/- 11.38 and had not when the mean value was < 32.9 +/- 2.26. The results were the same with the Gram Stain, L-form bacteriuria culture and the common bacteriuria culture. The mean values of positive specimens are higher than that of the negative specimens by the bioluminescence. Thus, it is indicated that the bioluminescence method has high sensitivity. This method can be used to detect L-form bacteriuria in the urine germ quickly and is important for early diagnosis by the doctors.

Adenosine Triphosphate↗

PubMed1996

Identification and cDNA cloning of a novel human mosaic protein, LGN, based on interaction with G alpha i2.

We have used the yeast two-hybrid system to identify proteins that interact with the alpha-subunit of the heterotrimeric GTP-binding protein, Gi2. We screened a human B cell cDNA library with full-length G alpha i2 and isolated four positive colonies, one of which expressed the 44-kDa COOH terminus of a previously unrecognized 677-amino acid (aa) protein. A full-length clone was isolated from a HeLa cell cDNA library. The deduced protein contains 10 Leu-Gly-Asn repeats, and thus we named it LGN. Computer analysis indicates that LGN is a mosaic protein with seven repeated sequences of about 40 aa in length at its N-terminal end, and four repeated sequences of about 34 aa at its C-terminal end. Each of the two repeat regions shows substantial similarity to proteins found in other organisms. RT-PCR analysis of human tissues showed that the mRNA of LGN was ubiquitously expressed. The specificity of interaction between G alpha i2 and LGN was confirmed by an in vitro binding assay using recombinant proteins. These data indicate that the yeast two-hybrid system can identify novel proteins, such as LGN, that interact with G alpha proteins. As a mosaic protein, LGN shows similarity with portions of proteins from many species and thus may define a new protein family.

Amino Acid Sequence↗

PubMed1996

Characterization of the SF agent, an Ehrlichia sp. isolated from the fluke Stellantchasmus falcatus, by 16S rRNA base sequence, serological, and morphological analyses.

The organism designated the SF agent was originally isolated in Japan in 1962 from Stellantchasmus falcatus metacercaria parasitic on gray mullet fish. The SF agent resembles members of the genus Ehrlichia morphologically and exhibits weak antigenic cross-reactivity with Ehrlichia sennetsu. This organism causes mild clinical signs in dogs, but severe splenomegaly and lymphadenopathy in mice. This suggests that the SF agent may be similar to either Neorickettsia helminthoeca, an intracellular parasite of a fluke and the cause of salmon poisoning disease in dogs, or E. sennetsu, the causative agent of human sennetsu ehrlichiosis in Japan and Malaysia. In order to determine the phylogenetic relationship between the SF agent and other ehrlichial species, the 16S rRNA gene was amplified by the PCR and sequenced. The SF agent sequence was most closely related to the sequences of Ehrlichia risticii (level of sequence similarity, 99.1%), the causative agent of Potomac horse fever, and E. sennetsu (level of sequence similarity, 98.7%). The next most similar sequence was that of N. helminthoeca, but the level of sequence similarity was only 93.7%. E. sennetsu, E. risticii, the SF agent, and N. helminthoeca formed a distinct cluster that was separated from all other ehrlichial species. As determined by immunofluorescence labeling, antiserum against the SF agent cross-reacted strongly with E. sennetsu, E. risticii, and N. helminthoeca. When three genetically distinct ehrlichial isolates obtained from horses with Potomac horse fever were compared with the SF agent, we found that the SF agent was most closely related to Ohio isolate 081, followed by IllinoisT (T = type strain) and a Kentucky isolate. We observed strong antigenic cross-reactivities and similarities in Western blot (immunoblot) reaction profiles when we compared the SF agent, E. risticii, and E. sennetsu; however, weaker antigenic cross-reactivity was observed when the SF agent and N. helminthoeca were compared. Our results indicate that the SF agent is antigenically more closely related to E. risticii and E. sennetsu than to N. helminthoeca. The biological and antigenic characteristics and the 16S rRNA sequence data suggest that the SF agent is a new species that belongs to the genus Ehrlichia.

Animals↗