Biomedical subjects

Bin Cheng

Publications and source records attributed to Bin Cheng.

At least 19 recordsLinked to original sources

PubMed2025

Cerebrospinal fluid microbiome revisited: no evidence of resident bacteria in archived samples.

UNLABELLED: DNA from oral bacteria has been detected in the cerebrospinal fluid (CSF) of patients with Alzheimer's disease and related dementias (AD/ADRD). We hypothesized that examination of archived CSF samples from donors with variable cognitive status would reveal evidence of a resident microbiome. 176 CSF samples harvested from community-dwelling individuals (77% between 61 and 80 years old) were analyzed; 57% originated from donors with impaired cognitive status. DNA was extracted after adding microbial spike-in controls, and libraries were prepared and sequenced on an Illumina-MiSeq platform. 16S rRNA sequences were processed, and a taxonomic classification was performed. Spike-in bacteria were consistently detected, and Streptococcus pneumoniae was found in a positive control sample from a patient with bacterial meningitis. However, very few reads mapping to other bacterial taxa were detected across samples, suggesting a negligible bacterial content consistent with occasional contamination or sequencing errors. CSF is a privileged, sterile environment that does not harbor a resident microbiome in elderly people with various morbidities, including AD/ADRD. IMPORTANCE: Recent reports have suggested that DNA from oral bacteria has been found in the cerebrospinal fluid (CSF) of patients with Alzheimer's disease and related dementias (AD/ADRD). We hypothesized that examination of archived CSF samples from donors with variable cognitive status would reveal evidence of a resident microbiome. We thus analyzed 176 CSF samples harvested from community-dwelling individuals including donors with impaired cognitive status. While our findings suggested the presence of occasional bacterial contamination, they provided no evidence of a resident microbiome. We thus conclude that the CSF is indeed a privileged, sterile environment that does not harbor a resident microbiome in elderly people with various morbidities including AD/ADRD.

Humans↗

PubMed2007

Frequent mutation of p16(CDKN2A) exon 1 during rat tongue carcinogenesis induced by 4-nitroquinoline-1-oxide.

In this study we explored the mutation types of p16(CDKN2A) exon 1 and the corresponding frequencies in experimental rat tongue carcinogenesis. Twenty barrier Sprague-Dawley (SD) rats were divided into the control (n = 5) and experimental group (n = 15), to which 4-nitroquinoline-1-oxide (4-NQO) in drinking water was administered. Two samples of normal, three samples of moderate/severe dysplasia and four samples of invasive squamous cell carcinoma lesions were selected following strict histopathological examination in double-blind manner. The PCR products of p16(CDKN2A) exon 1 amplified from these tissues were sequenced. Point mutations of p16(CDKN2A) exon 1 were found in all of the precancerous and cancerous lesions. Half of the mutations were detected on guanine (G). Twenty mutations, including a missense mutation of the start codon resulting in alternative reading frame of p16(CDKN2A) exon 1, were also identified. These preliminary results suggested that mutation of p16(CDKN2A) exon 1 might be an early molecular event of rat tongue carcinogenesis induced by 4NQO and G was the mutation hotspot.

4-Nitroquinoline-1-oxide↗

PubMed2006

Delays in breast cancer diagnosis and treatment by racial/ethnic group.

BACKGROUND: Although white women have the highest incidence of breast cancer, African American, followed by Hispanic, American Indian/Alaskan Native, and Asian American or Pacific Islander, women have higher death rates from the disease. Timely initiation of treatment has been shown to improve survival, and may help to lessen the mortality differences among racial/ethnic groups. METHODS: The purpose of this study was to describe time delays in the initial diagnosis and treatment of primary breast carcinoma across diverse ethnic/racial groups. Data are from the Surveillance, Epidemiology, and End Results-Medicare database. Women in this study were diagnosed as having breast cancer between January 1, 1992, and December 31, 1999. Billing claims from outpatient and inpatient visits were used. A total of 49 865 female Medicare recipients 65 years and older were enrolled in the study. Racial/ethnic groups were compared in their diagnostic, treatment, and clinical delay (ie, women with a diagnostic and treatment delay). RESULTS: African American women experienced the greatest diagnostic, treatment, and clinical delay. After controlling for other predictors, compared with white women, African American women had a 1.39-fold odds (95% confidence interval, 1.18-1.63) of diagnostic delay beyond 2 months, a 1.64-fold odds (95% confidence interval, 1.40-1.91) of treatment delay beyond 1 month, and a 2.24-fold odds (95% confidence interval, 1.75-2.86) of having a combined clinical delay. CONCLUSIONS: In a population-based study, African American women experienced the most delays in initial diagnosis and initiation of breast cancer treatment, relative to women of other racial/ethnic subgroups. Despite the limitations of a claims database, the magnitude and direction of the findings are consistent across the research, suggesting the critical importance of reducing these delays.

Black or African American↗

PubMed2006

Superhydrophobic behavior of a perfluoropolyether lotus-leaf-like topography.

We demonstrate the fabrication of 2-D arrays of nanopillars made from perfluoropolyether derivatives using a porous anodic aluminum oxide membrane as a template. Pretexturing the aluminum prior to anodization enables one to engineer multiple morphological length scales and thereby synthesize a lotus-leaf-like topography. Both nanopillars on a flat surface and on a lotus-leaf-like topology exhibit superhydrophobicity, low contact angle hysteresis, and self-cleaning.

Aluminum Oxide↗

PubMed2006

Anti-apoptotic and neuroprotective effects of Tetramethylpyrazine following spinal cord ischemia in rabbits.

BACKGROUND: Tetramethylpyrazine (TMP) is one of the most important active ingredients of a Chinese herb Ligusticum wallichii Franchat, which is widely used in many ischemia disorders treatments. However, the exact mechanism by which TMP protects the spinal cord ischemia/reperfusion (I/R) injury is still unknown. For this purpose, rabbits were randomly divided into sham group, control group and TMP group. After the evaluation of neurologic function, the spinal cords were immediately removed for biochemical and histopathological analysis. Apoptosis was measured quantitatively by the terminal transferase UTP nick end-labeling (TUNEL) method and confirmed by electron microscopic examination, the expression of Bax and Bcl-2 was immunohistochemically evaluated and quantified by Western blot analysis. RESULTS: Neurologic outcomes in the TMP-group were significantly better than those in the control group (P < 0.05). TMP decreased spinal cord malondialdehyde (MDA) levels and ameliorated the down regulation of spinal cord superoxide dismutase (SOD) activity. TMP significantly reduced the loss of motoneurons and TUNEL-positive rate. Greater Bcl-2 and attenuated Bax expression was found in the TMP treating rabbits. CONCLUSION: These findings suggest that TMP has protective effects against spinal cord I/R injury by reducing apoptosis through regulating Bcl-2 and Bax expression.

Animals↗

PubMed2006

Synthesis of variable-aspect-ratio, single-crystalline ZnO nanostructures.

Variable-aspect-ratio (length/diameter), one-dimensional (1-D) ZnO nanostructures (nanorods and nanowires) were prepared in alcohol/water solution by reacting a Zn2+ precursor with an organic weak base, tetramethylammonium hydroxide (Me4NOH). The effect of the experimental parameters (temperature, base concentration, reaction time, and water content) on nucleation, growth, and the final morphology of the ZnO nanostructures was investigated. The low-temperature syntheses (75-150 degrees C) yielded aspect ratios of the 1-D ZnO nanostructures that depended on the water content. The individual ZnO nanorods and nanowires were determined to be perfect, single crystals with their c axes as the primary growth direction.

Alcohols↗

PubMed2006

Long-term outcomes of malignant phyllodes tumors patients: an institutional experience.

BACKGROUND: Malignant phyllodes tumors are an extremely rare breast tumor. Prognostic features and overall survival data have not been consistent across studies. METHODS: Retrospectively, we examined the clinicopathologic features of 27 breast cancer patients treated for malignant phyllodes tumors from 1995 to 2004 and analyzed their recurrence and survival outcomes using contingency tables, a logistic regression model, or a proportional hazard model. RESULTS: The mortality rate was 12% (n = 3) of the cohort and 75% of the group with distant metastases. The median follow-up period was 51 months (range, 12-192 mo). A mitotic index greater than 10 per high-powered field, the presence of stromal overgrowth, mastectomy at initial surgery, and larger tumor size were associated with an increased incidence of distant metastases. Larger tumor size also was associated with an increased incidence of death. CONCLUSIONS: Most patients with malignant phyllodes tumors will enjoy significant long-term survival if treated appropriately with local excision with clear margins.

Adolescent↗

PubMed2006

On the assessment of dose proportionality: a comparison of two slope approaches.

The problem for assessment of dose proportionality (or linearity) is studied. Various methods for assessment of dose proportionality (or linearity) such as ANOVA type F-test have been proposed. Cheng et al. (2006) proposed an alternative approach based on the slopes of adjacent dose levels under a crossover design. They showed that when dose proportionality (or linearity) cannot be established, their proposed slope approach is useful for evaluation of the degree of departure from dose proportionality (or linearity). In this article, we propose the use of slopes between the dose level and the initial dose (baseline), which we refer to as the baseline slope approach. The two slope approaches are compared under a parallel group design by means of an ANOVA type F-test and other tests. Simulation studies show that the proposed method has a satisfactory small sample performance.

Analysis of Variance↗

PubMed2006

Short-term clinical evaluation of intralesional triamcinolone acetonide injection for ulcerative oral lichen planus.

BACKGROUND: Efforts are made in a continued searching for novel therapies for symptomatic oral lichen planus (OLP). This study aimed to evaluate the efficacy and safety of intralesional triamcinolone acetonide (TA) injection for ulcerative OLP. METHODS: Forty-five patients with clinical and histologically confirmed ulcerative OLP on bilateral buccal mucosa, one for treatment and the other for control, were studied. All participants received 0.5 ml TA (40 mg/ml) on experimental sites. Visual analogue scale score and lesion areas were recorded at the time of injection and 1-week interval. After 2 weeks, if the treated ulceration reduced < 81% in size, a second injection was given. RESULTS: The treated group gave rapid relief of signs and symptoms, while the control group showed minimal decrease. 38 (84.4%) patients demonstrated complete response in ulceration size. No complications were noted with TA injections. CONCLUSIONS: Intralesional TA injection in ulcerative OLP is effective and safe in achieving lesion and pain regression.

Adult↗

PubMed2006

Periodontal changes in children and adolescents with diabetes: a case-control study.

OBJECTIVE: To evaluate the level of oral disease in children and adolescents with diabetes. RESEARCH DESIGN AND METHODS: Dental caries and periodontal disease were clinically assessed in 182 children and adolescents (6-18 years of age) with diabetes and 160 nondiabetic control subjects. RESULTS: There were no differences between case and control subjects with respect to dental caries. Children with diabetes had significantly higher plaque and gingival inflammation levels compared with control subjects. The number of teeth with evidence of attachment loss (the hallmark of periodontal disease) was significantly greater in children with diabetes (5.79 +/- 5.34 vs. 1.53 +/- 3.05 in control subjects, unadjusted P < 0.001). When controlling for age, sex, ethnicity, gingival bleeding, and frequency of dental visits, diabetes remained a highly significant correlate of periodontitis, especially in the 12- to 18-year-old subgroup. In the case group, BMI was significantly correlated with destruction of connective tissue attachment and bone, but duration of diabetes and mean HbA(1c) were not. CONCLUSIONS: Our findings suggest that periodontal destruction can start very early in life in diabetes and becomes more prominent as children become adolescents. Programs designed to promote periodontal disease prevention and treatment should be provided to young patients with diabetes.

Adolescent↗

PubMed2006

[Protective effects of ginkgo leaf extracts on neurons in spinal cord after ischemia-reperfusion injury in rabbits].

OBJECTIVE: To observe the protective effects of ginkgo leaf extracts on spinal cord after ischemia-reperfusion (IR) injury in rabbits and to find out its possible mechanism. METHODS: Twenty-seven New Zealand white rabbits were randomly divided into three groups, which were sham-operation group, untreated group and ginkgo leaf extracts-treated group. The locomotor scores of hindlimbs in rabbits after 24 and 48 h of reperfusion were evaluated, and the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in ischemia spinal cord were examined. The apoptotic index (AI) of neurons in spinal cord was detected by terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) method. The expressions of Bcl-2 and Bax proteins were examined by streptavidin-biotin peroxidase method. RESULTS: The locomotor scores of hindlimbs in rabbits after 24 and 48 h of reperfusion in the ginkgo leaf extracts-treated group were obviously elevated as compared with those in the untreated group (P<0.05). The activity of SOD was higher and the level of MDA was lower in ischemia spinal cord in the ginkgo leaf extracts-treated group than those in the untreated group (P<0.01). The decreased neuron AI and the expressions of up-regulated Bcl-2 protein and down-regulated Bax protein were also observed in the ginkgo leaf extracts-treated group. CONCLUSION: The protective effects of the ginkgo leaf extracts against spinal cord injury induced by IR may be related to scavenging oxygen free radicals, reducing lipid peroxidation injury and inhibiting apoptosis.

Animals↗

PubMed2006

Effects of Ginkgo biloba extract on lipid peroxidation and apoptosis after spinal cord ischemia/reperfusion in rabbits.

OBJECTIVE: To study the effects of Ginkgo biloba extract (GBE) on lipid peroxidation and apoptosis after spinal cord ischemia/reperfusion (I/R) in rabbits. METHODS: Spinal cord I/R injury model was established according to the description of Erten et al. A total of 27 New Zealand white rabbits were divided into three groups randomly: a sham group (9 rabbits treated with sham operation but without aortic occlusion), a model group (9 rabbits treated with aortic occlusion and volume-matched saline), and a GBE group (9 rabbits treated with aortic occlusion and Ginaton (100 mg/kg) injected 30 minutes before aortic clamping and at the onset of reperfusion). The neurological outcomes were evaluated at 24 and 48 hours after reperfusion, respectively. The spinal cord malondialdehyde (MDA) level, superoxide dismutase (SOD) were then detected. Neural cell apoptosis was determined by terminal deoxynucleotidyl t-ransferase (TdT)-mediated dUTP-fluorescence nick end labeling (TUNEL) method and the expression of bcl-2 and bax were examined histologically in the spinal cord with immunohistochemistry. RESULTS: I/R produced a significant decrease in neurological scoring. The motor scores of the GBE group were significantly higher than those of the model group at 24 and 48 hours after reperfusion (P<0.05). Compared with the model group, GBE ameliorated the down-regulation of SOD and produced a significant reduction of the MDA level (P<0.01). The positive cells for TUNEL in the model group were much more than those of the GBE group (P<0.01). The bcl-2 was up-regulated after I/R, especially in the GBE group (P<0.01). The up-regulation of bax was greatly diminished by GBE (P<0.01). CONCLUSIONS: GBE has protective effects against spinal cord I/R injury, and the mechanism may be that it can scavenge oxygen free radicals and inhibit the apoptosis of neural cells.

Animals↗

PubMed2006

Effects of buyang huanwu decoction on apoptosis of nervous cells and expressions of Bcl-2 and bax in the spinal cord of ischemia-reperfusion injury in rabbits.

OBJECTIVE: To study the effect of buyang huanwu decoction ([Chinese characters: see text] BYHWD) on spinal ischemia-reperfusion injury and explore the possible mechanism involved. METHOD: 27 model rabbits with ischemia-reperfusion injury were randomly divided into a sham operation group, a model group and a BYHWD-pre-treated group. 24 and 48 hours after the ischemia-reperfusion injury, the motor functions of hind limbs were observed, the expressions of apoptosis-related proteins bcl-2 and Bax in the spinal tissue were investigated with the immunohistochemical methods and apoptosis of nervous cells with TUNEL straining; and the malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in the spinal cord were then determined. RESULTS: BYHWD can improve significantly the motor function of hind limbs, increase SOD activity and decrease the level of MDA, up-regulate expression of Bcl-2 and down-regulated expression of Bax, and depress apoptosis of nervous cells in the spinal cord caused by the ischemia reperfusion in the rabbits. CONCLUSION: BYHWD has a protective action on the spinal ischemia-reperfusion injury, and the mechanisms may be related to the decrease of lipid peroxidation and inhibition of apoptosis of nervous cells.

Animals↗

PubMed2005

The feasibility of monitoring NF-kappaB associated cytokines: TNF-alpha, IL-1alpha, IL-6, and IL-8 in whole saliva for the malignant transformation of oral lichen planus.

Previous investigations have demonstrated that immune activation and chronic inflammation may be one of the causes of oncogenesis. A previous study from our lab has shown significant increases of NF-kappaB dependent cytokines, TNF-alpha, IL-1alpha, IL-6, and IL-8 in different oral fluids from oral lichen planus (OLP) patients. The aim of this analysis was to explore the potential of detecting these cytokines in whole unstimulated saliva (WUS) in monitoring the malignant transformation of OLP. Thirteen patients with OLP (with epithelial dysplasia), 13 cases with oral squamous cell carcinoma (OSCC), and 13 age-sex matched controls were enrolled in the study. The WUS samples were collected and the level of TNF-alpha, IL-1alpha, IL-6, and IL-8 in WUS was determined by ELISA. In moderate and severe dysplasia, the level of each cytokine was significantly higher than in control. In moderate dysplasia, TNF-alpha and IL-1alpha were significantly increased at a level without difference from OSCC, but IL-6 and IL-8 was detected at a concentration significantly lower than OSCC. In severe dysplasia, the level of TNF-alpha was also not significantly different from that of OSCC, and the level of IL-1alpha, IL-6, and IL-8 was still significantly lower than that of OSCC. The level of four cytokines between smokers and non-smokers in each group did not show a significant difference. These results indicate that the change of NF-kappaB dependent cytokines in WUS may in part reflect the malignant transformation of OLP and the analysis of these cytokines and may provide a useful, non-invasive surrogate endpoint for monitoring malignant transformation as well as the therapeutic response of OLP. This is the first in vivo study utilizing saliva to confirm preclinical data that NF-kappaB is upregulated in oral carcinogenesis.

Cell Transformation, Neoplastic↗

PubMed2005

Expression of DNA repair enzyme hMTH1 mRNA and protein in hepatocellular carcinoma.

To study the expression of DNA repair enzyme hMTH1 mRNA and protein in hepatocellular carcinoma (HCC) tissues, tissues adjacent to the cancers, normal liver cells and hepatoma cell lines, and to investigate their function in the progress of HCC, semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) was employed to examine the expression of hMTH1 mRNA in matched HCC tissues (HT)/surrounding tissues (HST) of HCC, normal liver cell L02 and hepatoma cell lines SMMC7721, HepG2. hMTH1 protein was detected in corresponding HT as well as their HST by immunohistochemistry. Our results showed that the expression level of hMTH1 mRNA in HT was higher than that in HST (t = 2.424, P < 0.05). The expression level of hMTH1 mRNA in two hepatoma cell lines was higher than that in normal liver cell line (F = 6.810, P < 0.01). The expression of hMTH1 mRNA in SMMC7721 was similar to that in HepG2. hMTH1 protein was 88.2% (15 of 17) positive in HT and 82.4% (14 of 17) in HST. The protein level of hMTH1 in HT was correspondingly higher than in their HST (t = 2.18, P < 0.05). It is concluded that hMTH1 mRNA and protein were over-expressed in HCC and hepatoma cell lines. It may be one of the key events during the carcinogenesis, progression of HCC and may promote the malignant growth. These results suggest that hMTH1 plays a role in HCC and may be a candidate marker for the diagnosis of HCC.

Antimutagenic Agents↗

PubMed2005

A comparison of the pro-inflammatory, NF-kappaB-dependent cytokines: TNF-alpha, IL-1-alpha, IL-6, and IL-8 in different oral fluids from oral lichen planus patients.

To explore the feasibility of detection of the level of NF-kappaB-dependent cytokines in oral fluids from patient with oral lichen planus (OLP) for clinical application, 13 OLP subjects were enrolled in the study as were 13 age-sex-matched controls. In each subject, the whole unstimulated saliva (WUS), mixture of saliva and isotonic saline oral rinse (Saliva-NaCl), and lesion tissue transudates (TT) were collected by standard techniques. The level of cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in three types of oral fluids was determined by ELISA. In the three types of oral fluids, a significantly higher level of these cytokines was detected in OLP patients than in normal controls. These results indicate that NF-kappaB-dependent inflammatory cytokines may be detected at increased levels in certain oral fluids which may have diagnostic and prognostic potential for monitoring disease activity and making therapeutic decisions in patients with OLP.

Biomarkers↗

PubMed2005

[Effects of applying L-methionine, L-phenylalanine and L-tryptophan on Zea mays growth and its nutrient uptake].

A pot experiment was conducted to evaluate the effects of applying L-methionine (L-MET), L-phenylalanine (LPHE) and L-tryptophan (L-TRP) on the growth of Zea mays and its nutrient uptake, and to determine the optimal application rate of them. The results showed that L-MET, L-PHE and L-TRP could improve the shoot height, shoot and root dry weights, root activity, nitrate reductase and hydrogen peroxidase activities, and N, P, K and Zn uptake of corn. The optimal application rate of L-MET, L- PHE and L-TRP was 0.0185 - 0.185 mg x kg)(-1) soil, 0.2 mg x kg(-1) soil, and 0.03 - 0.3 mg x kg(-1) soil, respectively, and L-PHE and L-TRP were superior to L-MET.

Fertilizers↗

PubMed2004

Large-Scale, solution-phase growth of single-crystalline SnO2 nanorods.

Small-diameter (<5 nm), single-crystalline SnO2 nanorods were synthesized in solution with a mean length of 17 +/- 4 nm (mean aspect ratio of 4:1) with the [001] direction along the major axis. Two characteristic peaks at 576 and 356 cm-1 in the Raman spectrum further confirmed the small crystal size. The SnO2 nanorods exhibit a red emission at 580 nm.

Journal Article↗