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Biomedical subjects

J Cao

Publications and source records attributed to J Cao.

At least 145 records · Page 8Linked to original sources
PubMed2000

[Impact of glutamine of gut permeability and clinical prognosis on the aging patients undergoing gastric-intestinal operation].

OBJECTIVE: To evaluate the impact of parenteral nutrition supplemented glutamine on aging patients undergoing gastric-intestinal operation. METHODS: 30 patients above 60 years old undergoing gastric-intestinal operation, a randomized double-blind protocol was designed, divided into two groups, received impact isocaloric parenteral nutrition. The study group received alanyl-glutamine [0.5 g/(kg.d)]. To observe plasma amino acids profile, nitrogen balance, intestinal permeability and clinical prognosis, examine clinical chemistry variables and observe the adverse reactions in order to find out its safety. RESULTS: The patients in both groups were comparable prior to the operation. The plasma glutamine level of study group is higher than the control group, it's cumulative nitrogen balance values were prior to the control group, L/M ratio was lower than the control group. The complications related to infection was observed more in the control group. No adverse reaction was observed in both groups. CONCLUSIONS: Ala-Gln-supplemented PN improved nitrogen balance and maintained intestinal permeability, reduced complications.

Aged↗
PubMed2000

[Effect of low dose gossypol treatment on male sperm nuclear basic protein].

OBJECTIVE: Study on human sperm nuclear basic proteins after low dose of gossypol treatment. METHODS: Twenty-three men with normal fertility were divided into two groups. The experimental group included 15 men which were treated daily with gossypol (15 mg/d for 12 weeks and treated with 10 mg/d for 32 weeks continuously), 8 men were used in the control group. Semen was collected at 1, 4, 8, 12, 16, 24, 36 and 44 weeks after gossypol treatment and 10 weeks after stopping treatment. Total nuclear basic protein (TNBP) was extracted and TH/TP, HP1/(HP2+HP3) ratios were determined by scanning microdensitometry following electrophoresis of TNBP in polyacrylamide gels. RESULTS: The TH/TP ratio of control and the gossypol treated group were 0.17 +/- 0.07 and 0.63 +/- 0.79(P < 0.05); The HP1/(HP2+HP3) ratio of control and gossypol treated group were 1.05 +/- 0.21 and 1.47 +/- 0.18 (P < 0.01). These two parameters were returned to normal after 10 weeks of stopping gossypol treatment. CONCLUSIONS: The interruption of histone-to-protamine replacement reaction (HPRR) and alteration of nuclear basic proteins induced by low dose gossypol treatment might lead to infertility. Changes of HPRR and nuclear basic protein were reversible after stopping gossypol treatment.

Adult↗
PubMed2000

[Detection of high risk human papillomavirus DNA in oral squamous cell carcinoma].

OBJECTIVE: To ascertain the prevalence of human papillomavirus(HPV) DNA in oral squamous cell carcinomas(OSCCs) and normal oral mucosa and to correlate the virologic data with other factors obtained from patients' records. METHODS: 113 paraffin embedded tissue blocks including 73 OSCCs and 40 normal oral mucosa were studied by polymerase chain reaction (PCR) for HPV type 16 and 18 DNA. Medical records of patients were reviewed to obtained the following factors: age, sex, tobacco and alcohol usage, site of tumor, histologic grade and clinical stage. RESULTS: 74%(54/73) of OSCCs and 55%(22/40) of normal oral mucosa were HPV 16/18 DNA positive. The presence of HPV DNA showed significant difference between OSCCs and normal oral mucosa (P=0.040). Statistical analysis indicated that age (60</=years) and sex (male) were associated with the presence of HPV16/18 DNA in the tumor. There were no significant association between HPV presence and other factors, include tobacco and alcohol usage, site of tumor, histologic grade and clinical stage. CONCLUSION: High risk HPV genotypes have a significant association with oral squamous cell carcinoma. It is a co-factor in oral carcinogenesis, particularly in male patients and patients under the sixth decade. HPV infection in the oral mucosa is common. HPV is not the single etiological factor responsible for human oral neoplasia.

English Abstract↗
PubMed1999

Salt effects in capillary zone electrophoresis. IV. Resolution versus time and the effect of potassium phosphate and its concentration in the high ionic strength separation of sulphonamides.

The effects of potassium phosphate buffer and its concentration upon the capillary zone electrophoretic separation of 23 sulphonamides and a neutral marker were examined at pH 7. The resolution between the pairs was improved with the increased concentration of the buffer from 65 mM to 174 mM. Nineteen sulphonamides, a hydrolysis product and several unidentified minor components were baseline resolved in both 101 and 138 mM phosphate buffers. In 174 mM buffer all 21 ionised sulphonamides and the other compounds were separated. A simple relationship between the resolution of analyte pairs (Rs) and the square root of the mean analysis time for the pair (square root of tapp) was derived, but few of the pairs displayed this behaviour. For the majority of pairs of compounds, Joule heating appeared to cause a maximum in the Rs versus square root of tapp relationship, while non-ideality and shifts in ionisation with increasing salt concentration appeared dominant in other cases.

Buffers↗
PubMed1999

Astilbin selectively induces dysfunction of liver-infiltrating cells--novel protection from liver damage.

The present study aimed to examine the effect of astilbin, a flavanoid, on liver injury. When administered during the effector but not induction phase, astilbin significantly decreased the liver injury induced by delayed-type hypersensitivity to picryl chloride in mice. The pretreatment of nonparenchymal cells but not hepatocytes with astilbin in vitro caused a concentration- and time-dependent inhibition against the damage. Nonparenchymal cells isolated from astilbin-administered mice also showed a significant incompetence of hepatotoxicity, correlated with the inhibition of serum transaminase elevation. However, astilbin did not protect from CCl4-induced liver damage. Furthermore, the flavanoid markedly promoted the apoptosis of nonparenchymal cells from liver-injured mice, whereas did not influence those from naive mice. These results suggest that astilbin provides improvement against liver injury through a selective dysfunction of liver-infiltrating cells rather than by protecting the hepatocyte membrane. Such characteristics will be of significance to pave a new way for treating immunologically related liver diseases and for developing new drugs.

Animals↗
PubMed1999

Ultrafast electron diffraction and direct observation of transient structures in a chemical reaction.

Ultrafast electron diffraction is a unique method for the studies of structural changes of complex molecular systems. In this contribution, we report direct ultrafast electron diffraction study of the evolution of short-lived intermediates in the course of a chemical change. Specifically, we observe the transient intermediate in the elimination reaction of 1,2-diiodotetrafluoroethane (C2F4I2) to produce the corresponding ethylene derivative by the breakage of two carbon-iodine, C---I, bonds. The evolution of the ground-state intermediate (C2F4I radical) is directly revealed in the population change of a single chemical bond, namely the second C---I bond. The elimination of two iodine atoms was shown to be nonconcerted, with reaction time of the second C---I bond breakage being 17 +/- 2 ps. The structure of the short-lived C2F4I radical is more favorable to the classical radical structure than to the bridged radical structure. This leap in our ability to record structural changes on the ps and shorter time scales bodes well for many future applications in complex molecular systems.

Chemical Phenomena↗
PubMed1999

Synergistic effect of copper and lead uptake by fish.

Paracheirodon innesi was exposed (simultaneously or sequentially) to copper and lead in varying concentrations in a synthetic water solution. Metal accumulations in fish gills and the fish (without gills) were measured at the end of the exposure period. Results of the exposure experiment indicated that lead seems to facilitate the uptake of copper and vice versa when the exposure process is simultaneous. In the case of sequential exposure first to copper for 7 days then to lead for 20 days, lead accumulations in the fish and the gills were enhanced by copper, indicating a possible alteration of the physiological absorption process. The synergistic effects observed during either simultaneous or sequential exposure experiments can be described using logistic equations.

Animals↗
PubMed1999

Effects of several drugs on the liver injury induced by delayed-type hypersensitivity to picryl chloride by regulating suppressor or helper T cells.

The effects of histamine, cimetidine, and diphenhydramine on picryl chloride (PCl)-induced ear contact sensitivity, as well as liver injury, were examined in mice. Histamine was found to produce less response in mice to PCl. In contrast, cimetidine, a selective antagonist of histamine type 2 receptor, significantly enhanced the response, while diphenhydramine, a selective antagonist of histamine type 1 receptor showed no effect. The pre-treatment of 2,4, 6-trinitrobenzene sulphonic acid (TNBS) significantly caused a tolerance to the formation of the liver injury induced by delayed-type hypersensitivity (DTH) to PCl. Against the tolerance, the single intravenous administration of 150 mg kg-1 cyclophosphamide (Cy) at 3 days before the TNBS-treatment recovered the response and induced a remarkable elevation of serum transaminases. On the other hand, cyclosporin A protected the liver injury. These observations revealed that the development of acute PCl-DTH liver injury was regulated by the functional state of suppressor and helper T cells.

Animals↗
PubMed1999

Normal changes in spinal bone mineral density in a Chinese population: assessment by quantitative computed tomography and dual-energy X-ray absorptiometry.

This study was designed to determine age- and gender-based normative values for spinal bone mineral density (BMD) in a Chinese population. In addition, we compared our data with those of other countries and populations. Four hundred and forty-three healthy Chinese subjects, aged 10-79 years (189 males, mean age 46.9 years; 254 females, mean age 45.7 years) were recruited for BMD assessment. BMD was measured by quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA), including posteroanterior DXA (PA-DXA), lateral DXA (L-DXA) and midlateral DXA (mL-DXA). For both genders, BMD values peaked in the 10-19 year age group when measured by QCT, and in the 30-39 year age group when measured by PA-DXA. BMD values decreased with age after reaching peak bone density in males and females for all measurements, except for PA-DXA in males. Male BMD values by DXA tended to increase beginning with the 60-69 age group through the 70-79 age group whether by PA-DXA, or L-DXA and mL-DXA. However, male QCT data showed stable BMD values among these two older groups. Comparative results showed female QCT data were higher in the 20-39 age group and lower after the 40-49 age group compared with American females. The peak BMD value by PA-DXA in Chinese females was reached in the same age group as American and European females and was similar in magnitude (p > 0.05). However, the peak BMD value for Chinese females was reached earlier and was significantly higher than that observed in Japanese females (p < 0.001). We conclude that the age group in which the peak BMD values are reached is different depending on the technique used, as is the calculated age-related rate of bone loss. It can be speculated that such differences reflect different timing for bone maturation in cancellous and cortical bone.

Absorptiometry, Photon↗
PubMed1999

Uptake of particulate lead via the gills of fish (Carassius auratus).

Carassius auratus were exposed to mixtures of constant free lead (0. 1 mg/L) and particulate lead (adsorbed on gibbsite particles) at varied concentrations (0, 0.4, 0.8, 1.2, 2.0, and 3.0 mg/L). The concentrations of lead and aluminum in the gills and intestines of the fish were determined after exposure. The gills were examined (after the exposure) with a light microscope for any particles adhering to the surface. The examination results revealed that lead accumulations on the gills increased with increased particulate lead concentrations in the ambient water (under conditions of a constant level of free lead), indicating the bioavailability of lead via the gills. Gibbsite particles were also observed on the gill surface after exposure. The ratio of lead and aluminum in the gills was much higher than that in the particles. Our results suggest that there was a two-step process involved in the uptake of particulate lead by fish gills: (1) adherence of the particles on the gill surface where mucus was attached; and (2) desorption of lead from the particles under conditions of the gill microenvironment.

Animals↗
PubMed1999

Reducing degradation of azo dye by zero-valent iron in aqueous solution

The reducing degradation kinetics of five azo dyes, Acid orange II, Acid orange IV, Acid orange GG, Acid red 3B and Orange I, by zero-valent iron powder in aqueous solution were studied. It showed that the degradation is a two-step reaction, with the first step being reversible. Solution acidity and iron surface area are the factors greatly influencing the degradation rates, and with increasing of acidity and iron surface area, the degradation rates increase.

Journal Article↗
PubMed1999

Prediction of fish bioconcentration factors of nonpolar organic pollutants based on molecular connectivity indices.

The relationship between bioconcentration factors and molecular connectivity indices was investigated. A regression model was developed using 80 measured BCFs of nonpolar organic pollutants. The five topological parameters used were 1 chi, 2 chi, 3 chi c, 0 chi v and 2 chi v. Modified jackknife tests were applied to examine the robustness of the model by repeatedly removing a set of or a class of compounds from the database. The model was compared with one using Kow as an independent parameter. The mean absolute errors for the 80 compounds studied were 0.288 and 0.302 log-unit for the two models, respectively.

Animals↗
PubMed1999

Leaching kinetics of water soluble organic carbon (WSOC) from upland soil.

The kinetics of the leaching process of Water Soluble Organic Carbon (WSOC) from an upland soil were studied in a column leaching experiment. The pattern of the leaching curve indicated multiphasic release kinetics. A conceptual model was proposed to divide capillary and gravitational pores. The translocation of organic carbon in soil during leaching occurs in four sequential steps. 1) degradation of insoluble organic carbon to form WSOC; 2) desorption into capillary pore water; 3) diffusion towards gravitation pore water; and 4) leaching by convection flow. The overall kinetics of the leaching process can be depicted using an equation with three additive terms for degradation, desorption/diffusion, and convection, respectively.

Carbon↗
PubMed1999

Recognition of an epitope of a breast cancer antigen by human antibody.

A novel tumor-associated peptide epitope KASIFLK expressed preferentially by breast cancer cells was identified using an IgG antibody from a breast cancer patient. A cDNA library from a MCF-7 breast cancer cell line was screened to isolate three cDNA clones that were immunoreactive with this antibody. KASIFLK was located in clones 27 and 40, both of which were identical to the cDNA and protein sequence of retinoblastoma binding protein 1 (RBP1, 250-256). An affinity-purified IgG antibody against the peptide epitope was completely absorbed by cytoplasmic extracts of MCF-7 cells. Immunohistochemical staining using this antibody revealed the antigen in MCF-7 cells and in 12 of 15 primary breast cancer tissues and 3 of 34 other cancer tissues, but in none of 6 normal breast tissues. Anti-KASIFLK antibody titers were significantly higher in sera of 55 breast cancer patients than in sera from 30 normal healthy donors (P>0.001). These results suggest that KASIFLK or its cross-reactive epitope is a breast cancer antigen and is immunogenic in humans.

Amino Acid Sequence↗
PubMed1999

The receptor for the orexigenic peptide melanin-concentrating hormone is a G-protein-coupled receptor.

Gene-knockout studies of melanin-concentrating hormone (MCH) and its effect on feeding and energy balance have firmly established MCH as an orexigenic (appetite-stimulating) peptide hormone. Here we identify MCH as the ligand for the orphan receptor SLC-1. The rat SLC-1 is activated by nanomolar concentrations of MCH and is coupled to the G protein G alpha i/o. The pattern of SLC-1 messenger RNA expression coincides with the distribution of MCH-containing nerve terminals and is consistent with the known central effects of MCH. Our identification of an MCH receptor could have implications for the development of new anti-obesity therapies.

Animals↗
PubMed1999

Cytotoxic T lymphocytes that recognize decameric peptide sequences of retinoblastoma binding protein 1 (RBP-1) associated with human breast cancer.

Retinoblastoma binding protein 1 (RBP-1) is a 143-kDa nuclear phosphoprotein that promotes cell growth by inhibiting the product of retinoblastoma tumour suppressor gene (pRB). We recently found that RBP-1 contains KASIFLK, a heptameric peptide (250-256) recognized by human antibodies and overexpressed by breast cancer cells. In the present study, we demonstrate that human T-cells stimulated with RBP-1 decameric peptides containing KASIFLK can kill human breast cancer cells. These decamers, GLQKASIFLK (247-256) and KASIFLKTRV (250-259), have anchor motifs for both HLA-A2 and HLA-A3. Peripheral blood lymphocytes from 41 normal donors were stimulated by these peptides in culture media containing 15 IU ml(-1) interleukin-2, 25 IU ml(-1) interleukin-7 and 500 IU ml(-1) granulocyte-macrophage colony-stimulating factor. Cytotoxic activity of the T-cells was assessed against autologous B lymphoblastoid cells pulsed with each peptide. Stimulation by GLQKASIFLK generated specific cytotoxic T lymphocyte (CTL) lines from HLA-A2, A3 donors, HLA-A2 donors and HLA-A3 donors. Stimulation with KASIFLKTRV generated specific CTL lines from HLA-A2 donors. No HLA-A2-, A3 CTL line showed specific cytotoxicity against these target cells. These CTL lines were also cytotoxic against HLA-A2 and HLA-A3 breast cancer cells but not against normal fibroblastoid cell lines, normal epidermal cell lines, or a melanoma cell line. RBP-1 peptide antigens may be of clinical significance as a potential peptide vaccine against human breast cancer.

Amino Acid Sequence↗
PubMed1999

A new flavanone isolated from rhizoma smilacis glabrae and the structural requirements of its derivatives for preventing immunological hepatocyte damage.

From the rhizome of Smilax glabra Roxb., a new flavanone was isolated and named as smitilbin (1), together with 6 known compounds, engeletin (2), astilbin (3), dihydroquercetin (4), eurryphin (5), resveratrol (6), and 5-O-caffeoylshikimic acid (7). These compounds were applied to the assay of liver nonparenchymal cells (NPC) against hepatocytes (HC) isolated from mice with an immunological liver injury. Against the NPC-caused elevation of ALT (alanine transminase) in culture supernatant from HC, the pretreatment of NPC with flavanoids (1-3) dose-dependently blocked the ALT release while 4, the aglycone of 3, did not. The chromone 5 showed a much stronger inhibition. Compound 6 also showed the activity. However, 1-7 did not show any suppression of NPC or CCl4-induced ALT release when they were used to pretreat HC. These results suggest that compounds 1-3, 5, and 6 could protect the hepatocyte damage from NPC through selectively producing the dysfunction of NPC with an essential requirement of rhamnose, and the chromone part in their structures may be critical for exhibiting the activity rather than through protecting the hepatocyte membranes.

Animals↗