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Biomedical subjects

R Guo

Publications and source records attributed to R Guo.

At least 127 records · Page 7Linked to original sources
PubMed1996

Relationship between high incidence of adverse dapsone reactions and slow acetylate phenotype or low plasma/lymphocyte glutathione level.

OBJECTIVE: To investigate the relationship between high incidence of adverse dapsone reactions in acquired immunodeficiency syndrome (AIDS) patients and slow acetylate phenotype or low plasma/lymphocyte glutathione level of these patients. METHODS: Twenty-one cases of advanced AIDS patients (CD4 < 200/microliter) were involved in this study, all Europeans except one black, were acetylate phenotyped via analysis of caffeine metabolites, named 5-Acetylamino-6-formylamino-3-methyluracil, 1-Methylxanthine and 5-Acetylamino-6-amino-3-methyluracil, in human urine collected 2 hours after a cup of caffeine-spiked coffee and their plasma/lymphocyte glutathione concentrations were determined, by high performance liquid chromatographic method. RESULTS: Of the 21 AIDS patients, 15 are slow acetylators, accounting for 74.8%. One of 6 rapid acetylators has adverse dapsone reactions, acounting for 17%, compared with 46% for slow acetylators (7/15). The concentrations of glutathione in plasma/lymphocyte (6.97 +/- 0.95 mumol and 28.75 +/- 2.78 nmol/mg protein) in AIDS patients with adverse dapsone reactions are significantly lower than those (10.90 +/- 1.45 mumol and 32.15 +/- 2.21 nmol/mg protein) of AIDS patients without adverse dapsone reactions, and also than those (11.85 +/- 1.83 mumol and 33.76 +/- 2.32 nmol/mg protein) of health controls. CONCLUSIONS: Slow acetylators, which lead to accumulation of toxic dapsone metabolites and those subjects who are lower in glutathione level in plasma/lymphocyte because of certain kind of diseases as advanced AIDS are risk population of adverse dapsone reactions. Routinely determining human acetylate phenotype status might be helpful in adjusting and modifying dapsone dosage regimen.

Acetylation↗
PubMed1996

[Expressing poliovirus (type I) and hepatitis A virus antigens by recombinant vaccinia virus].

A recombinant vaccinia virus expressing PV-I and HAV antigens was constructed. Dot blot and Southern blot confirmed that the recombinant virus genome contained PV-I cDNA and HAV cDNA chimeric fragment. The result of IF indicated that PV-I antigen and HAV antigen were successfully expressed in the mammalian cells infected with the recombinant virus. The expressed PV-I and HAV antigen showed one band which had both PV-I and HAV antigenicities in Western blot. The band was about 120,000(MW). When guinea pigs were immunized with the recombinant virus, PV-I and HAV neutralizing antibodies were induced. The result indicated that the recombinant virus constructed here had bi-valence of PV-I and HAV antigen as well as PV-I and HAV immunogenecities.

Animals↗
PubMed1996

[Influence of processing on quercetin content in flos Sophorae immaturus].

The HPLC method was applied to determine the quercetin content in Flos Sophorae Immaturus. The technology for processing Flos Sophorae Immaturus was selected based on orthogonal experiment design. The result has shown that the better technology is to bake Flos Sophorae Immaturus for 11 min at the temperature of 180 degrees C.

Chromatography, High Pressure Liquid↗
PubMed1995

Is the pulmonary venous-transmitral A-wave duration difference altered by age and hypertension?

We have demonstrated that the pulmonary venous and transmitral atrial duration, and the difference between the 2 are independent of age and not influenced by hypertension, but have a high interobserver variability and range of variability. Enthusiasm for this parameter with the currently available recording techniques must be tempered by the high variability in this measurement.

Adult↗
PubMed1995

The treatment of pain in bone metastasis of cancer with the analgesic decoction of cancer and the acupoint therapeutic apparatus.

The pain in 286 cases of bone metastasis of cancer was treated with an analgesic decoction of herbal drugs in combination with the Acupoint Therapeutic Apparatus that generated low frequency electric impulses into the acupoints. This series of patients comprised 104 cases of medium pain and 182 cases of severe pain, which was practically or completely relieved in 17 or 29 minutes respectively after the treatment; the total effective rate was 74.2% for 212 cases, and the duration of analgesic effect lasted 2.7 hours to 5.2 hours, averaging 3.6 hours. The cases that needed considerable dosages of analgesic tablets or sedatives markedly reduced their requests of such drugs. Determination of bone marrow stem cells indicated that the herbal treatment produced effects of promoting and protecting the stem cells. The rate of lymphocyte transformation was 45-76% before the treatment and rose to 57-96% after the treatment, demonstrating an increase of 15.2%, which was statistically significant (P < 0.001). The analgesic effect of the decoction was not correlated to the age and sex of the patients or the variety of cancer, except that it was not effective for uterine carcinoma. The main side effects included nausea, vomiting, somnolence, and numbness of the tongue.

Acupuncture Therapy↗
PubMed1995

[The reversing effect of HPV-16 E6E7 gene antisense plasmid on the HPV-16 positive human cervical carcinoma cells].

Antisense reconstruct, p16as E6E7Neo, harboring HPV-16E6E7 gene of which the expression is regulatable by dexamethasone was constructed. Calcium phosphate mediated transfection was employed to transduce this antisense reconstruct into HPV-16 positive CasKi cell line and HPV negative C-33A cell line (both derived from human cervical carcinoma) respectively. After dexamethasone was added into the culture medium to induce the expression of E6E7 antisense gene, the malignity of CasKi cells were reversed, while the growth characteristics and malignity of C-33A cells were unchanged. The results show that the reversing effect on CasKi cell is specific and mediated by inhibition of expression of E6E7 gene. It also demonstrated a more profound pathogenic role of HPV-16 E6E7 gene in the tumorogenesis of cervical carcinoma and provides a possibility for gene therapy of this tumor.

Animals↗
PubMed1994

Synthesis and characterization of a biotinylated organophosphorus ester for detection and affinity purification of a brain serine esterase: neuropathy target esterase.

We have synthesized a novel stable precursor, saligenin phosphorotrichloridate, which, on reaction with N-monobiotinyldiamines, generates a series of biotinylated covalent inhibitors of serine esterases. A homologue designated S9B [1-(saligenin cyclic phospho)-9-biotinyldiaminononane] was selected to allow detection and rapid isolation of neuropathy target esterase (NTE). This enzyme is the primary target site for those organophosphorus esters (OPs) which cause delayed neuropathy. NTE comprises about 0.03% of the total protein in brain microsomal fractions and has resisted purification attempts over many years. S9B is a potent progressive inhibitor of NTE esteratic activity (second-order rate constant 1.4 x 10(7) M-1.min-1). Incubation of S9B with brain microsomes led to specific covalent labelling of NTE as determined by detection of a biotinylated 155 kDa polypeptide on Western blots. Specificity of S9B labelling was further demonstrated by inhibition with the neuropathic OP mipafox. Biotinyl-NTE in SDS-solubilized S9B-labelled microsomes was adsorbed on to avidin-Sepharose and subsequently eluted, yielding a fraction enriched approx. 1000-fold in NTE by a single step with recoveries of 30%. Essentially pure NTE was obtained after separation from two endogenous biotinylated polypeptides (120 and 70 kDa) in avidin-Sepharose eluates by preparative SDS/PAGE. Other biotinylated saligenin phosphoramidates derived from the same precursor may be useful for detection and isolation of other serine esterases and proteinases.

Animals↗
PubMed1994

Transesophageal echocardiographic assessment of the effects of age, gender, and hypertension on thoracic aortic wall size, thickness, and stiffness.

Aging is associated with progressive arterial stiffening and widening of the pulse pressure, resulting in a high prevalence of systolic hypertension. The contribution of increased aortic thickness to this process and to essential hypertension has been poorly characterized. With transesophageal echocardiography, aortic thickness and diameter can be measured. Thus, the influence of aging, gender, and hypertension on the geometry and stiffness of the descending thoracic aorta in humans can be determined in vivo. In 83 patients undergoing transesophageal echocardiography for clinical indications, recordings of the descending thoracic aorta were made. There were 53 normotensive subjects (33 men and 20 women, mean age 46 years, range 14 to 79 years) and 25 hypertensive subjects (8 men and 17 women, mean age 67 years, range 50 to 80 years). Measurements of diastolic and systolic aortic thickness and aortic diameter were made, and three measures of the elastic properties of the aorta were calculated: (1) Peterson's elastic modulus, (2) Young's modulus, and (3) the stiffness index (beta). Aortic thickness averaged 1.1 +/- 0.1 mm in both normotensive men and women. Normotensive women had a significantly greater thickness/diameter ratio than men (0.06 +/- 0.01 vs 0.05 +/- 0.01, p < 0.01), but there were no differences in stiffness between men and women. Age was highly positively correlated with thickness (r = 0.74, p < 0.001), diameter (r = 0.67, p < 0.001), beta (r = 0.79, p < 0.001), Peterson's modulus (r = 0.78, p < 0.001), and Young's modulus (r = 0.81, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[The investigation on drug resistance to N. gonorrhoeae in Benxi district].

The sensitivity of 95 strains of N. gonorrhoeae to antibiotics was determined. In 1990, among 18 strains of N. gonorrhoeae, 7 (38.90%) were resistant to Penicillin G, 3 (16.66%) to Gentamicin, 8 (44.44%) Kanamycin, 8 (44.44%) Midecamycin. In 1992, among 77 strains of N. gonorrhoeae, 61 (79.22%) were resistant to Penicillin G, 38 (49.35%) to Gentamicin, 62 (80.52%) to Kanamycin, 54 (70.13%) to Midecamycin, 56 (72.72%) to Ampicillin 60 (77.92%) to Erythromycin, 22 (28.57%) to Cefazolin, 18 (23.37%) to Cefotaxime. The results showed that Cefazolin and Cefotaxime were the most effective antibiotics, Gentamicin was the next.

Adult↗
PubMed1993

[Study on compound levonorgestrel microspheres].

Levonorgestrel (LNG) and estradiol (E2) were mixed in the ratio of 5:2 by weight. Compound LNG gelatin-microspheres were prepared by phase-separation method, natural biodegradable gelatin being used as the core material. The experimental conditions were optimized, the mean diameter of the microspheres obtained being 10-40 microns, and the rate of encapsulation 65-75%. Storage observations and acceleration tests of the compound LNG gelatin-microsphere injection prepared showed that the microspheres have good stability. The thermal degradation activation energy of the injection was determined to be 134.4 kJ/mol, based on differential scanning colorimetry (DSC). T1/2 values for dissolution in vitro of LNG and E2 from the compound LNG gelatin-microsphere injection and from the unencapsulated injection showed significant difference (P < 0.01), indicating that the microspheres have good sustained release action. Effects of the pure LNG microsphere injection and compound LNG microsphere injection on the mouse ovary were compared histologically. The results showed that the compound LNG microsphere injection reduced some of the side effects such as ovary congestion. This points out that the compound dosage form can clinically alleviate the irregular bleeding caused by the administration of LNG alone.

Animals↗
PubMed1991

Determination of hydroxy and peroxy acid derivatives of uroporphyrin in the plasma of patients with congenital erythropoietic porphyria by high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatographic method is described for the determination of hydroxy and peroxy acid derivatives of uroporphyrin in the plasma of patients with congenital erythropoietic porphyria. The porphyrins were extracted from the plasma with 20% trichloroacetic acid-dimethyl sulphoxide (1:1, v/v). The supernatant after centrifugation was chromatographed on a Hypersil-ODS column by gradient elution with 9% (v/v) acetonitrile in 1 M ammonium acetate buffer (pH 5.16) (solvent A) and 10% (v/v) acetonitrile in methanol (solvent B) as the gradient mixture. The method was also suitable for the preparative isolation of the porphyrins.

Chromatography, High Pressure Liquid↗
PubMed1991

High-performance liquid chromatographic assays for protoporphyrinogen oxidase and ferrochelatase in human leucocytes.

Rapid, sensitive and specific high-performance liquid chromatographic assays are described for protoporphyrinogen oxidase and ferrochelatase in human leucocytes. The enzyme reaction products were separated and quantitated by reversed-phase high-performance liquid chromatography with fluorescence detection. The optimal pH for the protoporphyrinogen oxidase assay was 8.6 and the Michaelis constant for protoporphyrinogen IX was 9.78 +/- 0.96 microM (mean +/- S.D.). The mean (+/- S.D.) activity of protoporphyrinogen oxidase in fourteen apparently healthy subjects was 0.146 +/- 0.023 nmol protoporphyrin IX per min per mg protein. In one patient with variegate porphyria, the activity was 0.028 nmol protoporphyrin IX per min per mg protein. The optimal pH for ferrochelatase was 7.4 and with protoporphyrin and Zn2+ as substrates, the Michaelis constants were 1.49 and 8.33 microM, respectively. The mean activity of ferrochelatase in ten control subjects was 0.24 nM Zn-protoporphyrin or 2.05 nM Zn-mesoporphyrin formed per h per mg protein.

Adult↗