Biomedical subjects
Publications and source records attributed to G Li.
The content of arsenic in sulfur before and after processing was determined. The result shows that the content in raw materials is 8-15 times higher than that of the processed product, which implies that the toxicity of sulfur is obviously reduced by processing.
Australiside A(1), a new diterpenoid glucoside, was isolated together with thymidine(2), caffeic acid(3), p-coumaric acid(4) and caffeic-beta-D-glucoside(5) from Cuscuta australis. Based on spectral analysis and physico-chemical properties the structures of the above-cited five compounds were identified. The structure of compound 1 was deduced as 4-oic acid-7-oxo-kaurene-6 alpha-O-beta-D-glucoside. Compounds 2, 3, 4 and 5 were obtained from Cuscuta for the first time.
Seven alkaloids were isolated from the seed of Sophora alopecuroides and identified to be oxymatrin, oxysophocarpine, cytisine, matrine, sophocarpine, sophoridine and nicotine respectively by comparing chromactographic and spectral characteristics with authentic known compounds. Nicotine was isolated from Sophora for the first time. The activity of extracts and alkaloids against cancer, virus, dermatophytes and bacteria was carried out in vitro.
OBJECTIVES: To observe the effects of reflux esophagitis(RE) on the lung function and airway reactivity, and study the mechanism of airway hyperresponsiveness(AHR) in patients with RE. METHODS: Lung function measurements and airway provocation tests were performed in 31 RE patients and 35 control subjects. TXB2 and PGF1a were determined in 20 cases of each group. RESULTS: In RE patients the lung function was lower and the rate of AHR was higher than control subjects (P < 0.05). Among RE patients 25% had higher airway sensitivity (Dmin < 3 u). The TXB2 of RE patients with AHR was higher than those without AHR. Dmin correlated significantly with TXB2 (r = -0.653, P < 0.05). CONCLUSIONS: RE could damage the lung function. The rate of AHR was 61%, the high airway sensitivity was probably potential asthma, and TXB2 may play a role in the pathogenesis of AHR.
Palea steindachneri is a precious animal and its carapacial bones and plastral bones are expensive Chinese medicinal materials. This paper introduces the biologic characteristics and cultured methods of Palea steindachneri. It provides a valuable information for the culture of Palea steindachneri.
For exploring cellular immunity disturbances in children with acute lower respiratory infection (ALRI) caused by respiratory syncytial virus (RSV) the level of interleukin-2 (IL-2) soluble interleukin-2 receptor (sIL- 2R), the expression rate of interleukin-2 receptor (IL-2R) on T cells and percentage of T lymphocyte subsets were determined in peripheral blood of 25 acute cases. The results showed that compared acute stage of RSV associated ALRI with recovery stage and control group, the level of peripheral blood IL-2 and expression rates of IL-2R decreased but the level of sIL-2R increased. The level of IL-2 had positive correlation with IL-2R and percentage of CD4+ cells, but had negative correlation with sIL-2R and percentage of CD8+ cells. The plasma sIL-2R level had negative correlation with expression rate of IL-2R, but had a positive correlation with clinical severity. These results suggested that human body had a functional disturbance in cellular immunity when infected with RSV.
The partial envelope (E) protein gene of Dengue virus type 4 (DV4), derived from the serum of a patient with dengue fever in an epidemic during October 1993 in Guangdong Province of China, was cloned and sequenced. DV RNA was converted to cDNA by reverse transcription with random primers before the polymerase chain reaction using DV4 specific primers was performed. The amplified product of 421bp was subsequently filled in 3' recessed ends, isolated, purified and inserted into pUC18 and pUC19 plasmid vector. Their sequences were determined by dideoxy nucleotide chain termination method. A comparison between DV4 Chinese strain and several other previously reported strains shows the homology to be 93.72% for the same dengue serotype, 61.26-64.40% for the other dengue serotypes, only 40.31% for Japanese encephalitis virus, which belongs to the member of flavivirus family. A conserved sequence with 12 amino acids observed from deduced protein sequence probably represents an essential functional element among flavivirus family.
OBJECTIVE: To explore the clinical implication of soluble interleukin-6 receptor(sIL-6R) in patients with malignant hematological diseases. METHODS: Serum levels of sIL-6R in 26 multiple myeloma (MM), 34 acute leukemia (AL) and 17 non-Hodgkin's lymphoma (NHL) patients before and after chemotherapy and 20 normal controls were measured by immunoenzymetic assay. RESULTS: Serum levels of sIL-6R in MM and B-ALL patients at diagnosis were significantly higher than that in normal controls (P < 0.001, and P < 0.01, respectively), while the levels in ANLL, T-ALL and NHL patients were normal. Serum beta2 microglobulin and creatinine levels in MM patients with elevated serum sIL-6R were higher than that in patients with normal sIL-6R levels(P < 0.001, and P < 0.05, respectively). Serum sIL-6R levels did not relate to clinical stages. Serum lactic-dehydrogenase (LDH) levels in B-ALL patients with elevated sIL-6R were higher than that in patients with normal sIL-6R levels (P < 0.05). Serial measurement of serum sIL-6R in MM patients showed a good correlation with serum M-protein and plasma cell percentage in bone marrow. CONCLUSION: Serum sIL-6R levels were significantly increased in MM and B-ALL patients, and it is a predictive factor for responsiveness to chemotherapy and an indicator of disease activity.
A modified method for the analysis of vitamin K1 in Cephalanoplos segetum (Bunge) Kitam, an edible wild herb, is proposed in this paper. The ground herb sample was extracted with CHCl3, followed by evaporation to dryness with nitrogen. The residue was dissolved with methanol, filtered through 0.5microm micropore membrane and then determined on a Novapak C18, 150mm x 3.9mm i.d., column with methanol/isopropanol (70:30) as mobile phase and UV-248nm as detector. Recovery was more than 95% with CV 1.23%. The method is simple and accurate without saponification, extraction and evaporation procedures as those used previously.
A new type of SnO2/SnCl2 semiconductor as detector in gas chromatography has been developed. The sensing crystalloid with SnO2 as main block has an outstanding sensitivity to the reducing gases in a certain oxidative circumstance. The reducing gases can be reversibly adsorbed on the surface of crystal and make the resistance of the sensing element changed. Therefore, this type of sensing element may be used as detector in GC. We studied and prepared such sensing element with SnCl2 as catalyst to improve the sensitivity. An optimum procedurefor preparation has been received. We also discussed the possibilily as the gas-sensing element to replace the flame ionization detector in GC. The results showed that at the condition of 300 degrees C, the sensitivity, stability, detectability and linear range were satisfactory. This new type of detector can meet the needs of practical sample analysis.
In this paper, separation of water soluble vitamins C (VC), B1 (VB1) and B6 (VB6) has been studied preliminarily by capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) with a home-made amperometric electrochemical detector at the working electrode [carbon fiber (5 microm o.d.)] potential of 510-540 mV (vs. SCE). It has been shown that each of the three vitamins has more than one peak in NH3-NH4Cl (pH 9.0) which were mainly caused by the decomposition products in weak base medium and by heat except those from impurities. The electrochemical detector has better performance for the three vitamins from CZE and MECC. They can be separated either by CZE or by MECC. The separation by CZE is better than that by MECC with sodium dodecyl sulfate (SDS). SDS and buffer acidity can influence the retention time, peak sequence and height. The separation efficiency of CZE in 0.01 mol/L NH3-NH4Cl was 468 800 theoretical plates for VC.
At the presence of Tween-80 in acid medium, Fe(III) Co(III) and SCN- are changed into coloured complexations and quantitatively absorbed on the resin. The apparent molar absorptivities of resin phase are epsilon Fe = 2.4 x 10(5)L x mol(-1) x cm(-1) at 490nm and epsilon Co = 2.1 x 10(5)L x mol(-1) x cm(-1) at 630nm by spectrophotometry. Beer's law is obeyed by Fe(III) and Co (III) in the range of 0-8microg/25mL and 0-15microg/25mL. method has been applied to natural water. Relative standard deviations are 1.7% and 5.5%, respectively.
BACKGROUND: A deployed U.S. Navy aircraft carrier is a hazardous environment where work and recreation intermingle. Injuries causing time lost from assigned duties may impact aviation safety and operational readiness. This descriptive study examines injuries sustained on the flight deck, in the hangar bay, or in the gym of a deployed aircraft carrier, focusing on those injuries resulting in lost duty days. METHODS: Injuries recorded by the ship's medical department were analyzed, relating lost duty injuries to the following parameters: division, rank, time of day, location of injury event, whether injury was job-related or recreational, type of recreational activity, and mechanism, type, and anatomic site of injury. RESULTS: During a 6-mo deployment, 335 injuries occurred in the shipboard locations studied. More than one-third (36%) of these injuries resulted in lost duty time, accounting for 768 man-days of lost duty during the deployment. Recreational injuries represented 19% of all injuries, but 25% of all lost duty injuries, a statistically significant contribution to lost duty time when compared to job-related injuries (p = 0.04). The sports of basketball, volleyball, and football were more likely than other recreational activities to cause injuries resulting in lost duty time (p = 0.01). Musculoskeletal injuries, particularly injuries involving the lower extremity, neck, and back, were also associated with increased risk of lost duty time (p < 0.001). CONCLUSIONS: Although recreational injuries are less frequent than job-related injuries in the study population, they contribute disproportionately to lost duty time. Injury prevention in similar environments should address recreational as well as work-related activities.
The role of the tumor suppressor p53 in repair of ultraviolet light (UV)-induced DNA damage was evaluated using a host-cell reactivation (HCR) assay. HCR determines a cell's ability to repair UV-damaged DNA through reactivation of a transfected CAT reported plasmid. Most UV damage is removed through nucleotide excision repair (NER). Primary murine keratinocytes isolated from p53-deficient and wild-type p53 mice were used in the HCR assay. The NER was reduced in p53-/- keratinocytes as compared with p53+/+ keratinocytes. The reduced DNA repair in p53-/- mice was confirmed with a radioimmunoassay comparing cyclobutane dimers (CPDs) and (6-4) photoproducts in p53+/+ and p53-/- keratinocytes after the cells were exposed to UV irradiation. Our results demonstrate that wildtype p53 plays a significant role in regulating NER. Furthermore, as there is evidence that p53 protein levels decrease after keratinocytes become differentiated, we sought to determine whether p53 plays a role in NER in differentiated keratinocytes. Differentiation of the keratinocytes by increasing the Ca2+ concentration in the culture media resulted in a marked reduction in NER equally in both p53+/+ and p53-/- groups. This finding suggests that reduced DNA repair after differentiation is p53 independent. A similar reduction in HCR was confirmed in differentiated human keratinocytes. These data, taken together, indicate that p53 or p53-regulated proteins enhance NER in basal undifferentiated keratinocytes but not in differentiated cells. As nonmelanoma skin cancers originate from the basal keratinocytes, our findings suggest that loss of p53 may contribute to the pathogenesis of this common skin cancer.
A 62-year-old man with advanced gastric cancer was admitted with a swelling of the left scrotum. He had undergone subtotal and total gastrectomies 10 and 5 years earlier, respectively. A hard mass was palpated along the left spermatic cord associated with hydrocele testis. A left high orhiectomy was performed. Multiple small nodules were noted on the surface of the tunica vaginalis. Also, a tumor in the spermatic cord was present at the level of the internal inguinal ring, protruding into the peritoneal cavity and adherent to the colon. Peritonitis carcinomatosa was recognized. Histopathological diagnosis was tubular adenocarcinoma showing extensive vascular invasion, consistent with a metastasis from gastric cancer.
Neoadjuvant endocrine treatment before radical prostatectomy is designed to reduce the positive margin rate and therefore the risk of recurrence. It usually consists of complete androgen blockade for 3 months, but no consensus has been reached concerning the type of blockade and the optimal duration. The main histological changes consist of glandular atrophy with pycnosis and vacuolization of tumour cells. These changes could reflect increased apoptosis. The residual tumour is usually small. PIN become rare, raising the problem of possible chemoprevention. The overall result is a markedly increased frequency of intracapsular tumours and a reduction of at least 50% of positive margins. However, some authors consider that this is simply due to a more detailed histological examination. The frequency of seminal vesicle and lymph node involvement does not appear to be modified. Endocrine therapy could act on the apoptosis-proliferation balance and also decrease the number of circulating cells. However, the intermediate results of randomized studies are contradictory. As improvement in overall survival remains the main objective, only a longer follow-up will be able to clearly determine the value or uselessness of neoadjuvant endocrine treatment before radical prostatectomy.
OBJECTIVE: To investigate the clinical manifestations and factors relating to prognosis in biliary atresia (BA). METHODS: Twenty-four cases were reviewed on clinical manifestations and bile flow after operation. All patients underwent hepatic portoenterostomy. RESULTS: Twenty-three cases (95%) got bile flow postoperatively. Sixteen (69%) of 23 patients had 27 episodes of cholangitis. There were significant differences (P < 0.05) in the amount and bilirubin concentration of bile flow before and after cholangitis. Cholangitis also affected the life quality of BA patients. CONCLUSION: We consider that early finding and prevention of cholangitis can improve the prognosis of BA patients.
OBJECTIVE: To determine whether circulating tumor cells are present in patients with localized or disseminated neuroblastoma (NB). METHODS: Sixteen pediatric malignant tumor cell lines, including 10 NB, 4 primitive neuroectodermal tumor (PENT), 2 Wilms' tumor and 39 samples (tumor tissue, bone marrow and peripheral blood) from 8 patients with NB, were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) using two markers: neuroendocrine protein gene products 9.5 (PGP 9.5) and tyrosine hydroxylase (TH). RESULTS: Analysis of RT-PCR products by agarose electrophoresis demonstrated that in culture cell lines the specificity for NB was highest in TH (9/10 with NB, 3/4 with PNET, 0/2 with Wilms' tumor) and the sensitivity was highest in PGP 9.5 10(-7). PGP 9.5 and TH mRNA were undetectable in the peripheral blood mononuclear cells (PBMNC) from normal children. Expression of these markers in 8 patients with NB at diagnosis and during treatment was found positive in 5 out of 8, all had been proved paralleling with their disease status. Two of the 5 became negative after further treatment. CONCLUSIONS: These systems allow the detection of circulating NB cells with higher sensitivity and specificity. When RT-PCR is clinically used for the detection of NB cells in blood, that both PGP 9.5 and TH should be selected is recommended. The assessment of bone marrow alone might not be used as a single index of tumor dissemination.