Biomedical subjects
Publications and source records attributed to L Wan.
We describe a PC-based active-capture system for recording digital images from a scanning electron microscope. The system is based on a National Instruments data-acquisition board and a Pentium computer, controlled by software that we have written in Visual Basic.
A new contraceptive (LNG rod implants, Jadelle, Leiras Oy's registered trademark for rod implants) was prospectively evaluated in randomized 5 year comparison with Norplant (Population Council's registered trademark for contraceptive implants releasing levonorgestrel) capsule implants. The study involved 1198 women at seven centres. No pregnancies occurred in the first 4 years. At 5 years, the cumulative pregnancy rate was 1 per 100 users or less for each regimen. Annual discontinuation rates averaged 11-12 per 100 users (P > 0.05), corresponding to 5 year continuation rates of 55.1 for rods and 53.0 per 100 for capsules. Mean annual discontinuation rates for menstrual disturbances were 3.5 and 4.2 per 100 for rod and capsule implants respectively (P > 0.05), and mean annual removal rates for medical problems were 3.5 and 3.0 per 100 (P > 0.05) respectively. Apart from menstrual problems, headache, weight gain and acne were the principal medical reasons for removal. In proportional hazard analyses, family formation variables, age, parity and desire/non desire for another child, recorded at admission, significantly affected discontinuation rates for major decrement categories and for all reasons combined. Mean rod removal time was half that of Norplant (P < 0.01); complications of rod removal were at a lower rate. With these contraceptives indistinguishable in performance except for ease and speed of removal, LNG rod implants appear to be preferable to Norplant for use through 5 years by virtue of relative ease of removal.
Human transportin1 (hTRN1) is the nuclear import receptor for a group of pre-mRNA/mRNA-binding proteins (heterogeneous nuclear ribonucleoproteins [hnRNP]) represented by hnRNP A1, which shuttle continuously between the nucleus and the cytoplasm. hTRN1 interacts with the M9 region of hnRNP A1, a 38-amino-acid domain rich in Gly, Ser, and Asn, and mediates the nuclear import of M9-bearing proteins in vitro. Saccharomyces cerevisiae transportin (yTRN; also known as YBR017c or Kap104p) has been identified and cloned. To understanding the nuclear import mediated by yTRN, we searched with a yeast two-hybrid system for proteins that interact with it. In an exhaustive screen of the S. cerevisiae genome, the most frequently selected open reading frame was the nuclear mRNA-binding protein, Nab2p. We delineated a ca.-50-amino-acid region in Nab2p, termed NAB35, which specifically binds yTRN and is similar to the M9 motif. NAB35 also interacts with hTRN1 and functions as a nuclear localization signal in mammalian cells. Interestingly, yTRN can also mediate the import of NAB35-bearing proteins into mammalian nuclei in vitro. We also report on additional substrates for TRN as well as sequences of Drosophila melanogaster, Xenopus laevis, and Schizosaccharomyces pombe TRNs. Together, these findings demonstrate that both the M9 signal and the nuclear import machinery utilized by the transportin pathway are conserved in evolution.
OBJECTIVE: The aim of the work was to improve the operative result of eye socket reconstruction after enucleation. METHODS: The hydroxyapa tite implant of eyeball shape was buried in the scleral shell, which was stitched to the extraocular muscles at the points of muscle attachment so as to create a rotatable eye seat connector. RESULTS: One hundred and two patients have received eye socket reconstruction of this method with improved results. The prosthetic eyes move freely. Follow-up for 6 to 38 months reveals that the results are stable and satisfactory. CONCLUSION: The indigenous hydroxyapa tite implant is a good biomaterial for socket reconstruction.
Exercise ECG indicates information about the heart load status in the exercise test. It is very significant to represent the characteristics of the exercise ECG for evaluating the exercise load test. This article introduces the principle of Winger-Ville Distribution time-frequency analysis and its implementation. By applying this method to analyse exercise ECG, some results were acquired. It is a promising method to do research of the exercise ECG in the time-frequency plane.
Naftopidil(Naf), a novel antihypertensive drug, was determined by HPLC-UV method. The plasma concentration and pharmacokinetics of naftopidil have been investigated in rats after single oral doses of 10, 20 and 30 mg.kg-1. The drug was found to conform to a two-compartment model. Tp was in the range of 0.42 h to 0.90 h. T1/2 beta was 7.08 h after the 10 mg.kg-1 dose, 4.78 h after the 20 mg.kg-1 dose and 5.83 h after the 30 mg.kg-1 dose. The Cmax, AUC and CL/F appeared to be dose dependent at the doses not higher than 20 mg.kg-1. Naf was found in many tissues after a single oral dose of 20 mg.kg-1. The top level tissues were intestine, liver and lung at 15 minutes after administration, while the utero-ovarian tissue was the highest at 6 h. Naf can be extensively metabolized since the total excretion of the parent compound in urine and faeces was less than 1% of the dose. From 82% to 97% of Naf in plasma was shown to be bound to protein.
Carnitine deficiency presents as a major problem in fatty acid oxidation. The use of a plasma carnitine assay can rapidly help to describe this deficiency. The method we describe here requires two simple steps of sample preparation, followed by automated analysis with the Beckman Synchron CX4 random-access chemistry analyzer. The goal of this method development was to reduce the cost of analysis and to allow a greater number of laboratories to perform this assay on demand within 1 h for both free and total carnitine. The method has a linearity of 0-150 micromol/L and a detection limit of 5 micromol/L. The inter- and intraday CVs are <20%. The method agreed closely with both the widely used RIA and spectrophotometric methods.
Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is an abundant nuclear protein that plays an important role in pre-mRNA processing and mRNA export from the nucleus. A1 shuttles rapidly between the nucleus and the cytoplasm, and a 38-amino acid domain, M9, serves as the bidirectional transport signal of A1. Recently, a 90-kD protein, transportin, was identified as the mediator of A1 nuclear import. In this study, we show that transportin mediates the nuclear import of additional hnRNP proteins, including hnRNP F. We have also isolated and sequenced a novel transportin homolog, transportin2, which may differ from transportin1 in its substrate specificity. Immunostaining shows that transportin1 is localized both in the cytoplasm and the nucleoplasm, and nuclear rim staining is also observed. The nuclear localization of A1 is dependent on ongoing RNA polymerase II transcription. Interestingly, a pyruvate kinase-M9 fusion, which normally localizes in the nucleus, also accumulates in the cytoplasm when RNA polymerase II is inhibited. Thus, M9 itself is a specific sensor for transcription-dependent nuclear transport. Transportin1-A1 complexes can be isolated from the cytoplasm and the nucleoplasm, but transportin1 is not detectable in hnRNP complexes. RanGTP causes dissociation of A1-transportin1 complexes in vitro. Thus, it is likely that after nuclear import, A1 dissociates from transportin1 by RanGTP and becomes incorporated into hnRNP complexes, where A1 functions in pre-mRNA processing.
In a randomized three-year clinical trial at seven clinics, the performance of levonorgestrel rod (LNG ROD) implants used by 600 women was compared with that of soft tubing NORPLANT implants used by 598 women. No pregnancies occurred in either group of women and, accordingly, body weight did not affect the efficacy of either type of implant. There were neither statistically significant nor important differences in termination rates for any reason over the three years. Complaint and illness rates during use of either of the two implant types were statistically indistinguishable and were attributable to the same set of conditions. Seventy-one per 100 of the women using each implant regimen continued to the three-year point, for an average annual continuation rate of 89 per 100. Removals of LNG ROD implants were accomplished in about half the time required for removal of Norplant capsule implants (p < 0.001).
In a three-year randomized trial that included 398 women, blood samples were collected for the purpose of assaying levonorgestrel concentrations in women using a new two-rod contraceptive implant system or an earlier implant formulation, Norplant-2 implants. Sample collection was at 1, 3, 6, 9, and 12 months after placement and semiannually thereafter through three years. Resulting assays and analyses showed that levonorgestrel concentrations of each implant formulation decreased significantly with time after placement, with increasing body weight, and with ponderal index. In the third year, several measures indicated that concentrations of the contraceptive drug were higher in women using the LNG ROD implants than in users of the original formulation. No pregnancies occurred among women in either group in the three years. This study provides evidence that the minimum levonorgestrel concentration needed to protect against pregnancy is below 200 pg/ml, and possibly is below 175 pg/ml.
A high incidence of irregular uterine bleeding is the primary patient complaint limiting the utility of long term, progestin-only contraceptive agents such as Norplant. The onset of hemorrhage requires both inadequate hemostasis and impaired vascular integrity. Thus, we first tested whether Norplant-associated endometrial bleeding was accompanied by altered expression of perivascular stromal cell tissue factor (TF), the primary initiator of hemostasis. Norplant effects on TF messenger ribonucleic acid (mRNA) and protein expression by endometrial stromal cells were assessed by in situ hybridization and immunohistochemical examination of endometrial biopsies obtained from normally cycling control women (n = 14) and from patients experiencing Norplant-induced abnormal uterine bleeding (n = 24). TF mRNA and protein expression was increased 150% in secretory vs. proliferative phase endometrial specimens. By contrast, endometrial TF mRNA and protein levels were reduced during 1-6 months of Norplant treatment by about 2-fold (P < 0.05 for protein) compared to the values for control secretory phase specimens. These changes were consistent with observations that patients on Norplant begin to bleed during this interval. Further reductions of TF mRNA and protein levels to 2- and 3-fold of those in secretory phase control specimens were observed in endometria obtained after 6-12 months of Norplant therapy (P < 0.05 and P < 0.01, respectively). A modest rebound in TF mRNA and protein expression was observed after 12 months of Norplant therapy, which occurred commensurate with reduced patient complaints of abnormal uterine bleeding. Pathologically enlarged venous sinusoids were ubiquitous in endometrial specimens obtained after Norplant therapy. The combination of fragile blood vessels and reduced TF expression may account for bleeding in patients receiving Norplant therapy.
OBJECTIVE: To evaluate the implementation of mid-term National Tuberculosis Control Programme (NTP). METHOD: The construction of tuberculosis control organizations, implementation of tuberculosis control work, etc, were investigated retrospectively. RESULTS: Almost all the tuberculosis control indices had reached the mid-term NTP target except the case-finding index. CONCLUSIONS: Much more efforts are required to reach the NTP target of year 2000 that the prevalence of smear positive pulmonary tuberculosis decrease to 70 per 100,000 populations.
This paper deals with the ethnopharmacology of P. emblica, a traditional herbal medicine used by many peoples in the world. The paper introduces the biological characters, geographical distribution-patterns, chemical constitution and pharmacology of the plant. By cross-cultural comparative study, this paper indicates that there are 17 countries and nations of the world using various parts of P. emblica in their medical treatment. The medicinal plant is good for anti-hepatitis, anti-cancer, anti-tumor and regulation of stomachal function. The plant is also regarded as a traditional immunomodulator and a natural adaptogen. The result of the study reveals that P. emblica is an important traditional medicine with broad prospects.
AIM: To evaluate biological effects in vitro of transforming growth factor-beta (TGF-beta) and/or insulin on proliferation of the human periodontal ligament (PDL) cells. METHODS: Cell cultures and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] colorimetric assay. RESULT: TGF-beta at concentrations of 0.1 to 10 micrograms/L and insulin at 10 to 1,000 U/L had significant proliferative effects on human PDL cells (P < 0.01). From the 3rd day, the significant proliferation of PDL cells by TGF-beta or insulin were observed (P < 0.01) and lasted to the 5th day. The effect of combination of TGF-beta with insulin was the most significant one (P < 0.01). CONCLUSION: TGF-beta and/or insulin may be valuable in promoting the regeneration of periodontal connective tissue.
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OBJECTIVE: To study pre-hospital sudden death so as to reduce the death rate. METHOD: 814 pre-hospital deaths were randomly selected from January 1990 to May 1994 for a retrospective study. RESULTS: 616 deaths (75.7%) showed a history of cardiac disease and hypertension. The age for high sudden death rate ranged from 50 to 69 years (53.9%). Most of the cases (87.8%) were found in their homes. 21 cases (2.58%) successfully recovered. CONCLUSIONS: The key points to improve the success rate of pre-hospital sudden death are: completing Beijing Emergency Medical Center's emergency care network so as to decrease the emergency care radium and shorten the emergency care time; disseminating emergency care knowledge on CPR and CPR technique.
Immunofluorescence staining method and fluorescence spectrophotometry were used to study the synthesis of extracellular matrix proteins in periodontal ligament cells (PDL cells) when exogenous fibronectin (FN) existed. The results showed that the right amount of exogenous FN (0.044 mumol/l) could increase the amount of type I collagen and type III collagen in PDL cells (P < 0.01), inhibit the synthesis of FN itself (P < 0.01). It suggested that exogenous FN can effect the synthesis of extracellular matrix proteins so as to promote a new connective tissue attachment formation.
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