Biomedical subjects
Publications and source records attributed to G Meng.
In this paper, the fresh and dried hearts of Cervus nippon and C. elaphus are identified on character, fluorescence and UV spectra. The alcohol extract of the blood of the deer's hearts has mininum absorption at UV 310 nm.
In this paper, the traditional Chinese Materia Medicas--the foetuses of sika deer, red deer and the one of sheep and OX are compared and identified on characters and dissecting characteristices. The comparion and identification table about charaeters and commodity shape drawings is attached.
In this paper, interaction between CP (Cis-ddp or ciplatin) and DNA (deoxyribonucleicacid) was studied using the fluorescence probe as well as the absorption spectra of DAN.
The regulation of megakaryocytopoiesis and thrombopoiesis appears to be under the control of an array of hematopoietic growth factors. To determine the relationship of endogenous thrombopoietic cytokine levels and circulating platelet (PLT) counts, we measured the levels of thrombo-poietin (TPO), interleukin-11 (IL-11), and interleukin-6 (IL-6) in patients with significant thrombocytopenia secondary to both marrow hypoplasia and increased PLT destruction. Increased endogenous levels of TPO and IL-11, but not IL-6, were detected in bone marrow transplant patients with thrombocytopenia following myeloablative therapy (BMT/MAT) (TPO: 1,455.5 +/- 87.3 pg/mL, [PLT 39,600 +/- 7,800/microL], P < .001, n = 12; IL-11: 227.9 +/- 35 pg/mL, [PLT 32,900 +/- 57,000/microL], P < .05, n = 19; IL-6: 25.8 +/- 8.4 pg/mL, [PLT 32,800 +/- 5,057/microL], P > .05, n = 4] v normal donors [TPO < 150 pg/mL, n = 8; IL-11 < 50 pg/mL, n = 9; IL-6 < 10 pg/mL, n = 5 [PLT 203,000 +/- 7,500/microL]. There was a significant inverse correlation between endogenous levels of TPO and IL-11, but not IL-6, and PLT counts in the MAT/BMT patients (TPO: r = -0.57, P < .0001, n = 188; IL-11: r = -0.329, P < .0001, n = 249; IL-6: r = -0.1147, P > .05, n = 62). In patients with immune thrombocytopenia purpura (ITP), with decreased PLT survival, but intact bone marrow megakaryocytopoiesis, endogenous IL-11 levels were significantly increased (328.0 +/- 92.6 pg/mL, [PLT: 20,900 +/- 3,000/microL], P < .05, n = 25). However, endogenous TPO levels remained undetectable (< 150 pg/mL, [PLT 30,500 +/- 5,500/microL], n = 15). These results suggest that there may be differential mechanisms regulating endogenous TPO, IL-11, and IL-6 levels during acute thrombocytopenia and suggest that the absolute number of circulating PLTs may not always be the sole regulator of endogenous TPO levels. Other mpl-expressing cells of the megakaryocyte lineage may contribute to the regulation of circulating TPO levels as well. Our results also suggest IL-11 levels may in part, be regulated by a negative feedback loop based on circulating PLT counts, but also may, in part, be regulated by a variety of inflammatory agonists. Both TPO and IL-11, therefore, appear to be active thrombopoietic cytokines regulating, in part, megakaryocytopoiesis during states of acute thrombocytopenia.
Thrombopoietin (TPO), the ligand for c-mpl, stimulates proliferation of committed megakaryocytic progenitors and induces maturation of megakaryocytes. To better understand factors regulating TPO levels, we measured blood levels of TPO in patients with impaired platelet production due to aplastic anemia (AA) and with platelet destructive disorders, including idiopathic thrombocytopenic purpura (ITP), posttransfusion purpura (PTP), drug purpura (DP), and X-linked thrombocytopenia (XLTP). The TPO receptor capture enzyme immunoassay (EIA) used had a detection limit of integral of approximately-150 to 200 pg/mL. TPO was undetectable in 88 of 89 normal individuals. Eighteen of 19 patients with AA and a mean platelet count (MPC) of 18,000/microliters (2,000 to 61,000/microliters) had markedly elevated TPO levels (mean, 1,467 pg/mL; range, 597 to 3,834 pg/mL). Eight AA patients who responded to immunosuppressive therapy with their MPC increasing to 140,000/microliters (92,000 to 175,000/microliters) had substantial decreases in TPO (mean, 440 pg/mL; range, 193 to 771 pg/mL). Initial TPO levels did not differ significantly between responders and nonresponders. In contrast, all 21 patients with ITP and an MPC of 16,000/microliters (1,000 to 51,000 /microliters) had undetectable TPO levels, as did 6 patients with acute PTP or DP and 2 patients with XLTP. Megakaryocyte mass, reflected in the rate of platelet production, appears to be the major determinant of TPO levels in thrombocytopenic patients rather than circulating platelet levels per se. Measurement of serum TPO may be useful in differentiating thrombocytopenias due to peripheral destruction from those due to thrombopoietic failure.
Thrombopoietin (TPO) is the natural regulator of platelet production in the bone marrow of mammals. This cytokine also seems to play an important role in the development of the erythroid lineage when recovering from anemic conditions. Here we study the effects of various TPO molecules on the recovery of hematopoietic lineages in a mouse model of pancytopenia. Based on previous animal experimentation and clinical experience with other hematopoietic cytokines, we found that daily dosing with TPO augmented the recovery of both the megakaryocyte and erythroid lineages in a mouse model of pancytopenia. However, further experiments showed that no benefit was gained by using more than a single dose of recombinant murine (rm)TPO(335) given 24 h after the initiation of the myelosuppressive treatment. This response to a single dose of rmTPO(335) is dose-dependent. However, the response was attenuated when a truncated, short half-life TPO molecule (rmTPO[153]) was used. Increasing the half-life of the molecule with 10 kDa polyethylene glycol (PEG) does not improve the response. Only when larger PEG molecules (20 kDa or 40 kDa) are linked to the rmTPO(153) is the response to single doses restored to the level of the full-length molecule. These data suggest that, unlike our experience with other cytokines, the commitment of progenitors to a megakaryocytic cell line is accomplished by a single short exposure to TPO.
Recombinant human (rh) factor VIII is a glycoprotein consisting of multiple polypeptides with relative mobilities (M(r)) ranging from 80,000 to 210,000. It is produced in mammalian cells. Single-dose intravenous pharmacokinetic studies were conducted with rh factor VIII (Kogenate rh Antihemophilic Factor, Miles, Inc.) in male mice (21.0-25.8 g) and rats (252.0-254.2 g). Each species received 400 IU/kg, and blood was collected up to 12 hr (mice) or 32.5 hr (rats) post-dose. Immunoreactive factor VIII concentrations in plasma were quantified by a sensitive and specific ELISA. In both species, the disposition profiles were described by the sum of two exponentials. The pharmacokinetics of rh factor VIII in mouse were as follows: clearance, 27.7 ml/hr/kg; initial volume of distribution, 72 ml/kg; steady-state volume of distribution, 148 ml/kg; and terminal half-life, 4.1 hr. In rat, the mean estimates were as follows: clearance, 16.0 ml/hr/kg; initial volume of distribution, 41 ml/kg; steady-state volume of distribution, 125 ml/kg; and terminal half-life, 5.5 hr. These pharmacokinetic parameters for rh factor VIII in animals and human rh factor VIII pharmacokinetic parameters from the literature were evaluated to determine if the parameters can be represented by the allometric relationship, Y = aWb, where Y is the pharmacokinetic parameter, and W is body weight. The following allometric relations were obtained for rh factor VIII: clearance (ml/hr) = 10.4W0.69, half-life (hr) = 7.5 W0.18, initial volume of distribution (ml) = 43.6 W1.04, and steady-state volume of distribution (ml) = 99.1 W0.84. The allometric exponents for each parameter conformed to theory and were within the range of values commonly observed for xenobiotics and therapeutic proteins. These studies suggest that the pharmacokinetics of rh factor VIII in laboratory animals are predictive of the disposition in humans despite the complex nature of its biological interactions and the chemical diversity of the purified material.
Explore the source record for details and available documents.
Ninety-five percent of cases of severe muscular dystrophy with early childhood onset result from mutations in the dystrophin region of the human X chromosome (DMD, McKusick 310200), whereas 5% are thought to result from mutations in autosomal genes. We examined a total of 415 families with at least one living patient whose clinical features suggested DMD. Based on formal genetics, haplotype analysis, and dystrophin determinations, we estimate that one in eight (11.8%) sporadic male patients carries autosomal rather than X chromosomal mutations.
We present the results of a study of the rate and origin of mutations in Duchenne muscular dystrophy (DMD). Depending on the type of mutation (deletion/duplication or point mutation) present in the patient, there are widely varying ratios of male to female mutation rates. In deletions, the male mutation rate is only 30% of the female one. In non-deletional/non-duplicational mutations (presumably containing a high proportion of point mutations) the male mutation rate is at least 2.2 as high as the female one and probably much higher. Allowing for the presence of autosomal recessive phenocopies we find that k in non-deletional/non-duplicational mutations is 40.3. These findings mean that the vast majority of deletions arise in oogenesis, while most point mutations stem from spermatogenesis. Previous investigations have shown that in other diseases and genes, most notably haemophilia B and A, but also the ZFY and ZFX genes, the male mutation rate for point mutations tends to be higher than the female one. Our results can be seen as a confirmation of this for the special case of DMD. The influence on risk figures is considerable. As an example, the risk of the mother of an isolated case of DMD without an apparent structural anomaly of the gene of being a carrier increases from 67% to at least 76%. Given the estimate of 40.3 for k, allowing for the presence of autosomal recessive phenocopies mentioned above, it increases even further to 98%. However, as confidence intervals are still large, more data are needed to improve the estimates. Germinal mosaicism in this context is discussed.
For the performance of clinical drug trials in the therapy for bronchial hyperresponsiveness, unspecific inhalatory provocation tests are generally employed to judge therapeutic success. In particular, the parameter-specific provocation doses are considered to be the main target values. However, it must be considered that these provocation doses are not equally calculable for every patient in the same way and at any examination time. This leads to the fact that the number of evaluable case studies is often appreciably lower than the number of test participants and that a meaningful therapy group comparison may even not be possible under certain circumstances. An evaluation model is presented here in order to fully exploit the obtained data; in this the percentile changes of the function parameters (estimated by linear regression) at a defined dose of the provocation substance are analyzed. In analogy, a survival time model and, as a supplement, a best case/worst case analysis are performed for further statistical evaluation. With the present procedure, an evaluation with inclusion of all test participants is possible. In contrast to the previously used evaluation procedures, this allows a reliable statistical confirmation of the results of clinical tests in the therapy for bronchial hyperresponsiveness.
The human lysozyme is an enzyme with potential importance in clinical and industrial application. Owing to the limitation of its natural resource, we are making an attempt to produce the enzyme with the aid of recombinant DNA technology. Twenty-four segments with length ranging from 26 to 38 nucleotides were chemically synthesized by solid phase. The oligonucleotides were joined to form DNA duplexes by two different ligation methods. The entire gene covers a start signal ATG and a BamHI restriction site at its 5' end, and two stop signals TAA TGA and a SphI restriction site at its 3' end, besides the structural gene of human lysozyme. The synthetic gene was cloned into vector M13. The positive colonies were confirmed by dot-blot hybridization and analysis by restriction enzymes. The DNA sequence of the cloned enzyme gene was proved to be correct by M13 dideoxynucleotide chain termination method. The study on gene expression is under way.
Thirty-three patients with anaplastic carcinoma of the thyroid were treated during the past 30 years with 27 cases of simple anaplastic carcinoma and the other 6 found also with some differentiated carcinoma component. survival rate of 3.5 and 10 years were 35.5%, 36.7% and 29.6%, respectively. The survival rate of patients younger than 45 years were higher than older, and of those with tumor size less than 4cm in diameter were better than that with larger size. Patients received radical surgery plus adjuvant therapy had better survival rate, and patients with differentiated carcinoma component had better survival rate. This study suggested that surgical treatment plus adjuvant therapy is the treatment of choice in anaplastic carcinoma of the thyroid, and the extent of the operation must be dependent on the size of primary tumor.
The rapid progress of research on the structure of the dystrophin gene has enormously increased our understanding of the molecular basis of Duchenne (DMD) and Becker (BMD) muscular dystrophy. Apart from "classical" clinical presentations, asymptomatic or only mildly affected individuals with deletions in the dystrophin gene have now been reported. We describe two families which were initially classified as metabolic myopathies, until the diagnosis of atypical BMD was established after dystrophin analysis at the protein and DNA level. A modern diagnostic approach to myopathies should, therefore, not only include morphological and biochemical investigations, but also be extended to the analysis of the dystrophin gene.
We present the results of an international collaborative study aimed at estimating the ratio of male to female mutation rates in Duchenne muscular dystrophy based on the method of C. Müller and T. Grimm. With a sample size of 295, this ratio is found to be very close to 1, thus giving evidence for equal mutation rates in males and females in Duchenne muscular dystrophy.
The relationships between the results of Beijing International Marathon Races and the corresponding weather conditions are analysed quantitatively. There are obvious interrelationships between the marathon results and weather factors such as air temperature, wet bulb temperature and human biometeorological indices. For example, the correlation coefficient between the average times of the top ten finishers and temperature is r = 0.8910. The meteorological conditions are classified into three categories, suitable, moderate and unsuitable for running a marathon race, and the optimum meteorological index is given. Also the concept of a meteorological result, i.e. the part of the actual performances fluctuating with the changes in weather conditions, is presented. This plays an important role in some kinds of sports such as marathon racing. Finally, the results of physiological tests are given, which illustrate the physiological reactions of long- and middle-distance runners to the surrounding temperature.
The dystrophin gene has been mapped to a pair of microchromosomes in Gallus domesticus. In situ hybridization using a pool of biotinylated human cDNA probes allowed detection of this huge single-copy sequence without having to employ isotopic labeling. The autosomal nature of the DMD gene in chicken is supported by molecular data from quantitative Southern blot analysis and is in sharp contrast to that in all eutherian mammals studied, where it is a characteristically X-linked locus. With previous data taken into consideration, these results should prove significant in understanding the evolution of sex chromosomes during speciation as well as highlighting the importance of avian microchromosomes.
The time, volume and method in preparing decoction of Epimedium grandiflorum have been studied by orthogonal design through the determination of icariin. The factors which influence decoction-making conditions are in the order of: volume greater than time greater than method.