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Biomedical subjects

S He

Publications and source records attributed to S He.

At least 181 records · Page 10Linked to original sources
PubMed1998

[Energy metabolism of men in full pressure suit with additional pressure].

The energy metabolism of men in full pressure suit with additional pressure and without additional pressure were measured during rest and exercise. Results show that the rates of energy metabolism of men in full pressure suit with additional 28 kPa pressure and without additional pressure increased as the exercise load increased. The rates of energy metabolism of men in full pressure suit with additional 28kPa pressure had no significant difference during rest and 0.9W exercise, but significantly increased during 8.5 W exercise, as compared with that without additional pressure. It suggested that full pressure suit with 28 kPa did not affect human energy metabolism during rest, but affected during exercise.

Aerospace Medicine↗
PubMed1998

[Effects of hypoxia and qigong on urine malondialdehyde, superoxide dismutase and circulating endothelial cell in humans during simulated weightlessness].

Changes of lipid hyperoxidation and amount of circulating endothelial cells under simulated weightlessness and factors that may influence these changes were observed in 3 groups of subjects (5 in each group) exposed to 17d - 6 degrees head down bed rest (HDBR), HD-BR+ hypoxia and HDBR + qigong respectively. The results showed: (1) simple HDBR promotes antioxidation activity and attenuates hyperoxidation of lipids, and hypoxia and have some influence on the former but not on the latter; (2) circulating endothelial cells decreased significantly after simple HDBR for 7 d but recovered to normal when HDBR continued for 17 d. Hypoxia showed no influence on this effect while Qigong alleviated it significantly. It suggests that (1)both hypoxia and Qigong have some influence on the promotion of antioxidation activity but have no influence on the production of oxygen free radicals. (2) Qigong shows some antagonistic effect against the attenuation of circulating endothelial cells by HDBR.

Bed Rest↗
PubMed1998

[Observation on changes of heart rate and energy metabolic rate and their regression under upper and lower limb exercise].

Energy metabolic rate and heart rate were observed in 8 healthy young men during exercise on a bicycle ergometer. The results showed that there is a linear relationship between heart rate and metabolic rate during both upper and lower exercise, only that the metabolic rate is higher during upper limb exercise than during lower limb exercise under the same work load. It suggests that work efficiency may be influenced by mode of exercise.

Adolescent↗
PubMed1998

[Morphological characteristics of fruits and seeds of Chinese Caesalpinia and its taxonomic significance].

OBJECTIVE: To set up a toxonomic approach to the morphological characteristics of fruits and seeds of Chinese Caesalpinia. METHOD: The ripe fruits collected in the field are dried in the shade, are surveyed and described and the fruit's and seed's morphological characteristics. RESULT: The interspecific differences of morphological characteristics among the fruits and seeds are obvious. The characteristics are stable. A key for their identification is given. CONCLUSION: The above approach can be used as the taxonomic criteria for species differentiation.

Caesalpinia↗
PubMed1998

[Species and distribution of Ainsliaea medicinal plants in Guizhou].

OBJECTIVE: To gain a clear idea of the medicinal plant Ainsliaea in Guizhou Province. METHOD: Collecting data and conducting spot investigation. RESULT: The distribution, growing environment and medicinal parts of 16 species and 1 variety of Ainsliaea have been clarified, and an index for their identification is presented. CONCLUSION: The investigation has been proved ture and useful in further studying the medicinal plant Ainsliaea.

Asteraceae↗
PubMed1998

[Diagnosis and treatment of primary hyperparathyroidism].

OBJECTIVE: To study the diagnosis and treatment of hyperparathyroidism. METHOD: 37 patients with primary hyperparathyroidism (PHPT) were confirmed pathologically. The course of the disease varied, the longest one being 14 years and the shortest one 3 months. RESULT: 35 patients had parathyroid adenoma, 1 hyperplasia of parathyroid, and 1 carcinoma of parathyroid. The main clinical manifestation was symmetrical pain of the supporting bones and joints, hypercalcemia, hypercalcinuria, hypophosphatemia, hyper-alkaline phosphatasemia, and increase of iPTH in peripheral blood. X-ray examination showed osteoporosis and decalcification, accompanied with multiple fracture occasionally, we injected (99m)Tc and MiBi into inferior thyroid artery as a demonstration for the diagnosis of tumor of parathyroid. CONCLUSION: The key procedure of the operation was to search for tumor of parathyroid. We used thymus-thyroid ligament as guide and injected methylene blue into the artery during operation to search thyroid.

Adult↗
PubMed1998

[Rotated-chipping phacoemulsification in front of capsule].

OBJECTIVE: The study was designed to investigate the clinical effects of rotated-chipping phacoemulsification in front of capsule. METHODS: Phacoemulsification using rotated-chipping technique in front of capsule with intraocular lens implantation was performed with medium energy and high vacuum on 50 eyes. RESULTS: Rotated-chipping technique was successfully completed in 46 of 50 eyes (92%), unsuccessful cases were related to shallow anterior chamber and incomplete hydrodissection. CONCLUSION: These results suggest that rotated-chipping phacoemulsification be used for cataracts with various sclerotic nuclei and it is valuable to be applied extensively.

Aged↗
PubMed1998

[Effects of tripterygium wilfordii polyglyco - sidium on intraocular inflammatory reaction after intraocular lens implantation].

OBJECTIVE: The effects of tripterygium wilfordii polyglyco - sidium (TWP) on intraocular inflammatory reaction after extracapsular cataract extraction and intraocular lens (IOL) implantation were studied. METHODS: 120 cases with senile cataract were divided into two groups: (1) Patients received TWP after IOL implantation; (2) patients received prednisone after IOL implantation. The slit - lamp was used to observe inflammatory cells and fibrinous exudate in the aqueous humor and cellular deposits on IOL on the 1st, 3rd, 7th and 14th postoperative days. RESULTS: The study indicated that on the 1st, 3rd, 7th and 14th postoperative days the inflammatory cells and fibrinous exudate in the aqueous humor and cellular deposits on IOL were significantly lower in TWP - treated group than that in steroid - treated group (P < 0.05). CONCLUSIONS: TWP is effective in reducing postoperative anterior ocular inflammation after extracapsular cataract extraction and IOL implantation. The TWP is more effective than the steroid in suppressing postoperative intraocular inflammatory reaction.

Aged↗
PubMed1998

[The experimental research of free calcium of the lens epithelial cells in galactose cataract].

OBJECTIVE: To study the changes of free calcium in the lens epithelial cells (LECs) of galactose cataract. METHODS: Wistar rats, 28 days old, were fed with 50% galactose forage to form cataract models. Then the concentration of free calcium of LECs was measured at the 1st, 3rd, 7th, 10th, 14th, 19th days after the galactose diet was given. RESULT: The concentrations of free calcium in LECs of galactose cataract increased apparently and reached the maximum at the 10th day after galactose diet. The maximum was 4 - 5 times higher than that of the normal group. CONCLUSION: The calcium concentration of LECs in galactose cataract increases but the degrees at different phases are not the same. The maximal concentration is at the phase when the cortex is opacified.

Animals↗
PubMed1998

[Studies in immunological diagnosis of Pneumocystis carinii infection].

AIM: To assess the diagnostic value of Pneumocystis carinii(PC) antibodies and circulating antigens detection in alveolar lavage fluid (ALF) and serum. METHODS: The immunosuppressive rat model was used in this study. The PC antigens in both ALF and sera were detected by double sandwich ELISA, and the specific IgG antibody levels in sera were detected by IFA at different times after immunosuppression treatment. The detection results were compared with the corresponding results of PC finding in lung impression smear. RESULTS: The PC antigens in ALF were positive in all infected rats 6-8 weeks after immunosuppression while in control rats were all negative. By comparison, the PC antigens detected from sera were negative in most infected rats. During immunosuppression treatment with steroid, antibody titers in the infected rats rose slightly in some rats. After steroid was withdrawn, PC antigens in ALF became negative gradually but antibody titers rose progressively with time in all rats. CONCLUSION: Detecting PC antigens in ALF may be useful for diagnosing PC infection but these antigens were difficult to be detected in serum. The rise in serum IgG antibody does not necessarily indicate an existing infection.

Animals↗
PubMed1998

An experimental study of the tumour necrosis factor level in aqueous humor after transscleral fixation of intraocular lens.

PURPOSE: The tumour necrosis factor (TNF) level in aqueous humor after transscleral fixation of intraocular lens (IOL) implantation in rabbits and discuss the effect of TNF on postoperative anterior ocular inflammation. METHODS: Twenty-seven pigmented rabbits were divided into three groups. Group 1: transscleral fixation of posterior chamber (PC) IOL implantation; Group 2: Lens of rabbits was removed without IOL implantation; Group 3: the control group, without surgical intervention. On the 1st, 3rd, 7th and 14th postoperative days, aqueous humor samples were obtained. An modified double antibodies indirect sandwich ELISA was used to detected for the presence of TNF. The data were analyzed by using analysis of variance of SAS software. RESULTS: It was found that TNF level in aqueous humor was increased after transscleral fixation of IOL implantation. TNF level reached its maximum on the 14th postoperative day in the IOL implanted group. TNF level on 1st, 3rd, 7th and 14th days postoperatively was significantly the highest (p < 0.05) in IOL implanted group when compared with the other two groups. CONCLUSIONS: There is something physically related to the IOL itself which induces the secretion of TNF or this simply related to mechanical factors related to the presence of the IOL itself, and the manipulation of the iris during lens implantation stimulates TNF secretion. The increase of TNF level may play critical role in anterior ocular inflammation response after IOL implantation.

Animals↗
PubMed1998

Mechanism of action of anti-C1-inhibitor autoantibodies: prevention of the formation of stable C1s-C1-inh complexes.

BACKGROUND: Acquired C1-inhibitor (C1-inh) deficiency is usually associated with the presence of circulating C1-inh autoantibodies. These autoantibodies have been shown previously to bind to two synthetic peptides corresponding to C1-inh amino acid residues 438-449 (peptide 2) and 448-459 (peptide 3) but not to peptide 1 (residues 428-440). MATERIALS AND METHODS: Affinity-purified C1-inh autoantibodies from two patients with acquired C1-inh deficiency were studied for their effects on the inhibition of C1s activity by C1-inh using SDS-PAGE and hydrolysis of a synthetic ester. RESULTS: Functional studies confirmed that the anti-C1-inh autoantibodies abrogated C1-inh activity, and their maximum effect was produced when the concentrations of C1-inh and autoantibody were approximately equimolar. The autoantibodies prevent the formation of the C1s-C1-inh complex, but they do not dissociate the preformed complex, suggesting that the autoantibodies act prior to the formation of the enzyme-inhibitor complex. In the presence of autoantibodies, C1s cleaves C1-inh, and a stable covalent bond between C1s and C1-inh does not form. Peptides 2 and 3, but not peptide 1 inhibited autoantibody activity, thus C1-inh inhibitory activity for C1s was expressed fully. CONCLUSIONS: Our data indicate that the anti-C1-inh autoantibodies convert C1-inh to a substrate by preventing the formation of the stable covalent protease-serpin complex. The data also suggest a possible therapeutic use for peptides 2 and 3 or their derivatives in the management of patients with type II acquired angioedema (AAE).

Autoantibodies↗
PubMed1998

A role for tryptase in the activation of human mast cells: modulation of histamine release by tryptase and inhibitors of tryptase.

Tryptase, the most abundant protein product of human mast cells is emerging as an important mediator and target for therapeutic intervention in allergic disease. We have investigated the potential of tryptase and inhibitors of tryptase to modulate histamine release from human mast cells. Addition of purified human tryptase in concentrations ranging from 1 to 100 mU/ml stimulated a concentration-dependent release of histamine from cells dispersed from tonsil, although not from skin tissue. The reaction dependent on an intact catalytic site being inhibited by heat inactivation of the enzyme, or by preincubating with the tryptase inhibitors APC366 or leupeptin or the tryptic substrate N-benzoyl-DL-arginine-p-nitroanilide (BAPNA). Tryptase-induced histamine release took approximately 6 min to reach completion, appeared to require exogenous calcium and magnesium, and on the basis of inhibition by antimycin A and 2-deoxy-D-glucose, seemed to be a noncytotoxic process. Pre-incubation of cells with tryptase at concentrations that were suboptimal for histamine release had little effect on their responsiveness to anti-immunoglobulin (Ig) E or to calcium ionophore A23187, but at higher concentrations their subsequent activation was inhibited. APC366 significantly inhibited histamine release induced by anti-IgE or calcium ionophore from both tonsil and skin cells, with up to 90% inhibition being observed at a concentration of 100 microM with skin. IgE-dependent histamine release was inhibited also by leupeptin, benzamidine and BAPNA. Tryptase may act as an amplification signal for mast cell activation, and this could account at least partly for the potent mast cell stabilizing properties of tryptase inhibitors.

Benzoylarginine Nitroanilide↗
PubMed1997

Potent induction of a neutrophil and eosinophil-rich infiltrate in vivo by human mast cell tryptase: selective enhancement of eosinophil recruitment by histamine.

Tryptase is the most abundant protein constituent of the secretory granules of human mast cells, but little is known of the contribution of this serine proteinase in acute allergic reactions. We have purified tryptase from human lung tissue by immunoaffinity procedures, and have investigated its potential to provoke an inflammatory infiltrate in vivo. Within 6 h of injection into the skin of guinea pigs, the accumulation of large numbers of neutrophils and eosinophils was observed, and those eosinophils closest to the injection site were partially degranulated. Similarly, injection of tryptase into the peritoneum of mice, even in quantities as low as 5 ng, stimulated the ingress of neutrophils. The response was dose dependent at 3, 6, and 16 h, with increases in median numbers of up to 400-fold. At the later time points eosinophil numbers were increased by up to 10-fold, and there were elevations also in the numbers of lymphocytes and macrophages. In both models, the actions of tryptase appeared to be dependent on an intact catalytic site. Coinjection of heparin with tryptase had relatively little effect on tryptase-induced responses. On the other hand, although histamine did not itself stimulate cell accumulation, over a range of concentrations it altered the cellular composition of the infiltrate induced by tryptase. Addition of histamine to tryptase provoked selective increases in eosinophil numbers of up to fivefold in the mouse peritoneum. Tryptase may provide an important stimulus for granulocyte recruitment in allergic disease.

Adjuvants, Immunologic↗
PubMed1997

Assignment of sweet almond beta-glucosidase as a family 1 glycosidase and identification of its active site nucleophile.

Sweet almond beta-glucosidase is a well studied glycosidase, having been subjected to numerous kinetic analyses and inhibition studies. However, it is not known to which glycosidase family it belongs, nor is the identity of the active site nucleophile known with certainty. It can be inactivated using the specific, mechanism-based enzyme inactivator 2-deoxy-2-fluoro-beta-D-glucopyranosyl fluoride, which functions by forming a stable 2-deoxy-2-fluoro-alpha-D-glucopyranosyl-enzyme intermediate. The glycosylated peptide present in a peptic digest of this trapped glycosyl-enzyme intermediate was identified by use of neutral loss scans on an electrospray ionization triple quadrupole mass spectrometer. Comparative liquid chromatographic/mass spectrometric analysis of peptic digests of labeled and unlabeled enzyme samples confirmed the unique presence of this peptide of m/z = 1041 in the labeled sample. The sequence of this peptide was determined to be Ile-Thr-Glu-Gln-Gly-Val-Asp-Glu by further tandem mass spectrometric analysis in the daughter ion scan mode in conjunction with Edman degradation of the purified peptide. The identity of the labeled side chain was determined by further tandem mass spectrometric analysis in the daughter ion scan mode of a partially purified sample of the labeled peptide subjected to methyl esterification, the fragmentation pattern being consistent only with the first Glu in the sequence being labeled. The sequence around this residue is identical to that surrounding the catalytic nucleophile in many members of glycosidase Family 1, confirming the assignment of this enzyme to that family. The residue labeled is, however, different from that (Asp) identified previously in the enzyme from bitter almonds by use of conduritol epoxide affinity labels, although apparently close in the primary sequence.

Amino Acid Sequence↗
PubMed1997

Retinal direction selectivity after targeted laser ablation of starburst amacrine cells.

Directionally selective retinal ganglion cells respond strongly when a stimulus moves in their preferred direction, but respond little or not at all when it moves in the opposite direction. This selectivity represents a classic paradigm of computation by neural microcircuits, but its cellular mechanism remains obscure. The directionally selective ganglion cells receive many synapses from a type of amacrine cell termed 'starburst' because of its regularly spaced, evenly radiating dendrites. Starburst amacrine cells have a synaptic asymmetry that has been proposed as the source of the directional response in the ganglion cells. Here we report experiments that make this unlikely, and offer an alternative concept of the function of starburst cells. We labelled starburst cells in living retinas, then killed them by targeted laser ablation while recording from individual directionally selective ganglion cells. Ablating starburst cells revealed no asymmetric contribution to the ganglion cell response. Instead of being direction discriminators, the starburst cells appear to potentiate generically the responses of ganglion cells to moving stimuli. The origin of direction selectivity probably lies with another type of amacrine cell.

Acetylcholine↗