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Biomedical subjects

B Sun

Publications and source records attributed to B Sun.

At least 289 records · Page 16Linked to original sources
PubMed1991

[An experimental research on the acute lung injury induced by endotoxin].

Using a goat endotoxin model with chronic lung lymph fistula, we continuously measured lung lymph flow (QL), lymph to plasma protein ratio (L/P), pulmonary arterial pressure (Ppa) and the level of thromboxane B2 in plasma and lymph. We also observed the changes of ultrastructure in leukocyte and pulmonary parenchyma. It showed that the alteration can be divided into two intervals: phase I is characterized by the abrupt onset of pulmonary hypertension and in phase II, the capillary permeability increased predominantly. It was suggested that this model is a good research tool for studying adult respiratory distress syndrome (ARDS).

Animals↗
PubMed1991

Application of a new ventilator-multi-plethysmograph system for testing efficacy of surfactant replacement in newborn rabbits.

We applied a new ventilator-multi-plethysmograph system to evaluate the effect of surfactant replacement in newborn rabbits under well controlled, nearly physiological conditions characterized by normal ECG and adequate PCO2 in right ventricular heart blood obtained at the end of the experiment. Up to 10 animals were ventilated in parallel with a pressure-constant common respirator system. Using a working pressure of 4.9 kPa (50 cmH2O), we could adjust the pressure delivered to each animal within the range of 0.49-4.4 kPa (5-45 cmH2O), by changing the length of an open high-resistance tube constituting the outflow limb of the connection between the common ventilator tube and the tracheal cannula. Immature newborn animals obtained after 27.5 days gestation and ventilated for 30 min with a tidal volume of 8-10 ml.kg-1 had a mean +/- SD lung-thorax compliance of 4.2 +/- 1.1 ml.kPa-1.kg-1 (0.41 +/- 0.11 ml.cmH2O-1.kg-1) and PCO2 of 8.5 +/- 1.9 kPa. In littermates treated at birth with a large dose of natural surfactant (Curosurf, 200 mg.kg-1, compliance increased to 6.0 +/- 1.0 ml.kPa-1.kg-1 (0.68 +/- 0.10 ml.cmH2O-1.kg-1) (p less than 0.01) and PCO2 decreased to 6.9 +/- 1.2 kPa (p less than 0.01). Near-term animals, obtained at 30 days gestation and ventilated under similar conditions had a compliance of 7.2 +/- 0.9 ml.kPa-1.kg-1 (0.71 +/- 0.09 ml.cmH2O-1.kg-1) and PCO2 of 6.4 (1.2) kPa. Administration of surfactant (same dose as above) to these mature animals at birth had no adverse effects.

Animals↗
PubMed1991

[Ultrasonically nebulized hypertonic saline as a provocation agent in asthmatics].

We investigated nonspecific reactivity to inhaled aerosol of hypertonic saline. Hyperosmotic challenge carried out with NaCl solution of 0.9-fold increasing concentration from 2.7 to 7.2%. Each aerosol inhalation at different concentration was carried out for 5 min. An ultrasonic nebulizer was used to generate aerosol of NaCl solution that was delivered by tubing to a two-way valve. FEV1 was measured 1.0, 1.3 and 2 min after each concentration and did further at 5 min intervals until the value reached a plateau or began to rise. The challenge was terminated when the percentage fall in FEV1 was greater than 20%. The response to HS was expressed as PC20. In the 26 subjects with stable asthma 23 were responsive to HS. The PC20-HS was from 1.65 to 6.06%. The peak bronchoconstrictor effect of HS inhalation occurred 3 min after inhalation and its mean duration was 45 min. We also compared bronchial response to HS with that to methacholine (MCH). There was a significant correlation between PC20-HS and PC20-MCH (r = 0.538, P less than 0.01). The method used for HS challenge is simple, rapid, inexpensive and provide a new means for determination of bronchial hyperreactivity.

Adolescent↗
PubMed1991

[Airway challenge test with propranolol].

We investigated airway response to propranolol in 48 asthmatics, 17 subjects with chronic bronchitis and 19 normal subjects. The positive rate for propranolol challenge was 93.8% in asthma group, 5.9% in chronic bronchitis group while none in normal group had positive response. The challenge was highly reproducible, and it had few side-effects. This indicated that the challenge was specific and sensitive in diagnosis of asthma, it was a safe, reliable method of measuring non-specific airway responsiveness. Furthermore we also demonstrated that PC20 for propranolol did not relate to PC20 for methacholine, and that the calibre of airway did not significantly influence the airway response to propranolol.

Adolescent↗
PubMed1990

Blood supply of the flexor digital tendon in the hand and its clinical significance.

An anatomical study on the blood sources and vascularity of the flexor digital tendon was conducted in the upper extremities of fresh cadavers by means of arterial injection and meticulous dissection of the transparent tendon under the microscope. According to whether or not synovial membrane surrounded the tendon, the flexor digital tendon can be divided into 2 regions: non-synovial and synovial. The major intrinsic blood supply of the digital tendon was in the form of longitudinal vascular bundles, while the transverse anastomotic branches were short and sparse. The non-synovial region of the tendon was covered by paratenon and the vascular distribution of this region was uniform. In the synovial sheath, the blood vessels distributed only on the dorsal side, while the volar side was devoid of vessels. The profundus and superficialis tendons had an avascular zone at the proximal interphalangeal and metacarpophalangeal joints respectively. It was considered that the difference of the vascular architecture might be related to the mechanical force to which the tendon was subjected. The nutrition of tendon was discussed and the selection of tendon graft at operation was suggested.

Hand↗
PubMed1990

Immunomodulation of musk-moxa-string therapy in patients with scrofula.

The effects of musk-moxa-string therapy on the immune system in man were investigated in 39 patients with scrofula. Before treatment, the numbers of peripheral blood (PB) CD3+ and DC4+ cells and the ratio CD4+/CD8+ were found to be lower in patients with scrofula than in normal subjects, while those of B cells and DR+ cells were higher. Response of peripheral blood mononuclear cells (PBMC) to phytohemagglutinin (PHA) diminished in patients with scrofula. At month 2-6 of musk-moxa-string therapy the number of PB CD8+ cells showed slight diminution along with significant increases in CD3+ and CD4+ cells and CD4+/CD8+ ratio in total lymphocytes (P less than 0.001). In vitro a marked increased blastogenic response to mitogen stimulation with PHA was observed in PBMC of patients with scrofula after treatment (P less than 0.001). In contrast, B lymphocytes, monocytes, DR+ cells and blastogenic response to concanavalin A and pokeweed mitogen were not influenced by musk-moxa-string therapy.

Adult↗
PubMed1990

Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: II. Preparation and characteristics of monoclonal anti-isotypic antibodies to IgM from B chronic lymphocytic leukemia.

Five hybridomas producing McAbs against human serum IgM-isotype were obtained by fusing the myeloma NS-1 cell and the BALB/C murine spleen cell which had been immunized by serum IgM of patient with B chronic lymphocytic leukemia (B-CLL). These McAbs only reacted with human IgM, not with other immunoglobulins in ELISA and immune double diffusion test. An approximate positive rate of peripheral blood lymphocyte (PBL) was got when these McAbs and the McAbs against B cell were tested by indirect immunofluorescent assay. The positive rate was similar to that obtained by direct immunofluorescent test. Immunoblotting showed that the molecular weight of the antigen to these McAbs was 70-90 Kd, indicating that the antigen was IgM. The practical value of the McAbs against human IgM was also discussed.

Animals↗
PubMed1990

[A study on distribution characteristics of viral hepatitis and preventive strategy in Hangzhou].

By using the method of predictive survey, 1248 cases of acute viral hepatitis, which have been definitely diagnosed, in urban district, water-net areas, semi-mountainous and mountainous areas in Hangzhou were studied for the epidemiology and serum pathogenic typing in 1987. As a result, with the mixed infection of hepatitis A and hepatitis B at the rate of 1.20%, hepatitis A 69.71%, hepatitis B 7.13% non A non B hepatitis amounted to 21.96%. In urban and rural area, the percentage of hepatitis A ranked first while that non A non B hepatitis did second. The main risky factors in epidemicity of hepatitis A were: 1) the use of commode; 2) contact with the patients with hepatitis; 3) drinking unboiled water. Hepatitis A and hepatitis B transmitted mainly in the way of extra-intestines. Seeing dentist was the main risky factor. The relevant strategy was presented on the bases of the above-mentioned data.

Adult↗
PubMed1990

[Decompensation of physiologic hypocalcemia in infants inducing vitamin D deficiency rickets].

43 infants taking the same dosage of vitamin D and calcium were investigated. The results showed that vitamin D deficiency rickets (VDR) were still present in some infants when vitamin D was sufficient, because of deficiency of 1,25-dihydroxyvitamin D (1,25-(OH)2D3). Serum calcium, phosphorus, alkaline phosphatase, triiodothyronine (T3), thyroxine (T4), calcitonin (CT), immunoreactive parathyroid hormone (iPTH), and 25-hydroxyvitamin D (25 OHD3) concentrations were compared among infants with normal, VDR of the early and recovering stages. The decompensation of physiological hypocalcemia in infants is probably the real cause of VDR and the decompensation is correlated closely with the development of parathyroid gland. This new concept is raised both at home and abroad. More practical methods for the treatment and prevention of VDR are suggested.

Calcifediol↗
PubMed1990

[An identification method for mineral drugs].

This paper is a report on a method for chemical identification of 58 mineral drugs. Combined with the Chinese traditional identification, the method can differentiate the sham and genuine drugs in a few minutes.

Drug Contamination↗
PubMed1989

Studies on biological characteristics and modulating factors of long-term cultured bone marrow cells of a myeloma patient in vitro.

In the present study we cultured in vitro bone marrow cells from a patient with multiple myeloma (IgD) and researched into the modulation of supernatant media of various leukemic lines on the growth of culture cells. Cells in the cultures were studied for their morphological, biochemical, immunological and ultrastructural features. Drug sensitivity assay was also performed. The results showed that supernatant media of 6 cell lines promoted cell growth, but most remarkable stimulating activity was displayed by supernatant media from U937 and CEM. Cell cloning effect attained to more than 90%. Cultured cells possessing biological characteristics of malignant cells were probably malignant cells from B cell lineage. This study indicated that long-term cultures of marrow cells might provide a tool useful for clinical and laboratory purpose and a method for studies on pathogenesis, regulation of hematopoiesis, cell differentiation and guide-way drugs.

Antibodies, Monoclonal↗
PubMed1989

Studies on monoclonal anti-idiotypic antibodies to human B cell leukemia.

Murine immunocytoma cell line, NS-1, was fused with spleen cells of Balb/C mice which had been stimulated by tolerogenic disaggregated human gamma globulin and immunized by purified serum IgM from the patient with chronic B cell leukemia (B-CLL). 10 hybridoma cell lines secreting monoclonal anti-idiotype (anti-Id) antibodies to human CLL were obtained. The McAbs were subclasses belonging to IgM and of IgG mouse. Specificity and biologic characters of the monoclonal anti-Id antibodies from culture fluid or ascites were assayed by ELISA, indirect mixed ELISA sandwich, ELISA inhibition, immunofluorescence (IF) and IF inhibition. The study also proved that monoclonal anti-Id antibodies could react with homologous IgM, but not with Ig from normal donors or a panel of patients with myeloma. The results of IF and IF inhibition assay showed that monoclonal anti-Id antibodies were bound to lymphocytes of patient with B-CLL. Their reactivity was inhibited by homologous IgM, but not by lymphocytes of patients with ALL or lymphoma. Monoclonal anti-Id antibodies were heterogenous reactive patterns with cell lines in vitro.

Animals↗
PubMed1989

Studies on lymphocyte subpopulations and NK cell activities in epileptic patients.

The subpopulations of T lymphocytes, B lymphocytes and macrophages of the peripheral blood in 58 cases of epilepsia were studied with McAb by IFA method. The activity of natural killer (NK) cells of peripheric blood monocyte was investigated by 51Cr-releasing method. 22 healthy donors of about the same age served as controls. The results showed that the percentage of T3 and T4 lymphocytes in epileptic patients was decreased, and the ratio of T4/T8 was markedly reduced as compared to control group. The percentage of T8 lymphocytes was increased. There were no significant changes in B lymphocytes and macrophages. The NK cell activity also showed decrease. The results suggested abnormality in cellular immunity in epilepsia, which may be involved in the pathogenetic mechanism of the disease.

Adolescent↗
PubMed1988

The relationship between structural features of peripheral nerves and suture methods for nerve repair.

Based on techniques for identifying and distinguishing motor, sensory, and mixed fasciculi in peripheral nerves, the authors propose guidelines for selecting suture methods for nerve repair. When many mixed fasciculi are known to exist at the nerve lesion, epineurial repair is preferable; fascicular (perineurial) repair is more suitable when pure motor and sensory fasciculi are clearly recognized. Generally, epineurial repair is indicated for more proximal injuries, with fascicular repair most appropriate for more distal sites. A greater ratio of epineurial connective tissue to intrafascicular nervous tissue implies an inclination toward fascicular repair.

Acetylcholinesterase↗
PubMed1988

The effect of progestin on rabbit endometrial aromatase activity.

The ability of rabbit endometrium to synthesize estrogen was investigated. Aromatase activity was measured by incubating the viable tissue fragments with [3H] testosterone at 37 degrees C and quantitated the [3H]estrogens at the end of 6 h incubation. The activity was not detectable in endometrium and myometrium of non-pregnant rabbits. In pregnant rabbit, the activity increased from 2 to 12 fmol/h/g of tissue in endometrium obtained from both gravid and nongravid uterine horns 4-8 days after mating. Aromatase activity in endometrium at implanted sites on the 8th day after mating reached up to 550 fmol/h/g of tissue. Hormonal regulation of the aromatase activity was studied directly in cultured rabbit endometrial stromal cells. Both progesterone and medroxyprogesterone acetate stimulated the activity with 2- to 25-fold increase over the control values (0.2-1 fmol/h/mg protein). The stimulation of aromatase activity by progestin was found to be both time- and dose-dependent. Estrogen, Bu2cAMP, forskolin, HCG or relaxin had no effect on the activity. Aromatase activity in glandular epithelial cells was neither detectable nor affected by progestin. These results indicate that aromatase activity in rabbit endometrium is concentrated in stromal cells and progestin stimulates the activity. However, estrogen, forskolin and relaxin which enhanced the stimulation of the activity by progestin in human endometrium had no effect on aromatase in rabbit endometrium. The increase of aromatase activity observed after the onset of conception may be physiologically important to increase the local estrogen content for decidualization of the endometrium.

Animals↗