Biomedical subjects
Publications and source records attributed to S Zhou.
The protective effect of total flavonoids of Radix Astragali (TFA) on V79 cell damage caused by H2O2-Fe2+ system has been studied. The results show that total flavonoids of Radix Astragali inhibit lipid peroxides and increase SOD activity. It has also been found that TFA has different protective effect against various damages of V79 cells caused by hydroxyl radical.
Seven cases of human extrinsic laryngeal muscles were studied to determine the electrical activities during phonation, coughing, swallowing, fixation of thorax and respiration. The activities of these muscles all fired during phonation which were synchronous with discharge of the thyroarytenoid muscle (TAM) and increased with increasing volume of voice. They also fired during cough reflex and sphincteric action of larynx, and were basically synchronous with the TAM. They were weak during normal respiration. Although stronger electrical activities were recorded during inspiration in dyspnea, they were weaker than discharge during phonation, cough reflex and sphincteric action of larynx.
OBJECTIVE: To determine the relative frequencies of HIV-1 p24 antigen and culture positivity in white and black patients. DESIGN: Volunteers in the US military's HIV natural history study were 46% white, 44% black, 7% Hispanic and 3% other. Focusing on the comparable groups of whites and blacks, a retrospective analysis was performed of the results of virologic assays collected over a 2-year period. METHODS: p24 antigen was quantitated in sera with and without immune complex dissociation (ICD); viral isolation was performed by coculture of peripheral blood mononuclear cells. RESULTS: Results of the two virologic assays were very similar in the two racial groups, both overall and after stratification by CD4 cell count. As reported previously, the concentration of serum immunoglobulin G was found to be greater in black than white subjects. In contrast to results with ICD, sera tested without ICD resulted in differing (higher) rates of antigenemia in whites than blacks (P = 0.002). CONCLUSIONS: The frequencies of p24 antigen and culture positivity were found to be independent of race. Previously observed racial differences in antigen positivity were likely to be due to more extensive antibody binding in blacks than in whites.
Lymphatic metastasis is one of the most important problems in the treatment of gynecologic malignancy. We conducted a preliminary investigation on the feasibility and practicality of chemotherapy against lymphatic metastases of gynecologic cancer via pelvic retroperitoneal cannulation. 5-FU mixed with Isovist-300 was injected into the pelvic retroperitoneal space. X-ray films revealed that the external iliac, hypogastric, obturator, deep inguinal and most of the common iliac lymph nodes were submerged in the 5-FU solution. 5-FU concentrations in the lymph nodes were measured by high pressure liquid chromatography, which showed that 5-FU concentration of the study group was 2 to 10 times that of the control group. Pathologic findings revealed that most of the metastatic cancer cells in the study group showed obvious degeneration and necrosis while no changes were observed in the control group. No major complications or adverse effects were observed. Our results suggest that this method may be used to treat the lymphatic metastases of gynecologic cancer.
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In a sample of censored survival times, the presence of an immune proportion of individuals who are not subject to death, failure, or relapse, etc., may be indicated by a relatively high number of individuals with large censored survival times. We summarise some recent theoretical work which justifies analogues of the usual model fitting and testing techniques for such data. In particular, we discuss a 'boundary' test for the presence of immunes in the population and goodness of fit tests for parametric descriptions of the data. The methods are illustrated on some data on the relapse times of leukemia patients.
Experiments were performed on 33 white male rabbits anaesthetized with chloralose and urethane under artificial ventilation. The results were as follows: (1) depressor response could be evoked by electric stimulation of caudal ventrolateral medulla (cVLM). The inputs of deep peroneal nerve (DPN) could inhibit partly the depressor response evoked by electric stimulation of cVLM (P < 0.001). The regulation effects of DPN disappeared in 25-30 min. (2) after iv naloxone (1.5 mg/kg) or microinjection of naloxone into rostral ventrolateral medulla (rVLM) (2 micrograms/1 microliter NS), the inhibitory effect of DPN inputs was abolished partly (P < 0.01, P < 0.001). These results suggest that: (1) the depressor response elicited by cVLM excitation in rabbits can be regulated by inputs of DPN; (2) opiate peptide in rVLM may take part in the inhibitory effect of DPN inputs on depressor response excited by cVLM.
UNLABELLED: 129 PMN-samples from the peripheral blood of 70 burnt patients were collected, and ICBA, SG and O2- were dynamically studied. The harmful effects on patients' plasma on normal human PMN, and specific blocking effect of anti-human C3. C5 serum (AHC3C5S) on the above harmful effects were also observed. THE RESULTS: 1) All the parameters values showed a significant decrease in seriously or moderately burnt patients as compared with normal values; the decrease was most marked on 1st-6th postburn days when deep burn surface exceeded 45%. 2) ICBA was significantly correlated with SG and O2-. 3) Patients' plasma greatly reduced the reserves of ICBA, SG and O2- in normal PMN, while AHC3C5S might lessen the reduction in term of net reserve rates: ICBA (67.33) > SG (51.60) > O2- (46.68). The findings suggest: ICBA levels are reversely related with DBSA and fragments of C3 and C5 are the main factors in reduction of ICBA.
HBV antigens (HBcAg, HBsAg and HBeAg) in 246 cases of renal biopsy specimens with various types of glomerulonephritis were examined by immunohistochemical techniques. Southern blot hybridization was used to detect HBV DNA in 18 cases. The results showed that HBV antigens were frequently found in the tubular cells in addition to the appearance of HBV antigens on the glomeruli of certain glomerulonephritis. The positive rte of HBcAg in the tubular cells was 21.54%, which is higher than that of glomeruli (10.98%). Renal HBV DNA was positive in 15 cases and among them HBcAg expression in renal tissue in 14 cases and HBV antigenemia in 12 cases. The results suggest that HBV may also be implicated in the pathogenesis of certain cases of glomerulonephritis and the appearance of HBV antigen antibody immunocomplex in renal tissue, aside from originating in the circulation, there is the possibility of it originating from renal cells in situ.
OBJECTIVES: To analyse quantitatively the effects of clomiphene citrate (CC) on histological characteristics of proliferative endometrium. METHODS: Endometrium biopsies were performed on day 12th of both natural and CC cycles in 14 infertile patients. Nuclear size, shapes and DNA contents of epithelial and glandular epithelial cells, stromal cells were measured or calculated after HE and Feulgeu staining by computerized image analysis technique. Results were compared before and after CC treatment. RESULTS: The average area, girth and maximal diameter of the nucler of glandular and epithelial cells in CC cycles were significantly smaller than those of natural cycles (P < 0.05), while the shape factor of stromal nuclea in CC cycles was larger than the natural ones (P < 0.05). DNA contents of glandular, epithelial and stromal nuclea in CC cycles were also smaller than those of natural cycles (P < 0.02). The difference of nuclear DNA content between the 2 cycles was positively correlated with the difference of nuclear area of glandular and epithelial cells (P < 0.01). CONCLUSIONS: CC treatment inhibited the endometrial mitosis and proliferation. This effects may begin at the stage of DNA synthesis, therfore DNA contents of endometrial glandular and stromal nuclea also decreased. The action of CC may be related to estrogen receptor synthesis.
The main trunk of ansa cervicalis was anastomosed to the adductor division of the recurrent laryngeal nerve in seven patients to reinnvervate the vocal cord for unilateral vocal cord paralysis. Although the reinnervated vocal cord neither abducted nor adducted, it presented itself in midline for precise apposition with the nonparalyzed cord. Normal phonatory quality was achieved after the procedure. Electroacoustic analysis indicated that this technique might produce normal phonatory function in paralyzed larynx. Laryngeal electromyography demonstrated that the procedure seemed to induce satisfactory reinnervation of the adductor musculature. Therefore, we think this technique may be recommended as an alternative to Teflon injection or thyroplasty in selected cases.
RNA polymerase I and II transcription factors SL1 and TFIID, respectively, are composed of the TATA-binding protein (TBP) and a set of TBP-associated factors (TAFs) responsible for promoter recognition. How the universal transcription factor TBP becomes committed to a TFIID or SL1 complex has not been known. Complementary DNAs encoding each of the three TAFIs that are integral components of SL1 have not been isolated. Analysis of subunit interactions indicated that the three TAFIs can bind individually and specifically to TBP. In addition, these TAFIs interact with each other to form a stable TBP-TAF complex. When TBP was bound first by either TAFI110, 63, or 48, subunits of TFIID such as TAFII250 and 150 did not bind TBP. Conversely, if TBP first formed a complex with TAFII250 or 150, the subunits of SL1 did not bind TBP. These results suggest that a mutually exclusive binding specificity for TBP intrinsic to SL1 and TFIID subunits directs the formation of promoter- and RNA polymerase-selective TBP-TAF complexes.
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The stimulation of the production of haptoglobin from the human hepatoma HepG2 was used as a model to examine the kinetics of a cellular response to interleukin 6 (IL-6). It was demonstrated that IL-6 upregulated the production of haptoglobin in a time-dependent manner: using a sensitive radioimmunoassay for haptoglobin, increases were already detectable 2 hr after IL-6 treatment began. The haptoglobin level continued to rise in a linear fashion to at least 16 hr. The stimulation of haptoglobin by IL-6 was abolished in the presence of 5 micrograms/ml actinomycin D and was thus likely pretranslational. It was further demonstrated that the upregulation of haptoglobin continued well after the removal of IL-6 from the system. An 8-hr "pulse" of IL-6 gave rise to haptoglobin secretion which was above control levels for the following 4 days. The effects of IL-6 in vivo can therefore be predicted to be long-lived despite its own short half-life, especially since the products of IL-6 stimulation, e.g., immunoglobulin and acute-phase proteins, are themselves long-lived in the circulation.
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Cylindric titanium implants treated with bovine bone morphogenetic protein (bBMP) (Group I) and with bovine serum albumin (BSA) (Group II) were implanted in the edentulous mandibles of 15 adult dogs. They were examined 1, 2, 4, 8, and 12 weeks after insertion of the implants by scanning electron microscopy (SEM). In all specimens from Group I, active bone formation had occurred between the implant and host bone, with a well-adapted fit between the implant and the newly formed bone 4 weeks after implantation. The surrounding bone was of normal structure by week 8. However, 3 months after implantation, fibrous tissue was consistently seen surrounding parts of the implants in Group II. The results of this study suggest that the implants treated with bBMP are capable of forming new bone of normal structure at a faster rate than BSA controls and that this new bone is closely adapted to the implant surface.
This investigation assessed the thermoregulatory impact of performing simulated tasks normally encountered during chemical accident clean-up while wearing chemical protection clothing under various representative thermal loads. A Drager 500 (D) suit was worn with a self-contained breathing apparatus (SCBA) external to the suit, while both a Trelleborg Trellchem Super Extra (T) and a James North MZ500 (J) suit required the SCBA to be worn inside the suit. The D suit was unventilated, while the T and S suits were ventilated with the subject's exhaled air. The T suit also was ventilated via a 2 L/min flow of air from the SCBA. Subjects were six firefighters. Each simulation lasted for 30 minutes and involved tasks such as drum rolling, drum carrying, walking, and hose dragging. The trials were conducted at 11.3, 17.1, and 23.8 degrees C WBGT. The overall mean peak heart rate was 128.1 +/- 2.80 breaths/min and was elicited while performing lifting tasks. Nonsignificant differences (p > 0.05) were observed for both the average heart rate and sweat rate. Mean skin temperature, mean body temperature, and temperature within the suit cavity were significantly higher when wearing the D suit compared to wearing T or J suits; differences between the T and J suits were nonsignificant. Suit type did not significantly affect rectal temperature, which also failed to exceed the American Council of Governmental Industrial Hygienists' (ACGIH) standard of 38.0 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
Hepadnaviruses encode a single core (C) protein which assembles into a nucleocapsid containing the polymerase (P) protein and pregenomic RNA during viral replication in hepatocytes. We examined the ability of heterologous hepadnavirus C proteins to cross-oligomerize. Using a two-hybrid assay in HepG2 cells, we observed cross-oligomerization among the core proteins from hepatitis B virus (HBV), woodchuck hepatitis virus, and ground squirrel hepatitis virus. When expressed in Xenopus oocytes, in which hepadnavirus C proteins form capsids, the C polypeptides from woodchuck hepatitis virus and ground squirrel hepatitis virus, but not duck hepatitis B virus, can efficiently coassemble with an epitope-tagged HBV core polypeptide to form mixed capsids. However, when two different core mRNAs are coexpressed in oocytes the core monomers show a strong preference for forming homodimers rather than heterodimers. This holds true even for coexpression of two HBV C proteins differing only by an epitope tag, suggesting that core monomers are not free to diffuse and associate with other monomers. Thus, mixed capsids result from aggregation of different species of homodimers.