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Biomedical subjects

S Jiang

Publications and source records attributed to S Jiang.

At least 199 records · Page 11Linked to original sources
PubMed1998

Iontophoresis itself on hairless mouse skin induces the loss of the epidermal calcium gradient without skin barrier impairment.

Iontophoresis increases the delivery of drugs across the stratum corneum, but the pathway by which ionized drugs transit the stratum corneum is unknown. In this study we examined the effect of iontophoresis on the skin barrier and the epidermal calcium gradient. Hairless mice were subjected to iontophoresis for 5-120 min and skin specimens were prepared for electron microscopy. Neither positive nor negative iontophoresis affected transepidermal water loss. Lacunar dilatation and partial distention of the intercellular layers of the stratum corneum were observed in rough proportion to applied time in iontophoresis skin as well as control skin. Additionally, using calcium capture cytochemistry, we demonstrated that both positive and negative iontophoresis caused the disappearance of the epidermal calcium gradient with marked decrease in calcium content in the upper epidermis. Positive iontophoresis was associated with increased calcium in the stratum basale and dermis, whereas negative iontophoresis increased calcium in the stratum corneum. Moreover, as previously shown after barrier disruption and sonophoresis, the decrease in calcium content in the upper epidermis was associated with an increase in lamellar body secretion and the build up of lamellar material at the stratum corneum-stratum granulosum interface. In conclusion, iontophoresis on the skin of hairless mice may induce the change of ionized molecules in the epidermis, as the loss of the calcium gradient, which causes the decrease of skin impedence, gives charged drugs the ability to cross the skin more easily. Also, the structural changes, such as lacunar dilatation, whether they result from hydration or occlusion, may help the transport of charged drugs across the stratum corneum.

Animals↗
PubMed1998

Effects of impulse noise on cortical response threshold and inner ear activity of succinic dehydrogenase and acetylcholinesterase in guinea pigs.

The effects of impulse noise (firecrackers at 170 dB SPL, 1, 10, 20 rounds) on auditory cortical response threshold (CRT) and activity of succinic dehydrogenase (SDH) and acetylcholinesterase (AchE) in the inner ear were studied in 37 guinea pigs. The results showed that extent of damage in the cochlea was related to amount of exposure to the noise. Exposure to 10 rounds resulted in temporal threshold shift (TTS); to 20 rounds the result was permanent threshold shift (PTS). For the period when TTS existed, inverse correlation was noticed between enzyme activity change and CRT shift. The correlation could not be established when PTS was induced. The results suggest that the pathomechanism of PTS was more complex than that of TTS. The significance of the results is discussed.

Acetylcholinesterase↗
PubMed1998

A conformation-specific monoclonal antibody reacting with fusion-active gp41 from the human immunodeficiency virus type 1 envelope glycoprotein.

The gp41 subunit of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein plays a major role in the membrane fusion step of viral infection. The ectodomain of gp41 contains a six-helix structural domain that likely represents the core of the fusion-active conformation of the molecule. A monoclonal antibody (MAb), designated NC-1, was generated and cloned from a mouse immunized with the model polypeptide N36(L6)C34, which folds into a stable six-helix bundle. NC-1 binds specifically to both the alpha-helical core domain and the oligomeric forms of gp41. This conformation-dependent reactivity is dramatically reduced by point mutations within the N-terminal coiled-coil region of gp41 which impede formation of the gp41 core. NC-1 binds to the surfaces of HIV-1-infected cells only in the presence of soluble CD4. These results indicate that NC-1 is capable of reacting with fusion-active gp41 in a conformation-specific manner and can be used as a valuable biological reagent for studying the receptor-induced conformational changes in gp41 required for membrane fusion and HIV-1 infection.

Amino Acid Sequence↗
PubMed1998

Regulation by uniconazole-P and gibberellins of morphological and anatomical responses of Fraxinus mandshurica seedlings to gravity.

The present study deals with roles of gibberellins (GAs) in gravitropic responses of woody stems of horizontally-positioned, 2-year-old seedling of Fraxinus mandshurica Rupr. var. japonica Maxim. The application of uniconazole-P, an inhibitor of GAs biosynthesis, to stem nodes at various concentrations significantly inhibited not only righting the stems but also wood formation. The application of GAs (GA3 and GA4) in combination with uniconazole-P negated the inhibitory effect of the treatment of uniconazole-P alone. The GAs alone did not affect wood formation, however, both GAs increased wood formation on both the upper and lower sides of horizontal stems with an increase in the concentration of combined uniconazole-P. In all of the seedlings, tension wood was formed on the upper side of stems. The application of uniconazole-P alone at various concentrations did not inhibit the formation of tension wood fibres.

Dose-Response Relationship, Drug↗
PubMed1998

Modulation of cytokine production by dehydroepiandrosterone (DHEA) plus melatonin (MLT) supplementation of old mice.

Tissue levels of the antioxidants melatonin (MLT) and dehydroepiandrosterone (DHEA) decline with age, and this decline is correlated with immune dysfunction. The aim of the current study is to determine whether hormone supplementation with MLT and DHEA together would synergize to reverse immune senescence. Old (16.5 months) female C57BL/6 mice were treated with DHEA, MLT, or DHEA + MLT. As expected, splenocytes were significantly (P < 0.05) higher in old mice as compared to young mice. DHEA, MLT, and DHEA + MLT significantly (P < 0.005) increased B cell proliferation in young mice. However, only MLT and DHEA + MLT significantly (P < 0.05) increased B cell proliferation in old mice. DHEA, MLT, and DHEA + MLT help to regulate immune function in aged female C57BL/6 mice by significantly (P < 0.05) increasing Th1 cytokines, IL-2, and IFN-gamma or significantly (P < 0.05) decreasing Th2 cytokines, IL-6, and IL-10, thus regulating cytokine production. DHEA and MLT effectively modulate suppressed Th1 cytokine and elevated Th2 cytokine production; however, their combined use produced only a limited additive effect.

Animals↗
PubMed1998

Selection of human anti-HAV McAb from a phage antibody library.

The phage displaying antibody fragments were subjected to three rounds of panning with hepatitis A virus (HAV) antigen in solid phase. The eluted phage was enriched nearly 100 fold, and the percentage of recombinant clones increased from 25% to 100% after three rounds of panning. The HAV antigen-specific monoclonal antibody (McAb) was screened by sandwich ELISA, and the specificity of these antibodies was further confirmed by competitive inhibition ELISA.

Antibodies, Monoclonal↗
PubMed1998

[Study on dopamine metabolite in cerebrospinal fluid of schizophrenics and epilepsics].

The concentration of dopamine (DA) metabolite-homovanillic acid (HVA) in cerebrospinal fluid (CSF) of 40 patients with schizophrenia 27 with epilepsy and 15 controls without disorders of CNS was reported. The results showed that there were no significant differences in mean levels of HVA among the three groups. It is suggested that both schizophrenia and epilepsy are not abnormal in total level of DA metabolism.

Adult↗
PubMed1998

[Expression of CD44 molecule and its significance in uveal and conjunctival melanomas].

The aim of this study was to evaluate the role of over expression of CD44 molecule in the development and progression of uveal and conjunctival melanomas. Flow cytometry (FCM) and immunofluorescence methods were used for detecting the CD44V expression in uveal malignant melanomas (UMM), conjunctival nevi (CN) and conjunctival malignant melanomas(CMM). The expression content of CD44 in 7 cases of CMM was significantly higher than that in 5 cases of CN (P < 0.05); the CD44V positive expression percentages in 7 cases of CMM and 40 cases of UMM were 71.43% and 62.50% respectively; the expression content of CD44V in UMM was related to scleral invasion (P = 0.0105); there was a negative correlation between the expression content of CD44V and proliferative index (PI), S-phase fraction (SPF) (P < 0.01; P < 0.05). The results suggested that the over expression of CD44V might be involved in the development of CMM and UMM and related to local infiltration ability of UMM and that the CD44V expression content detected by FCM might be helpful in discriminating CN From CMM, but this waited for further research confirmation.

Conjunctival Neoplasms↗
PubMed1998

[Induction of apoptosis of CD34+ cells by serum from two patients with severe aplastic anemia].

OBJECTIVE: To explore the relationship between the hematopoietic inhibitor and apoptosis of CD34+ cells in patients with severe aplastic anemia (SAA). METHODS: The inhibiting activity to the growth of both BFU-E and CFU-GM was analysed by in vitro methylcellulose culture and CD34+ cell apoptosis was assayed with a kit of programmed cell death assay and flow cytometry. RESULTS: Sera from two SAA patients suppressed the growth of normal hematopoietic progenitor cells and induced CD34+ cell apoptosis. Serum immunoglobulin fraction assay showed that the inhibiting activity was in the IgG fraction which bound specifically to CD34+ cells. CONCLUSION: There was an inhibitive IgG fraction, which induced CD34+ cell apoptosis, in the serum of SAA patients and CD34+ cell apoptosis might be a part of the pathogenesis of SAA.

Adolescent↗
PubMed1998

[The effect of endothelium-derived relaxation factor on specific property of vasomotion of cochlea in guinea pig].

By using intravital microscopy measurement with image processing system, continuous diameter changes were measured by self-tracking with computer, the present study is to investigate specific property of vasomotion in cochlear microvessels and its responsibility to the endothelium-derived relaxation factor (EDRF/NO). The results demonstrated that the vasomotion of cochlear arteriole existed in normal condition in a small pattern. It was found that the vasomotion was significantly enhanced after administration of L-arginine(which is donor of EDRF/NO), and L-arginine induces a sequence of changes in cochlear blood flow. There were significant statistic difference before and after the drug administration. The conclusion suggest that EDRF/NO play an important role in the increase of blood flow by improvement of vasomotion.

Animals↗
PubMed1998

[Study on diagnostic value of analyzing argyrophilic nucleolar organizer regions in benign and malignant pleural effusions].

OBJECTIVE: To evaluate the diagnostic value of argyrophilic nucleolar organizer regions (AgNOR) measurement in benign and malignant pleural effusions. METHODS: Pleural effusions from 50 patients with proven malignant disease, 30 patients with benign disease were studied using the one-step silver staining method. Six cytologically atypical samples were also included in this study. RESULTS: The mean AgNOR count in malignant cells was significantly higher than that in benign mesothelial cells (7.6 +/- 1.4 vs 2.3 +/- 0.7, P < 0.01). The morphological features of AgNOR in malignant cells were mainly of diffuse type (80%), while in benign mesothelial cells, mainly of nucleolar type (90%). Among the six cytologically atypical samples, four were in the malignant range, two were in the benign limits, and these were proved by histopathology. CONCLUSION: AgNOR study may be useful in differential diagnosis of benign and malignant pleural effusions.

Diagnosis, Differential↗
PubMed1998

[Preparation of novel macroporous silica-based amide-polymer-bonded packing and its application to the separation of proteins].

A novel macroporous silica-based amide-polymer-bonded packing for protein separations in HPLC is described. The macroporous silica support was bonded with diethoxymethyl vinyl silane and then copolymerized with methylacrylamide and divinylbenzene to produce a tailored stationary phase with high resolution and inertness. The repeatability of packing preparation is good. They were characterized through the application of a standard protein mixture of pepsin, glucose oxidase, bean trypsinogen inhibitor and ribonuclease. The time for elution of these proteins is less than 12 minutes. It is suggested that the macroporous silica-based amide-polymer-bonded packing can be used to quickly separate biopolymer. This packing is a better alternative for the biopolymer separation.

Chromatography, High Pressure Liquid↗
PubMed1998

[Screening for the 1555G mutation in mitochondrial DNA in pedigrees with aminoglycoside antibiotic induced deafness].

OBJECTIVE: To identify the relationship between the 1555G mutation in mitochondrial DNA and aminoglycoside antibiotic induced deafness and provide theoretical evidence for establishing diagnostic method. METHODS: Blood samples were obtained from three pedigrees with aminoglycoside antibiotic induced deafness. DNA was extracted from the isolated leukocytes. The mitochondrial DNA fragments were amplified by PCR, 1555G mutation was detected by Alw26 I restriction endonuclease digestion, allele-specific oligonucleotide hybridization and DNA sequencing. RESULTS: Seven individuals from pedigrees A and C carried homoplasmic 1555G mutation, six individuals from pedigree B did not have 1555G mutation. CONCLUSION: 1555G mutation is not the only pathologic mitochondrial DNA mutation associated with aminoglycoside antibiotic induced deafness. This is the first finding of aminoglycoside antibiotic induced deafness pedigree without 1555G mutation.

Anti-Bacterial Agents↗
PubMed1998

[Jugular bulb anomaly].

OBJECTIVE: To differentiate and treat correctly the jugular bulb anomalies, as well as to avoid the unnecessarily enlarged operations. METHODS: Four cases of jugular bulb anunalies were reported and analysed. RESULTS: Two of 4 cases were misdiognosed as jugular glomus tumors; One was considered to be jugular bulb anomaly, but was done with an enlarged operation; another one was still accompanied with benign intracranial hypertension syndrome, was inappropriately treated. CONCLUSION: The jugular bulb anomaly was often misdiagnosed, therefore the anomaly should be differentiated from the jugular glomus tumor carefully.

Adult↗
PubMed1998

[Application of three demensional reconstruction of CT in lateral cranial base surgery].

OBJECTIVE: To study the characteristics of 3D-CT of the lateral cranial base and its application in lateral cranial base surgery. METHODS: Five normal adult subjects and 10 with lateral cranial base lesions were scanned with Philips Tomoscan SR 7000 CT scanner. The scanning ranges extended from the top to the bottom of the temporal bone, including whole lesions, with bone window algorithm and contiguous serial 1.5 mm thin-cut scans in succession in axial plane. The 3D-CT reconstruction was processed in the Easy Viewing CT/MRI workstation. RESULTS: The 3D-CT reconstruction could clearly delineate the foraminan, fissures and important bony marks. The ranges of the lesions, the relationships between the lesions and the structures around them were demonstrated more clearly than 2D-CT. It was of important significance in differential diagnosis for jugular foramen lesions. 3D-CT could be used to imitate operation and design operative plan. CONCLUSION: 3D-CT was of important value in diagnosis of lateral cranial base tumors, and could be used to imitate operation and design operative plan.

Adolescent↗