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Biomedical subjects

D Jiang

Publications and source records attributed to D Jiang.

At least 163 records · Page 9Linked to original sources
PubMed1994

[Experimental study on blocking agent of substance P nerves in the treatment of allergic rhinitis].

Experimental guinea pigs with allergic rhinitis were treated with capsaicin (CAP). During the whole course of treatment, nasal secretions, sneezing and nasal scratching were observed and recorded, as compared quantitatively with those of the control group. By means of specific radioimmunoassay, determination of the amount of substance P (SP) in the nasal mucosa was done in the treated group, untreated group and normal control group. By using the filter paper technique, the functional status of the nasal secretion was observed. The experimental group was given CAP by dripping into the nasal cavities for 15 days. The results indicated that the various symptoms of allergic rhinitis were obviously relieved. The nasal secretions were decreased by 64% as compared with those before the treatment; and SP content in the nasal mucosa was remarkably reduced in comparison with untreated group. The results of the experiment indicated: the repeated use of CAP might effectively deplete SP content in the nasal mucosa and prove the new theory of the effects of CAP on the desensitization of the SP nerves. CAP as a blocking agent of SP nerves blocked the axon reflex and exerted curative effect on allergic rhinitis.

Animals↗
PubMed1993

Event-related potentials reveal a memory trace for temporal features.

Auditory event-related potentials (ERPs) were recorded from reading subjects while they were presented with 50 ms tone pips intervened by regular silent intervals of 550 ms. This interval was occasionally shortened either to 250, 100, 25, 10, or 2 ms, which resulted in the elicitation of the mismatch-negativity (MMN), a change-specific ERP component not elicited by tones appearing after the regular, longer intervals. This indicates that the MMN is not just due to new afferent elements activated by deviant but not standard stimuli. In addition, the present results suggest that the temporal parameters of acoustic stimulation are also encoded in memory traces which therefore are representations of auditory events rather than only of static stimulus aspects.

Adult↗
PubMed1993

Decrease in cellular replicative potential in "giant" mice transfected with the bovine growth hormone gene correlates to shortened life span.

Adult mice, (C57BL/6 x Sjl)F1 hybrids, transfected with the bovine growth hormone gene (bGH) grow to twice normal size, but have a mean life span less than 50% that of control siblings without the transgene. The replicative potentials of cells from six different tissue sites (tail skin and ear skin dermal fibroblasts, tail subdermal connective tissue fibroblasts, kidney medulla epithelial cells, bone marrow myofibroblasts, and spleen myofibroblasts) were assayed in vitro using clone size distribution analysis. Cells from all of the above bGH+ tissues produced a smaller fraction of large clones, relative to age-matched controls, in all of these cell types. The loss of replicative potential did not appear to be the result of negative conditioning of the cloning media by the bGH+ cells, and was tightly correlated to the period of accelerated growth in these animals (3-12 weeks), a time when additional GH receptors are expressed.

Age Factors↗
PubMed1993

Stimulus duration and the sensory memory trace: an event-related potential study.

The mismatch negativity (MMN) of the auditory event-related potential is elicited when a stimulus deviates from that represented by the neural memory trace developed by preceding stimuli. The effect of stimulus duration on this trace was studied by presenting sequences of 1000 Hz, 80 dB stimuli to subjects engaged in silent reading. Stimuli were, in different blocks, either of 4, 10, 30, 100 or 300 ms in duration. 5% of the stimuli were deviants which were either higher in frequency (1050 Hz) or lower in intensity (70 dB) than the standards. The "silent" period between two successive stimuli was constant at 300 ms. The minimum stimulus duration with which a distinct MMN was elicited by frequency deviants was 30 ms, but the MMN amplitude was not increased when stimulus duration was further prolonged. In contrast, the intensity MMN was elicited even when stimulus duration of 10 ms and its amplitude increased as a function of stimulus duration. Reaction times and hit percentages in response to these deviant stimuli in a separate discrimination task displayed analogous patterns of results.

Adult↗
PubMed1993

Attention and mismatch negativity.

The mismatch negativity (MMN) component of the auditory event-related potential (ERP) is elicited by infrequent, physically deviant stimuli in a sequence of frequent homogeneous stimuli (standards). It has been suggested that the MMN is generated by an automatic (attention-independent) neural mismatch process with a memory trace that encodes the physical features of the standard stimulus. The proposed MMN independence of attention was addressed in the present study. Standard stimuli and two types of deviant stimuli, differing from standards either in frequency or intensity, were dichotically presented in random order and at a rapid rate. The subject attended either to left- or right-ear stimuli, counting the number of a designated type of deviants in that ear. In the present conditions of very strongly focused attention, the MMN was elicited even by frequency change in the ignored input stream, and its amplitude was very similar to that of the MMN elicited by equivalent deviant stimuli (targets) in the attended input stream. In contrast, the MMN to intensity deviation was clearly attenuated in the absence of attention. This effect is, however, probably due to the attention effect on the MMN generator itself rather than the antecedent sensory-analysis and -storing functions.

Acoustic Stimulation↗
PubMed1993

Microslicing of the resin-embedded cochlea in comparison with the surface preparation technique for analysis of hair cell number and morphology.

The surface preparation technique for hair cell counting is frequently used for the analysis of cochlear pathology in relation to hearing impairment. To overcome problems encountered with standard surface preparation methods, a new combination of resin embedding and microslicing has been applied to the mammalian cochlea, to permit hair cell counting to be followed by electron microscopic analysis. Partial removal of the cochlear shell is followed by resin infiltration under vacuum prior to polymerization. The cochlea is then subdivided into hemicoils using a mounted annular diamond blade. Embedding before microslicing ensures that both apical and basal regions of the cochlea are preserved equally well with an evenly distributed and therefore predictable 10% hair cell loss. By comparison, the standard surface preparation method often produces distortion of remaining organ of Corti and unpredictable losses of hair cells, for example, up to 17%. The damage tends to be greatest towards the base of the cochlea, an area which shows particular susceptibility to ototoxic agents such as the aminoglycoside antibiotics. Thus, for assessment of pathology caused by ototoxic agents, this method has considerable advantages over the surface preparation technique.

Animals↗
PubMed1993

SV40 T antigen abrogates p53-mediated transcriptional activity.

Recent evidence suggests that the tumor-suppressor protein p53 functions as a transcriptional regulator to control cell proliferation. An interaction with p53 is required for SV40 T antigen to transform primary cells; however, the effect of T antigen binding on p53 function is not known. In order to determine if an interaction with T antigen results in loss of p53-mediated transcriptional activity, we have used vectors expressing either a p53-GAL4 fusion protein or a wild-type p53 protein in transient co-transfection assays with T-antigen expression vectors. We have demonstrated that coexpression of T antigen significantly reduces both p53-GAL4-mediated transcription from a GAL4-dependent CAT reporter and p53-mediated transcription from a consensus p53 binding site in vivo. Moreover, T antigen was able to reduce binding of p53-GAL4 to its GAL4 binding sequence in gel shift experiments in vitro. These observed activities of T antigen were all dependent upon a functional p53-binding domain. In addition, coexpression of human papillomavirus type 18 E6 protein, able to bind to p53, was able to significantly reduce p53-mediated transcription. These results suggest that an interaction of certain viral oncoproteins with p53 results in loss of transcriptional activity of p53, a function that is important for maintaining normal cell growth.

3T3 Cells↗
PubMed1992

Immune response to Moloney murine leukemia virus nonviral, tumor-associated antigens fails to provide in vivo tumor protection.

Two distinct populations of CTL have previously been shown to be generated in lymphocyte cultures derived from the spleens of C57BL/6 mice that have rejected Moloney murine leukemia virus:Moloney sarcoma virus (MoMuLV:MSV)-induced tumors. One population is specific for MoMuLV viral Ag whereas the other appears to be directed against a nonviral, tumor-associated Ag (TAA). Using a virus-negative variant of the MoMuLV-induced lymphoma MBL-2 that has retained the expression of the MuLV:TAA, we attempted to further characterize the MuLV:TAA-specific CTL population. First, this same pattern of CTL reactivity was observed using a variety of immunization protocols indicating that the TAA-specific CTL population was not an artifact of the original immunization protocol but was a reproducible component of the MoMuLV CTL response. Moreover, CTL precursor frequency analysis indicates that the MuLV:TAA-specific CTL represent approximately 60% of the CTL detected in in vitro cytotoxicity assays. However, when the role of MuLV:TAA CTL in the in vivo rejection of MoMuLV-induced tumors was examined, no role for the MuLV:TAA-specific CTL response could be determined. Immunization protocols that had been shown to give rise to both CTL populations were capable of protecting mice from tumor development after a challenge with the parental MBL-2 tumor cell line but not the virus-negative variant MBLv cell line. In addition, immunization with the variant, shown to give rise to only MuLV:TAA-specific CTL capable of lysing both MBL-2 and MBLv in vitro, failed to protect mice from a tumor challenge of either cell type.

Animals↗
PubMed1992

Perioperative risks and safety of surgery for severe obesity.

The National Bariatric Surgery Registry (NBSR) results reflect low perioperative risk for obesity surgery. Five deaths occurred within 40 d of operation in 5178 patients (0.1%). A subset of 3174 patients with complete information for complication and postoperative hospital stay was further studied. Females comprised 87% of the data set. Median values were determined for age, 37 y (18-70 y); operative weight, 121 kg (77-288 kg); and operative body mass index (BMI), 44 kg/m2 (29-91 kg/m2). Patients with no complications (89.7%) were reported to have a median postoperative stay of 4 d (2-23 d). The most severe complications were deep venous thrombosis (0.3%) and gastrointestinal leak (0.6%), with median postoperative hospital stay of 12 d (ranges 2-27 and 4-59 d, respectively). The most frequent complication reported was respiratory (4.5%), with median postoperative stay of 6 d (3-34 d). Median postoperative hospital stay for wound infection (1.6%) was 5 d.

Adolescent↗
PubMed1992

Predictors of Two Obesity Complications: diabetes and hypertension.

Gender, age, waist-hip ratio (WHR) and body mass index (BMI) have been reported to herald two complications of obesity: diabetes or hypertension. Most literature is based on patient populations with mean BMIs ranging from 22 to 35 kg/m(2). This study population of severely obese patients selected for surgical treatment of obesity had a mean age of 37 +/- 9.4 years, median WHR of 0.9 (0.4-2.1) and median BMI of 44.0 (29-89) kg/m(2). It was found that age, WHR and BMI were significant predictors for diabetes or hypertension. Gender was not found to be a significant predictor for either diabetes or hypertension. A mathematical model was used to calculate the predictive probability of developing diabetes or hypertension using age, BMI and WHR.

Journal Article↗
PubMed1992

[The segmental distribution of the afferent neurons of the "zusanli" point and the caecum in rabbits--a study with the horseradish peroxidase method].

Ten adult rabbits were used in this experiment. A solution of 10-20% HRP (sigma IX, RZ = 3.2) was injected into the "Zusanli" point and the subserosa of the caecum. The uptake and retrograde transmission of HRP in the afferent neurons of both the somatic and visceral nerves were traced to the spinal ganglia. The results showed that: 1. Labelled afferent neurons from the region of "Zusanli" point were found in the spinal ganglia T12-S2 with a higher concentration in L4-S2. 2. Labelled afferent neurons from the region of the caecum were found in the spinal ganglia T2-S2 with a higher concentration in T12-L2. 3. The ranges of distribution of labelled afferent neurons from the regions overlapped in the segments T12-S2.

Acupuncture Points↗
PubMed1992

[Observation on 63 cases of facial paralysis treated with acupuncture].

Sixty-Three cases with facial paralysis were treated mainly by acupuncture combining with point injection. The main points selected were Yangbai (GB14), Wai Jingming (BL1), Sibai (ST2), Yingxiang (LI20), Dicang (ST4), Jiache (ST6), Quanliao (ST18) and Qianzheng. The points were used alternatively. Auxiliary points: for type of deficiency of both qi and blood, Zusanli (ST36), and Sanyinjiao (SP6) were added: for type of disharmony between Ying and Wei, Fengchi (GB20) and Hegu (LI4) were added; for type of stagnancy of qi and blood, Weiguan (TE5) and Taichong (LR3) were added; for type of wind-heat stagnating collaterals, Yifeng (TH17) and Yanglingquan (GB34) were added. 10 out of 60 cases, which showed no remarkable effectiveness after two courses, injection of vitamin B1 and vitamin B12 to facial points combined with Hegu (LI4) point on opposite side was performed. Therapeutic results: 31 cases (49.2%) were cured, 15 cases (23.8%) markedly effective, 16 cases (25.4%) effective and 1 case (1.6%) ineffective.

Acupuncture Points↗
PubMed1992

[Mechanism of neuronal damage caused by cerebral ischemia].

After the middle cerebral artery of rats was occluded, changes in the content of 14 free amino acids and the activity of antioxidant enzymes in the ischemic striatum were assessed with respect to the duration of ischemia. Glu and Asp levels were significantly reduced by 60 min of ischemia, GABA was increased by 30 and 60 min and Ala was increased by 5, 15, and 30 min. During ischemia, the levels of striatal Gln, Asn, Ser, Tau, Gly and Pro were found to be normal. In comparison with the sham-operated rats, the changes in the content of Thr, His, Arg and Tyr were inconclusive, since the effect of operative stress could not be ruled out on such occasion. Concomitantly, the Zn-Cu superoxide dismutase and glutathione peroxidase activity were significantly reduced by 30 min of ischemia. It revealed that the reduced capacity to scavenge the oxygen free radicals occurred during the early stage of cerebral ischemia. The above changes of Glu, Gln, GABA and Pro level might be considered as the final outcome of the decrease of glutamate synthesis, the acceleration of its conversion to GABA, and the extracellular leakage of glutamate. According to our data, the oxygen free radicals might be involved in the evolution of primary neuronal damage at the ischemic striatum.

Amino Acids↗
PubMed1992

An age-related reduction in the replicative capacity of two murine hematopoietic stroma cell types.

Two stromal cell types, myofibroblasts and endothelial-like cells, that were identifiable by structural and antigenic specificities, were obtained from murine bone marrow and spleen of young, middle-aged, and old mice of two strains and sexes and grown in liquid culture for 9 or 10 days. As expected, there were more total nucleated cells per organ in the old mice (with larger organs) than in the young mice. However, the concentration of stromal colony forming cells was greater in the young mice, resulting in the number of colony forming cells per organ not being significantly different in most comparisons. The in vitro replicative capacity of the two stromal cell types from both organs in all age groups was determined by clone size distribution assays. In all instances the number of cell doublings achieved was statistically significantly greater in the stromal cell clones from young mice than those from old mice. The cell doubling capacity of the middle-aged mice fell between that of the young and the old mice and in most instances that difference was also statistically significant. It was concluded that these in vitro findings constituted a biomarker of aging in these tissues and that this was significant in relation to previous in vivo and in vitro work by these authors and by others reporting the inferiority of aged bone marrow and spleen stroma to regenerate and to support hematopoiesis.

Aging↗
PubMed1992

[Epilepsy and hypohaptoglobinemia].

The serum haptoglobin (Hp) of 24 patients with familial epilepsy and 21 relatives of them, as well as 21 patients with secondary epilepsy was determined by the method of linear concentration gradient (4-22%) polyacrylamide gel electrophoresis. The mean value of their serum Hp was significantly reduced to 54.83% (P less than 0.001), 76.48% (P less than 0.01) and 74.91% (P less than 0.01) of that of the control (109.63 mgHb/dl, n = 201) respectively. The possible pathophysiological mechanism of the epileptic seizures and reduced serum Hp level was discussed briefly.

Epilepsy↗
PubMed1991

Weight Loss Curve Analysis.

The purpose of this study was to develop a mathematical model to describe weight loss trend over time and to determine differences, if any, among various weight loss trends. Weight change was studied following Roux-en-Y gastric bypass (RGB) and vertical banded gastroplasty (VBG). The total number of patients analyzed was 3172, 63.5% VBG and 36.5% RGB. Median age (years) for VBG was 36 (range 18-70) and RGB 38 (range 18-66). Median operative body mass index (BMI) (kg/m(2)) for VBG was 45.0 (range 30.1-90.5) and RGB 43.3 (range 30.4-80.6). Females represented 87% of the VBG patients and 89% of RGB patients. Obesity category percentages for each operative type were: super-VBG 20%, RGB 14%; morbid-VBG 78%, RGB 80%; obese-VBG 2%, RBG 6%. The development of a mathematical model to study weight loss over time was a two-stage process. First, weight loss trend was determined as evidenced by individual patient BMI values plotted over time. It was observed that plots represented quadratic curves, so the model BMI = B&inf0; + B&inf1;(time) + B&inf2;(time)(2) was used. Second, the estimated beta's (B&inf0;, B&inf1;, B&inf2;) were treated as response variables to estimate weight loss trend for the combination effect of three independent variables: gender (male and female), obesity category (super, morbid, obese) and operative type (VBG and RGB). It was found that the three independent variables simultaneously interact with patient weight loss (p = 0.0001).

Journal Article↗
PubMed1991

The association between pregnancy and human papilloma virus prevalence.

This study examined the effects of pregnancy on the prevalence of HPV infection, comparing 69 pregnant and 54 nonpregnant age-frequency matched female patients. HPV prevalence was detected by DNA hybridization using the ViraPap/ViraType dot blot procedure. The prevalence of HPV among pregnant women increased with gestational age from 8.0% in the first trimester, to 16.7% in the second, and 23.1% in the third trimester. This finding suggests that HPV infection may be activated by hormonal or other effects of pregnancy and may explain why number of pregnancies is known to be associated with increased risk of cervical dysplasia and cancer. Oncogenic HPV types 16/18 and 31/33/35 were identified with almost equal frequency in the study population whereas HPV 6/11 was seen rarely. The logistic regression models indicate that there were no significant differences between HPV positive and HPV negative groups by age, income, number of sex partners, age of first intercourse, average frequency of intercourse per month, number of pregnancies, oral contraceptive duration, or pregnancy status. There were no interaction effects. A current Pap result of cervical dysplasia (OR = 8.9; 95% confidence interval: 2.1, 38.8), oral contraceptive use (OR = 0.1; 0.03, 0.6), and education (OR = 1.4; 1.1, 1.8) were significant predictors of HPV status.

Adolescent↗