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Biomedical subjects

S Jiang

Publications and source records attributed to S Jiang.

At least 235 records · Page 13Linked to original sources
PubMed1997

Minimal residual disease in acute myelogenous leukaemia and myelodysplastic syndromes: a follow-up of patients in clinical remission.

The majority of patients with acute myelogenous leukaemia (AML) and myelodysplastic syndromes (MDS) relapse, especially those with unfavourable cytogenetics. This study was designed to investigate the presence and frequency of minimal residual disease (MRD) in patients with AML or MDS (n=35) and numerical abnormalities of chromosomes 6, 7, 8, 9, 10, 17 and 18 in clinical remission by using a combination of fluorescence activated cell sorting (FACS), fluorescence in-situ hybridization (FISH) and labelling with bromodeoxyuridine (BUdR). The technique enables the detection of as few as three leukaemic cells in 10(5) normal cells. MRD was detected in 33/35 patients in complete remission (CR). 16 patients relapsed (8/11 with monosomy 7, 4/17 with trisomy 8, and 4/7 with other cytogenetic abnormalities) after a median of 4.8 months (range 3-13). Levels of MRD (P=0.007) and proliferation index (P=0.011) were significantly higher in patients with monosomy 7 than in patients with trisomy 8 or other cytogenetic abnormalities. The percentage of cells in S-phase, the number of abnormal cells and cytogenetic class were related to time to relapse (P=0.001) with S-phase being the single most important prognostic factor (P=0.0001). We conclude that the combination of FACS/FISH/BUdR, which determines the number, phenotype and proliferation rate of very rare leukaemic cells in patients with AML or MDS in clinical remission, provides information that is useful in the identification of patients with high and low likelihood of relapse.

Acute Disease↗
PubMed1997

Age and hormonal dependence of acquisition of oocyte competence for embryogenesis in prepubertal calves.

This research was designed to improve our understanding of oocyte maturation and acquisition of developmental competence of oocytes using prepubertal heifers as a model. Oocytes were collected by ultrasound-guided transvaginal oocyte retrieval from 20 age-matched calves at 5, 7, 9, and 11 mo of age that had or had not received gonadotropin stimulation. Numbers of oocytes recovered from unstimulated heifers decreased with age, being 15 +/- 2, 12 +/- 1, 7 +/- 1, and 7 +/- 1 (for 5-, 7-, 9-, and 11-mo-old calves, respectively). Corresponding numbers for the gonadotropin-stimulated heifers were 18 +/- 2, 16 +/- 2, 13 +/- 1, and 15 +/- 2. Cumulus-oocyte complexes were graded from A to D on the basis of their morphology, and the better-grade A and B oocytes were used for in vitro maturation and fertilization. A higher proportion of grade A and B oocytes was found for the stimulated vs. unstimulated prepubertal calves at 5 mo of age (92% vs. 49%, p < 0.05) and 7 mo of age (96% vs. 63%, p < 0.05), but the improvement of this parameter by stimulation was not significant for peri- and postpubertal calves at 9 (53% vs. 38%, p > 0.05) and 11 (53% vs. 38%, p > 0.05) mo of age. Embryo development to morula and blastocyst stages was poorer (0-11%, p < 0.05) for oocytes collected from unstimulated calves at 5-9 mo of age than for those from the age-matched but gonadotropin-stimulated groups (10%, 39%, and 31%, at 5, 7, and 9 mo of age, respectively). In calves 11 mo of age, embryo development to morula and blastocyst stages was similar with and without gonadotropin stimulation (48% vs. 40%, p > 0.05) and was comparable to that of adult cow oocytes (45%, p > 0.05). The data suggest that the acquisition of oocyte competence for normal embryo development in prepubertal calves is influenced by animal age and hormonal treatment.

Aging↗
PubMed1997

Effects of apolipoprotein E on dementia and aging in the Shanghai Survey of Dementia.

We investigated the status of the apolipoprotein E allele in 538 participants in the incidence phase of the ongoing Shanghai Survey of Dementia, including 103 demented subjects, 72 with mild cognitive impairment and 363 cognitively normal. The apo E epsilon 4 allele was present in 10.2% of control subjects and the allelic frequency did not change between ages 60 to 96 years. The apo E epsilon 4 allelic frequency was increased both in those wiht Alzheimer's disease (AD) (25.4%) and those with vascular dementia (VaD) (22.2%), but not in those with other dementing illnesses or the cognitively impaired. All of the subjects homozygous for apo E epsilon 4 were demented, three were diagnosed as having AD, and three met NINDS/AIREN criteria for VaD. The increased apo E epsilon 4 allelic frequency in clinically diagnosed VaD patients suggests that some of the infarcts are secondary to congophilic angiopathy. The adjusted odds ratio of developing AD in this community-derived study for persons with at least one apo E epsilon 4 allele was 4.1 (95% CI: 2.2, 7.7). Thus, the apo E epsilon 4 risk of developing AD in this Chinese cohort is similar to that in western community studies.

Age Factors↗
PubMed1997

Pelizaeus-Merzbacher-like disease: exclusion of the proteolipid protein locus and documentation of a new locus on Xq.

A large X-linked kindred with Pelizaeus-Merzbacher like disease (Pelizaeus-Merzbacher disease [PMD] lacking a proteolipid protein [PLP] mutation) was studied for linkage to 34 X-chromosome short tandem repeat polymorphism markers. Recombinational events excluded linkage to PLP and supported linkage to a 9.4-cM critical region more than 10 cM away from PLP on the X chromosome. A maximum 2-point lod score of 3.91 was observed for DXS441 at theta = 0.0. Neuropathologic study of one affected male showed intact myelin. The data thus support a different etiology for a disease that clinically resembles PMD, distinguishable phenotypically only by degree of myelin involvement. Other patients with the clinical diagnosis of PMD but without PLP mutations could have mutations at this new locus.

Adolescent↗
PubMed1997

Cytokine dysregulation and increased oxidation is prevented by dehydroepiandrosterone in mice infected with murine leukemia retrovirus.

The effects of murine leukemia retrovirus infection on production of cytokines was investigated in mice fed different doses of dehydroepiandrosterone (DHEA). Young C57BL/6 female mice were injected with LP-BM5 murine retrovirus or were kept as uninfected controls. Two weeks later, each group was divided into subgroups: fed unsupplemented AIN 93 diet as the control, or diets supplemented with 0.02% DHEA (0.9 mg/mouse/day) or 0.06% DHEA (2.7 mg/mouse/day). The uninfected mice supplemented with 0.06% DHEA showed a significant (P < 0.05) increase in interleukin-2 (IL-2) and gamma-interferon (IFN-gamma) production, and hepatic vitamin E levels. Retroviral infection induced severe oxidative stress that was reduced by DHEAS supplementation in retrovirally infected mice. DHEA supplementation prevented the retrovirus-induced loss of cytokines (IL-2 and IFN-gamma) secretion by mitogen stimulated spleen cells. DHEA also suppressed the production of cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) by T helper 2 (Th2) cells which were otherwise stimulated by retrovirus infection. Thus, immune dysfunction and increased oxidation induced by murine retrovirus infection were largely prevented by DHEA.

Adjuvants, Immunologic↗
PubMed1997

[Kidney lesions complicated by hypoxic ischemic encephalopathy of neonatal pig].

To study the kidney lesions complicated by hypoxic ischemic encephalopathy (HIE) in newborn, we successfully established a neonatal pig model of HIE. Changes in brain tissue similar to those of newborn in HIE were detected after 2 hours of hypoxia and ischemia. Meanwhile, swelling of kidneys, hemorrhage below encapsules, swellin of tubular epithelial cells, necrosing and falling of a few tubular epithelial cells, and narrowing of tubular lumens were observed. The basement membranes of renal tubules remained normal serum BUN and creatinine increased significantly after experiment compared with before (P < 0.025 and P < 0.05 respectively). The results showed that the kidney of neonatal pig was damaged in HIE. But the injury was not severe. After 72 hours free from hypoxia, the structure and function recovered approximately from the injury.

Animals↗
PubMed1997

[Sudden hearing loss in acoustic neuroma].

To avoid misdiagnosis and mistherapy of acoustic neuroma, 104 cases of acoustic neuroma treated between 1986 and 1995 were retrospectively reviewed. Among them, 23 patients (24 ears, 23%) presented with sudden hearing loss as the starting symptoms. The clinical and audiological analysis demonstrated that 54.2% of the ears showed hearing loss over 71 dB HL, and all ears had deteriorated ABRs. -SP/AP was measured in nine ears, seven showed -SP/AP greater than 0.4. Acoustic reflex was negative in all 11 ears tested, and 94.4% of the ears showed abnormal ENG. The rate of positive CT scan was 88.8%. The diagnosis was made with CT pneumo-encephalography or MRI in those with negative CT result. It was concluded that for patients with sudden deafness, ABR should be used as a routine test. When ABR was abnormal, CT scan of the internal auditory meatus was needed.

Adolescent↗
PubMed1997

[Effects of short-term tone exposure on DPOAEs].

Test parameter combinations are known to affect DPOAE measurement. The present study was attempted to find out if different test parameter combinations affect DPOAEs' utility in reflecting the change of cochlear function. Pure tones of moderate intensity (82 dB SPL) and short duration (3 min) were introduced into rabbit's ear canal to cause temporary change of cochlear mechanics, and the change of amplitude of 2f1-f2 DPOAE representing 10 kHz over 10 minutes after the exposure was monitored using equal- and different primary level combinations. It was found that, under the same exposure condition, 2f1-f2 DPOAEs induced by primaries of different levels (L2 = L1 - 12 dB) had showed more initial reduction in amplitude and slower recovery than that induced by primaries of equal levels (L1 = L2). The difference may indicate that there are multiple physiological processes that contribute to the generation of 2f1-f2 DPOAE and that change of DPOAE test parameters may selectively reveal different DPOAE generating processes.

Acoustic Stimulation↗
PubMed1997

[Effects of white noise exposure on nonlinearities of outer hair cell].

The technique of microelectrode has been used to record receptor potentials of outer hair cell (OHC) of seven guinea pigs' cochlea basing on the programmable signal processing system. The nonlinearies of input-output function of the receptor potential recorded from OHC are compared before and after with noise exposure. Results indicated that the input-output functions of the receptor potential of OHC reveal linear behavior increased in linearity in low level and turned to be nonlinear when the sound level increased to 50 dB SPL, and significant saturation was seen in 80 dB SPL. After the white noise exposure (100 dB SPL , 10-20 minutes), the phenomenon of nonlinearity disappeared with the amplitude of receptor potential decreased, which suggested that nonlinearity was easy affected by noise exposure. OHC response recruitment has shown after noise exposure. These results together with preceding clinical observation of loudness recruitment, suggest that loudness recruitment occurs at least in part at the hair cell level.

Animals↗
PubMed1997

[Topographic mapping of slow cortical response in guinea pigs].

Auditory slow cortical responses (SCR) were studied in 10 awake guinea pigs using topographic mapping techniques. Fourteen electrodes were installed through the guinea pig skull and fixed with dental cement. Auditory SCRs were recorded via 13 leads and brain maps were realized on a concerto system. The results showed that SCRs were relatively stable at the temporal lobe, with a stable positivity (31.25-37.50 ms TP) followed by a negativity (62.50-72.50 ms TN). Variability was seen at other leads. The foci of maximum positivity and negativity were seen at the temporal cortex. The results suggest that there are multiple contributions to SCRs which partially overlap in time, and that auditory cortex contribute significantly more than other sources. SCRs also received auditory information in parallel from the brainstem. The focus of AM-evoked SCRs was seen located at temporal lobe while that of FM-evoked SCRs at temporal and frontal lobes. It suggests that intensity analysis is essentially completed at the temporal cortex whereas precise frequency discrimination relies on function of higher integrating centers.

Animals↗
PubMed1997

[Effect of loss of consciousness induced by repeated lower body negative pressure on blood-brain barrier permeability in rats].

To investigate the effect of loss of consciousness induced by repeated +Gz on the brain and its mechanism, changes of blood-brain barrier (BBB) permeability and brain water content after repeated lower body negative pressure (LBNP) induced loss of consciousness were observed in 30 rats. Rats were anesthetized and exposed to LBNP (-4.0 kPa). The pressure rapidly returned to control level 2 min after EEG became isoelectric. The BBB permeability was measured using lanthanum trace labeling with electron microscopy and brain water content was determined after one or three LBNP exposures. Most tight junctions among endothelial cells opened through which the lanthanum entered into the neurons and extra cellular space and water content in brain tissues increased significantly (P < 0.05) 1 h after 3 LBNP exposures. It demonstrated that 3 exposures to LBNP induced loss of consciousness can result in an increase of BBB permeability in rats, which may play an important role in the development of G-induced brain edema.

Aerospace Medicine↗
PubMed1997

[Generation of human monoclonal antibodies against hemorrhagic fever with renal sydrome (HFRS) virus].

Peripheral blood lymphocytes (PBL) were obtained from healthy donors and treated with L-leucy-leucin methy (LeuLeu-OMe). The LeuLeu-OMe treated PBL were in vitro immunized with HFRS virus proteins (55kD, 67kD) for 6 days, and then fused with K6H6/B5 cells in medium containing 45% (PEG) and 7.5% DMSO. The fused cells were seeded in 96-well plates at cell density 0.5-1 x 10(5) cells/well in HAT supplemented RPMI-1640 medium. After 14-20 days, 3 positive wells were deteced by ELISA and two (1B7, 2D5) of the 3 hybridoma were stable after 4 time cloning. The hybridoma 2D5 appears to be with high ability of production of the antibodies at a concentration of 20-30 microg/ml/10(6) cells/24h. It was proved by IFAT that 2D5 McAb was specific for HFRSV.

Antibodies, Monoclonal↗
PubMed1997

[The combinations of separation modes in multidimensional high performance liquid chromatography (MDHPLC)].

MDHPLC is a new chromatographic technique, in which fractions from a separation system are selectively transferred to one or more secondary chromatographic systems with different separation mechanism to enhance resolution and sensitivity, or to decrease analysis times. In this review, the principle, characteristics and developments of MDHPLC are discussed. The various possible combinations of separation modes in HPLC [such as, size exclusion chromatography/reversed-phase chromatography (SEC/RPC), ion exchange chromatography/reversed-phase chromatography (IEC/RPC), normal bonded phase chromatography/reversed-phase chromatography (NPC/RPC), size exclusion chromatography/ion exchange chromatography (SEC/IEC), liquid-solid chromatography/reversed-phase chromatography (LSC/RPC), affinity chromatography/reversed-phase chromatography (AC/RPC) and achiral column/chiral column] and their applications are systematically reviewed with 63 references.

English Abstract↗