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Biomedical subjects

L Li

Publications and source records attributed to L Li.

At least 1,279 records · Page 71Linked to original sources
PubMed1997

Effects of short- and long-term withdrawal from gestational cocaine treatment on maternal behavior and aggression in Sprague-Dawley rats.

Pregnant rats were treated with 30 mg/kg per day cocaine or normal saline either throughout gestation (GD 1-20, cocaine and saline withdrawal) or throughout the gestation and continuing into lactation for 10 days postpartum (cocaine and saline nonwithdrawal). All cocaine-treated dams exhibited more disruptions in the onset of maternal behavior (retrieval, licking, crouching) and were more aggressive (threats and attacks) towards an intruder on postpartum day 6 than saline-treated dams. There were no significant differences in these behaviors between withdrawn and nonwithdrawn cocaine-treated dams. These findings indicate that changes in maternal behavior following chronic moderate cocaine treatment are not simply the result of withdrawal from cocaine treatment following gestation and that other possible mechanisms should be examined.

Aggression↗
PubMed1997

Expression of five selected human mismatch repair genes simultaneously detected in normal and cancer cell lines by a nonradioactive multiplex reverse transcription-polymerase chain reaction.

Abnormalities in at least 1 of 5 mismatch repair (MMR) genes (hMSH2, hMLH1, hPMS1, hPMS2 and GTBP/hMSH6) are found in hereditary nonpolyposis colon cancer and sporadic colon cancers. We used a single-reaction multiplex reverse transcription (RT)-polymerase chain reaction (PCR), with the beta-actin gene as an internal control, to simultaneously evaluate expression of these 5 known human MMR genes in normal and tumor cell lines with known or uncharacterized mutations in MMR genes. The relative quantitation of the transcripts is demonstrated by controlling the number of PCR cycles and titrating cDNA with a dose-curve. The 13 normal cell lines tested were derived from normal lymphocytes, skin, thymus, breast, lung, colon, liver and kidney. The 26 cancer cell lines were derived from melanoma and cancers of the brain, breast, lung, colon, pancreas and prostate. All 5 MMR genes were ubiquitously expressed in all normal cell lines tested, suggesting their housekeeping roles. Aberrant MMR gene expression was only observed in the colon cancer cell lines. Two previously uncharacterized colon cancer cell lines did not express hMLH1. These data suggest that this nonradioactive multiplex RT-PCR assay for MMR gene expression may be useful for fast screening for genetic alterations that may affect gene expression and so may aid molecular analysis of MMR-related colon cancer.

Adaptor Proteins, Signal Transducing↗
PubMed1997

[Astrogliosis and basic fibroblast growth factor].

OBJECTIVE: To study the relationship between reactive astrogliosis and its autocrine bFGF. METHODS: On the primary astrocyte culture with mechanical scratch, the dynamic expression of bFGF, PCNA, GFAP and GFAP-mRNA were determined by immunocytochemistry and in situ hybridization. RESULT: Astrocytes at the edge of the injury began to express bFGF 2 hours after scratching and reached its peak by the 12th hour, then declined after 2 days. GFAP-mRNA was detectable in astrocytes near the injury from the 6th hour and reached its peak within 24 hours. A few hypertrophic astrocytes in the injured area expressed GFAP-mRNA on the 3rd day. Enhanced GFAP expression of astrocytes was observed with hypertrophy of cytoplasma which extended wide processes into the injured area from the day of the scratch and reached its peak on the 2nd day. On the 3rd day, the previously injured area was covered with hypertrophic astrocytes. PCNA was expressed 2 hours after damage by some of the astrocytes in the vicinity of injury. CONCLUSION: Autocrine bFGF was the early response of reactive astrocytes and bFGF may act as promoter of reactive astrogliosis. Enhanced GFAP expression was the result of upregulation of GFAP-mRNA. The prominent event of reactive astrogliosis was the hypertrophy of astrocytes.

Animals↗
PubMed1997

[Effect of catecholaminergic agonists and antagonists on adaptive gastric mucosal protection in rats].

The gastric mucosal damage caused by 70% ethanol significantly decreased in rats pretreated with chronic mild restraint stress (CMRS, P < 0.001). This adaptive mucosal protection induced by CMRS was absent in sympathectomized rats, while the administration of isoprenaline or dopamine could partially, and norepinephrine could not, restore the protection. In rats with rntact sympathetic nerve, preinjection of haloperidol or propranolol inhibited CMRS-induced protection which, however, was not affected by phentolamine. No change in plasma somatostatin level was observed either in stress or sympathectomized rats alone or in stress plus sympathectomized rats. The results suggest that the sympathetic nerve or its mimetic agent ang this is are involved in the adaptive protection of the gastric mucosa possibly mediated through beta and dopamine receptors.

Adaptation, Physiological↗
PubMed1997

[Effect of vagi excitation on HRV and the exploration of its mechanism].

The experiments were performed on rabbits anaesthetized with urethane and chloralose. The ECG heart rate and blood pressure were recorded. The power spectrum analysis of R-R interval (RRI) was done by computer. Electrical stimulation of nucleus ambiguus (NA), depressor nerve (DN) and the peripheral end of right vagus (RV) all evoked a decrease in heart rate and blood pressure (P < 0.001), and an increase in LF, HF, LF/HF, TV and VLF (P < 0.05-0.001); The LF, HF, LF/HF, TV and VLF were significantly decreased (P < 0.05-0.01) by pretreatment with intravenous injection of atropine. The enhancement of LF during stimulating DN and NA were attenuated (P < 0.05) by prior intravenous injection of propranolol. It is suggested that vagus activity is one of the major regulator of HRV and mediates VLF. The HF is mediated only by vagi, while the LF is mediated by both vagi and sympathetic system.

Animals↗
PubMed1997

[Extraction of P3 wave from ERP by using the wavelet transform].

A new time-frequency filter based on correlation of wavelet transform coefficient between mean ERP and single ERP is presented in this paper. This filter can extract the P3 wave from the background of eye-moving and spontaneous EEG activity.

Acoustic Stimulation↗
PubMed1997

[Role of substance P in pressor response of lateral hypothamus-perifornical region to glutamate].

Substance P(SP)-immunoreactive cell bodies, axon terminals and SP receptors were widely scattered in most pressor areas. Lateral hypothalamus (LH) contains SPergic neurons; and SPergic fibers-SP receptors are present in LH projection areas; hence the role of SP in LH-pressor response was studied. The results showed that: (1) microinjection of glutamate into the lateral hypothalamus-perifornical region (LH/PF) or SP into LH projection areas: the locus coeruleus (LC), periaqueductal gray matter (PAG) or nucleus parabrachialis (NPB), respectively, all could induce pressor response; (2) preinjection of DPDPDT (a substance P antagonist) into the LC, PAG (but not NPB) reduced the LH/PF pressor response; (3) intra-RVL (rostral ventrolateral medulla) injection of phentolamine, propranolol or atropine also markedly attenuated the LH/PF pressor response. Taken together with our previous findings that alpha-, beta- and M-receptors in the RVL mediated the pressor response to excitation of LC, and alpha-, beta-receptors mediated the PAG-pressor response, it is suggested that the LH/PF pressor response may be brought about via the activation of LC- and PAG-RVL systems by SPergic fibers from the LH/PF.

Animals↗
PubMed1997

[Detection on morphine concentration changes of postmortem cardiac blood in rats by HPLC].

This study used HPLC to detect the concentration of morphine in cardiac blood of rats treated with intramuscular injection of therapeutic and toxic dose morphine. The results showed, in the group with therapeutic dose morphine, the cardiac blood concentration of morphine increased significantly within 96 h after death (P < 0.01), these increase of the cardiac blood morphine correlated well with time. In the group with toxic dose morphine, the cardiac blood concentration of morphine did not change obviously within 12 h after death, but increased gradually 24 h, 48 h, 96 h after death (P < 0.01), however, the morphine changes intensity is not more significant than the therapeutic dose. This study proved that the dose of morphine injected antemortem affects directly the postmortem cardiac blood morphine levels. It is analysed for the possible mechanism of the change.

Animals↗
PubMed1997

[Distribution of fibronectin in kidney of IgA nephropathy and its clinicopathological correlation].

To understand of fibronectin (Fn) distribution in kidney of IgA nephropathy (IgAN) and their meaning, we studied 107 cases of IgAN. Strong positive staining of Fn was shown in mesangial areas with proliferation, crescents, segmental sclerosis, and sclerosing glomeruli. 33 patients (group M) had Fn distributed only in mesangium, and 74 (group B) had Fn along the capillary walls as well as mesangium. Compared with those in group M, patients in group B showed more severe renal histological lesions (P < 0.01), crescent formation and stronger staining of IgG, C3 (P < 0.05) and IgA (P < 0.01) along the capillary walls. More severe changes of GBM were found in group B under electron microscopy. Clinically, 24th protein excretion (P < 0.01), incidences of hypertension and nonselective proteinuria were significantly higher (0.01 < P < 0.05), and Ccr was lower (0.01 < P < 0.05) in group B. 44 patients were followed up for 19.2 months, and the incidence of renal function deterioration in group B increased much more (0.01 < P < 0.05) than that in group M. Our results dmonstrated that the increase of Fn along the golmerular capillary walls might reflect that excessive proliferation of mesangial matrix, severe immune injury in capillary wall and damage of GBM, which are correlated with unfavorable clinical features and progression of the disease.

Adult↗
PubMed1997

[The effect of cationic ferritin to the permeability of renal glomerular basement membrane and the mesangial area].

OBJECTIVE: To study the effect of cationic ferritin (CF) to the permeability of the glomerular basement membrane (GBM) and the mesangial area. METHODS: Single dose of CF 50mg/kg/rat given intravenously. Samples taken from the kidney were studied under electronic microscope by polyethylenimine (PEI) staining. RESULTS: The number of PEI granules in GBM changed obviously while those in the mesangial matrix (MM) remained unchanged. CONCLUSION: The negative charge in GBM serves as a charge barrier relating with proteinuria and the MM serves as the lymphatic pathway with no connection with proteinuria.

Animals↗
PubMed1997

[Primary clinical experience of neuroendoscopy: report of 19 cases].

10 cases of basal ganglion and 6 of subcortical hematoma were evacuated. One case of temporal and 2 cases of para- and intra-ventricle arachnoid cyst were fenestrated towards the cistern or lateral ventricle. Burred holes were near the lesion, through which endoscope should run. We guided the endoscope to the target by stereotatic equipment in 10 cases of basal ganglion hematoma and 1 case of ventricle arachnoid cyst, and introduced endoscope by free-hand in other cases. Hematoma group: CT reexamination within 48 hours showed that the residual hematoma was less than 20%-30% in 9 of 11 cases. Cyst group: symptoms of all cases of arachnoid cysts were alleviated after intervention. CT after a month showed that fenestration entrance could be seen clearly in 2 cases. The cyst reduced 20%-30% in 1 case. There were no direct complications in the group. It was shown that operation by endoscope is minimal invasive and little complicated.

Adolescent↗
PubMed1997

[The experimental pathology and clinical treatment of microwave tissue coagulation for ocular superficial lesions].

OBJECTIVE: To investigate the therapeutic effect of a new therapy, microwave tissue coagulation (MTC), for treatment of ocular diseases. METHODS: HSE-5M Mircotaze (manufactured by HEIWA Electronic Industrial Co. Osaka, Japan) was used for the treatment of sixty-four cases with ocular superficial lesions. Animal experiment was performed with this technique before application in patients. Twelve rabbit monocular eyeballs were coagulated just posterior to the corneoscleral limbus in order to find a dose which is effective and safe for the human eye ball. The models of microwave coagulative lesions were made in the contralateral eyes of the twelve rabbit eyeballs. RESULTS: The coagulation-induced "ulcers" were exfoliated gradually and healed finally from three to seven days. Histopathology of the coagulative areas showed coagulative necrosis with infiltration of lymphocytes and plasma cells. The results of sixty-four cases treated with MTC technique show that the damaging effect of coagulation on tissues is very mild, so that it heals very soon and the clinical process is consistent with the experimental pathological process. CONCLUSIONS: If the dosage of the technique is controlled in the range of safety and effectiveness, the MTC therapy is effective for the treatment of superficial ocular disease. The clinical and pathological examinations demonstrate that the therapy does not damage the ocular structure.

Animals↗
PubMed1997

[Changes in contents of Zn, Cu, Fe, Ca, Mg in serum, urine and blister fluid after burn injury].

106 burned patients were divided into two groups: group L consisted of 57 patients with burns larger than 30% TBSA, and group S consisted of 49 patients with burns smaller than 30% TBSA. The contents of Zn, Cu, Fe, Ca, Mg in serum, urine and blister fluid were determined on 1, 2, 3, 7, 14, 21, 28 days after burn injury. The results indicated that all of the elements in serum were decreased except serum Fe on first day, and the levels were much lower in group L than in group S. The contents of Zn, Cu, Fe in urine were increased significantly and Ca, Mg in urine decreased. The contents of Zn, Fe, Ca in blister fluid were similar to normal values of serum, and Cu, Mg in blister fluid were less than that of serum. The studies indicated that the decrease in contents of Zn, Cu, Fe, Ca, Mg after burn injury was propably related to loss of these elements from urine and wound.

Adolescent↗
PubMed1997

[beta-Endorphin enhances IL-2 and IFN-gamma gene expression in human blood mononuclear cells].

The effect of beta-endorphin (beta-END) stimulation of cytokines production by PHA-induced human peripheral blood mononuclear cells (PBMC) was studied by reverse transcription in combination with polymerase chain reaction (RT/PCR), slot blotting and hybridization to detect and measure messenger RNA (mRNA). beta-END significantly and dose dependently enhanced IFN-gamma and IL-2 mRNA expression of T cells and naloxone (Nal) reversed the effect of beta-END on IL-2 mRNA expression. The results further demonstrate the important link between the neural system and the immune system.

Dose-Response Relationship, Drug↗
PubMed1997

[IL-2, IFN-gamma, and TNF-alpha mRNA expression in peripheral blood mononuclear cells in patients with multiple sclerosis].

We determined the cytokine messenger RNA (mRNA) expression patterns of peripheral blood mononuclear cells from 17 patients with multiple sclerosis (MS) and 11 normal controls, by using a quantitative reverse transcription in combination with polymerase reaction (RT/PCR) and Southern blot hybridization method. A significantly higher levels of IL-2, IFN-gamma mRNA in patient with MS compared to normal controls and significantly higher level of expressions of IFN-gamma, TNF-alpha mRNA were detected in active MS patients compared to those with stable desease (P < 0.05). These data further support the central role of some cytokines in the pathophysiology of this autoimmune disease.

Adult↗