Biomedical subjects

Lin Lu

Publications and source records attributed to Lin Lu.

63 records · Page 4Linked to original sources

PubMed2002

Reactivation of cocaine conditioned place preference induced by stress is reversed by cholecystokinin-B receptors antagonist in rats.

The effects of different cholecystokinin (CCK) receptor antagonists (devazepide and L365,260) on cocaine or stress-induced reactivation of cocaine conditioned place preference (CPP) were investigated in rats. After receiving alternate injection of cocaine (10 mg/kg) and saline for 8 consecutive days, the rats spent more time in the drug-paired side (cocaine CPP) on day 9. These animals did not show cocaine CPP on day 31 following saline-paired training daily from days 10 to 30 (21-day extinction). However, a single injection of cocaine (10 mg/kg) or 15 min of intermittent footshock could reinstate CPP on day 32 with significant more time spent in the drug-paired side in comparison with that on day 0. Systemic injection of CCK-A receptor antagonists, devazepide (0.1 and 1 mg/kg, i.p.), 30 min before cocaine priming, significantly attenuated cocaine-induced reinstatement of CPP, while CCK-B receptor antagonist, L365,260 (0.1 and 1 mg/kg, i.p.), did not show a similar effect. In contrast, pretreatment with L365,260 (0.1 and 1 mg/kg, i.p.) but not devazepide (0.1 and 1 mg/kg, i.p.) significantly blocked stress-induced reinstatement of CPP. In another experiment, CCK-A or B receptor antagonists were infused into nucleus accumbens or amygdala to determine which brain area are involved in the role of different CCK receptors in stress or drug-induced relapse to cocaine seeking. The results show that infusion of the devazepide (10 microg) into the nucleus accumbens significantly inhibited the cocaine-induced reinstatement of CPP, while infusion of devazepide (1 and 10 microg) into amygdala did not affect cocaine-induced reactivation of CPP. Interestingly, infusion of L365,260 (1 and 10 microg) into both nucleus accumbens or amygdala significantly attenuated or blocked stress-induced reinstatement of CPP. These findings demonstrate that CCK-A and B receptor have different roles in relapse to drug craving and further suggest that the brain areas involved in the CCK receptors on reinstatement of drug seeking are not identical. CCK-B receptor antagonists might be of some value in the treatment and prevention of relapse to stress-induced to drug craving following long-term detoxification.

Animals↗

PubMed2002

The reinstatement model of drug relapse: history, methodology and major findings.

RATIONAL AND OBJECTIVES: The reinstatement model is currently used in many laboratories to investigate mechanisms underlying relapse to drug seeking. Here, we review briefly the history of the model and describe the different procedures that have been used to study the phenomenon of reinstatement of drug seeking. The results from studies using pharmacological and neuroanatomical techniques to determine the neuronal events that mediate reinstatement of heroin, cocaine and alcohol seeking by acute priming injections of drugs, drug-associated cues and environmental stressors are summarized. In addition, several issues are discussed, including (1) the concordance between the neuronal mechanisms involved in drug-induced reinstatement and those involved in drug reward and discrimination, (2) the role of drug withdrawal states and periods in reinstatement of drug seeking, (3) the role of neuronal adaptations induced by exposure to drugs in relapse, and (4) the degree to which the rat reinstatement model provides a suitable preclinical model of relapse to drug taking. CONCLUSIONS: The data derived from studies using the reinstatement model suggest that the neuronal events that mediate drug-, cue- and stress-induced reinstatement of drug seeking are not identical, that the mechanisms underlying drug-induced reinstatement are to some degree different from those mediating drug discrimination or reward, and that the duration of the withdrawal period following cocaine and heroin self-administration has a profound effect on reinstatement induced by drug cues and stress. Finally, there appears to be a good correspondence between the events that induce reinstatement in laboratory animals and those that provoke relapse in humans.

Animals↗

PubMed2002

Vitreous surgery in highly myopic retinal detachment resulting from a macular hole.

PURPOSE: This study aimed to assess the therapeutic effect of vitreous surgery in conjunction with photocoagulation for highly myopic retinal detachment resulting from a macular hole. METHODS: Sixty-two consecutive highly myopic patients (65 eyes) with retinal detachment from macular holes underwent vitreous surgery. Gas tamponade in conjunction with laser photocoagulation was performed in 46 eyes (44 cases, group 1); gas tamponade only was performed in 12 eyes (11 cases, group 2); and silicone oil tamponade only was performed in seven eyes (seven cases, group 3). Additional laser photocoagulation was given in group 1 if necessary. The anatomical and functional success rates were compared between the groups. RESULTS: Primary retinal reattachment was achieved in 43 eyes (93.5%) in group 1, seven eyes (58.3%) in group 2 and four eyes (57.1%) in group 3. Final visual acuity was 6/60 or more in 24 eyes (52.2%) in group 1, in six eyes (50.0%) in group 2 and in three eyes (42.9%) in group 3. The initial retinal reattachment rate was significantly higher in group 1 than in group 2 (P = 0.0075) and group 3 (P = 0.0248). The macular hole was completely closed in 18 eyes in group 1 and one eye in group 2 after 2 months or longer. A thin fibrous membrane and scar could be easily noticed beneath the macula in 15 eyes. CONCLUSION: Vitreous surgery in conjunction with laser photo-coagulation can improve the surgical success rate for highly myopic retinal detachment resulting from a macular hole.

Female↗

PubMed2002

Use of MIB-1 in the assessment of esophageal biopsy specimens from patients with gastroesophageal reflux disease in well- and poorly oriented areas.

MIB-1, a proliferation marker may be useful in the assessment of esophageal biopsy specimens for gastroesophageal reflux disease (GERD). Forty-five hematoxylin and eosin-stained esophageal biopsy specimens were histologically assessed for basal zone height, papillary length, and inflammatory cell infiltrate and classified as 10 normal and 35 esophagitis. The percentage of MIB-1-positive area (MIB-1% area) was measured on immunostained sections using image analysis (CAS 200) in the basal half of well-oriented areas and adjacent to five cross-sectioned papillae (c-pap) in poorly oriented areas. The cell layer of the MIB-1-positive cell furthest from the basal layer of the c-pap was also noted. MIB-1% area was significantly greater in both well- and poorly oriented areas of esophagitis biopsy specimens compared with normal biopsy specimens. MIB-1 positivity in the basal half and c-pap were correlated (r = 0.43, p = 0.017). MIB-1 expression correlated with basal zone height and eosinophil infiltrate (r = 0.61, p < 0.001; r = 0.32, p = 0.03, respectively). The cell layer with positive cells furthest from c-pap in normal and esophagitis biopsy specimens was two and six layers, respectively. Using 31% as a threshold to detect abnormal findings, the MIB-1 sensitivity/specificity and positive predictive value in the basal half and c-pap were 86, 70, 91% and 80, 80, 94%, respectively. In summary, MIB-1 staining correlates with basal zone hyperplasia and eosinophil infiltrate seen in GERD. MIB-1 staining can be assessed both in well- and poorly oriented areas as MIB-1% areas. Alternatively simply finding MIB-1 positive cells more than three cell layers from the basal layer is abnormal and consistent with GERD.

Biopsy↗

PubMed2002

Impact of diabetes-associated lipoproteins on generation of fibrinolytic regulators from vascular endothelial cells.

Increased thrombotic tendency and decreased fibrinolytic activity have been frequently found in patients with diabetes mellitus (DM). Previous studies by our group indicated that nonenzymatically glycated low density lipoprotein (LDL) increased plasminogen activator inhibitor-1 (PAI-1) production and decreased the generation of tissue plasminogen activator (tPA) from cultured human umbilical vein endothelial cells (HUVEC). The present study demonstrates that plasma levels of PAI-1 or PAI-1/tPA were significantly increased in patients with type 1 (n = 10) and type 2 DM (n = 14) compared with those in healthy controls (n = 10; P < 0.05 or 0.01). LDL from patients with type 1 or type 2 DM, and very low density lipoprotein (VLDL) from patients with type 2 DM induced significantly greater increases in the release of PAI-1 and more profound reduction in tPA generation from HUVEC compared with corresponding lipoproteins from healthy controls (P < 0.05 or 0.01). HDL from diabetic patients did not significantly alter the generation of PAI-1 or tPA from endothelial cells (EC) compared with HDL from controls. Comparable effects of lipoproteins from DM patients on the generation of PAI-1 and tPA were found in human coronary artery EC. LDL and VLDL from patients with type 2 DM enhanced the activation of PAI-1 promoter (-1528/+55)/luciferase reporter gene transiently transfected in HUVEC (P < 0.01). The results of the present study suggest that LDL and VLDL from patients with DM reduce the generation of tPA and increase PAI-1 production through the activation of the PAI-1 promoter in vascular EC.

Adult↗

PubMed2002

[Therapeutic vitrectomy for severe uveitis and its complications].

OBJECTIVE: To investigate the therapeutic value of vitrectomy for uveitis and its complications. METHODS: Vitrectomy was performed on 14 patients (14 eyes) with uveitis. In these 14 eyes, there were 6 eyes with severe opacity of vitreous, 5 eyes with cataract, 5 eyes with retinal detachment, and 3 eyes with poor response to medication. Pars plana lenectomy, scleral cryopexy, buckling procedure, endolaser photocoagulation, gas-fluid exchange or silicone oil intraocular tamponade were added according to the different needs. The follow-up varied from 18 to 45 months. RESULTS: Twelve of the 14 eyes obtained better visual acuity, and in the other two light perception remained; less drugs were used after operation in all cases, and the uveitis was controlled. CONCLUSION: Vitrectomy is an effective method for severe uveitis and its complications both in the improvement or stabilization of visual acuity and in the reduction or cessation of systemic treatment.

Adolescent↗

PubMed2002

[An experimental study on effect of perfluorohexyloctane on corneal endothelial cells].

OBJECTIVE: To investigate the effect of perfluorohexyloctane on corneal endothelial cells in rabbit eyes. METHODS: Fifteen New Zealand albino rabbits were divided into two groups: experiment group (F(6)H(8)) and control group (BSS). All rabbits underwent anterior chamber injection of 0.15 ml F(6)H(8) or BSS. Slit-lamp biomicroscopy and corneal endothelium photography were performed pre- and post-injection. Histopathological examination and transmission electron microscopy (TEM) were performed after the rabbits were sacrificed. RESULTS: All the corneas were clear. Since 4 weeks postoperatively, the endothelial cells were markedly irregular in size and shape, and the number of endothelial cells was markedly decreased. Multilayered retrocorneal membranes grew gradually from 4 weeks after surgery. Vacuolar degeneration was seen in some endothelial cells. Nuclear degeneration and edema of endoplasmic reticulum were seen in TEM. CONCLUSION: Corneal endothelial cells degenerated after contacting with F(6)H(8) for 4 weeks. As a silicone solvent, F(6)H(8) should be removed out completely after injection. It is not recommended to apply this agent as a new intraocular temponade.

Animals↗

PubMed2002

Experimental study of effect of perfluorohexyloctane to retina.

OBJECTIVE: To investigate the effect of perfluorohexyloctane to the retina of rabbit eyes. METHODS: Perfluorohexyloctane (experimental group) or BSS(control group) into vitreous cavities of fifteen vitrectomized New Zealand white rabbits. A slit-lamp biomicroscope and an indirect ophthalmoscope were used to examine all the eyes pre- and postoperation. Histopathological examination was performed after the rabbits were sacrificed. RESULTS: Perfluorohexyloctane was injected into the vitreous cavity forming a single large layerclear globe. No retinal detachment and cataract were found. The edema of outer plexiform was significant, and then get a darker cytoplasm and nucleoplasm. CONCLUSIONS: Perfluorohexyloctane in vitreous cavity had significant side effects on retina. As a silicone solvent, it should be removed out completely after injection. We don't recommend to use it as a new intraocular tamponade.

Animals↗

PubMed2001

Reactivation of morphine conditioned place preference by drug priming: role of environmental cues and sensitization.

RATIONALE: Relapse is a major characteristic of drug addiction and remains the primary problem in treating drug abuse. Despite a great deal of research, the exact factors that determine renewed drug-seeking and persistent craving for them remain unclear. OBJECTIVE: The present study was designed to evaluate the role of environmental cues and behavioral sensitization in reactivation of place preference following long-term extinction of morphine conditioned place preference (CPP) in rats. METHODS: After being injected with morphine and saline alternately for 6 days to induce morphine CPP, the rats were subjected to extinction of conditioning for 21 days. The rats were then administered various doses of morphine, heroin, or cocaine and confined in the previous drug- or saline-paired compartment. CPP was determined. Some rats were treated with scopolamine or naloxone prior to administration of these three drugs. RESULTS: Morphine CPP disappeared following a 21-day extinction. A single injection of morphine, heroin, or cocaine evoked place preference for the previous drug-paired side. However, place preference for the previous vehicle-paired side was induced after the animals received a single injection of morphine, heroin or cocaine and confined to the previous vehicle-paired compartment. Administration of naloxone prior to drug treatment significantly attenuated the place preference induced by morphine or heroin, but had no significant effect on the place preference elicited by cocaine. Administration of the cholinergic antagonist scopolamine before morphine, heroin and cocaine inhibited the expression of place preference. CONCLUSIONS: Environment-related cues and behavioral sensitization play critical roles in the incentive motivation underlying drug-seeking behaviors.

Animals↗