Long-term effects of a high-dose methamphetamine regimen on subsequent methamphetamine-induced dopamine release in vivo

Rats were treated with a high-dose methamphetamine (METH) regimen (40 mg/kg/injection, four times at 2-h intervals) or a saline regimen (four injections at 2-h intervals). Temperature related measures taken during the high-dose METH treatment were maximum core temperature and minimum chamber temperature. Fourteen rats (METH N=7; Saline N=7) were implanted with in-vivo dialysis probes 4-7 weeks post-regimen (average=6 weeks). The next day, they received a challenge dose of METH (4.0 mg/kg) and dopamine release was measured. Results showed a significant decrease in challenge-induced dopamine release in rats previously treated with the high-dose METH regimen. These findings demonstrate a functional deficit in the dopamine system 6 weeks after high-dose METH treatment. Temperature-related measures taken during the high-dose regimen were not correlated with METH-induced dopamine release 6 weeks later. An additional group of rats were sacrificed 6 weeks after the high-dose regimen (METH N=12; Saline N=10), and their brains was analyzed for dopamine and serotonin concentrations. Tissue concentrations of dopamine were significantly depleted in striatum and nucleus accumbens/olfactory tubercle, but not septum, hypothalamus, or ventral mid-brain 6 weeks after the high-dose regimen. Tissue concentrations of serotonin were also significantly depleted in striatum, nucleus accumbens/olfactory tubercle, hippocampus, somatosensory cortex, but not septum, hypothalamus or ventral mid-brain. Significant correlations between the temperature-related measures and post-mortem neurotransmitter tissue concentrations were region and transmitter dependent.     

Spreading epileptiform discharges and cortical regional blood flow in rabbits.

Electric activities from brain slices of guinea pig olfactory cortex were studied during gradual cooling without a temperature gradient. At normal temperature the potential evoked by stimulation of the lateral olfactory tract consists of an initial spike (IS), a negative (N), and a positive (P) potentials. The IS potential has been considered to be presynaptic in origin and the latter two postsynaptic. During cooling from 37 to 15 degrees C, the amplitude of both the IS and the N potentials increased to attain the maximum value (10-36% increase) at about 32 degrees C, then decreased gradually and disappeared at around 15 degrees C. On the other hand, the durations of the IS and the N potentials were prolonged gradually on cooling from 37 to 17 degrees C. Most of the olfactory cortical neurons responded with one or two firings to the tract stimulation. The firing numbers increased on cooling down to about 32 degrees C and declined on further cooling, which corresponds with the behavior of the N potential. All these effects were reversible on rewarming. Augmentation of the N potential might depend primarily on the increase in amplitude of the IS potential and secondarily on the increase of amount of liberated transmitter substance and/or the delayed inactivation process of the transmitter action.     

Increased olfactory sensitivity in euthymic patients with bipolar disorder with event-related episodes compared with patients with bipolar disorder without such episodes

OBJECTIVE: Some patients with bipolar disorder experience mood episodes following emotional life events, whereas others do not. There is evidence that orbitofrontal hypoactivity may be related to this, because the orbitofrontal cortex is involved in the regulation of emotional and behavioural responses to external events. The close anatomical and functional connection between the orbitofrontal cortex and olfactory processing suggests that patients with bipolar disorder and heightened emotional reactivity may exhibit altered olfactory function compared with patients with bipolar disorder who do not exhibit this sensitivity. METHODS: In this pilot study, olfactory function was assessed in patients with bipolar disorder and a history of event-triggered episodes (n = 7) and in patients with bipolar disorder without such a history (n = 9) at the Department of Psychiatry and the Taste and Smell Clinic of the University of Dresden, Germany. Each patient's bipolar disorder was in remission at study entry, and they were on monotherapy with mood stabilizers. Assessment included olfactory event-related potentials (ERP) and psychophysical tests for odour threshold, odour identification and olfactory quality discrimination. RESULTS: Odour thresholds were lower in patients with bipolar disorder and event-triggered episodes compared with the other patient group. In addition, patients with event-triggered episodes exhibited shorter N1 peak latencies of the olfactory ERP. CONCLUSIONS: Our findings indicate disinhibition of orbitofrontal areas involved in the processing of emotional events in a subset of patients with bipolar illness.     

Combining bupropion SR with venlafaxine, paroxetine, or fluoxetine: a preliminary report on pharmacokinetic, therapeutic, and sexual dysfunction effects

BACKGROUND: This study was designed to evaluate the effect of combining bupropion sustained release (SR) with venlafaxine, paroxetine, or fluoxetine in patients who reported unacceptable sexual dysfunction when treated with monotherapy with the latter 3 agents. METHOD: Following a minimum of 6 weeks of antidepressant treatment with a selective serotonin reuptake inhibitor (SSRI) or venlafaxine (a serotonin-norepinephrine reuptake inhibitor), eligible subjects received a further 8 weeks of monitored combination therapy with bupropion SR at a dose of 150 mg/day with no alterations to index antidepressant dosing. RESULTS: There was a clinically significant benefit in 14 (78%) of 18 partial responders or nonresponders, and 33% (N = 6) achieved a full response (chi2= 8.06, df = 2, p = .017). Sexual dysfunction, particularly a decrease in orgasmic delay, was also significantly improved with combination therapy (men: paired t = -2.1, df = 6, p = .08; women: paired t = -3.0, df = 7, p = .02). Plasma monitoring of drugs and their metabolites revealed a statistically significant increase in venlafaxine levels (F = 6.89, df = 4,24; p = .001) accompanied by a decrease in O-desmethylvenlafaxine (F = 14.26; df = 4,24; p < .0005) during combined treatment with bupropion SR. There were no statistically significant changes in plasma levels of SSRIs (paroxetine and fluoxetine) during the trial. CONCLUSION: Bupropion had an effect on the pharmacokinetics of venlafaxine but not those of the SSRIs. Further investigation of combination treatments under randomized, double-blind conditions is recommended.     

Olanzapine/fluoxetine combination for treatment-resistant depression: a controlled study of SSRI and nortriptyline resistance

BACKGROUND: This 8-week, double-blind, multicenter study was undertaken to replicate, in a larger sample of patients with treatment-resistant major depressive disorder (MDD; DSM-IV criteria), the results of a pilot study of the olanzapine/fluoxetine combination. METHOD: The study was begun in August 1999. The primary entry criterion was a history of failure to respond to a selective serotonin reuptake inhibitor (SSRI). Patients (N = 500) who subsequently failed to respond to nortriptyline during an open-label lead-in phase were randomly assigned to 1 of 4 treatment groups: olanzapine (6-12 mg/day) plus fluoxetine (25-50 mg/day) combination, olanzapine (6-12 mg/day), fluoxetine (25-50 mg/day), or nortriptyline (25-175 mg/day). The primary outcome measure was baseline-to-endpoint mean change in score on the Montgomery-Asberg Depression Rating Scale (MADRS). RESULTS: At the 8-week study endpoint, MADRS total scores decreased by a mean 8.7 points from baseline (28.5) with the olanzapine/fluoxetine combination, 7.0 points from baseline (28.4) with olanzapine (p = .08), 8.5 points from baseline (28.4) with fluoxetine (p = .84), and 7.5 points from baseline (28.8) with nortriptyline (p = .30), with no significant differences among the therapies. The olanzapine/fluoxetine combination was associated with significantly (p < or = .05) greater improvement (decrease) in MADRS scores than olanzapine at weeks 2, 4, 6, and 7; than fluoxetine at weeks 2 through 5; and than nortriptyline at weeks 1 through 4. A post hoc analysis of a subgroup of patients who had an SSRI treatment failure during their current MDD episode (N = 314) revealed that the olanzapine/fluoxetine combination group had a significantly (p = .005) greater decrease in MADRS scores than the olanzapine group at endpoint. Safety data for the olanzapine/fluoxetine combination were similar to those for its component monotherapies. CONCLUSIONS: The olanzapine/fluoxetine combination did not differ significantly from the other therapies at endpoint, although it demonstrated a more rapid response that was sustained until the end of treatment. The results raised several methodological questions, and recommendations are made regarding the criteria for study entry and randomization.     

Safety and efficacy of long-acting risperidone in schizophrenia: a 12-week, multicenter, open-label study in stable patients switched from typical and atypical oral antipsychotics

BACKGROUND: The safety and efficacy of the first long-acting injectable atypical antipsychotic, risperidone, were assessed in stable patients with schizophrenia switched from oral antipsychotic medications. METHOD: Data were collected between July 1, 2001, and October 25, 2002. The study population included patients from clinics, hospitals, and physicians' offices. After a 4-week run-in period, symptomatically stable patients with schizophrenia (DSM-IV) who had been taking haloperidol (N = 46), quetiapine (N = 45), or olanzapine (N = 50) received 25 mg of long-acting risperidone. The oral antipsychotics were continued for 3 weeks after the first injection of long-acting risperidone. Injections were administered every 2 weeks at 25 mg up to a maximum dose of 50 mg for 12 weeks in this multicenter, open-label study. RESULTS: Long-acting risperidone was well tolerated. Of the 141 patients who participated in the study, the most frequently reported adverse events were insomnia (16%), headache (15%), psychosis (11%), and agitation (11%). The mean increase in body weight was 0.4 kg. No other clinically relevant laboratory abnormalities or significant electrocardiogram changes were observed during the 12-week treatment. Extrapyramidal Symptom Rating Scale total scores were reduced during treatment with long-acting risperidone. Improvements in symptoms of schizophrenia were observed with long-acting risperidone at week 4 and continued through the 12-week treatment with significant reductions in total Positive and Negative Syndrome Scale (PANSS) scores at week 8 (-2.5, p <.01) and week 12 (-3.9, p <.001). At endpoint, 37% (50/135) of these stable patients were rated as clinically improved (> or = 20% decrease in PANSS total scores). CONCLUSIONS: Switching treatment from oral antipsychotics to long-acting risperidone without an intervening period of oral risperidone was safe and well tolerated. Long-acting risperidone also significantly reduced the severity of symptoms in these stable patients with schizophrenia.     

Olfactory deficits in patients with mild cognitive impairment predict Alzheimer's disease at follow-up

OBJECTIVE: This study evaluated the predictive utility of olfactory identification deficits in patients with mild cognitive impairment for follow-up diagnosis of probable Alzheimer's disease. METHOD: Ninety outpatients with mild cognitive impairment were examined at 6-month intervals. Matched healthy comparison subjects (N=45) were examined annually. The University of Pennsylvania Smell Identification Test was given at baseline. RESULTS: Olfaction scores were lower in patients with mild cognitive impairment than in healthy comparison subjects. Seventy-seven patients were followed up; 19 were diagnosed with Alzheimer's disease by 2 years. Patients with low olfaction scores (< or =34 of 40), and patients with low olfaction scores who reported no subjective problems smelling, were more likely to develop Alzheimer's disease than other patients. In a Cox proportional hazards model adjusted for age, sex, modified Mini-Mental State score, and education, low olfaction scores did not predict time until development of Alzheimer's disease, but low olfaction scores accompanied by lack of awareness of olfactory deficits predicted time to development of Alzheimer's disease. This effect remained when attention or memory measures replaced modified Mini-Mental State score in the model. In patients with high Mini-Mental State scores (> or =27 of 30), low olfaction with lack of awareness remained a significant predictor of Alzheimer's disease. Olfaction scores of 30-35 showed moderate to strong sensitivity and specificity for diagnosis of Alzheimer's disease at follow-up. CONCLUSIONS: In patients with mild cognitive impairment, olfactory identification deficits, particularly with lack of awareness of olfactory deficits, may have clinical utility as an early diagnostic marker for Alzheimer's disease.     

Fluoxetine versus sertraline and paroxetine in major depressive disorder: changes in weight with long-term treatment

BACKGROUND: The effects of extended selective serotonin reuptake inhibitor (SSRI) treatment on weight are not well characterized. Also unknown is whether different agents have differential effects. To examine these questions, we assessed weight changes in patients randomly assigned to long-term treatment with fluoxetine, sertraline, or paroxetine. METHOD: Patients (N = 284) with major depressive disorder (DSM-IV) were randomly assigned to double-blind treatment with fluoxetine (N = 92), sertraline, (N = 96), or paroxetine (N = 96) for a total of 26 to 32 weeks. The mean percent change in weight was compared for each group, as was the number of patients who had > or = 7% weight increase from baseline. RESULTS: Patients (fluoxetine, N = 44; sertraline, N = 48; paroxetine, N = 47) who completed the trial were included in these analyses. Paroxetine-treated patients experienced a significant weight increase, fluoxetine-treated patients had a modest but nonsignificant weight decrease, and patients treated with sertraline had a modest but nonsignificant weight increase. The number of patients whose weight increased > 7% from baseline was significantly greater for paroxetine-treated compared with either fluoxetine-treated or sertraline-treated patients. CONCLUSION: Risk of weight gain during extended SSRI treatment differs depending on which SSRI is used.     

Signal-to-noise ratio of chemosensory event-related potentials.

OBJECTIVE: We investigated the influence of the number of stimuli on signal-to-noise (S/N) ratio of CSERP. METHODS: CSERP from 20 normosmic subjects were obtained in response to stimulation with two olfactory (H(2)S and PEA) and a trigeminal (CO(2)) stimulant. For each of these odors, 160 stimuli were delivered into the right nostril (duration 200ms, mean ISI 30s) using a constant-flow, air-dilution olfactometer. For each EEG recording site (Fz, Cz, Pz, C3, C4), peak-to-peak amplitude N1P2 and noise amplitude levels were determined. Subsequently, S/N ratios were calculated. RESULTS: The S/N ratios for olfactory ERP generally improved for H(2)S and PEA. For responses to PEA, S/N ratios increased significantly up to 80 averages (S/N ratio=5.6). The number of stimuli for an optimal S/N ratio for trigeminal ERP was slightly lower, i.e. 60 averages (S/N ratio=7.9). CONCLUSIONS: S/N N1P2 ratios in olfactory and trigeminal ERP significantly improve with an increasing number of responses averaged under these experimental conditions. This is mainly due to a reduction of noise level. Applying more stimuli has little additional effect on S/N ratio due to a concomitant decrease in signal amplitude. SIGNIFICANCE: An optimal S/N ratio is essential when recording CSERP in neurodegenerative disorders, where responses may be of low amplitude, and for medico-legal purposes.     

不同来源嗅鞘细胞修复脊髓损伤的效果比较

背景：研究表明嗅鞘细胞所分泌的细胞黏附分子和神经营养因子具有保护脊髓神经元和促进脊髓轴突再生的效应。 目的：比较嗅球及嗅黏膜固有层来源的嗅鞘细胞异体移植修复脊髓损伤的能力。 设计、时间及地点：随机对照动物实验,于2007-06/2008-06在西电集团医院中心实验室完成。 材料：随机选取雄性3月龄及23月龄SD大鼠各6只,分为实验组(23月龄)和对照组(3月龄),用于嗅鞘细胞的体外培养和纯化;SD大鼠30只随机分为乳鼠嗅球嗅鞘细胞移植组、正常嗅黏膜嗅鞘细胞移植组、对照组,每组10只。 方法：30只SD大鼠制造脊髓损伤模型,分别将体外培养的乳鼠和SD大鼠嗅鞘细胞进行脊髓损伤模型的异体移植,对照组不做移植。 主要观察指标：术后4,8周,进行BBB神经功能评分,诱发电位,组织病理学观察。 结果：实验过程中大鼠死亡7只,各组死亡率大致相同。移植后第4,8周时,乳鼠嗅鞘细胞移植组、正常嗅黏膜嗅鞘细胞组评分差异无显著性意义(P > 0.05),均显著高于空白对照组(P < 0.001);嗅鞘细胞移植2组评分8周高于4周(P < 0.01)。术后4周,各组动物均未引出运动诱发电位,移植后8周时,2组嗅鞘细胞移植组动物均可引出运动诱发电位,2组差异无显著性意义(P > 0.05),空白对照组动物仍未引出运动诱发电位(P < 0.001)。移植后8周,2组嗅鞘细胞移植组脊髓损伤区有较多细胞浸润,对照组细胞数目较少。 结论：来源于嗅球与嗅黏膜的嗅鞘细胞对脊髓损伤修复均有促进作用,且两者作用无明显差异。     

Effect of risperidone on behavioral and psychological symptoms and cognitive function in dementia

AIMS: This open-label study examined the efficacy and tolerability of risperidone in the treatment of aggression, agitation, and psychotic symptoms in dementia. The influence of risperidone on cognitive function was also assessed under conditions reflecting normal, daily clinical care. METHOD: A total of 34 hospital inpatients and outpatients (mean age = 76 years) with DSM-IV dementia disorders were treated with flexible doses of risperidone (0.5-2 mg/day) for 8 weeks. Assessments, conducted at baseline and after weeks 4 and 8, included the Clinical Global Impressions scale (CGI) and Neuropsychiatric Inventory (NPI) ratings. Cognitive function assessments included the Mini-Mental State Examination (MMSE) and specific measures of cognition (Age Concentration Test [AKT] and Brief Syndrome Test [SKT]). Frequency of extrapyramidal symptoms (EPS) was measured according to the Extrapyramidal Symptom Rating Scale (ESRS). RESULTS: At the end of the study, 50% of patients (N = 17) were receiving risperidone, 1 mg/day. 18% (N = 6) were receiving 0.5 mg/day, and 32% (N = 11) received > 1 mg/day (mean dose at endpoint = 1.1 mg/day). An improvement in symptoms, as measured by the CGI-Global Impression of Change scale, was reported for 82% of patients (N = 28) (59% [N = 20] much or very much improved). The frequency and severity of delusions, hallucinations, agitation/aggression, and irritability decreased as measured by the NPI. Multiplication of frequency and severity scores revealed a significant decline during the course of treatment (p < .001, end of study vs. baseline). Caregiver responses on the NPI also showed an improvement, with the mean +/- SD total score decreasing from 24.2 +/- 7.3 at baseline to 21.2 +/- 6.3 at study end (p = .002). MMSE, AKT, and SKT results indicated that there was no decrease in cognitive function during the study. Risperidone treatment was well tolerated, and no clinically relevant changes in EPS. vital signs, or weight were detected. CONCLUSION: During treatment with low-dose risperidone, behavioral and psychological symptoms improved overall in 34 patients with dementia, and cognitive function was maintained throughout the treatment period.     

Increased C-reactive protein levels during short-term hormone replacement therapy in healthy postmenopausal women.

OBJECTIVE: To study the short-term effect of unopposed oestradiol (E2) and sequentially combined hormone replacement therapy (E2 + P) on C-reactive protein (CRP) in healthy postmenopausal women. DESIGN: Prospective, randomised, placebo-controlled 12-week study. Sixty healthy. normotensive, non-hysterectomised postmenopausal women received either placebo (N = 16) or daily 2 mg micronised oestradiol, either unopposed (N = 16, E2 group) or sequentially combined with a progestagen on 14 days of each cycle (N = 28, E2+P group). Data were collected at baseline and at 4 and 12 weeks. RESULTS: CRP levels increased significantly during the 12 weeks in the E2 and the E2+P groups compared to placebo. No differences were found between the E2 group and the E2+P group [E2 and E2+P group together (N = 44) versus placebo: P = 0.01; E2 versus E2+P: P = 0.75]. To give a quantitative estimate of the increase, the median change calculated from baseline in both treatment groups together was +87% (P = 0.02) at 4 weeks, and +114% (P = 0.08) at 12 weeks, as compared to the placebo group. CONCLUSION: In healthy postmenopausal women, short-term treatment with E2 or E2+P was associated with a rapid rise in CRP concentrations. These observations raise the possibility that the increased risk of cardiovascular events is related to an initial increase in CRP levels after starting hormone replacement therapy.     

A placebo-controlled study of fluoxetine in continued treatment of bulimia nervosa after successful acute fluoxetine treatment.

OBJECTIVE: The efficacy of fluoxetine in the acute management of bulimia nervosa is well established; however, few controlled studies have examined whether continuation of pharmacotherapy provides protection from relapse. This study compared the efficacy and safety of treatment with fluoxetine versus placebo in preventing relapse of bulimia nervosa during a 52-week period after successful acute fluoxetine therapy. METHOD: Patients who met DSM-IV criteria for bulimia nervosa, purging type, were assigned to single-blind treatment with 60 mg/day of fluoxetine. After 8 weeks of treatment, patients were considered responders if they experienced a decrease > or =50% from baseline in the frequency of vomiting episodes during 1 of the 2 preceding weeks. Responders were randomly assigned to receive 60 mg/day of fluoxetine or placebo and were monitored for relapse for up to 52 weeks. Patients met relapse criteria if they experienced a return to the baseline vomiting frequency that persisted for 2 consecutive weeks. RESULTS: Of the 232 patients who entered the acute phase, 150 patients (65%) met response criteria and were randomly assigned to receive fluoxetine (N=76) or placebo (N=74). Fluoxetine-treated patients exhibited a longer time to relapse than placebo-treated patients. Quantitative analysis of other efficacy measures, including frequency of vomiting episodes, frequency of binge eating episodes, Clinical Global Impression severity and improvement scores, the patient's global impression score, and Yale-Brown-Cornell Eating Disorder Scale score, indicated that the efficacy of fluoxetine treatment was statistically superior, compared to placebo. There were no clinically relevant differences in safety between groups. Attrition in this study was high, especially in the first 3 months after random assignment to treatment groups. CONCLUSIONS: Continued treatment with fluoxetine in patients with bulimia nervosa who responded to acute treatment with fluoxetine improved outcome and decreased the likelihood of relapse.     

Effect of multilevel botulinum toxin a and comprehensive rehabilitation on gait in cerebral palsy

To evaluate the effect of multilevel botulinum toxin A and comprehensive rehabilitation on gait pattern, muscle length, and spasticity, a multicenter randomized trial was performed in 46 children with spastic cerebral palsy who walk with flexed knees. Their mean age was 8.0 years (range 4 to 11 years). They were randomly allocated to the intervention group (multilevel botulinum toxin A and comprehensive rehabilitation) or the control group (usual care). After 6 weeks, a significant treatment effect in the intervention group was observed on: improved knee extension during midstance and terminal swing (7 degrees and 5 degrees , P < 0.01, respectively); hip rotation during terminal swing (4 degrees , P = 0.02); gait score (1.7, P < 0.01); decreased spasticity in hamstrings (11 degrees , P < 0.01), gastrocnemius (6 degrees , P = 0.01), and soleus (5 degrees , P = 0.02); and increased muscle length in hamstrings (9 degrees , P < 0.01) and gastrocnemius (5 degrees , P < 0.01). The improved muscle length was maintained up to 24 weeks. This study demonstrated that multilevel botulinum toxin A and comprehensive rehabilitation improves knee extension during gait, increases muscle length, and decreases spasticity in injected muscles after 6 weeks in children who walk with flexed knees. Although the effect on muscle length was maintained after 24 weeks, the effect on gait and spasticity had disappeared.     

Neuroleptic-induced parkinsonism is associated with olfactory dysfunction

Objective   There is increasing evidence for olfactory deficits in patients with extrapyramidal disorders, but little is known about their occurrence in patients with drug-induced extrapyramidal symptoms (EPS). The present study was performed to investigate olfactory function in depressed patients with drug-induced parkinsonism under treatment with D2-blocking neuroleptic drugs compared to depressed controls on similar neuroleptic dose without EPS (no-EPS), and neuroleptic-naive depressed controls (no-NL). Methods   A total of 79 depressed patients with (N = 59) and without psychotic features (N = 20) were included in the study. Psychotic patients were treated with D2 blocking neuroleptic drugs. Of the neuroleptic-treated patients, 15 developed EPS. In all patients psychophysical olfactory testing was performed using “Sniffin’ Sticks” which included assessment of odor thresholds for phenylethylalcohol (PEA), odor identification, and odor discrimination. Results   Patients in the EPS group had significantly lower olfactory scores than patients in the no-EPS or no-NL groups. Patients in the no-NL and no-EPS groups were not significantly different from each other in terms of olfactory function. Using partial correlations controlling for the patients’ age, significant correlations were observed for EPS patients between severity of EPS and odor thresholds and odor identification, but not for odor discrimination. This indicated that olfactory function decreased with increasing severity of EPS symptoms. Conclusions   Our data show that olfactory deficits may be drug-induced in patients with primary affective disorder with a sensitivity toward developing EPS.     

Lesions of the olfactory pathways affecting neophobia and learned aversion differentially

The contribution of ascending olfactory pathways in neophobia and learned aversion to the same food was investigated in male rats bearing lesions of both olfactory peduncles, or one olfactory peduncle and the opposite lateral olfactory tract or anterior limb of the anterior commissure. The animals were fed on usual stock diet (S) offered as a choice with novel vanilla food (V) on test days: during neophobia (N), then before and after aversive conditioning (Aa, At). Daily food intake was measured, and the preference was expressed as V/(V + S). Experiment 1 included a neophobia test, before aversive conditioning (3 mEq/kg LiCl, i.p.). In Experiment 2, aversion only was studied (0.9 mEq/kg). In the neophobia test, the preference ratio was 7% in unoperated controls, and 43-52% in the 3 lesioned groups. The same controls had preference ratios equal to 64% and 22%, before and after aversive learning. Similar drops were observed for any lesioned group in Expt. 1. The decrease was less obvious, although significant, in rats of Expt. 2 with asymmetric lesions; those with both olfactory peduncles cut through maintained the same preference ratio (48%) before and after LiCl treatment. The data are interpreted assuming that: (1) lateral olfactory tract and anterior commissure both contribute to information processing in neophobia and aversion; (2) olfactory cues subserve neophobia prepotently; and (3) one cannot account for the sensory determinism of neophobia and aversion calling for a single mechanism.     

Prolactin levels in schizophrenia and schizoaffective disorder patients treated with clozapine, olanzapine, risperidone, or haloperidol

BACKGROUND: Prolactin levels are elevated to varying degrees by antipsychotics. Prolactin elevations may result in sexual and other adverse effects, and they may be related to antipsychotic effects. We used the data collected in a trial of antipsychotics to study the differential effect of these drugs on prolactin level, to explore the relation between clinical effects and prolactin level, and to determine the relationship between plasma levels of antipsychotics and prolactin level. METHOD: Treatment-resistant patients (133 men, 24 women) diagnosed with DSM-IV schizophrenia or schizoaffective disorder participated in a double-blind, randomized, 14-week trial comparing clozapine (N = 40), olanzapine (N = 39), risperidone (N = 41), and haloperidol (N = 37). Plasma levels of prolactin and antipsychotics were determined at baseline and at weeks 5, 8, 10, 12, and 14 during the trial. Clinical effects were measured with the Positive and Negative Syndrome Scale and the Extrapyramidal Symptom Rating Scale. Statistical analyses were limited to the 75 men for whom repeated prolactin levels were available. Data were gathered from June 1996 to December 1999. RESULTS: Risperidone caused significant elevation of prolactin levels (p <.05) that appeared to be dose-dependent. Clozapine and olanzapine were associated with decreases of prolactin, whereas haloperidol led to a minor, nonsignificant increase. Plasma olanzapine and prolactin levels were correlated. Prolactin levels were not related to clinical improvement or extrapyramidal side effects. CONCLUSION: Antipsychotics show major differences in their effects on prolactin, and risperidone has clearly the most robust effect.     

嗅鞘细胞移植治疗脊髓损伤的临床验证

背景: 一系列基础研究证实在动物脊髓损伤的模型中,嗅鞘细胞移植能够促进脊髓损伤的再生和恢复脊髓的部分神经功能。部分临床实验证明嗅鞘细胞的移植的确能改善脊髓损伤患者的神经功能,从而改善其生活质量。 目的：验证嗅鞘细胞移植对脊髓损伤患者神经功能修复的作用及安全性。 方法：取流产胚胎嗅球并消化成为单个嗅鞘细胞,培养纯化2周左右,制成嗅鞘细胞悬液。选择脊髓损伤患者213例,全麻下将制备好的嗅鞘细胞悬液采用区域性多靶点注射方法移植于损伤脊髓的周围。采用ASIA量表对患者移植前1d及移植后3周~2个月进行评分,评价患者脊髓恢复状况。 结果与结论：所有患者的脊髓神经功能于术后3周均有不同程度的改变,脊髓功能评分及感觉与运动功能均较移植前明显提高(P < 0.001),且随时间延长呈不断改善趋势;最长患者随访5年,未见已恢复的神经功能 减退及移植不良反应。证实嗅鞘细胞移植对脊髓损伤患者的神经功能恢复有促进作用,可以部分恢复及改善其部分脊髓神经功能,且治疗方法安全。     

Effects of methylphenidate on olfaction and frontal and temporal brain oxygenation in children with ADHD

Objective

Olfaction and attention-deficit-/hyperactivity disorder (ADHD) are mediated by dopamine metabolism and fronto-temporal functioning converging in recent findings of increased olfactory sensitivity in children with ADHD modulated by methylphenidate (MPH) and altered frontal and temporal oxygenation in adults with ADHD.

Method

We investigated olfactory sensitivity, discrimination, and identification (Sniffin’ Sticks) in 27 children and adolescents with ADHD under chronic MPH medication and after a wash-out period of at least 14 half-lives in balanced order and 22 controls comparable for handedness, age, and intelligence. In addition, inferior frontal and temporal oxygenation was measured by means of functional near-infrared spectroscopy (fNIRS) during the presentation of 2-phenylethanol. Group differences in regard to sex distribution were statistically controlled for by analysis of covariance.

Results

Patients did not differ from controls in any olfactory domain under treatment with MPH. Cessation of medication led to a significant increase in olfactory discrimination. Controls displayed typical inferior frontal and temporal brain activity in response to passive olfactory stimulation, while brain oxygenation was diminished in the patient group when assessed without medication. Under medication ADHD patients showed a trend for a normalisation of brain activity in the temporal cortex.

Conclusions

The here reported effects of MPH cessation on olfactory discrimination and frontal and temporal oxygenation along with previous findings of increased olfactory sensitivity in medication-naïve ADHD children and its normalisation under chronic MPH treatment lead to the conclusion that MPH exerts differential chronic effects vs. acute cessation effects on altered olfactory function in ADHD. These effects are most probably mediated by modulation of the dopaminergic system.     

Streptozotocin-induced diabetes duration is important to determine changes in the number and basophily of myenteric neurons

The aim of present study was to evaluate the number and basophily of cell bodies of myenteric neurons in the ileum of rats with diabetes mellitus induced by streptozotocin. Four groups of rats were used: diabetes was induced in two (D) whereas the other two worked as controls (N). Animals were sacrificed six (6N, 6D) or nineteen (19N, 19D) weeks after diabetes induction. A segment of the terminal portion of the ileum of each rat was obtained and stained with Giemsa's solution, for whole-mount preparation studies. Forty fields were analyzed in each animal, and the number and basophily intensity of cell bodies were recorded. After counting, the following mean numbers of neurons/mm2 were obtained: 6N=593.1 +/- 95.75, 6D=639.1 +/- 130.8, 19N=580.1 +/- 175.6 and 19D=402.0 +/- 144.8. The analysis of basophily shown that highest frequency of neurons with weak/intermediary basophily was verified in 6D group (55.3%), whereas the groups 6N, 19N e 19D presented 38%, 36% e 40% respectively. The statistical analysis showed that a long period is necessary to decrease the number of neurons/mm2 in the rat ileum after diabetes induction, and that there was a reduction in basophily intensity in diabetic rats after 6 weeks of treatment, and such cells do not recover after a longer period (19 weeks).