The muscarinic M1/M4 receptor agonist xanomeline exhibits antipsychotic-like activity in Cebus apella monkeys.

Xanomeline is a muscarinic M(1)/M(4) preferring receptor agonist with little or no affinity for dopamine receptors. The compound reduces psychotic-like symptoms in patients with Alzheimer's disease and exhibits an antipsychotic-like profile in rodents without inducing extrapyramidal side effects (EPS) at therapeutically relevant doses. In the present study, we examined whether the xanomeline-induced functional dopamine antagonism found in rodent studies could also be observed in nonhuman primates. In addition, we studied whether the lack of EPS observed in rodents also applies to primates. To this end, we investigated the effects of xanomeline on the behavior induced by D-amphetamine and (-)-apomorphine in drug-naive Cebus apella monkeys. Antipsychotic compounds antagonize amphetamine-induced motor unrest and stereotypies in this species. Xanomeline inhibited D-amphetamine-induced motor unrest, stereotypies and arousal as well as apomorphine-induced stereotypies and arousal in drug-naive Cebus apella monkeys. Xanomeline did not induce EPS but vomiting occurred in some monkeys at high doses, in accordance with emetic events observed in Alzheimer patients following xanomeline administration. Even when xanomeline was tested in EPS-sensitized Cebus apella monkeys, EPS were not observed at the dose range of xanomeline used in the D-amphetamine-apomorphine combination study (0.5-3 mg/kg). However, when xanomeline was tested at 4 mg/kg, moderate dystonia was seen in two out of three monkeys. It is concluded that xanomeline inhibits D-amphetamine- and (-)-apomorphine-induced behavior in Cebus apella monkeys at doses that do not cause EPS. These data further substantiate that muscarinic receptor agonists may be useful in the pharmacological treatment of psychosis.     

A quality assessment tool to evaluate tocolytic studies

Over the past 15 years, the use of β-agonists has declined worldwide. Following the Royal College of Obstetricians and Gynaecologists guidelines in 2002, clinicians in the UK and beyond were faced with the dilemma of continuing to use β-agonists, desist from using tocolytic therapy completely or choosing to change to atosiban or calcium channel blockers (CCBs). While grade A level 1 evidence exists to show that atosiban is significantly more efficacious than placebo and significantly safer than β-agonists for the treatment of spontaneous preterm labour, the evidence for CCBs, such as nifedipine, is much less robust and no placebo-controlled trials have been performed. Published studies on nifedipine are largely investigator-led studies of small sample size, which lack sufficient power. As a result, most of the evidence has been based on meta-analyses of these studies, which look retrospectively at pooled data and are only as good as the quality of the studies included. In light of this, a tool was developed to produce a systematic review of studies on tocolytic effectiveness, which can and should be applied to all tocolytics and which considered both method- and topic-specific markers of quality. In the process of applying this tool to nifedipine, an extensive literature search identified 31 studies for a systematic review of the quality of nifedipine studies assessed by eight paired reviewers with wide experience in the subject of spontaneous preterm labour and preterm birth. Forty topic- and method-specific items of quality were assessed. The paucity of good quality studies of nifedipine used for the treatment of spontaneous preterm labour should be highlighted in meta-analyses or systematic reviews, which measure efficacy and should limit and influence the degree to which recommendations and guidelines are made on the basis of such studies.     

Impaired iron homeostasis in Parkinson's disease

Despite physiological systems designed to achieve iron homeostasis, increased concentrations of brain iron have been demonstrated in a range of neurodegenerative diseases. These including the parkinsonian syndromes, the trinucleotide repeat disorders and the dementia syndromes. The increased brain iron is confined to those brain regions most affected by the degeneration characteristic of the particular disorder and is suggested to stimulate cell damage via oxidative mechanisms. Changes in central iron homeostasis have been most closely investigated in PD, as this disorder is well characterised both clinically and pathologically. PD is associated with a significant increase in iron in the degenerating substantia nigra (SN) and is measureable in living PD patients and in post-mortem brain. This increase, however, occurs only in the advanced stages of the disease, suggesting that this phenonoma may be a secondary, rather than a primary initiating event, a hypothesis also supported by evidence from animal experiments. The source of the increased iron is unknown but a variety of changes in iron homeostasis have been identified in PD, both in the brain and in the periphery. The possibility that an increased amount of iron may be transported into the SN is supported by data demonstrating that one form of the iron-binding glycoprotein transferrin family, lactotransferrin, is increased in surviving neurons in the SN in the PD brain and that this change is associated with increased numbers of lactotransferrin receptors on neurons and microvessels in the parkinsonian SN. These changes could represent one mechanism by which iron might concentrate within the PD SN. Alternatively, the measured increased in iron might result from a redistribution of ferritin iron stores. Ferritin is located in glial cells while the degenerating neurons do not stain positive for ferritin. As free radicals are highly reactive, it is unlikely that glial-derived free radicals diffuse across the intracellular space in sufficent quantities to damage neuronal constituents. If intracellular iron release contributes to neuronal damage it seems more probable that an intraneuronal iron source is responsible for oxidant-mediated damage. Such a iron source is neuromelanin (NM), a dark-coloured pigment found in the dopaminergic neurons of the human SN. In the normal brain, NM has the ability to bind a variety of metals, including iron, and increased NM-bound iron is reported in the parkinsonian SN. The consequences of these phenomena for the cell have not yet been clarified. In the absence of significant quantities of iron NM can act as an antioxidant, in that it can interact with and inactivate free radicals. On the other hand, in the presence of iron NM appears to act as a proxidant, increasing the rate of free radical production and thus the oxidative load within the vulnerable neurons. Given that increased iron is only apparent in the advanced stages of the disease it is unlikely that NM is of importance for the primary aetiology of PD. A localised increase in tissue iron and its interaction with NM may be, however, important as a secondary mechanism by increasing the oxidative load on the cell, thereby driving neurodegeneration.     

中德初级卫生保健的比较研究

初级卫生保健无论在发达国家还是发展中国家都是卫生保健系统的一个明显特征。根据Starfield提出的不同国家初级卫生保健发展状况要素,对中德两国的初级卫生保健人员、资金来源和支付方式、服务方式及改革和发展趋势等进行比较研究。通过分析借鉴德国的初级卫生保健和全科医生制度,探讨我国初级卫生保健的实现途径,以促进卫生体制的深化改革。     

Vasopressin in anergic schizophrenia

Sixteen out of 19 patients suffering from chronic anergic schizophrenia completed a placebo-controlled crossover study with lysine-8-vasopressin (LVP), following a schedule of 1 week of placebo, 3 weeks of LVP, starting with 22.5 IU/day, gradually increased to 67.5 IU/day, and finally 4 weeks of placebo. The psychia state was evaluated with the Brief Psychiatric Rating Scale (BPRS), during weekly live interviews, and following videotaped BPRS interviews at the beginning and end of the LVP period, and at the end of the final placebo period. Symptoms of parkinsonism and tardive dyskinesia were also videotaped during a standardized examination at the same intervals. The videotapes were subsequently randomized and evaluated blindly. The results of the live interviews showed a significant (P<0.05) decrease in the BPRS anergic factor after 2 and 3 weeks of LVP treatment, but there were no changes in any single item, other BPRS factors, or the BPRS total score. The results of the videotape evaluations showed that the BPRS thinking disorder factor was significantly (P<0.05) decreased after 3 weeks of LVP, whereas the total BPRS score was unchanged. No consistent changes in parkinsonism or tardive dyskinesia were found. Although side effects were few, six patients became agitated or aggressive during the LVP treatment. The beneficial effect on thought disorder and anergia, but the absence of global effects on the schizophrenic syndrome, illustrates the need for further research with other vasopressin analogues. The advantages and disadvantages of live and videotaped psychiatric interviews are also discussed.     

Allgemeine Therapie

Ohne Zusammenfassung     

Adjuvante und definitive Radio-Chemo-Therapie des Vulvakarzinoms

Vulvar cancer is a relatively rare disease with an incidence of 4% of all gynaecologic cancers. Early vulvar cancers are treated by radical local excision of the tumour and inguinal lymph node dissection. The most important prognostic factors are the presence of lymph node metastasis and the magnitude of surgical margins. In high-risk cases, adjuvant radiotherapy can reduce the local recurrence rate and may improve survival. In advanced stages, combined chemoradiation reduces tumour size and improves the chance of partial or complete remission.     

Expression of specific granule markers on the cell surface of neutrophil cytoplasts

The widespread assumption that cytoplasts generated from human polymorphonuclear leukocytes (PMNs) are vesicles consisting solely of cytoplasm surrounded by plasma membrane and devoid of granule activity remains to be tested. PMN cytoplasts were prepared by centrifugation of intact cells on a Ficoll step gradient in the presence of cytochalasin B. Two granule membrane markers, Mol, a fluorometrically detectable antigen, and cytochrome b, both of which have been shown to translocate to the plasma membrane during granule release, were compared for their activity in cytoplasts and intact PMNs. We found that the amount of Mol detected on the plasma membrane of intact PMNs, as compared with other membrane markers (such as antigens LFA-1 and beta 2m), increased 1.6- fold upon exposure of PMNs to Ficoll plus cytochalasin B prior to centrifugation. Another twofold increase in Mol expression occurred upon cytoplast preparation. Release of the granule enzymes, vitamin B12- binding protein, and lysozyme were also followed and correlated well (r = .78 and .92) with the amount of Mol antigen present on the cell surface. Cytochrome b was also found to be higher (1.4-fold) on plasma membranes isolated from cytoplasts than on plasma membranes isolated from intact control cells. These results indicate that some fusion of granule membranes and plasma membranes occurred during treatment of PMNs with Ficoll plus cytochalasin b and during cytoplast preparation.