Role of hepcidin in murine brain iron metabolism.

Brain iron homeostasis is maintained by a balance of both iron uptake and release, and accumulating evidence has revealed that brain iron concentrations increase with aging. Hepcidin, an iron regulatory hormone produced by hepatocytes in response to inflammatory stimuli, iron, and hypoxia, has been shown to be the long-sought hormone responsible for the regulation of body iron balance and recycling in mammals. In this study, we report that hepcidin is widely expressed in the murine brain. In cerebral cortex, hippocampus and striatum, hepcidin mRNA levels increased with aging. Injection of hepcidin into the lateral cerebral ventricle resulted in decreased Fpn1 protein levels in cerebral cortex, hippocampus, and striatum. Additionally, treatment of primary cultured neurons with hepcidin caused decreased neuronal iron release and Fpn1 protein levels. Together, our data provide further evidence that hepcidin may be involved in the regulation of brain iron metabolism.

Association of human micro-opioid receptor gene polymorphism A118G with fentanyl analgesia consumption in Chinese gynaecological patients.

One hundred and seventy-four Chinese gynaecology patients were studied for the impact of A118G polymorphism in the micro-opioid receptor gene (OPRM1) on pain sensitivity and postoperative fentanyl consumption. Pre-operatively, the pain threshold and pain tolerance threshold were measured using electrical stimulation. A118G polymorphism was genotyped using the polymerase chain reaction-restriction fragment length polymorphism method. Intravenous fentanyl patient-controlled analgesia provided postoperative pain management, assessed using a visual analogue scale and fentanyl consumed in the first 24 h after surgery was noted. We found the prevalence of G118 allele was 31.3%. The A118G polymorphism had a gene-dose-dependent effect on electrical pain tolerance threshold. Fentanyl consumption was also significantly different in patients with different OPRM1 genotypes (homozygotes for 118G consumed more than did heterozygotes or homozygotes for 118A). Fentanyl consumption increased in accordance with the number of 118G alleles. We conclude that OPRM1 gene analysis may help predict individual opioid sensitivity and so optimise postoperative pain control.

Brain iron accumulation exacerbates the pathogenesis of MPTP-induced Parkinson's disease.

Brain iron levels are significantly increased in Parkinson's disease (PD) and iron deposition is observed in the substantia nigra (SN) of PD patients. It is unclear whether iron overload is an initial cause of dopaminergic neuronal death or merely a byproduct that occurs in the SN of PD patients. In this study, ceruloplasmin knockout (CP-/-) mice and mice receiving an intracerebroventricular injection of ferric ammonium citrate (FAC) were selected as mouse models with high levels of brain iron. These mice were administered with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) by intraperitoneal injection. Their behavior and the dopaminergic neuron damage to their substantia nigra pars compacta (SNpc) were assessed. These findings suggest that the injection of FAC or the absence of the CP gene may exacerbate both the observed apoptosis of TH-positive neurons and the behavioral symptoms of the MPTP-treated mice. The intracerebroventricular injection of deferoxamine (DFO) significantly alleviated the neuronal damage caused by MPTP in CP-/- mice. Furthermore, our findings suggest that the increased nigral iron content exacerbates the oxidative stress levels, promoting apoptosis through the Bcl-2/Bax pathway and the activated caspase-3 pathway in the brain. Therefore, iron overload in the brain exacerbates dopaminergic neuronal death in SNpc and leads to the onset of PD.

Neuroprotective effects of ginkgetin against neuroinjury in Parkinson's disease model induced by MPTP via chelating iron.

Disruption of neuronal iron homeostasis and oxidative stress are closely related to the pathogenesis of Parkinson's disease (PD). Ginkgetin, a natural biflavonoid isolated from leaves of Ginkgo biloba L, has many known effects, including anti-inflammatory, anti-influenza virus, and anti-fungal activities, but its underlying mechanism of the neuroprotective effects in PD remains unclear. The present study utilized PD models induced by 1-methyl-4-phenylpyridinium (MPP(+)) and 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) to explore the neuroprotective ability of ginkgetin in vivo and in vitro. Our results showed that ginkgetin could provide significant protection from MPP(+)-induced cell damage in vitro by decreasing the levels of intracellular reactive oxygen species and maintaining mitochondrial membrane potential. Meanwhile, ginkgetin dramatically inhibited cell apoptosis induced by MPP+ through the caspase-3 and Bcl2/Bax pathway. Moreover, ginkgetin significantly improved sensorimotor coordination in a mouse PD model induced by MPTP by dramatically inhibiting the decrease of tyrosine hydroxylase expression in the substantia nigra and superoxide dismutase activity in the striatum. Interestingly, ginkgetin could strongly chelate ferrous ion and thereby inhibit the increase of the intracellular labile iron pool through downregulating L-ferritin and upregulating transferrin receptor 1. These results indicate that the neuroprotective mechanism of ginkgetin against neurological injury induced by MPTP occurs via regulating iron homeostasis. Therefore, ginkgetin may provide neuroprotective therapy for PD and iron metabolism disorder related diseases.

Beta-endorphin- and GABA-mediated depressor effect of specific electroacupuncture surpasses pressor response of emotional circuit.

It has been proved that input of specific electroacupuncture (EA) can activate beta-endorphin(beta-EP)ergic and noradrenergic neurons projecting to the rostral ventrolateral medulla (RVL), the latter acting upon the RVL-GABAergic interneurons, thereby produce depressor effect. The present study further shows that: (1) The EA depressor effect is strong enough to surpass the pressor response of the AC (nucleus amygdaloideus centralis)-emotional circuit, (2) both beta-endorphin (beta-EP) and GABA in the RVL mediate the EA antagonistic effect, (3) the EA effect does not take place in the AC and paraventricular nucleus (two key nuclei besides the RVL, which also have beta-EPergic input) in the emotional circuit.

Mechanisms underlying pressor response of subfornical organ to angiotensin II.

In urethane-anesthetized rats, microinjection of angiotensin II (AII) into either the subfornical organ (SFO), nucleus paraventricularis (NPV), or rostral ventrolateral medulla (RVL), respectively, all induced pressor responses, but the heart rate remained unchanged. Preinjection of [Sar1, Thr8]-angiotensin II (ST-AII, an AII antagonist) into bilateral NPV blocked the SFO-pressor response to AII. Bilateral RVL pretreated with ST-All markedly attenuated the pressor response of the SFO or NPV to AII. Hexamethonium or methyl atropine (IV) also reduced the SFO-pressor response. The results show that All can activate the SFO, NPV, and RVL successively, thereby inducing the pressor response; both excitation of sympathetic nerves and inhibition of the cardiac vagus are involved in this response.

Factors affecting local or regional recurrence in breast cancer.

Between 1975 and 1989, 535 patients with infiltrating ductal carcinoma of the breast in various clinical stages were treated by modified radical mastectomy and axillary node clearance, followed by chemotherapy, endocrine therapy or radiotherapy. Median follow-up was 3 years (5 months to 15 years). Fifty-eight local or regional recurrences occurred. The 5-year and 10-year actuarial risks of breast recurrences were 14% +/- 2% and 23% +/- 4%, respectively. Using multivariate analysis with the Cox regression model, the most important multivariate-adjusted independent contributing factors to local or regional breast recurrences were age less than or equal to 40 (p less than 10(-4), relative risk = 2.94), positive lymph nodes greater than 3 (p less than 10(-3), relative risk = 2.57), and multicentricity (p = 0.044, relative risk = 2.73). The overall 5-year survival rate of recurrent patients was 64 +/- 7%, and was significantly worse when breast recurrence occurred in the first 18 months after operation. The multivariate-adjusted relative risk of death for early recurrence was 4.35 (p = 0.04). The unadjusted 5-year survival rate for early recurrence was 58% +/- 1%, and 85% +/- 8% for late recurrence. This study confirms the relationship between young age and low breast control rates. It emphasizes the adverse prognosis of early breast recurrences as compared to the relatively favorable outcome of late recurrences.

[Role of brain angiotensin II system in subfornical organ-pressor responses].

We studied the role of brain angiotensin II in subfornical organ-pressor responses using urethane-anesthetized, tubocurarine-immobilized rats, and the present work obtained the following findings: (1) angiotensin II (A II) induced pressor responses by injection into several brain regions: either subfornical organ (SFO),nucleus paraventricularis (NPV) or its projection areas, including rostral ventrolateral medulla (RVLM),periaqueductal gray matter (PAG) and locus coeruleus (LC); (2) SFO pressor responses were markedly attenuated by preinjection of [Sar(1),Thr(8)]-A II (ST-A II, an A II antagonist) into bilateral NPV or RVLM,while NPV pressor responses were suppressed by ST-A II injection into the RVLM; (3) both SFO- and NPV-pressor responses were decreased by ST-A II preinjection into bilateral PAGL; and (4) ST-A II preinjection into bilateral LC could only attenuate NPV pressor responses without affecting SFO pressor responses. Taken together with our previous findings that the RVLM mediates the pressor responses of the PAG and LC, the present results indicate that A II activates A II ergic neurons in the SFO may evoke pressor responses by acting upon RVLM through NPV and NPV- PAG -RVLM system. Whereas NPV- LC- RVLM system was not involved in the SFO pressor responses.

[Pressor response to glutamate-injection into hypothalamic paraventricular nucleus and its relation to pressor response of locus coeruleus and depressor response of A1].

In urethane-anesthetized, tubocurarine-immobilized and artificially ventilated rats, microinjection of L-glutamate (Glu) into hypothalamic paraventricular nucleus (NPV) or locus coeruleus (LC) induced a pressor response. The LC-pressor response could be attenuated by preinjection of phentolamine or propranolol into bilateral NPV; Preinjection of phentolamine or bicuculline into bilateral NPV could also attenuate the depressor effect of A1-excitation by Glu, but preinjection of propranolol had no such effect; suggesting that the LC-pressor or A1-depressor effect is mediated partly by NPV, and GABAergic inhibitory interneurons in NPV may be involved in A1-depressor response.

[Roles of vagal projection areas afferents on vagal input-evoked depressor response].

Vagal afferents project directly or indirectly to several brain areas. In urethane-anesthetized and bilaterally vagotomized rats, either procaine injection into the nucleus tractus solitarii (NTS) or beta-endorphin antiserum injection into the rostral ventrolateral medulla (RVL) markedly decreased the depressor (DpV) and bradycardia response to stimulation of cervical vagal afferents, while propranolol (or beta-endorphin antiserum) injection into the nucleus paraventricularis and procaine injection into the area postrema had no significant effect. In left vagotomized rats, the DpV remained unchanged after methyl atropine (i.v), but the bradycardia response during the DpV was attenuated. Since our previous study has shown the NTS can induce a depressor response via its beta-endorphinergic projections to RVL, the above results suggest that the inhibitory effect of vagal afferents on the RVL-sympathoexcitatory neurons via NTS beta-endorphinergic neurons represents one aspect of the mechanism underlying DpV.

Role of regulatory peptide in pathogenesis of shock.

The present study evaluated the pathogenetic roles of three kinds of regulatory peptide. The results showed that (i) plasma endothelin (ET) level elevated significantly in septic shock rats, persistent intravenous drip of low doses ET caused development of shock state in normal rats and the irreversible outcome of light hemorrhagic shock. Furthermore, i. v. administration of specific ET-antiserum was significantly effective to septic shock rats. (ii) Plasma calcitonin gene-related peptide (CGRP) increased by 260% in septic shock rats, i. v. drip of low doses CGRP both in early and late sepsis were effective to shock rats. (iii) Angiotensin-II (ANG-II) contents of heart and aorta increased dramatically both in early and late septic shock, and inhibiting its increase with Captopril in late sepsis significantly improved the shock state, but results were inverse in early sepsis. It could be concluded that ET was one of the most important factors participating in the pathogenesis of shock, CGRP had a compensatory regulatory role in shock and the role of tissue ANG-II was different during different periods of shock.

Study of the OPRM1 A118G genetic polymorphism associated with postoperative nausea and vomiting induced by fentanyl intravenous analgesia.

BACKGROUND: Genetic polymorphisms of the µ-opioid receptor gene OPRM1 A118G have been shown to influence opioid efficacy. The association of the OPRM1 A118G genetic polymorphism with side effects, such as nausea and vomiting, caused by opioids during analgesia has not been well-represented by the literature . This study aimed to investigate whether the genetic polymorphism of OPRM1 A118G contributed to the variability in nausea and vomiting during fentanyl analgesia in patients undergoing total abdominal hysterectomy or myomectomy. METHODS: One hundred sixty-five women, of Han nationality, aged 20-50 yrs, of ASA I or II, and scheduled for elective total abdominal hysterectomy or myomectomy under general anesthesia were enrolled. Intravenous fentanyl, patient-controlled analgesia was provided postoperatively for pain control. The presence and scores of postoperative nausea and vomiting for 24 hours were recorded and measured using rating scales. Pain was measured with a visual analog scale, and fentanyl consumption over 24 hours was recorded, as well. Genotyping of the A118G allele was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and patients were divided into three groups according to their genotype. RESULTS: The frequency of the A118G allele was 32.4% for the patients in this study. Patients homozygous for 118G required more fentanyl to achieve adequate pain relief compared with the other two patient groups (patients homozygous for 118A and heterozygous). However, there were no statistically significant differences among the frequencies and scores of nausea and vomiting. CONCLUSION: OPRM1 A118G has no effect on the individual variation of postoperative nausea and vomiting, the side effects of fentanyl analgesia, in Chinese women undergoing gynecologic surgery.

Sheathless capillary electrophoresis/electrospray mass spectrometry using a carbon-coated tapered fused-silica capillary with a beveled edge.

A tapered capillary tip containing a beveled edge was developed for use in sheathless capillary electrophoresis/electrospray mass spectrometry (CE/ESI-MS). The optimal flow rate of a 75-microm-i.d., 90-microm-o.d. beveled tapered capillary tip was similar to a conventional flat tapered tip with a 25-microm orifice. Using a mixture of coptisine, berberine, and palmatine chloride, the sheathless CE/ ESI-MS sensitivity of a beveled 75 microm tapered tip capillary was found to be similar to a 25 microm flat tip. Although both tips offer similar CE/ESI-MS sensitivity, the beveled tapered capillary tip is more rugged and durable than a conventional 25-microm tapered capillary because of the larger outside diameter and inside diameter. To make electrical contact, the capillary tip was smeared with paint marker followed by the application of a carbon coating using a graphite pencil. Using this refined carbon-coating procedure, the capillary tip can be operated with aprotic solvents.