硝苯吡啶对急进高原现场幼猪氧动力学的影响

目的 :了解硝苯吡啶 (Nifedipine ,NF)对急性缺氧幼猪氧动力学的影响。方法 :利用右心漂浮导管法对快速进入高原急性缺氧幼猪应用NF后氧动力学的变化进行观察。结果 :应用NF后 ,急性缺氧幼猪的肺动脉平均压 (mPAP)、肺血管阻力 (PVR)显著降低 (其中mPAP :P <0 .0 1,PVR :P <0 .0 0 1) ;心输出量 (CO)、SaO2 、PaO2 、氧输送 (DO2 )、氧消耗 (VO2 )、氧摄取率 (O2Ext)显著提高 (CO :P <0 .0 1,SaO2 、PaO2 、DO2 、VO2 、O2Ext:P <0 .0 0 1)。结论 :NF能降低急性缺氧幼猪的PVR ,通过改变CO而提高组织的DO2 、VO2 ,改善组织因缺氧引起的氧代谢障碍。     

钙拮抗剂抑制大鼠肾草酸钙结石生成的实验研究

目的观察不同剂量硝苯地平灌喂对大鼠肾草酸钙结石生成的影响。方法选用60只雄性SD大鼠,体重200~250g,随机分为6组,分别为空白对照组、单纯硝苯地平组、单纯诱石组、诱石 3、6、10mg·kg-1·d-1硝苯地平干预组,每组各10只。应用乙二醇诱导大鼠产生肾草酸钙结石,4周后观察大鼠肾小管结晶沉积情况、肾组织自由基水平、细胞凋亡情况和大鼠血和尿多项生化指标的变化。结果与单纯诱石组相比,各硝苯地平干预组的肾小管草酸钙结晶评分分别降低37.0%、55.6%、66.7%(P均<0.05),肾小管上皮细胞凋亡数分别减少30.2%、44.6%、48.7%(P均<0.05),两者有显著相关性(r=0.8251);肾组织中MDA含量也分别减少14.5%、20.4%、21.8%,而SOD活性增加3.5%、8.7%、12.6%(P均<0.05);量效关系呈正相关。结论硝苯地平通过减少高尿草酸所致的肾小管上皮细胞凋亡,能有效抑制饮用诱石剂大鼠的肾小管结石生成。     

中药敷脐治疗原发性痛经前列腺素表达研究

目的:研究中药敷脐治疗原发性痛经的临床效果以及对前列腺素(PgF_(2α)、PgE_2)表达的影响。方法:将205例患者随机分成两组,观察组104例,采用自制中药药膏外敷脐部治疗;对照组101例,采用硝苯地平治疗。结果:中药敷脐治疗后PgF_(2α)和PgE_2的浓度下降到正常范围,与对照组有统计学差异(P<0.01);中药敷脐治疗有效率为91.35%(95/104)明显优于硝苯地平44.55%(45/101)(P<0.01)。结论:中药敷脐治疗原发性痛经,疗效佳,无明显毒副作用,且用药经济,值得临床推广应用。     

Multiple Intrapulmonary Arteriovenous Fistulas in Childhood

Pulmonary arteriovenous fistulas (AVFs) are a rare but recognized cause of cyanosis in childhood. Lesions may be acquired as in hepatopulmonary syndrome or they may be congenital, particularly in association with certain multisystem disorders. Large fistulas are more common than multiple small connections. Two cases, both boys, presenting in the first decade of life are described. ``Bubble' echocardiography was the most telling investigation and strongly suggested the presence of AVFs in both cases. Each patient then underwent cardiac catheterization, which demonstrated normal pulmonary artery pressure and diffuse pulmonary telangiectasis. Both patients were treated effectively with nifedipine and continue with this mode of therapy.     

Terbutaline versus nifedipine for prolongation of pregnancy in patients with preterm labor.

OBJECTIVE: To compare the effectiveness, safety, and possible adverse effects of terbutaline and nifedipine in prolonging pregnancy beyond 48 h. METHODS: A randomized controlled trial was conducted with 174 pregnant women admitted with preterm labor randomized into 2 groups, which were given terbutaline (95 patients) and nifedipine (79 patients), respectively. Bivariate and multivariate analyses, using logistic regression, were used to analyze the data. RESULTS: No statistically significant difference was found between the 2 groups in terms of prolongation of gestation to 48 h. The failure rate in terms of prolonging gestation for 24 h was found to be 12.6% for the terbutaline group and 10.1% for the nifedipine group, which was not found to be statistically significant (P value=0.61). Side effects were significantly more common in the terbutaline group, except for maternal hypotension. CONCLUSION: Terbutaline and nifedipine appear to be equally effective in their tocolytic action. However, nifedipine did have the advantage of ease of administration. It also had significantly less effect on the fetal heart rate.     

Anal fissure: the changing management of a surgical condition

Background Chronic anal fissure is a common benign disorder that causes severe, sharp anal pain during defaecation. Fissures are generally associated with raised resting anal pressures, and treatments are aimed at reduction of these pressures. Surgical sphincterotomy is very successful at healing fissures but is associated with significant morbidity. Much work has gone into the development of new pharmacological agents that can promote healing of chronic anal fissures by production of a reversible chemical sphincterotomy, with the aim of avoiding long-term problems of incontinence.Methods We review these recent innovations that have largely replaced surgery as first line treatment for chronic anal fissure.Conclusions Despite there being initial success with many of these pharmacological agents in the treatment of patients with chronic anal fissures, there are still some concerns about their use. In particular, the occurrence of side effects limits their use, and, unfortunately, they are not always effective at healing fissures. However, despite these drawbacks they remain excellent first-line options in the treatment of chronic anal fissures, and surgery should be offered only to patients who fail these therapies.     

Ventricular arrhythmia following short-acting nifedipine administration

Short-acting nifedipine is still advocated for use in children with severe hypertension, but is no longer recommended for use in adults because of adverse effects from rapid blood pressure reduction. A 19 year-old adolescent with symptomatic, severe hypertension (blood pressure 180/120) received 10 mg of short-acting nifedipine sublingually for blood pressure reduction. Within minutes after the dose, the patient complained of palpitations. Tachycardia (heart rate 100 beats per minute) and bigeminy were noted on the cardiac monitor. The bigeminy resolved but premature ventricular contractions were noted for the duration of her hospital stay. We hypothesize that reflex sympathetic activation following an abrupt drop in blood pressure may cause arrhythmias because of elevated catecholamine levels. Given this, it may be more appropriate to treat severe hypertension in children with intravenous antihypertensive agents that can be titrated to produce controlled reductions in blood pressure.     

Current medical therapy in the prevention and treatment of preterm labour

The prevention of preterm birth should be one of the major aims of antenatal care. Unfortunately, identification of women who will subsequently deliver preterm is imprecise. Prevention is also difficult. Surgical prevention with cerclage may help a proportion of women. Medical prevention is currently limited to the identification and treatment of bacterial vaginosis, although recent studies have suggested that progesterone prophylaxis may be helpful in some women. Confirmation of efficacy and safety is required before progesterone is introduced as long-term prophylaxis for all women at high risk. The optimal medical treatment (rather than prevention) of threatened preterm labour is controversial. Tocolysis is generally accepted to improve neonatal outcome although this has never been convincingly demonstrated in appropriate trials. Antibiotics confer benefit in the presence of ruptured membranes but are not indicated in uncomplicated preterm labour. In future, it may be possible to identify a subgroup of women in preterm labour with intact membranes who will benefit from tocolysis. The choice of first-line tocolytic therapy is currently debated but atosiban or nifedipine are suggested in current UK guidelines. A direct comparison of these drugs is required in a clinical trial. Although indirect comparisons have been made, these are difficult to interpret due to methodological differences. Each of these drugs have their advocates. Nifedipine has been reported to delay delivery and improve outcome but there are inconsistencies in the clinical trials. Atosiban is also reported to delay delivery and is well tolerated but improved neonatal outcome may have been hidden in clinical trials due to the requirement for rescue tocolysis.     

μ-Opioid receptor-induced Ca mobilization and astroglial development: morphine inhibits DNA synthesis and stimulates cellular hypertrophy through a Ca-dependent mechanism

Morphine, a preferential μ-opioid receptor agonist, alters astroglial development by inhibiting cell proliferation and by promoting cellular differentiation. Although morphine affects cellular differentiation through a Ca²⁺-dependent mechanism, few studies have examined whether Ca²⁺ mediates the effect of opioids on cell proliferation, or whether a particular Ca²⁺ signal transduction pathway mediates opioid actions. Moreover, it is uncertain whether one or more opioid receptor types mediates the developmental effects of opioids. To address these questions, the present study examined the role of μ-opioid receptors and Ca²⁺ mobilization in morphine-induced astrocyte development. Morphine (1 gmM) and non-morphine exposed cultures enriched in murine astrocytes were incubated in Ca²⁺-free media supplemented with < 0.005, 0.3, 1.0, or 3.0 mM Ca²⁺ ([Ca²⁺]_o), or in unmodified media containing Ca²⁺ ionophore (A23187), nifedipine (1 μM), dantrolene (10 μM), thapsigargin (100 nM), or l-glutamate (100 μM) for 0-72 h. μ-Opioid receptor expression was examined immunocytochemically using specific (MOR1) antibodies. Intracellular Ca²⁺ ([Ca²⁺]ⁱ) was measured by microfluorometric analysis using fura-2. Astrocyte morphology and bromodeoxyuridine (BrdU) incorporation (DNA synthesis) were assessed in glial fibrillary acidic protein (GFAP) immunoreactive astrocytes. The results showed that morphine inhibited astroglial growth by activating μ-opioid receptors. Astrocytes expressed MOR1 immunoreactivity and morphine's actions were mimicked by the selective μ, agonist PL017. In addition, morphine inhibited DNA synthesis by mobilizing [Ca²⁺]_i in developing astroglia. At normal [Ca²⁺]_o, morphine attenuated DNA synthesis by increasing [Ca²⁺]_i; low [Ca²⁺]_o (0.3 mM) blocked this effect, while treatment with Ca²⁺ ionophore or glutamate mimicked morphine's actions. At extremely low [Ca²⁺]_o (< 0.005 mM), morphine paradoxically increased BrdU incorporation. Although opioids can increase [Ca²⁺]_i in astrocytes through several pathways, not all affect DNA synthesis or cellular morphology. Nifedipine (which blocks L-type Ca²⁺ channels) did not prevent morphine-induced reductions in BrdU incorporation or cellular differentiation, while thapsigargin (which depletes IP₃-sensitive Ca²⁺ stores) severely affected inhibited DNA synthesis and cellular differentiation-irrespective of morphine treatment. However, dantrolene (an inhibitor of Ca²⁺-dependent Ca²⁺ release) selectively blocked the effects of morphine. Collectively, the findings suggest that opioids suppress astroglial DNA synthesis and promote cellular hypertrophy by inhibiting Ca²⁺-dependent Ca²⁺ release from dantrolene-sensitive intracellular stores. This implies a fundamental mechanism by which opioids affect central nervous system maturation.     

硝苯地平治疗早产的疗效观察

目的:观察硝苯地平对早产的治疗作用及不良反应。方法:将62例妊娠28~36周先兆早产的孕妇随机分为两组,分别口服硝苯地平和沙丁胺醇,观察两组用药后保胎效果、新生儿结局及不良反应。结果:口服硝苯地平后抑制宫缩显效时间为(38.54±11.54)m in,保胎成功率为83.33%,与沙丁胺醇组比较同样有效。主要不良反应为一过性血压降低、潮热、恶心、头痛等,占35.5%(11/31)。结论:硝苯地平治疗早产有效,且无明显不良反应。