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目的研究蒽环类联合紫杉类方案对三阴型乳腺癌进行新辅助化疗的疗效,应用动态增强磁共振成像(MRI)及组织病理学进行疗效评价。方法选择2008年1月至2011年12月北京大学第一医院乳腺疾病中心初始实施蒽环类联合紫杉类新辅助化疗并完成手术的三阴型乳腺癌病人为研究对象。疗效评价包括动态增强MRI临床评价及组织病理学评价。定义MRI评价包括临床完全缓解、临床部分缓解为临床评价有效,计算临床有效率;定义病理分级G3~G5为病理评价有效,计算病理有效率。结果共诊治1190例新发乳腺癌,其中三阴型乳腺癌129例(占10.8%),41例符合入组标准,新辅助治疗临床评价有效率为65.85%(27/41),病理评价有效率为85.37%(35/41),其中病理完全缓解率(pCR)为36.59%(15/41),新辅助治疗MRI评价与病理评价符合率为77.1%。结论蒽环类联合紫衫类方案是治疗三阴型乳腺癌的有效方法。动态增强MRI能准确评价三阴型乳腺癌新辅助化疗疗效,并与病理评价相符合。     

乳腺浸润性导管癌分子亚型与腋窝淋巴结转移的关系

目的:探讨乳腺浸润性导管癌不同分子亚型与其腋窝淋巴结转移的关系。方法:根据乳腺癌分子分型标准,将243例原发乳腺浸润性导管癌的手术患者分为Luminal A型、Luminal B型[又分为HER-2(-)和HER-2(+)]、HER-2过表达型和三阴型。结合临床病理资料,分析各分子亚型的分布特点,以及与腋窝淋巴结转移的关系。结果:243例患者中,Luminal B[HER-2(-)]型最多(78例,32.1%),其次是Luminal A型(58例,23.87%),随后为三阴型(41例,16.87%)、HER-2过表达型(34例,13.99%)、Luminal B[HER-2(+)]型(32例,13.17%);94例(38.68%)发生腋窝淋巴结转移,各分子亚型患者腋窝淋巴结转移发生率差异有统计学意义(P0.05),其中Luminal B[HER-2(-)]型(42例,53.85%)和Luminal B[HER-2(+)]型(15例,46.88%)中发生率最高,且两者间差异无统计学意义(P0.05),其后依次为Luminal A型(19例,32.76%),三阴型(12例,29.27%),HER-2过表达型(6例,17.65%);各分子亚型分布在累及1~3枚及≥4枚淋巴结转移的分组中,差异均无统计学意义(均P0.05),但前者Luminal B[HER-2(+)]型最多,HER-2过表达型最少,而后者HER-2过表达型最多,Luminal B[HER-2(+)]型最少。结论:乳腺浸润性导管癌的分子分型对评估腋窝淋巴结转移状况、判断疾病状态有一定参考价值,可成为制定个体化诊治策略的依据。     

乳腺癌分子亚型与MRI表现的相关性

目的探讨不同分子亚型乳腺癌与MRI表现的相关性。方法回顾性分析121例经手术病理证实的乳腺癌患者,根据雌激素受体(ER)、孕激素受体(PR)、人表皮生长因子受体(HER-2)表达状态,将乳腺癌分为HER-2过表达型、Luminal A型、Luminal B型和三阴性型,观察不同亚型乳腺癌MRI表现及其与分子亚型的相关性。结果 4种分子亚型乳腺癌T1WI多呈稍低信号[HER-2过表达型:68.00%(17/25),Luminal A型:66.67%(38/57),Luminal B型:76.19%(16/21),三阴性型55.56%(10/18)];HER-2过表达型多呈非肿块样强化[84.00%(21/25)],Luminal A型多呈不均匀强化[75.44%(43/57)],Luminal B型和三阴性型多呈环形强化[52.38%(11/21)、83.33%(15/18)];HER-2过表达型、Luminal B型和三阴性型时间-信号强度曲线多为廓清型[76.00%(19/25)、80.95%(17/21)和77.78%(14/18)],LuminalA型多为平台型[82.46%(47/57)];HER-2过表达型、Luminal B型和三阴性型多有伴随征象[80.00%(20/25)、76.19%(16/21)、66.67%(12/18)],Luminal A型49.12%(28/57)有伴随征象。乳腺癌增强MRI强化方式与分子亚型呈高度相关(C=0.737,P0.001),时间-信号强度曲线类型与分子亚型呈中度相关(C=0.567,P0.001)。结论乳腺癌分子亚型与MRI表现具有一定相关性,可通过MRI特征初步判断乳腺癌分子亚型。     

大连市不同型别乳腺癌患者的临床病理特征与生存状况研究

目的分析大连市不同型别乳腺癌妇女的临床病理特征与生存状况。方法选取2014年10月至2016年10月期间行外科手术的226例原发单侧乳腺癌患者为研究对象,根据分子分型分为Luminal A型、Luminal B型、HER-2型、三阴型,比较四种分型的临床病理资料和随访结果并比较之。采用SPSS19.0统计学软件进行数据处理。观测资料主要为计数资料,以例数及率描述,单因素分析采用χ^2检验。生存资料建立Kaplan-Meier乘积限模型,生存率比较应用Logrank检验。以P<0.05视为有统计学意义。结果LuminalA型、Luminal B型、HER-2型、三阴型分别占28.8%、34.1%、14.6%、22.6%。不同分子分型患者的肿瘤最大径、淋巴结转移、组织学分级、术后内分泌治疗等比较,差异有统计学意义(P<0.05)。四组不同分子分型患者的3年无病生存率、总生存率(OS)比较,经Logrank检验,仅Luminal A型的PFS生存率明显高于三阴型(P<0.05),其他差异无统计学意义(P>0.05)。结论大连市乳腺癌妇女患者以Luminal B型最常见,LuminalA型组织学分级较低,预后较好;HER-2型肿瘤较大,但淋巴结转移率较低;三阴型容易发生淋巴结转移,预后较差。内分泌治疗对Luminal型效果较好,靶向药物化疗适用于HER-2型和三阴型患者,放疗适用于晚期乳腺癌患者,尤其是三阴型。     

乳腺癌新辅助化疗疗效与分子分型的关系

目的探讨乳腺癌分子分型与表柔比星联合多西他赛（TE）方案新辅助化疗疗效的关系。方法根据纳入和排除标准,共纳入我院2011年5月至2012年12月期间至少接受过3周期TE方案治疗的乳腺癌患者共239例,其各项临床指标均完整。根据免疫组织化学雌激素受体（ER）、孕激素受体（PR）、人表皮生长因子受体2（HER-2）及Ki-67表达水平将患者分为4种亚型,分别为luminal A型、luminalB型、HER-2阳性型和三阴型。分析不同亚型乳腺癌患者的各项相关指标,如病理完全缓解（pCR）率、年龄、月经状态等。结果239例患者中,luminalA型67例（28．03％）,luminalB型84例（35．15％）,HER．2阳性型21例（8．79％）,三阴型67例（28．03％）。4型乳腺癌患者的年龄、月经状态、肿瘤大小、淋巴结状态等临床病理指标差异均无统计学意义（P〉0．05）。三阴型对TE方案的新辅助化疗的pCR率（14．93％）最高,其次依次为luminalB型（7．14％）、HER-2阳性型（4．76％）及luminalA型（1．49％）,差异有统计学意义（P=0．027）。结论三阴型相对luminalA型、luminalB型和HER-2阳性型对TE方案的新辅助化疗治疗更敏感,pCR率最高,治疗时需根据患者不同的分子亚型来选用特定的治疗方案。     

不同分子亚型双侧原发性乳腺癌临床分析

目的 探讨双侧原发性乳腺癌(bilateral primary breast cancer,BPBC)各分子亚型的临床病理特征及第一癌与第二癌分子亚型的一致性.方法 回顾性分析145例BPBC患者的临床病理资料,分析各分子亚型的临床病理特征,第一癌与第二癌间各分子亚型的一致性情况.结果 第一癌Luminal A型91例(62.8％),Luminal B型13例(9.0％),人表皮生长因子受体2(humanepidermal growth factor receptor 2,HER-2)型14例(9.7％),三阴性乳腺癌(triple negative breast cancer,TNBC)27例(18.6％);第二癌Luminal A型93例(64.1％),Luminal B型10例(6.9％),HER-2型14例(9.7％),TNBC 28例(19.3％).BPBC第一癌中,TNBC≤50岁及组织学Ⅲ级患者明显多于其他亚型(P＜0.05),各分子亚型在肿瘤大小、临床分期、淋巴结转移及病理类型上差异无统计学意义(均P＞0.05).第一癌与第二癌间Lumina A型和TNBC具有较好的一致性(K＞0.40),而Luminal B型和HER-2型的一致性较差(K＜0.40).两癌间隔时间短的BPBC分子亚型一致性较高.结论 BPBC各分子亚型的构成比及临床特征与单侧乳腺癌相似,LuminaA型、TNBC及两癌间隔时间短的BPBC其两侧分子亚型具有较好的一致性.     

雌激素受体β在不同分期及分型乳腺癌中的表达

目的 探讨雌激素受体β表达与不同分期及分型浸润性乳腺癌的关系. 方法 回顾性分析446例浸润性乳腺癌患者的临床病理资料,分析其与雌激素受体β的相关性.结果 在446例浸润性乳腺癌中,328例ERβ表达阳性(73.5％).在ERα+组及ERα-组,ERβ的阳性表达率分别为77.9％ (240/308)和63.8％ (88/138).ERβ的表达与ERα(P ＜0.01)表达呈正相关;与PR、组织学分级、HER-2及Ki-67表达无明确相关性(均P＞0.05).ERβ表达在不同年龄、肿瘤最大径及淋巴结转移组中的差异无统计学意义(均P ＞0.05).418例乳腺癌进入分期及NPI评分分析,不同分期及NPI评分在ERβ+及ERβ-两组之间分布差异无统计学意义(分期:P=0.743;NPI:P=0.644).Luminal A亚型、Luminal B1亚型、Luminal B2亚型、HER-2亚型及TN亚型中ERβ阳性率分别为75.6％ (88/118)、75.9％(110/145)、85.2％ (46/54)、68.4％(39/57)及62.5％(45/72).在不同分型乳腺癌中,Luminal型(LA、LB1及LB2)与非Luminal型(HER-2及TN)之间,ERβ的表达差异有统计学意义(P =0.007).结论 ERβ表达与肿瘤分期、NPI评分不相关,而与肿瘤Luminal分型相关.     

不同分子分型的乳腺癌患者个体化用药研究

探讨不同分子分型乳腺癌患者对个体化辅助化疗的反应,并评价其疗效。对2014年7月—2016年4月收治的90例患者进行化疗前穿刺活检,通过免疫组织化学和荧光原位杂交技术将患者按分子分型分为Luminal A型、Luminal B型、HER2(+)型和三阴性型。根据乳腺癌患者的分子分型制定相应的个体化辅助化疗方案,化疗结束后对患者行乳腺癌根治术,并对最终疗效进行评价。90例患者中,总的病理完全缓解(p CR)率为35.6%,部分缓解(PR)率为58.9%,病情稳定(SD)率为5.6%,无疾病进展(PD)发生。个体化用药的总体反应率(OR)为94.4%。采用相同治疗方案的Luminal B型和HER2(+)型患者最终疗效差异无统计学意义(P>0.05)。针对分子分型的不同对乳腺癌患者进行的个体化辅助化疗具有较好的疗效,其中恶性程度高的肿瘤患者在个体化治疗中获益更多。     

真空辅助下11G空芯针穿刺活检预测乳腺癌病理及分子亚型的准确性研究

目的 评估真空辅助下11G空芯针穿刺活检预测乳腺癌病理及分子业型的准确性.方法 回顾性分析广东省妇幼保健院2014年3月1日-2015年3月31日术前接受真空辅助11 G活检确诊为乳腺癌并随后行手术切除患者的临床资料.Kappa检验比较11 G空芯针穿刺标本与相应手术切除标本的病理类型、雌激素受体(ER)、孕激素受体(PR)、人表皮生长因子受体2(Her-2)、Ki-67、分子亚型的符合率.对免疫组化提示Her-2呈(++)的标本,则需荧光原位杂交(FISH)进一步明确状态.乳腺癌分子亚型分成Luminal A、Luminal B、Her-2过表达型及三阴型.结果 36例乳腺癌中(浸润性癌32例),穿刺标本与手术标本的病理类型、ER、PR、Her-2、Ki-67、分子亚型的符合率依次为94.4％(κ=0.934)、96.9％(κ=0.904)、87.5％(κ=0.710)、100％(κ=1.000)、84.4％(κ =0.570)、78.1％(κ=0.621).配对t检验显示两者间ER、PR、Ki-67表达值差异均无统计学意义(P＞0.05).两者间Her-2过表达型及Luminal B亚型符合率较好,分别为100％、94.1％.三阴型的符合率较差(33.3％),其次为Luminal A型(50％).如将ER/PR 的阳性标准从≥1％调整为≥10％,Ki-67的截断值调整为≥20％.ER、PR、Ki-67、分子亚型的符合率可高达100％、93.8％、87.5％、81.3％.结论 术前真空辅助11G空芯针穿刺活检可准确预测乳腺癌病理类型及分子亚型.     

腋窝前哨淋巴结转移与T_1、T_2期乳腺癌分子分型的相关分析

目的探究腋窝前哨淋巴结转移与T_1、T_2期乳腺癌分子分型的相关关系。方法从本院2016年1月至2018年12月选取285例浸润性乳腺癌并进行手术治疗的患者,观察比较四个分子分型,三阴型、Her-2过表达型、Luminal A型、Luminal B型之间,腋窝前哨淋巴结的转移情况。结果 T_1、T_2期两组乳腺癌中,三阴型、Her-2过表达型、Luminal A型、Luminal B型的腋窝前哨淋巴结转移率存在明显差异,有统计学意义(P0.05)。其中Luminal B型的淋巴结转移率比较高,T_1组中为16.18%,T_2组中为37.5%。结论腋窝前哨淋巴结转移与T_1、T_2期乳腺癌分子分型存在相关性,发生腋窝前哨淋巴结转移的概率Luminal B型比较高,三阴型发生概率相对较低。     

Histochemical and contractile properties of striated muscles of urethra and levator ani of dogs and sheep

AIMS: To understand their possible importance in long- and short-term control of continence, some properties of the striated muscles of the urethra and pelvic floor (levator ani) of dogs and sheep were investigated, especially fiber types and contractile characteristics. MATERIALS AND METHODS: Striated muscles of urethra and levator ani of 29 male and 6 female dogs and 11 male and 6 female sheep were removed and cut into strips. Some strips were frozen and stained for ATPase at pH 9.4 and 4.3 for fiber typing; others were set up in an organ bath to study contractile responses to nerve stimulation. RESULTS: All muscles contained both type I (slow) and type II fibers, ranging from 97% type II in female greyhound urethra to 60% in female sheep levator ani. For each muscle, there were fewer type II muscles in sheep than in dog. The diameters of the urethral fibers were about 60% of the levator ani in dogs and 34% in sheep. Contraction of the urethral muscle was faster than for levator ani and declined to about 80% of the peak, 500 msec after the beginning of stimulation at 20 Hz. The levator ani contraction rose to a steady level as long as stimulation continued. CONCLUSIONS: Both the levator ani and urethral striated muscles contain slow and fast fiber types. The levator ani muscles are capable of sustained contraction with rapid onset which will produce long-term closure of the urethra. The circular urethral muscle contraction was faster but less well maintained.     

Incorporation and release of85Sr and14C-proline-hydroxyproline in mineral and collagen of bone and incisor teeth of growing rats

The extent to which exchange and reutilization processes of mineral tracers affect skeletal mineral accretion and resorption measurements was evaluated by comparing the rates of appearance and disappearance of⁸⁵Sr and¹⁴C-proline-hydroxyproline in bones and teeth in growing rats for 12 days following simultaneous parenteral injection of these tracers. Expressions for the relative rates of collagen synthesis and breakdown, which unlike mineral metabolism are considered not to be complicated by exchange phenomena, were based on¹⁴C-proline conversion to¹⁴C-hydroxyproline; the specific activity of the latter was determined. Both the mineral and the collagen specific activities reflected the rates and patterns of growth of the samples assayed; rapid growth and a short interval of time between formation and resorption of tissue in themetaphyseal bone which contains the cartilagineous growth plate, slow growth and an interval of time between formation and resorption of tissue indiaphyseal bone and incisor teeth which is longer than the 12 days of the experiment. However, in metaphyseal bone the specific activity collagen/mineral ratio dropped by one half during the 4–12 day interval in contrast to diaphyseal bone and incisor teeth in which no change in this ratio was observed during this period of time. The data indicate that collagen in the metaphyseal growth zone is removed by resorption before it has become fully mineralized, and that exchange is a relatively unimportant factor in the long term kinetics of bone mineral.

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Zusammenfassung Das Ausmaß, bis zu welchem Austausch- und Wiederverwendungsprozesse der mineralen Tracer die Messungen des mineralen Skelett-Auf- und Abbaues beeinflussen können, wurde ausgewertet; zu diesem Zweck wurde die Geschwindigkeit des Auftretens und Verschwindens von⁸⁵Sr und von¹⁴C-Prolin-Hydroxyprolin in Knochen und Zähnen von wachsenden Ratten während der 12 auf die simultane parenterale Injektion dieser Tracer folgenden Tage verglichen.Der Ausdruck für die relative Geschwindigkeit des Kollagen-Auf- und Abbaues, bei welchem im Gegensatz zum Mineralmetabolismus kein Mitwirken des Austauschphänomens vermutet wird, basiert auf der Umwandlung von¹⁴C-Prolin zu¹⁴C-Hydroxyprolin; die spezifische Aktivität des letzteren wurde bestimmt.Aus der spezifischen Aktivität des Minerals sowie jener des Kollagens konnten die Geschwindigkeit und die Art des Wachstums der untersuchten Proben ersehen werden, d.h.schnelles Wachstum und ein kurzes Zeitintervall zwischen Bildung und Resorption des Gewebes imKnochen der Metaphyse, die auch die knorpelige Wachstumsplatte enthält, und andererseitslangsames Wachstum und längeres Zeitintervall (länger als die 12 Tage des Experimentes) zwischen Bildung und Resorption des Gewebes imKnochen der Diaphyse und in den Schneidezähnen. Immerhin fiel die spezifische Aktivität des Kollagen/Mineral-Anteils im Knochen der Metaphyse während dem 4–12tägigen Zeitintervall auf die Hälfte, im Gegensatz zum Knochen der Diaphyse und der Schneidezähne, bei welchen während dieser Zeitspanne kein Unterschied in diesem Verhältnis beobachtet wurde.Diese Ergebnisse zeigen, daß Kollagen in der Wachstumszone der Metaphyse durch Resorption verschwindet, bevor es ganz mineralisiert ist, und daß der Austausch ein relativ unwichtiger Faktor in der Kinetik auf lange Sicht des Knochenminerals ist.

     

Instrumented ligamentotaxis and stabilization of compression and burst fractures of dorsolumbar and mid-lumbar spines

Background:

Controversy continues regarding the best treatment for compression and burst fractures. The axial distraction reduction utilizing the technique employing the long straight rod or curved short rod without derotation to reduce fracture are practised together with short segment posterolateral fusion (PLF). Effects of the early postoperative mobilization without posterolateral fusion on reduction maintenance and fracture consolidation were not evaluated so far. The present prospective study is designed to assess the effectiveness of i) reduction and restoration of sagittal alignment, ii) no posterolateral fusion on the reduced, fractured vertebral body and injured disc, iii) fracture consolidation and iv) the fate of the unfused cephalad and caudal injured motion segments of the fractured vertebra.

Materials and Methods:

The study includes 15 Denis burst and two Denis type D compression fractures between T₁₂ and L₃. The lordotic distraction technique was used for ligamentotaxis utilizing the contoured short rods and pedicle screw fixator. Three vertebrae including the fractured one were fixed. The patients after surgery were braced for ten weeks with activity restriction for 2-4 weeks. The patients were evaluated for change in vertebral body height, sagittal curve, reduction of retropulsion, improvement in neural deficit. The unfused motion segments, residual postoperative pain and bone and metal failure were also evaluated.

Results:

The preoperative and postreduction percentile vertebral heights at, zero (immediate postoperative), at three, six and 12 months followup were 62.4, 94.8, 94.6, 94.5 and 94.5%, respectively. The percentages of the intracanal fragment retropulsion at preoperative, and postoperative at zero, 3, 6 and 12 months followup were 59.0, 36.2,, 36.0, 32.3, and 13.6% respectively.The preoperative and postreduction percentile loss of the canal dimension and at zero, three, six and 12 months were 52.1, 45.0, 44.0, 41.0 and 29% respectively suggesting that the under-reduced fragment was being resorbed gradually by a remodeling process. The mean initial kyphosis of 33° became mean 2° immediately after reduction and mean 3° at the final followup. The fractured vertebral bodies consolidated in an average period of ten weeks (range 8-14 weeks). The restored disc heights were relatively well maintained throughout the observation period. All paraparetic patients recovered neurologically. There were no postoperative complications.

Conclusion:

Instrument-aided ligamentotaxis for compression and burst fractures utilizing the short contoured rod derotation technique and the instrumented stabilization of the fractured spine are found to be effective procedures which contribute to the fractured vertebral body consolidation without recollapse and maintain the motion segment function.     

Principles and Practice of Hemofiltration and Hemodiafiltration

There is growing interest in the convective dialysis therapies, hemofiltration (HF) and hemodiafiltration (HDF). Both require dialysis membranes which are highly permeable to solutes as well as fluid, and in both cases large volumes of ultrafiltration are the condition for convective transport. In HDF the convection is combined with diffusion, and as a consequence, maximum clearance over the entire molecular weight spectrum is achieved. Optimal forms of HDF provide urea clearance 10–15% higher than the corresponding diffusive mode. The larger the solute, the greater is the impact of convection, and β₂-microglobulin (β₂m) levels may be up to 70% reduced. Traditional postdilution HF provides high clearance of medium sized and large molecules. Satisfactory clearance of small solutes requires blood flows in excess of 500 ml/min. With access to practically unlimited volumes of substitution solution through on-line ultrafiltration, predilution HF can now be used. This increases the clearance of small solutes to an acceptable range. For HDF as well as HF, large patient populations consistently treated for longer periods of time are needed to make valid outcome comparisons with other therapies.     

Recognition and management of phaeochromocytoma and paraganglioma

Phaeochromocytomas and paragangliomas (PPGL) are catecholamine-secreting neuroendocrine tumours arising from the chromaffin cells in the adrenal medulla. These tumours may be identified incidentally, as part of a work-up for multiple endocrine neoplasia or following haemodynamic surges during unrelated procedures. Advances in perioperative management and improved management of intraoperative haemodynamic instability have significantly reduced surgical mortality from around 40% to less than 3%. Surgery is the definitive treatment in most cases and laparoscopic resection where possible is associated with improved outcomes. Anaesthetic management of PPGL cases represents a unique haemodynamic challenge both before and after tumour resection. In this article we describe the physiology of these tumours, their diagnosis, preoperative optimization methods, intraoperative anaesthetic management and management of postoperative complications.     

骨折不愈合与延迟愈合的成因与治疗

目的探讨骨折不愈合与延迟愈合的成因、报肯治疗的方法与设果。方法对1990年7月～2004年12月间收治的107例骨折不愈台、54例骨折延迟愈合2例先天性胫骨骨不连进行回顾性研究，分析原因，随访治疗结果。18例延迟愈合行保守治疗，本组其他145例行手术治疗，结果除2例先天性胫骨骨不连外，其余161例的成因中均有医源性因素。10例失去随访，153例平均随访17（6-28）个月，骨折均获骨性连接，愈合时间平均10（6-14）个月，肢体功能恢复良好，结论医源性技术缺陷是骨折不愈合与延迟愈合的主要原因，针对各种不同因素进行合理治疗可获得满意效果。     

Physiology and pharmacology of nausea and vomiting

Nausea and vomiting are both very unpleasant experiences. The physiology is poorly understood; however, understanding what we do know is key to tailoring a preventative or therapeutic antiemetic regime. There are two key sites in the central nervous system implicated in the organization of the vomiting reflex: the vomiting centre and the chemoreceptor trigger zone. There are five key neurotransmitters involved in afferent feedback to these areas. These are histamine (H₁ receptors), dopamine (D₂), serotonin (5-HT₃), acetyl choline (muscarinic) and neurokinin (substance P). Postoperative nausea and vomiting will occur in around one-third of elective patients who have no prophylaxis. This can result in many detrimental effects including patient dissatisfaction, unplanned admission and prolonged recovery. It is therefore essential that clinicians understand how they can prevent and treat nausea and vomiting using either a single agent or a combination of antiemetics to target relevant receptors. Commonly used drugs include antihistamines, dopamine antagonists, serotonin antagonists and steroids. More novel agents are being developed such as aprepitant, a neurokinin receptor antagonist, palonosetron, a 5HT₃ receptor antagonist and nabilone, a synthetic cannabinoid.     

Physiology and pharmacology of nausea and vomiting

Nausea and vomiting are both very unpleasant experiences. The physiology is poorly understood; however, understanding what we do know is key to tailoring a preventative or therapeutic antiemetic regime. There are two key sites in the central nervous system implicated in the organization of the vomiting reflex: the vomiting centre and the chemoreceptor trigger zone. There are five key neurotransmitters involved in afferent feedback to these areas. These are histamine (H₁ receptors), dopamine (D₂), serotonin (5-HT₃), acetyl choline (muscarinic) and neurokinin (substance P). Postoperative nausea and vomiting will occur in around one-third of elective patients who have no prophylaxis. This can result in many detrimental effects including patient dissatisfaction, unplanned admission and prolonged recovery. It is therefore essential that clinicians understand how they can prevent and treat nausea and vomiting using either a single agent or a combination of antiemetics to target relevant receptors. Commonly used drugs include antihistamines, dopamine antagonists, serotonin antagonists and steroids. More novel agents are being developed such as aprepitant, a neurokinin receptor antagonist, palonosetron, a 5HT₃ receptor antagonist, and nabilone, a synthetic cannabinoid.