宫颈鳞状细胞癌和癌前病变中Skp2表达及其与HPV16/18感染的关系

目的 探讨skp2在宫颈鳞状细胞癌和癌前病变中的表达规律及其与人乳头状瘤病毒(HPV)感染之间的关系.方法 采用免疫组织化学(ABC法)和原位杂交检测Skp2蛋白和HPV16/18 DNA在30例正常宫颈鳞状上皮、29例宫颈低级别上皮内瘤变、31例高级别上皮内瘤变和31例宫颈鳞状细胞癌中的表达.结果 Skp2在正常宫颈鳞状上皮中呈阴性,与宫颈低级别上皮内瘤变(阳性表达率为13.8%,4/29)之间差异无统计学意义(P>0.05).随着上皮病变级别升高,表达也逐渐增强,在宫颈鳞状细胞癌中表达更强;HPV16/18 DNA在四组中的阳性表达率,除高级别上皮内瘤变和宫颈鳞状细胞癌两组间差异无统计学意义外(均为96.8%),其余各组之间差异均有统计学意义(P<0.01);在宫颈低级别上皮内瘤变中skp2蛋白表达和HPV感染相关无统计学意义,但在高级别上皮内瘤变和宫颈鳞状细胞癌两组中均呈正相关(γ高级别=0.373,γ癌 =0.416,P<0.05).结论 Skp2过表达主要在宫颈鳞状细胞癌形成的中晚期起作用,可作为一个早期诊断恶性的指标,且可能与HPV16/18感染有协同作用.E7-skp2-Rb可能是HPV感染诱导宫颈鳞状细胞癌形成的一条新致癌途径.     

人乳头状瘤病毒阴性的宫颈癌及其癌前病变中p16INK4A蛋白表达和DNA倍体分析

目的探讨人乳头状瘤病毒（HPV）感染阴性的宫颈癌及其癌前病变中p16^INK4A蛋白表达和DNA倍体分析的临床病理学意义。方法应用PCR方法筛查出HPV感染阴性的20例慢性宫颈炎、20例宫颈上皮内瘤变（CIN）、3例宫颈腺上皮内瘤变（CGIN）、38例浸润性鳞状细胞癌（鳞癌）和15例浸润性腺癌作为研究对象。应用免疫组织化学（LSAB）染色方法检测p16^INK4A蛋白在这些病变组织中的表达,并结合流式细胞仪DNA倍体分析探讨HPV阴性的宫颈癌的早期诊断和预后判定。结果p16^INK4A蛋白特异性地表达在CIN和CGIN病变、鳞癌以及腺癌细胞的胞核和胞质中,而在正常鳞状上皮和腺上皮中没有任何阳性表达信号。另外,DNA异倍体在浸润性鳞癌和腺癌中的表达率明显高于CIN病变组（P〈0．01）。在有淋巴结转移的浸润癌中DNA异倍体存在的百分率高于无淋巴结转移组,但尚未发现差异有统计学意义。在8例p16^INK4A表达阴性的浸润性鳞癌中有2例表现为DNA异倍体。结论p16^INK4A蛋白检测可以作为HPV感染阴性的宫颈鳞癌及腺癌的早期诊断指标,结合DNA倍体分析将对宫颈恶性肿瘤的诊断有重要的辅助意义。     

宫颈上皮内瘤变中p16INK4A和Ki-67的表达

摘要：目的探讨p16^INK4A、Ki-67和HPV抗原表达及高危型HPV（HR—HPV）检测在宫颈上皮内瘤变（CIN）病理诊断中的意义。方法选取宫颈活检病理确诊为CIN的组织蜡块101例,重新切片,应用免疫组化两步法检测p16^INK4A、Ki-67和HPV抗原表达,并取正常宫颈组织50例进行对比研究。同时,应用第二代杂交捕获法对其中25例CIN组织样品进行HR—HPV检测。结果p16^INK4A蛋白表达水平在CINI、CINⅡ、CINⅢ级之间差异有非常显著性（P〈0．001）,其表达水平随着CIN级别的增高而增加,呈现良好的线性相关性（P〈0．001）;Ki-67蛋白表达阳性细胞多少与CIN分级之间无显著相关性（P〉0．05）,但其在宫颈鳞状上皮中的位置分布与CIN级别之间却有显著相关性（P〈0．05）;HPV抗原免疫组化染色阳性反应仅呈现于CIN鳞状上皮表层挖空细胞内,其阳性率在不同级别CIN之间的差异无统计学意义（P〉0．05）;HR—HPV在CINI、CINⅡ和CINⅢ级的检出率分别为81．8％、80．0％和100．0％,但其检出率在不同级别CIN之间差异也无显著性（P〉0．05）。结论p16^INK4A和Ki-67染色对CIN的病理诊断和分级具有一定诊断价值,对于CINI级形态结构不典型的病例,HR—HPV的检测结果对病理诊断有辅助意义。     

应用基因芯片诊断宫颈石蜡组织样本中人乳头状瘤病毒感染及其临床意义

目的探讨应用基因芯片检测宫颈石蜡组织标本中人乳头状瘤病毒（HPV）感染的可能性及其临床意义。方法收集解放军总医院诊断为宫颈鳞状上皮病变的石蜡组织标本40例,其中宫颈浸润性鳞癌18例,宫颈上皮内瘤变（CIN）Ⅲ12例,CINⅠ4例,CINⅡ6例。从组织中提取DNA后采用基因芯片检测23种常见HPV基因亚型,即PCR扩增后产物在基因芯片上进行杂交。同时选用10例经基因芯片检测16型和18型基因阳性的宫颈鳞癌的石蜡组织切片做原位杂交。基因芯片检测结果与部分原位杂交结果进行比较并分析。结果基因芯片检测的18例宫颈鳞癌HPV高危亚型均为阳性（100％）,其中1例为混合阳性;12例CINⅢ中11例为高危亚型阳性（91．7％）,1例阴性;6例CINⅡ的宫颈病变中高危型5例阳性,低危型1例阳性;4例CINⅠ中有2例低危型阳性、2例阴性;宫颈鳞癌和CINⅢ组与CINⅠ和Ⅱ组比较,差异有统计学意义（U=80．0,P〈0．01）。10例宫颈鳞癌基因芯片HPV16型和18型阳性组织中,原位杂交同型探针6例检测显示阳性。结论HPV基因芯片技术可用于检测多种亚型,特异性强,敏感性高,对HPV感染亚型的鉴别及宫颈癌的预防和治疗具有重要意义。     

p16INK4a在宫颈细胞学鳞状上皮内瘤变中的意义

目的探讨p16^INK4a的表达在宫颈细胞学中鳞状上皮内瘤变中的意义及其与人乳头状瘤病毒（HPV）型别之间的关系。方法对88例经活检证实的液基细胞学标本[包括20例慢性宫颈炎、18例低度鳞状上皮内瘤变（LSIL）、34例高度鳞状上皮内瘤变（HSIL）及16例鳞状上皮细胞癌（SCC）],分别用免疫细胞化学（EnVision方法）检测其p16^INK4a的表达,并对所有标本用聚合酶链反应（PCR）方法检测HPV型别（包括HPV16、18、31、33、35、39、45、51、52、53、56、58、59、66、68、6、11、42、43及44型）。结果p16^INK4a在慢性宫颈炎组呈阴性,在LSIL、HSIL及SCC组的表达率分别为27．8％、100％及100％,LSIL、HSIL及SCC组p16^INK4a的表达均显著高于慢性宫颈炎组（P〈0．01）;p16^INK4a在高危型HPV感染组的表达率（96．4％）显著高于低危型HPV感染组（7．7％）,差异有统计学意义（t=4．32,P〈0．01）。结论p16^INK4a是一种敏感性较高,特异性较好的标记物,可以识别与高危型HPV有关的非典型鳞状上皮细胞。     

宫颈癌及其前期病变HPV感染与基因型分布

目的了解宫颈癌及宫颈上皮内瘤变CIN患者的HPV的感染和其基因分型及主要感染型别情况。方法应用型特异PCR检测宫颈癌及其前病变的患者的HPV感染及其主要基因分型情况的分析。结果在本研究宫颈癌及宫颈上皮内瘤变患者中,宫颈癌的HPV感染率为91．0％,CINⅠ／Ⅱ／Ⅲ的HPV感染率为73．3％,主要高危型HPV基因型别依次为HPV16、HPV18、HPV58、HPV33。结论在宫颈上皮内瘤变患者中感染主要高危型HPV基因型别依次为HPV16、HPV18、HPV58、HPV33、HPV16在宫颈癌和CIN中的构成比随着宫颈病变的增加而明显增加。     

原位核酸分子杂交技术检测宫颈鳞状上皮病变HPV感染

目的:观察宫颈鳞状上皮病变过程中HPV6/11、HPV16/18的表达,探讨其测定的临床意义.方法:选择病理诊断为宫颈慢性炎症50例、鳞状上皮乳头状瘤样增生30例、尖锐湿疣30例、上皮内瘤变89例、鳞癌50例共249例石蜡包埋标本,应用原位核酸分子杂交技术对其进行HPV6/11,HPV16/18检测.结果:慢性炎症组HPV6/11阳性表达4%,HPV16/18阳性表达0%;乳头状瘤样增生组HPV6/11阳性表达10%,HPV16/18阳性表达3.3%;尖锐湿疣组HPV6/11阳性表达93.3%,HPV16/18阳性表达23.3%;CIN组中Ⅰ级HPV6/11阳性表达48.9%,HPV16/18阳性表达42.2%;Ⅱ级HPV6/11阳性表达39.1%,HPV16/18阳性表达69.6%;Ⅲ级HPV6/11阳性表达9.5%,HPV16/18阳性表达66.7%;鳞癌组HPV6/11阳性表达6%,HPV16/18阳性表达82%.结论:应用原位核酸分子杂交技术检测宫颈鳞状上皮病变细胞的HPV6/11、HFV16/18,为临床早期诊断、鉴别诊断及评估预后提供可靠的理论依据.     

宫颈癌组织APOBEC3A蛋白的表达与高危型HPV感染的相关性研究

 目的： 探讨宫颈癌组织中载脂蛋白 B mRNA 编辑酶催化多肽样蛋白3A（APOBEC3A）表达与高危型人乳头瘤病毒（HPV）感染的关系。方法： 采用免疫组化法检测26例宫颈癌、27例宫颈上皮内瘤变（CIN）I～III和22例正常宫颈组织APOBEC3A蛋白的表达,同时使用凯普分型检测试剂盒对3组样品分别进行高危HPV16/HPV18分型检测。以脂质体法转染APOBEC3A质粒进入HeLa细胞,RT-qPCR与Western blotting验证APOBEC3A对高危型HPV18 E6 mRNA以及蛋白表达的影响。结果：宫颈癌组织、CIN组织以及正常宫颈组织中APOBEC3A蛋白表达的阳性率分别为46.2%、92.6%和86.4%,宫颈癌组织中APOBEC3A蛋白表达较正常宫颈组织明显下降（P<0.01）。宫颈癌组织、CIN及正常宫颈组织中HPV16感染阳性率分别为92.3%、77.8%和54.5%; HPV18感染阳性率分别为80.8%、51.8%和68.2%;APOBEC3A蛋白表达与HPV18感染阳性率呈负相关(P<0.05)。增加HeLa细胞中APOBEC3A的表达明显降低了HPV18 E6 mRNA以及蛋白的表达。结论：在宫颈癌组织中APOBEC3A高表达可以对抗HPV18感染,并抑制HPV18 E6的转录和表达。     

子宫颈鳞状上皮内瘤变及鳞状细胞癌中间质细胞CD34、α-SMA的表达及意义

目的探讨CD34和平滑肌肌动蛋白（α-SMA）在宫颈各种病变间质细胞中的表达及其在宫颈癌早期浸润诊断中的价值。方法应用免疫组化SP法检测78例宫颈各种病变组织（正常10例、低级别CIN15例、高级别CIN16例、宫颈癌伴早期浸润15例、宫颈癌22例）的间质细胞中CD34、α-SMA的表达。结果CD34在所有正常宫颈和低级别CIN间质细胞中均表达,高级别CIN阳性表达率为87．5％（14／16）,而在宫颈癌伴早期浸润和宫颈癌中阳性表达率分别为40％（6／15）和40．9％（9／22）,宫颈癌伴早期浸润和癌组织明显低于正常、低级别和高级别CIN（P〈0．05）。α-SMA在正常宫颈间质细胞中无表达,低级别和高级别CIN阳性表达率分别为13．3％（2／15）和81．3％（13／16）,而所有宫颈癌伴早期浸润和宫颈癌间质细胞中均有α-SMA的表达,高级别CIN、宫颈癌伴早期浸润和宫颈癌高于低级别CIN（P〈0．05）。结论宫颈间质细胞。CD34表达缺失和α-SMA表达获得与宫颈鳞状上皮的恶性转化密切相关。检测宫颈病变中间质细胞CD34和α-SMA的表达有助于在小的活检标本中宫颈早期浸润癌和宫颈癌的诊断。     

脱落细胞人乳头瘤病毒L1壳蛋白的半定量检测有助于宫颈病变的鉴别诊断

目的研究人乳头瘤病毒L1(HPV L1)壳蛋白的表达量与宫颈上皮内瘤变的关系及其临床意义。方法采用免疫细胞化学方法检测153例宫颈脱落细胞中HPV L1壳蛋白的表达,用ImagePro Plus图像分析软件对HPV L1壳蛋白阳性单位(PU)进行半定量检测,并以宫颈活检的组织病理学结果为确诊标准。结果 HPV L1壳蛋白PU在宫颈细胞学分类为正常/炎症、未知意义的不典型鳞状细胞(ASCUS)、低级别上皮内瘤变、高级别上皮内瘤变组别中定量结果依次为46.87±24.46、27.23±24.30、24.10±22.45、9.36±19.82,差异具有统计学意义(P0.01);其PU在组织学正常/炎症、低级别上皮内瘤变、高级别上皮内瘤变分组中分别为41.30±26.66、24.84±22.18、8.69±19.20,差异具有统计学意义(P0.01);HPV L1壳蛋白PU与宫颈疾病的严重程度在细胞学分组和组织学分组中均呈负相关(r=-0.458,r=-0.441,P0.01)。在高危型HPV感染的细胞中,HPV L1壳蛋白PU在HPV16、HPV18中的含量低于其他分型,差异具有统计学意义(P0.01),HPV L1壳蛋白PU与年龄无关(P0.05)。结论半定量分析HPV L1壳蛋白在诊断宫颈癌前病变中具有一定的指导作用。     

Opportunities and challenges in the prevention and control of cancer and other chronic diseases: children's diet and nutrition and weight and physical activity

OBJECTIVE: The purpose of this article is to review the role of behavioral research in disease prevention and control, with a particular emphasis on lifestyle- and behavior-related cancer and chronic disease risk factors--specifically, relationships among diet and nutrition and weight and physical activity with adult cancer, and tracking developmental origins of these health-promoting and health-compromising behaviors from childhood into adulthood. METHOD: After reviewing the background of the field of cancer prevention and control and establishing plausibility for the role of child health behavior in adult cancer risk, studies selected from the pediatric published literature are reviewed. Articles were retrieved, selected, and summarized to illustrate that results from separate but related fields of study are combinable to yield insights into the prevention and control of cancer and other chronic diseases in adulthood through the conduct of nonintervention and intervention research with children in clinical, public health, and other contexts. RESULTS: As illustrated by the evidence presented in this review, there are numerous reasons (biological, psychological, and social), opportunities (school and community, health care, and family settings), and approaches (nonintervention and intervention) to understand and impact behavior change in children's diet and nutrition and weight and physical activity. CONCLUSIONS: Further development and evaluation of behavioral science intervention protocols conducted with children are necessary to understand the efficacy of these approaches and their public health impact on proximal and distal cancer, cancer-related, and chronic disease outcomes before diffusion. It is clear that more attention should be paid to early life and early developmental phases in cancer prevention.     

Pain and Effusion and Quadriceps Activation and Strength

Context:

Quadriceps dysfunction is a common consequence of knee joint injury and disease, yet its causes remain elusive.

Objective:

To determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion affect the magnitude of quadriceps dysfunction.

Design:

Crossover study.

Setting:

University research laboratory.

Patients or Other Participants:

Fourteen (8 men, 6 women; age = 23.6 ± 4.8 years, height = 170.3 ± 9.16 cm, mass = 72.9 ± 11.84 kg) healthy volunteers.

Intervention(s):

All participants were tested under 4 randomized conditions: normal knee, effused knee, painful knee, and effused and painful knee.

Main Outcome Measure(s):

Quadriceps strength (Nm/kg) and activation (central activation ratio) were assessed after each condition was induced.

Results:

Quadriceps strength and activation were highest under the normal knee condition and differed from the 3 experimental knee conditions (P < .05). No differences were noted among the 3 experimental knee conditions for either variable (P > .05).

Conclusions:

Both pain and effusion led to quadriceps dysfunction, but the interaction of the 2 stimuli did not increase the magnitude of the strength or activation deficits. Therefore, pain and effusion can be considered equally potent in eliciting quadriceps inhibition. Given that pain and effusion accompany numerous knee conditions, the prevalence of quadriceps dysfunction is likely high.Key Words: arthrogenic muscle inhibition, central activation failure, voluntary activation, muscles

Key Points

• Knee pain and effusion resulted in arthrogenic muscle inhibition and weakness of the quadriceps.
• The simultaneous presence of pain and effusion did not increase the magnitude of quadriceps dysfunction.
• To reduce arthrogenic muscle inhibition and improve muscle strength, clinicians should employ interventions that target removing both pain and effusion.

Quadriceps weakness is a common consequence of traumatic knee joint injury^1,2 and chronic degenerative knee joint conditions.^3,4 Arthrogenic muscle inhibition (AMI), a neurologic decline in muscle activation, results in quadriceps weakness and hinders rehabilitation by preventing gains in strength.⁵ The inability to reverse AMI and restore muscle function can lead to decreased physical abilities,⁶ biomechanical deficits,⁷ and possibly reinjury.⁵ Furthermore, researchers^8,9 have suggested that quadriceps weakness resulting from AMI may place patients at risk for developing osteoarthritis in the knee. In light of the substantial influence of quadriceps AMI on these clinically relevant outcomes, we need to improve our understanding of the factors that contribute to this neurologic decline in muscle activity so efforts to target and reverse it can be implemented and gains in strength can be achieved more easily.Joint injury and disease are accompanied by numerous sequelae (ie, pain, swelling, tissue damage, inflammation), so ascertaining which one ultimately leads to neurologic muscle dysfunction is difficult. Whereas a joint effusion can result in AMI,^10–12 the effects of pain are less understood despite many clinicians attributing AMI to pain. Using techniques that introduce knee pain without accompanying injury may provide insights into the role of pain in eliciting AMI.The degree of knee joint damage may play a role in the quantity of AMI that manifests. Hurley et al^13,14 demonstrated that quadriceps AMI, measured using an interpolated-twitch technique, was greater in patients with extensive traumatic knee injury (eg, fractured tibial plateau, ruptured medial collateral ligament, and medial meniscectomy) than patients with isolated joint trauma (ie, isolated anterior cruciate ligament [ACL] rupture). Similarly, patients with more knee joint symptoms (ie, greater number of symptoms and increased severity of symptoms) may present with greater magnitudes of quadriceps inhibition. Recently, investigators¹⁵ have suggested that patients with more pain display less quadriceps strength, supporting this tenet. Given that effusion and pain often present simultaneously with joint injuries and diseases, such as ACL injury and osteoarthritis, examining both the isolated and cumulative effects of these sequelae appears warranted to determine if they influence the magnitude of muscle inhibition.Experimental joint-effusion and pain models are safe and effective experimental methods that allow for the isolated examination of their effects on muscle function. The effusion model, whereby sterile saline is injected directly into the knee joint capsule,⁷ produces a clinically relevant magnitude of the joint effusion that may be present with traumatic injury. Effusion is thought to activate group II afferents responding to stretch or pressure,^16–18 which in turn may facilitate group Ib interneurons and result in quadriceps AMI.⁵ The pain model involves injecting hypertonic saline into the infrapatellar fat pad to produce anteromedial knee pain similar to that described in patients with patellofemoral pain syndrome.¹⁹ Pain is considered to initiate AMI through activation of group III and IV afferents that act as nocioceptors to signal damage or potential damage to joint structures.^16–18 The firing of these afferents then may lead to facilitation of group Ib interneurons, the flexion reflex, or the gamma loop, ultimately resulting in quadriceps inhibition.²⁰ Thus, these models allow us to create symptoms that are associated with knee injury and have the added benefit of providing a way to examine their effects in isolation.Therefore, the purpose of our study was to determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion would affect the magnitude of quadriceps dysfunction. We hypothesized that pain alone would result in quadriceps inhibition and that the magnitude of inhibition would be greater when effusion and pain were present simultaneously.     

Postinfectious immunodeficiency and autoimmunity: pathogenic and clinical values and implications

Autoimmunity is still a mystery of clinical immunology and medicine as a whole. The etiology and pathogenesis of autoimmune disorders remain unclear and, thus, are assessed as a balance between hereditary predisposition, triggering factors and the appearance of autoantibodies and/or self-reactive T cells. Among the immunological armamentarium, molecular mimicry, based on self-reactive T- and B-cell activation by cross-reactive epitopes of infectious agents, is of special value. Hypotheses regarding the possible involvement of molecular mimicry in the development of postinfectious autoimmunity are currently very intriguing. They provide new approaches for identifying etiological agents that are associated with postinfectious autoimmunity, paired microbial- and tissue-linked epitopes targeted for autoimmune reaction determination, postinfectious autoimmunity pathogenesis recognition and specific prevention, and therapy for autoimmune disorder development.     

Beta-endorphin and drug-induced reward and reinforcement

Although drugs of abuse have different acute mechanisms of action, their brain pathways of reward exhibit common functional effects upon both acute and chronic administration. Long known for its analgesic effect, the opioid beta-endorphin is now shown to induce euphoria, and to have rewarding and reinforcing properties. In this review, we will summarize the present neurobiological and behavioral evidences that support involvement of beta-endorphin in drug-induced reward and reinforcement. Currently, evidence supports a prominent role for beta-endorphin in the reward pathways of cocaine and alcohol. The existing information indicating the importance of beta-endorphin neurotransmission in mediating the reward pathways of nicotine and THC, is thus far circumstantial. The studies described herein employed diverse techniques, such as biochemical measurements of beta-endorphin in various brain sites and plasma, and behavioral measurements, conducted following elimination (via administration of anti-beta-endorphin antibodies or using mutant mice) or augmentation (by intracerebral administration) of beta-endorphin. We suggest that the reward pathways for different addictive drugs converge to a common pathway in which beta-endorphin is a modulating element. beta-Endorphin is involved also with distress. However, reviewing the data collected so far implies a discrete role, beyond that of a stress response, for beta-endorphin in mediating the substance of abuse reward pathway. This may occur via interacting with the mesolimbic dopaminergic system and also by its interesting effects on learning and memory. The functional meaning of beta-endorphin in the process of drug-seeking behavior is discussed.     

PTEN与信号转导及肿瘤

ＴＥＮ[1] (ｐｈｏｓｐｈａｔａｓｅａｎｄｔｅｎｓｉｎｈｏｍｏｌｏｇｙｄｅｌｅｔｅｄｏｎｃｈｒｏｍｏｓｏｍｅｔｅｎ)又名ＭＭＡＣ1 [2 ] (ｍｕｔａｔｅｄｉｎｍｕｔｉｐｌｙａｄａｎｃｅｄｃａｎｃｅｒ 1 )和ＴＥＰ1 [3 ] (ＴＧＦ -βｒｅｇｕｌａｔｅｄａｎｄｅｐｉｔｈｅｌｉａｌｃｅｌｌ -ｒｉｃｈｅｄｐｈｏｓｐｈａｔａｓｅ 1 ) (以下均称为ＰＴＥＮ) ,是 1 997年由 3个研究小组先后发现的一个具有双特异磷酸酶活性的抑癌基因。ＰＴＥＮ基因异常广泛存在于人类多种恶性肿瘤 ,如恶性神经胶质瘤、前列腺癌、子宫内膜癌、黑色素瘤等…     

Tobacco and alcohol and the risk of head and neck cancer

Summary We carried out two case-control studies on the relative risk of head and neck cancer in association with tobacco and alcohol consumption. The first study carried out at the ENT Department of the University hospitals of Heidelberg and Giessen (FRG) comprised 200 male patients with squamous cell cancer of the head and neck and 800 control subjects matched for sex, age, and residential area (1:4 matching design). Of the tumour patients, 4.5% had never smoked, in contrast to 29.5% of the control group. The average tobacco and alcohol consumption of the patients was approximately twice as high as in the control subjects. The highest alcohol and tobacco consumption was observed in patients suffering from oropharyngeal cancer. Tobacco and alcohol increased the risk of head and neck cancer in a dose-dependent fashion and acted as independent risk factors. In heavy smokers (> 60 pack-years) a relative risk of 23.4 (alcohol adjusted) was calculated. Combined alcohol and tobacco consumption showed a synergistic effect. The risk ratio increased more in a multiplicative than in an additive manner. Oral and laryngeal cancer were associated with the highest tobacco-associated risk values. The highest ethanol-associated risk values were associated with oropharyngeal and laryngeal cancer. The second study was carried out at the ENT Department of the University of Heidelberg on 164 males with squamous cell carcinoma of the larynx and 656 control subjects matched for sex, age and residential area (1:4 matching design). Of the cases, 4.2% had never smoked, compared with 28.5% of the control subjects. The risk of laryngeal cancer by tobacco consumption was dose dependent, reaching a maximum value of 9.1 (adjusted for alcohol) for a consumption of more than 50 tobacco-years (TY). The relative risk of laryngeal cancer associated with alcohol intake was also dose dependent, reaching a value of 9.0 (adjusted for tobacco) for a mean daily consumption of more than 75 g alcohol. An analysis of subsite specific risks showed that heavy smokers (> 50 TY) carried a nearly ten times higher risk of supraglottic cancer than of glottic cancer. The risk of supraglottic cancer from alcohol consumption was also higher than that of glottic cancer.     

Muscle strength and serum testosterone,cortisol and SHBG concentrations in middle-aged and elderly men and women

Forty healthy males (M) and females (F) divided into two different age groups i.e. M50 years (range 44–57; n= 9), F50 years (range 43–54; n= 9), M70 years (range 64–73; n= 11) and F70 years (range 63–73; n= 11) volunteered as subjects for examination of muscle cross-sectional area (CSA) and maximal voluntary isometric force production characteristics of the leg extensor muscles and serum androgen and sex hormone binding globulin (SHBG) concentrations. The CSA in the male groups was greatly larger (P < 0.01) than in the female groups and both elderly groups demonstrated slightly (n.s.) smaller values in the CSA than the two middle-aged groups. Maximal force of 2854 ± 452 N in M50 was greater (P < 0.05) than that of 2627 ± 752 N recorded for F50 as well as the force of 2787 ± 843 in M70 was greater (P < 0.001) than that of 1849 ± 295 recorded for F70. The force between F50 and F70 differed significantly (P < 0.05) from each other. The maximal rate of force production in M50 was greater (P < 0.01) than in F50 as well as in M70 greater (P < 0.001) than in F70. Both middle-aged groups demonstrated greater (P < 0.05) values than the respective elderly groups of the same sex. The individual values in the CSA correlated with the values in maximal force both in the middle-aged subjects (r= 0.66; P < 0.01) and in the elderly subjects (r= 0.69; P < 0.01). The mean concentration of serum testosterone in M50 was slightly (n.s.) greater than in M70 and in F50 significantly (P < 0.05) greater than in F70. Serum SHBG levels were lower in the males (P < 0.01) than in the females and serum testosterone/SHBG ratio in M70 and in F70 were lower (P < 0.05) than in M50 and in F50, respectively. In the females significant positive correlations were observed between the individual values in serum testosterone concentration and the values both in the CSA (r= 0.46; P < 0.05) and in maximal force (r= 0.62; P < 0.01) as well as between serum testosterone/SHBG ratio and both the CSA (r= 0.55; P < 0.05) and maximal force (r= 0.68; P < 0.01). The present results imply that the decreasing basal level of blood testosterone over the years in aging people, especially in females, may lead to decreasing anabolic effects on muscles thus having an association with age-related declines in the maximal voluntary neuromuscular performance capacity in aging people.     

Platelet-activating factor receptor and respiratory and metabolic responses to hypoxia and hypercapnia

Activation of the platelet-activating factor receptor (PAFR) regulates neural transmission. A PAFR blocker reduced the peak hypoxic (pHVR) but not hypercapnic ventilatory (HCVR) responses in rats [Am. J. Physiol. 275 (1998) R604]. To further examine the role of PAFR in respiratory control, genotype-verified PAFR -/- and PAFR +/+ adult male mice underwent hypoxic and hypercapnic challenges. HCVR was similar in the two groups (p-NS). However, pHVR was significantly reduced in PAFR -/- mice (38 +/- 13% baseline [S.D.]) compared to PAFR +/+ mice (78 +/- 16% baseline; P < 0.001, ANOVA), with reduced tidal volume recruitments during pHVR. In addition, hypoxic ventilatory depression was attenuated in PAFR -/- mice (P < 0.01), and was primarily due to attenuation of the time-dependent decreases in oxygen consumption during sustained hypoxia (P < 0.01). Thus, PAFR expression/function modulates components of the acute ventilatory and metabolic adaptations to hypoxia but not to hypercapnia. Imbalances in PAFR activity may lead to maladaptive regulation of the tightly controlled metabolic-ventilatory relationships during hypoxia.