白光内镜联合内镜超声对早期胃癌浸润深度的判断

目的 探讨术前应用白光内镜联合内镜超声检查（endoscopic ultrasonography,EUS）评估浅表胃癌浸润深度的价值。方法 回顾性分析2011年1月—2019年12月于首都医科大学附属北京世纪坛医院经胃镜病理确诊的浅表胃癌患者资料,将术前白光内镜及EUS资料完整,并在该院接受治疗的84例患者纳入研究。根据内镜医师对白光内镜判读结果的自信与否,将患者分为白光内镜确定组（47例）和白光内镜不确定组（37例）,以术后病理为金标准,评估白光内镜及EUS对浅表胃癌浸润深度判断的准确性,及对治疗决策的影响。结果 白光内镜和EUS判断浅表胃癌浸润深度的总准确率分别为73.8%（62/84）和81.0%（68/84）,差异无统计学意义（P=0.092）。白光内镜确定组白光内镜判断胃癌浸润深度的准确率为93.6%（44/47）,高于白光内镜不确定组的48.7%（18/37）（χ2=21.656,P<0.001）。84例患者中20例（23.8%）被白光内镜高估浸润深度,其中8例（40.0%）经EUS修正诊断。多因素Logistic回归分析发现,病变表面不规则（OR=5.076,95%CI：1.628~15.821,P=0.005）、病变边缘显著隆起（OR=3.831,95%CI：1.238~11.857,P=0.020）和病理类型是未分化型癌（OR=6.887,95%CI：1.882~25.204,P=0.004）是影响读图医师信心的独立危险因素。结论 对于浅表胃癌,白光内镜确定病变浸润深度者,白光内镜诊断准确率高;白光内镜不确定浸润深度者,联合EUS能提高诊断准确率,利于制定更合适的治疗方案。     

内镜黏膜下剥离术治疗未分化型早期胃癌的疗效分析

目的 探讨内镜黏膜下剥离术（ESD）治疗未分化型早期胃癌的疗效及预后。方法 回顾性分析2010年1月—2019年4月在南京医科大学第一附属医院行ESD治疗且术后病理证实为早期胃癌的393例患者（400处病灶）的临床病理资料,根据术后病理结果分为未分化癌组（50例,50个病灶）和分化癌组（343例,350个病灶）,收集患者年龄、性别,切除病灶大小及部位、大体分型、浸润深度、有无溃疡及术后随访情况等进行分析。结果 Logistic回归分析表明年龄≤60岁（OR=2.02,95%CI：1.04~3.95,P=0.011）、女性（OR=2.83,95%CI：1.41~5.68,P=0.003）、胃窦部病变（OR=3.92,95%CI：1.65~9.30,P=0.002）、凹陷型病变（OR=5.37,95%CI：2.16~13.38,P<0.001）及浸润至黏膜下层（OR=5.09,95%CI：2.40~10.80,P<0.001）为未分化型早期胃癌发生的独立危险因素。393例患者中,非治愈性切除113例,治愈性切除280例。未分化癌组非治愈性切除率高于分化癌组[90.0%（45/50）比19.8%（68/343）,χ2=104.902,P<0.001]。非治愈性切除患者死亡率高于治愈性切除[4.4%（5/113）比0.7%（2/280）, χ2=5.558,P=0.023]。未分化癌组27例患者追加手术,分化癌组51例追加手术,无一例复发;315例未追加手术患者中,未分化癌组复发率高于分化癌组[26.1%（6/23）比4.1%（12/292）,χ2=5.560,P<0.001]。结论 年龄≤60岁、女性、胃窦部病变、凹陷型病变及浸润至黏膜下层为未分化型早期胃癌发生的独立危险因素。未分化型早期胃癌非治愈性切除率高、ESD术后易复发,建议追加外科手术治疗。     

早期胃癌淋巴结转移的影响因素分析

目的 通过分析早期胃癌临床病理特征,探讨淋巴结转移相关危险因素。 方法 回顾性分析2014年1月至2017年12月在华山医院行胃癌根治术,且术后病理证实为早期胃癌的303例患者的临床病理资料。收集年龄、性别、肿瘤大小、病变部位、大体分型、有无溃疡、分化类型、有无印戒细胞、有无脉管侵犯、肿瘤浸润深度、有无淋巴结转移等指标。对单因素分类变量使用卡方检验,有统计学意义的单变量采用Logistic回归模型分析。 结果 本研究共纳入303例早期胃癌患者,淋巴结转移阳性患者45例（14.9%）。黏膜内癌淋巴结转移率为7.1%（14/198）,侵及黏膜下层时淋巴结转移率为29.5%（31/105）。单因素分析结果显示,患者年龄、肿瘤大小、大体分型、浸润深度、脉管累及、分化类型与淋巴结转移相关（P<0.05）。多因素分析提示,肿瘤的浸润深度（OR=3.701,95%CI：1.748~7.836,P=0.001）、脉管累及（OR=2.929,95%CI：1.090~7.870,P=0.033）、分化类型（OR=0.352,95%CI：0.164~0.757,P=0.008）是淋巴结转移的独立危险因素。 结论 肿瘤浸润深度、脉管累及和分化类型为早期胃癌患者淋巴结转移的独立危险因素。对于选择内镜切除的早期胃癌患者,应警惕上述危险因素,对于淋巴结转移高风险患者密切随访,必要时追加外科手术。     

老年未分化型早期胃癌淋巴结转移的危险因素分析

目的总结老年患者未分化型早期胃癌（early gastric cancers,EGCs）的临床病理特征,分析未分化型EGCs淋巴结转移的危险因素。方法纳入2010年1月—2019年8月在北京协和医院行根治性胃癌切除+淋巴结清扫术,手术病理诊断符合EGCs的老年（≥65岁）患者,以分化型EGCs为对照,比较分析未分化型EGCs（即印戒细胞癌和低分化腺癌）的临床病理特征。用Logistic回归对老年未分化型EGCs淋巴结转移风险进行多因素分析。结果纳入老年EGCs共165例,其中未分化型EGCs 82例（印戒细胞癌11例,低分化腺癌 71例）,分化型EGCs 83例。淋巴结转移率方面,老年EGCs淋巴结转移率为9.1%（15/165）,分化型EGCs淋巴结转移率为4.8%（4/83）,未分化型EGCs淋巴结转移率为13.4%（11/82）。未分化型EGCs中,低分化腺癌淋巴结转移率为15.5%（11/71）,印戒细胞癌11例均无淋巴结转移。单因素分析提示浸润深度（P=0.019)、病变大小（P=0.006）、合并溃疡（P=0.006）、凹陷型（P=0.003）与老年未分化型EGCs淋巴结转移相关。多因素分析提示黏膜下层浸润（OR=11.98,95%CI:1.17~122.84,P=0.037 ）、病变直径＞2 cm（OR=11.95,95%CI:1.88~76.07,P=0.009)是老年未分化型EGCs淋巴结转移的独立危险因素。所有满足扩大适应证的老年未分化型EGCs无淋巴结转移。结论黏膜下层浸润、病变直径＞2 cm是老年未分化型EGCs淋巴结转移的独立危险因素。满足扩大适应证的老年未分化型EGCs患者适合内镜黏膜下剥离术治疗。     

超声内镜对胃癌外科手术及内镜下黏膜可切除性的评价

目的: 阐述EUS对术前胃癌浸润深度(T分期)诊断的准确性, 评价其对胃癌手术或内镜下黏膜可切除性的指导意义.方法: 回顾性分析78例胃癌手术患者临床资料. 患者术前均行超声内镜检查, TNM分期.分析比较术前T分期与术后手术及病理结果.结果: 与术后病理结果对比, EUS术前T分期总准确率为69.2%, T1、T2、T3、T4分期的准确率分别为83.3%、61.9%、40.0%和100%, 对手术可切除性预测的敏感性为80.8%(63/78).其中EUS准确诊断早期胃癌5例, 但1例胃黏膜下层癌, 被诊断为固有肌层癌. T4期胃癌手术切除率仅为42.3%(11/26).结论: EUS对判断胃癌浸润深度准确率较高, 能较准确诊断早期胃癌, 对指导内镜下黏膜切除术有很大帮助. 而对T4期胃癌患者, 虽然诊断准确性很高, 但对指导根治性手术的意义不大.     

术前内镜评估结直肠侧向发育型肿瘤浸润深度的临床研究

目的对比放大染色内镜（MCE）、内镜超声检查术（EUS）术前评估结直肠侧向发育型肿瘤（LST）浸润深度的准确率。方法纳入104例结直肠LST,以病理诊断为金标准,回顾性比较MCE和EUS术前评估结直肠LST浸润深度的准确率。结果MCE和EUS的总体准确率分别为89.4%（93/104）和73.1%（76/104）（P＜0.05）。病变大小、检查医生因素会影响EUS评估的准确率（P=0.017,OR=3.561;P=0.035,OR=1.399）。在直径较大的结直肠LST病变中,EUS评估的准确率有下降趋势。结论MCE和EUS均为评估结直肠LST病变浸润深度的有效方法。MCE评估结直肠LST病变浸润深度的准确率可能高于EUS。病变直径大、检查医生经验不足可能是影响EUS检查准确率的危险因素。     

超声内镜检查评价早期胃癌黏膜下浸润的价值

目的评价超声内镜(endoscopic ultrasonography,EUS)鉴别早期胃癌病变中黏膜内癌与黏膜下层癌的价值。方法对61例早期胃癌病变进行EUS扫查,判断病变浸润深度,重点观察黏膜下浸润状况,并与手术和内镜治疗病理学诊断作对照。结果61例早期胃癌病变EUS浸润深度判断准确率75.4%,其中对病变局限于黏膜内的高级别上皮内瘤变和黏膜内癌判断准确率为73.9%,黏膜下层癌准确率为80.0%,两者差异无统计学意义(P0.05)。而对高级别上皮内瘤变和黏膜内癌EUS判断敏感性为73.9%,特异性为93.3%。结论 EUS对判断早期胃癌浸润深度具有较好价值。对于EUS判断黏膜内病变者,可作为早期胃癌内镜治疗一个术前适应证评价依据。     

早期胃癌淋巴结转移规律的临床病理因素研究

目的探讨早期胃癌临床病理因素与淋巴结转移规律的相关性。方法回顾性分析2012年1月—2018年12月期间在陆军军医大学第一附属医院经胃镜下活检病理确诊,并实施外科根治手术的早期胃癌病例,采用单因素分析及Logistic回归多因素分析相关临床病理因素与各组淋巴结转移的关系。结果164例早期癌患者中,34例出现转移。单因素分析显示病理分化程度、浸润深度、肿瘤最大径、脉管浸润与早期胃癌淋巴结转移相关(P均<0.05)。Logistic回归多因素分析结果显示:肿瘤最大径>2 cm(OR=3.2,95%CI:2.305~4.187)、浸润至黏膜下层(OR=2.5,95%CI:2.091~3.859)、病理分化不良(OR=1.7,95%CI:1.029~2.933)及脉管侵犯(OR=2.1,95%CI:1.817~3.176)是早期胃癌淋巴结转移的独立影响因素(P均<0.05)。上部癌中转移率较高的淋巴结依次是第1组(66.7%)、第3组(33.3%);中部癌中转移率较高的淋巴结依次是第3组(75.0%)、第4组(25.0%);下部癌中转移率较高的淋巴结依次是第6组(33.3%)、第3组(25.9%)、第4组(25.9%)及第7组(14.8%)。从转移站别看,分化良好且肿瘤直径≤2 cm的黏膜内早期癌,各部位癌第1站均未见淋巴结转移。结论早期胃癌肿瘤最大径>2 cm﹑浸润至黏膜下层﹑病理分化程度低及脉管受侵犯是淋巴结转移的危险因素。上、中、下部癌均有其各自的高发区域,早期胃癌的淋巴结胃周转移基本符合由近及远的规律。     

早期胃癌内镜下特征对内镜下切除术非治愈性切除的预测意义

目的探讨早期胃癌行内镜下切除术治疗易发非治愈性切除的内镜下特征,并尝试以此构建一项非治愈性切除危险度的评估工具以量化非治愈性切除风险。方法2006年8月—2019年10月,在北京协和医院消化内科接受内镜下切除术治疗,病理为早期胃癌的378处病变纳入病例对照研究。其中78处（20.6%）为非治愈性切除纳入观察组,剩余300处治愈性切除病变中按操作年份相差±1年以1∶3的比例匹配纳入对照组（共234处）。采用单因素联合多因素Logistic回归分析探寻非治愈性切除易发因素,将最小β系数对应的独立危险因素赋1分,其余因素按其β系数与该最小β系数的比值进行赋分,以此建立非治愈性切除预测模型,并采用该模型对完整的378处病变进行分析,观察各评分段的非治愈性切除率。结果单因素分析结果显示,病变直径、位置、发红、溃疡或溃疡瘢痕、皱襞中断、皱襞纠集和超声内镜提示浸润深度与早期胃癌病变非治愈性切除相关（P＜0.05）,而接触或自发出血可能与非治愈性切除相关（P=0.068）。进一步多因素Logistic回归分析结果显示,EUS提示累及黏膜下层（VS 局限于黏膜内：β=0.901,P=0.011,OR=2.46,95%CI：1.23～4.92）、病变直径3～＜5 cm（VS ＜3 cm：β=0.723,P=0.038,OR=2.06,95%CI：1.04～4.09）、病变直径≥5 cm（VS ＜3 cm：β=2.078,P=0.003,OR=7.99,95%CI：2.02～31.66）、病变位于胃上1/3（VS 胃下1/3：β=1.540,P＜0.001,OR=4.66,95%CI：2.30～9.45）、有皱襞中断（β=2.287,P=0.008,OR=1.93,95%CI：0.95～3.93）均是早期胃癌病变发生非治愈性切除的独立危险因素。将因素直径3～＜5 cm赋1分,超声内镜提示累及SM层赋1分,病变位于胃上1/3赋2分,直径≥5 cm和有皱襞中断各赋3分,其他因素均赋0分,再对完整的378处病变进行分析后发现,评分≥2分时病变发生非治愈性切除的概率达41.9%（37/93）,约是评分0分时[11.5%（25/217）]的4倍。结论直径≥3 cm、位于胃上1/3、有皱襞中断和超声内镜提示累及黏膜下层是早期胃癌行内镜下切除术治疗易发生非治愈性切除,以此构建的预测模型具有较好的预测价值但还需积累病例进一步验证。     

未分化型早期胃癌内镜黏膜下剥离术扩大适应证的可行性探讨

目的评估未分化型早期胃癌内镜黏膜下剥离术(ESD)扩大适应证的可行性,探讨淋巴结转移的危险因素,为治疗方案的选择提供理论依据。方法回顾性分析2007年6月至2018年12月在青岛大学附属医院接受胃切除加淋巴结清扫术的807例未分化型早期胃癌患者的临床资料。采用卡方检验分析早期胃癌临床病理特征与淋巴结转移的关系,logistic回归模型分析淋巴结转移的独立危险因素。结果17.2%(139/807)的未分化型早期胃癌患者发生淋巴结转移,110例符合ESD扩大适应证的患者均未发生淋巴结转移。单因素分析结果显示淋巴结转移与癌胚抗原水平升高、肿瘤大小、大体分型、溃疡、浸润深度、脉管侵犯、神经侵犯均有关(χ^2=4.500、13.332、16.611、6.083、51.064、0.564、17.006,P均<0.05)。多因素分析结果表明,肿瘤最大径>20 mm(OR=1.606,95%CI 1.021~2.526,P=0.040)、脉管侵犯(OR=16.835,95%CI 10.510~26.966,P<0.01)、黏膜下浅浸润(≤500μm;OR=1.962,95%CI 1.022~3.765,P=0.043)和黏膜下深浸润(>500μm;OR=3.014,95%CI 1.753~5.181,P<0.01)均是早期胃癌淋巴结转移的独立危险因素。结论未分化型早期胃癌的ESD扩大适应证适用于内镜下治疗,患者发生淋巴结转移的风险较低;肿瘤最大径>20 mm、脉管侵犯、黏膜下浅浸润和黏膜下深浸润均是未分化型早期胃癌淋巴结转移的独立危险因素。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.     

Morphological and immunocytochemical heterogeneity of cultured pinealocytes from one-week-and two-month-old rats: Planimetric and densitometric investigations

Abstract: In vitro preparations of rat pinealocytes are widely used for biochemical analyses of signal transduction processes. This paper deals with morphological and immunocytochemical features of such preparations. Special attention was paid to the problems of whether pinealocytes represent a heterogeneous cell population and how such heterogeneity may develop during ontogeny. The investigations were performed with cells which were obtained from the pineal organ of one-week-and two-month-old rats, attached to synthetic peptide-coated coverslips or tissue culture chamber slides, and maintained under in vitro conditions overnight. The attached cells were then fixed with paraformaldehyde. These preparations yielded monolayers of spherical cells of different sizes; most cells were isolated, but some of them were aggregated and formed small clusters. On the average, the cells from the one-week-old animals were smaller than the cells from the two-month-old animals. Immunocytochemical demonstration of S-antigen, a pinealocyte-specific marker, showed that the majority of the cells from two-month-old animals were intensely or moderately labelled. Pinealocytes from one-week-old animals were less S-antigen immunoreactive. Only very few cells (less than 1% displayed glial fibrillary acidic protein (GFAP)-immunoreactivity. Planimetric investigations of the cell size and semiquantitative densitometric investigations of the intensity of the S-antigen immunoreaction revealed that (i) pinealocytes kept in vitro form a heterogeneous cell population, and that (ii) this heterogeneity increases during postnatal development from one-week-old to two-month-old animals. Two groups of pinealocytes can be distinguished based on their developmental fate: pinealocytes of one group grow dramatically, but show only a moderate increase in S-antigen immunoreactivity, and pinealocytes of the other group retain their size, but display a distinct increment in S-antigen immunoreacti vitv.     

MUTATION FREQUENCY IN NURSES AND PHARMACISTS WORKING WITH CYTOTOXIC DRUGS

Individuals occupationally exposed to cytotoxic drugs may be at risk owing to the effects of these agents on DNA. As an index of DNA damage, in vivo mutations were measured in lymphocytes from 24 oncology nurses or pharmacists and 24 matched controls. Mutation frequency was significantly increased in exposed individuals and appeared to be related to duration of exposure. However, the overall magnitude of the increase was small and its biological significance remains to be determined.