胃微小腺癌的组织发生研究

从２１０５例胃癌癌旁组织中找出微小腺癌３１例（〈０．１ｃｍ），观察其组织发生的特征，发现胃腺癌的发生有８种形式：①腺颈部干细胞癌变；②表面上皮癌变；③腺上皮癌变；④肠化生上皮癌变；⑤微腺囊癌变；⑥溃疡边缘上皮癌变；⑦扁平腺瘤癌变；⑧贲门交界处柱状上皮癌变。     

conference report: Mental health and intellectual disability: an international perspective

The present paper reports on the inaugural meeting of the Mental Health Special Interest Research Group (SIRG) of the International Association for the Scientific study of Intellectual disability which was held at Fitzwilliam College, Cambridge, UK, in March 1998. The meeting was organized in conjunction with the Ninth Annual SIRG on ageing and intellectual disability. Representatives from North America, several European and Scandinavian countries, Australia, and Israel attended. Two broad themes had been determined prior to the meeting: ‘Improving the detection of mental health problems’ and ‘Research strategies for identifying risk factors for mental health problems’. In the presentations and subsequent discussions, it was apparent that there were extrenely diverse perspectives both across and within the different countries represented. Not only were individuals' experiences very different, but most strikingly, the theoretical frameworks were very diverse. This was partly a function of there being understandable differences in perspectives across disciplines, but at its most marked, there were fundamental differences in the way both intellectual disability and mental health were conceptualized.     

急性病毒性肝炎住院患者血清学分型与流行病学分布研究

本文收集了西安市住院急性病毒性肝炎患者血清标本２９３份，用ＥＬＩＳＡ进行分型检测，并作流行病学调查。结果发现：甲肝占６５．１９％，乙肝占１０．９２％，丙肝占４．７８％，丁肝占３．７５％，戊肝占４．４４％，诊断不明者占１０．９２％。结果表明，在西安市住院的急性病毒性肝炎中，甲肝为主要类型；与以往结果比较，甲肝患者的发病年龄明显后移；除乙肝外，各型肝炎中男性均多于女性，尤以丁肝和戊肝为著；甲肝有明显的     

Recovery from short term intense exercise: Its relation to capillary supply and blood lactate concentration

Summary Muscle force recovery from short term intense exercise was examined in 16 physically active men. They performed 50 consecutive maximal voluntary knee extensions. Following a 40-s rest period five additional maximal contractions were executed. The decrease in torque during the 50 contractions and the peak torque during the five contractions relative to initial torque were used as indices for fatigue and recovery, respectively. Venous blood samples were collected repeatedly up to 8 min post exercise for subsequent lactate analyses. Muscle biopsies were obtained from m. vastus lateralis and analysed for fiber type composition, fiber area, and capillary density. Peak torque decreased 67 (range 47–82%) as a result of the repeated contractions. Following recovery, peak torque averaged 70 (47–86%) of the initial value. Lactate concentration after the 50 contractions was 2.9±1.3 mmol·l⁻¹ and the peak post exercise value averaged 8.7±2.1 mmol·l⁻¹. Fatigue and recovery respectively were correlated with capillary density (r=−0.71 and 0.69) but not with fiber type distribution. A relationship was demonstrated between capillary density and post exercise/peak post exercise blood lactate concentration (r=0.64). Based on the present findings it is suggested that lactate elimination from the exercising muscle is partly dependent upon the capillary supply and subsequently influences the rate of muscle force recovery. Dr. Tesch was on leave from Department of Clinical Physiology, Karolinska Hospital, Stockholm, Sweden     

Pathomorphological characteristics of cardiac remodeling after myocardial infarction

Dilatational, hypertrophic, aneurysmal, and endocardial variants of remodeling were revealed in the postinfarction heart. The most prevalent dilatational remodeling is characterized by uniform or nonuniform elongation of ventricular cavities and increase in ventricular volume. Characteristic features of the hypertrophic type are hypertrophied interventricular septa and left ventricular wall and reduced or unchanged left ventricular volume. Pronounced changes in the configuration of the left ventricle due to the formation of single or multiple aneurysms were typical of aneurysmal remodeling. Endocardial remodeling was characterized by cicatricial changes and smoothed relief of the parietal endocardium. These variants and forms of remodeling determine disturbances in intracardial hemodynamic and thanatogenesis in the postinfarction period.     

Shortening velocity and force/pCa relationship in skinned crab muscle fibres of different types

Single fibres of three different types, which had been characterized histochemically with regard to differences in myofibrillar adenosine triphosphatase (ATPase) activity and its pH stability, were microdissected from freeze dried preparations of the closer muscle in walking legs of the crab Eriphia spinifrons. Shortening velocities were determined in slack tests and under constant load conditions in maximally Ca²⁺-activated skinned muscle fibres. Force/pCa relationships were also measured for the different types of fibres. Compared with data on vertebrate muscles, all crab muscle fibres required large length changes to reach zero force and showed low Ca²⁺ sensitivity for isometric force generation. The length/time relationship obtained from slack tests had a biphasic course. Maximal velocity of filament sliding differed in the three types of fibres investigated. The filament sliding of type IV fibres was about 3 times faster than that of type I fibres. The values obtained for type II fibres ranged in between. These data are positively correlated with myofibrillar ATPase activity determined histochemically. Ca²⁺ sensitivity of force generation was lowest in the fast type IV fibres. It was high in the slow type I and the faster contracting type II fibres. Ca²⁺ sensitivity in crab muscle seems not to be correlated with speed of shortening.     

Different thermal conditions of the extremities affect thermoregulation in clothed man

The effects of different types of clothing on human deep body temperature were studied with six healthy male subjects in a supine posture. Two clothing ensembles were employed for the present study: A covered the whole body area with garments except the face (1.97 clo) and B covered only the trunk and the upper half of the extremities with garments (1.53 clo). The experiment was carried out in a climatic chamber at 55% ± 5% relative humidity under cooling and warming temperatures: the temperature was changed from 22°C to 10°C (cooling) and returned to 22°C again (warming). The major findings were: rectal temperature (T _re) continued to decrease gradually in A throughout the experiment, whereas in B it increased during cooling, and returned to previous levels during warming. As a result, Tre and chest skin temperature were maintained at a higher level in B than in A. Internal tissue conductances were greater in A than in B both during cooling and during warming. Thermal comfort appeared to have been influenced more by the rate of skin temperature change than by the level of skin temperature per se. It was concluded that peripheral vasoconstriction in B induced less heat flow from core to shell, and, thus, the core temperature was maintained at a higher level in B than in A.     

Impact of Breast Density on Computer-Aided Detection in Full-Field Digital Mammography

The goal of this study was to evaluate the performance of a computer-aided detection (CAD) system in full-field digital mammography (Senographe 2000D, General Electric, Buc, France) in finding out carcinomas depending on the parenchymal density. A total of 226 mediolateral oblique (MLO) and 186 craniocaudal (CC) mammographic views of histologically proven cancers were retrospectively evaluated with a digital CAD system (ImageChecker V2.3 R2 Technology, Los Altos, CA, USA). Malignant tumors were detected correctly by CAD in MLO view in 84.85% in breasts with parenchymal tissue density of the American College of Radiology (ACR) type 1, in 70.33% of the ACR type 2, in 68.12% of the ACR type 3, and in 69.70% of the ACR type 4. For the CC view, similar results were found according to the ACR types. Using the chi-square and McNemar tests, there was no statistical significance. However, a trend of better detection could be seen with decreasing ACR type. In conclusion, there seems to be a tendency for breast tissue density to affect the detection rate of breast cancer when using the CAD system.     

Fast- and slow-twitch isoforms (SERCA1 and SERCA2a) of sarcoplasmic reticulum Ca-ATPase are expressed simultaneously in chronically stimulated muscle fibers

 Using an immunohistochemical double-labeling technique, we observed that different isoforms of sarcoplasmic reticulum Ca-ATPase are co-expressed in single fibers of canine fast-twitch skeletal muscles stimulated chronically at low frequency. By 7 days of neuromuscular stimulation, the population of hybrid fibers expressing both SERCA1 and SERCA2a [fast- and slow-twitch isoforms of sarco(endo)plasmic reticulum Ca²⁺-ATPase] had increased from 1.5% to 9.2% of fibers. By 14 days of stimulation 90% of the pure fast-twitch fibers (expressing only SERCA1) were replaced by hybrid fibers. An additional 28 days of stimulation caused all fast-twitch fibers to express SERCA2a at the same level as found in nonstimulated slow-twitch fibers (expressing only SERCA2a). At this time, one-half of the previously hybrid fibers had become pure slow-twitch fibers. The remaining one-half of the hybrid fibers expressed SERCA1 at a very low level. Extending stimulation to 70 days did not further change the percentage of fibers that were slow-twitch or hybrid. Immunoblot studies at the whole-muscle level confirmed that changes in SERCA expression at 42 days of neuromuscular stimulation were complete. Immunohistochemical analysis of longitudinal sections of muscle showed that the changes in SERCA protein were uniform along the length of the muscle fiber, indicating that nuclei along its length responded equally to chronic stimulation. Received: 12 November 1996 / Received after revision and accepted: 16 December 1996     

The human oral raphe system

Summary Serial sections (15 m, 120 m, and 400 m) of nine brain stems treated with a combined lipofuscin pigment-Nissl stain were examined in order to delineate the three-dimensional conformation and subdivisions as well as the neuronal types of the human oral raphe system. Characteristic lipofuscin deposits within the somata of various cell types facilitated the demarcation of the oral raphe nuclei from surrounding structures. The dorsal, central, and linear raphe nuclei, e.g. the major subdivisions of the oral raphe system, share common traits as far as neuronal composition and pigmentation is concerned. The interfascicular subnucleus, the dorsofascicular subnucleus, and the intercalate subnucleus are minor subdivisions of the dorsal raphe nucleus. The intercalate one cannot be differentiated from surrounding areas in preparations solely stained for Nissl-material, while it can facilely be identified in combined pigment-Nissl preparations by virtue of differences in the pigmentation pattern. Our architectonical concept of the oral raphe system is in good accordance with the one derived from immunocytochemical investigations of serotonin-containing neurons in the human brain stem. Furthermore, five main neuronal types are described which constitute the oral raphe nuclei. They have been differentiated according to their characteristics as seen in combined pigment-Nissl preparations. I) Large ovoid to polygonal neurons with densely packed and intensely stained pigment granules. II) Similarily featured cells displaying dust-fine and faintly stained pigment granules. III) Medium-sized, ovoid to polygonal neurons with loosely distributed, small pigment granules. IV) Small ovoid neurons devoid of pigment or with only few, intensely stained granules. V) Small spindleshaped nerve cells with various amounts of intensely stained pigment granules. The morphometrical examination has revealed considerable overlapping in size between types I and II. A fact that would not allow a distinction in preparations solely stained for Nissl-material.