利用同期发情技术对和田羊繁殖效果的试验研究

本试验采用阴道埋置孕酮海绵栓＋肌肉注射PMSG法和肌肉注射PC法对处于正常发情周期内的策勒黑羊进行同期发情处理,再进行人工授精技术后直至产羔,对母羊的发情率进行分析。结果表明,经过处理后的母羊发情时间集中,周岁母羊发情率提高了23．5％,成年母羊发情率提高了13．6％．周岁母羊受胎率提高了51．5％,成年母羊受胎率提高了27．4％,极显著提高（P〈0．01）。本试验针对和田策勒县专业户,采用同期发情、人工授精等技术处理方法,为提高策勒黑羊产羔率和优化生产提供试验依据。     

射线对血管平滑肌细胞抑制作用的机制

血管腔内放疗预防经皮穿刺冠状动脉血管成形术(PTCA)后再狭窄的临床应用取得了令人瞩目的疗效。人们认为,射线预防PTCA后血管再狭窄主要是射线对血管平滑肌细胞产生的抑制作用,但是这种抑制作用的机制尚不十分清楚,目前认为最关键的因素是射线抑制了血管平滑肌细胞的迁移和增殖,凋亡在射线抑制再狭窄过程中所起的作用尚存在争议。在这个过程中,射线对巨噬细胞和多种细胞因子的抑制作用也逐步受到人们的重视。     

MR imaging of hemorrhagic conditions of the head and neck

1. There is a constant sequence of signal intensity patterns that characterize 1.5 T, spin echo MR images of hemorrhagic lesions. 2. The MRI appearance of intraparenchymal hemorrhage is determined by the sequential chemical degradation of Hb, by the paramagnetic properties of the degradation products and by certain biologic factors including pO2, edema formation, hematocrit and BBB. 3. Acute intraparenchymal hemorrhage is characterized by markedly diminished signal intensity centrally relative to surrounding white matter (hypointensity) on T2 weighted images and often by a moderately increased signal intensity (hyperintensity) of the adjacent white matter produced by surrounding edema on proton density and T2 weighted images. 4. Early subacute intraparenchymal hemorrhage is characterized centrally by moderate hypointensity on T2 weighted images, and peripherally, by moderate hyperintensity on T1 weighted and marked hypointensity on T2 weighted images. Hyperintensity on proton density and T2 weighted images of nearby white matter owing to edema may again be seen. 5. Late subacute intraparenchymal hemorrhage is characterized by marked peripheral and central hyperintensity on both T1 and T2 weighted images. Also, marked hypointensity of the adjacent brain rim on T2 weighted images owing to hemosiderin deposition may be seen. 6. Chronic intraparenchymal hemorrhage is characterized by marked hyperintensity both centrally and peripherally on both T1 and T2 weighted images and by marked hypointensity of the adjacent brain rim on T2 weighted images owing to hemosiderin deposition. Surrounding edema is no longer present. 7. The integrity of the blood-brain barrier appears to be important in determining whether or not hemosiderin accumulations consistently occur in subacute and chronic hemorrhage. 8. Hemorrhagic conditions in which the defined sequence of signal intensity patterns may be seen include: venous thrombosis, hemorrhagic infarction, occult vascular malformation and intracranial aneurysm.     

Sex-dependent organ distribution of radiopharmaceuticals: effect of hormones on localization of acetyl-103Ru-ruthenocene

This paper demonstrates modification of organ distribution of a radiopharmaceutical, acetyl-103Ru-ruthenocene, by competing drugs. This radiopharmaceutical concentrates in kidneys of male Wistar rats 15-fold higher than in females of the same strain and age. This concentration in the male is age-dependent. Moreover, the retention of that radiopharmaceutical in male rats' kidneys is markedly reduced by pre-treatment of the rats with estradiol, and this effect is dose-dependent. Estradiol is competetively inhibiting the retention of acetyl-ruthenocene by the kidneys, the same effect also being obtained by tamoxifen, an anti-estrogen used clinically for regression of mammary carcinoma. Blocking the retention of acetyl-ruthenocene was also obtained by testosterone and cyproterone-acetate, as well as by ovariectomy, but the block after castration was partially compensated with time. Blood clearance of acetyl-ruthenocene is biphasic, with a first t 1/2 of about 12 h, and a second t 1/2 of about 48 h. The retention of the label is sex-specific also in mice, but only the female mice show a high adrenal affinity and significant changes in its organ distribution. These effects may be due to competition of acetyl-ruthenocene for steroid receptors, or due to its activation of enzymes that are responsible for its transformation into a bindable moiety.     

Analysis of the acetabulum anterior cover

PURPOSE: The false profile X-Ray view as described by Lequesne, allowing the measurement of the anterior cover of the acetabulum, is a slantwise view obtained by a 65 degrees inclination of the pelvis on the radiographic plate.The errors introduced by this radiological measurement of the anterior cover are evaluated. MATERIALS AND METHODS: An anatomical and radiological analysis is conducted on 20 acetabula. The anterior cover is measured on the bone and the A point, the anterior extremity of the acetabular roof, is plumbed. Each pelvis is imaged following the Lequesne method. The VCA angle is measured with the radiological point A described by Lequesne and with the metallic point A as reference. RESULTS: The difference between the anatomical and radiological values of the anterior cover is an average by 11 degrees and undervalues the anatomical value. The deviation is reduced by the application of a trigonometrical formula. A difference between the radiological localisation of A point described by Lequesne and the metallic marker is pointed out. This difference increases when the acetabulum becomes dysplasic. CONCLUSION: The acetabular anterior cover measured with the radiological incidence described by Lequesne undervalues the real value. Moreover, the error increases when the acetabulum is dysplasic.     

Measurement of rat brain perfusion by NMR using spin labeling of arterial water: In vivo determination of the degree of spin labeling

In vivo NMR experiments are performed to determine the degree of spin labeling for measurement of tissue perfusion by NMR using spin labeling of arterial water by adiabatic fast passage. Arterial water spins are labeled using flow in the presence of a field gradient and B₁ irradiation to fulfill the conditions for adiabatic fast passage spin inversion. It is demonstrated that the NMR-measured tissue perfusion is not affected by changing the degree of spin labeling as long as the degree of spin labeling is determined and accounted for according to the model used for calculating perfusion. By measuring the degree of spin labeling with different arterial blood flow velocities induced by different arterial pCO₂, it is also demonstrated that, when spin labeling is carried out by adiabatic fast passage, the degree of spin labeling is not affected by changes in arterial blood flow velocity over a broad range.     

The conscious perception of the sensation of fatigue

In this review, fatigue is described as a conscious sensation rather than a physiological occurrence. We suggest that the sensation of fatigue is the conscious awareness of changes in subconscious homeostatic control systems, and is derived from a temporal difference between subconscious representations of these homeostatic control systems in neural networks that are induced by changes in the level of activity. These mismatches are perceived by consciousness-producing structures in the brain as the sensation of fatigue. In this model, fatigue is a complex emotion affected by factors such as motivation and drive, other emotions such as anger and fear, and memory of prior activity. It is not clear whether the origin of the conscious sensation of fatigue is associated with particular localised brain structures, or is the result of electrophysiological synchronisation of entire brain activity.     

SARS抗病毒治疗的药物选择探讨

目的　分析不同SARS抗病毒治疗方法的效果 ,为制定SARS抗病毒治疗方案提供参考。方法　采用临床流行病学回顾研究 ,使用SPSS11.0软件分析我院SARS患者的住院病历 ,分析选择不同抗病毒治疗药物治疗SARS的T细胞亚群、血象、肝肾功能变化及临床效果。结果　本文研究发现 ,利巴韦林治疗病死率为 18.0 3% ;干扰素组T细胞亚群下降值最低 ,但治愈率为 10 0 % ,与利巴韦林组比较 (P <0 .0 0 1)统计学有极显著性差异 ,并有延长T细胞亚群下降至最低值时间的趋势 (P >0 .0 5 ) ;干扰素与利巴韦林联合治疗可延长T细胞亚群下降至最低值的时间 ,CD3 与利巴韦林组比较 (P <0 .0 5 )统计学有显著性差异 ,病死率为 6 .0 6 % ,与利巴韦林组比较 (P <0 .0 5 )统计学有显著性差异 ,并低于文献报道水平 (6 .5 % )。干扰素组对SARS患者血象及肝肾功能的影响最小 ,各组与利巴韦林组比较 (P >0 .0 5 )统计学无显著性差异。结论　干扰素或干扰素联合利巴韦林抗病毒治疗效果优于单独使用利巴韦林的效果。干扰素抗病毒治疗效果最好。     

Radiologic diagnosis of pneumoconioses

Radiology is extremely important in the diagnosis of occupational lung disease. Owing to its general availability and international comparability, the roentgenographic pa view of the chest obtained by the high-voltage technique is still the basis of the radiologic examination. Supplementary investigations are necessary for medical reasons, however, as well as for documentation of experts' certification. Valuable diagnostic information is supplied by oblique views of the thorax and by conventional X-ray tomography, though not by scintigraphic examinations or - up to now - by digital luminescence radiography. Ultrasound helps in the differentiation of free pleural fluid, organized pleural effusion, and pleural malignancy. In addition, computed tomography (CT) can be guided by ultrasound. CT has emerged as the method of choice for examination and for support of medical experts' certification of pneumoconiotic pleural disease, and high-resolution CT (HRCT) is also increasing used for examination of pneumoconiotic lung foci as well. Diagnostic accuracy in pneumoconiosis is further improved by shorter CT scanning times in combination with HRCT.     

Influence of Apoptosis on the Enhancement of Radiotoxocity by Ouabain

BACKGROUND: The Na+, K(+)-ATPase inhibitor ouabain enhances the toxicity of irradiation and we have previously demonstrated that the drug suppresses repair capacity. The influence of ouabain on apoptosis is not known and is examined in this study. MATERIALS AND METHODS: Seven human cell lines of defined TP53 status were irradiated with 60Co-gamma irradiation in the presence and absence of 10(-7) M ouabain. Cell survival was determined by the clonogenic assay, apoptosis by acridine orange staining and cell cycle delays by flow cytometry. RESULTS: The ouabain-induced enhancement of radiotoxicity, expressed as the ratio of SF2's, is independent of TP53 status and ranges from 1.1 to 2.8 depending upon cell line. Ouabain prolongs the irradiation-induced G2 delay in TP53 mutant tumor cell lines by a factor greater than 2, but not in the normal lung fibroblast L132, where the cell recovery is not altered in the presence of ouabain. Twenty hours post irradiation, ouabain enhances apoptosis induced by irradiation by factors of 1.3 to 1.7 depending on the cell line. CONCLUSION: Ouabain preferentially enhances the radiotoxicity in tumor cells irrespective of TP53 status. In the pattern of DNA damage responses which are influenced by ouabain we show that the G2 cell cycle delay is prolonged and that early apoptosis events are upregulated in TP53 wild type and TP53 mutant cells. It is concluded that apoptosis plays a significant role in the enhancement of radiotoxicity by ouabain.     

Mechanisms of cell reproductive death and shapes of radiation dose--survival curves of mammalian cells

A 'paired dsb' mechanism of action for cell reproductive death by ionizing radiations is proposed, which allows interpretation of differences in shapes of survival curves caused by variation of linear energy transfer of the radiation, by the stage in the cell cycle, but cell culture conditions and by sensitizing and protecting compounds. It is based on the analysis of shapes of survival curves in terms of S(D)/S(O) = exp - (a1D + a2D2) and the suggestion that paired dsb in DNA, produced within distances of the order of 10 nm, are efficient in initiating the sequence of events causing cell reproductive death by individual particle tracks. Part of the lethality may result from two dsb's produced by single tracks at larger distances, and this might constitute potentially lethal damage which in favourable conditions can be repaired. Thus, the initial slope of a survival curve is not independent of the repair capacity of a cell, but indeed can be modified by cell conditions. The damage causing the quadratic term in the survival equation may be interpreted as a consequence of two dsb produced by two different ionizing particles, although other interactions cannot be excluded. The suggested mechanism of 'paired dsb' damage is consistent with information concerning the LET dependence of different effects in cells and their constituents.     

Massive recurrent epistaxis in traumatic pseudoaneurysm of sphenopalatine artery: Report of 2 cases

Massive recurrent epistaxis because of traumatic pseudoaneurysm of the sphenopalatine artery is rarely diagnosed. It is formed by partial rupture of the endothelium by facial trauma and managed with embolization and maxillofacial reconstruction. Here, we report a case of 2 massive recurrent epistaxes and 1 case of carotid cavernous fistula, which needed embolization to control the recurrent bleeding following trauma. Epistaxis is first managed by tampon, then referred as needed for endovascular intervention by sphenopalatine artery embolization and followed by maxillofacial reconstruction. Recurrent epistaxis was successfully treated with endovascular embolization.     

Polysplenia with duplication of the inferior vena cava. Apropos of a case

A case of polysplenia fortuitously discovered in an adult by sonography, then studied by computed tomography and inferior vena cavography, is reported. In the absence of cardiac anomalies, the different elements of the syndrome are discussed: multiple spleens, abdominal heterotaxia and vascular malformations. The duplication of the inferior vena cava is exceptional in this disease. Its original characteristic is shown by the cavography and brought to its embryologic origin.     

Mechanisms of Cell Reproductive Death and Shapes of Radiation Dose-survival Curves of Mammalian Cells

Summary

A ‘paired dsb’ mechanism of action for cell reproductive death by ionizing radiations is proposed, which allows interpretation of differences in shapes of survival curves caused by variation of linear energy transfer of the radiation, by the stage in the cell cycle, by cell culture conditions and by sensitizing and protecting compounds. It is based on the analysis of shapes of survival curves in terms of S(D)/S(0) = exp ? (a₁D + a₂D²) and the suggestion that paired dsb in DNA, produced within distances of the order of 10 nm, are efficient in initiating the sequence of events causing cell reproductive death by individual particle tracks. Part of the lethality may result from two dsb's produced by single tracks at larger distances, and this might constitute potentially lethal damage which in favourable conditions can be repaired. Thus, the initial slope of a survival curve is not independent of the repair capacity of a cell, but indeed can be modified by cell conditions. The damage causing the quadratic term in the survival equation may be interpreted as a consequence of two dsb produced by two different ionizing particles, although other interactions cannot be excluded. The suggested mechanism of ‘paired dsb’ damage is consistent with information concerning the LET dependence of different effects in cells and their constituents.     

Study of tuberculous meningitis by CT

Summary Computed tomography is a very valuable method by which the pathogenic evolution of tuberculous meningitis may be followed, thereby facilitating its differential diagnosis and controlling the efficiency of therapy. The initial miliary tuberculosis in the brain, very often unaccompanied by neurological symptoms, may offer very evident CT images. CT may also demonstrate the fibrogelatinous exudate which fills the basal cisterns and surrounds the arterial vessels which cross this region. Because of this, secondary arteritis is frequent and may be indirectly detected by CT in the form of foci of ischemic infarcts. Tuberculomas may be multiple, and are found equally in the cerebral and the cerebellar parenchyma. These tuberculomas present different images on CT, depending on the evolution of the disease at that moment. Hydrocephalus is a common complication of TM and is caused by a lack of reabsorption of the cerebrospinal fluid, or by an obstructive lesion in the ventricular drainage pathways due to a tuberculoma. This complication is usually easily identified by CT, which, moreover, permits the control of its evolution.     

Molecular mechanism of cell death by radiation

p53 protein, a tumor suppressor protein, is accumulated and activated by ionizing radiation. It activates various downstream genes whose functions are involved in cell cycle arrest, apoptosis, and DNA repair. Although it was thought generally that G1 arrest by p53 activation after ionizing radiation was a transient phenomenon to facilitate DNA repair, we found that it is irreversible and permanent in both normal human cells and tumor cells. Because cells arrested irreversibly express various phenotypes, such as cell enlargement and expression of senescence associated-beta-gal, this is related to cellular senescence, but not to apoptosis. Therefore, we termed this phenomenon senescence-like growth arrest (SLGA). These results indicate that SLGA is the main form of cell death caused by ionizing radiation. SLGA can be utilized as an index of cancer therapy, because it is induced not only by radiation but also by anticancer drugs and is easy to examine by vital staining, thereby making the induction of SA-beta-gal an index.     

Development of stereotactic irradiation system of body tumors under respiratory gating

Stereotactic radiosurgery for body tumors is hampered by the difficulties in body fixation and respiratory motions of the tumor. We have developed a Microton-based system for the stereotactic irradiation of body tumors, which delivers radiation at a predetermined respiratory phase. The patients are fixed non-invasively in the custom-made bed, and CT images are obtained. The isocentor is calculated with reference to those images and is marked onto the patient's skin and the custom-made bed. The patient lying on the bed is transferred to the treatment couch of the Microtoron. After reproducing the isocenter, actual treatment is started. The treatment couch as well as the gantry move automatically around the isocenter according to the treatment planning. The circular collimator moves by computer control to reduce geometrical errors to less than 0.5 mm, which is evoked by gantry movement. Respiratory movement of the abdominal wall is measured by laser displacement monitor. The Microtron delivers X-rays at a predetermined respiratory phase with a lag time of 20 msec after the on-signal from the monitor.     

Imaging phenotypes of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide. COPD is defined by irreversible airflow obstruction. It is a heterogeneous disease affecting the airways and/or the parenchyma with different severity during the course of the disease. These different aspects of COPD can be addressed by imaging using a combination of morphological and functional techniques. Computed tomography (CT) is the technique of choice for morphological imaging of the lung parenchyma and airways. This morphological information is to be accomplished by functional information about ventilation and perfusion, mainly provided by magnetic resonance imaging (MRI). The comprehensive diagnostic possibilities of CT complemented by MRI will allow for a more sensitive detection, phenotype-driven characterization, and dedicated therapy monitoring of the disease.     

B超对表浅淋巴结肿大的诊断价值(附77例分析)

目的 :探讨B超对表浅淋巴结肿大的诊断价值及临床意义。方法 :对临床确诊的 38例癌肿及 39例炎性感染所引起表浅淋巴结肿大者行B超检查。结果 :发现癌性淋巴结肿大 ,其形态趋向于圆形或偏心呈水滴状 ,内部回声类似囊肿或回声不均质。炎性淋巴结肿大 ,其形态仍呈椭圆形 ,周围呈低回声 ,中央呈强回声。结论 :B超能对浅表淋巴结肿大作出准确判断 ,对肿瘤治疗方案的制定提供客观资料     

The role of calcium in the energetics of contracting skeletal muscle.

In its second messenger role in skeletal muscle, calcium coordinates the function of muscle (contractile activity) with its overall energetics, thereby controlling the provision of ATP in a time of need. Not only is ATP required for crossbridge turnover in the myofibrils, but it is also needed for the maintenance of ion pumps, nuclear activity, and so forth. When oxygen is limiting, the sustained contractions of both fast and slow muscle (after the immediate burst of activity) is primarily supported by glycogenolysis and the glycolytic pathway (anaerobic). Calcium is important to this process, and the compartmentation of the glycogen particle and some of the enzymes associated with the glycolytic pathway in the terminal cisternae of the sarcoplasmic reticulum ensures that the provision of glucose-6-phosphate to the glycolytic pathway for the generation of the needed ATP proceeds rapidly. The activation of phosphorylase and glycogenolysis by calcium-troponin-C is another example of the tight control of cellular energetics deemed possible by compartmentation within the cell. The regulation by calcium, therefore, is only dependent on the diffusion of calcium rather than diffusion of substrate. When oxygen is not limiting (i.e. when a new steady-state is reached), the aerobic metabolism of pyruvate and fatty acids may be regulated in part by calcium at least in slow skeletal muscle. Oxidative phosphorylation, where ADP is phosphorylated to ATP, is though to be controlled by the concentration of ADP in skeletal muscle. However, because of the obvious compartmentation of the mitochondria within the slow muscle fibre and the higher free calcium required for peak force development (5 mumol/L), the kinetics are theoretically favourable for the calcium cycle in slow muscle mitochondria to play an important role in the regulation of aerobic substrate oxidation, as it does in the heart. Although this hypothesis is attractive based on the available data, the direct demonstration of a major role for calcium as a regulator of substrate oxidation in slow muscle awaits experimentation.