雷公藤内酯对人胃癌细胞株FGC_(85)杀伤作用的光镜和电镜观察

本文应用核苷掺入技术及电镜观察首次证实雷公藤内酯对人胃癌细胞株 FGC_(85)的杀伤作用。用药早期,细胞数,分裂指数及 DNA,RNA 合成无明显变化,但出现核仁脱粒及核仁破碎等变化;晚期,电镜观察发现细胞以凋落方式死亡,药物主要作用于间期细胞,其杀伤机构的始动环节可能与核酸代谢障碍无关。     

妊娠期妇女的人体测量及脂肪贮存

本文对30名居住北京城近郊区的健康初产孕妇,于妊娠早期、中期及末期连续进行人体测量,包括身长,体重,皮下脂肪厚度和肢体围,以观察孕期体重增长,身体脂肪含量及肌肉情况。测量结果,受试者从妊娠6周至37周平均体重增长13.0kg。三头肌、二头肌部位皮脂厚度在孕期无明显变化。肩胛下皮脂厚度至孕末期时明显较早期增加。髂骨上皮脂厚度在孕中期及末期均有明显增长,与早期相比差別显著。据皮脂厚度计算身体密度及脂肪含量络果,至孕末期身体脂肪含量占体重的百分比共增加3.7％。肢体围测量结果,仅臀围在妊娠中期后至末期明显较早期增大。大腿上部围略有增加,但与早期差别无显著意义。大腿中部、小腿腓肠肌部及上臂围孕期均无明显变化。     

Osteoporosis and Coronary Atherosclerosis in Asymptomatic Postmenopausal Women

Estrogen deficiency is a risk factor for osteoporosis and coronary artery disease. Osteoporosis can be evaluated by measuring bone mineral density (BMD). Coronary atherosclerotic burden can be evaluated by measuring coronary calcium using electron beam computed tomography (EBT) of the heart. We compared coronary calcium scores in 45 asymptomatic postmenopausal women with normal and low BMD. BMD of the lumbar spine and proximal femur was measured by dual X-ray absorptiometry (DXA), and coronary calcium was measured quantitatively by EBT. Women were divided into control, osteopenia, and osteoporosis groups based on the T score of the lumbar spine. Women were similar in age, years since menopause, height, weight, and body mass index (BMI). BMD ± SD (g/cm²) of L1–L4 was 0.96 ± 0.11, 0.83 ± 0.03, and 0.73 ± 0.05, in control, osteopenia, and osteoporosis group, respectively. The total coronary calcium score ± SD (relative units) was 41.9 ± 83.1, 115.1 ± 181.9, and 221.7 ± 355.4 for control, osteopenia, and osteoporosis group, respectively; the score was significantly higher in the osteoporosis than in the control group. This study provides initial data suggesting that women with osteoporosis may have a higher risk of developing coronary atherosclerosis.     

Peritoneal morphology in children treated by continuous ambulatory peritoneal dialysis

Fifty peritoneal biopsies (PB) from 35 patients with end-stage renal disease, treated by continuous ambulatory peritoneal dialysis (CAPD) and aged 2 months to 18 years, were examined by light microscopy (n=50) and/or scanning electron microscopy. PB were performed during surgical procedures immediately before the start of, during, or after the cessation of CAPD treatment. PB from 15 children without renal disease undergoing laparatomy were examined similarly. Before the start of CAPD, a scarcity and shortening of the mesothelial microvilli was observed by scanning electron microscopy. During and after CAPD, variable alterations of mesothelium, interstitium and capillaries were found. The mesothelial layer was absent in all 5 PB obtained during episodes of active peritonitis. In patients treated by CAPD for longer than 6 months, mesothelial denudation was observed more frequently (6/11) than in children treated for shorter periods (1/7) (P<0.08). Fibrosis of the peritoneal membrane was present in about 50% of patients during or after the cessation of CAPD without impairment of peritoneal function. No correlation was found between the presence of fibrosis and the frequency of peritonitis or the duration of CAPD treatment.     

人乳头瘤病毒感染超微结构观察

本文对5例典型尖锐湿疣标本及10例可疑人乳头瘤病毒感染标本进行透射电子显微镜观察。结果典型尖锐湿疣标本中仅1例于细胞核内见到人乳头瘤病毒,排列规则呈结晶状。其余14例标本的细胞内均见不同程度的由病毒感染所引起的非特异性病理变化。本文对人孔头瘤病毒及受感染细胞的超微结构进行了初步探讨。     

Na+ currents near and away from endplates on human fast and slow twitch muscle fibers

Fast and slow twitch muscle fibers have distinct contractile properties. Here we determined that membrane excitability also varies with fiber type. Na⁺ currents (I_NA) were studied with the loose-patch voltage clamp technique on 29 histochemically classified human intercostal skeletal muscle fibers at the endplate border and <200 μm from the endplate (extrajunctional). Fast and slow twitch fibers showed slow inactivation of endplate border and extrajunctional I_NA and had increased I_NA at the endplate border compared to extrajunctional membrane. The voltage dependencies of I_NA were similar on the endplate border and extrajunctional membrane, which suggests thatboth regions have physiclogically similar channels. Fast twitch fibers had larger I_NA on the endplate border and extrajunctional membrane and manifest fast and slow inactivation of I_NA at more negative potentials than slow twitch fibers. For normal muscle, the differences between I_NA on fast and slow twitch fibers might: (1) enable fast twitch fibers to operate at high firing frequencies for brief periods; and (2) enable slow twitch fibers to operate at low firing frequencies for prolonged times. Disorders of skeletal membrane excitability, such as the periodic paralyses and myotonias, may impact fast and slow twitch fibers differently due to the distinctive Na⁺ channel properties of each fiber type. © 1993 John Wiley & Sons, Inc.     

Precision of dual-photon absorptiometry

Summary Precision of dual-photon absorptiometry (DPA) measurements was determined in a lumbar spine phantom and in humans. Approximately half of the measurements were made before and half after a¹⁵³gadolinium source change. The phantom was measured with different amounts of acrylic, which simulates human soft tissue, in order to evaluate the influence of body thickness on bone mineral density (BMD). Results of scans analyzed with two software versions from Lunar Radiation Corp., the widely used 08B and a prototype 08C, are compared. DPA with a cold source significantly overestimated BMD in the phantom in the presence of large amounts (more than 25 cm) of soft tissue equivalent with version 08B but not with the newer version 08C. Similiarly, in nine subjects, there was a significant decrease in spine BMD after a source change when scans were analyzed with version 08B (mean difference 0.026 g/cm²,P=0.002) but not with 08C (0.01 g/cm²,P=0.234). No systematic effect of source change on femoral BMD measurements was observed. The SD of the mean difference of two measurements of the nine subjects was 0.019 g/cm² (1.6% of the mean value) for the spine with software version 08B and 0.024 g/cm² (2.0%) with version 08C, 0.03 g/cm² (3.3%) for the femur neck, 0.03 g/cm² (4.0%) for the greater trochanter, and 0.04 g/cm² (4.9%) for Ward's triangle region of the proximal femur. The spine phanton was scanned on two other commercial bone densitometers in order to assess inter-instrument variation. Phantom measurements of L2-4 BMD made on two Lunar Radiation Corp model DP3 scanners which differed by 2% were 10 and 12% higher than those with a Norland Corp. model 2600 scanner.     

Ultrastructural distribution of NADPH-diaphorase in the normal hippocampus and after long-term potentiation

Summary The distribution of the enzyme nitric oxide synthase (NOS) was investigated at the ultrastructural level in synaptic structures of the hippocampal formation in relation to long-term potentiation (LTP), based on the histochemical NADPH-diaphorase (NADPH-d) staining with the tetrazolium salt BSPT. BSPT-formazan, the osmiophilic reaction product, was found to be selectively distributed and predominantly attached to membranes of the endoplasmic reticulum. In synaptic regions mainly the presynaptic sides showed labeling. Although several groups have demonstrated a principal involvement of NO in the LTP-mechanism, we found only a low, statistically insignificant increase in NADPH-d stained presynaptic areas of the dentate gyrus, where LTP was evoked. Postsynaptic elements also did not show any noticeable differences. Based on the present results, the predominantly presynaptic localization of NOS should be preferably considered in models describing a functional role of NO in LTP formation, despite the fact that we failed to reveal any indications for an LTP-related change in synaptically located NADPH-d.     

ONCOCYTES OF THE THYROID: A NEUTRAL RED DYE UPTAKE STUDY

Oncocytosis and oncocytomas have attracted attention because on the one hand there have been reports of the favourable prognosis and generally benign nature of oncocytic tumours, while on the other hand, Hurthle cell change in thyroid neoplasms have been reported to be correlated with aggressive biological behaviour and a significantly worse clinical course. Presently, there appear to be two schools of thought on the significance of oncocytosis: (i) a process where there is redifferentiation of cells with involvement in the pathogenesis of cancer; and (ii) a compensatory process for ‘functional exhaustion’ of the cell. Many aspects of oncocytosis seem unclear. In this study, transmission electron microscopy is used to demonstrate the presence of thyroid oncocytes in the hemithyroidectomy specimen of a patient with focal lymphocytic thyroiditis. Tissue sections from this specimen did not display preferential uptake of neutral red dye, a distinctive characteristic of M-phase cancer cells which was previously reported. The findings seem to suggest that oncocytes are not cells with distinctive proliferative potentials. If that were the case, then oncogenesis or cancer cell progression and oncocytosis may not be convergent processes.