Scanning electron microscopy最新文献_第5页

Freeze-dried embedded specimens for biological microanalysis. 冻干包埋标本用于生物微量分析。

Scanning electron microscopy Pub Date : 1986-01-01

L Edelmann

{"title":"Freeze-dried embedded specimens for biological microanalysis.","authors":"L Edelmann","doi":"","DOIUrl":"","url":null,"abstract":"The main problems associated with freeze-drying of biological material for electron microscopy concern the freeze-drying temperatures and times necessary to minimize artifacts. Due to the many parameters involved these problems have to be resolved experimentally. It can be shown that good morphological preservation of chemically unfixed material is possible when freeze-drying is done exclusively in a temperature range between -80 degrees C and -50 degrees C. OsO4 vapour fixation of the freeze-dried tissue is not necessary and should be avoided because it may cause ion redistribution artifacts. Embedding at low temperature of properly freeze-dried material does not seem to disturb structure and ion distribution of the freeze-dried material. Hence, sections of such freeze-dried material and embedded biological material seem to be suitable for microanalysis. Preliminary micro-analytical results obtained from sections of freeze-dried and Lowicryl K11M embedded muscle reveal an uneven distribution of potassium in the sarcomeres similar to the visualized uneven distribution of the electron dense thallium (potassium surrogate) in frozen hydrated cryosections. A comparison of different cryomethods shows that freeze-drying and embedding is the simplest way to obtain stable thin sections of chemically unfixed biological material which, for instance, may be used for future microanalytical investigation of the interaction of proteins with physiological and non-physiological ions.","PeriodicalId":21455,"journal":{"name":"Scanning electron microscopy","volume":" Pt 4","pages":"1337-56"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14666650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Lipofuscin accumulation in cultured non-dividing cells as a function of time and oxygen tension. 非分裂细胞中脂褐素积累随时间和氧张力的变化。

Scanning electron microscopy Pub Date : 1986-01-01

A Brunmark, V P Collins, H Thaw, U Brunk

{"title":"Lipofuscin accumulation in cultured non-dividing cells as a function of time and oxygen tension.","authors":"A Brunmark, V P Collins, H Thaw, U Brunk","doi":"","DOIUrl":"","url":null,"abstract":"Cultivated human glial cells, kept in a state of density-dependent inhibition of growth, accumulate age-pigment (lipofuscin) within their lysosomal vacuomes with the same characteristics as the corresponding pigment observed in vivo. The rate of formation and accumulation of lipofuscin is greatly accelerated under the conditions of routine cell cultivation in comparison to the in vivo event. Lipofuscin is generally considered to be composed of polymerized products of lipid peroxidation and thus it would be reasonable to suggest that factors which influence lipid peroxidation would also alter the rate of lipofuscin formation. Human glial cells were grown in the presence of various oxygen concentrations in the gas-phase (5%, 10%, 20%, 40%). This was found to modulate (accelerate or decrease) the rate of lipofuscin formation. The present study thus provides: important supportive evidence for the lipid peroxidation origin of lipofuscin, a useful model system for studying the effect of lipofuscin accumulation on lysosomal function and cell growth kinetics, evidence that our standard culture conditions are far from ideal since oxygen concentration may drastically alter rates of lipofuscin formation and accumulation. Cell culture technique, as we know it today, may benefit from more closely controlled oxygen tensions, i.e., by reducing oxygen to levels that more closely approximate conditions in vivo.","PeriodicalId":21455,"journal":{"name":"Scanning electron microscopy","volume":" Pt 1","pages":"189-92"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14856504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microcorrosion casting of the human respiratory acinus. 人体呼吸腺的微腐蚀铸造。

Scanning electron microscopy Pub Date : 1986-01-01

S A Dilly

{"title":"Microcorrosion casting of the human respiratory acinus.","authors":"S A Dilly","doi":"","DOIUrl":"","url":null,"abstract":"Microcorrosion casts demonstrating the respiratory acini of human lungs were produced using Tensol Cement No. 70 (a methyl methacrylate mixture). Lung casts were made from foetuses of 19 weeks' gestation to term, a child of 5 years and two adults. Tensol Cement No. 70 was found to infuse the most peripheral airspaces without tissue penetration and could be airdried. Attempts using Batson's medium were hampered by permeation of the airway walls and inability to withstand airdrying. Despite the use of autopsy material, good cell impressions were seen. At 19 weeks' gestation, the respiratory acinus is simple with only two or three generations of rather tubular respiratory bronchioles. In later intra-uterine development, the number of generations of intra-acinar airways increases and the most peripheral airspaces expand to form initially shallow but later cup-shaped saccules. At all ages, the proximal airways of the acinus have regularly-spaced deep cell impressions suggesting a cuboidal/columnar epithelium while the distal airspaces have less frequent shallow cell impressions suggesting a flattened epithelium. Measurements of the maximum diameter of the most peripheral airspaces show an approximate doubling of size between 19 weeks' gestation and term and a further doubling by the age of 5 years.","PeriodicalId":21455,"journal":{"name":"Scanning electron microscopy","volume":" Pt 3","pages":"1095-101"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14915007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ultrasonic microdissection of immature intermediate human placental villi as studied by scanning electron microscopy. 扫描电镜研究了未成熟中间人胎盘绒毛的超声显微解剖。

Scanning electron microscopy Pub Date : 1986-01-01

G J Highison, F D Tibbitts

{"title":"Ultrasonic microdissection of immature intermediate human placental villi as studied by scanning electron microscopy.","authors":"G J Highison, F D Tibbitts","doi":"","DOIUrl":"","url":null,"abstract":"The human placenta during the first 20 weeks of gestation undergoes rapid and extensive morphological changes. Near the end of this period, the most predominant type of villus present is the immature intermediate placental villus. In order to visualize this complex structure with scanning electron microscopy (SEM), we have developed a microdissection technique to expose tissue components of the placental villus while retaining its normal histological architecture. Placental villi were initially fixed in Karnovsky's fixative, buffered formalin, or 2% osmium tetroxide solution prior to exposure to connective tissue enzymes or detergents alone or in combination. Samples were dehydrated through 100% acetone and ultrasonicated at 80 kHz for 15 minutes prior to critical point drying and SEM examination. The most satisfactory microdissections were obtained by using a combined detergent/ultrasonication technique. By means of this procedure it was possible to remove the syncytiotrophoblast to expose the underlying cytotrophoblast, basal lamina and the stromal core components of the villi. The selective removal of these structures revealed the 3-dimensional relationships of the stromal channels, reticulum cells and Hofbauer cells. Of interest was the pattern of fetal capillaries coursing parallel to the long axis of each villus and terminating in a vascular knot at the tip.","PeriodicalId":21455,"journal":{"name":"Scanning electron microscopy","volume":" Pt 2","pages":"679-85"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14917031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The microvascular architecture of the vestibule and the endolymphatic duct and sac of the rat in vascular corrosion casts. 血管腐蚀铸型中大鼠前庭及内淋巴管和囊的微血管结构。

Scanning electron microscopy Pub Date : 1986-01-01

T Ohmichi, R Saito, K Matsubara, K Terazawa, S Tasaka, Y Ogura

引用次数: 0

Analysis of canine urinary stones using infrared spectroscopy and scanning electron microscopy. 犬尿路结石的红外光谱及扫描电镜分析。

Scanning electron microscopy Pub Date : 1986-01-01

A Hesse, G Sanders, D B Leusmann

引用次数: 0

Scanning electron microscopy of the irradiated mouse bladder urothelium. 照射后小鼠膀胱尿路上皮的扫描电镜。

Scanning electron microscopy Pub Date : 1986-01-01

J B Reitan, K Feren

引用次数: 0

Crystalluria and urolithiasis in a relatively stone-free population. 相对无结石人群中的结晶尿症和尿石症。

Scanning electron microscopy Pub Date : 1986-01-01

A L Rodgers, D P De Klerk

{"title":"Crystalluria and urolithiasis in a relatively stone-free population.","authors":"A L Rodgers, D P De Klerk","doi":"","DOIUrl":"","url":null,"abstract":"The occurrence of renal stone in South African blacks is extremely rare. Whites however are prone to calculi to the same extent as that reported in other Western communities. The nature of the particulate material and crystalluria in urine samples from the two population groups were investigated using a Coulter Counter and scanning electron microscope. In addition, 10 calculi obtained from black patients over a 5 year period were analysed. The particle size distribution curves obtained for normal black and white males were identical. The curves for normal black and white females were also identical but different from those for males. Black male stone formers had larger particles than their controls while the single black female stone former investigated had particles of the same size as female controls, but in greater numbers. Scanning electron microscopy revealed profuse amounts of crystalline NaCl, KCl and other salts in the urinary sediments of blacks. These were not observed in the specimens from whites nor in the black stone formers' urines. Analysis of the calculi identified chemical and ultrastructural features similar to those observed in stones from whites. The hypothesis that the lower incidence of stone disease in blacks may be due to a high Na/Ca ratio is supported by our findings. It is suggested that various salts play a role in lowering the stone forming potential of such urines by a competitive substitution mechanism in which lattice calcium is displaced by sodium. It is also suggested that when urinary stone formation does occur in blacks, it does so via the same physicochemical mechanisms as in any other race group.","PeriodicalId":21455,"journal":{"name":"Scanning electron microscopy","volume":" Pt 3","pages":"1157-67"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14915835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Struvite crystalluria and urolithiasis in cross Labradors. 拉布拉多犬的鸟粪石结晶性尿症和尿石症。

Scanning electron microscopy Pub Date : 1986-01-01

A L Rodgers, R A Irving, M Mezzabotta, P Benloulou

{"title":"Struvite crystalluria and urolithiasis in cross Labradors.","authors":"A L Rodgers, R A Irving, M Mezzabotta, P Benloulou","doi":"","DOIUrl":"","url":null,"abstract":"Recurrent struvite crystalluria and urolithiasis in a cross-Labrador bitch was studied using a combined Coulter-Counter and scanning electron microscope (SEM) approach. Staphylococcus bacteria were cultured from the patient's urine as well as from the calculi themselves. Urine samples were subjected to particle counting and sizing during active and non-active periods of stone formation. Size distribution curves so obtained were identical as were those derived from sterile and non-sterile specimens. These showed a peak incidence at a diameter of 5 microns. Particle sizes for 6 controls were also determined and showed an even distribution over a much wider range with small peaks occurring at 3, 10, and 20 microns diameters. SEM studies of urine sediments revealed the presence of struvite crystals in all the controls as well as in the stone-former. These occurred in a variety of shapes and sizes but were generally larger in the controls. SEM also revealed intimate admixtures of struvite and apatite in calculi surgically removed from the patient. The results of this study indicate that crystal numbers are of greater significance than crystal size. It is also suggested that Cross-Labradors may be unusually predisposed to struvite crystalluria. The repeated recurrence of struvite urolithiasis in the subject indicates a possible inherent physiological malfunction in the animal's ability to cope with this crystalluria. The absence of a nucleation inhibitor in the stone-former's urine is also postulated.","PeriodicalId":21455,"journal":{"name":"Scanning electron microscopy","volume":" Pt 3","pages":"1169-74"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14915836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Embryonic development of the chicken external cloaca and phallus. 鸡外泄殖腔和阴茎的胚胎发育。

Scanning electron microscopy Pub Date : 1986-01-01

M R Bakst

{"title":"Embryonic development of the chicken external cloaca and phallus.","authors":"M R Bakst","doi":"","DOIUrl":"","url":null,"abstract":"The use of the scanning electron microscope has provided new detailed information about the embryonic development of the chicken external cloaca and phallus and has consequently clarified the origin of the differences between the anatomy of the chicken and turkey phallus. At Day 6 (of incubation), the genital (g.) tubercle is formed in the ventral aspect of the embryo between the caudal fold of the amnion and the tail bud. On the ventral surface of the tail bud are paired g. swellings which flank the g. tubercle. Originating at the midline between the g. swellings is the g. crest which is joined cranially to the g. tubercle and later in development forms the ventral floor of the proctodeum (the most caudal cloacal compartment). By Day 8 the base of the g. tubercle has expanded caudolaterally to merge with the craniolateral extensions of the g. swellings. The g. swellings have likewise merged medially thus completing a collar-like structure around the g. tubercle. By Day 16, the dorsal and ventral lips of the cloaca have differentiated from the collar-like structure and the rounded, apical region of the g. tubercle gives rise to the primitive phallus. Further development of the external cloaca and phallus is limited primarily to the rotation of the phallus toward the ventral floor of the proctodeum and the concurrent shortening (longitudinally) of the proctodeum. Additional differentiation of the phallus occurs after hatching.","PeriodicalId":21455,"journal":{"name":"Scanning electron microscopy","volume":" Pt 2","pages":"653-9"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14917028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0