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PubMed1987

Myocardial protection: left ventricular ultrastructure after different forms of cardiac arrest.

Clinically applied methods of cardioplegia show very different effects on the rapidity of decay of energy-rich phosphates as well as on kind and progression of ultrastructural alterations of the ischemic myocardium. Comparing the methods of cardioplegia according to Kirklin, St. Thomas's Hospital and Bretschneider (solution HTK) with pure ischemia at 25 degrees C (model A) and Kirklin's or St. Thomas's cardioplegia and subsequent 210 min or HTK cardioplegia and 300 min ischemia at 22 degrees C plus 20 min subsequent reperfusion (model B) leads to the following results: Model A: Compared with pure ischemia cardioplegia according to Kirklin and the St. Thomas's Hospital slows down the decay of the left ventricular ATP-concentration by a mean factor of 3 and the progression of structural alterations of the left ventricular subendocardium by a factor of 2. HTK retards the ATP-decay by a factor of 6, the alterations of ultrastructure by a factor of 6.5. St. Thomas's solution, in contrast to all other methods of cardioplegia, at the onset of ischemia already causes a cellular edema of myocytes; the edema increases during ischemia, and at the ATP-concentration of 4 mumol per gram myocardium is more pronounced than with pure ischemia, Kirklin or HTK. After application of Kirklin's solution, in contrast, a cellular edema of capillary endothelia develops during ischemia, which at 4 mumol ATP is more pronounced than with each of the other methods. Model B: After global ischemia until the ATP-concentration of left ventricular myocardium is 4 mumol/g and a subsequent 20 minutes post-ischemic recovery the ultrastructural alterations in principle resemble those occurring during ischemia (model A).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed2001

Monitoring of intrathecal oxygen tension during experimental aortic occlusion predicts ultrastructural changes in the spinal cord.

OBJECTIVE: To study the correlation between intrathecal PO2 and ultrastructural changes in the spinal cord during thoracic aortic occlusion in pigs. MATERIAL AND METHODS: In 18 pigs, online intrathecal oxygenation was monitored by a multiparameter Paratrend catheter (Biomedical Sensors, High Wycombe, United Kingdom) during 60 minutes' clamping of the proximal and distal descending thoracic aorta. The animals were randomly divided into 2 groups (A and B) depending on the level of distal aortic clamping. Distal aortic perfusion was restored through an aorto-iliac shunt, which also maintained low thoracic segmental perfusion of the spinal cord in group B. Perfusion-fixation technique was used before harvesting the spinal cord specimens, which later were evaluated with light and electron microscopy by an independent observer. Intrathecal parameters were interpreted as normal if PO2 was more than 0.8 kPa and PCO2 was less than 12 kPa, as intermediate ischemia if PO2 was 0.8 or less or PCO (2) was more than 12 kPa, and as absolute ischemia if PO2 was 0.8 or less and PCO2 was more than 12 kPa. RESULTS: Among 6 animals with ultrastructural changes of absolute spinal cord ischemia-reperfusion injury, 5 also had absolute ischemia according to variables derived by the Paratrend catheter. The 2 methods were in agreement in 3 of 5 animals with intermediate ischemia-reperfusion changes and in 5 of 6 animals with normal findings. The accuracy of cerebrospinal fluid PO2 and PCO2 to predict electron microscopy-verified intermediate or absolute ischemia-reperfusion injury was 94%. CONCLUSIONS: Monitoring of intrathecal PO2 after clamping of the descending aorta correlated with ultrastructural changes in the spinal cord in this pig model.

Animals↗
PubMed1999

The ultrastructure and metabolism of ejaculated tammar wallaby sperm are impaired by swim-up procedures when compared with sperm from the cauda epididymidis.

The metabolism, rate of intracellular accumulation of sugars, motility and ultrastructure of ejaculated tammar sperm were impaired by swim-up into artificial media, particularly when the cells were subsequently exposed to N-acetyl-D-glucosamine (NAG). The inclusion of hyaluronate, serum albumin, catalase or Desferal in swim-up media helped prevent deterioration of sperm motility, but failed to prevent detrimental NAG-induced metabolic and ultrastructural changes. However, the sperm were unavoidably diluted during swim-up into artificial media and their behavioural properties were modified by dilution. Thus, sperm collected from the cauda epididymidis were immotile and their rate of oxygen uptake was low in undiluted caudal epididymal semen (CES). Nevertheless, these sperm were viable, and vigorous motility was induced by 5- to 50-fold dilution in Krebs-Ringer phosphate (KRP). Sperm respiration also dramatically increased with moderate dilution (5- or 15-fold) in KRP, but decreased again at higher rates (50-fold). This suggested that motility and the metabolic properties of tammar sperm are modified both by dilution and on leaving the suppressing conditions of the epididymis. Diluted tammar epididymal sperm also displayed a Pasteur effect, but rapidly lost capacity for motility in an oxygen-depleted atmosphere. It was concluded that swim-up procedures compromise ejaculated tammar sperm by promoting dilution-induced changes. This may alter the permeability of the membrane with loss of the enzymes that process the ammonia generated during the metabolism of NAG in seminal plasma. Subsequent exposure to NAG further promotes ultrastructural damage culminating in loss of viability.

Acetylglucosamine↗
PubMed1982

The primary ultrastructural defect caused by anophthalmic white (Wh) in the Syrian hamster.

Anophthalmic white (Wh) of the Syrian hamster is a highly pleiotropic dominant spotting color mutation causing homozygotes to be deaf, blind, and white. An ultrastructural analysis of embryonic tissue reveals that Wh causes the retention of cilia by cells of opposing layers of the embryonic retina and by the lens fiber cells. Previous ultrastructural analyses indicate that Wh also causes the retention of cilia by secretory cells of the anterior lobe of adult pituitaries. We propose that the primary ultrastructural defects caused by Wh is the retention of cilia by embryonic cells. These retained cilia are hypothesized to interfere with normal cell-cell interactions and subsequent cell differentiation.

Animals↗
PubMed1982

Ultrastructure of the membrane attack complex of complement: detection of the tetramolecular C9-polymerizing complex C5b-8.

The ultrastructure of the membrane attack complex (MAC) of complement had been described as representing a hollow cylinder of defined dimensions that is composed of the proteins C5b, C6, C7, C8, and C9. After the characteristic cylindrical structure was identified as polymerized C9 [poly(C9)], the question arose as to the ultrastructural identity and topology of the C9-polymerizing complex C5b-8. An electron microscopic analysis of isolated MAC revealed an asymmetry of individual complexes with respect to their length. Whereas the length of one boundary (+/- SEM) was always 16 +/- 1 nm, the length of the other varied between 16 and 32 nm. In contrast, poly(C9), formed spontaneously from isolated C9, had a uniform tubule length (+/- SEM) of 16 +/- 1 nm. On examination of MAC-phospholipid vesicle complexes, an elongated structure was detected that was closely associated with the poly(C9) tubule and that extended 16-18 nm beyond the torus of the tubule and 28-30 nm above the membrane surface. The width of this structure varied depending on its two-dimensional projection in the electron microscope. By using biotinyl C5b-6 in the formation of the MAC and avidin-coated colloidal gold particles for the ultrastructural analysis, this heretofore unrecognized subunit of the MAC could be identified as the tetramolecular C5b-8 complex. Identification also was achieved by using anti-C5 Fab-coated colloidal gold particles. A similar elongated structure of 25 nm length (above the surface of the membrane) was observed on single C5b-8-vesicle complexes. It is concluded that the C5b-8 complex, which catalyzes poly(C9) formation, constitutes a structure of discrete morphology that remains as such identifiable in the fully assembled MAC, in which it is closely associated with the poly(C9) tubule.

Complement C9↗
PubMed2001

A comparison of different embedding media on the ultrastructure of the trabecular meshwork.

PURPOSE: To determine whether the preservation of the extracellular matrix and the ultrastructural appearance of the trabecular meshwork are affected by different histologic processing protocols and embedding media. Conventionally used epoxy resins such as Araldite require complete dehydration of tissue, while the acrylic resin LR White requires only partial dehydration, better preserves tissue antigens, and has been reported to preserve more of the extracellular matrix. METHODS: Seven human eyes ranging in age from 2 months to 78 years were dissected and tissue samples from each eye processed and embedded in both Araldite and LR White media. The ultrastructure of the trabecular cells and the extracellular matrix of the meshwork was compared between media. The preservation of the extracellular matrix in the juxtacanalicular region was determined by measuring the amount of material immediately underlying Schlemm(1)s canal. Immunoelectron microscopy was used to determine the composition of this material. RESULTS: Araldite provided better resolution of ultrastructural details than freshly polymerized LR White. After a period of ripening for several months, however, resolution of tissue details in LR White improved. No significant quantitative difference was found in the amount of extracellular matrix underlying Schlemm's canal when comparing the two media. Neither post-mortem time to fixation (up to 31 hr), donor age, nor immersion vs. perfusion fixation technique affected the amount of extracellular material present in the comparison of the two embedding media. Immunogold labeling of the extracellular material within the juxtacanalicular tissue revealed the presence of collagen IV, laminin, and fibronectin in the basement membrane region immediately underlying the inner wall, and also in scattered patches within the juxtacanalicular tissue. CONCLUSIONS: Despite the less rigorous processing required for LR White than epoxy embedding, neither the appearance nor amount of the extracellular material was affected by the different embedding protocols. Prolonged post-mortem time to fixation did not affect the appearance nor amount of extracellular matrix. Immunolabeling revealed that the extracellular matrix of the juxtacanalicular tissue contains components of basement membrane material.

Acrylic Resins↗
PubMed1996

A comparative ultrastructural study of the parotid gland acinar cells of nine wild ruminant species (mammalia, artiodactyla).

The ultrastructural similarities and differences of the parotid gland acinar cells of nine wild ruminants (roe deer, nyala, tahr, Eld's deer, red deer, Pere David's deer, European mouflon, African buffalo, sable antelope) representing three feeding types i.e. concentrate selectors (CS), grass and roughage eaters (GR) and intermediate feeders (IM) were compared. The parotid acinar cells of the CS contained more granular endoplasmic reticulum, Golgi-complexes and secretory granules than those of the GR. The acinar cells of the latter were characterized by numerous mitochondria, folded plasma membranes and intercellular secretory canaliculi. The ultrastructure of the secretory granules varied in different species but their morphology was not related to feeding type. An unusual feature of the parotid acinar cells of all feeding types was the evidence of an apocrine-like mode of secretion. A typical morphological change of some parotid acinar cells was the compression of the nucleus by large vacuoles. No distinctive differences were found in the ultrastructure of the parotid gland of wild and captive ruminants.

Animals↗
PubMed2003

Ultrastructural localisation of Muc-1 on the plasma membrane of uterine epithelial cells.

The presence and distribution pattern of Muc-1 was determined immunohistochemically in rat uterine epithelial cells and localised ultrastructurally on the plasma membrane of uterine epithelial cells. Rat uterine tissue was examined on days 1, 3 and 6 of pregnancy and it is shown to be expressed in uterine luminal epithelial cells on day 1 of pregnancy with decreasing expression towards the time of implantation on day 6. It was demonstrated ultrastructurally that Muc-1 is expressed at the external surface of the plasma membrane of uterine epithelial cells thus confirming that it is well positioned to act as an anti-adhesive molecule during the nonreceptive stage of pregnancy. Ultrastructural localisation also revealed that Muc-1 was not present on the outer surface of the plasma membrane during the receptive phase.

Animals↗
PubMed2003

Ultrastructural features of mast cells in picryl chloride (PCL)-induced contact dermatitis in IQI/Jic mice.

Mast cells are one of the major effector cells in the pathogenesis of allergic diseases such as contact dermatitis. In the present study, ultrastructural features of mast cells in contact dermatitis were examined. Namely, the ear of IQI/Jic mice was topically applied with picryl chloride (PCL) at 4 (1st), 11 (2nd), 18 (3rd) and 25 days (4th) after the sensitization with PCL to the abdominal skin. The changes in the ear swelling responses, total serum IgE levels and histology including mast cell numbers were similar to those of previous reports by our research group (Ikeda et al. 2000; Jung et al. 2001). Ultrastructurally, after the 1st application, a close spacial relationship between mast cells and neutrophils and phagocytosis of mast cell granules by neutrophils were observed. Mast cells generally contained non-fused swollen granules filled with altered contents with low electron density and showed an extrusion of membrane-free granules through membrane pores. In addition, interestingly, a few mast cells secreted membrane-bound granules into the dermis without leaving cell membrane damage. After the 4th application when the number of mast cells prominently increased and the total serum IgE level was greatly elevated, in addition to mast cells showing typical anaphylactic degranulation, many mast cells probably in the recovery process from degranulation and several immature mast cells characterized by well-developed Golgi apparatus, many ribosomes and a few electron-dense secretory granules in the peripheral cytoplasm were also observed at the same time. The present results clarified the ultrastructural features of mast cells in the course of PCL-induced contact dermatitis in IQI/Jic mice.

Anaphylaxis↗
PubMed2002

An ultrastructural study of chronic chromate hand dermatitis.

Occupational chromate dermatitis is one of the most common occupational diseases, predominantly causing hand eruptions. The ultrastructural manifestations of this condition have not been previously described. In this study, 7 cases of chronic occupational chromate hand dermatitis were investigated. Biopsies were taken from palmar skin and examined using light and electron microscopy. The ultrastructural features of chronic chromate dermatitis are similar to those of acute inflammatory dermatoses, even in the absence of clinical or histological features of an acute inflammatory process. Most changes are probably mechanical in nature and are a result of increasing intercellular oedema. Several features of chronic chromate dermatitis are common to other inflammatory dermatoses, including the presence of marked intercellular oedema of the lower epidermal keratinocytes, the formation of intracellular vacuoles in cells of the lower epidermis and the presence of milder ultrastructural changes in the midepidermis. The study has documented the presence of dendritic, spindle-shaped granular cells in the upper dermis, which have not previously been described in chromate dermatitis. The epidermis in chromate dermatitis appears to have fewer desmosomes when compared with other forms of dermatitis.

Adult↗
PubMedDate not supplied

Effect of protective agent against lipid-solvent-induced damages. Ultrastructural and scanning electron microscopical study of human epidermis.

The ultrastructural and relief (cyto-architectural) changes of human epidermis following exposure to a protective gel and acetone or kerosene were studied in healthy volunteers. Topical applications of acetone and kerosene on unprotected skin produced cell damage and a disorganized pattern in the upper layers of epidermis. The ultrastructural changes following acetone consisted of large paranuclear vacuoles, swollen mitochondria, and clumped tonofilaments. Severe disorganization with intense cytolysis and enlarged intercellular spaces occurred after exposure to kerosene. Scanning electron microscopy revealed edematous connified cells (corneocytes) following acetone exposure, whereas kerosene induced the occurrence of large lacunae in the swollen corneocytes. The application of a protective agent prior to solvent exposure substantially reduced the ultrastructural and relief changes of epidermal cells.

Acetone↗
PubMed2000

Ultrastructure of the polymorphonuclear leucocytes in human immunodeficiency virus infection.

The ultrastructure of polymorphonuclear leucocytes (PMNL) was studied in 16 patients infected with the human immunodeficiency virus (HIV). PMNL were isolated from HIV-infected patients with CD4+ lymphocytes counts > 200/mm3 (without signs of active infection) (n = 12) (group 1), or < 200/mm3 (n = 4) (group 2), and from 16 healthy volunteers (group 3). Immunoelectron microscopy staining using an anti-beta 2 integrin antibody (anti-CD18) was performed on PMNL from three individuals of group 2 and of three individuals of group 3, before and after incubation with N-formyl-methionyl-leucylphenylalanine (f-MLP). The radical oxygen intermediates (ROI) production of PMNL was investigated by luminol-mediated chemiluminescence. A number of ultrastructural abnormalities in PMNL were found in a higher proportion in HIV-infected patients. These were: (a) an increase in the size of the Golgi apparatus and in the number of mitochondria, and in the quantity of endoplasmic reticulum; (b) some dysplastic features including large cytoplamic vacuoles, whorl of myelin, and nuclear pockets; (c) an increase prevalence of multivesicular bodies compared with control PMNL; (d) some cylindrical confronting cisternae and tubuloreticular structures. After anti-CD18 staining, gold particles were seen on the plasma membrane and more rarely inside the cytoplasm of PMNL from each group but no decrease in this staining was noted in HIV PMNL. Incubation with f-MLP similarly increased the immunostaining of the PMNL in each group. In vitro ROI production was significantly depressed for HIV PMNL compared with control PMNL. Some ultrastructural abnormalities observed in this study could support the possibility that one of the mechanisms underlying the qualitative functional defects of PMNL from HIV-infected patients may be related to some cytopathic effect.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Histopathological and ultrastructural features of dermal telangiectasias in systemic sclerosis.

AIMS: To investigate the histological, ultrastructural and immunohistochemical features of the vascular lining of dermal telangiectasia, a characteristic clinical finding in scleroderma. METHODS: Standard histological, electron microscopic and immunohistological techniques were used to examine dermal telangiectasias in five patients with limited scleroderma, the most common scleroderma variant in Caucasian populations. RESULTS: The telangiectasias were dilated postcapillary venules located in the papillary and superficial reticular dermis. The vessel walls consisted of non-fenestrated endothelial cells surrounded by a variable number of pericytes and smooth muscle cells. There were no unique ultrastructural features. Thickened collagen fibres in the reticular or deep dermis were seen in all but one patient, although in variable and generally minimal quantities. Surrounding infiltrating inflammatory cells were scarce. No enhanced endothelial staining was obtained with antibodies directed against endoglin, endothelin, E-selectin and ICAM-1 suggesting a resting or inactivated state. CONCLUSION: The immunohistological and ultrastructural features of the lining endothelium of established telangiectasias in long-standing, limited scleroderma appear benign. It would be of interest to examine telangiectasias in the early phase of their formation. Alternatively, other explanations need to be explored in understanding the aetiopathogenesis of telangiectasia in scleroderma.

Aged↗
PubMed1996

Ultrastructural evidence of intestinal mucosal macrophage activation after bone marrow transplantation.

Previous studies have demonstrated upregulation of intestinal mucosal macrophage CD16 (an Fc receptor for IgG) in bone marrow transplant (BMT) recipients with graft-versus-host disease (GVHD). We sought to determine whether there was ultrastructural evidence of mucosal macrophage activation in allogeneic BMT recipients and relate appearances to those seen in autologous BMT patients and to immunohistological findings. Sigmoid colonic mucosal biopsies from five allogeneic and three autologous BMT patients were taken prior to, 30 days after transplant and, in three of the allogeneic patients, 120 days after transplant. These were examined by immunohistochemistry and electron microscopy. Immunohistological analysis revealed upregulation of lamina propria macrophage CD16 after transplant in all patients except one autologous BMT recipient; there were no such changes in total macrophage numbers. Ultrastructural evidence of lamina propria macrophage activation was prominent after both allogeneic and autologous BMT. There was an increase in nuclear size accompanied by increased euchromatin and larger nucleoli. In the cytoplasm there were increased numbers of lysosomes, many of which were small and cylindrical, and cytoplasmic flaps were prominent. Phagosomes were less numerous after transplant. These data confirm that after BMT intestinal mucosal macrophages become activated. However changes in macrophage ultrastructure specific to patients at risk of developing clinical GVHD are lacking.

Adult↗
PubMed2002

Ischemia, whether from ligation or torsion, causes ultrastructural changes on the contralateral testis.

OBJECTIVE: Unilateral testicular torsion results with a decrease in contralateral testicular blood flow caused by a reflexive sympathetic response. The aim of this study was to investigate whether twisting of the spermatic cord, or testicular ischemia without twisting, activates this reflex mechanism and causes ultrastructural changes in the contralateral side. MATERIALS AND METHODS: Thirty adult male albino Wistar rats were randomly allocated into three groups of sham, torsion, and ligation. Right testes were twisted 720 degrees counterclockwise in the torsion group. Right spermatic cords were ligated permanently with a silk suture including the vas deferens in the ligation group. After 24 h of testicular ischemia, contralateral left testes were removed for electron microscopic evaluation. RESULTS: Contralateral testes showed similar ultrastructural changes in the torsion and ligation groups. The fibrous tunica propria enveloping the seminiferous tubule was thickened due to increased collagen fibers. The basal lamina was continuous but thickened and showed several foldings. The gap between basal lamina and the germ cells was increased because of collagen fibers. Leydig cells showed mitochondrial degeneration with the loss of its cristae. Leydig cells lost their contact with its neighborhood cells in some areas, and these gaps were filled with collagen fibers. Germ cells showed dilated cisternae of smooth endoplasmic reticulum, cytoplasmic electron-dense bodies and clear regions. CONCLUSIONS: Similar electron microscopic findings observed in the torsion and ligation groups indicate that testicular ischemia rather than twisting of the spermatic cord is responsible for the ultrastructural changes in the contralateral side.

Animals↗
PubMedDate not supplied

Ultrastructural features of "solid cell nest" of the human thyroid gland: a study of 8 cases.

The ultrastructural features of solid cell nests (SCN), made of squamous cells, and associated calcitonin cells (C cells), of the thyroid gland were studied in only a few cases in humans. A study was performed on 8 paraffin-embedded SCN, postembedded in Epon, to look for their ultrastructural features. Immunohistochemical analysis using calcitonin antibody was performed on semithin sections of SCN to explore the presence of C cells. Three cases (37.5%) of SCN were positive for calcitonin, and electron-dense secretory granules were observed in the cytoplasm. In two of these cases, an increased number of C cells in the adjacent thyroid parenchyma was observed. The presence of ciliated and lymphoid cells, in addition to intracytoplasmic microvacuolar and microfollicular (microglandular) structures, was noticed. Ciliated cells have already been reported in embryonic rests of human and animals, but ultrastructurally for the first time in human SCN. The presence of microfollicular structures, intracytoplasmic microvacuolar, secretory granules features, and ciliated cells, in addition to lymphoid cell, suggests the existence of a common ultimobranchial stem cell for C cells or for one or more cell types of the thyroid gland.

Aged↗
PubMedDate not supplied

Ultrastructural pathology of the heart in patients with beta-thalassaemia major.

Patients with beta-thalassaemia major frequently suffer from hypersiderosis which leads to hemochromatosis of major organs such as the heart and liver. Little information exists about the ultrastructural pathology of the human heart in beta-thalassaemia patients. Five Cypriot patients with elevated blood ferritin and intractable heart failure were investigated. Cardiac biopsies from these patients were studied by light and electron microscopy, as well as by X-ray microanalysis. Ultrastructural examination revealed the presence of disrupted myocytes showing loss of myofibers, dense nuclei, and a variable number of pleomorphic electron dense granules. These cytoplasmic granules or siderosomes consisted of iron-containing particles as confirmed by X-ray microanalysis. It is likely that the ultrastructural changes observed in myocytes of patients with beta-thalassaemia are largely due to iron deposition.

Adult↗
PubMedDate not supplied

Brenner tumor of the ovary: a comparative immunohistochemical and ultrastructural study with transitional cell carcinoma of the bladder.

Because of a fancied light microscopic resemblance to transitional epithelium (urothelium), Brenner tumor (BT) of the ovary is commonly described as a transitional cell neoplasm. An inability to detect a great deal of similarity between the two at the ultrastructural level prompted this electron microscopic study comparing 3 benign Brenner tumors with normal urothelium and 6 transitional cell carcinomas (TCC) of varying histologic grade from the urinary bladder. To complement the ultrastructural observations, the immunophenotype of 8 benign BTs was evaluated together with that of 12 TCCs of the bladder using antibodies to thrombomodulin (TM), cytokeratin 20, cytokeratin 7, and carcinoembryonic antigen (CEA), all of which have been shown to react with TCCs of urothelial origin. At the ultrastructural level, there was only limited evidence of a morphologic likeness between the epithelial cells of BTs and those of the benign or neoplastic urothelium. The immunophenotype of the two tumors also differed significantly in that there was no reactivity for TM or cytokeratin 20 in the BTs, while these markers were expressed in the TCCs. Both BTs and TCCs were positive for cytokeratin 7 and may express CEA.

Aged↗