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PubMed2005

Ultrastructural morphometry using dual axes tangential scale: a technical revelation.

While performing ultrastructural morphometry, under or over estimation of ultrastructural size could be avoided by using accurate measuring devices. Biological investigators have always relied on conventional linear scale for the baseline measurement of ultrastructural size parameters on electron micrographs to project the dimensions of intracellular organelles or tissue components. Since it was not possible to measure decimal fractions of mm with linear scale, a 'dual axes tangential scale' has been designed for measuring ultrastructural image parameters on electron micrographs with an accuracy of 0.1 mm to minimize the error in finally computed size of ultrastructural component. In an exercise using 'dual axes tangential scale' and 'conventional linear scale', measurement of glomerular basement membrane thickness (GBMT) as orthogonal intercepts across the GBM revealed a 'coefficient of variation' at 4.4% with dual axes tangential scale as compared to 'coefficient of variation' at 10.9% with linear scale, expressing superiority of dual axes tangential scale over linear scale. Use of mathematical formula rather than nomogram has been preferred. However, 'slide guide, ultrastructure size calculator' could also be used for discerning ultrastructural size after measurement with dual axes tangential scale.

Glomerular Basement Membrane↗
PubMed1998

Ultrastructure of human scalp hair shafts as revealed by freeze-substitution fixation.

Human scalp hair is important as a diagnostic clue to many diseases, in medical jurisprudential investigations, and also as a subject of cosmetic treatments. While many ultrastructural studies of the human hair root including the hair follicle have been reported, few studies have been done on the human hair shaft. We report here the ultrastructure of human scalp hair shafts prepared by a rapid-freezing technique followed by freeze-substitution fixation that allows the observation of fine cell structures. Healthy scalp hair shafts from Japanese females 12-13 years of age were rapid-frozen and then freeze-substituted in OsO4-acetone. In addition, this technique was applied to the study of some changes of the hair shafts (i.e., hair damaged by thioglycolic acid cold permanent waving and white hair). By this method, the hair shaft was rapid-frozen throughout without appreciable ice damage although the hair shaft was nearly 100 microm in diameter. The rapid-freezing technique resulted in excellent preservation of the ultrastructure of the hair shafts: lamellar structures in the cuticle and fine fibrous ultrastructures in the cortex were observed without chemical treatments. Thioglycolic acid treatment affected the ultrastructure of both the cuticle and the cortex. Except for the absence of melanin granules, no significant differences in the ultrastructure were observed between white hair and black hair. The rapid-freezing technique followed by freeze-substitution fixation appears to be the most reliable approach for the morphological evaluation of fully keratinized cells and tissues.

Adolescent↗
PubMed2005

Acute effects of pulsed microwaves and 3-nitropropionic acid on neuronal ultrastructure in the rat caudate-putamen.

Ultrastructure of the medium sized "spiny" neuron in rat dorsal-lateral caudate-putamen was assessed after administration of 3-nitropropionic acid (3-NP) and exposure to pulsed microwaves. Sprague-Dawley male rats were given two daily intraperitoneal doses of 0 or 10 mg/kg 3-NP and 1.5 h after each dose were exposed to microwave radiation at a whole body averaged specific absorption rate (SAR) of 0 (sham exposure), 0.6, or 6 W/kg for 30 min. Microwave exposure consisted of 1.25 GHz radiation delivered as 5.9 micros pulses with repetition frequency 10 Hz. Tissue samples taken 2-3 h after the second sham or microwave exposure showed no injury with light microscope methods. Blinded qualitative assessment of ultrastructure of randomly selected neurons from the same samples did reveal differences. Subsequent detailed, quantitative measurements showed that, when followed by sham exposure, administration of 3-NP significantly increased endoplasmic reticulum (ER) intracisternal width, ER area density, and nuclear envelope thickness. Microwave exposure at 6 W/kg alone also significantly increased these measures. Exposure of 3-NP treated animals at 6 W/kg significantly increased effects of 3-NP on ultrastructure. Although exposure at 0.6 W/kg alone did not affect ultrastructure measures, exposure of 3-NP treated animals at 0.6 W/kg reduced the effects of 3-NP. We concluded that 3-NP changed neuronal ultrastructure and that the microwave exposures used here changed neuronal ultrastructure in ways that depended on microwave SAR and neuron metabolic status. The apparent cancellation of 3-NP induced changes by exposure to pulsed microwaves at 0.6 W/kg indicated the possibility that such exposure can protect against the effects of mitochondrial toxins on the nervous system.

Acute Disease↗
PubMed2002

Ultrastructural studies define soluble macromolecular, particulate, and cellular transendothelial cell pathways in venules, lymphatic vessels, and tumor-associated microvessels in man and animals.

We present de novo studies and review published efforts from our laboratory, spanning 12 years (from 1988 to 2000), where we have used ultrastructural approaches to study the functional anatomy of the microvasculature in man and animals in health and disease. These efforts have defined a new endothelial cell organelle, termed the vesiculo-vacuolar organelle (VVO), which participates in the regulated transendothelial cell passage of soluble macromolecules. The studies defining this organelle utilized ultrathin serial sections, three-dimensional computer-assisted reconstructions, and ultrastructural electron-dense tracers to establish luminal to abluminal transendothelial cell continuity of VVOs. Commonality of VVOs and caveolae is suggested by the ultrastructural anatomy of individual units of VVOs and caveolae, the presence of caveolin in both structures, and a mathematical analysis of morphometric data, all of which suggest that VVOs form from fusions of individual size units equivalent to vesicles of caveolar size. Ultrastructural studies have localized potent permeability factors and their specific receptors to VVOs in in vivo tumor and allergic inflammation models. Regulation of permeability through VVOs has been quantified and shown to be increased in tumor microvessels and in control vessels exposed to potent permeability-inducing mediators. The transendothelial cell passage of particulate macromolecules occurs by vacuolar transport in tumor vessels; in permeability factor-exposed control vessels, colloidal carbon traversed endothelial cells via the development of pores that did not communicate with or disrupt intercellular junctions by gap formation. Serial section and computer-assisted reconstructions established these findings and suggested the possible development of transendothelial cell pores from VVOs. Serial sectioning and computer-assisted three-dimensional reconstructions of ultrastructural samples of an acute inflammation model revealed a transendothelial cell traffic route for motile neutrophils and platelets in the absence of classical ultrastructural criteria for regulated secretion from either cell.

Animals↗
PubMed2006

An environmentally-relevant mixture of organochlorines and its vehicle control, dimethylsulfoxide, induce ultrastructural alterations in porcine oocytes.

Organochlorine chemicals accumulate in the environment, particularly in the Arctic, and constitute potential developmental hazards to wildlife and human health. Although some of their harmful effects are recognized, their mechanisms of action within the target cells need to be better understood. This study was designed to test the hypothesis that an environmentally-relevant organochlorine mixture alters oocyte ultrastructure in the porcine model. Immature cumulus-oocyte complexes (COCs), partially cultured (18 hr) COCs without treatment or exposed to the organochlorine mixture or its vehicle (0.1% dimethysulfoxide; DMSO) during culture were processed for light and transmission electronic microscopy (TEM). The organochlorines induced major ultrastructural changes in the COCs: decreased density of the lipid droplets, increased smooth endoplasmic reticulum (SER) volume and increased interactions among SER, mitochondria, lipid droplets and vesicles. We suggest that these ultrastructural changes facilitate energy formation necessary to produce metabolizing enzymes. Other ultrastructural changes may reflect some degree of organochlorine toxicity: fewer gap junctions and decreased electron density of the cortical granules. Unexpectedly, the DMSO control treatment also induced similar ultrastructural changes, but to a lesser degree than the organochlorine mixture. This study is the first to demonstrate the effect of environmental contaminants on mammalian oocyte ultrastructure.

Animals↗
PubMed1984

Functional differentiation of the anterior pituitary cells in the fetal pig. An ultrastructural immunocytochemical study.

The fetal porcine pituitary was investigated by means of ultrastructural immunocytochemistry (1) to identify the first cells synthesizing the adenohypophyseal hormones, (2) to follow their differentiation during fetal development, and (3) to compare their ultrastructural characteristics with those of mature adult cells. The first ACTH-cells, which produced and stored ACTH, beta-LPH, beta-MSH, and alpha- and beta-endorphin in the same granules, were very numerous at day 34 and displayed a uniform morphology. At day 50 and thereafter, until the end of gestation, the ACTH-cells differed in their appearance probably reflecting various stages of differentiation of one cell type. The GH-cells gained rapidly ultrastructural features comparable to those of mature GH-cells. In contrast, in the case of PRL-cells, which appeared only at the end of the gestation period as immature elements containing very small secretory granules, the morphological maturation seemed to take place only after birth. The first cells synthesizing the glycoprotein hormones (LH alpha, LH beta, FSH and TSH) displayed ultrastructural features of immature cells. At day 50, their ultrastructural organization started to show a different pattern. At the end of gestation, the TSH-cells and the gonadotropic cells displayed the ultrastructural features of mature cells.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

The role of post-ischaemic reperfusion in the development of microvascular incompetence and ultrastructural damage in the myocardium.

To determine the contribution of oxygenated reperfusion to the development of myocardial microvascular incompetence and ultrastructural damage following ischaemia, isolated buffer perfused rat hearts were subjected to either temporary (n = 15) or permanent (n = 15) ischaemia for 15, 30 or 45 minutes. The temporarily ischaemic hearts were reperfused for 5 min with oxygenated Krebs Henseleit buffer. All hearts were then fixed by perfusion fixation with nitrogen-bubbled glutaraldehyde. The transmural development of microvascular incompetence was determined quantitatively by scanning electron microscopy using nuclear track photographic emulsion as an intravascular marker of competent capillaries, and ultrastructural damage was examined by transmission electron microscopy. Thirty or more minutes of ischaemia where required to significantly reduce the mean density of competent capillaries in the subendocardial third of the left-ventricular wall. Such ischaemic myocardium contained relatively normal, open unobstructed vessels, indicating that the microvascular incompetence arising during ischaemia per se was not due to ultrastructural change in the capillaries. Subendocardial myocardium reperfused following 15 min ischaemia also showed little ultrastructural change, but did show a significant reduction in the density of competent capillaries. However, reperfusion of more severely ischaemic myocardium resulted in obvious ultrastructural damage as well as significant further reduction in capillary competence. These findings demonstrate that oxygenated reperfusion of ischaemic myocardium paradoxically results in the further development of microvascular incompetence and, in severely ischaemic myocardium, also to additional ultrastructural damage.

Animals↗
PubMed1996

Ultrastructural consequences of radical damage before and after differentiation of neuroblastoma B-104 cells.

There is abundant evidence that the pathophysiology leading to neuronal death during post-ischemic brain reperfusion involves radical-mediated damage. Although the ultrastructural alterations accompanying brain ischemia and reperfusion are well characterized, little is known about the ultrastructural alterations that are specific to radical damage. This study examines in differentiated and undifferentiated neuroblastoma B-104 cells the viability (by dye exclusion) and ultrastructural consequences of radical damage initiated by 50 microM cumene hydroperoxide (CumOOH). Differentiation was most notably associated with formation of neurites and an extensive cytoskeletal feltwork. CumOOH-induced cell death was increased after differentiation and was blocked by the iron chelator DETAPAC. The ultrastructural characteristics of radical damage here included: (1) plasmalemmal holes that appear to undergo "patching" by well-organized membrane whorls, (2) accumulation of numerous free ribosomes, (3) markedly increased vesicular trafficking about the Golgi accompanied by Golgi transformation from cisternal organization to clusters of vacuoles with numerous fusing vesicles, (4) development of large multi-layered vacuoles that include damage membranes and organelles and appear to undergo extrusion from the cell, and (5) a general loss of cytoplasmic volume. These ultrastructural alterations developed more rapidly and were consistently more advanced in differentiated cells throughout the 6-h time course. In differentiated cells radical damage also induced the disorganization and subsequent loss of the extensive feltwork of cytoskeletal elements. There was little damage to the membranes of the nuclear envelope and mitochondria. Our observations in this system are strikingly similar to ultrastructural alterations in Golgi and ribosomal organization seen in vulnerable neurons during post-ischemic brain reperfusion and suggest that these alterations during reperfusion reflect the consequence of radical-mediated damage.

Animals↗
PubMed1997

The effects of freezing, storage, and thawing on cell compartment integrity and ultrastructure.

The effects of slow freezing and thawing on enzyme compartmentalization and ultrastructure were studied in rat liver slices frozen in dry ice, isopentane/ethanol-dry ice, or liquid nitrogen, and stored at -80 degrees C for 1-14 days. Non-frozen slices served as controls. Frozen liver slices were thawed in a Karnovsky fixative and processed for transmission electron microscopy (TEM). After all freezing protocols, the outer zone of frozen-thawed tissue was ultrastructurally very similar to that of non-frozen liver. Towards the center of the tissue, the ultrastructure progressively deteriorated. Comparison with 50-microm cryostat sections prepared for TEM showed that thawing and not freezing is the detrimental step for fair preservation of ultrastructure. After thawing, homogenization, and differential centrifugation, distribution patterns of soluble marker enzymes were analyzed (cytosol, lactate dehydrogenase; mitochondrial matrix, glutamate dehydrogenase; lysosomes, acid phosphatase). The enzyme activities were not affected by storage for 2 weeks and the activity distributions showed that protein leakage from compartments was only minimally increased in frozen-thawed tissue compared with that from non-frozen tissue, irrespective of the method of freezing. In conclusion, fairly large tissue slices (20x5x3 mm) may be frozen and stored at -80 degrees C for biochemical, ultrahistochemical or ultrastructural studies. For ultrastructural analysis, only the periphery of the tissue slice should be used.

Animals↗
PubMed1998

Ultrastructural pathology of the alveolar type II pneumocytes of human donor lungs. Electron microscopy, stereology, and microanalysis.

Alveolar type II pneumocytes (PII) were studied in 12 human donor lungs perfused with modified Euro-Collins solution during single-lung transplantation (SLTx). While one lung was transplanted, the contralateral donor lung (cDL) was fixed at the time of SLTx for examination by electron microscopy, stereology, and microanalysis. Three groups were then formed: group A (n = 7), cDL without contusions, uneventful early postoperative course; group B (n = 3), cDL with conclusions, uneventful early postoperative course; group C (n = 2), cDL without contusions, early postoperative respiratory dysfunction. The major findings were that the presence of contusions had no effect on PII ultrastructure and that intracellular surfactant-storing lamellar bodies of cDL in group C were characterized by a higher volume-to-surface ratio (VsR) and larger area per cell profile than group A. Correlation analysis based on pooled data (groups A and C) showed that ischaemic time had little effect on PII ultrastructure and bore no relationship to postoperative clinical variables. The duration of preoperative donor intubation had a pronounced influence on ultrastructure and postoperative clinical variables. The stereologically estimated amount of intracellular surfactant and mitochondrial VsR were the only ultrastructural parameters that were significantly associated with early postoperative oxygenation. Lamellar bodies were the only ultrastructural components found to have a significant relationship to postoperative intubation time. The ultrastructural integrity of type II pneumocytes of human donor lungs is an important determinant of early respiratory function following clinical lung transplantation.

Adolescent↗
PubMed1985

Target dependence of Nissl body ultrastructure in cat thoracic motoneurones.

The effects on Nissl body (NB) ultrastructure of muscle reinnervation or neuroma formation were determined in cytochemically identified cat thoracic motoneurones subjected to axotomy by either nerve crush or nerve section with proximal ligation. Normal NB ultrastructure comprised highly ordered lamellae of rough endoplasmic reticulum (RER) with associated linear arrays of unbound polyribosomes. This ultrastructural orderliness was lost following axotomy, with or without light microscopic chromatolysis. While NBs were seen in the light microscope at late stages following both nerve crush or ligation, normal NB ultrastructure was only observed following nerve crush. An inductive effect of the periphery on NB ultrastructure is proposed and the implication of NB ultrastructure discussed in relation to protein synthesis.

Animals↗
PubMed1989

Correlation of ultrastructural aberrations with dysplasia and flow cytometric abnormalities in Barrett's epithelium.

Barrett's esophagus develops as a complication of chronic gastroesophageal reflux and predisposes patients to the development of dysplasia and adenocarcinoma of the esophagus. Because light microscopy of dysplasia in Barrett's esophagus shows diminished or absent mucus, we used transmission electron microscopy to compare cytoplasmic organelles required for mucus production in dysplastic and nondysplastic esophageal columnar epithelium. These observations of the rough endoplasmic reticulum, Golgi apparatus, and secretory granules were correlated with histologic interpretations and flow cytometric measurements of abnormalities of DNA content. Ultrastructural abnormalities included depletion and alteration of organelles required for mucus biosynthesis. These abnormalities often were accompanied by cells with markedly distended rough endoplasmic reticulum and massive accumulation of cytoplasmic glycogen aggregates. All 9 patients who had Barrett's dysplasia with or without early adenocarcinoma had ultrastructural abnormalities, as did 3 of 8 patients whose biopsy histology was indefinite for dysplasia. Abnormalities measured by flow cytometry correlated well with the presence of these ultrastructural aberrations. All 9 patients with Barrett's dysplasia with or without early adenocarcinoma had abnormalities observed by electron microscopy and aneuploidy or increased G2/tetraploid fractions measured by flow cytometry. Two of the 3 patients whose biopsies were indefinite for dysplasia and who had ultrastructural abnormalities also had aneuploidy or increased G2/tetraploid fractions. Neither ultrastructural nor flow cytometric abnormalities were found in the remaining 5 patients whose biopsies were indefinite for dysplasia, in 19 of 22 patients with Barrett's specialized metaplasia, or in any of the 7 patients with gastroesophageal reflux disease without Barrett's specialized metaplasia. Two of the 22 patients with Barrett's specialized metaplasia had distended rough endoplasmic reticulum in rare cells, and one other had an aneuploid cell population. We conclude that neoplastic progression in Barrett's esophagus is associated with abnormalities of cytoplasmic organelles required for mucus production. With few exceptions, these ultrastructural aberrations correspond to the presence of dysplasia or of aneuploidy or increased G2/tetraploid fractions. Electron microscopy and flow cytometery detect abnormalities associated with the development of dysplasia and cancer in Barrett's esophagus that may be biologically significant.

Adenocarcinoma↗
PubMed1998

Morphological investigations of the myocardium of cardiomyopathic hamsters during the postnatal development and experimental hypoxia. A quantitative ultrastructural study.

The hereditary cardiomyopathy of the Syrian hamster (strain BIO 8262) as a model of human cardiomyopathy was investigated during postnatal development using ultrastructural morphometric analysis. The aim of the study was to establish basic ultrastructural morphometric data of cardiomyocytes of this model during all stages of the disease in comparison to corresponding stages of normal development, and to compare the ultrastructural resistance of normal and myopathic myocardium against acute hypoxic stress. The postnatal development of this cardiomyopathy is characterized by focal myolytic lesions already in the first postnatal days, extended myofibrillic and mitochondrial damage developing after the 1st month, and features of hypertrophy, disarray of myofibrils, thickening, and clumping of z-lines after the 4th month. Morphometric parameters of myopathic cardiomyocytes differing from those of the control are diminished volume density of myofibrils by about 10% of the control values in middle age, slightly increased volume density of sarcoplasmic reticulum and t-tubules in the 1st months, significant increase of them after the 3rd month, and significant alterations of many mitochondrial parameters indicating degenerations (numeric density, volume density, average volume, volume density of cristae, and of destroyed areas, and ratio of surface to volume density of mitochondrial cristae). Acute isobaric hypoxia was applied to myopathic and healthy hamsters of corresponding age (at day 100). Evaluation of ultrastructural morphometric parameters of cardiomyocytes revealed that especially mitochondria were more affected by hypoxia in the myopathic animals. The average mitochondrial volume was significantly more increased in the myopathic condition, the ratio of surface to volume density of cristae significantly diminished. Our ultrastructural - morphometric study has shown, that morphometric parameters in general can be assigned to the stages of cardiomyopathy, and that the ultrastructural differences are best expressed about the 4th month.

Animals↗
PubMed2005

Ultrastructural zonal heterogeneity of hepatocytes and mitochondria within the hepatic acinus during liver regeneration after partial hepatectomy.

BACKGROUND INFORMATION: Partial hepatectomy (70%) induces cell proliferation until the original mass of the liver is restored. In the first 24 h after partial hepatectomy, drastic changes in the metabolism of the remaining liver have been shown to occur. To evaluate changes in hepatocyte ultrastructure within the hepatic acinus during the liver regenerative process, we investigated, by light and electron microscopy observations on specimens taken 0 h, 24 h and 96 h after partial hepatectomy, the hepatocyte structure and ultrastructure in the periportal and pericentral area of the hepatic acinus, with a particular emphasis on mitochondria ultrastructure. Moreover, some biochemical events that could affect the mitochondria ultrastructure and function were investigated. RESULTS: We found that, 24 h after partial hepatectomy, mitochondria with altered ultrastructure were preferentially localized in the periportal area. Periportal hepatocytes showed also an increase in the number of peroxisomes, free ribosomes, lysosomes and autophagosomes. Altered mitochondria showed swelling, an ultrastructural index of increased membrane permeability, a reduction in the number of cristae, and a rarefied, often vacuoled, matrix. Consistently, an increase in the mitochondrial oxidized/reduced glutathione ratio was found as well as calcium release from mitochondria in a manner inhibited by cyclosporin A. Interestingly, light and electron microscopy analysis showed that the hepatocytes in the periportal area were the cells with the major structural attributes to proliferate. At 96 h after partial hepatectomy, the preferential zonation of altered mitochondria was lost and the normal mitochondrial membrane permeability properties were restored. CONCLUSIONS: We suggest that 24 h after partial hepatectomy, a preferential zonation of altered mitochondria in the periportal hepatocytes could be involved in the changes of metabolic and functional heterogeneity of the hepatocytes within the hepatic acinus during the regenerative process.

Animals↗
PubMed2004

Ultrastructural changes in the albino guinea pig cochlea at different survival times following cessation of 8-day cisplatin administration.

OBJECTIVE: To investigate the effect of cisplatin administration on the ultrastructural morphology of the organ of Corti, stria vascularis and spiral ganglion. MATERIAL AND METHODS: Forty-eight guinea pigs were treated with cisplatin by daily i.p. injection at a dose of 1.5 mg/kg for eight consecutive days. Electrocochleography was performed at various survival times after the final application of cisplatin. The cochleae were subsequently examined using electron microscopy. RESULTS: Ultrastructural examination corroborated that, in cochlear turns showing complete loss of outer hair cells (OHCs) at the light microscopic level, OHCs were indeed missing and had been completely replaced by supporting cells. OHC loss, the number of affected OHCs and the degree of intracellular pathology in the OHCs in the 1-day, 1-week and 2-week survival groups were considerably higher than in the 4- and 8-week survival groups. All degenerated OHCs demonstrated ultrastructural features commonly associated with necrosis. No morphological signs of apoptosis were observed. Strial changes consisted of protrusion of the apical membrane of the marginal cells into the scala media, without any other histopathological changes. Intermediate-cell atrophy, apparent as translucent areas at the light microscopic level, consisted of an increase in intercellular space due to shrinkage of intermediate and marginal cells ultrastructurally. Ultrastructural examination of the spiral ganglion showed that vacuolation of the spiral ganglion cells, seen at the light microscopic level, was due to severe swelling of the mitochondria. CONCLUSION: The present results corroborate our previous light microscopic findings. However, the ultrastructural results do not allow a conclusion to be drawn concerning whether the observed recovery is due to the formation of new OHCs or to (self-)repair of damaged OHCs, although the latter is less likely.

Animals↗
PubMedDate not supplied

Neuronal ceroid lipofuscinosis: an ultrastructural, genetic, and clinical study report.

The term "neuronal ceroid lipofuscinosis" (NCL) describes a complex of inherited neurodegenerative conditions associated with storage of lipopigments in brain tissue. In 1989 Dyken proposed a classification of NCL based on the age, clinical symptoms, and ultrastructural aspects of the lipopigments. At the ultrastructural level it is possible to distinguish 5 different patterns of osmiophilic lipopigments: usual lipofuscin, fingerprint deposits, granular profiles, curvilinear bodies, and microtubular aggregates. The concept that each ultrastructural pattern was the counterpart of a specific clinical type has been proved not to be true. Advances in molecular genetic techniques have allowed the identification of defective genes and their protein products in several NCL clinical forms. Ceroid lipofuscin deposits may be ultrastructurally observed not only in neuronal cells, but also in several other sites, such as trophoblastic cells, thus permitting prenatal diagnosis. In spite of recent advances in immunohistochemical identification of biochemical markers, the ultrastructural identification of lipofuscinic pigments remains the gold standard to identify NCL, together with clinical aspects and respective gene defects. This study describes the ultrastructural aspects observed in 8 cases of NCL syndromes (3 juvenile, 3 infantile, 1 late infantile, and 1 congenital clinical form). In these patients, genetic analysis was also performed.

Ceroid↗
PubMedDate not supplied

Ultrastructural phenotype of "intestinal-type" cells in columnar-lined esophagus.

An intestinal-type epithelium is often present at columnar-lined esophagus, gastroesophageal junction or within the so-called short segment Barrett's esophagus, but ultrastructural study failed to detect enterocytes in columnar-lined esophagus. The authors have analyzed the intestinal aspects present in areas of columnar-lined esophagus in a population of patients with reflux esophagitis to better understand the morphology and histogenesis of the proliferating elements. Columnar-lined mucosa was studied in 35 patients. Columnarsurface cells displayed a wide spectrum of ultrastructural features. Well-differentiated columnar secretory cells, secretory-absorptive cells, poorly differentiated columnar cells, atypical columnar cells, and goblet cells were detected. Well-differentiated absorptive cells were never found, These results demonstrate that the areas of intestinal metaplasia show a wide spectrum of ultrastructural phenotypes, ranging from poorly to well-differentiated cells. However, true enterocytes were not found and the most represented phenotype is that of secretory-absorptive cells, whose principal characteristic is the presence of secretory and absorptive aspects together. They can be described as secretory enterocytes or cells with double specialization. To the authors' knowledge, similar cells were not previously described in normal intestinal mucosa, and ultrastructural studies are consistent in describing a broad spectrum of ultrastructural features, suggesting that Barrett's specialized metaplasia is derived from cells with the capacity for a wide range of differentiation. Therefore, despite the wide use of term intestinal metaplasia in the medical literature, experimental data clearly failed to detect enterocytes in the columnar-lined esophagus, and ultrastructural data do not support the concept of intestinal metaplasia. The cellular heterogeneity seems to be the result of a "phenotypic shift" of undifferentiated elements, which show a different pattern of evolution. The result of this process is the formation of new cell types dissimilar from those normally present in esophageal, gastric, or duodenal mucosa.

Adolescent↗
PubMed1971

Oxidative phosphorylation and ultrastructural transformation in mitochondria in the intact ascites tumor cell.

We have examined the ultrastructure of mitochondria as it relates to energy metabolism in the intact cell. Oxidative phosphorylation was induced in ultrastructurally intact Ehrlich ascites tumor cells by rapidly generating intracellular adenosine diphosphate from endogenous adenosine triphosphate by the addition of 2-deoxyglucose. The occurrence of oxidative phosphorylation was ascertained indirectly by continuous and synchronous monitoring of respiratory rate, fluorescence of pyridine nucleotide, and 90 degrees light-scattering. Oxidative phosphorylation was confirmed by direct enzymatic analysis of intracellular adenine nucleotides and by determination of intracellular inorganic orthophosphate. Microsamples of cells rapidly fixed for electron microscopy revealed that, in addition to oxidative phosphorylation, an orthodox --> condensed ultrastructural transformation occurred in the mitochondria of all cells in less than 6 sec after the generation of adenosine diphosphate by 2-deoxyglucose. A 90 degrees light-scattering increase, which also occurs at this time, showed a t (1/2) of only 25 sec which agreed temporally with a slower orthodox --> maximally condensed mitochondrial transformation. Neither oxidative phosphorylation nor ultrastructural transformation could be initiated in mitochondria in intact cells by the intracellular generation of adenosine diphosphate in the presence of uncouplers of oxidative phosphorylation. Partial and complete inhibition of oxidative phosphorylation by oligomycin resulted in a positive relationship to partial and complete inhibition of 2-deoxyglucose-induced ultrastructural transformation in the mitochondria in these cells. The data presented reveal that an orthodox --> condensed ultrastructural transformation is linked to induced oxidative phosphorylation in mitochondria in the intact ascites tumor cell.

Adenine Nucleotides↗