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PubMed2004

Ultrastructure of the bladder in classic exstrophy: correlation with development of continence.

PURPOSE: Successful initial surgical management of bladder exstrophy does not always lead to continence. We evaluated the ultrastructure of the exstrophic bladder using electron microscopy (EM) at various stages of reconstruction to determine whether morphology could correlate with the potential for continence. MATERIALS AND METHODS: Bladder specimens obtained from 32 patients undergoing various stages of exstrophy reconstruction were evaluated by EM. Specimens were obtained at primary newborn closure (group 1-10), reclosure following failure (group 2-2), bladder neck reconstruction (group 3-9) and augmentation cystoplasty (group 4-11). Evaluation was performed by a single anatomist with experience with EM. Biopsies were separated into those with good, intermediate or poor ultrastructural parameters and then correlated clinically. RESULTS: In group 1, 4 children had good and 2 had intermediate parameters. All showed increased bladder volumes at followup. Four patients had poor parameters and poor bladder growth. The 2 group 2 children had poor parameters and bladder growth. In group 3, 7 of 9 patients had good and 1 had intermediate parameters. Eight of the 9 patients are doing well. Only 3 of the 11 group 4 children had good parameters and an additional 2 had intermediate parameters. CONCLUSIONS: Ultrastructural evaluation can identify changes in the bladder that may portend a poor prognosis for eventual continence. Although the correlation was good at bladder closure, some patients with good parameters still had failed reconstruction. Since this is a small study, we continue to recommend reconstruction in all patients who have an adequate bladder template.

Biopsy↗
PubMed2005

Ultrastructural analysis of the chorda tympani nerve in chronic suppurative otitis media.

OBJECTIVE: To compare ultrastructure of the chorda tympani nerve by light and electron microscopy in patients with otosclerosis and chronic suppurative otitis media. STUDY DESIGN: Comparative prospective study. SETTING: Tertiary care, referral medical center. PATIENTS: The tympanic segments of chorda tympani nerves were collected for ultrastructural investigation in 20 cases with chronic suppurative otitis media and 10 cases with otosclerosis that underwent middle ear surgery. RESULTS: Histopathologic examinations of the suppurative group showed that unmyelinated fibers were almost totally lost and replaced by collagen fibers. The thickness of the myelin sheaths was very slender, whereas some of them were atrophic. A substantial increase was encountered in the endoneural collagen substance and connective tissue, whereas inflammatory elements and edema were present occasionally. Degenerative alterations of the myelinated fibers mainly occurred in the form of adaxonal vacuoles. There was disorganization and separation of parallel lamellae of Schmidt-Lanterman clefts. CONCLUSION: The chorda tympani nerve should be preserved in otologic surgery. However, inadvertent dissection of the chorda tympani nerve in chronic suppurative otitis media surgery will not possibly cause a postoperative disturbance in light of ultrastructural changes that occur in the nerve.

Axons↗
PubMed1980

Colony morphology, ultrastructure and morphogenesis in Mycoplasma hominis, Acholeplasma laidlawii and Ureaplasma urealyticum.

Colonies of Mycoplasma hominis, Acholeplasma laidlawii (three strains) and Ureaplasma urealyticum were examined by light and electron microscopy and their characteristic morphology, ultrastructure and morphogenesis are described. Mycoplasma hominis and A. laidlawii, PG8 and oral strains, developed typical 'fried-egg' colonies which were remarkably heterogeneous in size. The colonies of A. laidlawii strain NCTC 10116 were more homogeneous and grew mainly on the surface of the agar showing a fine granular appearance. Ureaplasma urealyticum produced smaller, granular colonies which grew deeply embedded in the agar and generally without much surface growth. The cellular ultrastructure in these colonies was also examined. The results indicate that several aspects of colony morphogenesis and ultrastructure varied for each of the three species examined.

Acholeplasma laidlawii↗
PubMed1985

Ultrastructure of bacilli and the bacillary origin of the macrophagic inclusions in Whipple's disease.

An electron microscopic and cytochemical study of the Whipple bacillus in jejunal biopsies from three untreated patients was made using fixation procedures developed for the satisfactory preservation of bacterial ultrastructure. The envelopes of the normal-looking bacilli present free in the lamina propria consisted of the following layers. (i) A cytoplasmic membrane with a triple-layered profile and a mean thickness (peak-to-peak distance) of 6.08 nm. (ii) A thick (20 nm) cell wall containing peptidoglycan; the wall had a hitherto undescribed inner layer that contained polysaccharides, possibly teichoic acids. (iii) Surrounding the cell wall, a surface membrane with a symmetric profile and a mean peak-to-peak distance of 4.74 nm. The ultrastructural pattern of the Whipple bacillus wall corresponds to that of Gram-positive bacteria, but with an additional surface membrane. This membrane is different from the outer membrane of Gram-negative bacteria because it has a symmetric profile, is thinner and has no periodic acid-Schiff (PAS)-positive components. Normal-looking bacilli were seen very rarely inside jejunal macrophages, but degenerating bacteria were abundant in these phagocytes. Electron microscopy and ultrastructural cytochemistry of Whipple bacilli inside jejunal macrophages of the three untreated patients showed that the degenerative process is a sequence that leads to the loss of bacillary forms and to the accumulation of bacterial remnants resistant to degradation by the macrophage. These remnants correspond to the innermost, polysaccharide-containing portion of the bacillus wall. The progressive accumulation of these PAS-positive wall remnants is the origin of the intramacrophagic inclusions that are important in the histological diagnosis of Whipple's disease. The reported results indicate that in the three patients studied, the Whipple bacillus multiplies extracellularly, the bacteria that are phagocytosed by macrophages being degraded.

Bacillus↗
PubMed2003

Ultrastructural observation of Helicobacter pylori in glucose-supplemented culture media.

Helicobacter pylori in the human gut can be divided morphologically into spiral and coccoid forms. The spiral form is known to change into the coccoid form in culture in vitro. The ultrastructural changes and culturability of H. pylori were studied in medium supplemented with different concentrations of glucose. H. pylori ATCC 43504(T) was cultured in liquid medium containing 10 % heat-inactivated horse serum supplemented with glucose (at 0, 10, 100, 300 and 500 mM) for 7 days. Bacterial ultrastructure and culturability were examined daily. With extended time in culture, the spiral forms had transformed into coccoid forms in all media. The coccoid forms could be further divided into two types, A and B, by electron microscopy. The type A coccoid form had an irregular surface with few flagella and indistinct cytoplasmic membrane. The type B coccoid form had a better-maintained integral membrane structure and was the dominant form in 300 mM glucose-supplemented medium. The highest culturability was obtained using 300 mM glucose-supplemented medium. Based on observations of ultrastructural changes in relation to the culturability data, the coccoid forms could be categorized into three stages: dying, viable but non-culturable and proliferating organisms. The optimal glucose concentration for H. pylori culture in this liquid medium culture experiment was approximately 300 mM.

Culture Media↗
PubMed1971

Plants under Climatic Stress: II. Low Temperature, High Light Effects on Chloroplast Ultrastructure.

Mesophyll chloroplasts of the C(4)-pathway grasses Sorghum and Paspalum and of the C(3)-pathway legume soybean undergo ultrastructural changes under moderate light intensities (170 w.m(-2), 400-700 nanometers) at a tme when photosynthesis is much reduced by low temperature (10 C). The pattern of ultrastructural change was similar in these species, despite some differences in the initial sites of low temperature action on photosynthesis and differences in their mechanisms of CO(2) fixation. Starch grains in the chloroplasts rapidly reduce in size when chilling stress is applied. At or before the time starch grains completely disappear the membranes of the individual stromal thylakoids close together, reducing the intraspace between them while the chloroplast as a whole begins to swell. Extensive granal stacking appears to hold the thylakoids in position for some time, causing initial swelling to occur in the zone of the peripheral reticulum, when present. At more advanced stages of swelling the thylakoid system unravels while the thylakoid intraspaces dilate markedly. Initial thylakoid intraspace contraction is tentatively ascribed to an increase in the transmembrane hydrogen ion gradient causing movement of cations and undissociated organic acids from the thylakoid intraspace to the stroma. Chloroplast swelling may be caused by a hold-up of some osmotically active photosynthetic product in the chloroplast stroma. After granal unraveling and redilation of the thylakoid intraspaces, chloroplasts appear similar to those isolated in low salt hypotonic media. At the initial stages of stress-induced ultrastructural change, a marked gradient in degree of chloroplast swelling is seen within and between cells, being most pronounced near the surface of the leaf directly exposed to light.

Journal Article↗
PubMed1983

Ultrastructure of tomato fruit ripening and the role of polygalacturonase isoenzymes in cell wall degradation.

Ultrastructural changes in the pericarp of tomato (Lycopersicon esculentum Mill) fruit were followed during ripening. Ethylene production was monitored by gas chromatography and samples analyzed at successive stages of the ripening process.Changes in the cytoplasmic ultrastructure were not consistent with the suggestion that ripening is a ;senescence' phenomenon. A large degree of ultrastructural organization, especially of the mitochondria, chromoplasts, and rough endoplasmic reticulum, was retained by ripe fruit.Striking changes in the structure of the cell wall were noted, beginning with dissolution of the middle lamella and eventual disruption of the primary cell wall. These changes were correlated with appearance of polygalacturonase (EC 3.2.1.15) isoenzymes. Application of purified tomato polygalacturonase isoenzymes to mature green fruit tissue duplicated the changes in the cell wall noted during normal ripening. Possible roles of the polygalacturonase isoenzymes in cell wall disorganization are discussed.

Journal Article↗
PubMed1984

Chloroplast ultrastructure, chlorophyll fluorescence, and pigment composition in chilling-stressed soybeans.

Shoots of 16-day-old soybeans (Glycine max L. Merr. cv Ransom) were chilled to 10 degrees C for 7 days and monitored for visible signs of damage, ultrastructural changes, perturbations in fluorescence of chlorophyll (Chl), and quantitative changes in Chl a and b and associated pigments. Precautions were taken to prevent the confounding effects of water stress. A technique for the separation of lutein and zeaxanthin was developed utilizing a step gradient with the high performance liquid chromatograph. Visible losses in Chl were detectable within the first day of chilling, and regreening did not occur until the shoots were returned to 25 degrees C. Ultrastructurally, unstacking of chloroplast grana occurred, and the envelope membranes developed protrusions. Furthermore, the lipids were altered to the point that the membranes were poorly stabilized by a glutaraldehyde/osmium double-fixation procedure. Chl fluorescence rates were greatly reduced within 2 hours after chilling began and returned to normal only after rewarming. The rapid loss of Chl that occurred during chilling was accompanied by the appearance of zeaxanthin and a decline in violaxanthin. Apparently a zeaxanthin-violaxanthin epoxidation/de-epoxidation cycle was operating. When only the roots were chilled, no substantial changes were detected in ultrastructure, fluorescence rates, or pigment levels.

Journal Article↗
PubMed1987

Ultrastructure: effects of melanin pigment on target specificity using a pulsed dye laser (577 nm).

It has been shown recently that brief pulses of 577 nm radiation from the tunable dye laser are absorbed selectively by oxyhemoglobin. This absorption is associated with highly specific damage to superficial vascular plexus blood vessels in those with lightly pigmented (type I-II) skin. To determine whether pigmentary differences in the overlying epidermis influence this target specificity, we exposed both type I (fair) and type V (dark) normal human skin to varying radiant exposure doses over 1.5-microsecond pulse durations from the tunable dye laser at a wavelength of 577 nm. Using ultrastructural techniques, we found in type I skin that even clinical subthreshold laser exposures caused reproducible alterations of erythrocytes and adjacent dermal vascular endothelium without comparable damage to the overlying epidermis. In contrast, degenerated epidermal basal cells represented the predominant form of cellular damage after laser exposure of type V skin at comparable doses. We conclude that epidermal melanin and vascular hemoglobin are competing sites for 577 nm laser absorption and damage, and that the target specificity of the 577 nm tunable dye laser is therefore influenced by variations in epidermal pigmentation. This finding is relevant to the clinical application of the tunable dye laser in the ablative treatment of vascular lesions. We also found on ultrastructure that the presence of electron-lucent circular structures of approximately 800 A in diameter were observed only at and above clinical threshold doses in those with type I skin and at the highest dose of 2.75 J/cm2 in type V skin. It has been proposed that these structures might be heat-fixed molds of water vapor. Both this and ultrastructural changes of epidermal basal cells demonstrate mechanisms responsible for alteration of tissue after exposure to 577 nm, which are discussed.

Animals↗
PubMed1977

Ultrastructure of the capillary loops in the dermal papillae of psoriasis.

Electron microscopy was used to define the ultrastructure of the capillary loops in the dermal papillae of psoriatic lesions. Pustular psoriasis of von Zumbusch and psoriasis vulgaris were studied before and after treatment with the Goeckerman regimen. Capillary loops were reconstructed from 1-mum plastic-embedded sections. Ultrathin sections were taken at intervals for correlation with the 1-mum sections. There were no ultrastructural differences between the capillary loops in psoriasis vulgaris and pustular psoriasis. The intrapapillary portion of the loop was predominantly a venous capillary. Four basic ultrastructural loop patterns were recognized which can serve as markers in studying the responses of psoriatic loops in various experimental situations. Following 3 weeks of Goeckerman therapy, the morphology of psoriatic capillary loops changed from venous capillaries to arterial capillaries which are found in the papillae of normal skin. This transformation was observed to begin 48 to 72 hr after the initiation of therapy.

Biopsy↗
PubMed1983

Elemental redistribution and ultrastructural changes in guinea pig epidermis after dinitrochlorobenzene (DNCB) exposure.

Energy dispersive x-ray microanalysis and transmission electron microscopy were used to study ultrastructural and chemical changes occurring in the keratinocytes at the primary irritant dinitrochlorobenzene (DNCB) reaction. The results of the microanalysis showed a similarity between dose- and time-dependent effects of DNCB and were in accordance with the ultrastructural findings. With increasing cell injury (as judged by the ultrastructure) there was an increasing loss of phosphorus, potassium, and magnesium from the cells and an increase of cellular calcium content. Sodium and chloride were only moderately changed. Results recorded when the skin was exposed to a weak DNCB dose were in accordance with a stimulation of the basal keratinocyte cell population.

Animals↗
PubMed1983

Ultrastructure and three-dimensional reconstruction of several macular and papular telangiectases.

Eight types of telangiectases were studied by light and electron microscopy and by 3-dimensional reconstruction from photomicrographs. Five were macular: mat telangiectasia of scleroderma, generalized essential telangiectasia, nevus flammeus, and 2 macular types not previously described. Three were papular: cherry angioma, angiokeratoma (Fabry), and angiokeratoma (Fordyce). The macular telangiectases were produced by dilatation of postcapillary venules of the upper horizontal plexus. There was no evidence of neovascularization or vascular malformation. The walls of the dilated venules were thickened by the peripheral deposition of basement membrane-like material admixed with reticulin fibers. The ultrastructure and configuration of the papular telangiectases were different. The cherry angioma was produced by spherical and tubular dilatations of capillary loops in dermal papillae. Each abnormally dilated loop was connected to the neighboring loop or loops by tortuous vascular channels. The vessels in the upper horizontal plexus were not involved. Ultrastructurally, the cherry angiomas were composed of both venous capillaries and postcapillary venules whose walls were thickened in a manner identical to that observed in the macular telangiectases. The angiokeratomas of Fabry and Fordyce were also produced by vascular abnormalities predominantly involving the dermal papillae. Ultrastructurally these vessels were similar to the small collecting veins which are normally found at the dermal-subcutaneous interface. Thus, the papular telangiectases also arose by alterations of the existing microvasculature rather than by proliferation of new vessels with random anastomoses. Reconstruction of the upper horizontal plexus from normal skin showed an undulating network of arterioles and their accompanying postcapillary venules. A 3-layered plexus arranged as venules, arterioles, and venules was not found.

Adolescent↗
PubMed1989

Ultrastructure and organization of the cutaneous microvasculature in normal and pathologic states.

The cutaneous microvasculature is organized into upper and lower horizontal plexuses with the dermal capillary loops arising from the upper plexus. The arteriolar and venular sides of the microvasculature can be identified by the ultrastructure of the mural basement membrane material. Collecting venules present in the lower dermis contain valves. Periadventitial cells (veil cells) are present around all microvessels. Their size and number appear to correlate with the quantity of mural basement membrane material found in cutaneous vessels in diabetes, actinic damage, and chronological aging. The contractile cells of the vascular wall surround the endothelial cell tube in a manner suggesting specific functions. The smooth muscle cells in the arteriolar segment form a sleeve, whereas each pericyte in the postcapillary venular simultaneously makes many contacts with several underlying endothelial cells. The common telangiectases can be explained by abnormalities in this organization and ultrastructure rather than by neovascularization or random anastomoses. The macular telangiectases seen in scleroderma, generalized essential telangiectasia, and nevus flammeus are produced by dilatation of the postcapillary venules of the upper horizontal plexus. Cherry angiomas are produced by spherical and tubular dilatations of capillary loops in dermal papillae with tortuous cross-connections between individual loops. Angiokeratomas of Fabry and Fordyce have the ultrastructure of collecting venules that contain valves, and appear to represent the ectopic development or placement of small valve-containing collecting veins. The cutaneous lesions of hereditary hemorrhagic telangiectasia represent arteriovenous communications.

Animals↗
PubMed2005

Ultrastructural features of trafficking defects are pronounced in melanocytic nevus in Hermansky-Pudlak syndrome type 1.

Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder characterized by oculocutaneous albinism, a bleeding disorder, and ceroid lipofuscinosis in the lungs and gut. HPS is genetically heterogeneous and the most common variant, HPS type 1, is caused by mutations in HPS1 gene. The protein encoded by HPS1 is considered to facilitate the trafficking of melanocyte-specific gene products into the premelanosome. We report the ultrastructural findings in a melanocytic nevus seen in a 17-y-old Japanese female patient with HPS1 who is a compound heterozygote of HPS1 mutations, including a novel mutation. Electron microscopy of a pinkish papule corresponding to the melanocytic nevus revealed markedly aberrant, immature melanosomes, large membranous structures, and giant melanosomes in the vicinity of trans-Golgi network, the characteristic abnormalities because of protein trafficking defects in HPS1. These ultrastructural features were far more clearly demonstrated in the nevus cells than in the epidermal melanocytes. Thus, ultrastructural analysis of nevus cells may be an additional diagnostic tool for HPS1 and could give us important clues to further understanding of the pathomechanisms of HPS.

Adolescent↗
PubMed1984

Chemical and ultrastructural differences in endotoxic glycolipids from Salmonella minnesota Re mutant extracted with various solvent systems.

Endotoxic glycolipids ( ReGl ) extracted from the whole cells (WC) and cell walls of heptose-less Re mutant of Salmonella minnesota with hot phenol-water (PW), phenol-chloroform-petroleum ether (PCP), and chloroform-methanol (CM) were analyzed chemically and examined with an electron microscope. ReGl -PW-(WC) contained mannose and proteins as contaminants, ReGl -PCP(WC) consisted of an excess amount of amino compound (cadaverine), and ReGl -PCP(WC) consisted of proteins and cadaverine, in addition to the ReGl constituents. The ultrastructure of ReGl -PW(WC) resembled onions when stained with uranyl formate, and was spherical when stained with uranyl acetate, sodium phosphotungstate and ammonium molybdate, whereas those of ReGl -PCP(WC) and ReGl -CM(WC) were shaped like ribbons. However, the shadowed ultrastructures of ReGl -PCP(WC) and ReGl -CM(WC) showed small pieces of flat and wide sheets, respectively. ReGl -PCP(WC) re-extracted by the PW method was found to be converted into the onion-like structure which was similar to that of ReGl -PW(WC), while an intermediate form (fingerprint-like) was observed after re-extraction of ReGl -PW(WC) with PCP. It was strongly suggested that the ultrastructural arrangement of ReGl was dependent on the solvent systems used for extraction.

Alkanes↗
PubMed1992

Ultrastructural immunogold studies in two cases of linear IgA dermatosis. Are there two distinct types of this disease?

It has been suggested that patients with homogeneous linear IgA deposits at the basement membrane zone constitute a distinct bullous disorder called linear IgA dermatosis (LAD) of adults or children. The results of the present ultrastructural immunogold study in two patients with LAD suggest that LAD is not a single disease entity. LAD in a 10-year-old girl was found to be ultrastructurally similar to an IgA-type pemphigoid. IgA was detected in the uppermost lamina lucida underlying the basal cell plasma membrane. In a second patient, an 86-year-old man, IgA deposits were present within the lamina densa and the anchoring plaques. The distribution of IgA in this patient was ultrastructurally identical with that of IgG in epidermolysis bullosa acquisita skin and with that of the non-collagenous globular terminus of collagen VII within the basement membrane zone of normal skin. By using the immunogold technique, we could distinguish two distinct types of LAD according to the IgA binding sites in the diseased skin. We suggest that different labelling patterns may correspond to different clinical pictures.

Aged↗
PubMed1982

Philadelphia chromosome-positive blastic leukaemia: ultrastructural and ultracytochemical evidence of basophil and mast cell differentiation.

Ultrastructural, ultracytochemical, immunologic and biochemical studies were performed on leukaemic cells from 41 patients with Philadelphia chromosome-positive blastic leukaemia; 28 patients were in blast transformation of chronic myelogenous leukaemia and 13 patients presented with 'acute' leukaemia. The patients were divided into two morphologic groups, lymphoid (16 cases) and myeloid (25 cases), on the basis of light microscopy and cytochemistry. All lymphoid cases studied for the presence of CALLA (10 patients) and TdT (11 patients) were positive. Two of 13 myeloid cases studied were TdT positive. The blasts from 10 of 16 lymphoid cases contained immature basophil/mast cell granules on ultrastructural examination. Peroxidase-positive 'lymphoid' blasts were noted in three of seven patients studied by ultracytochemical techniques. The reactivity was primarily confined to granular structures. Of the 25 cases in the myeloid group, blasts from 14 cases showed basophil/mast cell differentiation, nine cases showed neutrophil/monocyte features, and two cases were megakaryoblastic. Distinct patterns of ultrastructural peroxidase positivity were seen in the seven myeloid cases studied. In basophil/mast cell precursors the reactivity was primarily confined to granules; neutrophil precursors showed reactivity in the nuclear envelope, rough endoplasmic reticulum (RER), golgi and granules; in megakaryoblasts, only the nuclear envelope and RER were positive while the granules were consistently negative.

Basophils↗
PubMed1988

The role of ultrastructural cytochemistry and monoclonal antibodies in clarifying the nature of undifferentiated cells in acute leukaemia.

The nature of the cells in 21 cases of acute leukaemia with blasts which were undifferentiated by light microscopy criteria was investigated by immunophenotyping, ultrastructural cytochemistry and DNA analysis. Two groups of cases were recognized. Fourteen cases were negative with B and T lymphoid markers and expressed one or two myeloid antigens detected by the monoclonal antibodies (McAb) MCS2 (CD13) and MY9 (CD33). Peroxidase activity was demonstrated at ultrastructural level by the method of Roels on unfixed cells in eight out of 10 cases; rearrangement of the immunoglobulin (Ig) genes was demonstrated in one of the three cases investigated. These cases are proliferations of early, MO, myeloblasts which can only be recognized by immunological and ultrastructural cytochemical methods. The remaining seven cases revealed a complex phenotype with expression of myeloid and lymphoid antigens. Peroxidase activity was detected in blasts from two cases with rearrangement of the Ig-heavy chain gene; in one of them the T cell receptor beta and gamma chain genes were also found in rearranged configuration. This group comprises cases of biphenotypic and mixed acute leukaemia which probably involve multipotent stem cells. This study demonstrates that the expression of myeloid antigens on blast cells parallels closely the presence of peroxidase activity and that lymphoid markers correlate with gene rearrangements at DNA level. Our findings are reassuring with respect to the specificity of the antimyeloid McAb for the diagnosis of cases which are unclassifiable by conventional methods.

Acute Disease↗