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PubMed2002

High-resolution three-dimensional micro-computed tomography detects bone loss and changes in trabecular architecture early: comparison with DEXA and bone histomorphometry in a rat model of disuse osteoporosis.

RATIONALE AND OBJECTIVES: The ability of three-dimensional micro-computed tomography (3D-microCT) to detect changes in a rat model of disuse osteoporosis was evaluated and compared with two reference techniques: dual x-ray absorptiometry (DEXA) for bone mass, and bone histomorphometry (BHM) for bone mass and trabecular micro-architecture. METHODS: Forty-two rats were divided into controls or were hindlimb unloaded for 7, 13, and 23 days. DEXA bone mineral density measurements were performed on right tibiae. Then, after plastic embedding, bone volume (BV/TV) and trabecular (Tb)-derived parameters of trabecular bone architecture (Tb Th, thickness; Tb N, number) were measured with BHM. 3D-microCT measurements of BV/TV, Tb Th, and Tb N were carried out on left tibiae. RESULTS: Unloaded rats lost bone in a time-dependent manner. DEXA and 3D-microCT detected bone loss earlier than BHM. The decreases in Tb Th and Tb N were observed at day 13 only with 3D-microCT (P < 0.05 and P < 0.01, respectively). All bone mass and architectural parameters measured with the three techniques correlated significantly (0.59, 0.89, P < 0.001), except Tb Th. CONCLUSIONS: 3D-microCT is a valid technique for bone mass and micro-architecture measurements in this rat model of disuse osteoporosis.

Absorptiometry, Photon↗
PubMed1983

Morphometric study of mesenteric and renal arteries in spontaneously hypertensive rats.

Arteries from spontaneously hypertensive rats (SHR), stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto controls (WKY) were fixed by immersion and plastic embedded. The media cross-sectional area and the length of the internal elastic membrane were measured. The ratio between media thickness and internal radius was then calculated for a standardized condition, implying a perfectly smooth and circular internal elastic membrane. An increase of the media to radius ratio was already demonstrable in visceral arterial branches of SHR and SHRSP by 15 days of age, indicating that changes of arterial structure could be of pathogenetic importance in early hypertension. At seven months of age the ratio was significantly increased in mesenteric arterial branches of SHR and SHRSP and in renal arterial branches of SHRSP. The media to radius ratio was markedly increased in the renal and superior mesenteric arterial trunks of adult SHR (P less than 0.001 in both) and SHRSP (P less than 0.001 and P less than 0.01). This was due to a greater media cross-sectional area in the former vessels and to a combination of greater media and reduced radius in the latter.

Animals↗
PubMedDate not supplied

Intestinal mucosa in nephropathic cystinosis.

The major manifestations of nephropathic cystinosis are renal tubular acidosis, vitamin D-resistant rickets, and dwarfism. Cystine crystals are deposited in a variety of cells, mainly phagocytic, including macrophages of the intestinal lamina propria. Previously, ultrastructural changes were suggested to occur in the absorptive epithelium as well, possibly as a result of local cystine toxicity. We report here on the light- and electron-microscopic findings in the jejunal mucosa of two patients, aged 4 and 9 years with nephropathic cystinosis. Cystine crystals were easily identified in semithin sections of plastic-embedded specimens as brick- and hexagon-shaped spaces in macrophages. Electron microscopy showed that all crystals were in single-membrane-limited bodies (lysosomes), within phagocytic cells, and exclusively located in the lamina propria. In contrast to previous findings, the absorptive epithelium showed no abnormalities. We conclude that the growth failure in cystinosis is not a consequence of morphological toxic alterations in the intestinal epithelium, but is related to the known metabolic abnormalities of this condition. The use of rectal suction biopsy as a means of diagnosing cystinosis is also suggested as an alternative to other diagnostic methods.

Biopsy↗
PubMed2000

2000 Volvo Award winner in basic science studies: Exogenous tumor necrosis factor-alpha mimics nucleus pulposus-induced neuropathology. Molecular, histologic, and behavioral comparisons in rats.

STUDY DESIGN: This study tested the hypothesis that the 17-kDa form of tumor necrosis factor-alpha is the pathophysiologic agent expressed by herniated nucleus pulposus in vivo that is primarily responsible for the histologic and behavioral manifestations of experimental sciatica associated with herniated lumbar discs. OBJECTIVE: The authors determined the molecular weight and concentration of active tumor necrosis factor-alpha in rat herniated disc and used exogenous tumor necrosis factor-alpha at the same molecular weight to study its neuropathologic effect on rat nerve root and dorsal root ganglion preparations in vivo. SUMMARY OF BACKGROUND DATA: Expressed by herniated nucleus pulposus in culture, tumor necrosis factor-alpha causes neuropathologic injury in nerve roots and neuropathic pain states in which mechanical allodynia is seen in response to peripheral stimuli. METHODS: Western blotting was used to identify the molecular weight of the operative tumor necrosis factor-alpha protein form, and measures of optical density were used for semiquantitative determination of concentration. Plastic-embedded nerve roots and dorsal root ganglion were used for neuropathologic evaluation, and von Frey stimulation was used to quantify mechanical allodynia. RESULTS: The 17-kDa form of tumor necrosis factor-alpha is expressed by herniated nucleus pulposus at a concentration of approximately 0.48 ng per herniated rat lumbar disc. Exogenous tumor necrosis factor-alpha applied in vivo to rat nerve roots produced neuropathologic changes and behavior deficits that mimicked experimental studies with herniated nucleus pulposus applied to nerve roots. CONCLUSIONS: The data reinforce other evidence that tumor necrosis factor-alpha is involved in mechanisms of neuropathic pain.

Animals↗
PubMed2002

Dexamethasone decreases blood flow in normal nerves and dorsal root ganglia.

STUDY DESIGN: An experimental physiologic and histologic study of dexamethasone effects on peripheral nerves. OBJECTIVE: To characterize the effect of topically applied 0.4% dexamethasone on acute changes in nerve blood flow and subsequent histologic changes in rat sciatic nerve fibers. SUMMARY OF BACKGROUND DATA: Dexamethasone is an anti-inflammatory glucocorticoid used clinically to reduce the neural consequences of inflammation. Several reports of accidental injury to nerves after steroid injections have raised questions about the mechanisms involved in dexamethasone-induced neurotoxic injury. METHODS: Nerve blood flow studies using a laser Doppler flowmeter were conducted in animals with stable temperature and arterial pressure. Dexamethasone 0.4%, 0.1 mL was applied topically to rat sciatic nerve in the following protocol groups: 1) nerve blood flow recording every 5 minutes for 30 minutes, and 2) initial nerve blood flow recording and repeat recording at 4 hours. Three additional animals had 30-minute nerve blood flow recordings in which normal saline was substituted for dexamethasone; these animals were used for control and to assure that the experimental preparation was viable throughout the observational period. Additional groups of two animals each received dexamethasone but were used only for neuropathologic observation at 2, 4, and 6 days after treatment. Neuropathologic studies were conducted on glutaraldehyde-fixed, plastic-embedded tissue. RESULTS: Application of saline to the exposed sciatic nerves did not significantly change nerve blood flow from baseline values. Nerve blood flow values remained constant throughout the observational period. Dexamethasone, however, significantly reduced nerve blood flow in both the 30-minute and 4-hour groups. Some animals showed an initial transient increase in blood flow before nerve blood flow began to steadily decline to the final values reported. Neuropathologic changes were minimal and consisted only of edema and occasional subperineurial activation of Schwann cells. No demyelination or degeneration was seen. CONCLUSION: Dexamethasone causes statistically significant reductions in normal nerve blood flow at 30 minutes and 4 hours after topical application; however, the reduction is on average below the threshold for causing ischemic changes in the structure of peripheral nerve fibers.

Administration, Topical↗
PubMed1979

The lymphatic drainage of the rat prostate and its status as an immunologically privileged site.

Recent suggestions that the rat prostate is an alymphatic, immunologically privileged site stimulated further investigation of its status using a variety of techniques. Fixation of certain organs by vascular perfusion of glutaraldehyde followed by plastic embedding avoids the distortion and stromal reorganization that often obscures evidence of lymphatic vessels in conventional histological preparations. When applied to the rat prostate, this technique revealed small lymphatic vessels at irregular intervals throughout the sparse stroma. Ink injected into the prostate drained from the organ into iliac lymph nodes within 3 to 4 hr. Enlargement of iliac lymph nodes within 1 week after injection of parental strain lymphoid cells into the prostate of F1 rats confirmed the drainage pattern. Ink and lymphoid cell injections into the bladder wall yielded comparable results, although ink reached iliac nodes sooner than it did in prostate injections. Immunological privilege was investigated by determining survival of skin allografts implanted in the prostate. Skin-into-prostate grafts bearing either major or minor histocompatibility antigens were rejected within a few days of similar orthotopic grafts. The inability of the rat prostate to allow significantly prolonged allograft survival as well as its demonstrated lymphatic drainage argues against an immunologically privileged status.

Animals↗
PubMed2004

Examination of the bone-implant interface in experimentally induced osteoporotic bone.

The objective of this study was to explore the hypothesis that osteoporotic-like (OP) conditions have a negative effect on osseointegration (OI) of dental implants. Using an ovariectomized (OVX) rat model, the extent of OI using histologic and histomorphometric analysis (HMA) under a variety of OVX conditions was assessed. Five experimental groups (n = 7 rats per group) were used: 1) OP control, 2) OI control, () OI followed by OVX treatment to induce OP (OI-->OP), 4) OP induction followed by OI (OP-->OI), and 5) OP induction simultaneously with OI (OI = OP). Using undecalcified plastic-embedded cross-sections of the implant site, HMA was performed to determine the percent of bone contact (BC) at the implant-tissue interface and percent of bone area (BA) immediately (1.5-mm diameter) surrounding the implant site. The presence of Bone Sialoprotein (BSP), an important extracellular matrix component of bone, was evaluated using immunohistochemical staining procedures. The implant control resulted in the highest level of OI (BC = 79%; BA = 87%), whereas all groups in which OVX was performed resulted in a significant reduction in BA (70-75%). High levels of BC were observed in established OP conditions (OP-->OI; BC = 79%); however, following OI, induction of OP conditions (OI-->OP) led to a significant reduction in BC (50%). In each of the OP treatment groups, a diminution of cortical bone, increased trabecularization of the host bone site, and loss of staining of BSP was observed. The results of this work indicate that although OI is possible under a variety of OP-like conditions simulating implant placement, the long-term biomechanical stability of implants under these conditions could be compromised and remains unclear. Further research to understand implant use in the complex bone environment under OP-like conditions is encouraged.

Animals↗
PubMed2005

Structure and stability of internodal myelin in mouse models of hereditary neuropathy.

Peripheral neuropathies often result in abnormalities in the structure of internodal myelin, including changes in period and membrane packing, as observed by electron microscopy (EM). Mutations in the gene that encodes the major adhesive structural protein of internodal myelin in the peripheral nervous system of humans and mice--P0 glycoprotein--correlate with these defects. The mechanisms by which P0 mutations interfere with myelin packing and stability are not well understood and cannot be provided by EM studies that give static and qualitative information on fixed material. To gain insights into the pathogenesis of mutant P0, we used x-ray diffraction, which can detect more subtle and dynamic changes in native myelin, to investigate myelin structure in sciatic nerves from murine models of hereditary neuropathies. We used mice with disruption of one or both copies of the P0 gene (models of Charcot-Marie-Tooth-like neuropathy [CMT1B] or Dejerine-Sottas-like neuropathy) and mice with a CMT1B resulting from a transgene encoding P0 with an amino terminal myc-tag. To directly test the structural role of P0, we also examined a mouse that expresses P0 instead of proteolipid protein in central nervous system myelin. To link our findings on unfixed nerves with EM results, we analyzed x-ray patterns from unembedded, aldehyde-fixed nerves and from plastic-embedded nerves. From the x-ray patterns recorded from whole nerves, we assessed the amount of myelin and its quality (i.e. relative thickness and regularity). Among sciatic nerves having different levels of P0, we found that unfixed nerves and, to a lesser extent, fixed but unembedded nerves gave diffraction patterns of sufficient quality to distinguish periods, sometimes differing by a few Angstroms. Certain packing abnormalities were preserved qualitatively by aldehyde fixation, and the relative amount and structural integrity of myelin among nerves could be distinguished. Measurements from the same nerve over time showed that the amount of P0 affected myelin's stability against swelling, thus directly supporting the hypothesis that packing defects underlie instability in "live" or intact myelin. Our findings demonstrate that diffraction can provide a quantitative basis for understanding, at a molecular level, the membrane packing defects that occur in internodal myelin in demyelinating peripheral neuropathies.

Aldehydes↗
PubMed1978

Chromic-acid formaldehyde fixation of nucleic acids of bacteriophage phi6 and infectious bovine rhinotracheitis virus.

Bacteriophage phi6 nucleic acid was present as a torus after chromic acid-formaldehyde-OSO4 fixation and acetone and propylene oxide dehydration. A herpes virus, infectious bovine rhinotracheitis virus, had its DNA mostly as a torus, collapsed in the centre, or as a network, after glutaraldehyde-OSO4 fixation, but in an uncollapsed torus or network formation after chromic acid-formaldehyde-OSO4. This fixative stabilized nucleic acids, allowing acetone dehydration and plastic embedding without collapse of nucleic acid to the centre of the virion.

Chromium↗
PubMed1987

Replication characteristics and core size of intranuclear herpes simplex virus (HSV-1) in genital skin lesions: electronmicroscopy studies of a biopsy from a female patient.

Herpes simplex virus (HSV) type 1 genital infection, leading to ulcerating lesions in a female patient, was studied by electronmicroscopy. Infection had probably been recent, through oro-genital contact with a cold sore on the husband's lip. Cell-culture typing and serological tests indicated that the patient currently had an HSV-1 secondary infection. Aspects studied in a skin biopsy from an ulcerating labium majus were epidermal cell types infected, stages in virus genesis, virus core diameter in intranuclear capsids and extracellular appearance of virus. Different stages in virus genesis, in virus envelope formation and in nuclear and cytoplasmic degeneration were observed in the few remaining, rounded and swollen, epidermal (?) spinosum cells. Their nuclei, some with marginated chromatin, harboured besides dense-cored or empty capsids, electron-dense blobs possibly representing clones of immature virus and falling apart into aggregates of small granules. In other nuclei, large clusters of dense-cored capsids, some distinctly hexagonal in shape, had accumulated in wide gaps in the nuclear membrane whereas remaining nuclear membrane portions were quadruple and often engaged in viral envelope formation. Partially enveloped capsids and naked dense-cored capsids were seen extracellularly indicating their survival outside cells. An occasional virion was present in dermal blood vessel lumina. Measurements of the electron-dense core (nucleoid) of intranuclear capsids in electronmicrographs showed that the HSV-1 core diameter differs very significantly from the core of intranuclear HSV-2 capsids, thus allowing a clear distinction by electronmicroscopy between the two HSV subtypes in plastic-embedded biopsies.

Adult↗
PubMed2003

Enhanced ionic conductivity of polymer electrolytes containing nanocomposite SiO2 particles.

We report a new kind of polyethlene oxide (PEO)-Li based composite polymer electrolyte containing active nanocomposite particles with ethylene carbonate (EC)/propylene carbonate (PC) plasticizers embedded in mesoporous SiO2 (EC/PC-SiO2). A very large enhancement of the ionic conductivity was observed for the PEO-Li/(EC/PC-SiO2) electrolytes. This could be attributed mainly to conducting EC/PC nanochannels in the active nanocomposite particles. This unique mechanism is absent in currently known nanocomposite polymer electrolytes with inert oxide nanoparticles. Both high ionic conductivity and excellent stability of such new nanocomposite polymer electrolytes potentially makes it one of the most promising electrolyte materials.

Journal Article↗
PubMed1980

Photosynthesis of Grass Species Differing in Carbon Dioxide Fixation Pathways: V. RESPONSE OF PANICUM MAXIMUM, PANICUM MILIOIDES, AND TALL FESCUE (FESTUCA ARUNDINACEA) TO NITROGEN NUTRITION.

The response of apparent photosynthesis to N nutrition was studied in the C(3) grass, tall fescue (Festuca arundinacea Schreb.), in the C(4) species Panicum maximum Jacq., and in Panicum milioides Nees ex Trin., a species with characteristics intermediate between C(3) and C(4) photosynthetic types. Plants were grown in culture solution containing 1, 5, 50, and 200 milligrams N per liter. Apparent photosynthesis was measured on the youngest fully expanded leaves at 320 microliters of CO(2) per liter of air and 21% O(2). Leaf conductance was calculated from transpiration measurements, and CO(2) compensation concentrations were also estimated. Several leaf anatomical characteristics were studied on plastic-embedded material. Leaf N content was determined on leaves which were used in photosynthesis measurements.Apparent photosynthesis increased in a linear fashion with increases in leaf N content in all three species. The increase in apparent photosynthesis per unit increase in leaf N was over twice as great in P. maximum (9.7 milligrams CO(2) per square decimeter per hour for each increase of 1% leaf N) as in P. milioides and tall fescue. Apparent photosynthesis and its response to N level were similar in P. milioides and tall fescue, but at leaf N concentrations above 2%, apparent photosynthesis in these two species was only about one-half of that in P. maximum. Increases in apparent photosynthesis due to higher N levels were accompanied by increases in both leaf and mesophyll conductances in P. maximum, whereas in P. milioides and tall fescue only mesophyll conductance was significantly correlated with leaf N. Water use efficiency (apparent photosynthesis/transpiration) increased in a linear manner with increased leaf N in all three species but was more closely related to leaf N in P. milioides and tall fescue than in P. maximum. High N levels tended to increase leaf thickness and interveinal distance in all three species. The percentage of air space in leaf tissue and the mesophyll cell diameter were either not affected or changed only slightly by N nutrition with the exception that percentage of air space in tall fescue leaves rose from 17.3 to 24.8 with an increase in solution N level from 1 to 200 milligrams per liter. Although P. milioides has been shown to have photosynthetic and leaf anatomical characteristics intermediate to C(3) and C(4) species, its response to N was similar to that of the C(3) grass, tall fescue.

Journal Article↗
PubMed2005

An energy-based three-dimensional segmentation approach for the quantitative interpretation of electron tomograms.

Electron tomography allows for the determination of the three-dimensional structures of cells and tissues at resolutions significantly higher than that which is possible with optical microscopy. Electron tomograms contain, in principle, vast amounts of information on the locations and architectures of large numbers of subcellular assemblies and organelles. The development of reliable quantitative approaches for the analysis of features in tomograms is an important problem, and a challenging prospect due to the low signal-to-noise ratios that are inherent to biological electron microscopic images. This is, in part, a consequence of the tremendous complexity of biological specimens. We report on a new method for the automated segmentation of HIV particles and selected cellular compartments in electron tomograms recorded from fixed, plastic-embedded sections derived from HIV-infected human macrophages. Individual features in the tomogram are segmented using a novel robust algorithm that finds their boundaries as global minimal surfaces in a metric space defined by image features. The optimization is carried out in a transformed spherical domain with the center an interior point of the particle of interest, providing a proper setting for the fast and accurate minimization of the segmentation energy. This method provides tools for the semi-automated detection and statistical evaluation of HIV particles at different stages of assembly in the cells and presents opportunities for correlation with biochemical markers of HIV infection. The segmentation algorithm developed here forms the basis of the automated analysis of electron tomograms and will be especially useful given the rapid increases in the rate of data acquisition. It could also enable studies of much larger data sets, such as those which might be obtained from the tomographic analysis of HIV-infected cells from studies of large populations.

Algorithms↗
PubMed1985

An organ culture model for examining epidermal desquamation.

The use of organ cultures of mouse ear skin for examining mechanisms of stratum corneum shedding has been investigated. The formation and loss of stratum corneum cells was assessed by electron microscopic autoradiography and from counts of stratum corneum cell layers taken from sections of plastic-embedded specimens. Using media supplemented with cortisone, there was a linear accumulation of stratum corneum cell layers and the rate of epidermal cell formation corresponded approximately to that in vivo. Cells that accumulated at the stratum corneum surface were loose and could consistently be removed by treatment with detergent and ultrasonication indicating the persistence of shedding mechanisms in vitro.

Animals↗
PubMed1986

Selective binding of colloidal gold-protein conjugates to epidermal phosphorus-rich keratohyaline granules and cornified cells.

Colloidal gold solutions conjugated with staphylococcal protein A (SpA) are widely used in high-resolution immunocytochemical studies to visualize antibodies bound at antigenic sites. Here we report that colloidal gold solutions conjugated with SpA, bovine serum albumin (BSA), or gelatin bind selectively to structures in glutaraldehyde-fixed, plastic-embedded epidermis of rabbit, mouse, and human. Two types of keratohyaline granules are present in epidermis, a phosphorus-rich (PR) and a sulphur-rich (SR) type. The PR keratohyaline granules were strongly labeled with gold particles, whereas SR keratohyaline granules or other structures in the living cells of epidermis were unlabeled. The PR keratohyaline granules are assumed to be precursors of the matrix protein of cornified cells, and intense gold labeling occurred over the lower layer of cornified cells (i.e., stratum lucidum). More superficial cornified cells were weakly labeled or unlabeled. The gold labeling pattern was identical whether SpA, BSA, or gelatin was used to stabilize the colloidal gold solution. The mechanism of binding of protein-conjugated gold to PR keratohyaline granules and matrix protein of cornified cells is not clear. It is speculated that the charged gold particles are not completely coated by the stabilizing protein, allowing for an electrostatic interaction with charged proteins in sections of cells.

Animals↗
PubMed1977

Ultrastructure of the human dermal microcirculation. II. The capillary loops of the dermal papillae.

Electron microscopy was used to define the ultrastructure of the capillary loops in the dermal papillae of normal, eczematous, and psoriatic skin. Capillary loops were reconstructed from 1-mum plastic-embedded sections. Ultrathin sections were taken at 4- to 6-mum intervals for correlation with the thick sections. The capillary loops of normal forearm and elbow skin could be divided into two segments: an intrapapillary and extrapapillary portion. The intrapapillary portion had the ultrastructural characteristics of an arterial capillary--homogeneous-appearing basement membrane without bridged fenestrations. The ascending limb in the extrapapillary portion was also an arterial capillary and the descending limb in the same portion had venous characteristics--multilayered basement membrane. The intrapapillary arterial loop developed venous characteristics abruptly after the vessel left the dermal papilla proper. The capillary loops in acute nummular eczema were identical in ultrastructure to those of normal skin. Bridged fenestrations were found in one capillary loop in eczema but not in normal skin. By contrast, the intrapapillary capillary loops in psoriasis were venous capillaries which were characterized by bridge fenestrations and multilayered basement membrane. The ultrastructural features of the capillary loops and those of the microcirculatory segments in the horizontal dermal plexus should provide sufficient criteria for one to evaluate the nature of vascular abnormalities that occur in the upper dermis.

Adult↗
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

Circulating Sézary cells in the diagnosis of Sézary syndrome (quantitative and morphometric analyses).

Plastic-embedded circulating Sézary cells were examined in semithin and thin sections (assisted by the nuclear contour index-NCI). Eight cases of Sézary syndrome were analyzed as well as 11 controls (3 cases of widespread eczemas and 8 cases of erythroderma), 7 cases of mycosis fungoides, and 3 healthy individuals. Discriminating criteria between Sézary syndrome and benign diseases were sought: in addition to Sézary cells (NCI greater than 6.5) intermediate lymphocytes (5.0 less than NCI less than or equal to 6.5) proved to be helpful. Cases with Sézary syndrome were clearly differentiated when the following 3 ultrastructural criteria were fulfilled: (1) Sézary cells (SC) greater than 9%; (2) intermediate lymphocytes (IL) greater than 20%; (3) the sum of SC and IL greater than 37%. A good correlation between thin and semithin sections was obtained (correlation coefficient for Sézary cells r = 0.82). Usually the values of SC were slightly higher on thin sections. The diagnosis of SS can be made on semithin sections when the ultrastructural criteria are fulfilled. In this way 8 of 12 samples of Sézary syndrome were correctly classified. Therefore, semithin sections (studied by light microscopy) are recommended as a routine method in the diagnosis of cases suspected of Sézary syndrome, whereas thin sections (studied by electron microscopy) appeared to be necessary in problem cases only.

Adult↗