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At least 325 records · Page 18Linked to original sources
PubMed1998

Paraneoplastic demyelinating neuropathy, subacute sensory neuropathy, and anti-Hu antibodies: clinicopathological study of an autopsy case.

A patient with anti-Hu antibodies, small-cell lung carcinoma, and autopsy-proven subacute sensory neuropathy had early slowing of motor and sensory conduction velocities. In the peripheral nerves, chronic demyelinating and remyelinating lesions with axonal degeneration were associated with an inflammatory reaction consisting of CD8+ T cells and CD68+ macrophages. On immunohistochemical testing, the patient's serum did not react with normal nerve, suggesting that the Hu proteins were not the target of the inflammatory reaction in the nerve.

Aged↗
PubMed1996

A two-step embedding process for better preservation of soft tissue surrounding coral implants.

Infiltration of paraffin or embedding polymers proceeds more quickly in soft than in mineralized tissue specimens (bone or biomaterial). The proposed method takes advantage of this difference to protect soft tissue from the action of decalcifying agents. After embedding a bone-soft-tissue sample in a hydrophobic polymer, it is cleared of the resin on one of its sides to permit access of the decalcifying solution to the mineral component. A second infiltration with another polymerizable solution that cures in the empty pores created by the dissolution makes it possible to obtain a homogeneous hard block, make thin slices, and perform enzyme histochemistry and immunostaining on well-preserved soft tissue with most of its antigenic and enzymatic properties intact.

Animals↗
PubMed1997

Osseointegration in cortical sheep bone of calcium phosphate implants evaluated by PIXE method and histology.

Osseointegration of porous calcium phosphate ceramics evolves in several stages once implanted. Histologic analysis has often been used to evaluate the mechanism of integration of this material. Histologic parameters can be completed by physical analysis to obtain a semiquantitative evaluation of the osseointegration process. The histologic observation of hydroxyapatite (HA)-ceramic-containing bone sections was associated with proton-induced X-ray emission (PIXE) analysis and the results obtained by both methods were compared. Porous HA-ceramic cylinders were implanted in cortical bone of sheep femurs for periods ranging from 2 to 36 weeks. Thick sections of the implant containing bone were made at the end of the implantation period. A scanning line with two proton impacts 0.5 mm apart was plotted from the edges of cortical bone across the implanted ceramic and the X-rays produced were determined. Calcium, phosphorus, zinc, strontium, and iron contents were measured. Following PIXE analysis, the sections were surface-stained and observed under a light microscope to define the osseointegration index. Two regions of the curves were identified for each element characterizing either the bone tissue or the ceramic. Zinc and strontium present in the bone tissue but absent from the ceramics appeared after the 8th and the 12th implantation weeks, respectively. Iron present in the implant decreased with time, and calcium and phosphorus contents tended to be the same at the end of the implantation period in both curve regions. Histologic observation showed that immature bone invaded the pores of the outer layer of the ceramic as early as 2 weeks after implantation. Ceramics were totally osseointegrated 20 weeks after implantation. Osseointegration was apparently still evolving as judged by the PIXE method when histologic integration was considered complete.

Animals↗
PubMed1999

Ultrastructure of neuro-spirocyte synapses in the sea anemone Aiptasia pallida (Cnidaria, Anthozoa, Zoantharia).

Using transmission electron microscopy of serially sectioned tentacles from the sea anemone Aiptasia pallida, we located and characterized two types of neuro-spirocyte synapses. Clear vesicles were observed at 10 synapses and dense-cored vesicles at five synapses. The diameters of vesicles at each neuro-spirocyte synapse were averaged; clear vesicles ranged from 49-89 nm in diameter, whereas the dense-cored vesicles ranged from 97-120 nm in diameter. One sequential pair of synapses included a neuro-spirocyte synapse with clear vesicles (81 nm) and a neuro-neuronal synapse with dense-cored vesicles (168 nm). A second synapse on the same cell had dense-cored vesicles (103 nm). An Antho-RFamide-labeled ganglion cell and three different neurites were observed adjacent to spirocytes, but no neuro-spirocyte synapses were present. Many of the spirocytes also were immunoreactive to Antho-RFamide. The presence of sequential neuro-neuro-spirocyte synapses suggests that synaptic modulation may be involved in the neural control of spirocyst discharge. The occurrence of either dense-cored or clear vesicles at neuro-spirocyte synapses suggests that at least two types of neurotransmitter substances control the discharge of spirocysts in sea anemones.

Animals↗
PubMed1980

The role and limitations of frozen section and needle aspiration biopsy in breast cancer diagnosis.

Frozen section of breast biopsy specimens, and cytologic smears of breast mass aspirates, are both acceptable methods in the initial evaluation of palpable breast masses. The latter method is an outpatient procedure without significant morbidity. Interpretation may be made immediately; however, the diagnostic information obtained is limited to "malignant" or "negative." Frozen section may be applied to open biopsy or needle core biopsy specimens. In either case, the false-negative rate is less than that experienced with needle aspiration, and additional information is obtained regarding the histologic characteristic of the neoplasm. Although open biopsy is an operating room procedure, needle core biopsy may be performed in the office; however, local anesthetic is required and the patients do experience more pain than with fine-needle aspiration. The selection of the proper procedure must be individualized, depending on the clinical situation and the amount of diagnostic information required. It is essential to remember that although a positive result may be considered diagnostic, a negative report is always tenuous and should not lead to definitive therapy.

Biopsy↗
PubMed1983

Pitfalls in frozen section diagnosis of malignant melanoma.

The importance of obtaining an intraoperative diagnosis and measurement of thickness of a malignant melanoma has emerged since the change in the surgical approach towards thin melanomas (0.75 mm). In experienced centers, both diagnosis and thickness, can be established on frozen section. Eighty-four pigmented lesions were examined on frozen section. Thirty of 31 were correctly diagnosed as malignant melanomas. The one not diagnosed was a regressing melanoma. The frozen section diagnosis of a regressing melanoma is difficult, and this should be deferred until paraffin sections are examined. In 29 consecutive skin melanomas thickness was measured on frozen section and was found to be 0.1-0.4 mm more than that measured on paraffin sections of the same specimens. It is therefore suggested that tumors measuring up to 0.85 mm on frozen section should be included in the group of thin melanoma.

Diagnostic Errors↗
PubMed1986

Frozen-section diagnosis in surgical pathology. A prospective analysis of 526 frozen sections.

Five hundred eighty-six consecutive frozen-section consultations performed during a 1-year period were studied prospectively in order to assess the accuracy of the method and develop a quality control mechanism. The overall accuracy was 97.1%. The accuracy of the method with breast lesions was 97.9%. Specimens from the gastrointestinal tract and thyroid were incorrectly interpreted in 5% of the cases. The accuracy for lymph node specimens was 96.2%, with more than 50% consulted out of curiosity. The authors conclude that frozen section of lymph node is not recommended. Most of the errors were sampling errors made by the pathologist. The authors therefore conclude that in clinically suspected malignancy, more than one sample must be examined in order to decrease the false-negative diagnosis in frozen section.

Breast Neoplasms↗
PubMed1987

Microscopically oriented histologic surgery for head and neck mucosal cancer.

Frozen section directed surgery, called MOHS, has been successfully utilized in the resection of primary epidermoid tumors of the head and neck. For the 93 cases reviewed in this study, 70% had microscopically identified tumor 1 cm away from clinically evident disease. Tumor spread was along planes of least resistance, most commonly in the submucosa. Microscopically directed excisions were able to trace and remove these tumor extensions. Local control in 93 patients with 2-year follow-up was 91% and, with salvage of recurrences, was 95%. The authors' observations suggest three important concepts. First, epidermoid cancer of the head and neck grows as a continuous neoplasm. Second, this work casts serious doubt on the concept of "field cancerization" or multiple primaries as a cause of local recurrence. Third, conventional frozen section analysis of surgical margins is highly unlikely to discover microscopic extensions because many tumor extensions are thin, finger-like projections which require examination of the entire surgical margin to detect.

Carcinoma, Squamous Cell↗
PubMed1990

Management of superficial squamous cell carcinoma of the lip with Mohs micrographic surgery.

Forty-one patients were treated with Mohs micrographic surgery for well-differentiated superficial squamous cell carcinoma of the lip; 34 had closure of their surgical site by a mucosal advancement flap, and five were allowed to heal by second intention. Cases were limited to T1N0M0 or T2N0M0, these being early superficial lesions. Primary closure by mucosal advancement provides cosmetic and functional healing for these lesions. The combination of Mohs micrographic excision and mucosal advancement closure may be considered standard office or outpatient surgical management of these common tumors.

Adult↗
PubMed2001

Quantitative imaging of tyrosine hydroxylase and calmodulin in the human brain.

The distributions of tyrosine hydroxylase and calmodulin in adult normal postmortem human brain were analyzed quantitatively. Consecutive coronal sections were obtained from the anterior area of the right hemisphere and were stained immunohistochemically for tyrosine hydroxylase and calmodulin. Stained sections were divided into approximately 3 million microareas at 50 microm intervals, and the immunohistochemical fluorescence intensity in each area was measured by a human brain mapping analyzer, which is a microphotometry system for analysis of the distribution of neurochemicals in a large tissue slice. Immunoreactive staining of tyrosine hydroxylase and calmodulin was observed in almost all brain regions, but its intensity varied. Relatively high levels of calmodulin were observed in brain regions with high levels of tyrosine hydroxylase, though high levels of tyrosine hydroxylase were not always observed in brain regions where high levels of calmodulin were distributed. In particular, high levels of both of tyrosine hydroxylase and calmodulin were distributed in the caudate nucleus and putamen. Previously it was shown that tyrosine hydroxylase was activated and dopamine synthesis was enhanced in the neostriatum region in mice and rats by the intracerebroventricular administration of calcium through a calmodulin-dependent system. The present results combined with these previous findings suggest that the activity of tyrosine hydroxylase in the caudate nucleus and putamen of humans may also be regulated by a calcium/calmodulin-dependent system.

Aged↗
PubMed2001

Cytoarchitectonic study of the brain of a perciform species, the sea bass (Dicentrarchus labrax). II. The diencephalon.

The cytoarchitecture of nuclei in the preoptic area, ventral thalamus, dorsal thalamus, epithalamus, hypothalamus, posterior tuberculum, synencephalon, and pretectum and the accessory optic nuclei was analyzed in a perciform teleost, the sea bass Dicentrarchus labrax, by using serial sections stained with cresyl-violet. In general, the cytoarchitecture of the preoptic area, ventral and dorsal thalamus, epithalamus, and synencephalon resembles the histological pattern of other teleosts. However, the parvocellular preoptic nucleus of sea bass has been subdivided into parvocellular and anteroventral parts for morphological and functional reasons. The hypothalamus of the sea bass seems to differ slightly from that of other teleosts. An elaborated lateral tuberal nucleus, with five subdivisions, and three different nuclei around the lateral recesses were recognized. A medial nucleus of the inferior lobe, which has been reported previously in the perciform Sparus aurata, is also present in the hypothalamus of sea bass but has not been described before in another advanced teleost. The organization of the pretectum and the accessory optic system is essentially similar in sea bass to that described in other perciforms with highly developed vision. The migrated portion of the posterior tuberculum of sea bass appears to differ from this region of the diencephalon in other teleosts. In sea bass, three cell masses that have been described previously only in the perciform Sparus aurata have been assigned to the migrated area of the posterior tuberculum. This study will provide the neuroanatomical basis for future morpho-functional studies to be done in the sea bass brain.

Animals↗
PubMed2002

Direct profiling and imaging of peptides and proteins from mammalian cells and tissue sections by mass spectrometry.

Mass spectrometry can be used to map the distribution of targeted compounds in tissue, providing important molecular information in many areas of biological research. Matrix assisted laser desorption/ionization - time of flight - mass spectrometry (MALDI-TOF-MS) is well suited for the analysis of tissue samples with a spatial resolution of about 30 microm for compounds in a mass range from 1000 to over 50 000 Da. Direct analysis of tissue sections requires spotting or coating of the tissue with a matrix compound typically sinapinic acid or other cinnamic acid analogs. A raster of this sample by the laser beam and subsequent mass analysis of the desorbed ions can record molecular intensities throughout the section. The overall process is illustrated by profiling and imaging of mouse epididymis sections where protein activity changes markedly throughout the section.

Animals↗