Shu-Mei Lai

Synaptic relationships between corticocuneate terminals and glycine-immunoreactive neurons in the rat cuneate nucleus.

The present study describes the ultrastructural synaptic relationships between corticocuneate terminals (CCTs) and glycine-immunoreactive (glycine-IR) neurons in the cuneate nucleus of rats using anterograde tract-tracing of wheatgerm agglutinin conjugated with horseradish peroxidase (WGA-HRP) and anti-glycine immunoperoxidase labeling methods. The HRP-labeled CCTs made axodendritic synapses preferentially in the ventral part of the cuneate nucleus near the obex. In a total of 182 CCTs surveyed, 14 of them made direct synaptic contacts with immunoperoxidase-labeled glycine-IR dendrites. The present results suggest that cortical modulation on the sensory transmission of cuneate nucleus may be mediated through glycine-IR neurons.

Three-Dimensional Cytomorphology and Its Relationship with Clinical Stage in Fine Needle Aspiration Biopsy of Papillary Thyroid Carcinoma

OBJECTIVE To elucidate three-dimensional (3-D) cytomorphology and its relationship with clinical stage in fine needle aspiration biopsy (FNAB) of papillary thyroid carcinoma (PTC). STUDY DESIGN FNAB was performed in tumors from 34 patients with PTC. The aspirate was stained and observed under a light microscope (LM). The aspirate was also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). Findings under SEM were correlated with the presentation under LM and also with clinical stage. As a control, FNAB was also performed on a normal part of the thyroid in six patients. RESULTS Under SEM, normal thyroid cells appeared as round, scattered cells or sheets with a uniform honeycomb cellular arrangement. In PTC, cell sheets with uniform nuclear morphology under LM usually showed a uniform cell arrangement and with distinct cell borders under SEM. Cell sheets with nuclear pleomorphism under LM usually showed a more-disorganized arrangement and with indistinct cell borders under SEM. PTC at advanced clinical stages usually presented with a disorganized cell arrangement, indistinct cell borders and loss of microvilli. CONCLUSION 3-D cytomorphology in FNAB of PTC was related to clinical stage and might be a prognostic factor for PTC.

Three-dimensional cytomorphology in fine needle aspiration biopsy of subacute thyroiditis.

OBJECTIVE To elucidate 3-dimensional (3-D) cytomorphology in fine needle aspiration biopsy (FNAB) of subacute thyroiditis. STUDY DESIGN Ultrasound-guided FNAB was performed on the inflamed area of the thyroid from 4 patients with subacute thyroiditis. The aspirates were stained and observed under a light microscope (LM). The aspirates were also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). For transmission electron microscopy (TEM), the specimen was fixed, dehydrated, embedded in an Epon mixture, cut with an ultramicrotome, mounted on copper grids, electron doubly stained with uranium acetate and lead citrate, and observed with TEM. Findings with SEM were correlated with those with LM and TEM. RESULTS Under SEM, 3-D cytomorphology of subacute thyroiditis displayed loss of a uniform, honeycomb cellular arrangement; variation in size; and decrease or shortening of microvilli in follicular cells, which corresponded to varying degrees of cellular degeneration under TEM. Giant cells that were round or ovoid were also noted with SEM. CONCLUSION Loss of a uniform, honeycomb cellular arrangement; variation in size and decrease or shortening of microvilli in follicular cells; and appearance of round or ovoid giant cells were characteristic 3-D cytomorphology findings in FNAB of subacute thyroiditis.

Three-dimensional cytomorphology in fine needle aspiration biopsy of medullary thyroid carcinoma.

OBJECTIVE To elucidate three-dimensional (3-D) cytomorphology in fine needle aspiration biopsy (FNAB) of medullary thyroid carcinoma (MTC). STUDY DESIGN ENAB was performed on tumors from five patients with MTC. The aspirate was stained and observed under a light microscope (LM). The aspirate was also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). For transmission electron microscopy (TEM), the specimen was fixed, dehydrated, embedded in an Epon mixture, cut with an ultramicrotome, mounted on copper grids, electron doubly stained with uranium acetate and lead citrate, and observed with TEM. Findings under SEM were correlated with those under LM and TEM. RESULTS Under SEM, 3-D cytomorphology of MTC displayed a disorganized cellular arrangement with indistinct cell borders in three cases. The cell surface was uneven and had granular protrusions that corresponded to secretory granules observed under TEM. In one case with multiple endocrine neoplasia type IIB, there were abundant granules on the cell surface. In one case of sporadic MTC with multinucleated tumor giant cells and small cells, granular protrusions also were noted on the cell surface. CONCLUSION Granular protrusion was a characteristic finding in FNAB of MTC tinder SEM and might be helpful in the differential diagnosis.

Three-dimensional cytomorphology in fine needle aspiration biopsy of parathyroid lesions.

OBJECTIVE To elucidate three-dimensional (3-D) cytomorphology in fine needle aspiration biopsy (FNAB) of parathyroid lesions. STUDY DESIGN Ultrasound-guided FNAB was performed on parathyroid lesions from 10 patients with hyperparathyroidism. The aspirates were stained and observed under a light microscope (LM). The aspirates were also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). Findings under SEM were correlated with the appearances under LM as well as with serum parathyroid hormone (PTH) concentrations. RESULTS Under LM, nine cases displayed isokaryosis and one case, anisokaryosis. These appearances corresponded to isocytosis or anisocytosis under SEM. Under SEM, 3-D cytomorphology of parathyroid lesions displayed isocytotic, scattered cells in five cases, uniform cellular arrangements in four cases and anisocytotic, scattered cells in one case. The cell surface was rather smooth in five cases. The other five cases had significant granules on the cell surfaces; these all had serum PTH concentrations > or = 268 pg/mL. CONCLUSION 3-D cytomorphology in FNAB of parathyroid lesions was a rather smooth cell surface in cases with low serum PTH and a granular cell surface in cases with significantly increased serum PTH. These characteristics and the absence of microvilli might be helpful in the differential diagnosis between parathyroid and follicular thyroid lesions.

Elevated galanin receptor type 2 primarily contributes to mechanical hypersensitivity after median nerve injury

In this study, we investigated temporal changes in galanin receptor type 2 (GalR2) expression in NF200-, galanin-, neuropeptide Y (NPY)-, and neuronal nitric oxide synthase (nNOS)-like immunoreactive (LI) dorsal root ganglion (DRG) neurons after median nerve chronic constriction injury (CCI), and the effects of GalR2 on c-Fos expression in the cuneate nucleus (CN). Double immunofluorescence labeling methods were used to appraise changes in GalR2 expression in NF200-LI, galanin-LI, NPY-LI, and nNOS-LI DRG neurons after CCI. The von Frey assay was used to assess the efficiency of intraplantar administration of saline, M871 (a GalR2 antagonist), or AR-M1896 (a GalR2 agonist) on neuropathic signs of rats with CCI. The effects of alterations in c-Fos expression were assessed in all treatments. The percentage of GalR2-LI neurons in lesioned DRGs increased and peaked at 1 week after CCI. We further detected that percentages of GalR2-LI neurons labeled for NF200, galanin, NPY, and nNOS significantly increased following CCI. Furthermore, M871 remarkably attenuated tactile allodynia, but the sensation was slightly aggravated by AR-M1896 after CCI. Consequentially, after electrical stimulation of the CCI-treated median nerve, the number of c-Fos-LI neurons in the cuneate nucleus (CN) was significantly reduced in the M871 group, whereas it increased in the AR-M1896 group. These results suggest that activation of GalR2, probably through NPY or nitric oxide, induces c-Fos expression in the CN and transmits mechanical allodynia sensations to the thalamus.