Tracking of Prosaposin, a Saposin Precursor, in Rat Testis

We tracked prosaposin (PSAP), a trophic factor, using an antibody specific to its proteolytic portion and an antibody to sortilin that traffics PSAP only to the lysosome. Immunostaining revealed that PSAP was distributed mainly on the basal side of seminiferous tubules, where many Sertoli cells and pachytene spermatocytes contained PSAP and its distribution differed depending on the stage of the spermatogenic cycle. The PSAP-sortilin complex was sorted to large lysosomes in the basal cytoplasm of Sertoli cells, where it may be processed into saposins. In contrast, in the thinner apical cytoplasm of Sertoli cells, PSAP in small lysosomes was transported to the apical side around sperm heads or into the lumen for secretion. The results of in situ hybridization analyses suggested that immature tubular cells in young animals produce PSAP to self-stimulate proliferation. However, in adults, not only Sertoli cells but also pachytene spermatocytes produce and secrete PSAP around germ cells or into the tubular lumen to stimulate cell proliferation or differentiation in a paracrine or autocrine manner. In summary, PSAP is not only a precursor of lysosomal enzymes but also a pivotal trophic factor in organogenesis in the immature testis and spermatogenesis in the mature testis.

Intratympanic Insulin-like Growth Factor-1 Administration Via the Otic Bulla in a Severe Facial Paralysis Model

HYPOTHESIS

We investigated the treatment effect of intratympanic insulin-like growth factor-1 (IGF-1) on severe facial paralysis in guinea pigs.

BACKGROUND

The use of regenerative medicine involving growth factors has been reported in the treatment of peripheral nerve diseases. IGF-1 plays a crucial role in nerve regeneration.

METHODS

We performed the following procedures on guinea pigs. In the normal group (n = 7), no procedure was performed. In the saline (n = 7) and IGF-1 (n = 7) groups, facial paralysis was induced by freezing of the facial canal. Subsequently, in the saline and IGF-1 groups, a gelatin hydrogel impregnated with 100 μL saline and 400 μg/100 μL IGF-1, respectively, was placed in the facial canal. Facial nerve functions were evaluated using three test batteries: facial movement observation, electrophysiological testing, and histological assessment.

RESULTS

At 10 weeks postoperatively, the facial movement scores for the IGF-1 group were improved compared to those in the saline group. The conductive velocity was significantly faster in the IGF-1 group than in the saline group. There was a significant between-group difference in the nerve fiber number and myelin thickness.

CONCLUSION

Intratympanic IGF-1 administration improved facial nerve regeneration. This novel method could provide prompt ambulatory regenerative treatment and reduce the incidence of poor recovery in patients with severe facial paralysis.

Comparison of the Signal Intensity of Vestibular Schwannoma Between Growing and Nongrowing Tumors

OBJECTIVES/HYPOTHESIS

To determine the relationship between signal intensity on gadolinium (Gd)-enhanced magnetic resonance images and growth of vestibular schwannomas (VSs).

STUDY DESIGN

Cross-sectional study.

METHODS

In this cross-sectional study, we retrospectively reviewed the data of 31 patients with VSs who underwent magnetic resonance imaging (MRI). The mean signal intensities within the regions of interest in the tumor, pons, and temporal muscles were measured on Gd-enhanced T1-weighted MRI. Relative intensity ratios were calculated as follows: T/N pons ratio (T/Np) is the tumor signal intensity/pons signal intensity and T/N muscle ratio (T/Nm) is the tumor signal intensity/temporal muscle signal intensity. Volume measurements were used to assess the tumor size. Growth rate was determined by assessing previous imaging studies. Growing VS was defined as a tumor with a growth rate >100 mm³ /year.

RESULTS

The mean (standard deviation) T/Np and T/Nm were 1.47 (0.27) and 1.50 (0.24), respectively, in nongrowing tumors and 1.78 (0.17) and 1.90 (0.12), respectively, in growing tumors. The T/Np and T/Nm differed significantly between the two groups (T/Np, P < .001; T/Nm, P < .001). Receiver operating characteristic curve analysis showed that cutoffs of 1.56 and 1.76 for T/Np (93.33% sensitivity, 75.00% specificity) and T/Nm (100.00% sensitivity, 93.75% specificity), respectively, could be used to diagnose a growth rate of >100 mm³ /year. The area under the curve was 0.85 (95% confidence interval, 0.70-1.00) for T/Np and 0.94 (0.82-1.00) for T/Nm.

CONCLUSION

Growing VSs show higher signal intensities on Gd-enhanced MRI. Thus, measuring the signal intensity of VS on Gd-enhanced MRI may aid in predicting VS growth.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

The expression of prosaposin and its receptors, GRP37 and GPR37L1, are increased in the developing dorsal root ganglion

Prosaposin (PSAP), a highly conserved glycoprotein, is a precursor of saposins A-D. Accumulating evidence suggests that PSAP is a neurotrophic factor, as well as a regulator of lysosomal enzymes. Recently, the orphan G-protein-coupled receptors GPR37 and GPR37L1 were recognized as PSAP receptors, but their functions have not yet been clarified. In this study, we examined the distribution of PSAP and its receptors in the dorsal root ganglion (DRG) during development using specific antibodies, and showed that PSAP accumulates primarily in lysosomes and is dispersed throughout the cytoplasm of satellite cells. Later, PSAP colocalized with two receptors in satellite cells, and formed a characteristic ring shape approximately 8 weeks after birth, during a period of rapid DRG development. This ring shape, which was only observed around larger neurons, is evidence that several satellite cells are synchronously activated. We found that sortilin, a transporter of a wide variety of intracellular proteins containing PSAP, is strongly localized to the inner side of satellite cells, which contact the neuronal surface. These findings suggest that PSAP and GPR37/GPR37L1 play a role in activating both satellite and nerve cells.

Verbalization, Categorization, and Evaluation of Fundamental Surgical Skills: An Expert Consensus in Open Head and Neck Surgery

Objective

This study aimed to verbalize fundamental surgical skills required for open head and neck surgery (OHNS), to organize them by categorization, and to establish a consensus among surgeons regarding the importance and difficulty of each skill.

Summary Background Data

Improvement of fundamental surgical skills is the core of surgical education; however, surgical skills are not yet organized, and consensus in any surgical field remains uncertain.

Methods

Fundamental surgical skills during OHNS were collected from surgical textbooks, real surgeries, and expert interviews. The items were analyzed to calculate the frequency of words and were categorized by 2 expert surgeons. After consensus on the importance and difficulty of each item was established by 15 expert surgeons using a Delphi survey, principal component (PC) analysis was performed to integrate importance and difficulty into a single parameter.

Results

Sixty skills were verbalized and categorized into 7 categories: "skin flap elevation (n = 6)," "vessel management (n = 9)," "nerve preservation (n = 8)," "instrument handling (n = 11)," "counter traction (n = 7)," "tissue exposure (n = 9)," and "flow and planning (n = 10)." In the Delphi survey, expert consensus was established after 2 voting rounds (Cronbach's α ≥ 0.80). The "counter traction" and "flow and planning" categories had high PC scores, which indicate priority in surgical education.

Conclusion

Fundamental OHNS skills were verbalized, categorized, and evaluated via expert consensus. Assessment of surgeons' skills by the structured items hereby developed will help standardize the quality of OHNS and improve patient outcomes.

Prosaposin and its receptors GRP37 and GPR37L1 show increased immunoreactivity in the facial nucleus following facial nerve transection

Neurotrophic factor prosaposin (PS) is a precursor for saposins A, B, C, and D, which are activators for specific sphingolipid hydrolases in lysosomes. Both saposins and PS are widely contained in various tissues. The brain, skeletal muscle, and heart cells predominantly contain unprocessed PS rather than saposins. PS and PS-derived peptides stimulate neuritogenesis and increase choline acetyltransferase activity in neuroblastoma cells and prevent programmed cell death in neurons. We previously detected increases in PS immunoactivity and its mRNA in the rat facial nucleus following facial nerve transection. PS mRNA expression increased not only in facial motoneurons, but also in microglia during facial nerve regeneration. In the present study, we examined the changes in immunoreactivity of the PS receptors GPR37 and GPR37L1 in the rat facial nucleus following facial nerve transection. Following facial nerve transection, many small Iba1- and glial fibrillary acidic protein (GFAP)-positive cells with strong GPR37L1 immunoreactivity, including microglia and astrocytes, were observed predominately on the operated side. These results indicate that GPR37 mainly works in neurons, whereas GPR37L1 is predominant in microglia or astrocytes, and suggest that increased PS in damaged neurons stimulates microglia or astrocytes via PS receptor GPR37L1 to produce neurotrophic factors for neuronal recovery.

Prosaposin in the rat oviductal epithelial cells

Prosaposin (PSAP) has two forms: a precursor and a secreted form. The secreted form has neurotrophic, myelinotrophic, and myotrophic properties. The precursor form is a precursor protein of saposins A-D. Although the distribution of PSAP in male reproductive organs is well known, its distribution in female reproductive organs, especially in the oviduct, is unclear. Immunoblots and immunohistochemistry of oviducts showed that oviductal tissues contain PSAP proteins, and a significant increase in PSAP was observed in the estrus-metestrus phase compared to the diestrus-proestrus phase in the ampulla. To identify PSAP trafficking in cells, double-immunostaining was performed with antibodies against PSAP in combination with sortilin, mannose 6 phosphate receptor (M6PR), or low-density lipoprotein receptor-related protein 1 (LRP1). PSAP and sortilin double-positive reactions were observed near the nuclei, as well as in the apical portion of microvillous epithelial cells, whereas these reactions were only observed near the nuclei of ciliated epithelial cells. PSAP and M6PR double-positive reactions were observed near the nuclei of microvillous and ciliated epithelial cells. PSAP and M6PR double-positive reactions were also observed in the apical portion of microvillous epithelial cells. PSAP and LRP1 double-positive reactions were observed in the plasma membrane and apical portion of both microvillous and ciliated epithelial cells. Immunoelectron staining revealed PSAP immunoreactive small vesicles with exocytotic features at the apical portion of microvillous epithelial cells. These findings suggest that PSAP is present in the oviductal epithelium and has a pivotal role during pregnancy in providing an optimal environment for gametes and/or sperm in the ampulla.

Pharyngeal metastasis following living-donor liver transplantation for hepatocellular carcinoma: a case report and literature review

Background

The most common sites of recurrence after liver transplantation for hepatocellular carcinoma (HCC) have been reported to be the liver, lung, bone, and adrenal glands, but there have also been many reports of cases of multiple recurrence. The prognosis after recurrence is poor, with reported median survival after recurrence of HCC ranging from 9 to 19 months. Here, we report a case of long-term survival after recurrence of pharyngeal metastasis following living-donor liver transplantation (LDLT) for HCC within the Milan criteria, by resection of the metastatic region and cervical lymph node dissection.

Case presentation

A 47-year-old man with a Model End-stage Liver Disease (MELD) score of 11 underwent LDLT for HCC within the Milan criteria for liver cirrhosis associated with hepatitis B virus infection, with his 48-year-old elder brother as the living donor. One year and 10 months after liver transplantation, he visited a nearby hospital with a chief complaint of discomfort on swallowing. A pedunculated polyp was found in the hypopharynx, and biopsy revealed HCC metastasis. We performed pharyngeal polypectomy. Two years later, cervical lymph node metastasis appeared, and neck lymph node dissection was performed. Although recurrence subsequently occurred three times in the grafted liver, the patient is still alive 12 years and 10 months after recurrence of pharyngeal metastasis. He is now a tumor-free outpatient taking sorafenib.

Conclusion

It is necessary to recognize that the nasopharyngeal region is a potential site of HCC metastasis. Prognostic improvement can be expected with close follow-up, early detection, and multidisciplinary treatment, including radical resection.

Urinary WT1-positive cells as a non-invasive biomarker of crescent formation

OBJECTIVE

The purpose of this study was to assess the relationship between urinary WT1-positive cells (podocytes and active parietal epithelial cells) and WT1-positive cells in renal biopsy to investigate whether urinary WT1-positive cells are useful for detection of crescent formation.

METHODS

Fifty-two patients with kidney disease were investigated (15 cases with crescentic lesions and 37 cases with non-crescentic lesions) for immunoenzyme staining using anti-WT1 antibody for urine cytology and renal biopsy. Numbers of WT1-positive cells in urine and renal biopsy were counted.

RESULTS

There was no correlation between urinary WT1-positive cells and WT1-positive cells in renal biopsy. However, the number of urinary WT1-positive cells in patients with crescentic lesions was significantly higher than in patients with non-crescentic lesions. In addition, the best cut-off value to detect patients with crescentic lesions using urinary was 5 cells/10-mL (area under the concentration-time curve=0.735).

CONCLUSIONS

The results of our study suggest urinary WT1-positive cells can be used to detect patients with crescent formation using 5 cells/10-mL cutoff value. WT1-positive glomerular podocytes and parietal epithelial cells may be shed into urine in active glomerular disease. This study, investigating the relationship between WT1-positive cells in urine and in the renal biopsy found no correlation; however, the results do suggest that, using a cutoff value of 5 cells/10 mL, WT1 positive urinary cells can be used to detect patients with crescent formation.

A prosaposin-derived Peptide alleviates kainic Acid-induced brain injury

Four sphingolipid activator proteins (i.e., saposins A–D) are synthesized from a single precursor protein, prosaposin (PS), which exerts exogenous neurotrophic effects in vivo and in vitro. Kainic acid (KA) injection in rodents is a good model in which to study neurotrophic factor elevation; PS and its mRNA are increased in neurons and the choroid plexus in this animal model. An 18-mer peptide (LSELIINNATEELLIKGL; PS18) derived from the PS neurotrophic region prevents neuronal damage after ischemia, and PS18 is a potent candidate molecule for use in alleviating ischemia-induced learning disabilities and neuronal loss. KA is a glutamate analog that stimulates excitatory neurotransmitter release and induces ischemia-like neuronal degeneration; it has been used to define mechanisms involved in neurodegeneration and neuroprotection. In the present study, we demonstrate that a subcutaneous injection of 0.2 and 2.0 mg/kg PS18 significantly improved behavioral deficits of Wistar rats (n = 6 per group), and enhanced the survival of hippocampal and cortical neurons against neurotoxicity induced by 12 mg/kg KA compared with control animals. PS18 significantly protected hippocampal synapses against KA-induced destruction. To evaluate the extent of PS18- and KA-induced effects in these hippocampal regions, we performed histological evaluations using semithin sections stained with toluidine blue, as well as ordinal sections stained with hematoxylin and eosin. We revealed a distinctive feature of KA-induced brain injury, which reportedly mimics ischemia, but affects a much wider area than ischemia-induced injury: KA induced neuronal degeneration not only in the CA1 region, where neurons degenerate following ischemia, but also in the CA2, CA3, and CA4 hippocampal regions.

[A retrospective study on parotid carcinoma]

We retrospectively analyzed the clinicopathological factors affecting survival in patients with previously untreated parotid carcinoma. The subjects were 50 patients treated in our department from 1987 through 2011. The T stage was T1, T2, T3, and T4 in 4 patients, 11 patients, 9 patients, and 26 patients, respectively. The N stage was N0, N1, and N2 in 36 patients, 3 patients, and 11 patients, respectively. The clinical stage was I, II, III, and IV in 4 patients, 10 patients, 7 patients, and 29 patients, respectively. Histopathologically, eleven tumor types were observed; mucoepidermoid carcinoma was the most common. The overall 5-year survival rate was 72.1%, and the disease-specific 5-year survival rate was 74.0% in 42 patients who received radical surgery. Twelve patients relapsed; the site of relapse was the primary site alone in 2, in the neck alone in 3 patients, in the neck with distant metastases in 2 patients, and in distant metastatic site (s) alone in 5 patients. Univariate analysis showed that significant prognostic factors for overall survival rates were the T stage, cervical lymph node metastasis, clinical stage, grade, facial nerve palsy, and tumor size. We concluded that patients at high risk of recurrence should receive adjuvant therapy to improve the therapeutic outcomes.

Prosaposin-derived peptide alleviates ischaemia-induced hearing loss

CONCLUSION

An 18-mer peptide derived from the neurotrophic region of prosaposin (PS-pep) prevents hearing loss and cochlear damage due to transient cochlear ischaemia by activating an anti-apoptotic pathway. PS-pep is a potent candidate molecule for alleviating ischaemia-induced hearing loss.

OBJECTIVE

PS-pep was investigated for its protective effects against ischaemia-induced hearing loss and cochlear damage.

METHODS

Ischaemia was induced in both cochleae in Mongolian gerbils by pulling the ligatures around both vertebral arteries in an anterior direction using 5 g weights for 15 min. PS-pep was synthesized artificially and administered subcutaneously four times after the induction of transient cochlear ischaemia.

RESULTS

An increase in the auditory brainstem response threshold was alleviated in animals treated with 2.0 mg/kg PS-pep. Histological examinations conducted on day 7 showed that the loss of inner hair cells (IHCs) was more prominent than that of outer hair cells. Higher doses of PS-pep significantly alleviated IHC loss. An increase in the anti-apoptotic factor bcl-2 was also noted in the IHCs treated with PS-pep.

Distribution of prosaposin in rat lymphatic tissues

Prosaposin (PSAP) is as a trophic factor and an activator protein for sphingolipid hydrolase in lysosomes. We generated a specific antibody to PSAP and examined the spatiotemporal distribution of PSAP-immunoreactive (PSAP-IR) cells in the lymphatic tissues of Wistar rats. Immunoblots of tissue homogenates separated electrophoretically showed a single band for PSAP in brain but two bands in spleen. PSAP-IR cells were distributed in both the red and white pulp of the spleen, in both the cortex and medulla of the thymus and in mesenteric lymph nodes. Many PSAP-IR cells were found in the dome portion of Peyer's patches and the number of PSAP-IR cells increased with the age of the rat. To identify the PSAP-IR cells, double- and triple-immunostainings were performed with antibodies against PSAP, CD68 and CD1d. The large number of double- and triple-positive cells suggested that antigen-presenting cells contained much PSAP in these lymphatic tissues. Intense expression of PSAP mRNA, examined by in situ hybridisation, was observed in the red pulp and corona of the spleen. In rats, the PSAP gene generates two alternative splicing forms of mRNA: Pro+9 containing a 9-base insertion and Pro+0 without the insertion. We examined the expression patterns of the alternative splicing forms of PSAP mRNA in the spleen. The presence of both types of mRNA (Pro+9 and Pro+0) indicated that the spleen contains various types of prosaposin-producing and/or secreting cells. These findings suggest diverse functions for PSAP in the immune system.

Lectin binding pattern of gastric mucosa of pacific white-sided dolphin, Lagenorhynchus obliquidens

The stomach of the Pacific white-sided dolphin is divided into three parts: forestomach, proper gastric gland portion, and pyloric chamber. The histological features of the dolphin stomach are similar to those of terrestrial mammal stomachs, although the distribution of glycoconjugates in mucosal cells of the dolphin stomach is unknown. To learn about glycoconjugates in cetacean gastric mucosa, the glycoconjugate distribution in the mucous epithelium of the Pacific white-sided dolphin was studied using 21 lectins. Among the lectins tested, GSL-I and DBA specifically labelled the superficial layer of the forestomach epithelium. GSL-I, SBA, RCA-I, VVA, GSL-II, DSL, LEL, STL, s-WGA, WGA, PNA, and Jacalin labelled the luminal surface of the chief cells in the proper gastric gland. GSL-I, SBA, RCA-I, DSL, LEL, STL, s-WGA, PNA, and LCA labelled tubular structures in the cytoplasm of parietal cells. The surface portion of the pits in the pyloric chamber strongly reacted with RCA-I, GSL-II, WGA, PNA, LCA, PHA-L, and UEA-I, whereas the neck portion reacted weakly. Although lining one tubular portion, individual secretory cells in the pyloric gland displayed a heterogeneous reaction. This is the first report on the lectin histochemistry of a cetacean stomach and reveals GSL-I and DBA as specific marker lectins for the cornified stratified squamous epithelium cells of the Pacific white-sided dolphin. The stomachs of cetaceans and terrestrial mammals have similar histological features and mucous glycoconjugate content.

Sensory tract abnormality in the chick model of spina bifida

Spina bifida aperta (SBA) is an open neural tube defect that occurs during the embryonic period. We created SBA chicks by incising the roof plate of the neural tube in the embryo. The area of the dorsal funiculus was smaller in the SBA chicks than in the normal controls. Additionally, the SBA group had fewer nerve fibres in the dorsal funiculus than the normal controls. The pathway of the ascending sensory nerves was revealed by tracing the degenerated nerve fibres using osmification. We cut the sciatic nerve (L5) of the control and SBA chicks at the central end of the dorsal root ganglion 1 day after hatching and fixed the tissue 3 days later. Degenerated sensory nerve fibres were observed in the ipsilateral dorsal funiculus in the control chicks. In contrast, degenerated sensory nerve fibres were observed in the ipsilateral and contralateral dorsal, ventral and lateral funiculi of the spinal cord in the SBA chicks. Consequently, fewer sensory nerve fibres ascended to the thoracic dorsal funiculus in the SBA chicks than in the normal controls. This is the first report of abnormal changes in the ascending sensory nerve fibres in SBA.

Lectin histochemistry of respiratory mucosa in the Pacific white-sided dolphin

Sugars in the glycocalyx play an important role in the attachment of infectious agents to the respiratory mucosa. We examined the histochemistry of 23 lectins to survey the sugar expression in the glycocalyx of the respiratory mucosa of the Pacific white-sided dolphin, Lagenorhynchus obliquidens. The ciliated and basal cells were positive for all of the lectins studied. SBA, WFA, GSL-II, STL, S-WGA, and PNA staining in the cytoplasm showed different intensities between basal cells and ciliated cells. These results suggest that multiple terminal glycosylation occurs on ciliated and basal cells, such as GalNAc, GlcNAc, NeuNAc, galactose, glucose/mannose, oligosaccharide, and fucose, and that sugar residue expression changes during cell differentiation. The Pacific white-sided dolphin respiratory mucosa might express multiple sugar residues in the glycocalyx, to prevent the attachment and colonisation of infectious agents.

Basic fibroblast growth factor combined with biodegradable hydrogel promotes healing of facial nerve after compression injury: an experimental study

CONCLUSION

Topical application of basic fibroblast growth factor (bFGF) hydrogel facilitates faster healing from traumatic facial paralysis due to continuous release of bFGF.

OBJECTIVES

bFGF is considered a potent agent to facilitate recovery from neuronal damage; however, exogenously applied bFGF does not work well because of its short acting time. To enhance the effects in vivo, we developed a new drug delivery system by embedding bFGF in a gelatin hydrogel that degrades slowly. In this study, the effects of bFGF-hydrogel on traumatic facial nerve paralysis were investigated in guinea pigs.

METHODS

The intratemporal facial nerve was exposed and clamped at the vertical portion using micro needle forceps. The animals were then subjected to one of the following three procedures: group A, no further treatment; group B, one-shot application of bFGF to the nerve; and group C, application of bFGF-hydrogel instead. Six weeks later, facial nerve functions were evaluated by three test batteries: observation of facial movements, electrophysiological testing, and histological study.

RESULTS

The results for groups A and B were similar in the three tests, indicating that one-shot application of bFGF did not benefit facial nerve recovery. In contrast, group C achieved better results in all tests.

[The effects of a novel local ventilation system to reduce the health hazard to students during gross anatomy courses]

Formaldehyde or formalin is indispensable not only as a preservative but also as a disinfectant of cadavers for gross anatomy. It has recently attracted a great deal of attention as a health hazard for students and lecturers. To reduce the concentration of formaldehyde gas (FAG), we improved a novel local ventilation system of the push-pull type. This is the first report dealing with the effects of this ventilation system on the health of students before (over 1 ppm) and after (0.1 ppm) the installation. The percentages of students with lacrymal symptoms or airway irritation were reduced to a third of what they were before the installation. In particular, the number of those with continuously strong symptoms was reduced to a sixth of the pre-installation levels. This local ventilation system draws in fresh air from outside, and directs it to the breathing zone of the students, effectively reducing their symptoms.

One-step nucleic acid amplification for detecting lymph node metastasis of head and neck cancer

6028

Background: Lymph node stage is an important prognostic factor in squamous cell carcinoma of the head and neck (SCCHN). We previously reported the clinical usefulness of sentinel lymph node (SLN) biopsy diagnosed by concurrently performing histological examination using semiserial sections and genetic analysis by quantitative RT-PCR. However, these methods took about 3 hours. In this study, we have attempted to develop a more efficient method for intraoperative genetic detection of lymph node metastasis in SCCHN. Methods: A total of 291 lymph nodes (59 patients) resected on SLN biopsy for cN0 SCCHN or neck dissection for cN1/2 SCCHN were diagnosed by one-step nucleic acid amplification (OSNA) method using GD-100. The primary site was tongue, gingiva, oral floor, buccal mucosa, and pharynx in 44% (26), 37% (22), 10% (6), 5% (3), and 3% (2), respectively. OSNA consists of a short homogenization step followed by amplification of cytokeratin 19 (CK19) mRNA directly from the lysate. It is characterized by the use of 4 different primers specifically designed to recognize 6 distinct regions, so the CK19 primers do not amplify the known CK19 pseudogenes. The reaction process proceeds at a constant temperature (65°C) during strand displacement reaction. Amplification and detection of CK19 mRNA can be completed in a single step. Each lymph node was divided into two halves to diagnose metastasis. An alternative half was used for the OSNA assay with cytokeratin 19 (CK19) mRNA, and the remaining block was subjected to semiserial sectioning, sliced at 200-μm intervals and then examined by H&E and cytokeratin AE1/AE3 immunohistochemical staining. Results: Fifty-four of 291 lymph nodes were pathologically metastasis-positive. The optimal cut-off for the copy number of CK19 mRNA in assessing lymph node metastasis was 300 copies/μl, which had the highest diagnostic accuracy. The sensitivity and specificity of OSNA assay with CK19 mRNA was 92.6% (50/54) and 97% (230/237), respectively. An overall concordance rate between the OSNA assay and histopathology was 96.2%. The OSNA assay could be completed within 30 minutes. Conclusions: The OSNA assay showing high sensitivity and specificity can be used as a novel genetic detection tool of lymph node metastasis in SCCHN patients.

No significant financial relationships to disclose.

Herpes simplex virus type 1 accumulation, envelopment, and exit in growth cones and varicosities in mid-distal regions of axons

The mechanism of anterograde transport of alphaherpesviruses in axons remains controversial. This study examined the transport, assembly, and egress of herpes simplex virus type 1 (HSV-1) in mid- and distal axons of infected explanted human fetal dorsal root ganglia using confocal microscopy and transmission electron microscopy (TEM) at 19, 24, and 48 h postinfection (p.i.). Confocal-microscopy studies showed that although capsid (VP5) and tegument (UL37) proteins were not uniformly present in axons until 24 h p.i., they colocalized with envelope (gG) proteins in axonal varicosities and in growth cones at 24 and 48 h p.i. TEM of longitudinal sections of axons in situ showed enveloped and unenveloped capsids in the axonal varicosities and growth cones, whereas in the midregion of the axons, predominantly unenveloped capsids were observed. Partially enveloped capsids, apparently budding into vesicles, were observed in axonal varicosities and growth cones, but not during viral attachment and entry into axons. Tegument proteins (VP22) were found associated with vesicles in growth cones, either alone or together with envelope (gD) proteins, by transmission immunoelectron microscopy. Extracellular virions were observed adjacent to axonal varicosities and growth cones, with some virions observed in crescent-shaped invaginations of the axonal plasma membrane, suggesting exit at these sites. These findings suggest that varicosities and growth cones are probable sites of HSV-1 envelopment of at least a proportion of virions in the mid- to distal axon. Envelopment probably occurs by budding of capsids into vesicles with associated tegument and envelope proteins. Virions appear to exit from these sites by exocytosis.

Leg dysfunctions in a hatched chick model of spina bifida aperta

We created chicks with spina bifida aperta (SBA) by incising the roof plate of the neural tube of embryos at Hamburger and Hamilton stage 18 or 19. Incision over the length of three somites caused spina bifida occulta (SBO)-like malformation in 47% of the hatchlings. Incision over the length of five and seven somites caused SBA-like malformation in 100% of the hatchlings. The SBO chicks exhibited no symptoms, whereas the SBA chicks exhibited paralysis of a leg muscle and imbalance between an agonist and an antagonist leg muscles. Lesions in these SBA chicks were located in the spinal segments that give rise to motor neurons that innervated the dysfunctional muscles. Histological analysis revealed that there were fewer small spinal neurons (interneurons) at the site of the lesion in SBA chicks than in the normal chicks and that there was no such difference in the number of the large spinal neurons (motor neurons). Leg dysfunctions in this model of SBA may be attributable to the smaller number of interneurons in the spinal segments that contain motor neurons that innervate the dysfunctional muscle. This model may facilitate studies of the pathological mechanisms that lead to leg dysfunctions in SBA chicks.

Changes in expression of prosaposin in the rat facial nerve nucleus after facial nerve transection

Prosaposin is the precursor of saposins A, B, C and D, which are activators of sphingolipid hydrolases. In addition, unprocessed prosaposin functions as a neurotrophic factor in the central and peripheral nervous systems by acting to prevent neuronal apoptosis, to elongate neurites and to facilitate myelination. In this study, the expression pattern of prosaposin in the facial nerve nucleus after facial nerve transection was examined by immunohistochemistry and in situ hybridization. Prosaposin immunoreactivity in the neurons on the operated side facial nerve nucleus showed a biphasic pattern: it was significantly increased on day 3 after transection, decreased dramatically on day 7, started to increase gradually on day 14 and reached another peak on day 21 after transection. Significant increases in the levels of prosaposin mRNA were identified in the neurons on the operated side, suggesting that prosaposin was synthesized vigorously by the neurons themselves in the case of facial nerve transection. The diverse changes in prosaposin immunoreactivity during the process of facial nerve regeneration may reflect the diverse neurotrophic activities of prosaposin in facial motoneurons.

Role of T-lymphocyte subsets in facial nerve paralysis owing to the reactivation of herpes simplex virus type 1

CONCLUSION

Although both T-cell subsets are essential for inhibiting HSV-1 reactivation in the GG, CD4 + T cells play a more important role in host defense against virus replication.

OBJECTIVE

To elucidate the host immunological factors that participate in herpes simplex virus type 1 (HSV-1) reactivation in the geniculate ganglia (GG) and lead to facial paralysis, we developed a mouse model of facial paralysis that involved the reactivation of HSV-1 following general immune suppression.

MATERIAL AND METHODS

Eight weeks after recovery from primary facial paralysis caused by inoculating the auricle with HSV-1 the auricle was scratched and mice (n = 69) were given an i.p. injection of either anti-CD4 (n = 46) or anti-CD8 (n = 23) monoclonal antibody to deplete specific T-lymphocyte subsets. Following this reactivation procedure, the rate of recurrent facial paralysis was compared between the two models. The GG were examined histopathologically and using polymerase chain reaction to detect HSV-1 DNA.

RESULTS

Facial paralysis developed in 42% of mice in the anti-CD4 model and in 13% in the anti-CD8 model. HSV-1 DNA was detected in 50% of the mice in both models. Histopathologically, neurons were destroyed in parts of the GG and numerous virus particles were seen in the surviving neurons.

Phylogenetic investigation of Dogiel's pericellular nests and Cajal's initial glomeruli in the dorsal root ganglion

Cajal's initial glomeruli (IG) and Dogiel's pericellular nests (PCNs) were first described from methylene blue preparations of healthy animal tissues around the beginning of the last century. Since that time, although many reports have been published concerning these structures, few have focused on their development and phylogeny in healthy animals. The aim of this study was to examine the phylogenetic development of the sensory neurons in Cajal's IG (also called axonal glomeruli) and Dogiel's PCNs in the dorsal root ganglion (DRG) of the healthy adult frog, chick, rat, and rabbit. The three-dimensional architecture of the neurons was observed in ganglia by scanning electron microscopy after removal of the connective tissue. The neurons in the DRG of fish are known to be bipolar, but DRG neurons in the species examined here were found to be pseudounipolar, with single stem processes. The proportion of neurons having IG or PCNs increased with increasing phylogenetic complexity in the species examined here. Cajal's initial glomeruli, the convolution of the stem process near the parent cell body: In frogs, the ganglia were small and the neuronal stem processes were very short and straight. In chicks, the stem processes were longer; sometimes very long, tortuous processes were observed. However, no neurons with typical IG were observed in either species. Typical IG were observed in rats and rabbits; their occurrence was much more frequent in rabbits. Pseudounipolarization, i.e., the transition from bipolar to pseudounipolar neurons, is thought to save space, limit the length of neuronal processes, and reduce conduction time. However, an explanation of the evolutionary advantage of the IG, which is formed by the excessive prolongation of the stem process, remains elusive. The cytological and electrophysiological importance of IG has been discussed. Dogiel's pericellular nests (PCNs), which resemble balls of yarn made of thin unmyelinated nerve fibers around DRG neurons, have been observed in the DRG of rats and rabbits, but not in frogs or chicks. This interesting structure shows not only ontogenetic development in healthy animals but also phylogenetic development among species. The nerve fibers in the PCNs were less than 1.2 mum in diameter and had some varicosities. An immunohistochemical study using anti-tyrosine hydroxylase (TH) antibody revealed that some PCNs contain TH-positive nerve fibers and varicosities. Such TH-positive PCNs disappear after sympathectomy. These results suggest that the PCNs are made up of autonomic nerve fibers.

Efficacy of Early Treatment of Bell's Palsy With Oral Acyclovir and Prednisolone

OBJECTIVE

To investigate the therapeutic effects of acyclovir and prednisolone in relation to the timing of treatment in Bell's palsy.

STUDY DESIGN

This was a retrospective study of 480 Bell's palsy patients who were treated with oral acyclovir and prednisolone (94 cases) or prednisolone alone (386 cases).

PATIENTS

Patients met the after criteria: (1) severe or complete Bell's palsy with a score lower than 20 on the 40-point Yanagihara facial score and (2) treatment started within 7 days after onset. The patients were treated with oral prednisolone (60-40 mg/day) with or without oral acyclovir (2,000 mg/day).

MAIN OUTCOME MEASURE

Rate of recovery, which was defined as a facial score of 36 or more, and the absence of contracture with synkinesis.

RESULTS

The overall recovery rate of patients treated with acyclovir and prednisolone was 95.7 percent, which was better than that of patients treated with prednisolone alone (88.6%). The recovery rate in patients who began the combined therapy within 3 days of the onset of palsy was 100 percent and early treatment resulted in early remission. In contrast, the recovery rate in patients who started the combined therapy more than 4 days after onset was 86.2 percent.

CONCLUSION

These results suggest that early diagnosis and treatment within 3 days of the onset of paralysis are necessary for maximal efficacy of combined acyclovir and prednisolone therapy for Bell's palsy.

Lectin histochemical study on the olfactory organ of the newt, Cynops pyrrhogaster, revealed heterogeneous mucous environments in a single nasal cavity

Expression patterns of glycoconjugates were examined by lectin histochemistry in the nasal cavity of the Japanese red-bellied newt, Cynops pyrrhogaster. Its nasal cavity consisted of two components, a flattened chamber, which was the main nasal chamber (MNC), and a lateral diverticulum called the lateral nasal sinus (LNS), which communicated medially with the MNC. The MNC was lined with the olfactory epithelium (OE), while the diverticulum constituting the LNS was lined with the vomeronasal epithelium (VNE). Nasal glands were observed beneath the OE but not beneath the VNE. In addition, a secretory epithelium was revealed on the dorsal boundary between the MNC and the LNS, which we refer to as the boundary secretory epithelium (BSE) in this study. The BSE seemed to play an important role in the construction of the mucous composition of the VNE. Among 21 lectins used in this study, DBA, SBA and Jacalin showed different staining patterns between the OE and the VNE. DBA staining showed remarkable differences between the OE and the VNE; there was intense staining in the free border and the supporting cells of the VNE, whereas there was no staining or weak staining in the cells of the OE. SBA and Jacalin showed different stainings in the receptor neurons for the OE and the VNE. Furthermore, UEA-I and Con A showed different stainings for the nasal glands. UEA-I showed intense staining in the BSE and in the nasal glands located in the ventral wall of the MNC (VNG), whereas Con A showed intense staining in the BSE and in the nasal glands located in the dorsal and medial wall of the MNC (DMNG). The DMNG were observed to send their excretory ducts into the OE, whereas no excretory ducts were observed from the VNG to the OE or the VNE. These results suggested that the secretion by the supporting cells as well as the BSE and the DMNG establishes that there are heterogeneous mucous environments in the OE and the VNE, although both epithelia are situated in the same nasal cavity.

Effects of acyclovir on facial nerve paralysis induced by herpes simplex virus type 1 in mice

OBJECTIVES

Bell's palsy has recently been claimed to be caused by herpes simplex virus type 1 (HSV-1) infection. The anti-viral agent acyclovir is a specific inhibitor of herpesvirus replication, and the most effective agent for the treatment herpesvirus infection. The purpose of this experiment was to assess the effect of acyclovir on the facial nerve paralysis included by HSV-1 infection.

METHODS

We succeeded in producing an animal model of acute and transient facial nerve paralysis induced with HSV-1 neuritis simulating human Bell's palsy. In this study, acyclovir administration was performed before and after facial nerve paralysis, and continued for 5 days. Controls were given phosphate-buffer saline (PBS) instead of acyclovir, and the incidence and duration of facial nerve paralysis was compared in the acyclovir groups and controls.

RESULTS

The incidence of facial nerve paralysis was significantly lower in the group given acyclovir before the paralysis than in the controls, and the duration of facial nerve paralysis was shorter.

CONCLUSIONS

Administration of acyclovir before the paralysis reduced the incidence and duration of facial nerve paralysis. Administration of acyclovir after the paralysis improved the duration of facial nerve paralysis.

Anomalous flexor of the little finger

We report an anomalous palmar muscle belly of the flexor digitorum superficialis muscle (FDS) in the right hand of an 80-year-old female cadaver. The muscle originated from the center of the volar surface of the flexor retinaculum and inserted onto the palmar aspect of the base of the middle phalanx of the little finger. Its tendon of insertion divided into two bands, a pattern typical of the FDS tendon, between which the tendon of flexor digitorum profundus muscle to the little finger passed. The tendon of the usual antebrachial FDS to the little finger was absent. The anomalous muscle belly was innervated by a branch from the median nerve.

Demyelination associated with HSV-1-induced facial paralysis

In 1995, we developed an animal model of transient homolateral facial nerve paralysis by inoculating Herpes simplex virus type 1 (HSV-1) into the auricle of mice. This study examined the mechanism of facial nerve paralysis in this model histopathologically. Using the immunofluorescence technique with anti-HSV-1 antibody, the time course of viral spread and the site of viral replication were investigated over the entire course of the facial nerve. Furthermore, viral replication and nerve degeneration at the site of viral replication were observed by electron microscopy. On the 7th day after inoculation, facial paralysis was observed in more than 60% of mice. Immunofluorescence study revealed HSV-1 in the geniculate ganglion, the descending root, and the facial nucleus at this stage. On the 9th day, the descending root in the sections stained with osmium looked pale, because prominent demyelination had occurred in this region; electron micrographs showed many degenerated oligodendrocytes and large naked axons. In contrast, the facial nucleus neurons showed no remarkable degeneration, despite HSV-1 particles in their cytoplasm. From these findings, we concluded that facial nerve paralysis in this model is caused mainly by facial nerve demyelination in the descending root.

Pathophysiology of facial nerve paralysis induced by herpes simplex virus type 1 infection

Herpes simplex virus type 1 (HSV-1) has been proven to be a cause of Bell's palsy; however, the underlying pathophysiology of the facial nerve paralysis is not fully understood. We established a mouse model with facial nerve paralysis induced by HSV-1 infection simulating Bell's palsy and investigated the pathophysiology of the facial nerve paralysis. The time course of the R1 latency in the blink reflex tests paralleled the recovery of the facial nerve paralysis well, whereas electroneurographic recovery tended to be delayed, compared to that of the paralysis; these responses are usually seen in Bell's palsy. On histopathologic analysis, intact, demyelinated, and degenerated nerves were intermingled in the facial nerve in the model. The similarity of the time course of facial nerve paralysis and the electrophysiological results in Bell's palsy and the model strongly suggest that the pathophysiological basis of Bell's palsy is a mixed lesion of various nerve injuries.

Morphogenetic activity of extracellular matrices on cultured podocytes. Laminin accelerates podocyte process formation in vitro

Morphogenetic effects of various extracellular matrix proteins on the renal podocyte were investigated using the conditionally immortalized podocyte cell line. Podocytes were plated on glass coverslips and coated with the following matrix proteins: laminin-10/11, laminin-1, fibronectin, collagen type IV, collagen type I. Three hours after plating, podocytes on laminins developed prominent processes, while those on other matrix proteins started to elongate processes after two days. Vinculin-immunolabeling showed that podocytes plated on laminins possessed thin rod-shaped focal contacts, whereas those on fibronectin showed large dot-shaped focal contacts. Inhibition of serine/threonine protein kinases induced podocyte process formation in an extracellular matrix-independent manner. The present study reveals the significance of laminin on podocyte morphogenesis in vitro, and shows that different extracellular matrix proteins trigger different intracellular signals governing podocyte morphogenesis. Taken together with our previous studies, podocyte process formation is thought to be regulated by protein Ser/Thr phosphorylation.

Telepsychiatry: assessment of televideo psychiatric interview reliability with present- and next-generation internet infrastructures

OBJECTIVE

We assessed the reliability of remote video psychiatric interviews conducted via the internet using narrow and broad bandwidths.

METHOD

Televideo psychiatric interviews conducted with 42 in-patients with chronic schizophrenia using two bandwidths (narrow, 128 kilobits/s; broad, 2 megabits/s) were assessed in terms of agreement with face-to-face interviews in a test-retest fashion. As a control, agreement was assessed between face-to-face interviews. Psychiatric symptoms were rated using the Oxford version of the Brief Psychiatric Rating Scale (BPRS), and agreement between interviews was estimated as the intraclass correlation coefficient (ICC).

RESULTS

The ICC was significantly lower in the narrow bandwidth than in the broad bandwidth and the control for both positive symptoms score and total score.

CONCLUSION

While reliability of televideo psychiatric interviews is insufficient using the present narrow-band internet infrastructure, the next generation of infrastructure (broad-band) may permit reliable diagnostic interviews.

Herpes simplex virus in the vestibular ganglion and the geniculate ganglion-role of loose myelin

This study presents the first direct evidence for herpes simplex virus type 1 (HSV-1) infection in the neurons of the vestibular ganglion. Although many investigators have reported electron microscopic evidence of HSV-1 infection in sensory ganglia, HSV-1 infection in the vestibular ganglion has not been described. Vestibular ganglion neurons have a unique structure, with a loose myelin sheath instead of the satellite cell sheath that is seen in other ganglia. This loose myelin is slightly different from compact myelin which is known as too tight for HSV-1 to penetrate. The role of loose myelin in terms of HSV-1 infection is completely unknown. Therefore, in an attempt to evaluate the role of loose myelin in HSV-1 infection, we looked for HSV-1 particles, or any effects mediated by HSV-1, in the vestibular ganglion as compared with the geniculate ganglion. At the light microscopic level, some neurons with vacuolar changes were observed, mainly in the distal portion of the vestibular ganglion where the communicating branch from the geniculate ganglion enters. At the electron microscopic level, vacuoles, dilated rough endoplasmic reticulum and Golgi vesicles occupied by virus were observed in both ganglia neurons. In contrast, viral infections in Schwann and satellite cells were observed only in the geniculate ganglion, but not in the vestibular ganglion. These results suggest that loose myelin is an important barrier to HSV-1 infection, and it must play an important role in the prevention of viral spread from infected neurons to other cells.

Mouse model of Bell's palsy induced by reactivation of herpes simplex virus type 1

In order to investigate the mechanism of Bell's palsy, we developed an animal model of facial nerve paralysis induced by the reactivation of herpes simplex virus type 1 (HSV-1). Eight weeks after recovery from facial nerve paralysis caused by inoculation with HSV-1, the mice were treated with auricular skin scratch at the site of the previous inoculation, or with intraperitoneal injection of anti-CD3 monoclonal antibody (mAb), or combination of both procedures. No mice developed facial nerve paralysis when they were treated with either auricular scratch or mAb injection alone. In contrast, 20% of mice developed facial nerve paralysis with the combined treatment. With one exception, no mouse treated with either auricular scratch or mAb injection showed HSV-I DNA in their facial nerve tissue, whereas 4 out of 6 mice receiving both treatments showed HSV-1 DNA on day 10 after treatment. Histopathological findings showed neuronal degeneration in the geniculate ganglion and demyelination of the facial motor nerve in paralyzed mice. These findings suggest that a combination of stimuli, local skin irritation, and general immunosuppression is essential for successfully inducing facial nerve paralysis in mice with latent HSV-1 infection.

Vibrational study on structural transitions of potassium pelargonate CH3(CH2)7CO2K

Anhydrous potassium pelargonate (KC9) undergoes four thermal transitions from room temperature to 450 degrees C. A normal mode analysis was made for the molecule in phase I at room temperature and the molecule was considered to have an all-trains conformation. With increasing temperature, partial melting of the alkyl chains occurred in phase II and complete melting was observed in phase III, as confirmed by vibrational spectra. In addition, orientational disorder of the carboxylate groups was suggested in phase II. This transition behavior of potassium pelargonate was compared with the behavior of nonane and pelargonic acid.

Gastric scirrhous carcinoma as a rare cause of aggressive fibromatosis in the neck

Aggressive fibromatosis is characterized by locally aggressive proliferation of fibroblasts and occasionally occurs in the head and neck. Although the etiology of this disease is still controversial, recent studies have shown that high levels of growth factors are found in these lesions. This article reports a case of 51-year-old woman with aggressive fibromatosis in the neck and inguinal region bilaterally. Gastric fiberscopic examination revealed a complication of advanced gastric scirrhous carcinoma. There were remarkably high levels of basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) in the serum. Postmortem autopsy examination was performed and scattered gastric carcinoma cells were observed in the fibromatosis lesions. Immunohistological staining showed positive expression of bFGF in the fibromatoses and stomach. We concluded that this was a rare case in which bFGF and PDGF released from gastric carcinoma cells caused aggressive fibromatosis by promoting unregulated proliferation of fibroblasts and collagen production locally.

[Regulation of the microtubule-dependent process formation. A review based on a comparison between the neuron and the renal glomerular podocyte]

Microtubular cytoskeletons play a crucial role in the morphogenesis of process-bearing cells, such as the neuron and the renal glomerular podocyte. Microtubules are bundled and stabilized by various microtubule-associated proteins, providing a mechanical basis to maintain the deviated morphology of cell processes. To support the process morphology, microtubules are also associated with other cytoskeletal elements such as actin and intermediate filaments. The microtubular polarity is uniformly plus-end-distal in neuronal axons, whereas in dendrites as well as in podocytes, the polarity is revealed to be non-uniform (i.e., both plus-end-distal and minus-end-distal microtubules are present in cell processes). Recently, this non-uniformity is reported to be established by a microtubule-dependent motor protein. Motor proteins are capable to drive the intracellular transport of cytoskeletal elements in addition to that of membrane vesicles. It is still an open question whether cytoskeletal elements are transported along cell processes as subunits or as polymers.

Effects of basic fibroblast growth factor (bFGF)-neutralizing antibody and platelet factor 4 on facial nerve regeneration

Exogenous basic fibroblast growth factor (bFGF) has been shown to prevent death of injured cholinergic neurons and stimulate neurite outgrowth from the proximal stump of the transected sciatic nerve. The present study was designed to examine the role of endogenous bFGF, rather than exogenous bFGF in the regenerative process of the transected facial nerve of guinea pig, by using the so-called silicone tubulization model which enabled us to bridge the transected facial nerve with a silicone tube and to inject into the tube bFGF-neutralizing antibody, normal IgG, saline, or platelet factor 4 (an antagonist for bFGF receptor). Under light microscopy, treatment with bFGF-neutralizing antibody caused significant decreases in vascular number, vascular area, and regenerating axons in the middle point of regeneration chambers at the third week after facial nerve transection, even though electron microscopy revealed that the bFGF-neutralizing antibody increased the number of thin axons with caliber smaller than 1 micrometer. Treatment with platelet factor 4 exhibited similar but more conspicuous effects on facial nerve regeneration. These findings suggest that endogenous bFGF not only facilitates angiogenesis within the transected facial nerve but also acts as a neurotrophic agent during facial nerve regeneration; it appears that endogenous bFGF contributes to the enlargement of axon caliber and increases the number of relatively large caliber axons.

[Morphological transformation of sensory ganglion neurons and satellite cells]

Sensory ganglion neurons in higher vertebrates are unique in that they are pseudounipolar with a single stem process that divides at some distance from the cell body into central and peripheral processes. In the early stages of development, these neurons are bipolar but later they became pseudounipolar. This developmental process of sensory ganglion neurons with satellite cells was examined by scanning electron microscopy following removal of connective tissue. This pseudo-unipolarization began earlier but proceeded at a slower rate in chick than in rat embryos. This difference may due to the difference found in the extent and intimacy of satellite cell investments in these two animals, which was due to the fact that sensory neurons undergo pseudo-unipolarization only in the presence of satellite cells in vitro. The neuronal perikaryal projections were observed by scanning electron microscopy after removal of connective tissue and satellite cells. Morphometric analysis reveal that perikaryal projections were more numerous on the surface of mature pseudounipolar neurons than on the surface of premature bipolar neurons, and that the number of projections increased as the neuronal cell bodies grew larger. This may support the hypothesis that perikaryal projections are structural devices for increasing the neuron-satellite interface and for improving the efficiency of metabolic exchange between these two cell types. These results suggest that satellite cells play an important role in neuronal maturation.

Tophaceous pseudogout of the temporomandibular joint: report of a case

An 85-year-old man was found to have a calcified mass protruding from the joint space of the right temporomandibular joint (TMJ). Microscopically, the removed mass consisted of chondromyxoid tissue with atypical chondrocytes, resembling a cartilaginous tumor. However, the chondromyxoid tissue contained abundant deposits of rod-shaped to rhomboid crystals which proved to be calcium pyrophosphate dihydrate (CPPD) crystals. The review of the literature revealed that tophaceous pseudogout was the most common variant of CPPD deposition disease involving the TMJ.