How deep is the inflammation in chronic rhinosinusitis? Sinus wall thickness and blood eosinophilia

Various factors have been proposed to be related to refractory chronic rhinosinusitis (CRS). Treatment for refractory CRS is challenging for ear, nose, and throat (ENT) surgeons. The aim of the study was to determine the clinical features associated with the severity of CRS that may necessitate revision surgery by eliminating the bias of the surgeons technique using standardizing surgical procedures. Sinus wall thickness and blood eosinophilia, which may represent the depth of inflammation in CRS, are associated with the need for revision surgery. We found that, when the thickness of the postero-lateral maxillary sinus wall is more than 3.03 mm, there is an increased probability for a need for revision surgery. CRS patients with thickened sinus walls were found to have poorer outcomes. Further research is needed in order to justify this type of surgical procedure for CRS.

Clinical and genetic analysis of Taiwanese patients with hereditary spastic paraplegia type 5

BACKGROUND AND PURPOSE

Spastic paraplegia type 5 (SPG5) is an autosomal recessive (AR) hereditary spastic paraplegia (HSP) associated with pure or complicated phenotypes. This study aimed to screen SPG5 in Taiwanese HSP patients.

METHODS

Sequencing of the SPG5 gene, CYP7B1, was performed in a cohort of 25 ethnic Han Taiwanese patients with AR or sporadic HSP. Clinical information and magnetic resonance imaging (MRI) were analyzed in confirmed SPG5 patients.

RESULTS

One (33%) AR kindred and four (18%) sporadic cases had CYP7B1 mutations. All of the SPG5 cases carried the mutation c.334 C>T (R112X). Haplotype analysis suggested a 'founder effect' in ethnic Hans for this mutation. The phenotype was either pure or complicated by cerebellar ataxia. For the primary HSP phenotype, there were profound dorsal column sensory deficits in all patients. Spine MRI showed thoraco-lumbar cord atrophy in some patients.

CONCLUSIONS

Spastic paraplegia type 5 is a common cause of AR and sporadic HSPs that has a higher frequency in Taiwanese than in other ethnic groups. It is associated with a CYP7B1 founder mutation and its phenotype is characterized by pronounced dorsal column sensory loss, with cerebellar ataxia in some patients.

(G2019S) LRRK2 activates MKK4-JNK pathway and causes degeneration of SN dopaminergic neurons in a transgenic mouse model of PD

(G2019S) mutation of leucine-rich repeat kinase 2 (LRRK2) is the most common genetic cause of both familial and sporadic Parkinson's disease (PD) cases. Twelve- to sixteen-month-old (G2019S) LRRK2 transgenic mice prepared by us displayed progressive degeneration of substantia nigra pars compacta (SNpc) dopaminergic neurons and parkinsonism phenotypes of motor dysfunction. LRRK2 is a member of mixed lineage kinase subfamily of mitogen-activated protein kinase kinase kinases (MAPKKKs). We hypothesized that (G2019S) mutation augmented LRRK2 kinase activity, leading to overphosphorylation of downstream MAPK kinase (MKK) and resulting in activation of neuronal death signal pathway. Consistent with our hypothesis, (G2019S) LRRK2 expressed in HEK 293 cells exhibited an augmented kinase activity of phosphorylating MAPK kinase 4 (MKK4) at Ser(257), and protein expression of active phospho-MKK4(Ser257) was upregulated in the SN of (G2019S) LRRK2 transgenic mice. Protein level of active phospho-JNK(Thr183/Tyr185) and phospho-c-Jun(Ser63), downstream targets of phospho-MKK4(Ser257), was increased in the SN of (G2019S) LRRK2 mice. Upregulated mRNA expression of pro-apoptotic Bim and FasL, target genes of phospho-c-Jun(Ser63), and formation of active caspase-9, caspase-8 and caspase-3 were also observed in the SN of (G2019S) LRRK2 transgenic mice. Our results suggest that mutant (G2019S) LRRK2 activates MKK4-JNK-c-Jun pathway in the SN and causes the resulting degeneration of SNpc dopaminergic neurons in PD transgenic mice.

Contribution of glucocerebrosidase mutation in a large cohort of sporadic Parkinson's disease in Taiwan

BACKGROUND AND PURPOSE

The association between glucocerebrosidase (GBA) mutations and Parkinson's disease (PD) is attracting increased attention worldwide. In patients of Chinese ethnicity, other than the common L444P mutation, a few mutations have been reported. However, the contribution of GBA to PD can be answered only by a thorough investigation of its mutations in a unique large population.

METHODS

We enrolled 1747 participants: 967 PD patients and 780 healthy individuals. We screened entire GBA coding regions and exon-intron boundaries in 30 randomly chosen PD patients, followed by testing five variants (L444P, D409H, R120W, L174P, and Q497R) in all participants. The G2385R and R1628P in LRRK2 had been previously studied in almost all participants.

RESULTS

  In total, 36 patients (3.72%) carried a heterozygous mutant GBA allele (27 L444P, 7 RecNciI, and 2 D409H). Only two controls (0.26%) carried heterozygous GBA mutation (1 L444P and 1 RecNciI). In PD group, the mean age at onset in carriers was younger than in non-carriers. The difference in percentage of mutation frequencies between patients and controls was highly significant for the L444P mutation (P < 0.0001). One L444P carrier was also associated with LRRK2 G2385R variant, but no atypical Parkinsonism was observed.

CONCLUSIONS

The present study ascertains that L444P mutation in GBA gene may contribute to an earlier onset of development of PD in Han/Chinese population. Following LRRK2 variants, GBA is the second most frequent mutations indicated for sporadic PD development in the Han/Chinese population. These GBA carriers are associated with an earlier onset of Parkinsonism.

Nocistatin excites rostral agranular insular cortex-periaqueductal gray projection neurons by enhancing transient receptor potential cation conductance via G(alphaq/11)-PLC-protein kinase C pathway

Rostral agranular insular cortex (RAIC) projects to periaqueductal gray (PAG) and inhibits spinal nociceptive transmission by activating PAG-rostral ventromedial medulla (RVM) descending antinociceptive circuitry. Despite being generated from the same precursor prepronociceptin, nocistatin (NST) and nociceptin/orphanin FQ (N/OFQ) produce supraspinal analgesic and hyperalgesic effects, respectively. Prepronociceptin is highly expressed in the RAIC. In the present study, we hypothesized that NST and N/OFQ modulate spinal pain transmission by regulating the activity of RAIC neurons projecting to ventrolateral PAG (RAIC-PAG). This hypothesis was tested by investigating electrophysiological effects of N/OFQ and NST on RAIC-PAG projection neurons in brain slice. Retrogradely labeled RAIC-PAG projection neurons are layer V pyramidal cells and express mRNA of vesicular glutamate transporter subtype 1, a marker for glutamatergic neurons. N/OFQ hyperpolarized 25% of RAIC-PAG pyramidal neurons by enhancing inwardly rectifying potassium conductance via pertussis toxin-sensitive G(alphai/o). In contrast, NST depolarized 33% of RAIC-PAG glutamatergic neurons by causing the opening of canonical transient receptor potential (TRPC) cation channels through G(alphaq/11)-phospholipase C-protein kinase C pathway. There were two separate populations of RAIC-PAG pyramidal neurons, one responding to NST and the other one to N/OFQ. Our results suggest that G(alphaq/11)-coupled NST receptor mediates NST excitation of RAIC-PAG glutamatergic neurons, which is expected to cause the supraspinal analgesia by enhancing the activity of RAIC-PAG-RVM antinociceptive pathway. Opposite effects of NST and N/OFQ on supraspinal pain regulation are likely to result from their opposing effects on RAIC-PAG pyramidal neurons.

Novel mutations at carboxyl terminus of CIC-1 channel in myotonia congenita

OBJECTIVES

Myotonia congenita (MC), caused by mutations in the muscle chloride channel (CLCN1) gene, can be inherited dominantly or recessively. The mutations at the carboxyl terminus of the CLCN1 gene have been identified in MC patients, but the functional implication of these mutations is unknown.

MATERIAL AND METHODS

Direct sequencing of polymerase chain reaction products covering the whole coding region of the CLCN1 gene was performed in a MC family. This study was designed to investigate the clinical manifestations and genetic analysis of the CLCN1 gene.

RESULTS

We identified two novel mutations, 2330delG and 1892C>T, from a genetic screening of the CLCN1 gene in the MC family. The 2330delG mutant allele producing a fs793X truncated protein was identified in a heterozygous state in all the patients. The 1892C>T nucleotide change induced a missense mutation (T631I) found in several asymptomatic individuals, indicating that it may not be associated with MC. Intriguingly, the 2330delG mutation was also found in an asymptomatic subject who also carried the 1892C>T mutation.

CONCLUSION

The data indicate that the fs793X mutant protein causes dominantly inherited MC. Because the mutation has been found in a recessive pedigree, the fs793X mutation may have a dual inheritance pattern.

Na+,K+-ATPase and Ca2+-ATPase activities in the cochlear lateral wall following surgical induction of hydrops

Na+,K+-ATPase and Ca2+-ATPase activities have not been studied quantitatively in the cochlea affected by endolymphatic hydrops. The present study was designed to measure quantitatively the Na+,K+-ATPase and Ca2+-ATPase activities in the cochlear lateral wall and the threshold of auditory brainstem response (ABR) for guinea pigs in the early stages (=2 months) of experimentally induced endolymphatic hydrops. A significant negative association was demonstrated between Ca2+-ATPase activity and the change in ABR threshold for hydropic cochleae (P=0.014), but not for control cochleae (P=0.123), although no such significant association was revealed between Na+,K+-ATPase activity and any change in ABR threshold for both hydropic cochleae (P=0.751) and control cochleae (P=0.352). A significant increase in Ca2+-ATPase activity in the cochlear lateral wall was observed for the hydropic ear, in which normal ABR thresholds were maintained, as compared to the control ear. On the contrary, a mild decrease in Ca2+-ATPase activity in the cochlear lateral wall was observed for the hydropic ear, in which ABR thresholds increased significantly. The present findings suggest that alterations of Ca2+-ATPase activity in the cochlear lateral wall may implicate disturbed calcium-homeostasis in the inner ear, resulting in hearing dysfunction in the early stages of experimentally induced endolymphatic hydrops.

Neurotensin excitation of serotonergic neurons in the rat nucleus raphe magnus: ionic and molecular mechanisms

To understand the cellular and molecular mechanisms by which neurotensin (NT) induces an analgesic effect in the nucleus raphe magnus (NRM), whole-cell patch-clamp recordings were performed to investigate the electrophysiological effects of NT on acutely dissociated NRM neurons. Two subtypes of neurons, primary serotonergic and secondary non-serotonergic cells, were identified from acutely isolated NRM neurons. During current-clamp recordings, NT depolarized NRM serotonergic neurons and evoked action potentials. Voltage-clamp recordings showed that NT excited serotonergic neurons by enhancing a voltage-insensitive and non-selective cationic conductance. Both SR48692, a selective antagonist of subtype 1 neurotensin receptor (NTR-1), and SR 142948A, a non-selective antagonist of NTR-1 and subtype 2 neurotensin receptor (NTR-2), failed to prevent neurotensin from exciting NRM serotonergic neurons. NT-evoked cationic current was inhibited by the intracellular administration of GDP-beta-S. NT failed to induce cationic currents after dialyzing serotonergic neurons with the anti-G(alphaq/11) antibody. Cellular Ca(2+) imaging study using fura-2 showed that NT induced the calcium release from the intracellular store. NT-evoked current was blocked after the internal perfusion of heparin, an IP(3) receptor antagonist, or BAPTA, a fast Ca(2+) chelator. It is concluded that neurotensin enhancement of the cationic conductance of NRM serotonergic neurons is mediated by a novel subtype of neurotensin receptors. The coupling mechanism via G(alphaq/11) proteins is likely to involve the generation of IP(3), and subsequent IP(3)-evoked Ca(2+) release from intracellular stores results in activating the non-selective cationic conductance.

Mucociliary transport pathway on laryngotracheal tract and stented glottis in guinea pigs

We investigated the laryngotracheal mucociliary transport pathway of guinea pigs in vivo and immediately postmortem. Only intraperitoneal anesthesia was used during the procedure to avoid the disturbance of mucociliary function. Resin particles were used as the marking substance. A microcolpohysteroscope was placed at different levels in the laryngotracheal region for observing the marking particles and recording the transport pattern. The tracheal mucociliary transport flow primarily moved along the posterior wall and both lateral walls in a zigzag trace. Upon reaching the subglottis, the resin particles stayed underneath the vocal cords, and a whirlpool phenomenon developed. The majority of the particles were shifted and directed onto the posterior glottic area. With a short delay, some resin particles crossed over the free edge of the vocal cords and turned posteriorly along the medial upper cordal margin. No mucociliary transport could be observed on the entire upper surface of the true vocal cords, which is covered by squamous epithelium. Occasionally, a few resin particles in the vicinity of the epiglottic root traveled along the aryepiglottic folds toward the posterior commissure. All streams of mucociliary transport finally joined together in the interarytenoid area. After leaving the glottis, the resin particles traveled to the hypopharynx and entered the esophagus through the motion of deglutition. The pattern of mucociliary clearance in the laryngotracheal region was not delayed by stenting.

A cationic nonselective stretch-activated channel in the Reissner's membrane of the guinea pig cochlea

The Reissner's membrane (RM) separates in the mammalian cochlea the K(+)-rich endolymph from the Na(+)-rich perilymph. The patch-clamp technique was used to investigate the transport mechanisms in epithelial cells of RM freshly dissected from the guinea pig cochlea. This study shows a stretch-activated nonselective cationic channel (SA channel) with a linear current-voltage relationship (23 pS) highly selective for cations over anions [K+ approximately Na+ (1) > Ba2+ (0.65) > Ca2+ (0.32) >> Cl- (0.14)] and activated by the intrapipette gradient pressure. The open probability-pressure relationship is best fitted by a Boltzmann distribution (half-maximal pressure = 37.8 mmHg, slope constant = 8.2 mmHg). SA channels exhibit a strong voltage dependency and are insensitive to internal Ca2+, ATP, and fenamates but are blocked by 1 microM GdCl3 in the pipette. They are reversibly activated by in situ superfusion of the cell with hyposmotic solutions. Kinetic studies show that depolarization and mechanical or osmotic stretch modify the closed and open time constants probably by a different mechanism. These channels could participate in pressure-induced modifications of ionic permeability of the RM.

Vasoactive intestinal peptide stimulation of human trabecular meshwork cell growth

PURPOSE

To demonstrate that vasoactive intestinal peptide (VIP), a 28-amino acid neuropeptide, is a growth factor of human trabecular meshwork (TM) cells in culture and in a corneoscleral explant organ culture treated with laser trabeculoplasty (LTP).

METHODS

Proliferating human TM cells in cell cultures were incubated with VIP for 20 hours, followed by total cell number determination, using a Coulter counter. The percentage of proliferating TM cells was assessed, using an antibody against the proliferating cell nuclear antigen (PCNA). To test the growth effect of VIP on TM cells in situ, corneoscleral explants in organ cultures were first treated with argon LTP to initiate TM-cell proliferation and then were exposed to VIP for 48 hours. The mitotic TM cells were demonstrated immunocytochemically, using anti-PCNA in paraffin sections of the explants; and the total number of TM cells was determined after paraffin sections were counterstained by hematoxylin.

RESULTS

Vasoactive intestinal peptide dose-dependently stimulated the proliferation of TM cells in cell culture. Treatment with 5 x 10(-10) M VIP resulted in a maximal increase of 40% in cell number. The effect of VIP was blocked by a VIP antagonist. The number of PCNA-stained TM cells and the total cell number in the TM in LTP-treated corneoscleral explants were increased by VIP.

CONCLUSIONS

Exogenously applied VIP stimulated the proliferation of human TM cells in subconfluent cultures and in LTP-treated corneoscleral explants. In that LTP has been shown to increase the number of TM cells in situ, the growth stimulatory effect of VIP may help enhance this therapy.

Stretch-activated nonselective cation, Cl- and K+ channels in apical membrane of epithelial cells of Reissner's membrane

Ion channels on the apical membrane of epithelial cells (the surface facing the endolymph) of acutely isolated Reissner's membrane from guinea-pig cochlea were investigated by using patch-clamp technique in cell-attached and inside-out configurations. Three types of ion channel were identified: namely, a stretch-activated nonselective cation, a chloride and a potassium channel. When the pipette was filled with high-K+ endolymph-like solution, the most significant channel activity was nonselective cation channels (85/110, 77% patches). The current versus voltage relationship was linear with a unitary conductance of 22.1 +/- 0.4 pS and reversal potential (Vr) of 2.3 +/- 0.8 mV (n = 18). The channel exhibited a lower conductance (14.0 +/- 0.6 pS, n = 8) to Ca2+. The open probability was low (NPo approximately 0.1) in cell-attached configuration under +60 mV pipette potential and increased when the membrane was stretched with negative pressure. The channel was blocked by 10 microM extracellular Gd3+. The two other types of channels were a small voltage-sensitive Cl- channel (6.0 +/- 0.3 pS; 91/99, 92% patches) and a K+ channel (approximately 30 pS; 29/191, 15% patches). These channels might play roles in the regulation of cell volume, in balancing the hydrostatic pressure across Reissner's membrane and in maintaining the electrochemical composition of endolymph.

Characterization of Ca(2+)- and voltage-dependent nonselective cation channels in human HepG2 cells

Nonselective cation channels have been identified and linked to important cell functions in rat hepatocytes. In this study, we characterized inward rectifying nonselective cation channels in detail by the patch clamp technique in human HepG2 cells. Channel properties were studied with high resistance borosilicate pipettes in cell-attached and inside-out configurations. With Ringer's solution and KCl as pipette solutions, the conductances were 19.7 +/- 2.1 and 22.2 +/- 0.0 picosiemens (pS), and reversal potentials were 30.9 +/- 3.5 and 31.3 +/- 4.6 mV, respectively. The channel was permeable to Ba2+, and the sequence of permeability ratios was Na+ > K+ > Cs+ > Ba2+. In the cell-attached configuration, the channel had a higher opening probability at depolarizing potential than at hyperpolarizing. In the inside-out patches with symmetric Ringer's solution, the current voltage curve was linear with conductance of 19.8 +/- 0.9 pS. Reversal potential shifted from -0.2 +/- 1.0 mV to 23.2 +/- 1.0 mV when the bath solution was replaced by dilute Ringer's solution. In the inside-out configuration, the gating was Ca(2+)-dependent, and the opening probability increased with increasing intracellular calcium concentration ([Ca2+]i). An outward rectifying channel appeared when [Ca2+]i was less than 1 mumol/L. The nonselective channel was reversibly blocked by 10 mumol/L internal flufenamic acid. We conclude that Ca(2+)- and voltage-dependent nonselective cation channels are present in human HepG2 cells. The channels might be involved in the regulation of Ca2+ influx and are associated with activation of other ion channels.

Mixed meningococcal and tuberculous meningitis

Meningococcal meningitis is one of the most common bacterial infections of the meninges worldwide, and tuberculous infection is the most common cause of chronic meningitis in Taiwan. However, mixed meningococcal and tuberculous meningitis is rare. We describe a 27-year-old woman with a case of culture-proven meningococcal and tuberculous meningitis verified by polymerase chain reaction on a cerebrospinal fluid specimen. The patient was initially treated with intravenous antibiotics including penicillin G and chloramphenicol. Though the patient responded well to therapy initially, her subsequent clinical deterioration was finally controlled by long-term antituberculous medications.

Mucociliary clearance of stented laryngotracheal tract in guinea pigs in vivo

The purpose of this study was to investigate laryngotracheal mucociliary transport by means of an in vivo guinea pig model with and without a stent. The experimental design involved marking with deep-colored resin powder and utilizing the serial photograph-analyzing method via endoscopic laryngeal videography. Fifteen animals were grouped into two airway conditions: 5 with laryngotracheal stent insertion and 10 without. The mucociliary transit time and mucociliary transport rate were measured in both groups. Significant differences between the two groups were found. In conclusion, stenting preserved and increased the clearance function of the laryngotracheal mucosa in the acute phase.

Characterization and relative abundance of maxi-chloride channels in Epstein-Barr virus (EBV) producer: B95-8 cells

Several Epstein-Barr virus (EBV)-transformed cell lines were used to investigate the pathogenesis of lymphoproliferative diseases and nasopharyngeal carcinoma. The studies focus on the events occurring inside the membrane. On only one occasion, the cell membrane of EBV-transformed B lymphocytes from a cystic fibrosis patient was found to express defective Cl channels (CFTR; Cystic Fibrosis Transmembrane conductance Regulator), as in the airway epithelial cell. No other type of channel in EBV-transformed cells has so far been investigated. In this study, the cell membrane of the B95-8 cell was examined by the patch-clamp technique and compared to the non-EBV-infected BJAB cell. The high conductance (approximately 300 pS) maxi-chloride (Cl) channel activity was the most frequently observed event in inside-out configurations. Under similar experimental conditions, we have found a significantly higher probability of detecting maxi-Cl channel activity on the cell membrane of B95-8 cells (69%) than on BJAB cells (27%), or as previously reported on resting murine B lymphocytes (38%) or intact human T lymphocytes (37%). The relative abundance of the maxi-Cl channel on B95-8 cells may be linked to EBV infection and/or secretory ability.

Steroid hormone receptors in three human gastric cancer cell lines

Steroid hormone receptors in three human gastric adenocarcinoma cell lines and their transplanted tumors (except nontumorigenic KATO-III) in nude mice were determined by dextran-coated charcoal assay. Progesterone receptors (PgR) were found in all cell lines, transplanted NUGC-3, and AZ 521 tumors. Estrogen receptors (ER) were found in KATO-III cells, transplanted NUGC-3, and AZ 521 tumors, whereas glucocorticoid receptors (GR) were found only in NUGC-3 tumor and no androgen receptor was found in any cell lines or transplanted tumors. Since NUGC-3 cells had ER, PgR, and GR, it was used for the study of the effects of steroid hormones on growth. The results showed the cell cycle phase distributions and growth rate of transplanted tumors were similar in hormone-treated and nontreated groups. The persistent expression of PgR in gastric cancer cell lines and tumors, and the slight increase of tumor volumes in the progesterone-treated group suggests that progesterone and its receptors may be important in the pathogenesis of gastric cancer, but their biological function remains to be elucidated.

Primary culture of Reissner's membrane from the gerbil: growth, morphologic features, and characterization

To overcome the technical difficulties encountered in investigating the physiology of Reissner's membrane (RM), primary culture of RM was established. Minute explants obtained by mechanical dissociation were seeded on impermeable substrate coated with collagen type I in serum-free, hormone-supplemented medium. Within 2 weeks, a large cultured area was obtained which reproduced the two cell layers of the original explant. One layer, deep or superficial depending on the side to which the explant adhered, was made of cells exhibiting light and electron microscopy characteristics of an epithelium. Immunohistochemical methods revealed that they expressed cytokeratin, demonstrating their epithelial nature. The second layer was made of mesenchymal cells. This study suggests that cell culture of RM will facilitate further investigation of its physiology.

Regulation of arginase production by glucocorticoid in three human gastric cancer cell lines

Gastric cancer tissues have high levels of glucocorticoid receptors (GR) and arginase. To investigate the interrelation of glucocorticoid, GR and arginase, three human gastric cancer cell lines (AZ-521, NUGC-3, KATO-III) were treated with hydrocortisone in the presence or absence of a glucocorticoid antagonist RU38486. GR were found to be present in all three lines, and hydrocortisone significantly increased the production of total arginase in all 3 lines. The induction of arginase production by hydrocortisone was inhibited by RU38486. These findings suggest that the regulation of arginase production by hydrocortisone in gastric cancer cells is mediated through GR.

Contribution of cell culture to the study of the physiology of the stria vascularis and Reissner's membrane

Cell culture is a well-established tool in cell biology which may overcome the limitations of the experimental methods currently used to investigate the physiology of labyrinthine fluids. Using explant and dissociated cell culture technique, sheets of oriented cells derived from the stria vascularis and Reissner's membrane may be obtained, which allows new experimental approaches such as the patch-clamp technique. Other experimental approaches are considered which might improve our understanding of inner ear physiology.