Receptors of glutamate and neurotrophin in vestibular neuronal functions

The last decade has witnessed advances in understanding the roles of receptors of neurotrophin and glutamate in the vestibular system. In the first section of this review, the biological actions of neurotrophins and their receptors in the peripheral and central vestibular systems are summarized. Emphasis will be placed on the roles of neurotrophins in developmental plasticity and in the maintenance of vestibular function in the adult animal. This is reviewed in relation to the developmental expression pattern of neurotrophins and their receptors within the vestibular nuclei. The second part is focused on the functional role of different glutamate receptors on central vestibular neurons. The developmental expression pattern of glutamate receptor subunits within the vestibular nuclei is reviewed in relation to the potential role of glutamate receptors in regulating the development of vestibular function.

Complete synchronization and generalized synchronization of one-way coupled time-delay systems

The complete synchronization and generalized synchronization (GS) of one-way coupled time-delay systems are studied. We find that GS can be achieved by a single scalar signal, and its synchronization threshold for different delay times shows the parameter resonance effect, i.e., we can obtain stable synchronization at a smaller coupling if the delay time of the driven system is chosen such that it is in resonance with the driving system. Near chaos synchronization, the desynchronization dynamics displays periodic bursts with the period equal to the delay time of the driven system. These features can be easily applied to the recovery of time-delay systems.

Carpal tunnel syndrome due to gouty infiltration of the lumbrical muscles and flexor tendons

A case of gout first presenting as carpal tunnel syndrome due to intratendinous and lumbrical muscle involvement with tophi is reported. Surgical decompression with excision of tophi and diseased muscle produced symptomatic relief.

Measure synchronization in coupled phi4 Hamiltonian systems

Transitions to measure synchronization both in the quasiperiodic and chaotic cases are investigated based on numerical computation of two coupled phi(4) equations. Some relevant quantities such as the bare energies, the interaction energy, and the phase difference of the two oscillators are computed to clarify the characteristics of the transitions and the measure-synchronous states. A bifurcation with discontinuous bare energy and continuous interaction energy, which takes the maximum value at the critical point, is found for the transition from the desynchronous quasiperiodic state to the measure-synchronous quasiperiodic state, and the related power law scalings are deduced. Stick-slip and random-walk-like behavior of the phase difference is found for the chaotic measure-synchronous state, and this explains the monotonous increase of the interaction energy with an increase of coupling.

Neurotrophin receptor immunostaining in the vestibular nuclei of rats

The distribution of high-affinity neurotrophin receptors in cells of the vestibular nuclear complex and its subnuclei of adult rats was examined. We noted a high density of tyrosine kinase (Trk) A- and B- and a lower density of TrkC-immunostained cells. In particular, long, intensely labelled immunostained-TrkB fibres formed networks in the neuropil. Both TrkA- and TrkB-immunostained cells were widely distributed in the lateral, medial and spinal vestibular nuclei, and were less frequently seen in the superior vestibular nucleus, x and y subnuclei. However, immunostaining for TrkC was weak in many cells within the vestibular nuclei. The widespread and abundant neuronal distribution of Trk receptors predicts that their associated neurotrophins exert significant effects on individual cells within the vestibular nuclei.

Response properties of Y group neurons to crossed otolith inputs in the cat

The response properties of extracellularly recorded Y group neurons on the lesioned side were examined in decerebrate cats after acute hemilabyrinthectomy, with the use of constant velocity off-vertical axis rotations (OVAR) to stimulate the remaining intact otolith receptors. During rotation in the clockwise or counterclockwise direction, Y group neurons displayed a spectrum of position-dependent bidirectional response sensitivities, ranging from one- to two-dimensional. Some two-dimensional neurons even exhibited unidirectional responses with change in OVAR velocity. These findings indicate that Y group neurons have the capacity to code spatiotemporal signals arising from the contralateral otolith. The best response orientations of one-dimensional and two-dimensional neurons were found predominantly along the antero-posterior direction, thus providing a spatial framework for the otolithic reflexes.

Prognostic value of age and histologic type in neoadjuvant chemotherapy plus radical surgery for bulky (>/=4 cm) stage IB and IIA cervical carcinoma

The purpose of this study was to investigate pretreatment variables related to prognosis and to evaluate long-term outcome in patients with bulky early-stage cervical carcinoma who were enrolled into a protocol treatment of neoadjuvant chemotherapy (NAC) followed by radical surgery. Between 1988 and 1999, 162 women with previously untreated bulky (>/=4 cm) stage IB or IIA carcinoma of the uterine cervix registered to receive cisplatin, vincristine, and bleomycin for three cycles followed by radical hysterectomy and pelvic lymphadenectomy, were enrolled into this study. The 5-year relapse-free (RFS) and overall survival (OS) rates of the whole series were 65% and 69%, respectively. In multivariate analyses, age (< 35 vs. >/= 35-year-old: relative risk [RR], 2.06; 95% confidence interval [CI], 1.02-4.14; P = 0.043) and histologic type (adeno-adenosquamous vs. squamous carcinoma: RR, 2.60; 95% CI, 1.26-5.39; P = 0.010) were independent variables associated with RFS, and age (< 35 vs. >/= 35-year-old: RR, 2.53; 95% CI, 1.24-5.14; P = 0.010) and pre-NAC tumor size (> 5 vs. = 5 cm: RR, 2.06; 95% CI, 1.09-3.90; P = 0.027) were significantly related to OS. Narrowing down patient selection to squamous carcinoma and age older than 35 years with stratification of tumor size (break point of 5 cm) is recommended in future trials involving cisplatin-based NAC plus radical surgery.

Source profiles and ozone formation potentials of volatile organic compounds in three traffic tunnels in Kaohsiung, Taiwan

Twenty-five volatile organic compounds (VOCs) up to C10 were measured using Carbotrap multibed thermal adsorption tubes during the morning and afternoon rush hours on four different days in all three traffic tunnels in Kaohsiung, Taiwan. A gas chromatograph (GC) equipped with a flame-ionization detector (FID) was then used to analyze the VOCs. The analytical results show that VOC concentrations increase with traffic flow rate, and emission profiles in the three tunnels are mostly in the range C2-C6. In addition to the traffic conditions and vehicle type, the pattern of emissions in each tunnel was also influenced by other factors, such as vehicle age, nearby pollution sources, and the spatial or temporal variation of VOCs in the urban atmosphere. The ozone formation potential (OFP) in each tunnel was assessed based on the maximum incremental reactivities of the organic species, demonstrating that OFP increases with traffic flow rate. Vehicle distribution influences the contributions of organic group to OFP in a tunnel. Meanwhile, when ranked in descending order of contribution to OFP in all tunnels, the organic groups followed the sequence olefins, aromatics, and paraffins.

Tailoring wavelets for chaos control

Chaos is a class of ubiquitous phenomena and controlling chaos is of great interest and importance. In this Letter, we introduce wavelet controlled dynamics as a new paradigm of dynamical control. We find that by modifying a tiny fraction of the wavelet subspaces of a coupling matrix, we could dramatically enhance the transverse stability of the synchronous manifold of a chaotic system. Wavelet controlled Hopf bifurcation from chaos is observed. Our approach provides a robust strategy for controlling chaos and other dynamical systems in nature.

Bilateral otolith contribution to spatial coding in the vestibular system

Recent work on the coding of spatial information in central otolith neurons has significantly advanced our knowledge of signal transformation from head-fixed otolith coordinates to space-centered coordinates during motion. In this review, emphasis is placed on the neural mechanisms by which signals generated at the bilateral labyrinths are recognized as gravity-dependent spatial information and in turn as substrate for otolithic reflexes. We first focus on the spatiotemporal neuronal response patterns (i.e. one- and two-dimensional neurons) to pure otolith stimulation, as assessed by single unit recording from the vestibular nucleus in labyrinth-intact animals. These spatiotemporal features are also analyzed in association with other electrophysiological properties to evaluate their role in the central construction of a spatial frame of reference in the otolith system. Data derived from animals with elimination of inputs from one labyrinth then provide evidence that during vestibular stimulation signals arising from a single utricle are operative at the level of both the ipsilateral and contralateral vestibular nuclei. Hemilabyrinthectomy also revealed neural asymmetries in spontaneous activity, response dynamics and spatial coding behavior between neuronal subpopulations on the two sides and as a result suggested a segregation of otolith signals reaching the ipsilateral and contralateral vestibular nuclei. Recent studies have confirmed and extended previous observations that the recovery of resting activity within the vestibular nuclear complex during vestibular compensation is related to changes in both intrinsic membrane properties and capacities to respond to extracellular factors. The bilateral imbalance provides the basis for deranged spatial coding and motor deficits accompanying hemilabyrinthectomy. Taken together, these experimental findings indicate that in the normal state converging inputs from bilateral vestibular labyrinths are essential to spatiotemporal signal transformation at the central otolith neurons during low-frequency head movements.

Transition from intermittency to periodicity in lag synchronization in coupled Rössler oscillators

The dynamical and statistical behavior of lag synchronization in two coupled self-sustained chaotic Rössler oscillators is reexamined. The lack of uniqueness in the conventional characterization of lag synchronization based on the similarity function has caused much skepticism about the existence of lag synchronization. We provide an evidence that the emergence of lag synchronization is associated with the transition from on-off intermittency to a periodic structure in the laminar phase distribution.

Primary resistance to antibiotics and its clinical impact on the efficacy of Helicobacter pylori lansoprazole-based triple therapies

AIM

To evaluate Helicobacter pylori primary resistance and its clinical impact on the efficacy of two lansoprazole-based eradication triple therapies.

METHODS

H. pylori-positive patients (n=228) were randomized to receive one of the 1-week regimens: lansoprazole 30 mg, clarithromycin 500 mg and amoxicillin 1 g (LAC), or lansoprazole 30 mg, clarithromycin 500 mg and metronidazole 500 mg (LMC), each given twice daily. H. pylori status was assessed by 13C-urea breath test and culture at diagnosis and by 13C-urea breath test 6 weeks after therapy. Antibiotic susceptibility was determined by E-test (n=98).

RESULTS

The eradication rates with per protocol/ intention-to-treat analyses were: LAC (n=95/114) 83%/69% and LMC (n=96/114) 85%/72%. Primary resistance was 11% for clarithromycin, 41% for metronidazole and 0% for amoxicillin. Eradication in metronidazole-susceptible/-resistant strains was 85%/82% in LAC and 83%/63% in LMC. Significantly lower cure rates were observed in clarithromycin-resistant patients treated with LAC (95% vs. 0%, P < 0.001) and LMC (86% vs. 0%, P < 0.001).

CONCLUSIONS

One-week LAC and LMC are similarly effective therapies. Clarithromycin resistance significantly affected H. pylori eradication in both regimens.

Lens subluxation: 10-years' experience at Chang Gung Memorial Hospital, Kaohsiung

BACKGROUND

This study aimed to describe the clinical manifestations and surgical outcomes of subluxated lens.

METHODS

Reviewing charts from January 1991 to June 2000, we studied 110 patients (123 eyes) who had lens subluxation at Chang Gung Memorial Hospital, Kaohsiung. For 21 eyes, patients accepted conservative treatment, and 102 eyes underwent surgery (8 eyes had Marfan syndrome; 18 eyes had idiopathic dislocation; and 76 eyes had experienced trauma). Indications of surgery included reduction in visual acuity, uncorrectable refractive error, and secondary glaucoma.

RESULTS

There were 81 male and 29 female patients. Their mean age was 47.6 years (range, 2-76 years). The mean post-operative follow-up period was 22.24 months (range, 2-118 months). In spite of the different lens statuses, similar visual results were found between the surgical treatment group and the nonsurgery group. In the surgery group, 47 eyes (46.1%) achieved best corrected visual acuity (BCVA) of 20/40 or better. A total of 80 eyes (78.4%) achieved an improvement (log MAR change >0.3) in BCVA. The major postoperative complications included glaucoma (11 eyes), retinal detachment (9 eyes) and intraocular lens dislocation into the vitreous cavity (3 eyes).

CONCLUSIONS

Results indicate that the presence of a subluxated lens alone is not an absolute indication for surgical removal. The lens status had no significant influence on surgical outcome. Most cases can achieve an improvement in BCVA after appropriate management.

Lymphangioma circumscriptum treated with pulsed dye laser

Lymphangioma circumscriptum is a lymphatic malformation that involves the skin and may extend to subcutaneous tissue and muscle. Treatment of these lesions is challenging. Surgical excision may be performed but recurrence is common. Herein we report a child with a symptomatic lymphangioma circumscriptum that was treated with pulsed dye laser with good results. For superficial lymphatic malformations containing blood, pulsed dye laser might be considered as a treatment option.

Intralesional injection for hepatic metastasis from cervical carcinoma. A report of two cases

BACKGROUND

The treatment of isolated hepatic metastasis from carcinoma of the uterine cervix has yet to be established. We tested the efficacy of percutaneous injection of ethanol and acetic acid as a curative-intent treatment modality for this rare event.

CASES

Under real-time sonographic guidance, two patients with a solitary hepatic metastasis from carcinoma of the cervix were treated with 99.5% percutaneous ethanol injection (one patient) and 50% percutaneous acetic acid injection (the other patient). The treatment was repeated weekly if laboratory data permitted and aspiration cytology interpreted on site showed tumor cells. Cytology after complete treatment showed no residual tumor cells in either case. Both patients had no evidence of disease during follow-up for 12 and 24 months, respectively.

CONCLUSION

Treatment was successful in two patients with isolated hepatic metastatic lesions from carcinoma of the cervix who received percutaneous injection of 99.5% ethanol or 50% acetic acid.

Isolated paraaortic lymph node recurrence after definitive irradiation for cervical carcinoma

PURPOSE

To evaluate the clinical features of isolated paraaortic lymph node (PALN) recurrence after definitive radiotherapy, and analyze the prognostic factors and effect of salvage treatment.

METHODS AND MATERIALS

Of a total 876 patients who received pelvic radiotherapy after the diagnosis of primary cervical carcinoma, 26 were found to have isolated PALN recurrence as the first recurrent site, and these patients enrolled in this study. Only those with primary-site carcinoma controlled and who were free of other distant metastases were eligible. Nineteen of the 26 patients accepted salvage therapy. Fourteen patients accepted concurrent chemoradiation (CCRT), 1 accepted radiation to the paraaortic region, and 4 accepted chemotherapy alone. Clinical parameters evaluated included tumor markers (SCC and CEA) and image studies.

RESULTS

Seven of the 26 patients were alive and disease-free. All 7 survivors had salvage treatment with radiation to the paraaortic region and concurrent cisplatin-based chemotherapy. None of the patients receiving chemotherapy or radiation alone enjoyed long-term, disease-free survival. The 5-year survival rate for isolated PALN recurrence of the 14 patients who accepted salvage concurrent chemoradiation (CCRT) was 51.2%. The presence of a clinical symptom at the time of PALN recurrence was analyzed. Seven of the 12 asymptomatic patients and none of the 14 symptomatic patients survived without disease after salvage treatment. The SCC levels at recurrence showed a statistically significant relationship to disease-free survival.

CONCLUSIONS

An SCC level of < or = 4 ng/ml and a lack of symptoms at the time of recurrence were good prognostic factors in isolated PALN recurrence after primary radiation therapy. In addition to concurrent CCRT, periodical surveillance with tumor markers and imaging studies allowed early detection and salvage of those patients.

Limb preservation by Gore-Tex vascular graft for groin recurrence after postoperative adjuvant radiation in vulvar cancer

BACKGROUND

Recurrent vulvar cancer involving the femoral artery after groin radiation is usually considered inoperable. A patient with such recurrent vulvar cancer successfully treated by femoral vascular graft and rectus abdominis myocutaneous flap reconstruction with limb salvage is described.

CASE

A 51-year-old woman had recurrent vulvar cancer involving the right femoral vessels 6 months after a radical vulvectomy plus inguinal lymphadenectomy and postoperative pelvic and groin radiation. Radical en bloc excision of tumor along with the involved femoral artery and vein followed by Gore-Tex vascular graft and rectus abdominis myocutaneous flap reconstruction led to a complete remission. However, occlusion of the grafted vessels occurred 21 months following bypass surgery. Since the compensatory collaterals were established, debridement and removal of the occluded graft were carried out. The patient has been clinically free of disease for more than 48 months since graft reconstruction surgery.

CONCLUSION

It is highlighted that aggressive tumor resection with limb salvage is feasible even for patients with vulvar cancer of the groin recurrence involving the femoral artery after primary surgery and groin radiation.

Removal of metal ions and humic acid from water by iron-coated filter media

Iron oxide is an excellent, regenerable adsorbent, and often controls free metals through adsorption reaction. The utilization of heating process for coating iron oxide on sand surface allowed the media to be used in a packed column. Iron-coated sand was investigated for adsorbing metal ions and natural organic matter from water by batch and column experiments. Chemical analysis (energy dispersive analysis of X-ray, EDAX) was used for characterizing the copper and lead adsorption sites on iron-coated sand. From the batch experiment results, the copper and lead ions could be removed simultaneously by the iron-coated sand in the competition adsorption system. The interaction between copper, lead ions and iron oxide on sand surface was primarily the chemical bonds. The maximum adsorption capacities of iron-coated sand for copper and lead were 0.259 mg Cu/g-sand and 1.211 mg Pb/g-sand, respectively. The presence of humic acid led to increase the adsorption of copper and lead. Results from column experiments indicated that the copper ions, lead ions and humic acid could be removed completely before the breakpoint. Consequently, the iron-coated sand may be applied for the adsorption/filtration of metal ions and natural organic matters from water.

Spontaneous discharge and response characteristics of central otolith neurons of rats during postnatal development

To study the developmental profile of otolith-related vestibular nuclear neurons, their spontaneous activities and response dynamics were examined in decerebrate rats aged seven, 14, 21 and 84 (adult) days. Extracellular recordings were performed in the lateral and descending vestibular nucleus of animals held at the stationary position in the earth-horizontal or subjected to constant velocity off-vertical axis rotation, which selectively stimulates the otolith receptors. All neurons displayed sinusoidal position-dependent modulation in discharge rate, indicating their capability in coding spatial information during low-frequency head movement. Some neurons showed a full-cycle response to off-vertical axis rotation (non-clipped), while other neurons were silenced in discharge during parts of each rotary cycle (clipped). In seven-day-old rats, three-quarters of the responsive neurons sampled were clipped and the proportion progressively decreased to less than one-quarter in adult rats. In each age group, the clipped neurons discharged in approximately 60% of the stimulus cycle. Response gains of the neurons increased with age, reaching a plateau from 21 days of age for clipped neurons and 14 days for non-clipped neurons. The clipped neurons demonstrated higher response gains than the non-clipped neurons at or beyond 21 days of age. Spontaneous activities of the neurons at the stationary and earth-horizontal positions were analysed in relation to their response gains; a positive correlation was observed from 14 days of age onwards. Both types of neurons showed progressive increase in spontaneous activity as the rats matured, though the clipped neurons exhibited significantly lower resting rates than the non-clipped neurons at each of the age groups studied. Some neurons that responded to off-vertical axis rotation were not spontaneously active at the stationary position, but the proportion of these decreased significantly with age. The coefficient of variation of each age group showed a bimodal distribution, thereby allowing spontaneously active neurons to be assigned as regular or irregular. Though the vast majority of both the clipped and non-clipped neurons showed irregular discharge patterns at seven days of age, the overall population became more regular as the rats matured. Irregular neurons of young rats exhibited phase-stable and phase-shift responses, while those of older rats showed only the phase-stable response. This distinction was not observed amongst regular neurons over the ages studied. Our results reveal features of central otolith neurons that can be taken as signs of maturation during the first three postnatal weeks. These neuronal features provide the framework for the analysis of behaviours mediated by the otolith system during postnatal maturation.

Ginseng flowers stimulate progesterone production from bovine luteal cells

Our previous report first showed evidence that polysaccharides isolated from ginseng leaves obtained from Jilin, China possess luteotropic activities. In this study, we made further investigations on the root and flowers of Korean ginseng by means of the same bioassay system described briefly as follows. Frozen-thawed bovine luteal cells (1 x 10(5) cells/ml/well) in M199 were incubated in 24-well culture plates at 37 degrees C in a 5 % CO2 incubator. Ten microl of tested drugs with 1, 10 and 100 microg/ml were added into each well. After 4- and 24-hr incubation, the media were harvested and assayed for progesterone by an enzyme immunoassay. The production of progesterone from cells is the indicator for evaluating the action of tested drugs. Results showed that hot water extracts ofginseng flowers (GF-1) with 10 to 100 microg/ml significantly increased progesterone production, whereas those from ginseng root (GR-1) could not. Crude polysaccharides (GF-2) isolated from GF-1 is the active component and the small molecules (mw < 10,000 dalton) are excluded, indicating that the ginseng root has no luteotropic activities, but the polysaccharides of ginseng flowers have.

Comparison of microbial composition in the subgingival plaque of adult crowded versus non-crowded dental regions

It has been reported in the literature that certain species of bacteria (periodontopathogens) present in the subgingival plaque are associated with destructive periodontal disease. The purpose of this study was to investigate and compare the presence and proportional distribution of periodontopathogens in the subgingival plaque of adult crowded versus non-crowded dental regions. Thirty adult patients with anterior dental crowding were selected from the Orthodontic Clinic of the University of Pennsylvania. After orthodontic records were taken and the periodontal examination was performed, subgingival plaque samples were collected from crowded (experimental) and contralateral non-crowded regions (control) of each patient. The presence of 9 periodontopathic species, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Eikenella corrodens, Campylobacter rectus, Capnocytophaga species, Fusobacterium species, Peptostreptococcus micros, Porphyromonas gingivalis, and Bacteroides forsythus, was determined using culture and immunofluorescence techniques. The bacterial morphotype was also determined by the use of dark-field microscopy. It was found that supragingival plaque accumulation in crowded regions was significantly greater than in non-crowded regions. Analysis of the bacteria showed that the samples from crowded regions consistently contained more species of periodontopathogens than the samples from non-crowded regions. Morphologically, more spirochetes and motile rods were present in the crowded-region samples. In terms of the presence of individual periodontopathogens, Fusobacterium species, Capnocytophaga species, C rectus, and P micros were significantly more common in the crowded samples than in the non-crowded samples. It was concluded that: (1) more plaque accumulated in crowded areas; (2) more species of periodontopathogens were present in the subgingival plaque of crowded regions; (3) morphologically, more spirochetes and motile rods were present in crowded areas; and (4) Fusobacterium species, Capnocytophaga species, C rectus, and P micros were present more often in crowded areas than in non-crowded areas (P < 0.05).

Ergodicity and scars of the quantum cat map in the semiclassical regime

We study the quantum localization effect of the cat map manifested in the motions of statistical ensembles. Specifically, the coarse-grained entropy and time-averaged phase space distributions are investigated. For this purpose, an amended version of the Wigner function on the discretized phase torus is presented. We find that the time average of the coarse-grained Wigner function is scarred (antiscarred) along some short periodic orbits, and the heights (depths) of these scars (antiscars) decrease in a linear way with the Planck constant when the semiclassical limit is approached. The relationship between the scars observed here and those exhibited in the quasienergy eigenstates is discussed.

Adsorptive characteristics of cadmium and lead on the goethite-coated sand surface

This study was conducted to develop a heating process for coating crystalline goethite on the sand surface to utilize the adsorbent properties of the coating. Goethite-coated sand was investigated for adsorbing cadmium and lead ions from water by batch and column experiments. Chemical analysis (energy dispersive analysis of X-ray, EDAX) was used for characterizing the cadmium and lead adsorption sites on goethite-coated sand. From the results of the batch experiments, the cadmium and lead ions could be adsorbed effectively on the goethite-coated sand. Maximum adsorption capacity values for cadmium and lead were 319, 704 micrograms-Cd/g-sand and 702, 1241 micrograms-Pb/g-sand at pH = 5.0, pH = 6.0, respectively. The interaction between cadmium, lead ions and goethite on sand surface was primarily to cause the chemical bonding. Results from column experiments indicated that the cadmium and lead ions could be removed higher than 95% before 110, 130 and 66, 85 numbers of pore volume of influent were treated at pH = 5.0 and pH = 6.0, respectively.