A55 YOU ARE WHAT YOUR GREAT, GREAT GRANDPARENTS PARENTS ATE: PRE-NATAL GLYPHOSATE EXPOSURE INDUCES DYSBIOSIS, METABOLIC DYSFUNCTION AND BEHAVIOURAL ABNORMALITIES THREE GENERATIONS AFTER EXPOSURE

Background

Canada is one of the most prolific users of the herbicide glyphosate (tradename Roundup®), with over 25 million kilograms purchased annually. Glyphosate is commonly applied pre-harvest as a desiccant, leading to higher residues in many foods consumed within Canada, including wheat, cereals, legumes, and soy products. Glyphosate prevents the synthesis of aromatic amino acids by inhibiting the Shikimate pathway, which, besides killing weeds, can also inhibit bacterial growth and promote bacterial dysbiosis. Dysbiosis has been associated with multiple disease states, including intestinal inflammation and metabolic dysfunction, which both include anxiety, depression, and cognitive dysfunction as co-morbidities.

Purpose

My goal is to clarify if there are harmful glyphosate effects on the gut bacteriome, resulting in altered metabolic health, damaging intestinal inflammation, and behaviour changes through the gut-brain axis. We explored two environmentally relevant doses throughout our experiments: (1) the acceptable daily intake currently set by the Environmental Protection Agency (EPA) (1.75mg/kg body weight/day); (2) the North American dose calculated with a registered dietician based on literature values of glyphosate within items that make up a typical Canadian diet (0.01mg/kg body weight/day.)

Method

Breeding pairs consisting of Muc2^-/- (colitis susceptible) and Muc2^+/- (littermate control) mice were exposed to glyphosate during pregnancy. A subset of each generation underwent behavioural testing to characterize anxiety, memory, and locomotor activity. Animals also underwent metabolic testing, including oral glucose and insulin tolerance tests. Only the parental generation of animals received glyphosate. In total, three generations of animals were raised.

Result(s)

Our results show that healthy mice whose great-grandparents were exposed to glyphosate at levels currently deemed safe by the EPA exhibited decreased locomotor activity. Furthermore, mice whose parents were exposed to either North American or EPA glyphosate levels exhibit symptoms of metabolic dysfunction in healthy and colitis-susceptible mice, including higher fasting blood glucose, an inability to efficiently clear glucose and impaired insulin response. Additionally, Muc2^-/- mice whose parents were exposed to levels of glyphosate found within the North American diet during pregnancy showed significant impairments in working memory.

Conclusion(s)

This study is the first to highlight the transgenerational effects of glyphosate at levels previously deemed safe for human exposure on locomotor activity, working memory and metabolism. Additionally, this study highlights how environmental toxins within our food system, such as glyphosate, may play a vital role in the etiology of many diseases in healthy and colitis-susceptible populations by promoting a sedentary lifestyle, metabolic dysfunction, and behavioural deficits.

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Disclosure of Interest

None Declared

Small molecule delivery across a perforated artificial membrane by thermoreversible hydrogel poloxamer 407

Microperforations in the round window membrane have been suggested for enhancing the rate and reliability of drug delivery into the cochlea. Intratympanic injection, the most common delivery method, involves injecting therapy into the middle ear to establish a reservoir from which drug diffuses across the round window membrane into the cochlea. This process is highly variable because (i) the reservoir, if liquid, can lose contact with the membrane and (ii) diffusion across the membrane is intrinsically variable even with a stable reservoir. To address these respective sources of variability, we compared the thermoreversible hydrogel poloxamer 407 (P407) to saline as a drug carrier and studied the effect of membrane microperforations on drug diffusion rate. We used Rhodamine B as a drug proxy to measure permeance across an artificial membrane in a horizontal diffusion cell. We found that permeance of Rhodamine B from a saline reservoir was an order of magnitude higher than that from a P407 reservoir across unperforated membranes. Moreover, permeance increased with total perforation cross-sectional area regardless of number of perforations (p < 0.05 for all saline-based experiments), but the same association was not found with P407. Rather, for a P407 reservoir, only a large perforation increased permeance (p < 0.001), while multiple small perforations did not (p = 0.749). These results confirm that for drug dissolved in saline, multiple small perforations can effectively enhance diffusion. However, for drug dissolved in P407, larger perforations are necessary.

Sensory nerve degeneration in a mouse model mimicking early manifestations of familial amyloid polyneuropathy due to transthyretin Ala97Ser

AIMS

Sensory nerve degeneration and consequent abnormal sensations are the earliest and most prevalent manifestations of familial amyloid polyneuropathy (FAP) due to amyloidogenic transthyretin (TTR). FAP is a relentlessly progressive degenerative disease of the peripheral nervous system. However, there is a lack of mouse models to replicate the early neuropathic manifestations of FAP.

METHODS

We established human TTR knock-in mice by replacing one allele of the mouse Ttr locus with human wild-type TTR (hTTR^wt ) or human TTR with the A97S mutation (hTTR^A97S ). Given the late onset of neuropathic manifestations in A97S-FAP, we investigated nerve pathology, physiology, and behavioural tests in these mice at two age points: the adult group (8 - 56 weeks) and the ageing group (> 104 weeks).

RESULTS

In the adult group, nerve profiles, neurophysiology and behaviour were similar between hTTR^wt and hTTR^A97S mice. By contrast, ageing hTTR^A97S mice showed small fibre neuropathy with decreased intraepidermal nerve fibre density and behavioural signs of mechanical allodynia. Furthermore, significant reductions in sural nerve myelinated nerve fibre density and sensory nerve action potential amplitudes in these mice indicated degeneration of large sensory fibres. The unaffected motor nerve physiology replicated the early symptoms of FAP patients, that is, sensory nerves were more vulnerable to mutant TTR than motor nerves.

CONCLUSIONS

These results demonstrate that the hTTR^A97S mouse model develops sensory nerve pathology and corresponding physiology mimicking A97S-FAP and provides a platform to develop new therapies for the early stage of A97S-FAP.

A Magnetometer Based on a Spin Wave Interferometer

We describe a magnetic field sensor based on a spin wave interferometer. Its sensing element consists of a magnetic cross junction with four micro-antennas fabricated at the edges. Two of these antennas are used for spin wave excitation while two other antennas are used for detection of the inductive voltage produced by the interfering spin waves. Two waves propagating in the orthogonal arms of the cross may accumulate significantly different phase shifts depending on the magnitude and direction of the external magnetic field. This phenomenon is utilized for magnetic field sensing. The sensitivity attains its maximum under the destructive interference condition, where a small change in the external magnetic field results in a drastic increase of the inductive voltage, as well as in the change of the output phase. We report experimental data obtained for a micrometer scale Y₃Fe₂(FeO₄)₃ cross structure. The change of the inductive voltage near the destructive interference point exceeds 40 dB per 1 Oe. The phase of the output signal exhibits a π-phase shift within 1 Oe. The data are collected at room temperature. Taking into account the low thermal noise in ferrite structures, we estimate that the maximum sensitivity of the spin wave magnetometer may exceed attotesla.

Spatial fluctuations of fluid velocities in flow through a three-dimensional porous medium

We use confocal microscopy to directly visualize the spatial fluctuations in fluid flow through a three-dimensional porous medium. We find that the velocity magnitudes and the velocity components both along and transverse to the imposed flow direction are exponentially distributed, even with residual trapping of a second immiscible fluid. Moreover, we find pore-scale correlations in the flow that are determined by the geometry of the medium. Our results suggest that despite the considerable complexity of the pore space, fluid flow through it is not completely random.

Clinical feasibility of a novel biphasic osteochondral composite for matrix-associated autologous chondrocyte implantation

OBJECTIVE

Matrix-associated autologous chondrocyte implantation has been used to treat cartilage defects. We developed a biphasic cylindrical osteochondral composite construct for such use, and conducted this study to determine its feasibility for treating osteochondral lesions in human knees.

METHOD

Ten patients with symptomatic osteochondral lesions at femoral condyles were treated by replacing pathological tissue with the construct of dl-poly-lactide-co-glycolide, whose lower body was impregnated with β-tricalcium phosphate and served as osseous phase. The construct had a chamber to load double-minced autologous cartilage, serving as source of chondrocytes. Osteochondral lesion was drill-fashioned a pit of identical dimension as the construct. Chondrocyte-laden construct was press-fit to fill the pit. Postoperative outcome was evaluated using Knee Injury and Osteoarthritis Outcome Score (KOOS) scale up to 24 months. Magnetic resonance image was taken, and sample tissue was collected with second-look arthroscopic needle biopsy at 12 months. Outcome parameters were primarily safety of surgery, and secondarily postoperative change in KOOS and regeneration of hyaline cartilage and cancellous bone.

RESULTS

No patient experienced serious adverse events. Postoperative mean KOOS in "symptoms" subscale had not changed significantly from pre-operation until 24 months; whereas those in the other four subscales were significantly higher than pre-operation at 12 and 24 months. Second-look arthroscopy showed completely filled grafted sites, with regenerate cartilaginous surfaces flushed with surrounding native joint surface. Microscopically, regenerated cartilage appeared hyaline.

CONCLUSION

This novel construct for chondrocyte implantation is safe for surgical application in knee. It repairs osteochondral lesions of femoral condyles by successful regeneration of hyaline cartilage.

50-Hz magnetic field induces EGF-receptor clustering and activates RAS

PURPOSE

In a previous study, we found that exposure to a 50 Hz magnetic field (MF) could activate stress-activated protein kinase (SAPK) and P38 mitogen-activated protein (MAP) kinase (P38 MAPK) in Chinese hamster lung (CHL) fibroblast cells, and simultaneous exposure to a 'noise' MF of the same intensity inhibited these effects. In order to explore the possible target sites and upstream signal transduction molecules of SAPK and P38 MAPK, and further validate the interference effects of 'noise' MF on 50 Hz MF, the effects of MF exposure on clustering of epidermal growth factor (EGF) receptors and Ras protein activation were investigated.

MATERIALS AND METHODS

CHL cells were exposed to a 50 Hz sinusoidal MF at 0.4 mT for different durations, and clustering of EGF receptors on cellular membrane and Ras protein activation were analyzed using immunofluorescence confocal microscopy and co-precipitation technology. EGF treatment served as the positive control.

RESULTS

The results showed that, compared with sham-exposed cells, exposure to a 50 Hz MF at 0.4 mT for 5 min slightly induced EGF receptor clustering, whereas exposure for 15 min enhanced receptor clustering significantly. Corresponding to receptor clustering, Ras protein was also activated after exposure to the 50 Hz MF. Exposure to a 'noise' MF (with frequency ranges from 30 - 90 Hz) at the same intensity and durations, did not significantly affect EGF receptor clustering and Ras protein. However, by superimposing the 'noise' MF, receptor clustering and Ras activation induced by 50 Hz MF were inhibited.

CONCLUSION

The results suggested that membrane receptors could be one of the most important targets where extremely low frequency (ELF) MF interacts with cells, and Ras may participate in the signal transduction process of 50 Hz MF. Furthermore, a 'noise' MF could inhibit these effects caused by ELF-MF.

Deleterious effects of MRI on chondrocytes

OBJECTIVE

To assess how magnetic fields (MFs), with or without concurrent radio frequency (RF), influence chondrocytes and knee joint repair, we applied an MF strength via magnetic resonance imaging (MRI) slightly greater than the frequently used dosage in the clinics and examined the effects of these treatments in vitro on human chondrocytes and in vivo in pigs.

METHODS

Human chondrocytes were directly exposed to a 3-tesla (T) magnetic field (MF group) or a 3-T static magnetic field plus 125.3 MHz radio frequency (MF+RF group), and cell proliferation, apoptosis, cytosolic Ca2+ ([Ca2+]i) fluxes and expression of the apoptosis-related proteins of the treated cells were examined to assess the effects of the treatments. In the pig study, we examined the effects of the treatments on the recovery of surgically damaged pig knees.

RESULTS

A 3-T static MF and RF suppressed cell growth and induced apoptosis through p53, p21, p27 and Bax protein expression. In the pig model, we found that MRI surveillance had a deleterious effect on the recovery of the damaged knee cartilage.

CONCLUSION

Magnetic strength, with or without concurrent RF, suppressed chondrocyte growth in vitro and affected recovery of damaged knee cartilage in vivo in the pig model. These results may be specific to the parameters used in this study and may not apply to other situations, field strengths, forms of cartilage injury, or animal species.

Modulation of cortical activity as a result of task-specific practice

This report aims to examine the role of task-specific practice in the modification of finger force enslaving and to provide empirical evidence for specific EEG frequency bands accompanying such practice may be an end-effectors dependent phenomenon. Nine handed naïve subjects without any training in music participated in a pre- and post-practice sessions separated by 12 practice sessions. Subjects performed a series of isometric force production tasks at 10% and 50% maximum voluntary contraction (MVC) with two rates of force development separately by index and ring fingers. Task-specific practice aimed at suppressing the contribution of neighboring fingers was achieved via visual feedback of force traces. Behavioral data (accuracy of force production and amount of force enslaving) and EEG data in frequency domain obtained via Morlet Wavelet transforms were analyzed. The major behavioral finding is that task-specific practice significantly enhanced the accuracy of force production and individuated control of the "most enslaved" ring finger (P<0.01), but not the index finger. The major novel EEG findings are: (a) modulation of EEG activity within alpha band (8-12 Hz) in the central area of the brain as a function of practice was similar for both fingers and (b) after practice, modulation of EEG activity within gamma (30-50 Hz) band was end-effectors specific. Both behavioral and EEG patterns suggest an effect of task-specific practice on the reduction of force enslaving and that modulation of practice-related plasticity in the human cortex is end-effectors dependent phenomena.

Expression of the serine protease, matriptase, in breast ductal carcinoma of Chinese women: correlation with clinicopathological parameters

Matriptase is a serine protease expressed by cells of surface epithelial origin, including epithelial breast tumor cells. Matriptase cleaves and activates proteins implicated in the progression of cancer and represents a potential prognostic and therapeutic target. The aim of this study was to examine matriptase expression in breast tumors of Chinese women and to identify its clinicopathological correlations. Immunohistochemical analysis of matriptase was performed in tissue microarrays of 251 breast tumors including 30 fibroadenomas, 59 ductal carcinomas in situ (DCIS), 38 grade I invasive ductal carcinomas (IDC), 79 grade II IDC, and 45 grade III IDC. The matriptase scores were significantly higher in the tumors than their non-tumor counterparts (178+/-12 for fibroadenoma; 275+/-11 for DCIS; 299+/-10 for grade I IDC; 251+/-10 for grade II IDC; and 314+/-11 for grade III IDC). In cases of IDC, matriptase scores were significantly correlated with tumor staging and nodal staging. Our findings demonstrate that matriptase is over-expressed in breast ductal carcinoma of Chinese women. It therefore may be a good biomarker for diagnosis and treatment of malignant breast tumors.

A Non-biotin Polymerized Horseradish-peroxidase Method for the Immunohistochemical Diagnosis of Canine Distemper

This report describes a modified non-biotin polymerized horseradish peroxidase (HRP) immunohistochemical method for the diagnosis of canine distemper virus (CDV) infection from formalin-fixed, paraffin wax-embedded tissues. This method confirmed infection in seven of eight (87.5%) suspected cases. Labelled CDV antigen was observed in the following sites: cerebrum, cerebellum, meninges, glial cells, neurons, vascular endothelium, periventricular areas and pericytes, and choroid plexus; grey and white matter and central canal of the spinal cord; renal pelvis and tubular epithelium, and urinary bladder epithelium; macrophages and lymphocytes in splenic white pulp and lymph nodes; skin epidermis; bronchiolar epithelium and alveolar macrophages; hepatic Kupffer cells, and gastric and intestinal mucosal epithelium; stratified squamous epithelium of the tongue and oesophagus. With the non-biotin HRP detection system, pretreatment by autoclaving followed by microwave heating gave better labelling results than did microwave pretreatment alone. No obvious difference was noted between the labelling results produced by the non-biotin HRP detection system and the Super Sensitive Link-Label IHC detection system.

Expression of EMMPRIN and matriptase in esophageal squamous cell carcinoma: correlation with clinicopathological parameters

Extracellular matrix metalloproteinase inducer (EMMPRIN) and the type II transmembrane serine protease, matriptase, are expressed in several human cancers and play an important role in tumor progression. The aim of the present study was to investigate the immuno-staining patterns of EMMPRIN and matriptase in patients with esophageal squamous cell carcinomas (SCC) and correlate the percentage tumor staining with tumor differentiation and clinical parameters. EMMPRIN and matriptase immunoreactivity was seen on the cell membrane and in the cytoplasm of tumor cells in all 41 cases of esophageal SCC evaluated. The percentage tumor staining of EMMPRIN was 48 +/- 3% for well differentiated, 73 +/- 3% for moderately differentiated, and 92 +/- 3% for poorly differentiated esophageal SCC. Higher percentage tumor staining with EMMPRIN correlated significantly with poorly differentiated esophageal SCC (P < 0.05). The percentage tumor staining with matriptase correlated significantly with tumor differentiation (52 +/- 3% for well differentiated, 85 +/- 2% for moderately differentiated, and 88 +/- 3% for poorly differentiated esophageal SCC). Additionally, higher percentage tumor staining with matriptase was significantly correlated with the advanced N and M stages (P < 0.05). Our results demonstrate that EMMPRIN and matriptase are over-expressed in esophageal SCC and are correlated with advanced clinicopathological stages. Pharmacological agents targeting EMMPRIN and matriptase expressions may be beneficial in the treatment of esophageal SCC.

Increasing expression of fascin in renal cell carcinoma associated with clinicopathological parameters of aggressiveness

AIM

To determine whether higher expression of fascin, an actin-bundling protein associated with motility, in conventional renal cell carcinoma (RCC) is associated with more advanced stages of the disease.

METHODS

Immunohistochemical analysis of fascin expression was performed in tissue microarrays of 108 RCCs including 55 clear cell RCCs (CRCCs), 39 CRCCs with granular cell differentiation (GRCCs), 8 CRCCs with sarcomatoid differentiation (SRCCs) and 6 metastatic RCCs.

RESULTS

The expression of fascin was undetectable in normal renal tubules of all control cases. However, among the 108 RCC cases, fascin immunoreactivity was seen on the cell membrane and cytoplasm. The average immunostaining score for fascin was 128/400 in grade I, 170/400 in grade II, 207/400 in grade III, and 323/400 in grade IV RCC. The average immunostaining score of fascin was 187/400 for stage T1, 205/400 for stage T2, 288/400 for stage T3, and 355/400 for stage T4 cases of RCCs. Higher fascin scores in RCC were significantly correlated with higher T and N stages and nuclear grade. In addition, the fascin scores in GRCC (368+/-19) and SRCC (263+/-21) were significantly higher than in CRCC (95+/-18).

CONCLUSIONS

Our findings demonstrate for the first time that increased expression of fascin is associated with clinicopathological parameters of aggressiveness in patients with RCC. Fascin may be a novel biomarker for diagnosis and treatment of RCC.

Practice-related modulations of force enslaving and cortical activity as revealed by EEG

OBJECTIVE

To examine the role of practice in the modification of force enslaving and motor-related cortical potentials using finger force production tasks. This study follows-up previous studies in our laboratory using experienced piano players.

METHODS

Two experiments were performed. In Expt. 1, 6 subjects participated in a pre and post EEG session separated by 12 practice sessions which were conducted 3 days a week for 4 weeks. With visual feedback regarding the accuracy of force output, subjects produced one of two force levels with either their ring or index finger. Experiment 2 followed a similar procedure to that of Expt. 1 with additional visual feedback to the degree of finger independency. Both behavioral (isometric force output) and EEG data preceding and accompanying force responses were measured.

RESULTS

In Expt. 1 we found that forced enslaving increased along with improved accuracy following 4 weeks of practice. We found a reduction of motor potential (MP) amplitude for the index but not the ring finger following practice. Experiment 2 showed an increase in accuracy and reduction in force enslaving after practice with adequate feedback. The amplitude of MP for the index finger also decreased after practice as in Expt. 1. In contrast, the amplitude of MP for the ring finger increased after practice.

CONCLUSIONS

The present study extends our earlier work with piano players and shows the role of practice in modifying behavioral and cortical measures. The concluding theme emergent from our studies is that individuated finger control is not hard-wired, but rather plastic and greatly influenced by deliberate practice.

SIGNIFICANCE

This research supports the idea that experience and practice are associated with changes in behavioral and EEG correlates of task performance and have clinical implications in disorders such as stroke or dystonia. Practice-related procedures offer useful approaches to rehabilitation strategies.

Expression of apoptosis-related markers and HER-2/neu in thymic epithelial tumours

AIMS

To correlate the expression of a series of apoptotic and oncogene markers (including p53, Bcl-2, BAX, Bcl-XL, p21WAF,1/CIP1, cyclin D1, HER-2/neu) in thymic epithelial tumours with histological type, stage and resectability and to determine whether the information on HER-2/neu would be valuable in identifying patients who are eligible for anti-HER-2/neu treatment.

METHODS AND RESULTS

Immunohistochemical stains were performed on 16 cases of non-neoplastic thymus, 63 thymomas and 17 thymic carcinomas. Fluorescence in-situ hybridization (FISH) for HER2 was performed to validate the gene amplification. Eighteen thymomas were positive for p53 and 14 of them were low-expressors, with positive cells below 10%. All thymic carcinomas revealed over-expression of p53 with positive cells either between 10% and 50% or >50%. The expression of p53 correlated with histological type and stage in thymoma. In both thymoma and thymic carcinoma, there was a statistically significant correlation between p53 status and resectability, with low expressors having a higher likelihood of being resectable. Thymic carcinomas, regardless of the histological subtypes, uniformly expressed Bcl-2, while thymomas showed no or only weak cytoplasmic immunoreactivity. Most thymomas and thymic carcinomas were negative for Bcl-XL, p21WAF,1/CIP1 and cyclin D1. The expression of BAX was inconsistent among different histological types. Nine thymic carcinomas revealed membranous positivity for HER-2/neu, but no HER2 gene amplification could be demonstrated by FISH in any of the cases.

CONCLUSIONS

p53 and Bcl-2 are more implicated in the development of thymic carcinoma than thymoma. The higher level of p53 expression and the strong immunopositive pattern of Bcl-2 in thymic carcinomas have potential value in the differential diagnosis and prediction of aggressiveness and resectability. On account of the absence of HER2 amplification, patients would probably not benefit from anti-HER-2/neu treatment.

ELF magnetic fields induce internalization of gap junction protein connexin 43 in Chinese hamster lung cells

We have previously demonstrated that exposure of Chinese hamster lung (CHL) cells to 50 Hz magnetic fields (MFs) and/or 12-O-tetradecanoylphorbol-3-acetate (TPA)-inhibited gap junctional intercellular communication (GJIC). To explore and compare the mechanisms of GJIC inhibition induced by extremely low frequency (ELF) MF and TPA, the number and localization of connexin 43 (C x 43) were studied. The localization of C x 43 was determined with indirect immunofluorescence histochemical analysis and detected by confocal microscopy after exposing CHL cells to 50 Hz sinusoidal magnetic field at 0.8 mT for 24 h without or with TPA (5 ng/ml) for the last 1 h. The C x 43 levels in nuclei and in cytoplasm were examined by Western blotting analysis. The results showed that the cells exposed to MF and/or TPA displayed individual plaques at regions of intercellular contact, which were fewer than the normal cells in number, while the number of C x 43 in cytoplasm increased and congregated near the nuclei. Western blot analysis further demonstrated the quantity of changes in location of Cx43. These results suggest that reduction of C x 43 at regions of intercellular contact may be one of the mechanisms of GJIC inhibition induced by ELF MF.

Millimeter wave exposure reverses TPA suppression of gap junction intercellular communication in HaCaT human keratinocytes

The effect of 30.16 GHz millimeter wave (MMW) exposure at 1.0 and 3.5 mW/cm2 on gap junction intercellular communication (GJIC) was studied in cultured HaCaT keratinocytes, using the fluorescence recovery after photobleaching (FRAP) technique and laser confocal scanning microscopy to follow the intracellular movement of 5,6-carboxyfluorescein diacetate dye. While MMW exposure alone for 1 h at either 1.0 or 3.5 mW/cm2 did not affect GJIC, MMW exposure in combination with 5 ng/ml TPA treatment reversed TPA induced suppression of GJIC. Exposure at 1.0 mW/cm2 resulted in a partial reversal, and exposure at 3.5 mW/cm2 resulted in essentially full reversal of the TPA suppression.

Modulated cortical control of individual fingers in experienced musicians: an EEG study. Electroencephalographic study

OBJECTIVE

The present research was designed to address the nature of interdependency between fingers during force production tasks in subjects with varying experience in performing independent finger manipulation. Specifically, behavioral and electroencephalographic (EEG) measures associated with controllability of the most enslaved (ring) and the least enslaved (index) fingers was examined in musicians and non-musicians.

METHODS

Six piano players and 6 age-matched control subjects performed a series of isometric force production tasks with the index and ring fingers. Subjects produced 3 different force levels with either their index or ring fingers. We measured the isometric force output produced by all 4 fingers (index, ring, middle and little), including both ramp and static phases of force production. We applied time-domain averaging of EEG single trials in order to extract 4 components of the movement-related cortical potentials (MRCP) preceding and accompanying force responses.

RESULTS

Three behavioral findings were observed. First, musicians were more accurate than non-musicians at reaching the desired force level. Second, musicians showed less enslaving as compared to non-musicians. And third, the amount of enslaving increased with the increment of nominal force levels regardless of whether the index or ring finger was used as the master finger. In terms of EEG measures, we found differences between tasks performed with the index and ring fingers in non-musicians. For musicians, we found larger MRCP amplitudes at most electrode sites for the ring finger.

CONCLUSIONS

Our data extends previous enslaving research and suggest an important role for previous experience in terms of the independent use of the fingers. Given that a variety of previous work has shown finger independence to be reflected in cortical representation in the brain and our findings of MRCP amplitude associated with greater independence of fingers in musicians, this suggests that what has been considered to be stable constraints in terms of finger movements can be modulated by experience.

SIGNIFICANCE

This work supports the idea that experience is associated with changes in behavioral and EEG correlates of task performance and may have clinical implications in disorders such as stroke or focal hand dystonia. Practice-related procedures offer useful approaches to rehabilitation strategies.

The role of sub-maximal force production in the enslaving phenomenon

When individuals perform a force task involving only one finger, they involuntarily move other fingers as well. This phenomenon is referred to as the enslaving force or the interdependency of fingers. Given that previous literature on the enslaving force has focused on maximal isometric force production, the present research was designed to study the role of sub-maximal force production in the enslaving phenomenon. To this end, we examined behaviorally three levels of force production with a constant rate of force development. We also examined the temporal organization of enslaving separating the achievement of the desired force (ramp phase) and its maintenance (static phase). During the static phase we found: (i) the amount of enslaving increased with the increment of nominal force level whether the index, middle, ring or little fingers were used as the master finger; (ii) enslaving is strongest in the finger directly adjacent to the master finger; and (iii) in terms of enslaving, the index finger was more 'independent' than the other three fingers, regardless of nominal force produced, followed by the little, middle, and ring fingers. In terms of temporal organization, we found that the time-lag of activation of 'slave fingers' during the ramp phase was reduced as the amount of force level increased. Overall, our data suggest that enslaving effect is a task specific phenomenon and depends on the amount of force produced by the master finger.

Motor-related cortical potentials accompanying enslaving effect in single versus combination of fingers force production tasks

OBJECTIVES

This study examined behavioral indices and motor-related cortical potentials (MRCP) of the enslaving phenomenon (i.e. interdependency of finger movement) during isometric force production tasks using each of the four fingers separately and in combination. We examined MRCP preceding force production and those during the achievement of the desired force (ramp phase) and its maintenance (static phase).

METHODS

Our experimental design systematically controlled the isometric force output, including both ramp and static phases of force production. We applied time-domain averaging of electroencephalographic single trials in order to extract 3 components of MRCP (Bereitshaftspotential, motor potentials, and motor monitoring potentials) preceding and accompanying force responses.

RESULTS

We report two major findings. First, we found the index finger to be more independent, accurate, and to display the larger MRCP amplitude whereas the ring finger was more dependent, less accurate, and displayed smaller MRCP amplitude. Second, adding the neighboring finger when the ring finger produced the task significantly reduced its dependency on uninvolved fingers and increased the accuracy of both ramp and static phases which was not the case with the index finger. The amplitude of MRCP was increased when the ring finger produced the task in combination as compared to when the ring finger performed the task in isolation. In contrast, the amplitude of MRCP was significantly reduced when the index finger produced the task in combination with other fingers when compared to when the index finger performed the task in isolation.

CONCLUSIONS

Overall, the amount of the fingers' dependency on the uninvolved fingers (e.g. amount of enslaving) during isometric force production tasks was inversely related with the amplitude of MRCP indicating the contribution of central mechanisms to the enslaving phenomenon.

Movement-related EEG potentials are force or end-effector dependent: evidence from a multi-finger experiment

OBJECTIVES

This study examined behavioral and electrocortical responses in producing 3 levels of force (25, 50 and 75% of MVC) at a constant rate of force development with each of 4 fingers both during the achievement of the desired force (ramp phase) and its maintenance (static phase). We were particularly interested in describing in more detail the interaction between nominal force and finger on various components of movement-related potential (MRP) associated with preparation and execution of isometric force production tasks.

METHODS

Our experimental design systematically controlled the rate of force development while nominal force level was experimentally manipulated during isometric force production tasks. We applied time-domain averaging of EEG single trials in order to extract 3 components of MRP (BP(-600 to -500); MP(-100 to 0); MMP) preceding and accompanying behavioral responses.

RESULTS

Overall, as in our previous research the effect of force per se was not reflected in the EEG components. However, we did find an interaction between finger and force level in both the Bereitshaftspotential (BP) and motor potential (MP) components of the movement-related potentials. While the middle, ring and little finger produced no differences in EEG components at any of the 3 force levels, the index finger did. We further correlated the force trajectory and the EEG time series with the highest correlations found in the lowest force level with the index finger. As the force level was increased, the correlation was significantly reduced.

CONCLUSIONS

Overall, the whole complex of MRP components and evolution of EEG time series during multi-finger isometric force production tasks reflect a combination of factors including the primary end-effector performing the task and interaction of end-effector and the amount of nominal force.

Thymoma is associated with an increased risk of second malignancy

BACKGROUND

An association between thymoma and second malignancy has been suggested but has not been validated. Whether the relation is due to treatment or to other thymoma-associated conditions is unclear.

METHODS

The authors studied 192 consecutive patients with thymoma and compared the incidence of second malignancies with those of 206 patients who underwent thymectomy for nonthymomatous conditions and 1426 patients with nasopharyngeal carcinoma (NPC). Detailed clinicopathologic features of thymoma patients with second malignancies were described.

RESULTS

Additional malignancies were detected in 15 of 192 patients (8%) during their clinical courses. The risk for those patients was significantly greater compared with the risk for patients with nonthymomatous conditions (adjusted odds ratio [OR], 3.81; 95% confidential intervals [95%CI], 1.05-13.81; P = 0.042) and patients with NPC (adjusted OR, 4.89; 95%CI, 2.26-10.53; P < 0.0001) after adjustment for age, gender, length of follow-up, myasthenia gravis, and radiation therapy. The occurrence of second malignancies did not correlate with histologic type or stage of thymoma, radiation therapy, or myasthenia gravis.

CONCLUSIONS

Thymoma is associated with an increased risk of second malignancy. The association cannot be attributed to the effect of thymectomy or radiation therapy. Patients with thymoma, even if it is benign, should be followed regularly to facilitate the early detection of other malignancies.

ELF magnetic field inhibits gap junctional intercellular communication and induces hyperphosphorylation of connexin43 in NIH3T3 cells

The effects of extremely low frequency (ELF) magnetic field on gap junctional intercellular communication (GJIC), protein levels, and phosphorylation of connexin43 (Cx43) were studied in NIH3T3 cells. The suppression of GJIC by 24 h, 50 Hz, 0.8 mT ELF magnetic field, 2 h, 3 ng/ml 12-O-tetradecanoylphorbol-13-acetate (TPA), or ELF combined with TPA treatment was confirmed by the fluorescence recovery after photobleaching (FRAP) analysis with a confocal microscope. The results showed that ELF or TPA exposure induced 50-60% inhibition of GJIC (P < 0.01). ELF combined with TPA enhanced the inhibition of GJIC. Western blot analysis using Cx43 specific antibodies showed obviously decreasing non phosphorylated Cx43 (P(0)) induced by ELF and/or TPA exposure. On the other hand, cells treated with ELF and/or TPA displayed a hyperphosphorylated Cx43 band (P(3)). However, there was no obvious changes in the level of Cx43 protein. The results implied that the P(3) band appeared to result from phosphorylation of P(0). But it remains possible that upon the ELF exposure P(0) is converted to P(1), P(2) or both and that P(3) is formed from P(1) or P(2) resulting in the observed hyperphosphorylation pattern. From the present study, we conclude that ELF magnetic field inhibits GJIC and the main mechanism is the hyperphosphorylation of Cx43.

Thymoma is associated with an increased risk of second malignancy

BACKGROUND

An association between thymoma and second malignancy has been suggested but has not been validated. Whether the relation is due to treatment or to other thymoma-associated conditions is unclear.

METHODS

The authors studied 192 consecutive patients with thymoma and compared the incidence of second malignancies with those of 206 patients who underwent thymectomy for nonthymomatous conditions and 1426 patients with nasopharyngeal carcinoma (NPC). Detailed clinicopathologic features of thymoma patients with second malignancies were described.

RESULTS

Additional malignancies were detected in 15 of 192 patients (8%) during their clinical courses. The risk for those patients was significantly greater compared with the risk for patients with nonthymomatous conditions (adjusted odds ratio [OR], 3.81; 95% confidential intervals [95%CI], 1.05-13.81; P = 0.042) and patients with NPC (adjusted OR, 4.89; 95%CI, 2.26-10.53; P < 0.0001) after adjustment for age, gender, length of follow-up, myasthenia gravis, and radiation therapy. The occurrence of second malignancies did not correlate with histologic type or stage of thymoma, radiation therapy, or myasthenia gravis.

CONCLUSIONS

Thymoma is associated with an increased risk of second malignancy. The association cannot be attributed to the effect of thymectomy or radiation therapy. Patients with thymoma, even if it is benign, should be followed regularly to facilitate the early detection of other malignancies.

Plurihormonal pituitary adenomas: immunostaining of all pituitary hormones is mandatory for correct classification

AIMS

We studied the clinicopathological characteristics of plurihormonal pituitary adenomas.

METHODS AND RESULTS

The study material included 167 plurihormonal adenomas, which consisted of 31% of the surgically removed pituitary adenomas that we collected during a 12-year period. The mean age of patients with plurihormonal adenoma was 45.7 years (range 13-75 years). There were 86 men and 81 women. All tumours were fully classified by immunohistochemical staining for seven pituitary hormones or subunits. Thirty immunohistochemical subtypes of plurihormonal adenomas were recognized. Hormonal symptoms were present in 70% of patients, while serum hormonal levels were increased in 89% of patients. Most patients had symptoms related to only one of the hormones and only 7% of patients had symptoms related to two hormones. The most common hormonal symptom was acromegaly (50%); symptoms related to hyperprolactinaemia ranked second (20%). Double immunostaining of all the possible combinations of the hormones was performed in 30 selected tumours, and they all showed mixtures of hormones in individual adenoma cells in any hormonal combinations studied. The latter finding supported the view that plurihormonal adenomas are monomorphous adenomas.

CONCLUSIONS

Plurihormonal adenomas are common pituitary adenomas. Immunohistochemical staining of all pituitary hormones is mandatory for correct classification.

A clinicopathologic study of 81 patients with ependymomas and proposal of diagnostic criteria for anaplastic ependymoma

Optimal histologic criteria for the classification of and grading of ependymomas, including their anaplastic forms, remain elusive. This is especially true because of the poor correlation of these criteria with clinical outcome. The aim of this study was to identify the histopathologic parameters that could distinguish different prognostic groups of patients with ependymomas. Eighty-one patients with ependymal tumors, including those originally diagnosed ependymomas, anaplastic ependymomas and myxopapillary ependymomas, were enrolled in this study. Thirteen histologic parameters, including hypercellularity, nuclear pleomorphism, mitoses, endothelial proliferation, necrosis, clear cell, thrombi, dystrophic calcification, psammoma bodies, bone, cartilage, Rosenthal fibers and MIB-1 labeling index (LI), were evaluated in each patient and correlated with clinical outcome. We assigned one score for each histopathologic parameter evaluated and used a stepwise selection method with entry model based on the significance of the log-rank statistic to formulate a scoring model. Four parameters were chosen in this process, including mitoses > or = 4/10 hpf (1.7/mm2), hypercellularity, endothelial proliferation and necrosis. The sum of these four parameters (scores) was the histopathologic score of the tumor. The progression-free survival (PFS) and overall survival (OS) of patients with histopathologic scores 0 and 1 were significantly better than those with histopathologic scores 2, 3 and 4 (p < 0.001 and p = 0.005, respectively). Because of the latter finding, we proposed that anaplastic ependymoma could be diagnosed by the presence of any two of the aforementioned four parameters. Multivariate analyses including clinical and histopathologic variables showed that histopathologic score > or = 2 and subtotal resection were the factors related to increased risk of recurrence, while histopathologic score > or = 2 was the only factor related to overall survival. Based on the above findings, we concluded that histopathology is an important prognostic indicator for patients with ependymomas.

Influence of carbon disulphide on hydroxyl radicals in the phenanthroline chemiluminescence system

We investigated the effects of carbon disulphide (CS2) on hydroxyl radical generation using the phenanthroline chemiluminescence system. The influence of CS2 on the phenanthroline chemiluminescence system without CuSO4 and vitamin C were tested. The results showed that CS2 enhanced the emission intensity of chemiluminescence and advanced the peak time of the chemiluminescence. There was a dose-effect relationship between CS2 concentrations (0-160 mg/ml) and chemiluminescence peak intensity (r = 0.955, R2 = 0.913, p = 0.003), as well as CS2 concentrations and peak time (r = -0.927, R2 = 0.860, p = 0.008). The enhanced chemiluminescence induced by CS2 could be inhibited by thiourea, and the inhibition rate gradually deceased along with increasing CS2 concentration (r = -0.816, R2 = 0.666, p = 0.048). When the system was free of CuSO4 and vitamin C, CS2 also induced the emission of chemiluminescence intensity. We conclude from these results that CS2 can induce the phenanthroline chemiluminescence system to generate hydroxyl radicals and advance the peak time, and that thiourea can inhibit the effect. The mechanism may be explained by a catalytic effect of CS2 directly on H2O2.

Human papillomavirus type 18 in colorectal cancer

Human papillomaviruses (HPVs) have been recognized as the etiological agent of warts, and they may also be associated with many cancers. HPV-18 is very common both in genital papillomas and in large bowel cancer. The relation between HPV-18 infection and natural course of colorectal cancer has not been fully defined. In this study, normal mucosa and colorectal cancer tissue were evaluated for the presence of HPV gene to determine whether or not HPV was involved in the development of colon neoplasm. The DNA extracted from colon tissue was screened for HPV by polymerase chain reaction (PCR) to amplify the viral gene fragment. These PCR products were digested with restriction enzyme, and Southern blotting was then performed to confirm the existence of HPV-18. The nucleotide sequence related to HPV-18 DNA was detected in 53% (10/19) of the normal mucosa specimens and in 84% (16/19) of the colorectal cancer specimens. The correlation between cancer samples and positive rate of HPV-PCR was statistically significant by chi-square test (p < 0.01). These data indicate that HPV-18 can infect the normal mucosa of the colon, and that this infection may be a risk factor for the development of colorectal cancer. The presence of HPV-18 DNA in patients with colorectal cancer suggests that the pathogenesis of colorectal cancer includes viral involvement.

Real-time dynamic telepathology through the Internet: evaluation of a new and economic technology at Taipei Veterans General Hospital

BACKGROUND

Computer-aided, digitalized telepathology was introduced about 10 years ago and is gaining acceptance as a mode of providing pathology to remote site. The usefulness of telepathology for remote diagnosis of histology, cytology and frozen section has been evaluated in USA, Europe and Japan. In Taiwan, the use of telepathology for pathological diagnosis is still rare. In order to evaluate the potential use of this technique, we undertook the study using commercialized and low-cost microscopy, personal computer and software on routine biopsy material.

METHODS

Sixty prostatic sextant transrectal needle biopsies, including 30 cases of adenocarcinoma and 30 cases of benign lesions, were retrieved retrospectively. The real-time dynamic images were transmitted to the remote site via internet and reviewed by a senior uropathologist who was unaware of the diagnosis. The diagnoses made at the remote site were correlated to the final diagnoses of the cases.

RESULTS

All malignant specimens (30/30) were correctly diagnosed by this method. Only one benign case (1/31) of nonspecific granulomatous prostatitis was misdiagnosed as poorly differentiated carcinoma.

CONCLUSIONS

Our results show that this method is a good way for teleconsultation. Further studies on other types of specimen worth encouragement for both intra- and inter-institutional consultation.

Bending strength and holding power of tibial locking screws

The bending strength and holding power of two types of specially designed tibial locking devices, a both-ends-threaded screw and an unthreaded bolt, were studied and compared with four types of commercially available tibial interlocking screws: Synthes, Howmedica, Richards, and Osteo AG. To test bending strength, the devices were inserted into a high molecular weight polyethylene tube and loaded at their midpoint by a materials testing machine to simulate a three point bending test. Single loading yielding strength and cyclic loading fatigue life were measured. To test holding power, the devices were inserted into tubes made of polyurethane foam, and their tips were loaded axially to measure pushout strength. The devices were tested with two different densities of foam materials and two different sizes of pilot holes. Insertion torque and stripping torque of the screws were measured first. Pushout tests were performed with each screw inserted with a tightness equal to 60% of its stripping torque. Test results showed that the yielding strength and the fatigue life were related closely to the inner diameter of the screws. The stripping torque predicted the pushout strength more reliably than did the insertion torque. All tested devices showed greater holding power in the foam with the higher density and with the smaller pilot holes. The both-ends-threaded screw had the highest pushout strength and a satisfactory fatigue strength. The unthreaded bolt had the highest fatigue strength but only fair holding power. Clinical studies of the use of these two types of locking devices are worthwhile.

Spindle cell and mixed spindle/lymphocytic thymomas: an integrated clinicopathologic and immunohistochemical study of 81 cases

Forty-three cases of spindle cell thymoma (medullary, WHO type A) and 38 cases of mixed spindle/lymphocytic thymoma (WHO type AB) were studied for their clinicopathologic and immunohistochemical characteristics. Three histologic patterns of spindle cell thymoma were observed: short-spindled (57%), long-spindled (31%), and micronodular (12%). The short-spindled variant was composed of oval to short spindle cells commonly arranged in a hemangiopericytic or microcystic pattern. The long-spindled variant chiefly consisted of fibroblast-like epithelial cells mimicking fibrohistiocytic neoplasms. The micronodular variant was characterized by small nests of short spindle cells dispersed among a lymphoid stroma with frequent germinal centers. All kinds of spindle cell could be admixed with lymphocyte-rich "cortex"-like areas to constitute mixed spindle/lymphocytic thymomas. Immunohistochemically, the epithelial cells in up to 70% of the short-spindled and long-spindled variants of spindle cell thymoma and 90% of mixed spindle/lymphocytic thymomas were positive for CD20, whereas the epithelial cells in all micronodular spindle cell thymomas were negative. All of the spindle cell thymomas and most of the mixed spindle/lymphocytic thymomas in this study were found in stages I and II. Follow up of the patients did not disclose relapse or mortality directly resulting from the tumors. However, the prognosis of stage I and II spindle cell and mixed spindle/lymphocytic thymomas did not significantly differ from those of stage I and II thymomas of other types by a stage-matched survival analysis. Our data showed that spindle cell and mixed spindle/lymphocytic thymomas are distinctive in histologic pattern and immunohistochemical profile. When interpreted within the context of staging, spindle cell and mixed spindle/lymphocytic thymomas presenting in stages I and II most likely behave in an indolent fashion.

Lack of mutations of BCL6 and BCL10 genes in mucosa-associated lymphoid tissue lymphomas of the orbital adnexa

Knowledge regarding the molecular pathogenesis and progression of mucosa-associated lymphoid tissue (MALT) lymphomas of ocular adnexa is limited. Eleven cases of ocular MALT lymphoma were analyzed by clonal rearrangement of antigen receptor genes using Southern blot hybridization. Polymerase chain reaction-single stranded conformational polymorphism analysis and DNA sequencing was utilized to analyze the mutations of BCL6 and BCL10 genes. Clonal rearrangement of immunoglobulin heavy genes was found in all 11 patients. No point mutation was found in BCL6 or BCL10 genes in any of the samples analyzed. We suggest that mutations of BCL6 and BCL10 genes are rare in low-grade MALT lymphoma of ocular adnexa and are unlikely to be involved in the pathogenesis of the disease. But the role of alterations of both BCL6 and BCL10 genes in the disease progression of low-grade MALT lymphoma require additional study.

EEG correlates of finger movements as a function of range of motion and pre-loading conditions

OBJECTIVES

The present study was designed to obtain additional data regarding the differential influence of kinematic parameters and different nominal force levels upon components of movement-related cortical potentials (MRP) during index finger flexion.

METHODS

The absolute nominal force level of discrete movements was varied while the rate of force development remained constant within a given task. This was accomplished by utilizing a pre-loading experimental design at different ranges of index finger motion (25, 50 and 75 degrees), so that the movement kinematic profiles (velocity and acceleration) and rate of force development remained constant within each given range of motion. Time-domain averaging of EEG single trials was applied in order to extract 3 movement-related potentials (BP(-600 to -500), BP(-100 to 0) and N(0 to 100)) preceding and accompanying 25, 50 and 75 degrees of unilateral finger movement with no pre-load (0 g), small pre-load (100 g) and large pre-load (200 g).

RESULTS

The range of motion differentially influenced the amplitude of early (BP(-600 to -500)) and late (BP(-100 to 0)) MRP components spatially localized over frontal, central and parietal areas. The amplitude of the N(0 to 100) component localized over parietal and frontal areas was also sensitive toward experimental manipulations of the range of motion. Overall, the amplitude of N(0 to 100) localized over the central area was the only MRP component that was sensitive to the amount of pre-loading. However, within a given range of motion, none of the pre-loading conditions (0, 100 or 200 g) influenced the amplitude of MRP components.

CONCLUSIONS

The central finding was that an increase in nominal force production within a given range of motion did not influence MRP components when the rate of force development was held constant. It becomes especially apparent with strict control of kinematic and kinetic movement parameters that different methods of adding weight to the index finger performing the same movement patterns have different consequences for EEG correlates as reflected in the amplitude and spatial distribution of MRP. The range of motion of index finger flexion was the primary kinematic variable that consistently influenced MRP components both preceding and accompanying movement execution.

Tubulocystic clear cell adenocarcinoma arising within the prostate

Neoplasms resembling ovarian common epithelial-type tumors, including clear cell adenocarcinomas, rarely occur in the lower urinary tract of men. When they do, they develop in the urethra or urinary bladder. We report a case of such a tumor arising within the prostate of a 47-year-old man. The tumor was a cystic mass in the left posterolateral region of the prostate. Histologically, the tumor was chiefly composed of tubulocystic and papillary glands lined by glycogen-rich, cuboidal or hobnail cells with clear to eosinophilic cytoplasm. The tumor cells were strongly positive for pan-cytokeratin, low molecular weight cytokeratin, and epithelial membrane antigen, and focally positive for high molecular weight keratin. The tumor did not immunohistochemically express prostate-specific antigen (PSA) and prostatic acid phosphatase. Serologically, the patient had increased levels of CA125 instead of PSA. The clinical as well as the pathologic features are consistent with a clear cell adenocarcinoma as seen in the female genital tract rather than a typical prostatic adenocarcinoma.