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Difficult conversations about isms, power, privilege, and oppression are an essential part of social work education, and they present unique challenges for students and faculty. The current study examined students’ and faculty’s perceptions of the safety of the classroom and the competence of the faculty in facilitating difficult conversations at a graduate school of social work in New York City. Student and faculty versions of a survey were distributed to both groups. Results indicated students rated the experience of having difficult conversations at the school significantly more negatively than the faculty did. The majority of respondents expressed the need for courses and training to be more fluent in having difficult conversations. Future directions are discussed based on the findings.

Ridaifens (RIDs), a novel series of tamoxifen derivatives, exhibit a potent growth-inhibitory effect against numerous tumor cells regardless of the expression of estrogen receptors, and are thus promising candidates as novel anti-tumor drugs. RID-B is a first generation RIDs, and inhibits the proliferation of several tumor cell lines. However, the potentially growth inhibitory effect of RID-B against hepatoma cells, and the detailed mechanism underlying RID-B-mediated tumor cell death remain to be elucidated. The purpose of the current study was to evaluate the anti-proliferative effect of RID-B against hepatoma cells. The anti-proliferative effect of RID-B against human hepatoma Huh-7 cells was investigated by cell proliferation assay using WST-1 reagent, and caspase-3 activity was evaluated by using specific fluorescent substrate. In addition, DNA fragmentation in Huh-7 cells induced by RID-B was estimated by terminal deoxynucleotidyl transferase dUTP nick-end labelling assay, and binding of RID-B to double-stranded DNA was confirmed by mass spectrometry. RID-B (0.5, 1 and 2 µM) inhibited the growth of Huh-7 cells, seemingly dose-dependently, but did not inhibit the growth of normal primary rat hepatocytes in the same concentration range. Furthermore, the caspase-3 activity of Huh-7 cells was increased by RID-B (0.5 and 5 µM), and the anti-proliferative effect of RID-B (1 µM) on Huh-7 cells was partially suppressed by the addition of the caspase inhibitor, Z-VAD-FMK. Additionally, RID-B (10 µM) directly bound to double-stranded DNA, and the addition of DNA suppressed RID-B-mediated cell growth inhibition and DNA fragmentation in Huh-7 cells. From these data, it may be concluded that RID-B inhibited cell growth and induced apoptosis via activating caspase-3 and binding to DNA directly, leading to DNA fragmentation in hepatoma cells.

Genetic structure of masu salmon Oncorhynchus masou populations in Hokkaido was examined by analysing mtDNA NADH dehydrogenase subunit 5 gene (561 bp) of 382 individuals collected from 12 rivers, in which there were no records of artificial release. Analysis of molecular variance showed that between groups level and between populations within-group level explained each c. 10% of genetic variance. In neighbour-joining tree, four populations located in southern Hokkaido were clustered into a single group; however, other populations did not form any clear clusters. Fu’s FS, Tajima’s D and a mismatch distribution test indicated a sudden expansion of population in the entire population of Hokkaido and the northernmost population of Chiraibetsu, which was genetically close to the southern Hokkaido group. The Sea of Japan and southern rivers, including those of southern Hokkaido, seem to have served as refugia for masu salmon during glacial periods, and their dispersal and straying in interglacial periods affected the genetic structure of masu salmon populations in Hokkaido.

This paper presents an unsupervised approach of integrating speech and visual information without using any prepared data. The approach enables a humanoid robot, Incremental Knowledge Robot 1 (IKR1), to learn word meanings. The approach is different from most existing approaches in that the robot learns online from audio-visual input, rather than from stationary data provided in advance. In addition, the robot is capable of learning incrementally, which is considered to be indispensable to lifelong learning. A noise-robust self-organized growing neural network is developed to represent the topological structure of unsupervised online data. We are also developing an active-learning mechanism, called "desire for knowledge," to let the robot select the object for which it possesses the least information for subsequent learning. Experimental results show that the approach raises the efficiency of the learning process. Based on audio and visual data, they construct a mental model for the robot, which forms a basis for constructing IKRI's inner world and builds a bridge connecting the learned concepts with current and past scenes.

This paper presents a new method for continuous and incremental learning and recognition based on self-organized incremental neural networks. It is available in the fluctuating environment where the number of recognition classes cannot be defined. In this method, the learning process and recognition process are not separated. This method can acquire concept when multiple feature vectors of new input object come, and then can recognize it using previously acquired concept. We experiment an examples of life-long semi-supervised learning tasks in real world. In the result, the proposed method was able to learn and recognize 104 objects incrementally, non-stop, and in real time

A mixture of vermiculite (hydrous silicates) and paper pulp (waste product of paper industry) was used as a supporting material for the in vitro photoautotrophic micropropagation of plantlets. Sweet potato was used as a model plant to find out the appropriate proportion of vermiculite and paper pulp for the optimum growth of the plantlets. The plantlets grown in the conventional supporting material, agar, were used as the control. The study revealed that in all aspects, the plantlets grown in vermiculite mixed with 30% (w/w) paper pulp exhibited the highest growth performance. The shoot and root fresh mass were x2.7 greater than those in agar (control); the leaf, stem and root dry mass were also greater and at least two fold in this treatment compared with those in the control. The net photosynthetic rate per plantlet was highest in this treatment, and on day 20 it was 15.3 µmol CO(2) h(-1) as compared with 9.8 µmol CO(2) h(-1) in the control. The growth of both shoots and roots decreased gradually with the increase or decrease of percentage of paper pulp in the supporting material. In general, the growth was significantly poorer in the plantlets grown in 100% vermiculite than that in vermiculite mixed with 30% paper pulp but still greater than in the control. The porosity of the supporting materials increased with the increase in the percentage of paper pulp in the supporting material. After transplanting to the ex vitro condition the survival percentage did not vary significantly (90-100%) among the treatments, except in control where it was only 73%. The number of unfolded leaves and the stem height were similar among the treatments except those in the control.

The purpose of this study was to evaluate intracoronary thrombi in the culprit lesions in patients with acute myocardial infarction (AMI) by angioscopy, and to compare them with clinical and angiographic features. We angioscopically observed the culprit coronary lesions in 66 patients with AMI (55 males and 11 females, 63.9±15.4 years old) just before interventional therapy. Thrombi were observed in 42 of 66 lesions (64%), namely, red thrombi in 16, mixed thrombi in 15, white thrombi in 11. In patients with complete obstruction (TIMI grade 0 and I), red thrombi were more frequently observed than mixed or white thrombi. On the other hand, in patients with incomplete obstruction (TIMI grade II and III), white thrombi were more frequently observed than the others. Angiographically, haziness and filling defect were significantly more frequently observed in patients with red thrombi than the others (p<0.05). The distance from proximal side branch to thrombi tended to be longer in patients with red thrombi than the others. The time from onset of AMI tended to be longer in patients with white thrombi than the others. These results suggest that blood flow may be an important determinant of thrombi characterization.

A comparative study was conducted to optimize the vegetative growth of sweet potato (Ipomoea batatas L. (Lam), cv. Beniazuma) plantlets cultured in vitro in five different types of supporting materials: agar matrix (a seaweed derivative; Kanto Chemical Co. Inc., Tokyo), gellan gum (a Pseudomonas derivative; Kanto Chemical Co. Inc., Tokyo), vermiculite (a kind of hydrous silicates), a mixture of vermiculite and cellulose fiber (Florialite; Nisshinbo Industries, Inc., Tokyo) and cellulose plug (Sorbarod; Baumgartner Rapiers SA., Switzerland). Single nodal cuttings were cultured photoautotrophically (without any sugar in the medium and with enriched CO2 and high photosynthetic photon flux) for 21 d on MS basal medium. Plantlets exhibited the greatest growth when Florialite was used as supporting material. The leaf and root fresh and dry mass were 2.4× and 2.9×, and 2.2× and 2.8× greater, respectively, than those of the plantlets grown in the agar matrix (control). Plantlets cultured in Sorbarod supporting material exhibited the second greatest fresh and dry mass of leaves and roots followed by vermiculite and gellan gum supporting material. The most interesting feature was the development of a large number of fine lateral roots from the main adventitious root in the Florialite treatment. Among the treatments, the highest net photosynthetic rate was evident in the Florialite grown plantlets. The percent porosity of the supporting materials was highest in Sorbarod followed by Florialite and vermiculite. Plantlets transplanted from the Florialite supporting material exhibited the highest acclimatization percentage followed by that of the Sorbarod treatment.

The isolation and characterization of eight polymorphic microsatellite loci from a Japanese flounder partial genomic library are reported. The eight markers isolated in this study were highly polymorphic and their positions on the linkage genome map of the Japanese flounder were determined. Therefore, they are useful for ecological studies of wild populations. These markers are more effective than other markers with no information of chromosomal locations.

To enable the study of the population genetics of the tree sparrow (Passer montanus), which is distributed in many islands of Japan, nine polymorphic microsatellite loci were isolated from 32 individuals. The number of alleles per locus ranged from 2 to 17, and observed heterozygosities ranged from 0.1250 to 0.9375. In eight of the nine loci, the heterozygosities were not significantly different from those expected from Hardy-Weinberg equilibrium. Cross-species amplification in the russet sparrow (P. rutilans) was successful with all primer sets, which were highly polymorphic, suggesting these markers are useful for the population genetics of genus Passer.

This paper presents an approach (SOINN-DTW)for recognition of motion (gesture) that is based on the Self-Organizing Incremental Neural Network (SOINN) and Dynamic Time Warping (DTW). Using SOlNN's function of eliminating noise in the input data and representing the distribution of input data, SOINN-PTW method approximates the output distribution of each state in a self-organizing manner corresponding to the input data. The proposed SOINN-DTW method enhances Stochastic Dynamic Time Warping Method (Nakagawa. 1986). Results of experiments show that SOINN-DTW outperforms HMM, CRF. and HCRF in motion data.

We present a new approach for online incremental word acquisition and grammar learning by humanoid robots. Using no data set provided in advance, the proposed system grounds language in a physical context, as mediated by its perceptual capacities. It is carried out using show-and-tell procedures, interacting with its human partner. Moreover, this procedure is open-ended for new words and multiword utterances. These facilities are supported by a self-organizing incremental neural network, which can execute online unsupervised classification and topology learning. Embodied with a mental imagery, the system also learns by both top-down and bottom-up processes, which are the syntactic structures that are contained in utterances. Thereby, it performs simple grammar learning. Under such a multimodal scheme, the robot is able to describe online a given physical context (both static and dynamic) through natural language expressions. It can also perform actions through verbal interactions with its human partner.

Summary We have developed the first set of trinucleotide and tetranucleotide markers for the Japanese flounder, Paralichthys olivaceus. One hundred and sixty-seven polymorphic trinucleotide and tetranucleotide microsatellites were isolated using clones derived from two libraries. Of almost 200 000 clones analysed, 0.5% presented trinucleotide or tetranucleotide repeat regions. Among the trinucleotide repeats analysed in this study, the most frequent one was (CAG)n and the most common tetranucleotide repeat was (GATA)n. The position of the new markers in the genetic linkage map was determined. Markers were evenly distributed along the P. olivaceus linkage groups, without distinction between the kinds of repeats and library of origin. The markers isolated in this study contribute significantly to the genetic linkage map of the Japanese flounder.

Fractal image coding is a computationally expensive method. This paper does some improvement for traditional no search method and quadtree method, then combines the improved no search method with improved quadtree method to greatly speed up the fractal encoding process and hold high reconstruction fidelity. Some other time-consuming parts of fractal coding are redesigned and accelerated with new techniques. Experiments on standard images show that the proposed scheme can reduce encoding time greatly with only a little loss of approximation quality.

This paper introduces a method for the animation of things based on the observation of natural phenomena and on the synthesis of their behavioral patterns using machine learning methods. The natural phenomena to be animated is recorded using a video camera, and its characteristics behavior is captured. A data sequence representing the subject behavior is obtained from the captured video. By learning the inherent structure in the feature space of some sample data, the learned model can synthesize a novel data sequence from the existing sequences. The generated sequences of behavioral patterns could differ from every original data sequence but preserve characteristics of the subject behavior. We demonstrate the natural animation synthesis through such behavioral pattern sequences, and produce some realistic animation which depict the subject.

A description is given of an automatic microorganism recognition and identification method, using image processing based on an expert system, for application in a micro-manipulator system. Since microorganisms under a microscope all appear different, are moving, and have time-dependent shapes, the conventional pattern-matching method used for industrial products can be applied. The proposed method is based on segmentation of the microorganisms, taking advantage of characteristic segment features that are independent of individual size and length. Complicated shapes are divided into simple-shaped segments such as lines, circles, ovals, etc. The relation between segments is described in the database of the expert system. Microorganisms can then be expressed simply by a set of segments and so that their individual differences can be avoided. Tracking the movement of a microorganism by its image is also shown. >

An automatic organisms recognition and identification method for a micromanipulator system, using image processing based on an expert system, is described. The proposed method is based on the organism image segmentation method (OISM), which takes advantage of characteristic segment features that are independent of individual size and length. The complicated shapes of the organisms are divided into basic shape segments such as lines, circles, ovals, etc. The relation between segments are analyzed and described in the database of the expert system automatically. Organisms are then expressed simply by a set of segments, so that their individual differences are avoided. Tracking the movement of an organism by its image is also shown. The effectiveness of this method is confirmed by experimental results. >

A new pattern recognition method is proposed for handwritten alphabet and digit characteristics. The feature point distribution of a standard pattern is mapped onto that of a distorted pattern, through a modified self-organizing map (SOM). The distorted pattern is recognized based on similarity between both feature point distributions. The modified SOM has the following advantages. First, the number of feature points is small, and these are classified into several groups. Second, the mapping is carried out in the variable ring shape region to find a suitable pairing of the feature points. Third, the feature points are selected from both the standard and the distorted patterns to avoid any vibration. Finally, neighborhoods are selected along lines of the patterns. These improvements can provide stable and fast feature point mapping. Computer simulations demonstrated that the proposed method can adapt to a variety of pattern distortions. >

This paper describes briefly an algorithm both for real-time facial image recognition in unconstrained indoor environments and a human like agent image synthesis which responds to the recognition results. Our simple but effective image recognition algorithm can recognize facial images from moving images, choose one primal face and track the primal face in real-time. Therefore, the agent can gaze/glance/etc., at the primal face (the interacting user) during the process. It means a "facial contact" or an "eye contact" can be achieved between the user and the synthesized moving agent, which is very important for friendly human interfaces.

An expert system for the recognition and counting of cells using image processing for mass production of interferon beta is described. The biological cells which make interferon beta are taken from animals and cultured on microcarriers, plastic balls/beads 150-200 mu m in diameter floating in a culture solution. Cell images are obtained through a microscope connected to a TV camera. The number of cells in the culture vessel increases during a six-day period, and the expert system recognizes the state of cell growth during this time by means of image processing. The expert system is a more effective way to recognize cluster cells on densely grown/distributed beads from the gray image data than simple image processing. The creature image segmentation method was also applied, and it is shown that this method can recognize the cell shape and location, avoiding individual differences on the plastic balls. >

In order to submit queries to Web search engines, we have to carefully choose the suitable combination of keywords. Without rich background knowledge about keywords in Web documents, it is too difficult to find out invaluable URLs by search engines. Applying techniques of text data mining to Web resource discovery, we try to derive associative keywords by an extended association algorithm. We explain the interface of the Web resource discovery system using association rules, which are derived from the cluster of Japanese HTML pages in the text database. We discuss an evaluation of the Mondou system and Java applet order to visualize search results with multidimensional measurements.

F-wave normally varies in latency and waveform from one response to the next. But the number of identical responses in a series of F-waves may be increased with neurogenic atrophy consistent with a decreased number of motoneurons capable of responding to antidromic stimulation. They are called "repeater F-waves". We herein demonstrate some repeater F-waves observed in three patients with moderate or slight diabetic polyneuropathy. In their motor nerve conduction studies on the peroneal nerve the maximum conduction velocity was 33 m/sec in patient 1, 36 m/sec in patient 2 and 48 m/sec in patient 3. A total of 6 delayed indirect potentials were repeatedly evoked after nerve trunk stimulation. They fulfilled the characteristics of F-wave. Their conduction velocities in the leg segment were 27, 26, 23 m/sec in patient 1, 34, 33 m/sec in patient 2 and 46 m/sec in patient 3. Repeater F-waves are occasionally observed in patients with amyotrophic lateral sclerosis, cervical spondylosis or entrapment neuropathies, in which the number of motoneuron is decreased. In diabetic polyneuropathy some repeater F-waves were also observed in patients not only with moderate to severe neuropathy but also with normal nerve conduction. F-waves are generated by an antidromic backfiring of motor neurons, and they occur preferentially in large motor neurons. Larger motor neurons inhibit smaller axons through the activation of Renshaw cells. In our 3 patients conduction velocities of the repeated F-waves were all identical to the main component of M-wave. These observations reconfirmed the hypothesis that relatively large motor neurons generating F-waves are preferentially activated also in repeater F-waves.

In Rochester diabetic neuropathy research by Dyck et al., abnormal value in two or more nerves was introduced into the nerve conduction criteria of diabetic neuropathy. Polyneuropathy index-revised(PNI-R) is calculated as the mean percentage of the normal of 8 parameters on the motor nerve conduction studies. They were motor nerve conduction velocities in the forearm or leg segment and F-wave latencies after wrist or ankle stimulation concerning to the median, ulnar, peroneal and posterior tibial nerves. F-wave latencies were adjusted to 160 cm height and used reciprocals in comparison with normal values. To compare these two indices, first we obtained the normal limit(1st or 99th percentile value) of each parameter from the data of 62 healthy individuals. Then in 78 patients with diabetes mellitus number of abnormal nerves and the PNI-R were investigated. Abnormal values were frequently observed in the categories of motor nerve conduction velocities and F-wave latencies. Amplitude of compound muscle action potential (CMAP) or sensory nerve action potential(SNAP) in each nerve had a large standard deviation. In such parameters abnormal rate was extremely low, because the lower limit of normal being very small. Nevertheless, sigma CMAP which means the summation of amplitudes of 3 CMAPs had as high as 53% of abnormal rate. The coefficient of correlation between number of abnormal nerves and the value of PNI-R mounted up to -0.87. Instead, the coefficient of correlation of sigma CMAP or sigma SNAP, which means the summation of amplitudes of ulnar and sural SNAPs, with PNI-R were 0.65 and 0.79, respectively. In 14 patients PNI-R was normal and the number of abnormal nerves was 0 or 1. In 59 both categories were abnormal, and only in 5 they were not coincide. As to the clinical signs PNI-R had better correlation than number of abnormal nerves with vibration threshold or degree of Achilles tendon reflex. sigma CMAP is a convenient index to detect the existence and the degree of neuropathy. This index expresses the degree of neurogenic muscular atrophy, though it doesn't always advance parallel to the decrease in number of motor nerves. sigma SNAP had higher coefficient of correlation with PNI-R or number of abnormal nerves than sigma CMAP. In conclusion, abnormal PNI-R and abnormal value in two or more nerves are both useful and coincide with each other in the detection of diabetic neuropathy. The PNI-R is an excellent quantitative index, and the PNI-R corresponds well with the number of abnormal nerves. These observations indicate that the number of nerves with abnormal value is also available as a simple and semi-quantitative index of diabetic neuropathy.

In motor nerve conduction studies compound muscle action potentials (CMAPs) appear later than sensory nerve action potentials (SNAPs). This time lag originates from the conduction delay at the distal motor axon, neuromuscular transmission time and muscle action potential induction time. To investigate the latency difference between CMAPs and SNAPs we studied 46 healthy individuals, 46 patients with diabetes mellitus and 33 patients with carpal tunnel syndrome, using the lumbrical and interossei recording method. In this method the recording active electrode was placed on the 2nd lumbrical muscle and the reference electrode on the proximal palmar aspect of the index finger. Supramaximal stimulation was given to the median or ulnar nerve trunk at 9-cm proximal to the recording active electrode. The CMAP from the 2nd lumbrical muscle (L) and the SNAP from the digital nerve (N) were recorded after median nerve stimulation, and the CMAP from the 2nd interossei muscles (I) was recorded after ulnar nerve stimulation. The residual latency, which is arbitrary defined as the latency difference (L-N) in this study, was 1.38 +/- 0.15 (mean +/- SD) msec in healthy individuals. About 1 msec of the residual latency is regarded as the time for neuromuscular transmission and the time to evoke muscle activities. Thus, the conduction delay at the distal motor axon was calculated as about 0.4 msec in healthy individuals. The residual latency was relatively constant in 29 diabetic patients without conduction delay across the carpal tunnel, which was defined by the latency difference (L-I)or = 0.4 msec. Their sensory nerve conduction velocities (calculated from N latency) were always above 40 m/sec. On the other hand in diabetic patients with conduction delay across the carpal tunnel, which was defined by the latency difference (L-I)0.4 msec, the residual latency gradually increased as the sensory nerve conduction velocity decreased. Their sensory nerve conduction velocities were mostly less than 40 m/sec. The similar relationship was observed in patients with carpal tunnel syndrome without diabetes mellitus. We consider that the diabetic neuropathy alone doesn't cause the increase of the residual latency. Instead, severe conduction delay across the carpal tunnel decreases the N velocity and increases the residual latency. We can also regard the relationship between the latency difference (L-N) and N velocity as being in inverse proportion. Perhaps the increase of the residual latency was simply caused by the proportional decrease in the conduction velocity at the distal motor axon, not by the special mechanism concerning to the carpal tunnel syndrome. This paper presented the electrophysiological changes seen in the distal segment secondary to the proximal entrapment.

We investigated 117 patients with spasmodic torticollis who had visited us to seek for appropriate treatment in these 14 years. They were 71 men and 46 women, aged 44 +/- 14 (mean +/- SD) years, and suffered from this disorder during 4 +/- 5 years, maximum 26 years. Involuntary abnormal head positions, not only torticollis but also laterocollis and antero- or retrocollis, were contained in this study. Most of them were torticollis due to idiopathic focal dystonia. One or more courses of alcoholization therapy was accomplished in 82 patients who wished to be done. This therapy course consisted of about ten times totally of 99% ethanol injection to the motor point of two most hypertonic neck muscles, either side of the sternocleidomastoideus and the opposite side of the splenius in most cases, repeated every 2 or 3 weeks. One patient received as many as 98 times of this injection and resolved completely. Training to reinforce antagonistic muscles was also instructed. Twenty-one patients (26%) were resolved completely after this treatment. Fifty-four patients (66%) were ameliorated and satisfied partially, but 18 of them relapsed in 1 to 4 years after the treatment and were obliged to repeat one more course of this treatment. On the other hand, in five patients their torticollis improved under certain drug therapy alone. Sixteen patients (14%) gave up to continue the treatment within two months, and 14 patients (12%) dropped out before starting the therapy. This alcoholization therapy resulted in amelioration of torticollis in about 90% of the patients with a long effective period. Nevertheless, this alcohol injection is painful, and requires 5 to 6 months to be completed. In 2 patients who had already received many times of this injection, sudden hoarseness occurred one day immediately after the alcohol injection to the sternocleidomastoideus. This complication was presumably brought about by the unexpected infiltration of alcohol to the laryngeal area, located posterior to that muscle. They recovered in two months, but careful attention should be paid to the adverse effects. If botulinum toxin be available also in our country, we will be able to have another choice of therapy and the treatment of this disorder will become easier.

On the electrophysiological basis, extensor digitorum brevis(EDB) muscle is innervated electrophysiologically not only by deep peroneal nerve(DPN) but also by accessory deep peroneal nerve(ADPN), an anomalous branch of superficial peroneal nerve, with a prevalence of 17-28%. We investigated 23 patients who had both DPN and sufficient ADPN innervation to the EDB on the intramuscular distribution of DPN and ADPN innervation to the medial and lateral side of the EDB. Recording electrodes were placed on the medial and lateral edges of the EDB with a supramaximal stimulation to the anterior or lateral ankle, compound muscle action potential (CMAP) of DPN or ADPN innervation was recorded. In 19 patients (83%) the DPN innervation was larger than or equal to the ADPN innervation. Only in 4 patients (17%) the ADPN innervation obviously exceeded the DPN innervation. DPN enters to the EDB from the medial side, and ADPN from the lateral side of the EDB. In 16 patients(70%) the DPN innervation was relatively large and the ADPN innervation was relatively small at the medial side of the EDB, and vice versa at the lateral side of the EDB. These distributions were almost uniform in 5 patients(22%). This study clarified that a biased larger DPN innervation and smaller ADPN innervation to the medial side of the EDB, and vice versa to the lateral side of the EDB in the majority cases. In some cases diffuse innervation to the EDB was found.

The polyneuropathy index-revised(PNI-R), based on 8 electrophysiological parameters(conduction velocities and F-latencies), was constructed to obtain an overall estimation of peripheral nerve conduction in diabetic patients, taking PNI as a model. PNI was calculated as a mean percentage of the normal on 12 velocity or latency parameters on motor nerve conduction studies. PNI-R is composed of 8 parameters; motor nerve conduction velocities in the forearm or leg segment and F-wave latencies after wrist or ankle stimulation concerning to the median, ulnar, peroneal and posterior tibial nerves. F-wave latencies were adjusted to 160 cm height and used reciprocals to compare with the normal values. Subjects were 101 patients with diabetes mellitus. Correlation of PNI-R or PNI with other parameters or indices on conventional sensory and intrafascicular conduction studies or items concerning to the diabetes mellitus were studied. Coefficient of correlation between PNI-R and PNI was as high as 0.97. The mean value of PNI-R was 0.6% smaller than PNI. This was presumably due to the greater influence of the peroneal parameters, weighted more in PNI-R than in PNI. Peroneal nerve is known to be sensitive to various neuropathies, and is often damaged independently. Each parameter composing PNI-R had a close relationship with PNI-R itself. Mutual independence between 8 parameters was considered to be enough. Among neuropathic signs Achilles tendon reflex in particular, and among diabetic complications retinopathy in particular, had a high degree of correlation with PNI-R. These results were identical both with PNI-R and PNI. We can save 20-30% of time in measuring PNI-R as compared to measure PNI, and the usefulness of PNI-R was as well as PNI. Therefore, using PNI-R as substitute for PNI is considered to be appropriate in the evaluation of diabetic polyneuropathy. Between parameters concerning to the median nerve F-wave latency correlated less with PNI-R than motor nerve conduction velocity in the forearm segment. Presumably this was owing to an unrecognized subclinical carpal tunnel syndrome, often observed in patients with diabetes mellitus. PNI-R will be an excellent index to express the function of peripheral nerve conduction, which can be retarded by the axonal degeneration in diabetes mellitus.

Prevalence of median to ulnar anastomosis in the forearm(Martin-Gruber anastomosis; MGA) to the first dorsal interosseous(FDI), abductor digiti quinti (ADQ) and adductor pollicis(AP) was investigated. Subjects contained 106 patients with normal nerve conduction or patients with various neuropathies. Recording electrodes were placed on the motor point of FDI, ADQ and AP. Supramaximal stimulations were given to the median and ulnar nerves at the wrist or above the elbow. The diagnosis of MGA was made by the following criteria; amplitude of compound muscle action potential(CMAP) increased after elbow stimulation as compared with the wrist stimulation in median nerve conduction studies. The corresponding decrease in CMAP amplitude was found after above elbow stimulation as compared with the wrist stimulation in ulnar nerve conduction studies. No MGA was found in 80(75%) out of 106 patients. MGA to FDI was found in all 26 patients who had MGA. MGA to ADQ and AP was found in 11% and 10% of the patients, respectively. Only 8 out of 26 patients had MGA to all 3 muscles. In the presence of MGA median motor nerve conduction studies demonstrate larger CMAP, with a small initial positivity, after elbow stimulation than after wrist stimulation. And moreover, ulnar motor nerve conduction studies reveal a conduction block-like finding in the forearm. In this study MGA was found in 25% of the patient to FDI, in 11% to ADQ and in 10% to AP. Although a very small MGA might be overlooked in our method, such a small MGA doesn't mislead us into erroneous interpretation of motor nerve conduction studies.

In patients with carpal tunnel syndrome, varying degrees of demyelination and axonal degeneration occur in the median nerve. Only a few studies have examined axonal degeneration produced at proximal to the lesion. In this study proximal axonal degeneration was evaluated and compared with other parameters. In 40 consecutive CTS patient hands, distal latency (DL), compound muscle action potential amplitude (CMAP) and motor conduction velocity (MCV) were analyzed by conventional motor nerve conduction studies. Intrafascicular compound nerve action potential amplitude (N-CNAP) at the elbow after wrist simulation and its nerve conduction velocity (NCV) between wrist and elbow were also analyzed. The negative correlation of DL with CMAP was statistically significant (r = 0.577, p0.001). CMAP was correlated with either MCV (r = 0.537, p0.001) or N-CMAP (r = 0.710, p0.001). A significant correlation of MCV with NCV (r = 0.517, p0.001) was also indicated. There were no any other significant correlation among the parameters. In CTS the degree of demyelination and axonal degeneration influence the prognosis for nerve recovery after decompressive surgery. DL is mainly influenced by demyelination that results in conduction block and slowing at the carpal tunnel. CMAP and N-CNAP indicate the degree of axonal degeneration at distal and proximal to the compression site. As in electrophysiologic evaluation of mononeuropathies, proximal axonal degeneration is best assessed by both stimulation and recording electrode locationing proximal to the lesion. Recording of intrafascicular nerve action potential was a little invasive method, but it provided important informations. The negative correlation between DL and CMAP implies that distal axonal degeneration can occur in proportion to the conduction disturbance. Moreover, N-CNAP had a higher correlation with CMAP. The greater the distal axonal degeneration, the more the proximal axonal degeneration. Conduction velocity represents the velocity of the fastest conduction fiber, not the degree of axonal degeneration.

Median nerve conduction studies were performed by conventional and lumbrical/interossei recording methods. The former is composed of recordings of compound muscle action potential from abductor pollicis brevis (APB) and sensory nerve action potential from second digit (D) after wrist stimulation. In the latter the recording electrode was placed lateral to the midpoint of the 3rd metacarpal bone, and recorded compound muscle action potential from the 2nd lumbrical (2 L) and sensory nerve action potential from the digital nerve (N) after wrist stimulation. Subjects were 57 healthy individuals and 97 patients with diabetes mellitus. Particularly in diabetic patients values of coefficient of correlation between each measurement were high enough; i.e., r = 0.91 between latencies to 2 L and APB, r = 0.55 between amplitudes of 2 L and APB, r = 0.86 between amplitudes of N and D. Corresponding measurements by conventional method and lumbrical/interossei method were identical in the values of coefficient of correlation between measurements. The characteristics of lumbrical/interossei method are to be able to record compound muscle action potentials and nerve action potential from the same electrode. In this study values obtained by lumbrical/interossei method showed identical correlation between measurements to the corresponding ones by conventional method. In conclusion recordings of APB and D by conventional method can be replaced with the recordings of 2 L and N by lumbrical/interossei method in the evaluation of diabetic neuropathies.

In order to clarify the suitability of sensory nerve action potential(SNAP) in the evaluation of diabetic polyneuropathy, we studied measurements of SNAPs in the median, ulnar and sural nerves. Subjects were 253 patients with non-insulin dependent diabetes mellitus; 167 men and 86 women, aged 58.2 +/- 12.8(mean +/- SD) years old. Their diabetic history was 10.2 +/- 8.6 years. SNAPs were recorded antidromically from index finger, little finger and lateral to the Achilles tendon, respectively. Twenty-eight patients, in whom any one of the SNAPs couldn't be obtained, were already excluded from this study. The polyneuropathy index (PNI) was calculated from 12 indices concerning to the velocity or long distance latency in motor nerve conduction studies of 4 nerves. The PNI is known to be an excellent index to express the degree of diabetic polyneuropathy. Amplitude and conduction velocity in each nerve was 28.6 +/- 15.6 microV and 46.2 +/- 7.4 m/sec in the median nerve, 26.7 +/- 15.8 microV and 47.0 +/- 6.5 m/sec in the ulnar nerve, 13.1 +/- 6.5 microV and 43.1 +/- 6.0 m/sec in the sural nerve, respectively. The coefficient of correlation of the measurements between median and ulnar nerves was larger than other assortment of nerves. The coefficient of correlation of each measurement with PNI was around 0.40 in the amplitude and around 0.55 in the conduction velocity. Nevertheless, the mean value of the 3 nerves had a higher coefficient of correlation with PNI; 0.48 in the amplitude and 0.60 in the conduction velocity. SNAP measurements of a single nerve are often largely affected by the inter-individual differences, inter-nerve differences or measuring errors. But the mean value of the 3 nerves will be better in exploring the degree of diabetic polyneuropathy. Evaluation of diabetic polyneuropathy by SNAPs will be best achieved by using the mean value of these 3 nerves.

Ulnar nerve can be stretched with the elbow flexed position. To avoid elbow flexed position in patients with ulnar neuropathy at the elbow we used an athletic elbow supporter. We herein demonstrate a 31-year-old man with right ulnar neuropathy at the elbow whose neuropathy was resolved by using this supporter only at night. He had complained of weakness and paraesthesia in the ulnar side of his right hand. Nerve conduction studies of right ulnar nerve revealed decrease in the amplitude of compound nerve action potentials and a severe motor nerve conduction block with apparent conduction delay around the ulnar groove. A diagnosis of ulnar neuropathy at the elbow was done and we recommended him to wear an athletic elbow supporter at night. Paraesthesia of his right hand improved in a few days after starting this therapy. Three months later paraesthesia was resolved. One year later grip power of his right hand increased to 35 kg from 20 kg, and the conduction block at the elbow completely disappeared. Compound nerve action potentials, recorded at the segment of wrist to above elbow and wrist to finger, were improved equally. These observations suggest that the conduction block at the elbow entrapment site and the distal axonal degeneration gradually recovered together.

In motor nerve conduction studies we sometimes encounter a small initial positive deflection (IPD) of the compound muscle action potential (CMAP). This potential represents a volume conduction from nearby muscles other than the objective muscle. We demonstrated recordings of motor nerve conduction studies from two patients with carpal tunnel syndrome (CTS). In patients with CTS IPDs can be recorded from a surface electrode above the abductor pollicis brevis when intense stimuli to the median nerve provoked a stimulus spread to the ulnar nerve. However, without this stimulus spread to the ulnar nerve, IPDs can be observed by contraction of median nerve innervated muscles. In the CTS thenar branch of the median nerve is apt to be more severely damaged than lumbrical branch. In such an occasion volume conduction from the lumbrical muscles is relatively large, which gives rise to the IPD in the CMAP recorded from abductor pollicis brevis. We reported two cases of IDPs originated from lumbrical muscles. The peak latencies were identical between IDP of abductor pollicis brevis recording and negative potential of lumbrical recording. These potentials didn't change by median nerve stimulation at the elbow 3 msec after the ulnar nerve stimulation at the wrist (collision technique). Finally, we repeat that IPDs in the median nerve conduction studies can be originated from not only the stimulus spread to the ulnar nerve but also the median nerve innervated lumbrical muscles in patients with CTS.

We report a 49-year-old tetraplegic woman with meningeal carcinomatosis secondary to breast cancer. Serial nerve conduction studies in the extremities revealed that the amplitudes of the sensory nerve action potentials (SNAP) and the compound muscle action potentials (CMAP) decreased rapidly within a few days after her admission. Plasma exchanges were done four times and restored the SNAP amplitudes to normal range. The CMAP amplitudes were also increased, but not to the normal range. These electrophysiologic changes were not associated with clinical improvement. Our patient's tetraplegia may be associated with a combination of two different mechanisms; reversible axonopathy caused by humoral factors that can be removed by plasma exchange, and irreversible radiculopathy due to direct cancer cell invasion.

We investigated characteristics of segmental motor conduction in the median and the ulnar nerves. Subjects were 55 individuals with normal conduction of the upper extremity and 71 patients with diabetes mellitus. Mean polyneuropathy index (PNI), which was determined as a mean percentage of the normal for 6 indices concerning to the conduction velocity in the upper limb, was 99.0% in the normal group and 85.6 % in the diabetic group on the mean. In the normal group distal latency was longer in the median nerve than in the ulnar nerve, and the conduction time between Erb's point and the wrist was longer in the ulnar nerve than the median nerve both in men and women. In the diabetic group these differences were accentuated; that means the distal latency was relatively more prolonged in the median nerve and the conduction time between Erb's point and the wrist was much longer in the ulnar nerve. Prolonged distal latency in the median nerve of women and conduction delay between Erb's point and the wrist in the ulnar nerve of men altogether resulted in the gender difference in the median minus ulnar F-wave latency after wrist stimulation in the diabetic group. Carpal tunnel segment of the median nerve and the elbow segment of the ulnar nerve are known to be common entrapment sites. This phenomenon of accentuated conduction delay in these common entrapment sites might be considered as a sort of 'double crush syndrome'.

A total of 122 patients were performed motor and sensory nerve conduction studies of the upper limb by two examiners (1. doctor, 2. medical technician) to know the inter-examiner reliability of nerve conduction measurements. Subjects contained normal individuals and various types of neuropathy patients. Motor nerve conduction studies were carried out in the median nerve, and antidromic sensory nerve conduction studies were performed in the median and ulnar nerves. F-wave latency of the median nerve and sensory conduction velocity between finger and wrist of the median and ulnar nerves presented the equal mean value between two examiners. A relatively good correlation between two examiners was pointed out in the distal motor latency and F-wave latency. Inappropriate measurements were caused by the differences in the site of placement of stimulating or recording electrodes and effects of submaximum stimuli or stimulus spread to other nerves. In sensory nerve conduction studies, especially in the ulnar nerve, careful attention should be paid to avoid the influence of motor artifact in giving supramaximum stimuli. Amplitude measurements showed larger inter-examiner difference than latency or velocity measurements. We reported the present condition of measurement reliability. We should do our best to minimize the error.

Acute sensory neuropathy (ASN) is characterized by rapidly progressive sensory ataxia and areflexia without motor weakness. The disease has been thought to be due to dorsal root ganglionitis which leads to secondary sensory nerve axonal degeneration. In contrast, we here report a patient with ASN, in whom results of nerve conduction study pointed to a direct involvement of the sensory nerve axons. A 33-year-old man was admitted to our hospital because of a few days history of progressive numbness in his extremities and unsteadiness of gait. The results of motor nerve conduction studies were normal. Amplitudes of sensory nerve action potentials (SNAPs) decreased within a few days after admission, whereas sensory nerve conduction velocities were preserved. Cerebrospinal fluid examination showed an elevated protein level without pleocytosis. He was diagnosed as having ASN, and was treated with four times of plasma exchange which rapidly restored SNAP amplitudes to normal. However, a few days after the plasma exchanges, SNAP amplitudes decreased again. Second series of plasma exchanges one month after admission transiently increased SNAP amplitudes again but not to normal range. These electrophysiologic changes were not associated with clinical improvement. A sural nerve biopsy one month after admission revealed axonal degeneration. These findings suggest that our patient's sensory impairment is caused by reversible sensory axonopathy due to humoral factors that can be removed by plasma exchange, as well as acute irreversible ganglionopathy which may lead to secondary axonal degeneration as shown by sural nerve biopsy.

In order to clarify the relationship among amplitudes of compound nerve action potential (CNAP), compound muscle action potential (CMAP) and nerve conduction velocity parameters, data of nerve conduction studies were analyzed in 102 patients with diabetes mellitus. In motor conduction studies CMAP amplitudes after stimulations at the distal nerve trunk, and the polyneuropathy index (PNI), a mean percentage of normal for 12 indices from 4 nerves concerning to the velocity or long distance latency, were evaluated. CNAP was recorded in the median and ulnar nerves from an intrafascicularly inserted microelectrode at the elbow after wrist stimulation. CMAP amplitudes were high in the median and ulnar nerves, and were reduced in the tibial and peroneal nerves. A close relationship was found between PNI and CNAP amplitudes. Among CMAP amplitude parameters tibial nerve, not median or ulnar nerves, had a good correlation with PNI and CNAP amplitude. Along with the progression of diabetic neuropathy, neuropathic signs or symptoms become conspicuous, and nerve conduction velocity drops as is expressed by the PNI level, which reflects the change in nerve conduction velocity in the upper and lower limbs. At the same time CNAP amplitude or CMAP amplitude in the tibial nerve decreases, but in nerves of the upper limb CMAP amplitude doesn't always decrease. So, tibial nerve is best among CMAP amplitude parameters in evaluating the degree of diabetic neuropathy. It is necessary to judge the degree of diabetic neuropathy after due consideration of these facts.

Repetitive nerve stimulation (RNS) test is recognized as being useful in the diagnosis of myasthenia gravis. We investigated incremental response at high rate stimulation. Healthy 20 median nerves were stimulated with 120% of supramaximal intensity. Compound muscle action potential (CMAP) was recorded with a surface electrode on the abductor pollicis brevis. In a single stimulus the amplitude of CMAP in the passive and voluntary flexion position of the thumb increased by 8% and 34% compared with that of the mid-position. Nevertheless, the negative potential areas (NPA) of CMAP slightly decreased by 2% and 5%, because of the briefer duration by 10% and 30%. Additionally, the size of the first 4 CMAPs in the non-fixed condition was compared with in the fixed by the examiner's hand in RNS test. With 10 and 20/sec stimulation, NPA decreased by 5% and 12% by the comparison of the fourth value with the first, though the amplitude increased by 9% and 24%. With 20/sec stimulation the fixed condition reduced the increase of amplitude by 24% to 18% and the decrease of NPA by 12% to 4%. Incremental response at high rate stimulation is a classical clinical finding, however, in our study NPA decreased while the amplitude increased, which may relate to the briefer duration. The appreciation of NPA will be desired to reduce the influence of synchronization. Moreover, muscle fiber was investigated in two conditions, shortened in passive flexion and fibrillated in voluntary flexion. Consequently, besides synchronization induced by fibrillation, the position change increasing the elasticity of muscle could play a role in the incremental response. The effect of fixation demonstrated this suggestion and movement of muscles must be minimized by every possible means in RNS test.

Sensory nerve action potentials (SNAPs) obtained by conventional sensory nerve conduction studies are greatly influenced by the distance between exploring and reference electrodes. Changes in SNAPs were investigated in 12 healthy median nerves using the orthodromic and antidromic sensory nerve conduction studies with 1-cm, 2-cm, 3-cm, 4-cm, and 5-cm of interelectrode distances. Peak-to-peak (orthodromic) or baseline-to-peak (antidromic) amplitudes and durations between the positive peaks were measured and each value was expressed as a ratio to the recording of 1-cm of interelectrode distance. SNAPs with maximum amplitude were obtained by more than 3-cm of interelectrode distance. Duration of SNAP was increased by an increase of interelectrode distance. Change in amplitude along with the interelectrode distance was larger in the orthodromic method than in the antidromic method. Contrariwise, change in duration was larger in the antidromic method. SNAPs with long duration had a gently sloping configuration, and each peak tended to be indistinct. So, 3-cm of active and reference interelectrode separation should be recommended in performing sensory nerve conduction studies between wrist and finger, because maximum amplitude and clear visualization of peaks are available.

Chronic inflammatory demyelinating polyneuropathy (CIDP) and hereditary motor sensory neuropathy type 1 (HMSN-1) are representative myelinopathies. In order to differentiate changes in acquired and congenital demyelinating neuropathies, we studied electrophysiologically 9 patients with active phase of CIDP (36.0 +/- 17.6 years old; mean +/- SD) and 7 patients with genetically-proven HMSN-1 A (56.0 +/- 13.6 years old). Motor conduction studies demonstrated longitudinal uniformity in HMSN-1, contrariwise focal conduction block or conduction delay in CIDP. The mean median nerve conduction velocity in the forearm segment and the mean CMAP amplitude stimulated at the wrist were not different between CIDP and HMSN-1 group; 31.8 +/- 7.2 m/sec and 5.6 +/- 2.8 mV in CIDP, and 26.7 +/- 9.8 m/sec and 3.2 +/- 2.6 mV in HMSN-1, respectively. Upper extremity polyneuropathy index (PNI), a mean percentage of normal for 6 indices concerning to the velocity and latency over two nerves obtained by motor conduction studies, was equal and around 50% on the average in each group. Conduction blocks were presented in 7 patients with CIDP and only one patient with HMSN-1. No sensory nerve action potential was recorded in 6 out of 9 patients with CIDP, and in 6 out of 7 patients with HMSN-1. Intrafascicular neurography of the median nerve, stimulated at the wrist and recorded from intrafascicularly inserted microelectrode at the elbow, revealed irregular multiphasic waves which signify severe temporal dispersion. Maximum conduction velocity was similarly reduced to 48 m/sec in CIDP and 44 m/sec in HMSN-1 on the average, but in one patient with HMSN-1 it was maintained to 63 m/sec with conspicuous temporal dispersion of the waveform. Amplitude of the compound nerve action potential (CNAP) decreased more (p0.01) in HMSN-1 (26 +/- 11 micro V) than in CIDP (72 +/- 25 micro V). Temporal dispersion of CNAP was prominent in HMSN-1 than in CIDP. In conclusion, electrophysiological changes were more homogeneous in the longitudinal distribution but more heterogeneous in the cross-sectional distribution in HMSN-1 than in CIDP.

In order to examine the specificity of the diagnostic criteria of CIDP, we studied 543 patients with diabetic neuropathy without clinical evidence of CIDP (307 men and 236 women, aged 60.4 +/- 11.1 years old). Moderate or severe neuropathy patients, whose polyneuropathy index (PNI) was below 80% of the normal, counted 169. Twenty out of 169 diabetic patients fulfilled the electrophysiologic criteria of CIDP. This number corresponded to more than 3.7% of the total diabetics. Motor conduction velocity category was fulfilled in 90%, conduction block in 65%, distal motor latency in 70% and F-wave latency category in 90% of 20 patients. Incomplete conduction block in the peroneal nerve and abnormally prolonged distal latency in the median nerve were frequent. These findings may reflect an overlaying focal compression. Decreased motor conduction velocity or prolonged F-wave latency were observed almost equally in every nerve. Electrophysiologic diagnostic criteria of CIDP was prepared to confirm the demyelinating nature of the neuropathy, and other demyelinating diseases should be ruled out. Diabetic patient who fulfilled this criteria was not rare. This fact is important, because clinical and CSF criteria of CIDP will be cleared in most of the diabetic patients; some diabetic neuropathy can be diagnosed as probable CIDP.

We investigated conventional motor and sensory nerve conduction studies (MCSSCS) with regard to the sensitivity in detecting axonopathies. Twelve patients with axonal type of polyneuropathy, 2 vincristin neuropathy and 10 cisplatin neuropathy, were examined by MCSSCS. Their data were compared with those by intrafascicular microneurography (MNG) of the median nerve. Nerve conduction velocities were within normal limits or slightly reduced to 87-99% of the normal. Amplitude of compound muscle action potential (CMAP) by MCS decreased to 4 or 5 mV in vincristin neuropathy, though cisplatin neuropathy presented normal amplitude. Amplitude of sensory nerve action potential (SNAP) by SCS was undetected in one median nerve and in three sural nerves. While, compound nerve action potential (CNAP) by MNG was all recorded, and presented the amplitude value of below 150 microV in seven patients. The waveform was normal or mild neuropathic pattern. No patients presented normal CNAP amplitude and reduced SNAP amplitude. But there were three patients who had normal SNAP amplitude and reduced CNAP amplitude. In SCS we could recognize abnormal only after CNAP amplitude by MNG dropped to below 100 microV. Cisplatin neuropathy demonstrates reduction of CNAP or SNAP amplitude, and vincristin neuropathy further presents reduction of CMAP amplitude. Evaluation of axonopathy is best achieved by nerve action potential amplitude. Conventional surface electrode methods are available for this purpose, but MNG is more sensitive and is capable of quantitative analysis even in severely damaged nerves.

We investigated 303 diabetic patients in order to clarify the relationship between progression of diabetic polyneuropathy and conduction delay across the carpal tunnel. Distal latency ratio (DLR) was determined by comparison of distal motor latency of the median nerve with that of the ulnar nerve. Lower extremity polyneuropathy index (LPNI), expressed as a mean percentage of the normal for six indices over two nerves obtained by motor nerve conduction studies, was 82.9% on the average in the patients. Their DLR (1.44 +/- 0.24) was larger than the normal value (1.29 +/- 0.10). About 30% of the diabetics had abnormal DLR, especially in women its incidence was as high as 39%. The lower the LPNI level, the larger the incidence of abnormal DLR. In diabetic polyneuropathy patients peripheral nerves will become fragile, which might increase the incidence of conduction delay across the carpal tunnel. This phenomenon might also be called as 'double crush syndrome'.

Nerve conduction blocks (NCBs) in Guillain-Barré syndrome (GBS) are frequently found at the distal terminals, proximal segments, and common entrapment sites of peripheral nerves. NCBs at distal terminals and proximal segments are considered to be due to vulnerability of the sites to the humoral factors of GBS because of relative blood-nerve barrier deficiencies. In contrast, it is not clear whether NCBs at common entrapment sites in GBS are due to a vulnerability to humoral influences or to direct mechanical compression injuries. We report a case of a 22-year-old man with GBS. His electrophysiologic examination revealed NCBs at multiple common entrapment sites. All conduction blocks rapidly disappeared after plasmapheresis, in parallel with clinical improvement. The patient was ambulatory throughout the clinical course, suggesting that his common entrapment sites remained free from compression injuries. Rapid improvement by plasmapheresis suggested that there were no demyelinative histologic changes in the NCB sites. Such NCBs may be caused by some humoral factor that is removed by plasmapheresis. Therefore, the common entrapment sites in our patient may have been especially vulnerable to the humoral factor of GBS.