Acute disseminated encephalomyelitis confined to brainstem.

A 21-year-old man was troubled with a subacute history of brainstem involvement and a leukocyte pleocytosis in the cerebrospinal fluid. Magnetic resonance imaging (MRI) demonstrated a massive lesion with Gd enhancement in the pons. Steroid therapy, not antiviral drugs, was dramatically effective for the mass reduction and symptom improvement. Over 4 years no recurrence has been recognized, so this case was diagnosed to be an unusual case of acute disseminated encephalomyelitis (ADEM). ADEM must be included in the differential diagnosis for a brainstem mass in MRI.

Observation of charge state and conformational change in immobilized protein using surface plasmon resonance sensor.

Behaviors of proteins immobilized on a solid surface were investigated using BIACORE, a biosensor utilizing surface plasmon resonance. This sensor is usually used for analyzing binding events during biomolecular interactions. Here we propose a novel use of this sensor to monitor two kinds of intramolecular changes in immobilized proteins. Several proteins were covalently attached to dextran chains on the sensor surface in the flow cell and were then exposed to a series of buffers with varying pH. Signal changes derived from changes of refractive index around the sensor surface were detected during and after the exposure to each of these buffers, which we denoted as in situ values and postvalues, respectively. The in situ value reflects the behavior of immobilized proteins in these buffers and was revealed to have a correlation with total charge state of the proteins, while the postvalue reflects how immobilized proteins react after the exposure and was suggested to represent the degree of conformational changes of the proteins. This method is expected to be applicable to various analyses and can provide us with new information about the behavior of proteins on solid phase.

Pure alexia from a posterior occipital lesion.

The authors report a patient with pure alexia (letter-by-letter reading) selectively impaired for kana (Japanese phonograms), cerebral achromatopsia, and right lower quadrantanopsia after hemorrhage in the left posterior occipital lobe, mainly under the lateral occipital gyri. The patient also could not recognize some single-character kana, nor could he discriminate between two shapes of a similar size. The authors believe that the posterior occipital lobe, including the lateral occipital gyri, is specialized to recognize kana characters in this patient.

Monitoring of the refolding process for immobilized firefly luciferase with a biosensor based on surface plasmon resonance.

In order to examine the possibility of the use of a surface plasmon resonance (SPR) sensor for real-time monitoring of the process of refolding of immobilized proteins, the refolding of firefly luciferase immobilized on a carboxymethyldextran matrix layer was analyzed. The SPR signal of the immobilized luciferase decreased after unfolding induced by GdnCl and increased gradually in the refolding buffer, while there was no signal change in the reference surface lacking the immobilized protein. The decrease in the SPR signal on unfolding was consistent with the difference between the refractive indices of the native and unfolded protein solutions. The effects of blocking of the excess NHS-groups of the matrix layer on the refolding yield were examined by means of an SPR sensor. The results were consistent with those obtained with the enzymatic activity assay, indicating that the changes in the SPR signal reflected the real-time conformational changes of the immobilized protein. Hence, an SPR biosensor might be used for monitoring of the process of refolding of immobilized proteins and as a novel tool for optimization of the refolding conditions. This is the first demonstration that SPR signal changes reflect the conformational changes of an immobilized protein upon unfolding and refolding.

Expanded-bed protein refolding using a solid-phase artificial chaperone.

An efficient solid-phase protein refolding method based on artificial chaperone-assisted refolding is proposed. The method employs insoluble cyclodextrin polymer beads and the expanded-bed technique. Alpha-glucosidase, whose spontaneous refolding yield from a urea-denatured state is up to 30% at a protein concentration of up to 10 microg/ml, could be refolded with a yield that was improved more than two-fold at a protein concentration more than five-fold higher when protein solution was circulated through an expanded bed under optimized conditions. Unlike the conventional liquid-phase artificial system, further steps to purify the refolded product, which are generally needed to remove detergent-cyclodextrin complex and excess cyclodextrin, were unnecessary. In addition, the polymer beads were reusable after simple washing with water, and the continuous system is suitable for easy-scale-up using commercially available devices. This new method is considered to be a powerful means of achieving large-scale protein refolding for industrial protein production.

Neuropathological findings of Onuf's nucleus and its significance.

Onuf's nucleus is a small group of cells which are located mainly in the anterior horn of the second sacral segment of the spinal cord. This paper describes the history of studies relating to this nucleus including a discussion of its relation with the various pathological studies which have been made.

Rapidly progressive polymyositis with elevated antiacetylcholine receptor antibody activity.

We report a 51-year-old woman with polymyositis accompanied by a high titer of antiacetylcholine receptor antibody. The patient presented with weakness of grip strength followed by rapidly progressive dyspnea, which required mechanical ventilation. She was treated with a glucocorticoid and came off the respirator one week later. Antiacetylcholine receptor antibody activity was elevated in the acute phase and decreased during recovery, although other signs of myasthenia gravis were negative. This patient suggested that in cases of rapidly progressive bulbar palsy and limb muscle weakness, it is necessary to include polymyositis associated with elevated antiacetylcholine receptor antibody activity in the differential diagnosis.

Direct refolding of recombinant human growth differentiation factor 5 for large-scale production process.

An efficient downstream process for the production of recombinant human growth differentiation factor 5 (rhGDF5) has been developed for industrial application utilizing a novel "direct refolding" method. In this method, the starting material is an inclusion body produced in Escherichia coli, and the critical step is the direct refolding step that follows directly after solubilization of the inclusion body. rhGDF5 can be refolded at a markedly high concentration of 2.4 mg.ml(-1), which is 24 times that hitherto achieved by the proteins of the TGF-beta superfamily. The refolding yield is 63%, and after purification by diafiltration, isoelectric precipitation and reverse-phase chromatography, the final purification yield is 20% with purity higher than 99%. The yield is more than twice that of a conventionally established process having three chromatography steps and the purity is equivalent. The first pilot-scale trial shows a refolding yield of 51% and a final yield of 11%. The final yield is 1.4 times that of the conventional process, and further optimization at pilot-scale is expected to bring this figure up to or above that of laboratory-scale. As a result, the calculated production cost of rhGDF5 has been reduced dramatically. This type of efficient and simple process is beneficial particularly in the large-scale production of recombinant proteins in which high yield and quality are required.

[The clinical usefulness of high-dose intravenous immunoglobulin therapy for chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy].

To explore the optimum dose of intravenous immunoglobulin (i.v.Ig) for treating patients with chronic inflammatory demyelinating polyrneuropathy and multifocal motor neuropathy, we compared the usefulness of i.v.Ig among 3 treatment doses. Fifty-nine patients were randomly divided into three treatment dosage groups: 20 patients for Group I using 50 mg/kg/day x 5 days, 19 patients Group II using 200 mg/kg/day x 5 days, and 20 patients Group III using 400 mg/kg/day x 5 days. We assessed clinically and electrophysiologically the effectiveness of the treatment at 5 weeks after the initial infusion. For patients in Group I and II who had not improved (or worsened) with the first treatment, we gave a one-step larger dose in the second treatment (i.e. 200 mg/kg/day x 5 days for those who had been given 50 mg/kg/day x 5 days, 400 mg/kg/day x 5 days for those who had been given 200 mg/kg/day x 5 days) after more than 9 weeks. We found that 15% of the patients in Group I, 21% in Group II and 60% in Group III improved dose-dependently with the first intravenous immunoglobulin treatment. Seven (47%) of 16 patients in Group I and 4 (40%) of 11 patients in Group II improved after the second treatment with larger doses. Adverse reactions including chill sensation, fever, skin eruption and increase in blood GOT and GPT levels were transient and mild. One patient in Group III developed left hemiparesis showing the small infarction in the right thalamus during the course of the treatment, but the symptom was mild. In conclusion, the high-dose intravenous immunoglobulin therapy (400 mg/kg/day x 5 days) is useful for treating patients with CIDP and MMN, although care must be taken of the risk of causing cerebral infarctions.

Detailed analysis of the latencies of median nerve somatosensory evoked potential components, 2: Analysis of subcomponents of the P13/14 and N20 potentials.

Detailed analysis of P13/14 and N20 wavelets was performed for 62 normal subjects and patients with various lesions along the somatosensory pathway. A histogram of the latencies of all the identified P13/14 wavelets (measured from P13/14 onset) demonstrated three latency-groups, which were named P13, P14a and P14b subcomponents. The relationship between the three newly identified subcomponents and the conventional naming of P13 and P14 was inconstant, indicating the ambiguity of the latter. P14b was most prominent in the contralateral central region, and therefore a P15 positivity slightly after P14b was often recorded in the CPc-Fz and CPc-CPi leads (CPc and CPi are centroparietal electrodes contralateral and ipsilateral to the stimulation). P14b/P15 was lost even in patients with cortical lesions, and thalamocortical fibers were assumed for its origin. The CPc-Fz and CPi-Fz leads registered a low negativity named broad N13', suggesting frontal predominance of the overall P13/14 complex. Both P13 and P14a were identified in a patient with a pontine lesion, and a caudal brainstem origin for both was suspected due to the onset of two repetitive bursts of the ascending lemniscal volley. We refuted the presynaptic origin of the scalp P13 potential and pointed out that a prolonged and/or polyphasic P11 frequently observed in patients with high cervical lesions can be mistaken as scalp P13. A histogram of the latencies of all the identified negative wavelets of N20 in the CPc-Fz lead (measured from N20 onset) revealed five definite latency-groups, which were named N20a, N20b, N20c, N20d and N20e subcomponents. The highest peak of N20 actually corresponded to either N20b, N20c or N20d, and this uncertainty, which must be related to intracortical processes, resulted in a large instability of the N20 peak latency as well as the age and sex dependence of the N20 onset-peak interval, both of which were demonstrated by our preceding study (Sonoo, M., Kobayashi, M., Genba-Shimizu, K., Mannen, T. and Shimizu, T. Detailed analysis of the latencies of median nerve SEP components, 1: selection of the best standard parameters and the establishment of the normal values. Electroenceph. clin. Neurophysiol., 1996b, 100: 319-331). Negative subcomponents in the CPc-NC lead and positive subcomponents in the Fz-NC lead constituted mirror images of each other, which suggested that these subcomponents were generated within area 3b.

Detailed analysis of the latencies of median nerve somatosensory evoked potential components, 1: selection of the best standard parameters and the establishment of normal values.

In order to objectively select the standard parameters best suited for the evaluation of somatosensory conduction in median nerve somatosensory evoked potentials (SEP), we performed a detailed statistical analysis of intersubject variability for the latencies of SEP components based on the recordings of 62 normal subjects. Multiple regression analyses for height, age, (age--20)2 and sex were performed for the latencies of 13 components and 78 intercomponent intervals, and the residual variance was used as an indicator of the stability of each parameter. As a result, N9 onset in EPi-NC lead, N11' onset in C6S-Fz lead, P13/14 onset in scalp-NC leads, for which N13' onset recorded in C6S-Fz lead may substitute, and N20 onset in CPc-Fz lead were the most stable time-points selected as standards. N11 onset in C6S-NC, which other authors have recommended as the standard point representing spinal entry, was not recorded consistently, and P11 onset in scalp-NC leads was also unstable. N20 peak and N13'-N20 interval (equivalent to conventional central conduction time) were extremely unstable. We presented the nomograms to find normal limits of the standard parameters corresponding to the given values of the predictor variables (height, age or sex). As the standard recording montage in routine clinical examinations, we recommended a simple method using Fz reference, for example (1) EPi-Fz, (2) C6S-Fz, (3) CPc-Fz, because this montage is sufficient to measure the stable standard parameters.

Cortical dysgenesis in a patient with Turner mosaicism.

In a patient with Turner mosaicism who had mental retardation, epilepsy and cerebellar ataxia, MRI showed cerebellar atrophy and a bizarre cortical dysgenesis of the cerebrum, which was considered to comprise a mixture of relatively normal gyri and structures resembling pachygyria and lissencephaly. The karyotype of the patient was 45,X/47,XXX, but the brain dysgenesis could not be explained solely on the basis of this mosaicism, which is rarely associated with a gross abnormality in brain pathology. Abnormality of the X chromosome seems to have some potential for inducing cortical dysgenesis, and this case may be partially attributable to an abnormal locus on the X chromosome.

Some unusual responses of astrocytes to ghost tangles in a long duration case of juvenile Alzheimer's disease: an electron microscopic study.

The ghost tangles (GTs) in usual Alzheimer's disease are separated into small bundles of abnormal straight filaments by many invading astrocytic processes lacking a basal lamina (BL). An electron microscopic study of GTs in the Ammon's horn of a case of juvenile Alzheimer's disease of 25 years' duration, however, revealed that only a small number of astrocytic processes had infiltrated the GTs, resulting in the GTs being composed of large bundles. Moreover, the majority of glial processes that had invaded or apposed GTs possessed an interrupted but still fairly well-developed BL with hemidesmosome-like profiles. Although pia-arachnoid cells are required for astrocytes to form a continuous BL, astrocytes can have a segmental BL on their surface facing even empty intercellular spaces within the brain parenchyma. The much greater frequency and better development of the GT-associated BL in our case indicate that the GT filaments somehow increased the ability of astrocytes to form a BL. On the other hand, the scarcity of GT-invading astrocytic processes implies that many of the glial processes that had once penetrated GTs had been withdrawn, with the result that GTs escaped expectable endocyto-phagocytosis by astrocytes.

[Dose-response relationship in the treatment of cervical dystonia with botulinum toxin type A (AGN 191622)--a phase II study].

Injection of botulinum toxin type A has been the treatment of choice for spasmodic torticollis for several years. Although previous reports demonstrate its effectiveness and safety, the treatment strategy has been empirical. The present study, using the freeze-dried crystalline botulinum toxin type A (AGN 191622; Allergan Inc., Irvine, CA), aimed to compare the efficacy among three treatment groups divided into low, medium and high dosage levels. Fifty-one patients who entered the study were grouped into low-dose (60 units/session), medium-dose (120 units/session) and high-dose (240 units/session) groups. Two patients (one in low-dose group and the other in high-dose group) were excluded from the assessment of efficacy because they dropped out in the early phase of the study. One experienced worsening of an existing psychosis and the other developed an acute respiratory infection. Injection sites were decided individually by palpation. If the clinical response was not satisfactory four weeks after an injection, the patient was re-injected with the same dose of toxin. The follow-up period was 14 weeks from the initial injection. The results showed that the high-dose group improved more than the other groups in the parameters of severity of symptoms and subjective benefit (p = 0.000). Also, fewer injections were required in the high-dose group to achieve substantial clinical benefit. Although the mean reduction in Tsui's score was not statistically significant among the groups, the "marked improvement" was seen more frequently in the high-dose group (p = 0.033). Unfavorable adverse effects including excessive weakness and dysphasia were always mild and transient.(ABSTRACT TRUNCATED AT 250 WORDS)

Three-dimensional MR imaging of brain surface anomalies in Fukuyama-type congenital muscular dystrophy.

Fukuyama-type congenital muscular dystrophy (FCMD), the second most common childhood muscular dystrophy in Japan, is characterized by the association with severe brain anomalies such as pachygyria and focal interhemispheric fusion. Conventional imaging techniques such as X-ray CT scan and MRI are ineffective for visualization of these brain surface anomalies. Here we investigated the efficacy of three-dimensional (3-D) reconstruction of brain surface MR images for the detection of brain anomalies in FCMD patients. 3-D brain surface MR images clearly visualized anomalies of cerebral gyrus such as pachygyria, as well as focal interhemispheric fusion. In addition, reconstructed horizontal images visualized structural derangement such as abnormal protrusion of white matter into gray matter. MR image abnormalities were confirmed by autopsy in 1 patient. These abnormalities were never observed in Duchenne muscular dystrophy (DMD) patients. Our results indicate the efficacy of the present method for the differential diagnosis between FCMD and DMD with severe mental retardation, which is essential for the genetic study to identify the causative gene of FCMD.

[MRI of anterior spinal artery syndrome--chronological study].

We reported two cases of anterior spinal artery syndrome serially observed by MRI of the spinal cord. On the 8th and 10th days respectively, MRI with Gd revealed high signal intensity areas which were thought to be located in the anterior horn region of the two patients. On the 28th and 37th days respectively, there was no enhancement on the MRI with Gd. This enhancement in the anterior horn region might be correlated with vulnerability of the anterior horn to ischemia, and capillary proliferation due to simultaneous appearance of this enhancement with that of capillary proliferation after liquidization of the anterior horn. Therefore, the enhancement on the MRI indicates a correspondence with pathological findings and is be characteristic of anterior spinal artery syndrome.

Infarction of the unilateral posterior horn and lateral column of the spinal cord with sparing of posterior columns: demonstration by MRI.

Infarction of the spinal cord, particularly in the distribution of the posterior spinal arteries, is rare. Twenty seven cases of posterior spinal artery syndrome have been reported. In all cases, the posterior columns were affected, and in all but two, the lesions were bilateral. Here a 49-year-old woman is reported, who was affected with lumbar cord infarction in the distribution of the posterior spinal arteries, diagnosed by MRI and clinical presentation. This case is of special interest because of sparing of the posterior columns and the unilateral nature of the lesion, even though the infarction occurred in the distribution of the posterior spinal arteries.