Phosphorylation of Extracellular Signal-Regulated Kinase in medullary and upper cervical cord neurons following noxious tooth pulp stimulation

The phosphorylated Extracellular Signal-regulated Kinase (pERK) and Fos expression and masticatory muscle activity were analyzed in rats with capsaicin-induced acute inflammation of the tooth pulp in order to clarify the role of the spinal trigeminal nucleus and upper cervical spinal cord in tooth pulp pain. Digastric and masseteric muscle activities were significantly increased following capsaicin injection into the molar tooth pulp but not after vehicle treatment. The pERK-like immunoreactive (LI) neurons were observed in the subnuclei interpolaris-caudalis transition (Vi/Vc) zone, the paratrigeminal nucleus (Pa5) and the superficial laminae of the caudal Vc/C2 zone. The pERK expression was detected as early as 2 min and peaked at 5 min after capsaicin or vehicle injection. The pERK expression in the Vi/Vc zone and Pa5 was bilateral, whereas it was predominantly ipsilateral in the caudal Vc/C2 zone. The capsaicin treatment of the whisker pad produced pERK expression in the rostro-caudal middle portion of the ipsilateral Vc, but small number of pERK-LI cells were observed after vehicle treatment. The pERK expression was similar in the Vi/Vc zone following capsaicin injection into the upper or lower molar tooth pulp, whereas the pERK expression was in the lateral portion of the caudal Vc/C2 zone after upper molar injection and restricted to the medial portion of the Vc/C2 zone after the lower molar capsaicin. These data were confirmed with Western blots. There were differences in the distribution of Fos protein-like immunoreactive (LI) cells and pERK-LI cells following tooth pulp stimulation. After capsaicin application into the upper molar tooth pulp, no pERK-LI cells were observed in the ventral part of the Vi/Vc zone, whereas many Fos protein-LI cells were expressed in this region. The difference in the distribution pattern of pERK- and Fos protein-LI cells in the Vi/Vc zone suggests their differential temporal expression profiles after capsaicin. The present findings suggest that tooth-pulp-driven neurons in the spinal trigeminal nucleus are involved in tooth pulp pain through activation of the intracellular signal transduction pathway that involves earlier ERK phosphorylation and subsequent Fos expression.

Estimation of heritability for Tying-up syndrome in the Thoroughbred racehorse by Gibbs sampling

Tying-up is a condition that primarily affects the muscles of horses. In this study, the heritability of the Tying-up syndrome in the Thoroughbred racehorse was estimated by Bayesian analysis with Gibbs sampling based on the threshold model for binary traits. The data used were the clinical data in racehorses diagnosed by veterinarians of the Racehorse Clinics of Japan Racing Association from 2000 to 2003. The health status of the Tying-up was treated as a binary trait. In the genetic analysis, the effect of changing the amount of the pedigree or inbreeding information on the estimation of heritability was investigated, too. The heritability estimates with non-zero probability in the posterior densities were approximately 0.16-0.18 in minimum, suggesting that the heritability of the Tying-up is not zero at least. The posterior density distributions of the heritability estimates were generally more pointed and sharp with using inbreeding coefficients than without using it, suggesting that more stable estimations were obtained when inbreeding coefficients were used. Among the different amounts of pedigree and inbreeding information, the heritabilities obtained with three or four generations of pedigree using inbreeding coefficients seems to be preferable, i.e. heritability of 0.42 or 0.43 for Tying-up.

Crystallization and preliminary X-ray analysis of methionine aminopeptidase from the hyperthermophilic bacterium Pyrococcus furiosus

Methionine aminopeptidase (MAP) from Pyrococcus furiosus (Pfu) has been crystallized in four different forms (A, B, C and D). Form A crystals belong to space group P2(1) with unit-cell dimensions a = 54.18, b = 85.72, c = 72.84 A, beta = 108.34 degrees. Forms B, C and D belong to space group P6(2(4)) with unit-cell dimensions a = 139.1, c = 63.7 A for form B, a = 198.6, c = 243.8 A for form C, and a = 111.0, c = 125.0 A for form D. Forms A and D diffract to 2.9 A, form B diffracts to 3.5 A, and form C crystals diffract to 4.5 A. Form A contains two molecules of MAP-Pfu per asymmetric unit. The binuclear metal center positions and a non-crystallographic twofold symmetry matrix has been determined for the form A crystals.

Bone grafting in cementless total hip replacement for congenital dysplasia of the hip

We reviewed 27 cementless primary total hip replacements in patients with osteoarthrosis secondary to congenital dysplasia of the hip. Autogenous bone grafting was used as augmentation. On average the follow-up period was 9 years. Two hips were revised and three acetabular components were considered loose. In hips with loose cups the average graft coverage was significantly greater than in stable hips. The use of a cementless acetabular component is encouraging for reconstruction, although extensive grafting should be avoided. Our study suggests that cementless reconstruction in dysplastic hips yields a satisfactory outcome.

Serial measurement of polyethylene wear of well-fixed cementless metal-backed acetabular component in total hip arthroplasty: an over 10 year follow-up study

Serial radiographic measurements of polyethylene wear were performed in 38 hips (33 patients) with primary cementless total hip arthroplasty (THA). The average follow-up period was 131.8 months. All prostheses were assessed as radiographically stable at the latest follow-up. A two-dimensional method was used to calculate the relative migration of the femoral head center to the cup center. The average total linear wear and wear rate were 1.22 mm and 0.11 mm/year, respectively. The degree of wear in the first 2 postoperative years accounted for nearly 40% of the total wear at the end of the study (average follow up: 131.8 +/- 10.0 months, +/-SD). The migration of the femoral head at an average period of 3. 4 months after operation accounted for 56% of the amount of wear in the first 2 years. Wear rate decreased gradually with time and stabilized after the fourth year. However, in 2 patients, a progressive increase in the wear rate was associated with severe osteolysis and failure of THA. Both creep and wear contributed to the femoral penetration into the polyethylene liner. The influence of creep cannot be ruled out, especially in the early period after operation. Polyethylene wear is a multifactorial process, and the study of individual wear patterns might be useful in identifying patients who are at risk of late failure of THA.

Use of an instrument sandwiched between the hoof and shoe to measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter in horses

OBJECTIVE

To develop an instrument that could be sandwiched between the hoof and shoe of horses and that would reliably measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter.

ANIMALS

5 clinically sound Thoroughbreds.

PROCEDURES

The recording instrument (weight, 350 g) consisted of 2 metal plates, 2 bolts, 4 load cells, and 3 accelerometers. It was mounted to the hoof with a glue-on shoe and devised to support as much load exerted by a limb as possible. The load cells and accelerometers were wired to a 16-channel transmitter, and transmitted signals were received and amplified with a telemetry receiver.

RESULTS

The recording instrument could measure in real time the 4 components of the ground reaction force or their resultant force along with acceleration in 3 dimensions as horses walked, trotted, or cantered on a treadmill. Patterns of force-time curves recorded for consecutive strides were similar to each other and to those previously reported, using a force plate.

CONCLUSIONS AND CLINICAL RELEVANCE

The recording instrument developed for use in the present study allowed us to record vertical ground reaction force and acceleration in 3 dimensions in horses at the walk, trot, and canter.

Influence of rough track surfaces on components of vertical forces in cantering thoroughbred horses

No kinetic data are available to indicate the influence of a rough track surface and the resultant loss of footing on the components of hoof vertical forces. The aim of the present study was to evaluate the influence of rough track surfaces on the components of hoof vertical forces. Seven clinically sound 2-year-old Thoroughbred horses had instrumented shoes attached to both of the fore hooves to obtain the magnitudes of consecutive forces exerted in the hoof. All horses were cantered at approximately 10 m/s on straight tracks of smooth and rough surfaces of woodchip and dirt. The instrumented shoe indicated in real time 4 component forces acting on the hoof via 4 transducers positioned on the lateral and medial sides of the toe (LT, MT) and the heel (LH, MH). The peak vertical component forces of the heel were about twice that of the toe. The variances of the 4 components of peak vertical forces significantly increased on the rough track surface of both the woodchip (Leading: LH, MH and MT; Trailing: MH and LT) and dirt (Leading: LH and LT; Trailing: MH and MT) tracks. The trajectories of the position of the resultant force acting on the hoof also tended to increase the variance on rough track surfaces. Therefore, running on a rough track changes the vertical hoof forces and the balance of the resultant hoof forces. These results suggest a mechanism by which the rough track surfaces may influence the soundness of the horse.

EMG activity of the muscles of the neck and forelimbs during different forms of locomotion

We recorded the electromyographic (EMG) activity of 7 skeletal muscles in the forequarters and 1 in the hindquarters of 6 Thoroughbred horses during overground walking, swimming in a circular pool, and walking and trotting in a water treadmill. Bipolar fine wire electrodes were inserted into the muscles and the EMG signals were recorded using a telemetric system. The splenius exhibited tonic EMG activity during swimming. The brachiocephalicus showed its highest intensity during swimming followed by the walk and trot in the water treadmill and then walking overground. The triceps brachii caput longum had a similar activity pattern to the brachiocephalicus. The brachialis showed only weak EMG activity in all 3 types of locomotion. The extensor digitorum communis had higher intensity of EMG activity in the walk in the water treadmill than in other kinds of locomotion. The flexor digitorum profundus exhibited the most intense EMG activity during swimming. These results indicated that swimming evoked strong EMG activity in the antigravity muscles in spite of reduced gravitational force. Walking in the water treadmill may require more intensified EMG activity of the forelimb than the trot in the same treadmill.

Refined structure of orthorhombic lysozyme crystallized at high temperature: correlation between morphology and intermolecular contacts

The structure of orthorhombic hen egg-white lysozyme (HEWL) crystallized at 310 K has been refined at 1.7 A resolution. Large displacements of the side-chain atoms with respect to the tetragonal structure were observed in many places, in contrast to small displacements of the main-chain atoms. A chloride-ion binding site was observed at an interface of two molecules, but at a different position to the binding site in the tetragonal form. The analysis of intermolecular contacts in the crystal has shown the presence of three independent intermolecular contacts which are called macrobonds A, B and C. Arginine side chains are frequently involved in these macrobonds, suggesting that the high frequency of this residue in HEWL may be a possible reason for the multiple polymorphs of this protein. The crystal forms were determined using a light-reflecting device on a four-circle diffractometer. Correlations between crystal forms and the three-dimensional macrobond networks were interpreted in terms of their components in various crystallographic planes, making use of approximate strengths of hydrogen-bond and van der Waals interatomic forces.

Crystal structure of methionine aminopeptidase from hyperthermophile, Pyrococcus furiosus

The structure of methionine aminopeptidase from hyperthermophile Pyrococcus furiosus (PfMAP) with an optimal growth temperature of 100 degreesC was determined by the multiple isomorphous replacement method and refined in three different crystal forms, one monoclinic and two hexagonal, at resolutions of 2.8, 2.9, and 3.5 A. The resolution of the monoclinic crystal form was extended to 1.75 A by water-mediated transformation to a low-humidity form, and the obtained diffraction data used for high-resolution structure refinement. This is the first description of a eukaryotic type methionine aminopeptidase structure. The PfMAP molecule is composed of two domains, a catalytic domain and an insertion domain, connected via two antiparallel beta-strands. The catalytic domain, which possesses an internal 2-fold symmetry and contains two cobalt ions in the active site, resembles the structure of a prokaryotic type MAP from Escherichia coli (EcMAP), while the structure of the insertion domain containing three helices has a novel fold and accounts for a major difference between the eukaryotic and prokaryotic types of methionine aminopeptidase. Analysis of the PfMAP structure in comparison with EcMAP and other mesophile proteins reveals several factors which may contribute to the hyperthermostability of PfMAP: (1) a significantly high number of hydrogen bonds and ion-pairs between side-chains of oppositely charged residues involved in the stabilization of helices; (2) an increased number of hydrogen bonds between the positively charged side-chain and neutral oxygen; (3) a larger number of buried water molecules involved in crosslinking the backbone atoms of sequentially separate segments; (4) stabilization of two antiparallel beta-strands connecting the two domains of the molecule by proline residues; (5) shortening of N and C-terminal tails and stabilization of the loop c3E by deletion of three residues.

High-resolution crystals of methionine aminopeptidase from Pyrococcus furiosus obtained by water-mediated transformation

The monoclinic crystal form of methionine amino-peptidase from Pyrococcus furiosus (MAP-Pfu) has been crystallized from four different conditions. Native crystals belong to space group P2(1) with typical unit-cell dimensions a = 53.4, b = 85.1, c = 72.7 A, beta = 107.7 degrees and diffract to 2.9-4.5 A resolution. However, there is a problem of nonisomorphism among the crystals. Water-mediated transformation to low-humidity form occurs by reduction of the relative humidity of crystal environment to 79%. The unit-cell dimensions of transformed crystals are a = 51.9, b = 83.3, c = 70.3 A, beta = 105.9 degrees, and the calculated solvent content is 3.9% less than in original crystals. Transformation to low-humidity form is accompanied by 1.7 times reduction of overall temperature factors, extension of diffraction resolution up to 1.75 A, without change or reduction of crystal mosaicity, and improvement in stability to X-ray radiation. The water-mediated transformation also appears to relieve the problem of nonisomorphism among the original MAP-Pfu crystals.

Pituitary stalk meningioma: case report

We report a 45-year-old woman with a meningioma which was in contact with only the pituitary stalk on MRI. As the pituitary stalk has no dura mater, we suggest this tumour may have originated from the arachnoid membrane of the pituitary stalk. Though some reports have shown that meningiomas can arise from sites lacking a dural component, this is the first report of a meningioma originating from the pituitary stalk.

Assessment of autonomic nervous function by power spectral analysis of heart rate variability in the horse

We studied power spectral analysis of heart rate (HR) variability in the horse, with the hypothesis that the quantitative information provided by the spectral analysis of HR variability reflects the interaction between sympathetic and parasympathetic regulatory activities. For this purpose, electrocardiogram, blood pressure (BP) and respiratory (Resp) waveform were simultaneously recorded from Thoroughbred horses (3-5 years old) and analyzed by power spectrum. There were two major spectral components at low-frequency (LF) and high-frequency (HF) bands for HR variability. The peak of Resp variability clearly occurred at the HF range. In contrast to Resp variability, the power spectra of BP variability occurred at lower frequencies. The maximum coherence between HR and Resp variabilities and HR and BP variabilities occurred at approximately 0.15 and approximately 0.03 Hz, respectively. These relationships were similar to the ensemble spectra. On the basis of these data, we have defined two frequency bands of interest: LF (0.01-0.07 Hz) and HF (0.07-0.6 Hz). Therefore, we believe that power spectral analysis of HR variability provides a very powerful technique for assessing autonomic nervous activity in the horse.

Benign convulsions with mild gastroenteritis: a report of 10 recent cases detailing clinical varieties

To better define the characteristic clinical features of benign convulsions with mild gastroenteritis, recently recognized as a new entity in Japan, we reviewed all the 10 patients we have seen from 1992 to 1994. The clinical features have been previously reported in the literature to be afebrile generalized tonic-clonic seizures occurring between the first and the fifth sick day of mild gastroenteritis. In our series, four of 10 patients had convulsions before the onset of gastroenteritis. Overall, seizures were mostly brief and often repetitive occurring in cluster (19 seizures/10 episodes). Among these, a prolonged or partial seizure was frequently observed. In six of the 10 patients, the seizure type changed during an episode: from generalized to partial seizures (n = 2), from partial to generalized seizures (n = 2), or from partial to another type of partial seizures (n = 2). None in our series experienced a recurrence episode of afebrile convulsion during follow-up. These findings suggest that benign convulsions with mild gastroenteritis exhibit some variations in their clinical manifestation.

Cardiac sympathetic innervation in patients with dilated cardiomyopathy--immunohistochemical study using anti-tyrosine hydroxylase antibody

Depletion of norepinephrine in the left ventricular myocardium in cases of dilated cardiomyopathy (DCM) has been suggested. However, there have been few histological studies of the sympathetic nerves, in which myocardial norepinephrine is believed to exist. We performed an immunohistological study of the density of tyrosine hydroxylase (TH, a marker of sympathetic nerves)-positive nerve fiber in endomyocardial biopsy specimens in cases of DCM using antibody against TH. TH-positive nerves were stained brown along with the myocardium, and they were more dense in the right ventricle than in the left ventricle in both the DCM and control groups. The density of TH-positive nerves in cases of DCM was significantly less than that in the control group in the subendocardial myocardium of the right and left ventricles, but especially in the left ventricle. A correlation was observed in the DCM group between the density of TH-positive nerves and the ejection fraction in the right ventricle, but not in the left ventricle. In the failing human heart, a decrease in subendocardial sympathetic nerve density may be one of the causes of myocardial norepinephrine depletion.

[The study of continuous local arterial-infusion chemotherapy with 5-FU + CDDP for patients with severely advanced HCC--for the elongation of the life-span and the improvement of QOL]

We tried continuous local arterial-infusion chemotherapy using 5-FU + CDDP with an implanted reservoir, for patients with severely advanced hepatocellular carcinoma (HCC), who had no indications for operation, PEIT or TAE. Arterial-infusion was continued for one week, followed by a one-week no-infusion period, and this treatment was repeated 1-32 times, and patients were observed for 36-549 days. Until the end of April 1993, the one-year survival rate was 61.1%. There were 3 partial remission (PR) cases, 3 progressive disease (PD) cases and the other cases showed no change (NC). Only one patient had any side effects, and all could continue as outpatients for 94.0% of the entire therapy. The patients' evaluation of QOL revealed no differences of QOL according to the length of the whole therapy, the history of rehospitalization during therapy, response to therapy, etc. But PR cases tended to show improved QOL. Therefore we considered this as effective therapy for the elongation of the life-span and the improvement of QOL.

Sequence in DNA synthetic phase ratio of spontaneous hypertensive rat (SHR) myocardium--study on development of cardiomegaly

We studied the relative synthetic phase (S-phase) ratio of cardiac myocytes of spontaneously hypertensive rats (SHR) utilizing monoclonal antibody to 5-bromo 2'-deoxyuridine (BrdU), a halogen derivative of thymidine. BrdU was administered intraperitoneally to SHR and Wistar Kyoto rats at 66.7 mg/kg/day for 3 consecutive days. The rats were sacrificed 1 week after the first injection of BrdU. Using anti-BrdU antibody, myocardial tissue was stained by the avidin biotinylated peroxidase complex method. We assessed the ability of the nuclei to synthesize DNA. The percentage of BrdU-labeled myocytes was higher in SHR than in control rats at 9 weeks. The hyperplastic phase of heart growth in rats was presumed to occur about 3 weeks after birth. From these results, the ability of the myocardial cell to synthesize DNA is probably enhanced under the load of high blood pressure in the early hypertrophic phase following hyperplasia.

Phosphorus-31 NMR spectra by the linear prediction z-transform method

The linear prediction z-transform method (LPZAR) was applied to estimate 31P NMR spectra of perfused rat hearts. The spectra obtained by the LPZAR method showed sharper peaks with less noise for phosphate concentrations than those obtained by conventional fast Fourier transform. The LPZAR method provided a better estimation of intracellular phosphate concentrations in short acquisition time experiments in which condition Fourier transform spectra are not suitable for the quantification due to the poor resolution of FFT spectra. Utilizing the LPZAR method, rapid changes in phosphoric metabolites of the heart can be monitored during ischemia followed by reperfusion.

Artificial neural networks for source localization in the human brain

Source localization in the brain remains an ill-posed problem unless further constraints about the type of sources and the head model are imposed. Human head is modeled in various ways depending critically on the computing power available and/or the required level of accuracy. Sophisticated and truly representative models may yield more accurate results in general, but at the cost of prohibitively long computer times and huge memory requirements. In conventional source localization techniques, solution source parameters are taken as those which minimize an index of performance, defined relative to the model-generated and clinically measured voltages. We propose the use of a neural network in the place of commonly employed minimization algorithms such as the Simplex Method and the Marquardt algorithm, which are iterative and time consuming. With the aid of the error-backpropagation technique, a neural network is trained to compute source parameters, starting from a voltage set measured on the scalp. Here we describe the methods of training the neural network and investigate its localization accuracy. Based on the results of extensive studies, we conclude that neural networks are highly feasible as source localizers. A trained neural network's independence of localization speed from the head model, and the rapid localization ability, makes it possible to employ the most complex head model with the ease of the simplest model. No initial parameters need to be guessed in order to start the calculation, implying a possible automation of the entire localization process. One may train the network on experimental data, if available, thereby possibly doing away with head models.

Repetitive intratumoral hemorrhage in medulloblastoma. A case report

An 8-year-old girl experienced five repeated hemorrhagic episodes around the cerebellar vermis. Surgical specimens histologically showed abnormal vascular components invaded by tumor cells. Autopsy disclosed medulloblastoma disseminating in the subependymal zone of the ventricles. An atypical clinical course is reported with special attention to the cause of hemorrhage.

Analysis of premovement components of movement-related cortical potentials in patients with Parkinson's disease or brain tumors

We have recorded movement-related cortical potentials (MRCPs) preceding voluntary finger extension in patients with Parkinson's disease and in patients with brain tumors that may involve the motor system. Three components of potential shifts preceding the voluntary movement were identified in all subjects. There were no differences between the healthy subjects and those with Parkinson's disease, or between pre- and postoperative recordings from the same parkinsonian patients in terms of onset latencies and gradients of these potential shifts. There was no evidence of MRCPs from the depth electroencephalogram recorded from the thalamic ventrolateral (VL) nucleus. After removal of the cerebellar dentate nucleus along with a tumor, MRCPs were still identified. After removal of tumors from the supplementary motor cortex and frontal association cortex, a part of the MRCPs preceding the voluntary movement was absent. The generation of MRCPs was considered not to be greatly affected by the cerebellar system because: (1) no MRCPs were detected from the thalamic VL nucleus, which is the relay nucleus of the dentato-rubro-thalamic pathway, believed to be related to voluntary movement; (2) destruction of the VL nucleus did not cause any changes in the MRCPs recorded at other sites, and (3) the MRCPs did not disappear when the dentate nucleus, an output system, was excised.

[MRI findings of locked-in syndrome--a case report]

We report a case of Locked-in syndrome caused by thrombus in basilar artery resulting in a brainstem infarction in the ventral pons, magnetic resonance imaging (MRI) shows abnormal signal intensity regions in the ventral pons and basilar artery clearly.