Human umbilical vein endothelial cells support interleukin-3- and interleukin-5-induced eosinophil differentiation from cord blood CD34+ cells

BACKGROUND

Human umbilical vein endothelial cells (HUVEC) are an important source of hematopoietic cytokines, and interleukin-3 (IL-3)- and IL-5-induced eosinophil differentiation from CD34+ cells has been observed. To show the supportive effects of endothelial cells on eosinophil differentiation, we examined the effects of cocultured HUVEC on IL-3 and IL-5-induced eosinophil differentiation from human umbilical cord blood CD34+ cells.

METHODS

CD34+ cells were obtained from the heparinized umbilical vein blood of 10 volunteers using a CD34-conjugated magnetic bead positive direct selection procedure. With HUVEC in Transwell, CD34+ cells were then cultured for 14-28 days. In neutralizing experiments on HUVEC-derived cytokines, antibodies to both stem cell factor (SCF) and granulocyte/macrophage colony-stimulating factor (GM-CSF) were added to the cell cultures.

RESULTS

Cocultured HUVEC upregulated IL-3 and IL-5-induced eosinophil differentiation from CD34+ cells on day 28 of culture by 75.0%. The eosinophilopoietic effect of HUVEC was significantly only when the cells were present in the culture from day 15 to day 28. Addition of anti-SCF antibody or anti-GM-CSF monoclonal antibody to the culture significantly suppressed HUVEC-combined IL-3- and IL-5-induced eosinophil differentiation on day 28 of culture by 49.2 and 55.0%, respectively.

CONCLUSIONS

These results indicate that several cytokines including GM-CSF and SCF from HUVEC promote IL-3- and IL-5-induced eosinophil differentiation from CD34+ cells.

Emergence of symbolic behavior from brain like memory with dynamic attention

An important feature of human intelligence is the use of symbols. This is seen in our daily use of language and logical thinking. However, the use of symbols is not limited to humans. We observe planned action sequences in primate behavior and prediction-based action in higher mammals. For the representation and operation of symbols by the brain neural circuit, no specific construction principle or computational theory is known so far. In this paper, we regard the brain as a complex of associative memory and dynamic attentional system, and starting from two hypotheses on information representation and operation in the brain, we propose a model of primitive symbolic behavior emergence that is consistent with the conventional symbolic processing model. We also describe a computational theory of the symbolic processing model in associative memory. Through computer simulation studies on a language-like memory search and map learning by a moving robot, we discuss the validity of the model.

Formation of cone mosaic of zebrafish retina

In the zebrafish retina, four types of cone photoreceptor cells (or cones) with different sensitive frequencies are arranged in a regular pattern, named "cone mosaic". A pair of small cones, one sensitive to red and the other sensitive to green, is in close contact and forms a "double cone". In addition, there are two kinds of single cones, sensitive to blue and to UV, respectively. We study characteristics of cell-differentiation rules that realize stable formation of cone mosaic. Assumptions are: undifferentiated cells are arranged in a regular square lattice, and they are one of the three types (B, U, and D cells). A D cell has two parts (G and R-parts) and takes one of the four directions. The cells change their cell type and orientation following a continuous-time Markovian chain. The state transtion occurs faster if it increases the stabilities of the focal cell, in which the stability is the sum of affinities with neighboring cells. After the transient period, the system may reach a stable pattern (pre-pattern). The pattern becomes fixed later when the cells are fully differentiated in which B cells, U cells, and D cells become blue-sensitive, UV-sensitive, and double cones, respectively. We search for the combinations of affinities between cell states that can generate the same cone mosaic patterns as in zerbrafish retina. Successful transition rules give (1) zero or small affinity with the pairs of cell states that are absent in the zebrafish cone mosaic (lambda(UR), lambda(BG)and the contact of two cells of the same type); (2) a large affinity between a part of D cells and a non-D cell (lambda(UG)and lambda(BR)); and (3) a positive affinity of an intermediate magnitude between two non-D cells (lambda(BU)) and between two parts of D cells (lambda(GR)). The latter should be of a magnitude of about 60-90% of the former. The time needed to form a regular pattern increases with the lattice size if all the cells start pre-pattern formation simultaneously. However, the convergence time is shortened considerably if the pre-pattern formation occurs only in a narrow band of morphogenetic cell layer that sweeps from one end of the lattice to the other.

N18 in median somatosensory evoked potentials: a new indicator of medullary function useful for the diagnosis of brain death

OBJECTIVES

To record N18 in median somatosensory evoked potentials (SEPs) for deeply comatose or brain dead patients and to demonstrate the usefulness of N18 for the diagnosis of brain death in comparison with auditory brain stem responses (ABRs) and P13/14 in median SEPs, which have been conventionally used as complementary tests for the diagnosis of brain death.

METHODS

Subjects were 19 deeply comatose or brain dead patients. Thirteen recordings were performed in deeply comatose but not brain dead conditions, and 12 recordings were performed in brain death. N18 was evaluated in the CPi-C2S lead (or other scalp-C2S leads) to obtain a flat baseline.

RESULTS

N18 was preserved in 12 of 13 non-brain dead comatose recordings whereas it was completely lost for all of the 12 brain death recordings. P13/14 in median SEPs was preserved for all the comatose recordings, whereas apparent P13/14-like potentials, usually of low amplitude, were seen in nine of 12 brain death recordings-that is, frequent false positives. The ABRs already showed features which were characteristic for brain death (loss of components other than wave 1 or small wave 2) for four comatose recordings, in three of which N18 was preserved. The last result not only corresponds with the fact that ABRs can evaluate pontine and midbrain functions and not medullary function, but further supports the medullary origin of N18. In the four patients followed up for the course of progression from coma to brain death, N18s preserved in normal size during the comatose state were completely lost after brain death was established.

CONCLUSIONS

The N18 potential is generated by the cuneate nucleus in the medulla oblongata in the preceding studies. N18 is suggested to be a promising tool for the diagnosis of brain death because there were no false positives and rare false negatives in the present series for detecting the remaining brain stem function.

Exacerbation of myasthenia gravis in a patient after interferon-beta treatment for chronic active hepatitis C

We report the case of a 53-year-old female patient, who developed bilateral blepharoptosis, limb weakness, dysphagia, and dyspnea several days after human natural interferon-beta (IFN-beta) treatment for chronic active hepatitis C. A positive edrophonium test, an elevated anti-acetylcholine receptor antibody titer, and decrements in the amplitude of muscle action potentials evoked by repetitive stimulation confirmed the diagnosis of myasthenia gravis (MG). Since she had been suffering from drooping of her right eyelid, fluctuating diplopia and easy fatiguability of limbs before receiving IFN-beta, her symptoms of MG were considered to be exacerbated by IFN-beta. It is recommended that IFN-beta should be used with particular care in patients with known MG or its compatible symptoms.

Estimating cell lineage from distributions of randomly introduced markers

Cell lineage of a multicellular organism has been analysed by introducing a genetic or chemical marker that is inherited from a cell to its daughter cells and is detectable even after several cell divisions. To construct a complete cell lineage, all the cells at different developmental stages need to be identified, and then the intracellular marker must be introduced to each cell. In this paper, I study a new method of estimating cell lineage based on distributions of intercellular markers observed at a single stage, which are introduced randomly at earlier stages. Assumptions are: (1) cell lineage is invariant between embryos; (2) a small number of cells are marked in each experiment; and (3) the total number of replicate experiments is sufficiently large. Then we identify the most likely cell lineage pattern (or tree topology) as the one that requires the least marker insertions to be compatible with the observed distributions of cell markers. This method is essentially the same as the principle of persimony widely used for ancestral phylogeny reconstruction in evolutionary biology. When the total number of cells is small, we can generate all the possible cell lineages and calculate the minimum number of marker insertions for each candidate, and then choose the cell lineage that requires the least marker insertions. If the number of cells is large, we can use clustering method in which a pair of cells with the highest correlation in marker labelling are merged sequentially. The efficiency of the clustering method in estimating the correct cell lineage is confirmed by computer simulations. Finally, the clustering method is applied to reconstruct the cell lineage of ascidian from experimental data.

Four novel mutations of the connexin 32 gene in four Japanese families with Charcot-Marie-Tooth disease type 1

DNA-based mutation analysis on the connexin 32 gene was performed in 49 families with Charcot-Marie-Tooth disease (CMT) type 1 but without duplication involving the chromosomal region, 17p12-p11.2. Mutations were identified in five of the 49 families, and four of the five mutations were hitherto undescribed: Va137Met, Glu57His, Arg142Glu, Val177Ala. X-linked CMT sometimes lacks evidence for X-linked transmission and cannot be differentiated from CMT type 2, especially in females with mildly decreased nerve conduction velocity. Therefore, molecular analysis is useful for molecular pathology of their disease.

P9 in median nerve SEPs is a junctional potential generated by the change of the volume conductor size between trunk and neck

OBJECTIVES

We aimed to investigate the origin of P9 in median SEPs by applying the junctional potential theory.

METHODS

We studied the distribution over the body surface with contralateral shoulder reference in 4 normal subjects.

RESULTS

A stationary potential field P9/tN9 (=truncal N9) was recorded: P9 over head and neck (the smaller part), tN9 over trunk (the larger part), the boundary being located between trunk and neck. This polarity agreed with that expected from simulation studies.

CONCLUSIONS

P9 is a junctional potential generated by the change of the volume conductor size between trunk and neck.

Cell-differentiation rules that generate regular mosaic patterns: modelling motivated by cone mosaic formation in fish retina

We study characteristics of cell-differentiation rules that realize stable formation of regularly arranged checker-board patterns, exemplified by cone "mosaic" zebrafish retina, or the regular arrangement of cone photoreceptor cells. We consider the situation in which cells are arranged on a square lattice and are initially undifferentiated. Later each cell becomes one of the two differentiated states, affected by the state of the neighboring cells. The cells that undergo differentiation form a "morphogenetic cell row" which sweeps from one end to the other end of the lattice through time. This models an outward sweep of the margin of expanding mosaic region of the retina which occurs as undifferentiated photoreceptor cells become differentiated in concentric circles, joining the mosaic. We introduce an index to measure the ability of cell-differentiation rules to generate regular checker-board patterns from irregular initial patterns, and attempt to characterize the successful rules. We first show the importance of six "preservation conditions" which guarantee perfectly regular photoreceptor arrangement for all the rows after a regular row. Then we select an additional six "optimizing conditions" for responses to configuration that are consistently shown by the rules of high average scores. We also examine the effect of interaction between responses to different configurations. Finally we examine the concept of morphogenetic row precedence, i.e. that the successful rules generating a high score tend to treat the consistency with neighbors in the newly differentiated cells (those in the morphogenetic cell row) as more important that the consistency with previously differentiated neighbors.

On rugged shape of skin tumor (basal cell carcinoma)

Basal cell carcinoma (BCC) is the most common cancer of the skin that is made of transformed basal cells of the human epidermis, and spreads along the epidermis--dermis junction. It often forms tumor cell mass that protrudes towards the dermal connective tissue with many branches. Histopathological examination of the cancer demonstrates the cell mass of a rugged shape appearing as many regular spaced islands in a two-dimensional section. We study the process of cell proliferation and spatial pattern formation of the skin tumor by a pair of partial differential equations of tumor cells and nutrients. The assumptions are: (1) proliferation rate of tumor cells depends on the availability of nutrients, which simply diffuse out of capillaries through connective tissue; (2) nutrients are consumed by active tumor cells; (3) cell diffusion coefficient expressing tumor cell movements increase with the cell density and the nutrient availability. Starting from the initial condition with a single layer of tumor cells. the model develops a smooth colony if n'0 is large, but a characteristic rugged spatial pattern of tumor cell mass if n'0 is small, in which n'0 is nutrient concentration multiplied by square root of growth efficiency divided by diffusion coefficient of nutrients. The proportion of the area occupied by tumor cells increases with n'0. The coefficient of variation in the width of "islands" of tumor cell mass is rather small (0.2 reverse similar0.6), implying the regularity of the spatial pattern. We also analyses the photographs of a two-dimensional section of tumor cell mass and compare the spatial patterns generated by the model.

Three-dimensional tactile display for the blind

A tactile display device that can present tangible relief graphics for visually impaired persons has been developed. The tactile surface consists of a 64 x 64 arrangement of tactorpins with 3 mm interspacing. The tactor-pins are aligned in a hexagonal, rather than a square formation, to assure smooth depiction. The matrix has a total area of 200 mm x 170 mm. Each pin can be raised in 0.1 mm steps to a maximum height of 10 mm. Users can get certain information by touching the pins raised at varying heights with fingers and/or palms. Laboratory assessment of the device with six blind subjects showed its ability to transmit various kinds of information.

Cell-cell adhesion in limb-formation, estimated from photographs of cell sorting experiments based on a spatial stochastic model

We developed a new method to estimate the magnitude of differential cell-cell adhesion of two tissues based on the spatial patterns in cell-sorting experiments, and applied it to experimental data on progress-zone cells of avian limb bud at stages 20-26. The change in cell distribution in the experiment was recorded, and statistics qB/B for the degree of cell sorting was calculated from the photographs. Based on extensive computer simulations of spatial Markov processes on a 2-D lattice, we derived a formula for qB/B increasing with time. Using least square fitting, differential adhesion A and cell motility m are estimated from the time series data of qB/B obtained from the experiment. The estimated A was close to 0 (the spatial pattern remained random) if the mixed cells were from two tissues of the same stage. If the mixed cells were from different stages, and the estimated A was positive (cell sorting occurred). Estimated A increased with the difference in the stage number of the two tissues from which the cells were sampled. This result can be explained both by the stage-specific change in adhesion molecules and by a linear increase (or decrease) in the amount of adhesion molecules on cell surface.

Inhibitory effect of F-1322 on allergic eosinophil infiltration in airways

The effects of F-1322 (N-[2-[4-(benzhydryloxy)piperidino]ethyl]-3-hydroxy-5-(3-pyridy lmethoxy)-2-naphthamide) on antigen-induced eosinophil infiltration and interleukin-5 production in the airways and on in vitro eosinophil migration were investigated. F-1322 (10-30 mg/kg, p.o.) inhibited antigen-induced eosinophil infiltration and interleukin-5 production in the airways of sensitized mice in a dose-dependent manner. Furthermore, F-1322 (0.1-10 microM) prevented the in vitro migration of eosinophils from guinea-pigs and humans induced by recombinant human interleukin-5, platelet-activating factor, and leukotriene B4 in a concentration-dependent manner. These results indicate that F-1322 has an inhibitory effect on allergic eosinophil infiltration of the airways by preventing both eosinophil migration and interleukin-5 production. These pharmacological profiles suggest that F-1322 will be a useful therapeutic for allergic diseases, especially asthma.

Horner's syndrome associated with mononeuritis multiplex due to cytomegalovirus as the initial manifestation in a patient with AIDS

We report on a 60-year-old male with AIDS who presented Horner's syndrome that was associated with mononeuritis multiplex due to cytomegalovirus (CMV) infection. This is the first case who presented Homer's syndrome in the course of AIDS. Horner's syndrome associated with mononeuritis multiplex in this patient was the initial manifestation without any opportunistic infections. Since Horner's syndrome and mononeuritis multiplex in the present case were both improved by ganciclovir, it is important to consider CMV infection when Horner's syndrome or mononeuritis multiplex is observed in immunocompromised patients, such as those with HIV-1 infection or AIDS, even if they do not show any other opportunistic infections.

Modeling spatio-temporal patterns generated by Bacillus subtilis

Colonies of bacteria, Bacillus subtilis, that grow on the surface of thin agar plates show various morphological patterns in response to environmental conditions, such as the nutrient concentration, the solidity of an agar medium and temperature. For instance, the colony pattern shows a dense-branching morphology with a smooth circular envelope (DBM-like) in a nutrient-poor semi-solid agar medium, and it turns to a simple disk-like colony as both the nutrient concentration and the agar's softness increase. These patterns have been shown to involve cell movement inside colonies. In a DBM-like colony, individual cells actively move, particularly in the expanding periphery of the colony, while they become immotile at the inner region of the colony where nutrient is very low. In a disk-like colony, cells are highly active in the whole region of the colony. Based on such experimental observations, we develop a diffusion-reaction model, in which density dependent cell movements are incorporated by the level of nutrient concentration available for the cell. Numerical simulations of the model under different environmental conditions closely reproduce various colony patterns ranging from DBM-like pattern to the homogeneous disk-like one in a unifying manner. The analysis also predicts the growth velocity of a colony as a function of the nutrient concentration.

[Resection of multiple thymoma: a case report]

A 74-year-old male, who had been treated for hypertension at the out-patient clinic, was admitted to our hospital because of an abnormal shadow on a chest radiograph. After diagnosis of thymoma by needle biopsy surgery was carried out on July 6, 1995, when an extended thymectomy along with removal of the entire tumor was done. During the surgery it was noticed that there was not one, but two independent tumors located in the anterior mediastinum, the upper left portion was growing from the level of the crania to the left brachiocephalic vein, whereas the lower right portion was growing towards the right thoracic cavity in front of the pericardium. Both tumors were encapsulated firmly, and connected to each other by scantly loose connective tissues. There was no continuity or sarring between the two tumors. Histologically both were diagnosed to be lymphocytic thymoma. We believe that this case is a good example of multiple thymomas and provides evidence of the potential multicentricity of thymoma. It is possible that extended thymectomy may be seeded for a complete resection of thymomas.

[Non-uremic neuropathy in hemodialysis patients]

We have reviewed 20 clinical records of hemodialysis patients with neuropathy admitted to the Department of Neurology during 1978 april through 1995 march. The clinical diagnosis was made based on clinical findings, neurophysiological examinations, and histopathological findings of sural nerve and peroneal muscle biopsies. Four out of twenty hemodialysis patients with neuropathy were non-uremic neuropathy. The diagnosis of neuropathy of four patients were chronic inflammatory demyelinating polyneuropathy, neuropathy with graft versus host disease, Guillain-Barré syndrome, and subacute combined degeneration of the spinal cord. All patients improved after the treatment. It is important to consider the possibility of association of non-uremic neuropathy in hemodialysis patients.

[A case of left subclavian artery occlusion with transient ischemic attacks probably in the internal carotid artery system]

The subclavian steal syndrome is known to steal blood flow from the vertebrobasilar system. However, we experienced a case of subclavian artery occlusion presenting transient ischemic attacks in left internal carotid system. A left handed 41-year-old man developed transient dysarthria and right hemiparesis including face several times when he physically used his arms. He had no symptoms of the vertebrobasilar system. A brain MRI revealed an old cerebral lacuna at the left putamen supplied by perforating arteries of the middle cerebral artery. The angiography demonstrated a complete occlusion of the proximal portion of the left subclavian artery without a reverse flow from the vertebral artery. Instead, descending cervical branches and deep cervical branches of the ipsilateral external carotid artery supplied collateral pathways to the occluded subclavian artery. On the basis of above observations, we speculated that he developed symptoms of the internal carotid system due to the steal through the collateral network of the cervical arteries directed to the subclavian artery. We should consider not only the vertebrobasilar system but also the internal carotid system, especially its cervical artery network, when exploring collateral pathways for the subclavian steal syndrome.

[Striatonigral degeneration]

Striatonigral degeneration (SND) is sporadic, middle-aged on set degenerative disease of the nervous system which etiology is unknown. SND is considered one of multiple system atrophy (MSA). Clinically parkinsonian symptom is dominant and then it is difficult to distinguish from idiopathic Parkinson's disease (PD). Pathologically neuron cell loss and gliosis are recognized principally striatum (mainly putamen) and substantia nigra. Putaminal hypointensity and slit-hyper intensity in the outer margin of putamen are often seen on T2-weighted 1.5 Tesla MRI. PET with [18 F] fluorodeoxyglucose indicates a considerably decreased glucose utilisation in the striatum of SND, whereas glucose utilisation are normal in PD. Striatal dopamine D1, D2 receptors are reduced. Response to Levodopa is poor or absent.

Amyloid load and neural elements in Alzheimer's disease and nondemented individuals with high amyloid plaque density

The amyloid burden and relationship between amyloid deposits and neural elements were investigated in sections of prefrontal neocortex from eight Alzheimer's disease (AD) patients and four age-matched nondemented controls with high amyloid plaque density (HPND). Computer-based image analysis revealed that the total area occupied by betaA4 immunoreactivity was significantly greater (P < 0.031) in AD (27.1%) than in HPND (14.5%) sections. The total betaA4-positive area occupied by nondiffuse plaques was significantly greater (P < 0.05) in AD (13.6%) than in HPND (5.2%) sections. The percentage of diffuse (DPs) and nondiffuse plaques (NDPs) which contained neurons, astrocytes, microglia, dystrophic neurites, and amyloid precursor protein (APP) was also determined. The frequency of association between betaA4 and these neural elements was similar between AD and HPND cases in both diffuse and nondiffuse plaques. Forty percent of DPs in AD and HPND sections contained neuronal perikarya. Microglia, dystrophic neurites, and APP were detected in most nondiffuse plaques in both AD and HPND sections. While astrocyte cell bodies were not present in either diffuse or nondiffuse plaques, their processes were detected in most. These findings indicate that amyloid deposition and nondiffuse plaques are greater in AD than in HPND sections. The association between microglia and nondiffuse plaques supports the hypothesis that these resident immune cells participate in aggregation and redistribution of amyloid deposits and possibly formation of dystrophic neurites.

A new blood compatible and permselective hollow fiber membrane for hemodialysis

The authors have prepared a blood compatible and highly permselective hemodialysis membrane composed of polyether segmented nylon. This block copolymer was synthesized by polycondensation of bis-3-aminopropyl-poly(tetramethylene oxide) (PTMO) and poly(imino-1,3-bismethyl-cyclohexyl-iminoisophtharoyl) (NyBl) prepolymer obtained by polycondensation of 1,3-bis(aminomethyl)cyclohexane (B) and isophthalic acid (I). The molecular weight (MW) calculated from the number of end-groups was 16,000-21,000. In vitro blood compatibility was evaluated in terms of platelet adhesion onto the surface. PTMO-NyBl surfaces showed excellent platelet adhesion preventing properties. The PTMO-NyBl hollow fiber membrane was obtained by a dry-wet spinning process. The membranes had higher permeability coefficients for macromolecules ranging from MW 10,000 to 20,000 than polysulfone hollow fiber membrane (PS membrane), and had acceptably low albumin permeability for use as a dialysis membrane. The ex vivo blood compatibilities of PTMO-NyBl membrane and PS membrane were investigated by extracorporeal circulation in a pig model. The PTMO-NyBl membrane gave excellent results when assessing hemodialysis leukopenia, oxidative burst, and free platelet count decrease.

The evolution of genomic imprinting

In some mammalian genes, the paternally and maternally derived alleles are expressed differently: this phenomenon is called genomic imprinting. Here we study the evolution of imprinting using multivariate quantitative genetic models to examine the feasibility of the genetic conflict hypothesis. This hypothesis explains the observed imprinting patterns as an evolutionary outcome of the conflict between the paternal and maternal alleles. We consider the expression of a zygotic gene, which codes for an embryonic growth factor affecting the amount of maternal resources obtained through the placenta. We assume that the gene produces the growth factor in two different amounts depending on its parental origin. We show that genomic imprinting evolves easily if females have some probability of multiple partners. This is in conflict with the observation that not all genes controlling placental development are imprinted and that imprinting in some genes is not conserved between mice and humans. We show however that deleterious mutations in the coding region of the gene create selection against imprinting.