New variant of congenital dyserythropoietic anemia with trilineage myelodysplasia

We report the case of a male infant with a variant of congenital dyserythropoietic anemia (CDA), who developed severe hyperbilirubinemia on the day of birth, subsequent severe anemia, and hyperferritinemia. Bone marrow and laboratory examinations revealed features of CDA including trilineage myelodysplasia and erythroblasts with a binucleated nuclear morphology and ineffective erythropoiesis. The CDA in this patient was assumed to be a new variant type because of: the lack of internuclear chromatin bridges in the erythroblasts with abnormal nuclear morphology; a negative acid serum test; the presence of erythrocyte antigen I, and the effect of splenectomy. Trilineage myelodysplasia in CDA is not known. An abnormality in the stem cells was suggested to be the cause of CDA in this case.

Neuroimaging study of myotonic dystrophy. II. MRI measurements of the brain

The brain of patients with adult type myotonic dystrophy was measured using MRI, and compared with age- and sex-matched controls. The width of the cerebrum, and the areas of the corpus callosum, pons and pituitary gland were significantly smaller in adult-type myotonic dystrophy than in the controls. The IQ of the patients with adult-type myotonic dystrophy was lower than that of controls. These results demonstrate a decreased volume of the brain and pituitary glands in myotonic dystrophy. These findings suggest a causal relationship for the mental retardation and endocrine dysfunction that may occur.

DNA diagnosis of pyruvate dehydrogenase deficiency in female patients with congenital lactic acidaemia

The diagnosis of pyruvate dehydrogenase (PDH) E1 alpha deficiency, which is an X-linked inborn error of metabolism, is usually established by the measurement of PDH complex activity in cultured cells. However, heterozygous female patients with PDH E1 alpha deficiency may be misdiagnosed when the normal X chromosome is predominantly expressed in the cultured cells. Therefore, in female patients with convincing clinical presentations of PDH E1 alpha deficiency and the normal enzyme activity, the X-inactivation pattern should be analysed and the PDH E1 alpha gene screened for mutations. For this screening, we applied the method of single-strand conformational polymorphism (SSCP) and DNA sequencing and examined 11 female patients with congenital lactic acidaemia whose PDH complex activity was normal in cultured cells. In 2 of the 11 female patients, we found distinct pathogenic missense mutations in the PDH E1 alpha gene (G89S and G291R). Both affected patients showed a similar clinical presentation and had been diagnosed as West syndrome. In 3 of the 11 patients, we found a polymorphic base-pair substitution in exon 9 of the PDH E1 alpha gene which resulted in a changed amino acid residue (M282L). We conclude that PCR-SSCP analysis of the PDH E1 alpha gene, followed by DNA sequencing, is a useful method to screen for mutations of the PDH E1 alpha gene in female patients with congenital lactic acidaemia who have normal enzyme activities in available samples, normal ratio of lactate to pyruvate, and predominantly raised lactate concentration in cerebrospinal fluid.

A substrate of ecto-protein kinase is microtubule-associated protein 1B in cortical cell cultures undergoing synaptogenesis

Synapse formation between cultured rat cortical neurons is inhibited by the continuous application of K-252b, an ecto-protein kinase inhibitor, which cannot permeate the cell membrane. In order to identify the phosphorylated membrane proteins which are necessary for synapse formation, endogenous substrates for ecto-protein kinase activity were investigated. To detect phosphorylation of proteins containing extracellular domains, [gamma-33P]ATP was applied to the medium for brief periods. Proteins were then separated by SDS polyacrylamide gel electrophoresis and detected by autoradiography. Some bands showed immediate phosphorylation and this phosphorylation was suppressed by the addition of K-252b to the medium. We examined partial amino acid sequences of these substrates. The band with the highest molecular weight, whose phosphorylation was strongly inhibited by K-252b, was identified as microtubule-associated protein (MAP) 1B. These results suggest the possibility that the phosphorylation of extracellular domains of MAP1B is involved in synaptogenesis between cortical neurons.

Defective T cells from gld mice play a pivotal role in development of Thy-1.2+B220+ cells and autoimmunity

The gld mouse represents a fascinating animal model of autoimmune disease, which is characterized by massive development of Thy-1.2+B220+ CD4-CD8- cells. These cells thus have double positive markers for T and B cells, but are double negative for CD4 and CD8 markers and are thus designated DN cells in the present context. An additional important feature in gld mice is a defect in expression of Fas ligand. To investigate the regulatory role of bone marrow-derived cells for the development of these DN cells and of gld autoimmunity, we constructed chimeric mice transplanted with fetal liver cells or fetal thymus from gld mice into nonirradiated severe combined immunodeficient (SCID) mice. These chimeric mice regenerated, developed both these DN cells and the gld autoimmune syndrome and also generalized lymphoproliferative disorders. However, when fetal liver cells from both gld and non-gld mice (C57BL/10 Thy-1.1 mice) were co-transplanted into SCID mice, the development of DN cells was apparently inhibited. Further, this inhibition was also seen in SCID mice that had been grafted with both gld and non-gld fetal thymus revealing the pivotal role played by T cells in development of DN cells. When B cells purified from non-gld (C3H+/+) mice were transplanted into SCID mice grafted with gld fetal thymus, the development of DN cells was not inhibited. Taken together, these findings indicate that T cells from non-gld mice inhibit the expression of gld features, e.g., lymphoproliferation, immune-based nephritic disease, and autoantibody production. These findings also suggest that the Fas ligand is selectively expressed on T cells.

Defective T cells from gld mice play a pivotal role in development of Thy-1.2+B220+ cells and autoimmunity

The gld mouse represents a fascinating animal model of autoimmune disease, which is characterized by massive development of Thy-1.2+B220+ CD4-CD8- cells. These cells thus have double positive markers for T and B cells, but are double negative for CD4 and CD8 markers and are thus designated DN cells in the present context. An additional important feature in gld mice is a defect in expression of Fas ligand. To investigate the regulatory role of bone marrow-derived cells for the development of these DN cells and of gld autoimmunity, we constructed chimeric mice transplanted with fetal liver cells or fetal thymus from gld mice into nonirradiated severe combined immunodeficient (SCID) mice. These chimeric mice regenerated, developed both these DN cells and the gld autoimmune syndrome and also generalized lymphoproliferative disorders. However, when fetal liver cells from both gld and non-gld mice (C57BL/10 Thy-1.1 mice) were co-transplanted into SCID mice, the development of DN cells was apparently inhibited. Further, this inhibition was also seen in SCID mice that had been grafted with both gld and non-gld fetal thymus revealing the pivotal role played by T cells in development of DN cells. When B cells purified from non-gld (C3H+/+) mice were transplanted into SCID mice grafted with gld fetal thymus, the development of DN cells was not inhibited. Taken together, these findings indicate that T cells from non-gld mice inhibit the expression of gld features, e.g., lymphoproliferation, immune-based nephritic disease, and autoantibody production. These findings also suggest that the Fas ligand is selectively expressed on T cells.

Amelioration of rewarming ischemic injury of the pancreas graft during vascular anastomosis by increasing tissue ATP contents during preservation by the two-layer cold storage method

Rewarming ischemic injury during vascular anastomosis severely compromises posttransplant pancreas graft survival because the graft has already been subjected to warm and cold ischemia before vascular anastomosis. We examined whether preservation of the pancreas graft by the two-layer method ameliorates rewarming ischemic injury of the graft during vascular anastomosis and also investigated the energy metabolism of the pancreas graft before, during and after rewarming ischemic period. After flushing with cold University of Wisconsin solution (UW), the pancreas grafts were preserved by the two-layer (UW/perfluorochemical [PFC]) method (group 1) or simple cold storage in UW (group 2) for 24-hr and then autotransplanted. In control, the pancreas grafts were flushed out with cold UW and immediately autotransplanted without preservation (group 3). After completion of vascular anastomosis, vascular clamp was not released until 90, 120, or 150 min of rewarming ischemia, including anastomosis time, has elapsed. After 90 min of rewarming ischemia, graft survival rates were 5/5, 100%, 5/5, 100%, and 5/5, 100% in groups 1, 2 and 3, respectively. After 120 min, all the grafts in groups 2 and 3 failed (0/5, 0%, and 0/5, 0%, respectively), however, all the grafts in group 1 survived (5/5, 100%). Even after 150 min, 1 of 3 grafts in group 1 survived (1/3, 33%). After 24 hr preservation, tissue adenosine triphosphate (ATP) and total adenine nucleotides (TAN) levels of the grafts in group 1 were about 2-fold the reference values before harvesting and significantly higher compared with group 2(p < 0.05; p < 0.05). After 120 min of rewarming ischemia, tissue ATP levels in group 1 were 84% of the reference values and significantly higher compared with group 2(p < 0.05). TAN levels of group 1 were also significantly higher compared with group 2(p < 0.05). Two hours after reperfusion, ATP and TAN levels in group 1 were significantly higher than group 2(p < 0.05). There were no remarkable difference between group 1 and group 2 concerning adenosine diphosphate (ADP), adenosine monophosphate (AMP) levels. We conclude that the two-layer (UW/PFC) method ameliorates rewarming ischemic injury of the pancreas graft during vascular anastomosis by increasing tissue ATP concentration and TAN levels during preservation and maintaining tissue ATP and TAN levels during vascular anastomosis. Consequently, ATP levels are rapidly recovered after reperfusion and the graft survives.

Reinforcement of cyclosporin A-induced red cell destruction by superoxide

To determine the mechanism of hemolysis following organ transplantation, we studied the effect of immunosuppressants and/or superoxide (SO) on the in vitro destruction of red cells. The immunosuppressants tested included cyclosporin A (CyA), deoxyspagarine (DSG), and FK506. SO was obtained from the hypoxanthine-xanthine oxidase reaction. Of the three immunosuppressants studied, only CyA affected the size of red cells and directly produced hemolysis in an isotonic buffer without the involvement of an immune mechanism. In addition, SO and CyA showed a synergistic effect on hemolysis during prolonged incubation. Catalase and allopurinol prevented hemolysis by counteracting the activity of SO. In that SO is produced in excess during the recovery of blood flow after organ transplantation, the prolonged contact of red cells with CyA and SO may be involved in the development and reinforcement of hemolysis in vivo.

In situ demonstration of the HTLV-I genome in the spinal cord of a patient with HTLV-I-associated myelopathy

Using polymerase chain reaction (PCR) and in situ hybridization, we investigated the HTLV-I genome in the CNS of an HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patient with a 20-year disease duration. Neuropathologically, there was severe white matter degeneration throughout the spinal cord, but lymphocytic infiltrates were not evident in any lesion. PCR amplification of the pX region of HTLV-I DNA detected its sequence in the spinal cord and all extra-CNS tissue samples. In situ hybridization using probes complementary to the pX and gag regions detected the HTLV-I genome in the cytoplasm and nucleus of cells in the thoracic cord. The findings indicate a direct involvement of HTLV-I in the neurodegeneration of HAM/TSP.

Periodic maternal deprivation alters stress response in adult offspring: potentiates the negative feedback regulation of restraint stress-induced adrenocortical response and reduces the frequencies of open field-induced behaviors

The effects of periodic maternal deprivation (PMD) treatment on the adrenocortical stress response and on open-field behavior in adult offspring were investigated. Sprague-Dawley rat pups were deprived of mothers daily for 4.5 h during the first 3 weeks of life. PMD treatment resulted in lower corticosterone levels during restraint stress later in life. The result of dexamethasone suppression test indicated that PMD treatment caused a potentiation of the negative feedback function of adrenocortical response. These effects of PMD were not accompanied by an increased density of the hippocampal glucocorticoid receptor which has been reported to be induced in neonatal handling treatment (brief 15-min maternal deprivation). Serotonin (5-HT)-2 and beta-adrenergic binding sites were also examined in cerebral cortex and no change of binding capacities were induced by PMD treatment. In the open-field test, PMD treatment decreased the number of ambulations and rearings but did not affect a frequency of defecation. From these results, it is suggested that PMD treatment leads rats to be insensitive to environmental stimuli in adulthood.

Interaction between dibucaine and pig erythrocyte membranes as studied by NOESY experiments in 1H-NMR spectroscopy. Which form of dibucaine interacts more strongly, cationic or uncharged?

The interaction between amine local anesthetic dibucaine and pig erythrocyte membranes has been studied by 1H-NMR spectroscopy. Two-dimensional NOESY spectra were observed to obtain the conformations of cationic and uncharged forms of dibucaine. The NMR spectra were measured at pH 7.4, and the temperature was raised (318-348 K) to increase the concentration of the uncharged form of dibucaine, taking the temperature dependence of the pKa value of dibucaine into consideration. The dibucaine in a buffered solution showed the presence of two kinds of distinctly different species; one is assignable to the cationic form and the other to the uncharged form of dibucaine, suggesting that the protonation equilibrium between the two forms is slow in the presently employed experimental condition. The uncharged dibucaine showed well-defined NOE cross-peaks in the NOESY spectra of the solution containing no erythrocyte membranes, suggesting that its conformation is relatively fixed. Interestingly, however, it was only the cationic dibucaine that showed NOE cross-peaks when the solution contained the membranes, and experiments were performed at a much shorter mixing time for the buildup of NOEs, suggesting that it appeared only the cationic form of dibucaine is interacting with the membranes. It was concluded that the uncharged form of dibucaine, which was produced by raising the temperature, formed micelles in a buffered solution. Thus formed micelles didn't interact with membranes owing to the repulsive forces between the structured water surrounding the micelles and those at the surface of the membranes. This conclusion could be a promising reason why the cationic local anesthetics are much more active than their uncharged counterparts in blocking nerve conduction.

Infantile spasms with predominantly unilateral cerebral abnormalities

To investigate the pathogenesis of infantile spasms, 12 children underwent a combination of neurophysiologic and neuroimaging studies including brainstem evoked potentials and single photon emission computed tomography with 99mTcHMPAO. Three of the children had localized cerebral abnormalities on neuroimaging, i.e. right frontotemporal cortical microdysgenesis, left frontotemporal polymicrogyria, and right parietooccipitotemporal porencephalic cyst. Neurophysiologic studies also indicated that a single cerebral hemisphere was predominantly involved, while the other hemisphere and the brainstem were relatively spared, a result compatible with the clinical findings of hemiparesis and hemiconvulsion. In these three patients, administration of carbamazepine was followed by marked improvement of the clinical and electroencephalographic findings. Our results suggest that a combination of noninvasive examinations can distinguish a particular subtype of infantile spasms associated with a localized cerebral abnormality and responsive to carbamazepine.

Serologic, virologic, and histologic characteristics of chronic phase hepatitis C virus disease in children infected by transfusion

OBJECTIVE

We studied the time course of hepatic dysfunction, seropositivity to hepatitis C virus (HCV) antibodies, viremia, and histologic evidence of hepatic injury to evaluate the course of HCV infection in children infected by blood transfusion.

PATIENTS AND METHODS

Twenty-nine patients (ages 4 to 18 years) who underwent open-heart surgeries for congenital heart disease were grouped into three categories based on alterations in serum alanine aminotransferase (ALT) levels: Group A, acute infection; Group B, subacute infection; and Group C, chronic infection.

RESULTS

In Group C, all 13 patients had detectable HCV RNA in serum. In contrast, all patients in Group A had no detectable HCV RNA: In Group B, one of nine patients had detectable HCV RNA and two of four patients examined had persistent chronic hepatitis by histologic criteria. Antibodies directed against C100-3 antigen or core-antigen were more useful than second-generation HCV antibody assays in determining the relationship between viremia and immunologic response. Infection with HCV genotype II and the presence of higher HCV RNA copy numbers were associated with histologic evidence of hepatic damage.

CONCLUSION

An abnormal ALT value is frequently associated with viremia, and biochemically resolved acute infection reflects clearance of HCV. However, a normal ALT does not always reflect an absence of hepatocyte damage and HCV replication in patients with subacute disease. The measures outlined in this study are useful indicators of disease activity during the chronic

Post-transfusion chronic hepatitis C in children

Two hundred and twenty-six patients who received blood products for open-heart surgery in childhood were screened by a second-generation enzyme-linked immunosorbent assay and with surrogate markers for hepatitis C virus (HCV) infection, such as alanine aminotransferase (ALT). Twenty-two (14%) of the 161 recipients who received blood products before 1989 and none of the subjects who had received blood products after 1990 (the year that the blood bank began to screen for HCV antibody) were HCV seropositive. Virologic and histologic studies showed that 10 (45%) of 24 seropositive patients had persistent hepatitis C virus infection, many with ongoing hepatitis. The remaining 12 seropositive patients with absent HCV RNA had normal ALT levels, indicating resolved hepatitis C infection. Enrolment in screening is important to detect chronic hepatitis C in children who received blood products prior to screening of blood donors for HCV antibody.

Vitamin D-dependent rickets type II: regulation of human osteocalcin gene expression in cells with defective vitamin D receptors by 1,25-dihydroxyvitamin D-3, retinoic acid, and triiodothyronine

The vitamin D receptor (VDR) is a nuclear transcription factor which binds to the vitamin D response element (VDRE) of the human osteocalcin gene and regulates its expression. Humans with VDR gene mutations, ever among those with the same point mutation in their VDR gene, demonstrate clinical heterogeneity. In addition, in some patients with these mutations, rickets has not recurred following cessation of therapy during follow-up ranging from 6 to 24 years. While important, it is likely that the VDR protein is not the sole factor in the development of rickets. To try to understand these clinical findings, the complex formed between the VDRE and one or more proteins in the nuclear extracts of cultured skin fibroblasts treated with 1,25-dihydroxyvitamin D-3 (1,25(OH)2D3), retinoic acid (RA), and/or triiodothyronine (T3) was investigated since such complexes are likely to precede the transcription of the VDR gene. Complex formation in the control cells with an intact VDR was increased by treatment with either 0.1 nM, 1 nM, 10 nM 1,25(OH)2D3, 100 nM RA, or 100 nM T3; however, combinations of these compounds did not produce an additive effect. In cells of affected patients, 1,25(OH)2D3, RA, or T3 increased complex formation, while no combination had an additive effect. These results indicate that 1,25(OH)2D3, RA, and T3 play a role in the regulation of bone remodeling through modulating the formation of protein complexes on the VDRE. Therefore, the clinical observations in patients with a VDR mutation might be explained at least in part by the overlapping control of osteocalcin expression by 1,25(OH)2D3, RA and T3.

[CD classification of lymphocytes and the function: significance of flow cytometric analysis in immunoneurological disorders]

We reviewed flow cytometric studies of lymphocyte subsets by using monoclonal antibodies in various immunoneurological disorders. In multiple sclerosis, most studies indicated decreases of suppressor T cells and suppressor-inducer T cells in both peripheral blood and cerebrospinal fluid (CSF). In HTLV-I-associated myelopathy, our studies showed an increase of CD28-negative cytotoxic T cells in the CSF, indicating the involvement of dysfunctioned cytotoxic T cells in the spinal cord lesion formation. In myasthenia gravis, the disease-specific finding is the appearance of CD4+ CD8+ (double positive) T cells in the peripheral blood, which may be associated with thymic abnormalities. These flow cytometric studies in immunoneurological disorders thus provide an insight in the pathogenesis of immunoneurological disorders.

Effects of rhG-CSF (filgrastim) on the recovery of hematopoiesis after high-dose chemotherapy and autologous peripheral blood stem cell transplantation in children: a report from the Children's Cancer and Leukemia Study Group of Japan

In a nonrandomized study, hematopoietic recovery kinetics were evaluated in 98 consecutive patients who underwent high-dose chemotherapy without total body irradiation (TBI) and autologous peripheral blood stem cell transplantation (PBSCT). Fifty-three patients received recombinant human granulocyte colony-stimulating factor (rhG-CSF) (filgrastim) therapy after PBSCT, and the data were compared by actuarial analysis to those of 45 historic controls. The number of days required to achieve a white blood cell count (WBC) of 1 x 10(9)/L, an absolute granulocyte count (AGC) of 5 x 10(8)/L, and a platelet count (PLT) of 5 x 10(10)/L were, respectively, 12.8 +/- 6.4 (mean +/- standard deviation [SD]), 13.4 +/- 6.4, and 49.2 +/- 78.2 in treated patients vs. 12.8 +/- 4.6, 14.4 +/- 10.3, and 31.4 +/- 38.8 days in historic controls, with no significant differences. There was no significant difference between the average number of days with fever in the treated group (6.0 +/- 6.6) and that in the control group (4.0 +/- 2.8). All febrile episodes responded promptly and successfully to parenteral antibiotic therapy. Thus, the data may suggest the possibility that therapy with filgrastim has only a limited ability to enhance hematopoietic recovery after PBSCT. To confirm this notion, we initiated a prospective randomized trial by recruiting a larger number of patients.

Aggregation of amyloid beta-protein and its neurotoxicity: enhancement by aluminum and other metals

The aggregation of amyloid beta-protein has been suggested to enhance its neurotoxicity in cultured hippocampal neurons. We found that aluminum, an epidemiologic risk factor for Alzheimer's disease, promoted the aggregation of synthetic amyloid beta-protein (beta 1-40) using immunoblotting and centrifugation. There were no significant changes by Ca or Mg. Other metals including Zn, Fe caused the small degree of aggregation compared to Al. Furthermore, beta 1-40 which was aggregated by aluminum was applied on cultured rat hippocampal neurons, and the characteristic deposition of amyloid fibrils was observed on cultured neurons. These results suggested that the degeneration of neurons and the deposition of amyloid beta-protein were enhanced by aluminum.

[Gut mucosal immunity and oral tolerance]

The biological phenomenon that experimental animals become hyporesponsive to a particular protein antigen, when orally administered, is called oral tolerance. A breakdown of oral tolerance to dietary antigens may be related to food allergy. Conversely, the induction of oral tolerance by feeding autoantigens, such as myelin basic protein, protects animals from subsequent immunization by this antigen resulting in development of experimental autoimmune encephalomyelitis, which is a disease model of the human demyelinating disease, multiple sclerosis (MS). The mechanism of oral tolerance could be an induction of suppressor cells, which release inhibitory cytokines including transforming growth factor beta, when triggered antigen-specifically and/or clonal anergy to fed antigen. Against this background, patients with MS and rheumatoid arthritis are on a clinical trial with bovine myelin and type II collagen feeding, respectively. Oral tolerance could be a part of the mainstream in future treatment strategies for human diseases with autoimmune etiologies.

[Development of the brainstem and cerebellum in autistic children]

Studies of magnetic resonance images have revealed morphological disorders of the brainstem and cerebellum in autistic children and adults. When we studied development of the brainstem and cerebellum in autistic patients, these structures were significantly smaller in autistic patients than in controls. Although the brainstem and cerebellum significantly increased in size with age in both groups, the development of the pons, cerebellar vermis I-V and cerebellar vermis VI-VII was significantly more rapid in autistic patients than in controls. However, the development of the other brain structures in the posterior fossa did not differ between autistic patients and controls. The regression intercepts of the brainstem and cerebellum as well as those of their components were significantly smaller in autistic patients than in controls. These results suggested that significant anatomical changes took place in the posterior fossa brain structures in the prenatal period in autistic children, but were not progressive.