[Clinicopathologic study of calcified aortic valve stenosis in the aged, and evaluation of the indications for percutaneous aortic balloon valvuloplasty]

OBJECTIVES

We performed clinicopathologic study of 56 aged patients with calcified aortic valve stenosis and investigated the indications for percutaneous aortic balloon valvuloplasty.

METHODS

The patients were 24 men and 32 women with a mean age of 81.9 years, who were classified into the following 3 types by etiology: 33 patients (58.9%) had senile aortic stenosis, 10 patients (17.9%) had bicuspid aortic stenosis, and 13 patients (23.2%) had rheumatic aortic stenosis. The sites of calcification were divided into the following 3 categories: cusp bases (base type), free edges (edge type), and both bases and edges (mixed type).

RESULTS

Among the 33 patients with senile aortic stenosis, 10 (30.3%) had calcification of base type, 2 (6.1%) of edge type and 21 (63.6%) of mixed type. Among the 10 patients with bicuspid aortic stenosis, one (10%) had calcification of base type and 9 (90%) of mixed type. Among the 13 patients with rheumatic aortic stenosis, 3 (23.1%) had calcification of edge type and 10 (76.9%) of mixed type. In addition, 2 or 3 commissures were fused in patients with rheumatic aortic stenosis. The cusps of the aortic valves in the bicuspid type were the most severely thickened among the 3 groups. Soft X-ray imaging showed the aortic valves of rheumatic aortic stenosis were the most severely calcified (calcification score: 2.4), followed by those of bicuspid aortic stenosis (1.9) and senile aortic stenosis (1.6).

CONCLUSIONS

Percutaneous aortic balloon valvuloplasty is most suitable in patients with calcified senile aortic stenosis because of the milder calcification, compared with those of the other 2 types.

Identification of CD72 as a lymphocyte receptor for the class IV semaphorin CD100: a novel mechanism for regulating B cell signaling

We have identified the lymphocyte semaphorin CD100/Sema4D as a CD40-inducible molecule by subtractive cDNA cloning. CD100 stimulation significantly enhanced the effects of CD40 on B cell responses. Administration of soluble CD100 markedly accelerated in vivo antigen-specific antibody responses. CD100 receptors with different binding affinities were detected on renal tubular cells (K(d) = approximately 1 x 10(-9)M) and lymphocytes (K(d) = approximately 3 x 10(-7)M). Expression cloning revealed that the CD100 receptor on lymphocytes is CD72, a negative regulator of B cell responsiveness. CD72 thus represents a novel class of semaphorin receptors. CD100 stimulation induced tyrosine dephosphorylation of CD72 and dissociation of SHP-1 from CD72. Our findings indicate that CD100 plays a critical role in immune responses by the novel mechanism of turning off negative signaling by CD72.

The class IV semaphorin CD100 plays nonredundant roles in the immune system: defective B and T cell activation in CD100-deficient mice

The class IV semaphorin CD100/Sema4D differentially utilizes two distinct receptors: plexin-B1 in nonlymphoid tissues, such as brain and kidney, and CD72 in lymphoid tissues. We have generated CD100-deficient mice and demonstrated that they have functional defects in their immune system, without apparent abnormalities in other tissues. The number of CD5(+) B-1 cells was considerably decreased in the mutant mice, whereas conventional B cells and T cells appeared to develop normally. In vitro proliferative responses and immunoglobulin production were reduced in CD100-deficient B cells. The humoral immune response against a T cell-dependent antigen and in vivo priming of T cells were also defective in the mutant mice. These results demonstrate nonredundant and essential roles of CD100-CD72 interactions in the immune system.

A case of dermatomyositis associated with mechanic's hand

A 67-year-old man was referred to the Department of Internal Medicine at Tokyo Medical University with interstitial pneumonia in July 1999. He presented with keratotic plaques on both palsm and on the ventral and lateral sides of his fingers. Erythematous keratosis was observed on the dosal aspect of his fingers and metatarsophalangeal (MP) joints. Edematous erythema was seen on the patient's chest, back, and the extensor surfaces of his arms. Electromyography revealed a myogenic pattern and an increased level of myogenic enzymes was found in the blood. Histological findings of the ventral sides of his fingers showed hyperkeratosis and parakeratosis of the dermal tissue and liquefaction degeneration of the basal layer at the papilla. Based on these findings, the patient was given a diagnosis of dermatomyositis associated with mechanic's hand. A systemic examination confirmed interstitial pneumonia and carcinoma of the duodenal papilla. Mechanic's hand is a type of dermatitis associated with myopathy first reported by Stahl et al. in patients with collagen disease. We report herein the first documented case of mechanic's hand in Asians.

Serial diffusion-weighted imaging in MELAS

Clinical features of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) resemble those of cerebral infarcts, but the pathogenesis of infarct-like lesions is not fully understood. To characterise these infarct-like lesions, we studied two patients with MELAS using diffusion-weighted (DWI) MRI before and after stroke-like episodes and measured the apparent diffusion coefficient (ADC) in the new infarct-like lesions. These gave high signal on DWI and had much higher ADC than normal-appearing regions. The ADC remained high even 30 days after a stroke-like episode then decreased in lesions, with or without abnormality as shown by conventional MRI. We speculate that early elevation of ADC in the acute or subacute phase reflects vasogenic rather than cytotoxic edema. The ADC of the lesions, which disappeared almost completely with clinical improvement, returned to normal levels, which may reflect tissue recovery without severe damage. To our knowledge, this is the first study of DWI in MELAS.

Gallyas-positive argyrophilic and ubiquitinated filamentous inclusions in rapidly progressive motor neuron disease: immunohistochemical and electron microscopic studies

In an autopsy case of sporadic rapidly progressive lower motor neuron disease (MND), Gallyas-positive argyrophilic and ubiquitinated filamentous intracytoplasmic inclusions were found in the neurons. Clinically, 7 months prior to death, a 68-year-old woman experienced a history of rapidly progressive muscle weakness of all four extremities and bulbar sign, without sensory and autonomic disturbance. Two months later, she became unable to stand or walk. Four months after onset, she needed respiratory support, and subsequently died due to cardiorespiratory arrest. Neuropathological examinations revealed neuronal loss and associated gliosis in the lower motor neurons, except for ocular motor nuclei, Clark's column, and accessory cuneate nucleus, and tract degeneration was observed in the middle root zone of the posterior column and spinocerebellar tract. No Bunina bodies or Lewy body-like hyaline inclusions were found in the anterior horns. Gallyaspositive argyrophilic filamentous inclusions were found in the lower motor neurons and in nerve cells of the Clark's column, intermediate zone, posterior horn and accessory cuneate nucleus. These were positive with anti-ubiquitin antibody but negative with anti-tau (tau-2 and AT8) and neurofilament antibodies. Electron microscopic examinations disclosed randomly arranged tubular-like filamentous profiles, with a diameter of 12-14 nm, sometimes with amorphous granules in the perikaryon. This is the first report on the Gallyas-positive argyrophilic and ubiquitinated filamentous inclusions in neurons in MND.

Mapping of a syndrome of X-linked thrombocytopenia with Thalassemia to band Xp11-12: further evidence of genetic heterogeneity of X-linked thrombocytopenia

X-linked thrombocytopenia with thalassemia (XLTT; Online Mendelian Inheritance in Man [OMIM] accession number 314050) is a rare disorder characterized by thrombocytopenia, platelet dysfunction, splenomegaly, reticulocytosis, and unbalanced hemoglobin chain synthesis. In a 4-generation family, the gene responsible for XLTT was mapped to the X chromosome, short arm, bands 11-12 (band Xp11-12). The maximum lod score possible in this family, 2.39, was obtained for markers DXS8054 and DXS1003, at a recombination fraction of 0. Recombination events observed for XLTT and markers DXS8080 and DXS8023 or DXS991 define a critical region that is less than or equal to 7.65 KcM and contains the gene responsible for the Wiskott-Aldrich syndrome (WAS; OMIM accession number 301000) and its allelic variant X-linked thrombocytopenia (XLT; OMIM accession number 313900). Manifestations of WAS include thrombocytopenia, eczema, and immunodeficiency. In WAS/XLT the platelets are usually small, and bleeding is proportional to the degree of thrombocytopenia. In contrast, in XLTT the platelet morphology is normal, and the bleeding time is disproportionately prolonged. In this study no alteration in the WAS gene was detected by Northern blot or Western blot analysis, flow cytometry, or complimentary DNA dideoxynucleotide fingerprinting or sequencing. As has been reported for WAS and some cases of XLT, almost total inactivation of the XLTT gene-bearing X chromosome was observed in granulocytes and peripheral blood mononuclear cells from 1 asymptomatic obligate carrier. The XLTT carrier previously found to have an elevated alpha:beta hemoglobin chain ratio had a skewed, but not clonal, X-inactivation pattern favoring activity of the abnormal allele. Clinical differences and results of the mutation analyses make it very unlikely that XLTT is another allelic variant of WAS/XLT and strongly suggest that X-linked thrombocytopenia mapping to band Xp11-12 is a genetically heterogeneous disorder.

Differential effect of antiallergic drugs on IgE-mediated cutaneous reaction in passively sensitized mice

We investigated the effect of several antiallergic agents on murine IgE-mediated biphasic cutaneous reaction. Mice were passively sensitized by an intravenous injection of monoclonal anti-dinitrophenol (anti-DNP) IgE antibody. Skin reaction was elicited by an epicutaneous challenge of dinitrofluorobenzene (DNFB) and occurred biphasically with immediate-phase response (IPR) and late-phase response (LPR) at 1 and 24 h, respectively. Classical histamine H1 receptor antagonists and some chemical mediator-release inhibitors, such as diphenhydramine and terfenadine, inhibited IPR, but not LPR. In contrast, leukotriene B(4) (LTB(4)) receptor antagonist (ONO-4057) inhibited LPR only. Antagonists for LTC(4), D(4), E(4) receptor (ONO-1078) and platelet-activating factor (PAF) receptor (Y-24180) significantly inhibited both IPR and LPR, similarly to prednisolone. We recently found that a third-phase inflammatory reaction with marked infiltration of eosinophils (named very-late-phase response; vLPR), which is supposed to be a more important reaction in allergic diseases, was induced, peaking at day 8 following IPR and LPR in this model. The effect of these drugs on the triphasic skin reaction can be scored based on efficacy against IPR / LPR / vLPR; +/+/+ (prednisolone, a PAF receptor antagonist Y-24180, cyclosporin A and FK-506), +/-/- (diphenhydramine), +/+/- (azelastine and LT receptor antagonist ONO-1078), and -/+/+ (an LTB(4) receptor antagonist ONO-4057). Thus the inhibitory effect on vLPR as well as LPR may relate to the inhibition of eosinophil function mediated by LTB(4) and PAF and/or T cells. These findings may provide the basis for a treatment modality using various antiallergic agents in allergic disease.

Efficacy of yeast phytase in improving phosphorus bioavailability in a corn-soybean meal-based diet for growing pigs

Crossbred barrows (n = 66; 6 wk old) were used in a 6-wk experiment to evaluate the efficacy of phytase from yeast or Aspergillus niger on performance, tibial characteristics, and serum inorganic P concentration. We also investigated the stability of these phytases in acidic solutions with pepsin, which simulated gastric conditions. Pigs were fed a P-adequate diet containing .34% nonphytate-P or a low-P diet containing .20% nonphytate-P. The low-P diet was supplemented with 0, 1,000, 2,000, or 4,000 phytase units (PU; the activity at optimal pH, i.e., pH 4.2 for yeast phytase and pH 5.5 for phytase from Aspergillus niger)/kg of yeast phytase, or 1,000 PU/kg phytase from Aspergillus niger. The graded level of yeast phytase linearly increased ADG (P = .047), tibial weight (P = .091), tibial density (P < .001), and P concentration in tibial cortex (P = .018). Aspergillus niger phytase also increased ADG (P = .022), serum inorganic P concentration (P < .001), tibial density (P = .007), and tibial P concentration (P = .025). The pigs given 1,000 PU/kg Aspergillus niger phytase showed greater ADG (P = .091), tibial density (P= .001), and tibial P concentration (P = .062) than those given 1,000 PU/kg yeast phytase. No measurements differed (P > .31) between the pigs given 1,000 PU/kg Aspergillus niger phytase and those given 4,000 PU/kg yeast phytase. These results suggested that yeast phytase improves bioavailability of P in the diet for growing pigs but the efficacy of yeast phytase is less than that of Aspergillus niger phytase. During incubation in acidic solutions with pepsin, yeast phytase (P < .001) lost more of its activity than Aspergillus niger phytase. This lesser stability of yeast phytase may be responsible for the poorer efficacy of yeast phytase than that of Aspergillus niger. In summary, supplementation of swine diets with yeast phytase is beneficial, but its efficacy is less than that of Aspergillus niger phytase.

Numerous conglomerate inclusions in slowly progressive familial amyotrophic lateral sclerosis with posterior column involvement

A 59-year-old woman with slow progression of the loss of motor function and predominant lower motor manifestation during a 14-year period showed familial amyotrophic lateral sclerosis (fALS) with posterior column involvement, neuropathologically. Conglomerate inclusions (CIs) were observed in the remaining neurons in various areas, including the spinal anterior horn, posterior horn, Clark's column, accessory cuneate nucleus, tegmental reticular formation, motor nucleus of the trigeminal nerve, nucleus of the facial nerve, hypoglossal nucleus, medial nucleus of the thalamus, dentate nucleus, and motor cortex (Betz cells). Immunohistochemically, it was newly identified that the CIs showed marked immunoreactions with antibodies to phosphorylated and non-phosphorylated neurofilaments and to 64, 120, and 200 kD neurofilaments. The CIs were partially immunoreactive with the anti-ubiquitin antibody, although they reacted only weakly (or not at all) with anti-Cu/Zn superoxide dismutase (SOD1) antibody. Ultrastructurally, the CIs were comprised of neurofilaments. These data suggest that this case might have been different from an example of fALS with Ile 113 Thr mutation in the SOD1 gene.

Biological characteristics and prognostic value of in vitro three-drug resistance to prednisolone, L-asparaginase, and vincristine in childhood acute lymphoblastic leukemia

The purpose of this study was to investigate the biological characteristics and prognostic value of in vitro three-drug resistance to prednisolone, L-asparaginase, and vincristine in childhood acute lymphoblastic leukemia (ALL). We carried out in vitro tests with a 4-day culture and a methyl-thiazol-tetrazolium assay on bone marrow samples from 209 children newly diagnosed with ALL. After testing the resistance of leukemic cells to 14 drugs, we classified the patients into two groups according to their sensitivity to three drugs (prednisolone, L-asparaginase, and vincristine) used in remission induction therapy. The three-drug resistant group (RR: sensitive to no drugs or to one drug) correlated with both short-term and long-term treatment failure. Three-year event-free survival (95% confidence interval) for the sensitive group (SS: sensitive to two or three drugs) was 0.813 (0.773-0.853) and that of the RR group was 0.616 (0.569-0.669) (P = 0.0001). Univariate analysis showed that Philadelphia-chromosome (Ph1) positivity and immunophenotype of mixed lineage were also prognostic factors in the 209 patients. The prognosis of the SS/RR drug resistance profile within 14 Ph1 patients was marginally significant (P = 0.062). Multivariate Cox regression analysis showed that Ph1 was an overwhelmingly adverse factor in event-free survival, with a relative hazard of 5.37 (2.57-11.21, P < 0.0001), followed by RR, with a relative hazard of 2.98 (1.69-5.25, P = 0.0001). Furthermore, we clarified the characteristics of the RR group by examination of the pattern of drug resistance to other drugs in comparison with the SS group. The leukemic cells of RR patients were more resistant than those of SS patients (P < 0.0001) to all the drugs tested, with resistance ratios of 1.6 to 13.1 (mean 3.4). In conclusion, in vitro three-drug resistance at the initial stage is an important independent predictor of treatment failure for both induction response and long-term outcome in childhood ALL.

Major metabolites of substance P degraded by spinal synaptic membranes antagonize the behavioral response to substance P in rats

Substance P (SP) was degraded by synaptic membranes of rat spinal cord. Cleavage products were separated by reversed phase high performance liquid chromatography and identified by amino acid composition analyses. Major products of SP were phenylalanine, SP(1-4), SP(1-6), SP(1-7), SP(10-11), and SP(8-9). Both the degradation of SP and the accumulation of the major cleavage products were strongly inhibited by a metal chelator, o-phenanthroline, and also by specific inhibitors of endopeptidase-24.11, thiorphan, and phosphoramidon. Thus, endopeptidase-24.11 plays a major role in SP degradation in the rat spinal cord. N-Terminal fragments, SP(1-7) and SP(1-4), detected after incubation with spinal synaptic membranes were examined in vivo for antagonism against the scratching, biting, and licking response induced by intrathecal (IT) injection of SP (3.0 nmol) in rats. When IT coadministered with SP, SP(1-7) and SP(1-4) produced a significant inhibition of behavioral response to SP with ED50 of 135.0 pmol and 6.2 nmol, respectively. These results suggest that the degradation of SP in the spinal cord is not only responsible for inactivation of parent peptide, but may also lead to the formation of N-terminal SP-fragments which are shown to display a novel physiological function.

Gallyas- and tau-positive glial structures in motor neuron disease with dementia

We have studied Gallyas- and tau-positive glial structures in three autopsied cases of motor neuron disease with dementia (MND-D). Gallyas-positive, tau-immunoreactive thread-like structures in the neuropil and crescent/coiled inclusions in the glial cells were mainly observed in the hippocampus, parahippocampal gyrus, and amygdaloid nucleus. Double staining using Gallyas staining and carbonic anhydrase 2 (CA2) immunohistochemistry revealed that some crescent/coiled inclusions occurred in the CA2-immunopositive cytoplasm of the oligodendroglia. Electron microscopic study with the Gallyas-Braak method revealed that the inclusion was a reticular, partly compact mass, containing 15 nm fibrils around round or oval nuclei. Since the regions where these structures appeared exhibited neuronal loss with gliosis, these data suggest that a cytoskeletal abnormality involving tau protein in glia might be associated with the degenerative process of MND-D.

Matrix interferences in the analysis of digested biological tissues with inductively coupled plasma-mass spectrometry

To investigate the physiological roles or toxicity of trace or toxic elements, multielement analysis of limited quantities of samples in the biological tissues is required. Inductively coupled plasma mass spectrometry (ICP-MS) suits this requirement, but spectral and nonspectral interferences are inevitable. We examined correction methods for the nonspectral interferences by analyzing signals of 21 elements in various concentrations of HNO3 as well as five major elements (Na, K, P, Ca, and Cl). Using internal standards, the interferences caused by the major elements were corrected, but the interferences caused by HNO3 were impossible to correct for elements with high ionization potentials. The analytical results using the standard addition method on 14 elements in standard reference materials and fresh brain tissues confirmed the accuracy of this method. Thus, we concluded that the standard addition method is useful to correct for the nonspectral interferences.

[Collecting duct carcinoma (Bellini duct carcinoma) of the kidney with tumor extension into the inferior vena cava]

We report a case of collecting duct carcinoma (Bellini duct carcinoma) of the left kidney accompanied with a tumor thrombus in the inferior vena cava and the lymph node metastasis. A 69-year-old male presented with gross hematuria and left flank dullness. Computed tomography revealed an isodensity tumor in the left kidney with tumor extension into the inferior vena cava and the regional lymph node swelling. The T1-weighted magnetic resonance image displayed a slightly heterogeneous low-intensity-mass. Renal angiography revealed a hypervascular tumor. We performed left radical nephrectomy with tumor thrombectomy and regional lymphadenectomy. Histopathological examination revealed a collecting duct carcinoma (pT3bN1M0V2a). Seven months after surgery, multiple metastates in bone and liver developed. Then we performed systemic chemotherapy consisting of methotrexate and cisplatin. However, the patient died from the carcinoma 10 months postoperatively.

Implications of marked fatty infiltration around and in the atrophic atrioventricular node in elderly patients with permanent pacemaker implantation for symptomatic sick sinus syndrome

The present study undertook an extensive analysis of the histopathological findings of the atrioventricular conduction system in 14 elderly patients treated with permanent pacemakers for sick sinus syndrome (SSS). Special attention was given to the lowest Wenckebach block points of atrioventricular conduction during rapid atrial pacing, and ventricular rate or duration of ventricular pause during chronic atrial fibrillation. An electrophysiological study (EPS) was conducted under sinus rhythm in 13 patients and under junctional escape rhythm in 1 patient. Three of the 14 cases showed a lower Wenckebach block point of 130 beats/min or less. Two of these 3 cases showed excessive fatty infiltration around the atrionodal junction area and into the atrophic atrioventricular node (AVN) itself. Of the 6 patients who had chronic atrial fibrillation after pacemaker implantation, 2 cases showed a slow ventricular response of less than 60 beats/min and/or a long ventricular pause of 3.3 s. One of the 2 cases showed a lower Wenckebach block point of 130 beats/min at the time of EPS. The other, who later progressed to idiopathic atriomegaly, also showed marked fatty infiltration around the AVN. This fatty lesion was closely associated with diffuse disruption of the muscular fibers connecting the atrophic AVN with the atrium. In addition, most of the remaining cases also had an atrophic AVN. In conclusion, a sparse or absent atrionodal connection and an atrophic AVN due to excessive fatty infiltration in the atrionodal transitional area should be investigated in atrioventricular conduction disturbances in the elderly with SSS.

Adenosine triphosphate-sensitive potassium channels are involved in insulin-mediated glucose transport in humans

We investigated the influence of treatment with nicorandil, a K-channel opener currently used for angina, on glucose homeostasis in patients with non-insulin-dependent diabetes mellitus (NIDDM) and coronary artery disease (CAD). Adenosine triphosphate (ATP)-sensitive K (K-ATP) channels are present in various tissues, including pancreatic B cells and skeletal muscle, and are the putative targets of this agent. Nine NIDDM patients with CAD and five healthy subjects participated in the study. Fasting plasma levels (mean+/-SEM) of glucose (144+/-11 to 180+/-22 mg/dL, P<.05) and insulin (5.8+/-1.6 to 7.0+/-1.8 microU/mL, P<.05) and hemoglobin A1c (7.54+/-0.47 to 8.11+/-0.55%, P<.01) increased significantly in nine NIDDM patients after treatment with nicorandil at a dose of 5 mg three times daily for 2 to 8 months. Glucose tolerance as examined by an identical meal test deteriorated (P<.001), but the insulin response did not change significantly. A washout of nicorandil for 1 to 4 months restored glucose tolerance almost to pretreatment levels in four patients. A 5- to 7-day trial of nicorandil (5 mg three times daily) in five healthy subjects resulted in a marginal to twofold increase in fasting plasma insulin, reflecting the progression of insulin resistance. In addition, three healthy subjects showed a substantial reduction in the glucose infusion rate (GIR) required in the euglycemic-hyperinsulinemic clamp study. Since the therapeutic dose of nicorandil did not affect pancreatic B-cell function but caused insulin resistance in both healthy and NIDDM subjects, we conclude that K-ATP channels play a regulatory role in insulin-mediated glucose transport in humans.

In utero methylmercury exposure differentially affects the activities of selenoenzymes in the fetal mouse brain

Pregnant ICR mice were subcutaneously injected with 0,5, or 3x3 mg Hg/kg of methylmercury (MeHg) on days 12,13, and 14(G12-14) of gestation and were sacrificed on G17. Activity of selenoenzymes, including glutathione peroxidase (GPx) and 5'- or 5-iodothyronine deiodinases (5'-DI, 5-DI), was determined in fetal brain and placenta. MeHg did not affect the concentration of Se in these tissues, while it significantly inhibited the activity of GPx in the fetal brain and placenta, but not in the maternal brain. Although the levels of thyroid hormones in the maternal and fetal plasma were not affected by MeHg, 5-DI decreased and 5'-DI increased in the fetal brain, as if they had responded to hypothyroidism. Because the level of T4 in the fetal plasma was not affected by MeHg, these changes in enzymatic activities may result in a harmful excess of T3 in the fetal brain. In addition, 5-DI activity was increased in the placenta of MeHg-treated mice. These effects of prenatal MeHg exposure on fetal and placental DIs differed from those of dietary-induced Se deficiency, where the activities of DIs were decreased or not affected. Further evaluation of the effect of MeHg on selenoenzymes, especially 5-DIs, is warranted.

Torsades de pointes in a case of hypertrophic cardiomyopathy with special reference to the pathologic findings of the heart including the conduction system

A clinicopathologic study was performed in a 77-year-old female with hypertrophic cardiomyopathy who had experienced recurrent syncopal attacks due to Torsades de Pointes (TdP) following QT prolongation and atrioventricular block. She died suddenly two years later while eating dinner. Pathologic findings of the heart showed a dilated and hypertrophied left ventricle. The heart weighed 550 g. There were two foci of localized endocardial fibroelastosis (EFE) beneath the aortic valve, one with a size of 3.5 x 3.5 cm, and the other (2 x 1 cm) located on the upper ventricular septum. Histologic findings showed hypertrophy and disarray in the left ventricular myocardium. The conduction system using serial sectioning revealed remarkable bilateral bundle branch fibrosis and hypertrophied Purkinje fibers in the left bundle branch adjacent to the EFE on the ventricular septum. These findings were thought to be related to the occurrence of TdP.

The effect of prenatal methylmercury exposure on the GSH level and lipid peroxidation in the fetal brain and placenta of mice

Effect of prenatal exposure to methylmercury (MeHg) on the glutathione (GSH) levels and lipid peroxidation in the fetal brain was examined. Pregnant ICR mice were injected with 3 mgHg/kg of MeHg on gestational day 12, 13 and 14 (G12-14). On the G14 or G17, the fetal brains were removed and their GSH levels and thiobarbituric acid-reactive substances (TBARS) levels were determined. On the G17, GSH level of MeHg-treated fetal brain was significantly higher than that of the control brain; the TBARS level showed the similar trend but the difference was not significant. These results indicated that the prenatal MeHg treatment disturbed the normal GSH level in the fetal brain and warranted further investigation on the significance of this GSH perturbation.

Separation of selenium-containing proteins in human and mouse plasma using tandem high-performance liquid chromatography columns coupled with inductively coupled plasma-mass spectrometry

An analytical method that uses two different high-performance liquid chromatography (HPLC) columns in tandem has been developed that separates three major selenium-containing proteins (albumin, glutathione peroxidase, and selenoprotein P) found in human blood plasma. The first column was a heparin affinity column and the second was a gel filtration column whose outlet was directly connected to an inductively coupled plasma-mass spectrometer. The method successfully separated plasma selenium into the three selenium-containing proteins and revealed the preferential retention of selenium in the form of selenoprotein P in a selenium-deficient human and in selenium-deficient mice. Our results also confirm the results of previous studies that showed a preference for supplemented selenium to be taken up as selenoprotein P in rats. Advantages of the tandem column method are that it allows rapid and convenient analyses of the distribution of plasma selenium, and that it is suitable for stable isotope tracer studies and metal interaction studies.

Inhibitory mechanisms of glycoprotein fraction derived from Miscanthus sinensis for the immediate phase response of an IgE-mediated cutaneous reaction

We investigated the inhibitory effect of the glycoprotein fraction (fraction 2) extracted from Miscanthus sinensi ANDERSSON (M. sinensis) on biphasic cutaneous reactions in mice passively sensitized with IgE. Biphasic skin reactions with peak responses at 1 (IPR, immediate phase reaction) and 24 h (LPR, late phase reaction) were caused by passive sensitization with an anti-dinitrophenol IgE monoclonal antibody (anti-DNP IgE mAb) followed by an epicutaneous challenge of 0.1% dinitrofluorobenzene (DNFB) in 100% ethanol. Intraperitoneal injection of fraction 2 before the DNFB challenge significantly inhibited the biphasic ear swelling response in passively sensitized mice in a dose-dependent manner (1-30 mg/kg). We also found that fraction 2 was effective at inhibiting the vascular permeability in mouse ear induced by an injection of compound 48/80, histamine or serotonin. In addition, fraction 2 inhibited scratching behavior as well as ear edema observed within 2 h after DNFB challenge. Marked inhibition was observed in both passively sensitized and non-sensitized mice. The locomotor activity of mice was also reduced by the administration of fraction 2 as well as by diphenhydramine. These results suggest that the inhibitory effect of glycoprotein fraction 2 of M. sinensis on an IgE-mediated allergic inflammatory reaction is due to the protection of mediator-induced vascular permeability and that in addition to the inhibition of an inflammatory reaction, a sedative action is responsible for the inhibition of allergy-induced scratching responses.

Spinal actions of GR73632, a novel tachykinin NK1 receptor agonist

Behavioral characterization of GR73632, a newly synthesized tachykinin NK1 receptor agonist, was examined in mice. Intrathecal (IT) injection of GR73632 in the spinal subarachnoid space of mice elicited a dose-dependent behavioral syndrome, consisting of scratching, biting and licking. The time course of the response to GR73632 was almost similar to that of substance P. GR73632 evoked much more licking and biting than did substance P, that in turn caused less scratching. GR73632 was approximately 200-fold more potent than substance P in inducing the characteristic behavioral response. The GR73632-induced behavioral response was inhibited by IT co-administration of CP-96,345, a non-peptide NK1 receptor antagonist, but not its inactive enantiomer CP-96,344. CP-96,345, co-injected IT with substance P, also inhibited the behavioral response to substance P. These results demonstrate that the scratching, biting and licking response induced by IT GR73632 may be mediated by the NK1 receptor in the spinal cord. These findings suggest that GR73632 may be useful as a tachykinin NK1 receptor agonist and also for evaluating spinal pharmacological activities of NK1 receptor antagonists.

In utero exposure to methylmercury and Se deficiency converge on the neurobehavioral outcome in mice

Pregnant female ICR mice, maintained on torula-based diets containing various amounts of Se (0.02, 0.05, or 0.4 mg/kg diet), were given methyl-mercury (MeHg; 0, 5, or 9 mg Hg/kg in total) on the 12-14th days of gestation. The neurobehavioral function of the offspring born to these dams was evaluated with respect to reflex and motor development, thermal preference, and open-field activity. Se deficiency per se as well as exposure to MeHg exerted additive or synergistic effects on the neurobehavioral functions examined. The group of mice most affected was the group given the lowest amount of Se and the highest dose of MeHg. Thus, the neurobehavioral outcome of in utero MeHg exposure and Se deficiency converged. Although the dietary level of Se did not affect the Hg concentration in the fetal brain, the Se concentration and the activity of glutathione peroxidase, a selenoenzyme, were severely depressed by MeHg in the neural tissue. The possibility that functional Se deficiency by MeHg exposure partly accounts for the neurobehavioral toxicity of MeHg is discussed.

Slowly progressive L-DOPA nonresponsive pure akinesia due to nigropallidal degeneration: a clinicopathological case study

We report an autopsy case of a 51-year old man who showed slowly progressive pure akinesia: freezing phenomenon and festination during 21 years of illness without tremor, rigidity, upward gaze palsy, bradykinesia and dementia, which were not responded to L-DOPA clinically. Neuropathological findings revealed the circumscribed regions in the substantia nigra and middle portion of the internal globus pallidus (GPi), without neurofibrillary tangles, neuropil threads, and glial fibrillary tangles. So this case was clearly distinguished with progressive nuclear palsy and pallidonigroluisian atrophy. It was first reported to describe that L-DOPA nonresponsive pure akinesia can arise from nigopallidal atrophy.

WISP genes are members of the connective tissue growth factor family that are up-regulated in wnt-1-transformed cells and aberrantly expressed in human colon tumors

Wnt family members are critical to many developmental processes, and components of the Wnt signaling pathway have been linked to tumorigenesis in familial and sporadic colon carcinomas. Here we report the identification of two genes, WISP-1 and WISP-2, that are up-regulated in the mouse mammary epithelial cell line C57MG transformed by Wnt-1, but not by Wnt-4. Together with a third related gene, WISP-3, these proteins define a subfamily of the connective tissue growth factor family. Two distinct systems demonstrated WISP induction to be associated with the expression of Wnt-1. These included (i) C57MG cells infected with a Wnt-1 retroviral vector or expressing Wnt-1 under the control of a tetracyline repressible promoter, and (ii) Wnt-1 transgenic mice. The WISP-1 gene was localized to human chromosome 8q24.1-8q24.3. WISP-1 genomic DNA was amplified in colon cancer cell lines and in human colon tumors and its RNA overexpressed (2- to >30-fold) in 84% of the tumors examined compared with patient-matched normal mucosa. WISP-3 mapped to chromosome 6q22-6q23 and also was overexpressed (4- to >40-fold) in 63% of the colon tumors analyzed. In contrast, WISP-2 mapped to human chromosome 20q12-20q13 and its DNA was amplified, but RNA expression was reduced (2- to >30-fold) in 79% of the tumors. These results suggest that the WISP genes may be downstream of Wnt-1 signaling and that aberrant levels of WISP expression in colon cancer may play a role in colon tumorigenesis.

[Comparison of clinical pictures of mitochondrial encephalomyopathy with tRNA(Leu(UUR)) mutation in 3243 with that in 3254]

We compared clinical pictures of a case of mitochondrial encephalomyopathy with tRNA(Leu(UUR)) point mutation at nucleotide position 3254 of mitochondrial DNA with those at position 3243. The mutation 3254 was a 19-year-old male patient with cardiomyopathy accompanied with muscle atrophy. The first mutant 3243 was a 31-year-old female patient showing clinical features of MELAS and endocrinological abnormalities. The second 3243 mutant was a 27-year-old male patient who had an external ophthalmoplegia and slight mental decline. In all cases, muscle biopsy specimen showed ragged red fibers and strongly SDH-reactive blood vessels, but their limb weakness were unremarkable. These results suggest that tRNA(Leu(UUR)) point mutation 3254 exhibits similar clinical phenotypes as those observed in 3243 mutant.

[Vocalization response used for evaluation of pain-related behavior in guinea pigs]

In general, pain has been defined as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage", and hence pain is a subjective and emotional experience for each individual. For this reason, it is difficult to study pain in nonverbal animals. However, painful stimuli (noxious stimuli) can cause both a simple and an overt emotional behavior such as self-defense reaction and vocalization in animals. Therefore, we are able to measure these behaviors as nonverbal communication of pain. The vocalization responses is the natural nociceptive reaction of conscious animals and prelingual children. In the present overview, we described the methodology for objective assessment of guinea pig's vocalization response to arterial algogenics and its characteristics.

Second primary rhabdomyosarcomas in patients with bilateral retinoblastoma: a clinicopathologic and immunohistochemical study

We reviewed six cases of rhabdomyosarcoma as a rare second primary malignancy in children with bilateral retinoblastoma after irradiation treatment. The patients comprised four females and two males (age range 1 year 4 months-7 years 11 months). Second tumors arose in the temporal muscle inside or close to the previously irradiated fields. All the children were alive and well 24-72 months after diagnosis. Microscopic examination showed proliferation of closely packed, small round cells with scanty cytoplasm, coarse nuclear chromatin, and increased mitotic activity without a myxoid background nor obvious alveolar architecture. The most characteristic feature was the presence of rosette-like structures in four tumors. Immunoreactivity for many skeletal muscle markers was evident, including desmin (six of six), muscle-specific actin (HHF35) (six of six), sarcomeric actin (six of six), myogenin (six of six), vimentin (six of six), and myoglobin (three of six). On reverse transcriptase-polymerase chain reaction examination, three second tumors lacked specific chimeric transcripts for alveolar rhabdomyosarcoma and Ewing's sarcoma. Unexpectedly, variable reactivity for neurofilament (150 kd) was identified in six of six second tumors as well as 15 of 20 sporadic primary rhabdomyosarcomas (75%) examined as controls, the result being confirmed by Western blot analysis. In addition, staining for retinoblastoma-susceptibility gene protein was negative in all second tumors, in contrast to positivity in 14 of 17 sporadic primary tumors (82%). This finding suggests that retinoblastoma-susceptibility gene abnormalities could be associated with the development of second primary rhabdomyosarcoma. We consider that knowledge of the occurrence of rhabdomyosarcoma and appropriate immunohistochemical study are helpful for avoiding a misdiagnosis of recurrent retinoblastoma or Ewing's sarcoma when encountering patients with a history of bilateral retinoblastoma who developed second small round cell neoplasms.

Functional analysis of peripheral blood B cells in patients with X-linked agammaglobulinemia

X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disease caused by mutations of Bruton tyrosine kinase (Btk); Btk plays an essential role in the development of mature B cells. However, small numbers of B cells ("leaky B cells") are present in the peripheral blood of most XLA patients. In this study, we analyzed the function of these leaky B cells obtained from XLA patients. Enough numbers of B cells were available for analysis from five of nine XLA patients originally screened. Sequence analysis revealed missense mutations of Btk in four of the five XLA patients. No mutation was found in the coding region of Btk in one patient. Western blotting and/or flow cytometric analysis failed to detect Btk protein in all five patients. B cells isolated from peripheral blood of these XLA patients were CD5-, CD20+, CD19+, and CD21-. If stimulated with anti-CD40 and IL-4, XLA B cells proliferated normally and produced significant amounts of IgE. Anti-CD40 stimulation of XLA B cells resulted in normal expression of CD23. In addition, three of the five XLA patients studied were immunized with bacteriophage phiX174 and produced low but detectable levels of antiphage-specific Ab. Similarly, X-linked immunodeficiency mice, which carry a missense mutation in Btk, produced substantial amounts of antiphage Ab. These results indicate that CD40 signaling is intact in B cells lacking demonstrable Btk, and that leaky B cells in XLA patients can proliferate, undergo isotype switching, and differentiate into specific Ab-producing cells.

Collagen induces tyrosine phosphorylation of Wiskott-Aldrich syndrome protein in human platelets

Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) are caused by mutations of the WAS protein (WASP) gene. All hematopoietic stem cell-derived lineages, including platelets, express WASP. Platelets from WAS patients are smaller than their normal counterparts and defects in platelet aggregation and actin polymerization have been reported. To determine if WASP is important for normal platelet function, we examined its role in signal transduction. We found that collagen but not thrombopoietin or thrombin induces a rapid and robust increase in tyrosine phosphorylation of platelet-associated WASP. Collagen-induced tyrosine phosphorylation of WASP was inhibited by cytochalasin D and wortmannin, respectively, suggesting that actin polymerization and phosphatidylinositol 3-kinase (PI3-kinase) play a role in the induction of tyrosine phosphorylation of WASP. Binding of glutathion S-transferase (GST)-Grb2 to WASP was seen in the lysate of resting platelets. The binding was reduced when lysates from collagen-stimulated platelets were incubated with GST-Grb2, suggesting that tyrosine phosphorylation of WASP may directly or indirectly modulate the adapter function of WASP. Although thrombin- and thrombopoietin-induced increase in tyrosine phosphorylation of WASP is negligible or marginal, WASP from thrombin-activated platelets became incorporated into the Triton X-100-insoluble 10, 000g sedimentable residue in an aggregation-dependent manner, suggesting that it may have a regulatory role in platelet cytoskeletal processes during aggregation. Lastly, we found that WASP is cleaved in response to activation of calpain, a protease that may have a role in postaggregation signaling processes. Our data suggest that collagen specifically induces an increase in tyrosine phosphorylation of WASP and that WASP is involved in signaling during thrombin-induced aggregation by its redistribution to the cytoskeleton and its cleavage during aggregation.

High incidence of diabetic nephropathy in early-onset Japanese NIDDM patients. Risk analysis

OBJECTIVE

Because early-onset Japanese NIDDM patients (diagnosed before age 30 years) can develop diabetic end-stage renal failure (ESRF) in their thirties, this study was performed to elucidate the incidence and determinants for the development of diabetic nephropathy.

RESEARCH DESIGN AND METHODS

The incidence of diabetic nephropathy and its relationship to baseline characteristics and long-term metabolic control were determined in 426 early-onset Japanese NIDDM patients who were followed for a mean of 6.8 years.

RESULTS

Of these 426 patients, 41 developed diabetic nephropathy manifested by persistent proteinuria (incidence rate [95%CI]/1,000 person-years; 14.1 [10.4-19.1]). Among patients whose mean HbA1c (measured by a high-performance chromatography method that is standardized and comparable to the one used in the Diabetes Control and Complications Trial study) was around 7% or less, few developed nephropathy. The incidence of nephropathy increased with increasing mean HbA1c level in a dose-dependent manner (chi 2 trend = 49.9, P < 0.0001). Diastolic blood pressure and duration of diabetes at entry had significant predictive effects independent of metabolic control.

CONCLUSIONS

The incidence rate of diabetic nephropathy in early-onset Japanese NIDDM patients is potentially high, similar to or higher than that in Pima Indian NIDDM or Caucasian IDDM patients of comparable age. Diabetic nephropathy in NIDDM patients aged in their thirties or forties is likely to be an early feature that leads to ESRF, and this would contribute to the marked increase in the number of new patients with diabetic ESRF in Japan. NIDDM is a serious disease if near-normal glycemia is not achieved.

Nonasthmatic case of Churg-Strauss syndrome with rapidly progressive glomerulonephritis

A 61-year-old man developed mononeuritis multiplex accompanied by eosinophilia in 1993. Approximately 3 years later, acute renal dysfunction, a subendocardial tumor, and a high peripheral anti-neutrophil cytoplasmic antibody titer were also detected. Renal biopsy revealed glomerular crescents and interstitial infiltration of eosinophils, so allergic granulomatosis and angiitis was diagnosed. These clinical abnormalities regressed with steroid therapy. He had no history of asthma. This was therefore considered to be an atypical form of Churg-Strauss syndrome with rapidly progressive glomerulonephritis.

Effects of mild chronic heat exposure on the concentrations of thiobarbituric acid reactive substances, glutathione, and selenium, and glutathione peroxidase activity in the mouse liver

To determine whether mild and chronic heat stress leads to oxidative stress and to differentiate such effects of different exposure periods, we kept male ICR-mice at an ambient temperature of either 35 degrees C or 25 degrees C for 6 hours, 3 days, or 7 days and measured the concentrations of thiobarbituric acid reactive substances (TBARS), glutathione (GSH), selenium (Se), and glutathione peroxidase (GSH-Px) activities in the liver. Since the food consumption of the heat-exposed group was only half that of the control, we prepared pair-fed groups, which were kept at 25 degrees C and whose food consumption were limited to those of the heat-exposed group for the 3-day and the 7-day exposure. TBARS concentrations of the liver was significantly higher in the heat group than the control after the 3-day exposure, while there was no significant difference among the groups after the 7-day exposure. There was no significant difference in GSH concentrations between the heat-exposed group and the control after the 7-day exposure, when the GSH concentration of the pair-fed group was significantly lower than that of the control. Hepatic cytosolic Se GSH-Px activity in the heat group was significantly less than that in the control group after the 6-hour exposure and it tended to be lower in the heat group than that of the control group after the 7-day exposure, while there was no difference in the total GSH-Px activity among the three groups. Our results showed that mild and chronic heat exposure may cause oxidative damage to organisms and that GSH-related anti-oxidative systems would play an important role to defensive reaction.

Argyrophilic structures stimulate glial reactions in neurofibrillary tangles and senile plaques

Neurofibrillary tangles (NFT) and senile plaques (SP) contain various pathological structures, and the majority of these pathological structures are argyrophilic. To investigate the glial reactions of the argyrophilic substance, we performed immunohistochemistry for microglia or for astroglia after Gallyas-Braak staining, which is one of the most sensitive silver impregnation techniques detecting argyrophilic structures in NFT and SP. We found that extracellular argyrophilic structures in NFT and SP showed glial reactions, and we observed reactive microglia in the center of NFT and SP in contrast to astroglia, which were situated in the periphery. These findings suggest that the exposed argyrophilic components in the extracellular space stimulate both glial reactions, but that there is a striking difference in localization between microglia and astroglia.

Effect of spikelets of Miscanthus sinensis on IgE-mediated biphasic cutaneous reaction in mice

The effect of spikelets of Miscanthus sinensis Andersson (M. sinensis) on IgE-mediated biphasic cutaneous reactions was investigated in BALB/c mice. Mice were passively sensitized by an intravenous (i.v.) injection of monoclonal antidinitrophenol IgE antibody (anti-DNP IgE mAb), or actively by an intraperitoneal (i.p.) injection of DNP-derivatized ovalbumin (DNP-OVA) plus aluminium hydroxide gel (Alum) as an adjuvant. Skin reactions were elicited by an epicutaneous challenge of dinitrofluorobenzene (DNFB) and occurred biphasically with peak responses at 1 and 24 h in both animal models. The administrations of a nondialysable water extract of M. sinensis within 2 h before or after DNFB challenge via oral or i.p. route significantly inhibited the biphasic cutaneous reactions in passively and actively sensitized mice. The inhibitory effect was much stronger than those of a glucocorticoid, prednisolone, and histamine release inhibitor, amlexanox, as positive controls. The active component(s) was predominantly located in the glycoprotein fraction by gel chromatography. In the ears of DNFB-challenged mice, this fraction suppressed the accumulation of inflammatory cells, including mast cells and neutrophils/macrophages. In addition, the biphasic ear swelling was also improved by an administration of the glycoprotein fraction 24 h before active sensitization. These findings indicate that the glycoprotein fraction of M. sinensis was able to inhibit not only the IgE-mediated allergic inflammatory reaction but also the IgE formation. Thus, this fraction may be a useful antiallergic therapy.

Carbon tetrachloride does not induce micronucleus in either mouse bone marrow or peripheral blood

We performed mouse bone marrow and peripheral blood micronucleus tests on carbon tetrachloride (CCl4). In the bone marrow assay, bone marrow cells were collected once after 24 h and twice, with a 24-h interval at a dose of 500, 1000 and 2000 mg/kg. In the peripheral blood assay, blood samples were collected 0, 24, 48 and 72 h after a single intraperitoneal injection at a dose of 1000, 2000 and 3000 mg/kg. As a result, micronucleated polychromatic erythrocytes (MNPCEs) were observed neither in the bone marrow assay nor the peripheral blood assay. We concluded that CCl4 does not induce chromosomal aberrations in the mouse bone marrow cells under these experimental conditions.

Deficiency of selenium enhances the K+-induced release of dopamine in the striatum of mice

To determine whether a selenium (Se) deficiency in the brain leads to a functional change in dopaminergic transmission in the striatum, in vivo microdialysis was conducted in mice fed a low-Se diet. After 11-13 weeks of the diet regimen, the activity of glutathione peroxidase (GPx) in the Se-deficient brain was reduced to 60% of the control brain. A high K+ perfusion (100 mM) increased the level of dopamine in the dialysate to 67 +/- 16 times the basal level; the increase was significantly greater than that observed in the control group (28 +/- 4 times). Such a between-group difference was not observed after 4-5 weeks of the Se-diet. These results indicated that prolonged Se deficiency altered the function of striatal dopaminergic neurons in mice. A possible contribution of enhanced oxidative stress due to the reduced GPx activity is discussed.

Decrease of neurons in the medullary arcuate nucleus of multiple system atrophy: quantitative comparison with Parkinson's disease and amyotrophic lateral sclerosis

The physiological functions of the medullary arcuate nucleus are supposed to be involved in autonomic cardioventilatory regulation, but neuropathological studies on neurodegenerative diseases have rarely reported about the arcuate nucleus. We quantitatively examined the neuronal density of the arcuate nucleus in patients with multiple system atrophy (MSA, n = 3), Parkinson's disease (PD, n = 3), amyotrophic lateral sclerosis (ALS, n = 2), and control subjects (n = 6), and statistically compared the findings in each group. Although the neuronal densities in PD and ALS patients were not different from that in the controls, MSA patients showed a marked depletion of neurons in the arcuate nucleus. The neuronal density (/mm2, mean +/- SEM) in the arcuate nucleus was 9.27 +/- 10.4 in MSA, and was significantly decreased (P < 0.05; Wilcoxon test), compared with that in control subjects (87.1 +/- 12.2). These results suggest that the lesioned arcuate nucleus is related to the pathogenesis of dysatonomia in MSA.

Wiskott-Aldrich syndrome/X-linked thrombocytopenia: WASP gene mutations, protein expression, and phenotype

Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT), caused by mutations of the WAS protein (WASP) gene, represent different phenotypes of the same disease. To demonstrate a phenotype/genotype correlation, we determined WASP gene mutations in 48 unrelated WAS families. Mutations included missense (20 families) and nonsense (eight) mutations located mostly in exons 1 to 4, and splice-site mutations (seven) and deletions and insertions (13) located preferentially in exons 7 to 11. Both genomic DNA and cDNA were sequenced and WASP expression was measured in cell lysates using peptide-specific rabbit anti-WASP antibodies. WASP was expressed in hematopoietic cell lines including bone marrow-derived CD34+ cells. Missense mutations located in exons 1 to 3 caused mild disease in all but one family and permitted WASP expression, although frequently at decreased concentration. Missense mutations affecting exon 4 were associated with classic WAS and, with one exception, barely detectable WASP. Nonsense mutations caused classic WAS and lack of protein. Insertions, deletions, and splice-site mutations resulted in classic WAS and absent, unstable, truncated, or multiply spliced protein. Using affinity precipitation, WASP was found to bind to Src SH3-containing proteins Fyn, Lck, PLC-gamma, and Grb2, and mutated WASP, if expressed, was able to bind to Fyn-glutathione S-transferase (GST) fusion protein. We conclude that missense mutations affecting the PH domain (exons 1 to 3) of WASP inhibit less important functions of the protein and result in a mild phenotype, and that missense mutations affecting exon 4 and complex mutations affecting the 3' portion of WASP interfere with crucial functions of the protein and cause classic WAS.

Tissue-specific modification of selenium concentration by acute and chronic dexamethasone administration in mice

Several clinical reports have shown changes in plasma Se concentration with corticosteroid treatments, but the results have been inconsistent. Few experimental studies have been done on this subject. In the present study the effect of dexamethasone (DEX) treatment on Se concentrations and activities of Se-dependent glutathione peroxidase (EC 1.11.1.9; SeGPx) were examined in adult male ICR mice. In the first experiment, DEX was given via drinking water containing 5 or 50 mg DEX/l. At 1 or 3 weeks of DEX treatment, mice were dissected and the Se concentrations as well as SeGPx activities in various tissues, including plasma, were determined. At 1 week the DEX-treated groups had significantly lower hepatic Se concentrations and significantly higher plasma and cerebral concentrations than the control group. The DEX-treated groups showed lower SeGPx activities in the hepatic cytosol and higher SeGPx activities in the plasma than the saline (9 g NaCl/l)-treated group, in parallel with the changes in Se concentrations. At 3 weeks, neither hepatic nor plasma Se concentrations showed a significant change. In the second experiment, mice were injected subcutaneously with DEX and, thereafter, mice were food-deprived. The DEX-injected groups had higher plasma Se concentrations. A similar finding was obtained also when the DEX- or saline-injected mice were not food-deprived. Thus, the difference between the DEX-treated and control groups was possibly caused by redistribution of tissue Se. These results suggested that the effects of DEX on Se concentrations were tissue dependent and that the higher plasma Se observed in DEX-treated groups might be explained by the release of tissue Se into plasma as plasma SeGPx.