Idiopathic severe pulmonary hypertension in an infant with pulmonary infection

We report a 5-month-old infant who showed typical echocardiographic findings of primary pulmonary hypertension without the typical histopathological findings and who recovered from severe pulmonary hypertension. Histopathological findings revealed mild thickening of small pulmonary arteries and activated macrophages in the lung. Some cases with idiopathic severe pulmonary hypertension in infants are associated with pulmonary infection.

Adhesion/decalcification mechanisms of acid interactions with human hard tissues

In order to study adhesion/decalcification mechanisms of acid interactions with human hard tissues such as bones and teeth, the chemical interaction of five carboxylic acids (acetic, citric, lactic, maleic, and oxalic) and two inorganic acids (hydrochloric and nitric) with enamel and two synthetic hydroxyapatite (HAp) powders with, respectively, a high and a low crystallinity were analyzed using X-ray photoelectron spectroscopy (XPS), atomic absorption spectrophotometry (AAS), and spectrophotometry (S). X-ray diffraction revealed that the crystallinity of the highly crystallized HAp was considerably higher than that of enamel while the crystallinity of the poorly crystallized HAp was similar to that of dentin and bone. XPS of acid-treated enamel demonstrated for all carboxylic acids ionic bonding to calcium of HAp. AAS and S showed for both HAps that all carboxylic and inorganic acids except oxalic acid extracted Ca significantly more than P, leading to a Ca/P ratio close to that of synthetic HAp (2.16 w/w). Oxalic acid extracted hardly any Ca, but substantially more P, leading to a significantly smaller Ca/P ratio than that of HAp. AAS showed that the calcium salt of oxalic acid hardly could be dissolved, whereas the calcium salts of all the other acids were very soluble in their respective acid solution. These results confirm the adhesion/decalcification concept (AD-concept) previously advanced. Depending on the dissolution rate of the respective calcium salts, acids either adhere to or decalcify apatitic substrates. It is concluded that the AD-concept that originally dictated the interaction of carboxylic acids with human hard tissues can be extended to inorganic acids, such as hydrochloric and nitric acid. Furthermore, HAp crystallinity was found not to affect the adhesion/decalcification behavior of acids when interacting with apatitic substrates, so that the AD-concept can be applied to all human hard tissues with varying HAp crystallinity.

Expression of glial cell line-derived neurotrophic factor induced by transient forebrain ischemia in rats

This study examined the expression of glial cell line-derived neurotrophic factor (GDNF) mRNA and the cellular localization of GDNF production in rats subjected to transient forebrain ischemia induced by four-vessel occlusion. Transient forebrain ischemia induced GDNF mRNA expression in the hippocampus from 3 h to 3 days after the ischemic episode, with peak expression at 6 h. The GDNF mRNA increase in the cerebral cortex was similar to that in the hippocampus, whereas no increase in GDNF mRNA was observed in the striatum and brainstem. Western blot analysis showed that GDNF in the hippocampal CA1 region was increased slightly from 3 to 24 h after the ischemia, and then subsequently declined to below the baseline level. In the hippocampus, GDNF was evenly produced in pyramidal neurons of both sham-operated rats and normal rats, as determined by immunohistochemistry. Interestingly, we found that ischemia-induced reactive astrocytes, as well as surviving neurons, produced GDNF in 3-7 days after the ischemia. On the other hand, in other regions, such as the cerebral cortex, striatum, and brainstem, there was no change in GDNF-positive cells secondary to ischemia. These findings suggest that expression of GDNF mRNA is regulated in part via ischemia-induced neuronal degeneration. They also suggest that ischemia-induced reactive astrocytes may produce GDNF to protect against neuronal death. Therefore, GDNF may play an important role in ischemia-induced neuronal death in the brain.

[Cellular and molecular pharmacological studies on membrane receptor-signaling and stress-responses in the brain]

Studies on the cellular and molecular mechanism of neurotransmitter receptor-signaling and of neuronal and glial cell responses to stresses seem to be important to elucidate the action mechanism of centrally-acting drugs and to develop novel therapeutics against several diseases in the brain. The present review shows our findings with regard to the membrane receptor-signaling mechanism including serotonin, noradrenaline, glutamate receptors, ion channels, G-proteins, protein kinases and drug actions in Xenopus oocytes injected with rat brain mRNA, NG108-15 cells and brain membranes. Regarding the results of studies on the inter- and intra-cellular mechanism of neurons and glial cells against cerebral ischemia/hypoxia, we review the involvement of a transcription factor NF-kappa B in LPS-elicited inducible NO synthase (iNOS) expression in rat astroglial cells. Then we describe possible involvement of: 1) ADP-ribosylation/nitrosylation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 2) decrease in mitochondrial membrane potential, release of caspase-3 from mitochondria and degradation of the inhibitor of caspase-activated DNase by activated caspase in NO-induced neuronal apoptosis. We observed that hypoxia results in expression of a molecular chaperon such as protein disulfide isomerase (PDI) and HSP70 in astroglial cells. Our recent findings indicate that overexpression of PDI in the rat hippocampus (in vivo) and in neuroblastoma SK-N-MC cells (in vitro) significantly suppress the hypoxia-induced neuronal death. From physiological/pathophysiological and pharmacological aspects, we review the importance of studies on the cellular and molecular mechanism of membrane receptor-signaling and of stress-responses in the brain to identify functional roles of neuro-glial- as well as neuro-neuronal interaction in the brain.

R133C and R168X mutations in Japanese Rett syndrome patients: a caution for misdiagnosis

Rett syndrome is a neurodevelopmental disorder characterized by regression of motor and mental abilities in females after a period of normal development. The gene, MECP2, has been reported to be responsible for Rett syndrome. Here, we report the cases who were at first misdiagnosed as having homozygous mutations, and later corrected as heterozygous ones. We analyzed the MECP2 gene in three sporadic Japanese patients with Rett syndrome. Direct sequencing by using a primer set that was originally used in the first report of MECP2 mutation suggested two types of homozygous mutations (R133C and R168X). Previous reports of these mutations with heterozygous status, as well as the general nature of dominant inheritance in Rett syndrome females and lethality in hemizygous males, urged us to confirm the homozygosity of these mutations. By using a newly designed PCR primer, we found that these mutations actually occurred heterozygously in these patients. Sequence analyses of PCR products suggested that a C/T polymorphism found upstream of these mutations caused the preferential PCR amplification of the mutated alleles. These results recommend paying attention to biased PCR amplification that may lead to misjudgment of the result for mutational analysis of the MECP2 gene.

Functional analyses of MeCP2 mutations associated with Rett syndrome using transient expression systems

Rett syndrome, an X-linked neurodevelopmental disorder, is a major cause of mental retardation in females. Recent genetic analyses have revealed that mutations in the methyl-CpG-binding protein gene encoding MeCP2 are associated with Rett syndrome. In this study, we used transient expression systems to investigate the functional significance of mutations seen in patients with Rett syndrome. Missense mutations in the methyl-CpG-binding domain were analyzed by the transfection in mouse L929 cells and Drosophila SL2 cells. The L929 cells were utilized to investigate the effects of mutations on the affinity for heterochromatin, where methylated CpG dinucleotides are extremely enriched. The SL2 cells were utilized to analyze their effects on transcriptional repression activities. R106W and F155S mutations led to the substantial impairment of MeCP2 functions, showing the loss of accumulation of the mutated protein to mouse heterochromatin and the reduction of the transcriptional repressive activity in Drosophila SL2 cells. Intriguingly, the R133C mutant retained the functionality equivalent to MeCP2 in these analyses. On the other hand, the T158M mutation exhibited the intermediate level of the impairment of functions in both analyses. Thus, these functional assays are useful to evaluate the consequences of mutation in the methyl-CpG-binding domain of MeCP2 and provide an insight into the relationship between the genotype and the severity of Rett syndrome.

Neurophysiology of Rett syndrome

Neurophysiological studies on Rett syndrome (RTT) are reviewed, and pathophysiology of RTT is discussed. The electroencephalography (EEG), sensory evoked potentials (SEP), sleep-wake rhythm study and polysomnography (PSG) study showed age-dependent characteristics. PSG revealed the brainstem and midbrain monoaminergic systems are deranged from early developmental stage, that is serotonin and noradrenaline systems seem to be hypoactive and dopaminergic system is also hypoactive associated with receptor supersensitivity. These monoaminergic systems are known to influence the maturation of the higher neuronal systems at specific areas and at specific ages. Particularly the synaptogenesis of the cerebral cortex is modulated by region or layer specifically from an early stage of the development. The observations made in EEG and SEP studies also suggested specific subcortical and cortical involvements taking place during the development. The age-dependent appearance of characteristic clinical features of RTT, and the variation of the clinical severities, e.g. classical, variant, form fruste, etc., can also be explained by the specific features of these monoaminergic systems. Furthermore, analysis of the components of rapid eye movement sleep suggested the onset of RTT lies between 36 gestational weeks to 3-4 months postnatally. The discovery of the mutations of methyl-CpG-binding protein 2 (MECP2) gene as the causative gene of RTT is an epoch helping not only to understand the pathophysiology of RTT but also various neurodevelopmental disorders.

Development of language in Rett syndrome

Ninety-nine cases of Rett syndrome (RTT) diagnosed clinically (age range 3 years 6 months to 29 years 9 months) were evaluated for the ability of language. The presence of meaningful words, vocabularies, and ages at the start and disappearance of speech were assessed. Phenotype/genotype correlation was evaluated in 22 cases in whom mutations of the genes of methyl-CpG-binding protein 2 (MECP2) existed. Fifty-five cases (55.5%) could speak some words, and of them eight cases (14.5%) spoke two-word sentences. No case had more than 40 words. The vocabularies were mainly bilabial words, known as the characteristics of the initial words in normal children. They began to utter a word between 12 and 48 months, and most of them (85.4%) before 20 months. Those who spoke two-word sentence(s) began to utter a word earlier (10.4+/-3.7 months) than others (17.1+/-9.8 months). Thirty-three cases lost their word(s) in 12-36 months. Among 22 gene-proven cases two cases with mutation of R133C and two cases with R294X had word(s), but another two cases with T158M had not. In RTT a delay in the neuronal systems involved in normal speech development was suggested and its severity seemed to depend on the loci of mutation.

Bile acids regulate RANTES gene expression through its cognate NF-kappaB binding sites

Regulated upon activation, normal T-cells expressed and secreted (RANTES) mainly migrates memory type CD4+ T-lymphocytes to inflamed tissues. In this study, we examined effects of bile acids on RANTES gene expression in human hepatoma cells. Upon stimulation with hydrophobic bile acids, RANTES proteins were clearly increased. Semiquantitative RT-PCR analysis revealed that chenodeoxycholic acid (CDCA) induced RANTES mRNA expression. Moreover, RANTES was transcriptionally induced in two hepatoma cell lines by CDCA, presumably via its cognate NF-kappaB binding sites in the RANTES promoter. Electrophoretic mobility shift assay revealed that hydrophobic bile acids induced DNA-binding activity of NF-kappaB. Additionally, the magnitude of inducibility was closely associated with the hydrophobicity of bile acids. In conclusion, we might indicate that bile acids induced RANTES gene expression in human hepatoma cells, possibly suggesting that bile acids play an important role in migration of inflammatory cells by RANTES to the liver in patients with primary biliary cirrhosis.

A mutant form of JAB/SOCS1 augments the cytokine-induced JAK/STAT pathway by accelerating degradation of wild-type JAB/CIS family proteins through the SOCS-box

Cytokines exert biological functions by activating Janus tyrosine kinases (JAKs), and JAK inhibitors JAB (also referred to as SOCS1 and SSI1) and CIS3 (SOCS3) play an essential role in the negative regulation of cytokine signaling. We have found that transgenic (Tg) mice expressing a mutant JAB (F59D-JAB) exhibited a more potent STAT3 activation and a more severe colitis than did wild-type littermates after treatment with dextran sulfate sodium. We now find that there is a prolonged activation of JAKs and STATs in response to a number of cytokines in T cells from Tg mice with lck promoter-driven F59D-JAB. Overexpression of F59D-JAB also sustained activation of JAK2 in Ba/F3 cells. These data suggested that F59D-JAB up-regulated STAT activity by sustaining JAK activation. To elucidate molecular mechanisms related to F59D-JAB, we analyzed the effects of F59D-JAB on the JAK/STAT pathway using the 293 cell transient expression system. We found that the C-terminal SOCS-box played an essential role in augmenting cytokine signaling by F59D-JAB. The SOCS-box interacted with the Elongin BC complex, and this interaction stabilized JAB. F59D-JAB induced destabilization of wild-type JAB, whereas overexpression of Elongin BC canceled this effect. Levels of endogenous JAB and CIS3 in T cells from F59D-JAB Tg-mouse were lower than in wild-type mice. We propose that F59D-JAB destabilizes wild-type, endogenous JAB and CIS3 by chelating the Elongin BC complex, thereby sustaining JAK activation.

Development of species-specific PCR techniques for the detection of tortoise herpesvirus

Previously, a nested polymerase chain reaction (PCR) was employed with consensus degenerate primers targeting highly conserved motifs within herpesviral DNA polymerase genes to detect a newly described tortoise herpesvirus. However, nucleotide sequence information obtained from the final amplified fragment was restricted to a small region of 181 bp. In the present study, additional sequences flanking this segment were determined from a PCR product successfully amplified using a set of known degenerate primers, which covered a 692-bp region within the tortoise herpesviral DNA polymerase gene. Polymerase chain reaction primers for specific amplification of the tortoise herpesviral DNA were designed on the basis of these nucleotide sequences and successfully amplified tortoise herpesviral DNA from the tissues of tortoises that were well characterized histopathologically with herpesviral infection. The lower limit of detection was 1,000 herpesviral DNA equivalents in the presence of normal tortoise genomic DNA. Furthermore, a more sensitive and specific PCR technique for the identification of herpesviral infections in tortoises was developed employing a heminested form, which will enable the detection of latent infections or herpesvirus carriers in tortoises.

Mammalian homologue of E. coli Ras-like GTPase (ERA) is a possible apoptosis regulator with RNA binding activity

BACKGROUND

ERA (Escherichia coli Ras-like protein) is an E. coli GTP binding protein that is essential for proliferation. A DNA database search suggests that homologous sequences with ERA exist in various organisms including human, mouse, Drosophila, Caenorhabditis elegans and Antirrhinum majus. However, the physiological function of eukaryotic ERA-like proteins is not known.

RESULTS

We have cloned cDNAs encoding the entire coding region of a human homologue (H-ERA) and a mouse homologue (M-ERA) of ERA. The mammalian homologue of ERA consists of a typical GTPase/GTP-binding domain and a putative K homology (KH) domain, which is known as an RNA binding domain. We performed transfection experiments with wild-type H-ERA or various H-ERA mutants. H-ERA possessing the amino acid substitution mutation into the GTPase domain induced apoptosis of HeLa cells, which was blocked by Bcl-2 expression. Deletion of the C-terminus, which contains a part of the KH domain, alleviated apoptosis by the H-ERA mutant, suggesting the importance of this domain in the function of H-ERA. We have also shown the RNA binding activity of H-ERA by pull-down experiments using RNA homopolymer immobilized on beads or recombinant H-ERA proteins.

CONCLUSION

Our data suggest that H-ERA plays an important role in the regulation of apoptotic signalling with its GTPase/GTP binding domain.

[A male case of primary bilateral breast cancers during estrogen therapy for prostate cancer]

An 82-year old man received total androgen blockade therapy (bilateral orchiectomy and 375 mg/day flutamide) for the treatment of stage C prostate cancer. Serum PSA levels were undetectable for 13 months and thereafter increased gradually. We administered estramustine phosphate sodium (EPS) instead of flutamide under the diagnosis of hormone refractory prostate cancer. EPS therapy was discontinued after 9 months because serum PSA levels increased again. Then, the patient complained of bilateral breast nodules and pain. Bilateral mammectomies were performed due to bilateral breast cancers which had been diagnosed by aspiration biopsies and radiographic examinations, but he died four months after the operations. Final pathological diagnosis was ductal adenocarcinoma of the breasts. Immunohistochemical study revealed expressions of PSA in the breast cancers. We diagnosed double cancers of the prostate and the breast because of the different expression patterns of progesterone receptor between them. We review the literatures and discuss the differential diagnosis of prostate cancer and PSA-producing breast cancer.

Parents concordant for major depressive disorder and the effect of psychopathology in offspring

BACKGROUND

Concordance for major depressive disorder (MDD) between parents could happen for different reasons. Regardless of the origin and the frequency of the concordance, the effect on offspring of having two parents affected with MDD may be serious. The sex of the affected parent and offspring may also be a important risk factor for MDD in offspring.

METHODS

We examined the increased risk of psychopathology among offspring of the four parental mating groups: both parents affected with MDD (N = 53); only mother affected (N = 31); only father affected (N = 65); and, neither parents affected (N = 33). Parents and offspring were assessed by direct interview, conducted blind and independently of each other.

RESULTS

Among the four parental mating groups, offspring of both parents affected had the highest risk of MDD, anxiety disorder and alcohol dependence, and the earliest age of onset for MDD. There were two exceptions: the highest risk of conduct disorder and of drug dependence was in the groups where only the father was affected and where only the mother was affected, respectively. Mother's MDD was a stronger predictor of MDD in male compared to female offspring. Father's MDD was a stronger predictor of MDD in female compared to male offspring.

CONCLUSION

Having two parents with MDD increases the risk of psychiatric disorders in offspring. A clear dose-response relationship between the number of affected parents and psychiatric disorders in offspring was observed. The sex of the affected parent and of the offspring is important in determining the risk to offspring. For an examination of the risk to psychopathology in offspring, diagnosis status of both parents should be considered.

Possible involvement of amino acid transporters on S-nitroso-cysteine-induced inhibition of arachidonic acid release in PC12 cells

Previously, we proposed that S-nitroso-cysteine (SNC) was incorporated via the L-type-like amino acid transporters in rat brain slices. In PC12 cells (rat neuronal cell line), SNC inhibited [(3)H]arachidonic acid (AA) release induced by mastoparan (wasp venom peptide). We investigated the involvement of amino acid transporters on SNC-induced inhibition of [(3)H]AA release in PC12 cells. SNC inhibited mastoparan-stimulated [(3)H]AA release in a concentration-dependent manner in normal Na(+)- and low Na(+)-containing buffer. The inhibitory effect of 0.6 mM SNC in low Na(+) buffer decreased by 10 mM L-leucine, L-phenylalanine, L-methionine and L-cysteine. In contrast, L-alanine, L-threonine, L-valine or L-isoleucine showed very limited effects. Addition of L-leucine and L-phenylalanine, but not L-alanine or L-valine, also decreased the inhibitory effect of SNC on ionomycin/Na(3)VO(4)-stimulated [(3)H]AA release in normal Na(+) buffer. These findings suggest that SNC is incorporated via the amino acid transporters and inhibits AA release in PC12 cells.

Elongated dermatan sulphate in post-inflammatory healing skin distributes among collagen fibrils separated by enlarged interfibrillar gaps

It has been reported that the disaccharide composition of dermatan sulphate shows transient changes after epicutaneous application of the hapten 2,4-dinitrofluorobenzene to mouse skin, and that these changes are most conspicuous in healing skin on day 15 after chemical insult [Kuwaba, Nomura, Irie and Koyama (1999) J. Dermatol. Sci. 19, 23-30]. In the present study it was found that the molecular size of dermatan sulphate was increased on day 15 after hapten application. The molecular size of decorin increased in healing skin, whereas the size of dermatan-sulphate-depleted core protein did not increase. The length and localization of decorin dermatan sulphate were investigated by electron microscopy. Dermatan sulphate filaments oriented orthogonally to collagen fibrils were longer in healing skin than in control skin. In control skin, dermatan sulphate filaments were found among tightly packed collagen fibrils. In contrast, the interfibrillar gaps between each collagen fibril were enlarged in healing skin; elongated dermatan sulphate filaments extended from the surface of collagen fibrils across the enlarged gap. These results suggest that the increase in molecular size of decorin dermatan sulphate is important in organizing collagen fibrils separated by enlarged interfibrillar gaps in healing skin.

Dioxin detection based on immunoassay using a polyclonal antibody against octa-chlorinated dibenzo-p-dioxin (OCDD)

An enzyme-linked immunosorbent assay (ELISA) using a polyclonal antibody against octa-chlorinated dibenzo-p-dioxin (OCDD) is presented. This method is based on a competitive reaction between OCDD and OCDD-HRP (horseradish peroxidase) conjugate against the antibody, whereby OCDD-HRP is detected colorimetrically at 450 nm. The detection limit of OCDD was 0.78 pg mL(-1). Optimizing the reaction conditions of the assay, cross reactivities of some dioxins against the antibody are discussed.

International cooperation in neonatal screening: technical training course for newborn and infant screening

We report the outline and results of our experience with a group training course of neonatal screening for health care professionals in developing countries. Sapporo City Institute of Public Health (SCIPH) has been offered a training course on neonatal screening once a year since 1991 under the Technical Training Program of the Japan International Cooperation Agency (JICA). The aims of this training course are to enhance the participants' technical knowledge and skills, and also to deepen their understanding of the principle of neonatal screening as well as the relevant diseases. Lectures and laboratory practice on phenylketonuria (PKU), congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH) and neuroblastoma are included in the 3-month program. After the completion of the training, participants are expected to play a major role in establishing and expanding neonatal screening system in each of their countries. We have received a total of 67 participants from 25 countries until March 1998: 58 pediatricians; 2 gynecologists; 6 biochemists; 1 administrative officer. After they returned to their countries, 11 engaged in neonatal screening and started PKU and CH screening in their institute, city or province in Argentina, Brazil, Mexico, Peru and Thailand. We believe that these results fulfilled our objectives. Also, for follow-up, SCIPH has been giving information and consultation to the participants on requests. This international cooperation network could also benefit our present network of the International Society Screening in the future.