Colocalization of a carnosine-splitting enzyme,tissue carnosinase (CN2)/cytosolic non-specific dipeptidase 2 (CNDP2), with histidine decarboxylase in the tuberomammillary nucleus of the hypothalamus

Carnosine is a naturally occurring dipeptide (β-alanyl-l-histidine) present in mammalian tissues such as the brain and skeletal muscles. Carnosine is not only a radical scavenger but also a possible neurotransmitter-like molecule that regulates neuronal functions such as hypothalamic control of the autonomic nervous system. CN2 (CNDP2) is a cytosolic enzyme that can hydrolyze carnosine to yield l-histidine and β-alanine. In order to understand the functions of carnosine and CN2 in the brain, we have investigated the immunohistochemical localization of CN2 in the hypothalamus. CN2-immunoreactivity was highly concentrated in neuronal cells in the dorsal part of the tuberomammillary nucleus of the posterior hypothalamus. Since the tuberomammillary nucleus is the exclusive origin of histaminergic neurons, we further investigated whether CN2 is present in the histaminergic neurons. We found that CN2-immunoreactivity was colocalized with that of histidine decarboxylase, which is the key enzyme for histamine biosynthesis specifically expressed in the histaminergic neurons of the tuberomammillary nucleus. These results suggest that CN2 is highly expressed in the histaminergic neurons in the tuberomammillary nucleus, implying that it may supply histidine to histaminergic neurons for histamine synthesis.     

Estrogen determines sex differences in airway responsiveness after allergen exposure

The female hormone estrogen is an important factor in the regulation of airway function and inflammation, and sex differences in the prevalence of asthma are well described. Using an animal model, we determined how sex differences may underlie the development of altered airway function in response to allergen exposure. We compared sex differences in the development of airway hyperresponsiveness (AHR) after allergen exposure exclusively via the airways. Ovalbumin (OVA) was administered by nebulization on 10 consecutive days in BALB/c mice. After methacholine challenge, significant AHR developed in male mice but not in female mice. Ovariectomized female mice showed significant AHR after 10-day OVA inhalation. ICI182,780, an estrogen antagonist, similarly enhanced airway responsiveness even when administered 1 hour before assay. In contrast, 17beta-estradiol dose-dependently suppressed AHR in male mice. In all cases, airway responsiveness was inhibited by the administration of a neurokinin 1 receptor antagonist. These results demonstrate that sex differences in 10-day OVA-induced AHR are due to endogenous estrogen, which negatively regulates airway responsiveness in female mice. Cumulatively, the results suggest that endogenous estrogen may regulate the neurokinin 1-dependent prejunctional activation of airway smooth muscle in allergen-exposed mice.     

Thromboxane A2 modulates interaction of dendritic cells and T cells and regulates acquired immunity

Physical interaction of T cells and dendritic cells (DCs) is essential for T cell proliferation and differentiation, but it has been unclear how this interaction is regulated physiologically. Here we show that DCs produce thromboxane A2 (TXA2), whereas naive T cells express the thromboxane receptor (TP). In vitro, a TP agonist enhances random cell movement (chemokinesis) of naive but not memory T cells, impairs DC-T cell adhesion, and inhibits DC-dependent proliferation of T cells. In vivo, immune responses to foreign antigens are enhanced in TP-deficient mice, which also develop marked lymphadenopathy with age. Similar immune responses were seen in wild-type mice treated with a TP antagonist during the sensitization period. Thus, TXA2-TP signaling modulates acquired immunity by negatively regulating DC-T cell interactions.     

Pregnancy Outcomes in 2 Women Born with Complex Anorectal Malformations: Challenges and Considerations

BackgroundComplex anorectal malformations (ARMs) are a group of rare congenital malformations involving numerous anomalies that require reconstruction and can affect sexuality, fertility, and pregnancy outcomes. Few cases of pregnancy in complex ARM patients have been reported.CasesWe report on 2 patients with ARMs who delivered 3 term infants, all by cesarean section with successful collaboration between pediatric urologists and obstetricians. Both patients fully recovered with no long-term consequences after experiencing maternal morbidities including urinary infections, clitoral abscesses, vaginal lacerations, extensive adhesive disease, bladder injury, and maternal hemorrhage.Summary and ConclusionIn managing pregnancies and deliveries in women with complex ARMs, coordination between obstetricians, pediatric urologists, and pediatric surgeons is crucial.     

Effect of the C3a-Receptor Antagonist SB 290157 on Anti-OVA Polyclonal Antibody–Induced Arthritis

It was investigated whether the C3a-receptor antagonist (C3aRA) SB 290157 was involved in the suppression of anti-OVA pAb–induced arthritis because it is well known that anaphylatoxin C3a plays a crucial role in the development of an effective inflammatory response during complement activation. Anti-OVA pAb–induced arthritis was induced in DBA/1J mice by administration of anti-OVA pAb 0.5 h prior to intra-articular (i.a.) injection of OVA (0 h). Two peaks of joint swelling were observed at 0.5 and 3 h. The role of C3aRA in arthritis was investigated by injection of SB 290157 at concentrations of 10 and 30 mg/kg at 0 and 2 h. The antagonist was able to reduce joint swelling only at 3 h, and about 50% inhibition of joint swelling was observed with the concentration of 30 mg/kg. The C3 level was significantly decreased at 3 h compared with naïve mice showing complement consumption. Furthermore, the C3 activation was observed and increased corresponding to the graded concentration of anti-OVA pAb. The results also revealed that the C3aRA was able to reduce the expression of IL-1β in synovial tissue. Taken together, the results suggested that C3aRA may be effective in the inhibition of arthritis.     

Combinations of cytogenetics and international scoring system can predict poor prognosis in multiple myeloma after high‐dose chemotherapy and autologous stem cell transplantation

High‐dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a standard therapy for newly diagnosed multiple myeloma. Combinations of recently proposed prognostic factors such as cytogenetics and international scoring system (ISS) may be useful to predict prognosis after ASCT. This study evaluated 60 consecutive patients who underwent ASCT in four institutes. The median age of patients was 57 years old. Cytogenetic analyses of bone marrow at diagnosis detected metaphase abnormalities in 9 of 51 patients and interphase abnormalities in six of 35 patients (17p13 deletion, t(4;14) and t(14;16)). Seventeen patients had ISS stage 3 at diagnosis. Twenty‐five patients who had any of these risk factors were defined as high risk. All patients were conditioned with high‐dose melphalan. With a median follow‐up of 3.4 years, overall survival and event‐free survival at 3 years were significantly worse in high‐risk patients (48% vs. 97%; P = 0.0005 and 16% vs. 37%; P = 0.038, respectively) despite the higher CR plus VGPR rate among high‐risk patients. In addition, survival at 1 year after progression was significantly worse in high‐risk patients despite salvage chemotherapy containing thalidomide (32% vs. 100%, P = 0.0001). Combinations of cytogenetics and ISS could readily predict prognosis. Quality of response is a poor surrogate marker for ultimate outcome. High‐risk patients may need more effective treatment. Am. J. Hematol. 2009. © 2009 Wiley‐Liss, Inc.     

Genetic polymorphism of aldehyde oxidase in Donryu rats.

One of major metabolic pathways of [(+/-)-4-(4-cyanoanilino)-5,6-dihydro-7-hydroxy-7H-cyclopenta[d]-pyrimidine] (RS-8359), a selective and reversible monoamine oxidase type A inhibitor, is the aldehyde oxidase-catalyzed 2-hydroxylation at the pyrimidine ring. Donryu rats showed a dimorphic pattern for the 2-oxidation activity with about 20- to 40-fold variations in the Vmax/Km values between a low and a high activity group. The rats were classified as extensive metabolizers (EM) and poor metabolizers (PM) of RS-8359, of which ratios were approximately 1:1. One rat among the EM rats of each sex showed extremely high activity, and they were referred to as ultrarapid metabolizers. There was no significant difference in the expression levels of mRNA of aldehyde oxidase between the EM and PM rats. Analysis of nucleotide sequences showed four substitutions, of which the substitutions at 377G>A and 2604C>T caused 110Gly-Ser and 852Ala-Val amino acid changes, respectively. Amino acid residue 110 is located very near the second Fe-S center of aldehyde oxidase. Its change from nonchiral Gly to chiral Ser may result in a conformational change of aldehyde oxidase protein with the shift of isoelectric point value from 5.0 in the EM rats to 6.2 in the PM rats. The 110Gly-Ser amino acid substitution (377G>A) may be primarily responsible for the variations of aldehyde oxidase activity observed in Donryu rats, in addition to the difference of expression levels of aldehyde oxidase protein. If a new drug candidate is primarily metabolized by aldehyde oxidase, attention should be given to using a rat strain with high aldehyde oxidase activity and small individual variation.     

Late relapse of small cell lung cancer treated with radiation therapy alone — case report

This report describes an unusual case of a long-term survivor with small cell lung cancer (SCLC), treated with radiation therapy alone having a late relapse with solitary brain metastasis 6.5 years after the initial treatment. He received radiation therapy and died of the brain metastasis 8.5 years after the initial treatment. Autopsy revealed no tumor recurrence at the primary site and no distant metastases except for the brain. The histology of the brain tumor was small cell carcinoma.     

Lack of influence of low blood cholesterol levels on pancreatic carcinogenesis after initiation with N-nitrosobis(2-oxopropyl)amine in Syrian golden hamsters

The effects of a cholesterol-free diet, a cholesterol-free dietsupplemented with sesamin, and a diet supplemented with sesaminon pancreatic carcinogenesis of N-nitrosobis(2-oxopropyl) amine(BOP) were investigated in 140 female Syrian golden hamsters.BOP (70 and 20 mg/kg body wt) was injected s.c. twice at aninterval of 2 weeks at the beginning of the experiment. Starting3 weeks thereafter, the animals were maintained on basal diet,cholesterol-free diet, basal diet plus sesamin, or cholesterol-freediet plus sesamin for a further 15 weeks. All surviving hamsterswere killed at week 18, and the pancreatic tissues examinedhistologically. The incidences of pancreatic neoplastic andpreneoplastic lesions in each group did not show any statisticallysignificant variation. The cholesterol-free diet significantlydecreased the cholesterol contents of the serum, pancreas andliver, and sesamin supplement significantly decreased the cholesterolcontents of the serum and liver. Both the cholesterol-free dietand sesamin decreased the serum lipoperoxide levels. The resultsthus indicated that low cholesterol per se and sesamin exertno significant influence on BOP-initiated pancreatic carcinogenesisin hamsters, at least within the 4 month period after carcinogentreatment.     

Different Roles of 8-Hydroxyguanine Formation and 2-Thiobarbituric Acid-reacting Substance Generation in the Early Phase of Liver Carcinogenesis Induced by a Choline-deficient, l-Amino Acid-defined Diet in Rats

The present study was performed to assess the roles of hepatocellular oxidative damage to DNA and constituents other than DNA in rat liver carcinogenesis caused by a choline-deficient, l -amino acid-defined (CDAA) diet by examining the effects of the antioxidant N, N' -diphenyl- p -phenylenediamine (DPPD). The parameters used for cellular oxidative damage were the level of 8-hydroxyguanine (8-OHGua) for DNA and that of 2-thiobarbituric acid-reacting substance (TBARS) for constituents other than DNA. A total of 40 male Fischer 344 rats, 6 weeks old, were fed the CDAA diet for 12 weeks with or without DPPD (0.05, 0.10 or 0.20%) or butylated hydroxytoluene (BHT, 0.25%). In the livers of the rats, the numbers and sizes of glutathione S -transferasc (EC 2.5.1.18) placental form (GSTP)- and/or γ-glutamyltransferase (GGT, EC 2.3.2.2)-positive lesions and levels of 8-OHGua and TBARS were determined. The GSTP-positive lesions of 0.08 mm² or larger were all stained positively for GGT as well in cross-sectional area, whereas the smaller lesions were generally negative for GGT. DPPD and BHT reduced the size of the GSTP-positive lesions without affecting their total numbers. At the same time, they reduced TBARS generation without affecting 8-OHGua formation in DNA. The present results indicate that oxidative DNA damage (represented by 8-OHGua formation) and damage to constituents other than DNA (represented by TBARS generation) may play different roles in rat liver carcinogenesis caused by the CDAA diet; the former appears to be involved in the induction of phenotypically altered hepatocyte populations while the latter may be related to the growth of such populations.