Diffuse pulmonary arteriovenous fistulae secondary to patent ductus venosus

European Journal of Pediatrics -     

Rabbit model for human EBV-associated hemophagocytic syndrome (HPS): sequential autopsy analysis and characterization of IL-2-dependent cell lines established from herpesvirus papio-induced fatal rabbit lymphoproliferative diseases with HPS

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis or T-cell lymphoproliferative diseases (LPD). To elucidate the true nature of fatal LPD observed in Herpesvirus papio (HVP)-induced rabbit hemophagocytosis, reactive or neoplastic, we analyzed sequential development of HVP-induced rabbit LPD and their cell lines. All of the seven Japanese White rabbits inoculated intravenously with HVP died of fatal LPD 18 to 27 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in five of these seven rabbits. Sequential autopsy revealed splenomegaly and swollen lymph nodes, often accompanied by bleeding, which developed in the last week. Atypical lymphoid cells infiltrated many organs with a "starry sky" pattern, frequently involving the spleen, lymph nodes, and liver. HVP-small RNA-1 expression in these lymphoid cells was clearly demonstrated by a newly developed in situ hybridization (ISH) system. HVP-ISH of immunomagnetically purified lymphoid cells from spleen or lymph nodes revealed HVP-EBER1+ cells in each CD4+, CD8+, or CD79a+ fraction. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by PCR or Southern blot analysis. Clonality analysis of HVP-induced LPD by Southern blotting with TCR gene probe revealed polyclonal bands, suggesting polyclonal proliferation. Six IL-2-dependent rabbit T-cell lines were established from transplanted scid mouse tumors from LPD. These showed latency type I/II HVP infection and had normal karyotypes except for one line, and three of them showed tumorigenicity in nude mice. These data suggest that HVP-induced fatal LPD in rabbits is reactive polyclonally in nature.     

Isolation and characterization of the stage-specific cytochrome b small subunit (CybS) of Ascaris suum complex II from the aerobic respiratory chain of larval mitochondria

We recently reported that Ascaris suum mitochondria express stage-specific isoforms of complex II: the flavoprotein subunit and the small subunit of cytochrome b (CybS) of the larval complex II differ from those of adult enzyme, while two complex IIs share a common iron-sulfur cluster subunit (Ip). In the present study, A. suum larval complex II was highly purified to characterize the larval cytochrome b subunits in more detail. Peptide mass fingerprinting and N-terminal amino acid sequencing showed that the larval and adult cytochrome b (CybL) proteins are identical. In contrast, cDNA sequences revealed that the small subunit of larval cytochrome b (CybS(L)) is distinct from the adult CybS (CybS(A)). Furthermore, Northern analysis and immunoblotting showed stage-specific expression of CybS(L) and CybS(A) in larval and adult mitochondria, respectively. Enzymatic assays revealed that the ratio of rhodoquinol-fumarate reductase (RQFR) to succinate-ubiquinone reductase (SQR) activities and the K(m) values for quinones are almost identical for the adult and larval complex IIs, but that the fumarate reductase (FRD) activity is higher for the adult form than for the larval form. These results indicate that the adult and larval A. suum complex IIs have different properties than the complex II of the mammalian host and that the larval complex II is able to function as a RQFR. Such RQFR activity of the larval complex II would be essential for rapid adaptation to the dramatic change of oxygen availability during infection of the host.     

Comparison of body size and composition between young adult Japanese-Americans and Japanese nationals in the 1980s

BACKGROUND: Data on body composition of American-born Japanese (Japanese-Americans) are scarce. Studies on differences of body composition between Japanese-Americans and Japanese nationals at various stages of life as well as at various times of measurements are useful for understanding the impact of lifestyle changes on body composition in the two societies. AIM: To see the differences in body size and composition between young adult Japanese-Americans and Japanese nationals. SUBJECTS AND METHODS: Body size and composition of 50 Japanese-Americans consisting of 28 males and 22 females ranging in age from 18 to 23 years were compared with Japanese nationals matched for age and height. Body composition was measured using the underwater weighing method. The study was conducted in the 1980s in the USA and Japan. RESULTS: The average percentage body fat of males was 13.7% for both Japanese-Americans and Japanese nationals, and that of females was approximately 24% for both groups, even though Japanese-American males and females had significantly greater body weight, fat-free mass, and body mass index than Japanese nationals. CONCLUSION: Although young adult Japanese-Americans showed larger body size than Japanese nationals, their percentage fat did not differ at this stage of life in the 1980s.     

Effects of long-term hypoxia and development on cardiac contractile proteins in fetal and adult sheep

OBJECTIVE: We studied the effect of long-term, high-altitude hypoxia on cardiac myosin, actin, and troponin T (TnT) isoforms and Ca(2+)- and Mg(2+)-activated myofibrillar adenosine triphosphatase (ATPase) activities in fetal and adult sheep. METHODS: We exposed pregnant (beginning at day 30 of gestation) and nonpregnant sheep to high altitude (3820 m) for 110 days. Myosin, actin, and TnT isoforms were analyzed by Western analysis. In purified myofibrillar preparations, Ca(2+)(-) and Mg(2+)-ATPase activities were measured by the appearance of inorganic phosphate after the addition of NaATP and various concentrations of either calcium or magnesium to the reaction mixture. RESULTS: We found no change in myosin, actin, or TnT isoform composition after exposure to long-term hypoxia in either fetal or adult sheep. However, Mg(2+)-activated myofibrillar ATPase activity decreased significantly in the right ventricle of both fetus and adult after hypoxic exposure. There was also a significant maturational increase in both Ca(2+)- and Mg(2+)-ATPase activity in control animals. CONCLUSION: The decrease in Mg(2+)-activated myofibrillar ATPase activity might affect the decrease in cardiac contractility previously noted in the right ventricle of fetal sheep after exposure to long-term hypoxia. Likewise, the increase in Ca(2+)- and Mg(2+)-activated ATPase activities from the fetus to adult could partially explain the previously found maturational increase in cardiac contractility.     

Interleukin-13 induces goblet cell differentiation in primary cell culture from Guinea pig tracheal epithelium

The Th2 cytokines, interleukin (IL)-4 and IL-13, bind to IL-4Ralpha, and cause goblet cell metaplasia/hyperplasia with increased mucin expression in vivo. However, there is not enough evidence that these cytokines directly induce mucin production in vitro. In this study, primary epithelial cells from guinea pig trachea were cultured at an air-liquid interface, and immediately after achieving confluence at Day 7 they were treated with human recombinant IL-4 or IL-13 for 14 d. IL-13-treated cells consisted of a large number of fully mature goblet cells with a smaller number of ciliated cells. Secretory granules of the goblet cells were positive for both periodic acid-Schiff and toluidine blue, and showed exocytosis. By contrast, IL-4 failed to induce goblet cell differentiation. The electric resistances of IL-13-treated cells were lower than those of IL-4-treated cells and nontreated cells, suggesting leaky epithelia. MUC5AC protein level in cell lysates measured by ELISA was several-fold higher in IL-13-treated cells than in nontreated cells, whereas the level in IL-4-treated cells was not changed. These data suggest that human recombinant IL-13, but not IL-4, can induce differentiation into mature goblet cells that produce MUC5AC protein in guinea pig tracheal epithelial cells in vitro.     

Reperfusion response changes induced by repeated,sustained contractions in normal human masseter muscle

The purpose was to evaluate the intramuscular reperfusion response characteristics associated with repeated isometric contractions in normal human masseter. Intramuscular blood volume was quantified with a near-infrared spectroscopic device that measured the total haemoglobin (Hb) concentration in the muscle. Electromyographic (EMG) activity from the masseter and total bite forces were also recorded. Sixteen healthy volunteers, eight females and eight males, without masticatory muscle pain participated. They were asked first to clench their teeth for as long as possible at 50% of their maximum voluntary contraction (MVC). This was followed by a 60s rest and then immediately by a standard clenching task (50% MVC for 30s) and a 60s recovery period, immediately after which they were asked to repeat exactly the same procedure, with a final 5 min recovery period after the second 30s contraction. Bite force, EMG and Hb concentration were measured continuously and the duration of the two endurance tasks and the amplitudes of all recorded signals were compared (first trial versus second trial). Specifically, the difference between the lowest Hb (trough) seen during the standardised 30s contractions and the highest (peak) seen just after them was assessed. The trough-to-peak difference in Hb concentration of the second standard contraction task was significantly smaller than that of the first standard task (P<0.05, paired t-test). These data show that with sustained effort the post-contraction vasodilatory reperfusion responses of the human masseter are diminished, suggesting a progressive desensitisation of the vasodilatory system.     

Pharmacokinetic analysis of in vivo disposition of succinylated proteins targeted to liver nonparenchymal cells via scavenger receptors: importance of molecular size and negative charge density for in vivo recognition by receptors

In vivo disposition characteristics of succinylated (Suc-) proteins were studied after intravenous injection in mice in relation to their molecular characteristics as negatively charged macromolecules. Recombinant superoxide dismutase (SOD; molecular mass, 32 kDa), bovine serum albumin (BSA; molecular mass, 67 kDa), and bovine IgG (molecular mass, 150 kDa) were used to produce succinylated derivatives with different degrees of modification. (111)In-labeled Suc-SODs were rapidly excreted into the urine with no significant hepatic uptake. In contrast, (111)In-Suc-BSA and Suc-IgG were significantly taken up by liver nonparenchymal cells via scavenger receptors (SRs) according to the degree of succinylation and the dose injected. Interestingly, highly succinylated BSAs exhibited significant accumulation in the kidney at higher doses when the hepatic uptake was saturated. Pharmacokinetic analysis demonstrated that the hepatic uptake of succinylated proteins depended on the molecular size and the estimated surface density of succinylated amino residues. Further analysis based on a physiological pharmacokinetic model, involving a saturable process with Michaelis-Menten kinetics, revealed that the surface density of negative charges was correlated with the affinity of larger succinylated proteins for the hepatic SRs. Thus, the present study has provided useful basic information for a therapeutic strategy and the molecular design of succinylated proteins for use as drug carriers and therapeutic agents per se for SR-mediated targeting in vivo.