MEK/ERK MAP kinase limits poly I:C-induced antiviral gene expression in RAW264.7 macrophages by reducing interferon-beta expression

Toll-like receptor 3 (TLR3) recognizes viral double-stranded RNA (or the synthetic dsRNA analog poly I:C) and induces a signal transduction pathway that results in activation of transcription factors that induce expression of antiviral genes including type I interferon (IFN-I). Secreted IFN-I positively feeds back to amplify antiviral gene expression. In this report, we study the role of MEK/ERK MAP kinase in modulating antiviral gene expression downstream of TLR3. We find MEK/ERK is a negative regulator of antiviral gene expression by limiting expression of IFN-β. However, MEK/ERK does not limit antiviral responses downstream of the type I interferon receptor. These findings provide insights into regulatory mechanisms of antiviral gene expression and reveal potential targets for modulating antiviral immunity.

B-Cell Control of Regulatory T Cells in Friend Virus Infection

B lymphocytes have well-established effector roles during viral infections, including production of antibodies and functioning as antigen-presenting cells for CD4+ and CD8+ T cells. B cells have also been shown to regulate immune responses and induce regulatory T cells (Tregs). In the Friend virus (FV) model, Tregs are known to inhibit effector CD8+ T-cell responses and contribute to virus persistence. Recent work has uncovered a role for B cells in the induction and activation of Tregs during FV infection. In addition to inducing Tregs, B cell antibody production and antigen-presenting cell activity is a target of Treg suppression. This review focuses on the dynamic interactions between B cells and Tregs during FV infection.

Quercetin Inhibits Proliferation and Induces Apoptosis of B16 Melanoma Cells In Vitro

Malignant melanoma is an aggressive cancer with a poor prognosis despite numerous advances in therapeutic strategies. Quercetin is a plant-derived flavonoid suggested to have potent anticancer properties. Quercetin has no demonstrable toxicity in humans, further supporting the possibility of using quercetin therapeutically. We chose to investigate quercetin efficacy against B16 murine melanoma cells and identify the mechanisms of anticancer activity. Treatment of B16 melanoma cells with 50 μg/mL quercetin resulted in a 75% reduction in viability from 6 through 48 h post-treatment. The reduction in cancer cell viability was comparable to or greater than what was observed with etoposide, an established chemotherapeutic. Specifically, we found Quercetin reduced the proliferation of B16 melanoma cells at 48 h as much or more than etoposide. Although quercetin reduced the proportion of cells in the S and G2/M stages of the cell cycle, this could largely be explained by an increase in the subG1 population in quercetin-treated cells (suggesting apoptosis). Quercetin-induced apoptosis was confirmed by flow cytometry analysis of Annexin V+ cells. Collectively, our findings demonstrate quercetin reduces proliferation and induces apoptosis of B16 melanoma cells in vitro.

Regulatory T cells suppress virus-specific antibody responses to Friend retrovirus infection

Recent vaccine studies with experimental antigens have shown that regulatory T cells (Tregs) constrain the magnitude of B cell responses. This homeostatic Treg-mediated suppression is thought to reduce the potential of germinal center (GC) responses to generate autoreactive antibodies. However, essentially opposite results were observed in live influenza infections where Tregs promoted B cell and antibody responses. Thus, it remains unclear whether Tregs dampen or enhance B cell responses, especially during live viral infections. Here, we use mice infected with Friend retrovirus (FV), which induces a robust expansion of Tregs. Depletion of Tregs led to elevated activation, proliferation, and class switching of B cells. In addition, Treg depletion enhanced the production of virus-specific and virus-neutralizing antibodies and reduced FV viremia. Thus, in contrast to influenza infection, Tregs either directly or indirectly suppress B cells during mouse retroviral infection indicating that the ultimate effect of Tregs on B cell responses is specific to the particular infectious agent.

No SEVI-mediated enhancement of rectal HIV-1 transmission of HIV-1 in two humanized mouse cohorts

Amyloid fibrils from semen-derived peptide (SEVI) enhance HIV-1 infectivity in vitro but the ability of SEVI to mediate enhancement of HIV infection in vivo has not been tested. In this study we used immunodeficient mice reconstituted with human immune systems to test for in vivo enhancement of HIV-1 transmission. This mouse model supports mucosal transmission of HIV-1 via the intrarectal route leading to productive infection. In separate experiments with humanized mouse cohorts reconstituted with two different donor immune systems, high dose HIV-1JR-CSF that had been incubated with SEVI amyloid fibrils at physiologically relevant concentrations did not show an increased incidence of infection compared to controls. In addition, SEVI failed to enhance rectal transmission with a reduced concentration of HIV-1. Although we confirmed potent SEVI-mediated enhancement of HIV infectivity in vitro, this model showed no evidence that it plays a role in the much more complex situation of in vivo transmission.

IRF3 deficiency impacts granzyme B expression and maintenance of memory T cell function in response to viral infection

The role of interferon regulatory factor 3 (IRF3) in the innate immune response to infection has been well studied. However, less is known about IRF3 signaling in shaping the adaptive T cell response. To determine the role of IRF3 in the generation and maintenance of effective anti-viral T cell responses, mice deficient in IRF3 were infected with a potentially persistent virus, Theiler's murine encephalomyelitis virus (TMEV) or with a model acute infection, influenza A virus (IAV). IRF3 was required to prevent TMEV persistence and induce robust TMEV specific effector T cell responses at the site of infection. This defect was more pronounced in the memory phase with an apparent lack of TMEV-specific memory T cells expressing granzyme B (GrB) in IRF3 deficient mice. In contrast, IRF3 had no effect on antigen specific T cell responses at the effector stage during IAV infection. However, memory T cell responses to IAV were also impaired in IRF3 deficient mice. Furthermore, addition of cytokines during peptide restimulation could not restore GrB expression in IRF3 deficient memory T cells. Taken together, IRF3 plays an important role in the maintenance of effective anti-viral T cell memory responses.

Interferon response factor 3 is crucial to poly-I:C induced NK cell activity and control of B16 melanoma growth

Interferon Response Factor 3 (IRF3) induces several NK-cell activating factors, is activated by poly-I:C, an experimental cancer therapeutic, but is suppressed during many viral infections. IRF3 Knockout (KO) mice exhibited enhanced B16 melanoma growth, impaired intratumoral NK cell infiltration, but not an impaired poly-I:C therapeutic effect due to direct suppression of B16 growth. IRF3 was responsible for poly-I:C decrease in TIM-3 expression by intratumoral dendritic cells, induction of NK-cell Granzyme B and IFN-γ, and induction of macrophage IL-12, IL-15, IL-6, and IRF3-dependent NK-activating molecule (INAM). Thus, IRF3 is a key factor controlling melanoma growth through NK-cell activities, especially during poly-I:C therapy.

IRF3 helps control acute TMEV infection through IL-6 expression but contributes to acute hippocampus damage following TMEV infection

IRF3 is an innate anti-viral factor whose role in limiting Theiler's murine encephalomyelitis virus (TMEV) infection and preventing TMEV-induced disease is unclear. Acute disease and innate immune responses of macrophages were examined in IRF3 knockout mice compared with C57Bl/6 mice following in vitro or intracranial infection with either TMEV GDVII or DA. IRF3 deficiency augmented viral infection, as well as morbidity and mortality following intracranial infection with neurovirulent TMEV GDVII. In contrast, IRF3 deficiency prevented hippocampal injury following intracranial infection with persistent TMEV DA. The extent of TMEV infection in macrophages from C57Bl/6 mice was significantly less than that in IRF3 deficient macrophages, which was associated with poor IFN-β and IL-6 expression in response to TMEV. Reestablishing IRF3 expression in IRF3 deficient macrophages increased control of TMEV replication and increased expression of IFN-β and IL-6. In addition, IRF3 deficient macrophages failed to exhibit IL-6 antiviral effects, which was associated with inability to sustain IL-6-induced STAT1 activation compared with C57BL/6 macrophages. Altogether, IRF3 contributes to early control of TMEV replication through induction of IL-6 and IFN-β and support of IL-6 antiviral effects, but contributes to TMEV-induced hippocampal injury.

IRF3 and ERK MAP-kinases control nitric oxide production from macrophages in response to poly-I:C

Understanding nitric oxide (NO) in innate anti-viral immunity and immune-mediated pathology is hampered by incomplete details of its transcriptional and signaling factors. We found in macrophages that IRF3, ERK MAP-kinases, and PKR are essential to NO production in response to RNA-virus mimic, poly I:C, a TLR3 agonist. ERK's role in NO induction may be through phosphorylation of serine-171 of IRF3 and expression of NO-inducing cytokines, IL-6 and IFN-β. However, these cytokines induced less NO in IRF3 knockout or knockdown macrophages. These findings show that ERK and IRF3 coordinate induction of NO by macrophages in response to stimulation of TLR3.

IRF3 polymorphisms induce different innate anti-Theiler's virus immune responses in RAW264.7 macrophages

Persistent viral infections can lead to disease such as myocarditis. Theiler's murine encephalomyelitis virus (TMEV) infects macrophages of SJL/J (H-2s) mice establishing persistent infections leading to demyelinating disease. In contrast macrophages from B10.S (H-2s) mice clear TMEV. Activation of the transcription factor IRF3 induces IFNβ, ISG56, and apoptosis for viral clearance, but also inflammatory cytokines, such as IL-23 and IL6, which contribute to disease. Here we identify polymorphisms in the IRF3 of SJL/J versus B10.S mice that are located in DNA binding, nuclear localization, and autoinhibitory domains. SJL-IRF3 expression in RAW264.7 macrophage cells with or without TMEV infection decreased IL-23p19 promoter activity compared with B10S-IRF3. In contrast SJL-IRF3 increased IL-6, ISG56 and IFNβ in response to TMEV. B10S-IRF3 expression augmented apoptotic caspase activation and decreased viral RNA in TMEV-infected macrophages while SJL-IRF3 increased viral replication with less caspase activation. Therefore IRF3 polymorphisms contribute to viral persistence and altered cytokine expression.

Iron-plasma transmission measurements at temperatures above 150 eV

Measurements of iron-plasma transmission at 156+/-6 eV electron temperature and 6.9+/-1.7 x 10(21) cm(-3) electron density are reported over the 800-1800 eV photon energy range. The temperature is more than twice that in prior experiments, permitting the first direct experimental tests of absorption features critical for understanding solar interior radiation transport. Detailed line-by-line opacity models are in excellent agreement with the data.

Hot dense capsule-implosion cores produced by Z-pinch dynamic Hohlraum radiation

Hot dense capsule implosions driven by Z-pinch x rays have been measured using a approximately 220 eV dynamic Hohlraum to implode 1.7-2.1 mm diameter gas-filled CH capsules. The capsules absorbed up to approximately 20 kJ of x rays. Argon tracer atom spectra were used to measure the T(e) approximately 1 keV electron temperature and the n(e) approximately 1-4 x 10(23) cm(-3) electron density. Spectra from multiple directions provide core symmetry estimates. Computer simulations agree well with the peak emission values of T(e), n(e), and symmetry, indicating reasonable understanding of the Hohlraum and implosion physics.

X-ray imaging measurements of capsule implosions driven by a Z-pinch dynamic hohlraum

The radiation and shock generated by impact of an annular tungsten Z-pinch plasma on a 10-mm diam 5-mg/cc CH(2) foam are diagnosed with x-ray imaging and power measurements. The radiative shock was virtually unaffected by Z-pinch plasma instabilities. The 5-ns-duration approximately 135-eV radiation field imploded a 2.1-mm-diam CH capsule. The measured radiation temperature, shock radius, and capsule radius agreed well with computer simulations, indicating understanding of the main features of a Z-pinch dynamic-hohlraum-driven capsule implosion.

Successful use of the "patch, drain, and wait" laparotomy approach to perforated necrotizing enterocolitis: is hypoxia-triggered "good angiogenesis" involved?

The traditional and most frequently employed surgical approach to perforated necrotizing enterocolitis (NEC), laparotomy and bowel resection with enterostomy creation, has been associated with an unacceptably high mortality and major morbidity (sepsis, short-gut syndrome, strictures, long-term total parenteral nutrition (TPN), prolonged and costly hospitalizations with multiple operations, the inevitable open-and-close procedure for "hopeless" extensive gut ischemia in approximately 10% of laparotomy cases, etc.). The use of the laparotomy "patch, drain, and wait" (PD&W) approach to this serious of NEC complication has provided a simple, direct, and effective means of dealing with this problem. The basic principle is to resect no gut and do no enterostomies. The details are presented here as well as the multiple types of "patching" and the importance of use of extensive direct-vision draining with bilateral small Penrose drains from the undersurfaces of both diaphragms into the pelvis with exit sites in both lower quadrants. Proper and effective patching and draining cannot be done blindly,but requires direct vision (laparotomy or laparoscopy). The critical components and timing of the "waiting" are emphasized, including the vital importance of strict avoidance of early post-drainage laparotomy in the 7- to 14-day post-drainage period (whether the drainage is percutaneous, laparotomy PD&W, or laparoscopy PD&W) due to the early, life-threatening-ending hypervascularity that occurs at this time and if left unmolested will function beneficially as life- and gut-saving "good angiogenesis". The bilateral Penrose drains capture fecal fistulas and function quite well as de-facto enterostomies as the peritoneal cavity is rapidly obliterated by adhesions and massive, florid hypervascularity/gut hypoxia triggered "good angiogenesis" (no peritoneal cavity, no peritonitis). Broad-spectrum triple antibiotics and the routine use of TPN contribute to favorable results. The lessons/experiments of nature encountered in newborns with midgut atresia(s) and remarkable levels of gut survival, in the occasional case with only meconium peritonitis and no obstruction ("auto-anastomosis") are pertinent here as the TPN of PD&W is provided in atresia(s) by the maternal-placental circulation and the sterile peritoneal cavity of atresia(s) is simulated by the combination of antibiotics and peritoneal-cavity obliteration. Life- and gut-saving "good angiogenesis" is common to both situations. A 15-year personal experience with the PD&W laparotomy approach to perforated NEC in 23 cases is reported here with no mortality in the initial 60 postoperative days, no major morbidity, and no second operation required in 70% (spontaneous "auto-anastomosis") of cases. All infants with extensive gut ischemia/necrosis (NEC totalis) who would otherwise be classified as "hopeless" and managed by open-and-close only were managed in this experience successfully by PD&W with preservation of both life and an adequate amount of gut, although a second operation was required in these cases to re-establish intestinal continuity. A particularly striking observation was the rapid transition of these infants from profound illness to near-normalcy in a matter of hours after the initiation of PD&W--much like the rapid clinical changes accompanying the lancing of a boil or an abscess. An involvement of hypoxia-induced "good angiogenesis" with marked hypervascularity and involving molecules, genes, and receptors of the vascular endothelial growth factor family of hypoxia-induced angiogenesis molecules is speculated upon, and clinical studies to document these speculations are suggested as well as studies evaluating the potential of laparoscopic PD&W. The usefulness of Argyle chest-tube "venting" and "stenting" by trans-anal passage above colonic "patched" areas as seen in 2 cases is worthy of further study and use.

Pre-term and particularly pre-labor cesarean section to avoid complications of gastroschisis

The marked advantages and merit of pre-term and particularly pre-labor (PTPL) cesarean section (C-section) in the avoidance, and indeed, virtual elimination of severely disabling gastroschisis (GS) complications in infants diagnosed prior to birth by ultrasound has unfortunately remained controversial in the 10 to 12 years since it was first reported and strongly recommended by numerous authors. During this period, GS has remained one of the four major causes of the short-gut syndrome (SGS) in infancy and childhood and a major cause of prolonged, costly, complicated, and hazardous neonatal intensive care unit stays with requirements for total parenteral nutrition (TPN). The most serious and frequent complications of GS in infants born without PTPL C-section are the occurrence of the "peel", which greatly enlarges and rigidifies the eviscerated gut, and of "complicated GS" (intestinal atresia/s, stenosis, necrosis, perforations) (CGS). The "peel" occurs in 100% of these cases and CGS in approximately 20%. "Peel" enlargement and rigidification of eviscerated intestine in the presence of a reduced peritoneal cavity causes great difficulty in covering the eviscerated, enlarged, and rigidified gut with abdominal wall, skin, a prosthesis, etc., and frequently produces gut ischemia from excessive pressure, which may lead to necrotizing enterocolitis (NEC) and SGS as well as prolonged hospital stays. The presence of a "peel" greatly complicates the hazards of dealing with cases of CGS, as resection and anastomosis are virtually impossible in the presence of a "peel." The authors report personal experience with 77 cases of GS dating as far back as 1951; 44 of the infants were born after the onset of labor by vaginal or C-section delivery and all had some degree of "peel" formation. Of 320 cases from the literature (including some of the cases reported here), 61 (19.1%) involved CGS. Of the 33 cases born PT, and especially PL, there were no cases of "peel" and only 1 case of CGS (3.0%). This infant had a single atresia associated with a very small (1 cm) defect in the abdominal wall and no labor-induced "peel," which was easily and successfully repaired by resection and anastomosis. The 6.4-fold reduction in the occurrence of CGS by PTPL C-section (3.0% vs 19.1%) was statistically significant by the chi-square test (P < 0.05), as was the 100% elimination of the disabling "peel." If the single case of CGS associated with a very small defect and no labor or labor-associated "peel" is eliminated, the incidence of CGS in the remaining PTPL group of 32 cases falls to 0 (0% versus 19.1%, P < 0.007). PT and especially PL C-section may be expected to virtually eliminate "peel" formation and CGS and to remove GS as one of the four major causes of SGS. The findings of this report that PT labor prior to PT C-section may result in both "peel" formation and CGS further solidifies the role of labor in the production of both the "peel" and the equally disabling CGS. Failure to appreciate the central role of labor in GS complications has doubtless contributed to the persistent controversy concerning the value and importance of PTPL C-section for gastroschisis diagnosed in utero. The pediatric surgeon has an important responsibility with the obstetrician to monitor the possible occurrence of occult labor in the waning weeks of pregnancy and be prepared to do a prompt C-section if it occurs and there is adequate lung maturity. The achievement of "peel"- and CGS-free gut would greatly facilitate the use of the new Bianchi technique of gut reduction without anesthesia. The combination of the use of epidural anesthesia for the elective PTPL C-section with the Bianchi approach would spare both mother and baby any untoward effects of general anesthesia and present the potential for massive reductions in hospital costs with minimal patient manipulation and disturbance. For infants born with labor-associated "peel," re-evaluation of the suitability and effectiv

Combination of "patch, drain, and wait" and home total parenteral nutrition for midgut volvulus with massive ischemia/necrosis

The successful use of a combination of "patch, drain, and wait" (PDW) and home total parenteral nutrition (TPN) in the management of a case of acute, catastrophic midgut volvulus in a 2-year-11-month-old boy with near-total ischemia/necrosis of his small intestine is reported. The PDW approach to the highly effective management of acute midgut ischemia/necrosis in infancy and childhood (necrotizing enterocolitis and midgut volvulus) involves maximum gut salvage by avoidance of resection, stoma formation, or both through the use of extensive peritoneal cavity drainage by Penrose drains, TPN, and broad-spectrum antibiotics. The extensive peritoneal drainage fosters capture of enteric fistulas with the formation of enterostomies at drain exit sites, while adhesions and ischemia/inflammation-induced hypervascular obliteration of the peritoneal cavity diminish the potential for peritonitis (no peritoneal cavity, no peritonitis) and facilitate impressive salvage of seemingly hopelessly lost ischemic/necrotic gut (a simulation of the in utero ischemic gut process leading to atresias and some varying, but generally mild, gut loss) while simultaneously contributing to the resorption of absolutely non-salvageable gut and the creation of a remarkably clean and adhesion-free peritoneal cavity resembling that of a newborn infant with midgut intestinal atresia.

Metastasis of an intracranial germinoma through a ventriculoperitoneal shunt: recurrence as a yolk-sac tumor

Extraneural metastases of intracranial germinomas, although infrequent, are associated with a generally poor prognosis despite the high radiosensitivity of localized primary tumors. Ventriculoperitoneal shunts have been implicated in facilitating metastatic spread of primary intracranial germinomas. We present a case of a successfully irradiated suprasellar germinoma recurring after 13 months as an intra-abdominal yolk-sac tumor in a young man. The tumor was eradicated with a combination of systemic chemotherapy and local irradiation, with no residual viable tumor cells confirmed at final surgical extirpation. The role of cerebrospinal fluid (CSF) shunts in metastases, mixed germ-cell tumor histology, and tumor markers in recurrences as well as radiation doses and volumes for treating primary tumors are discussed. Systemic chemotherapy may be utilized as prophylaxis against shunt metastases when CSF drainage is necessary.

Omphalomesenteric duct malformations

Omphalomesenteric duct malformations comprise a wide spectrum of anatomic structures and associated symptoms (or no symptoms). They may range from a completely patent omphalomesenteric duct at the umbilicus to a variety of lesser remnants including cysts, fibrous cords connecting the umbilicus to the distal ileum, granulation tissue at the umbilicus, umbilical hernias, and the famous diverticulum of Meckel. Symptoms may involve fecal fistulas at the umbilicus, intussusception/prolapse of ileum at the umbilicus, intestinal obstruction from a variety of causes, melena and anemia, abdominal pain and inflammation, etc. Although symptoms occur most frequently during childhood years (especially in the first 2 years of life), they may occur through adult years as well. Although these malformations are found with equal frequency among the sexes, a significantly greater incidence of symptoms is encountered in males. Although one of the very most frequent malformations to be found (Meckel's diverticulum in 2% to 3% of the population), they are one of the most unlikely to cause symptoms (also Meckel's diverticulum). An awareness of the diversity of these malformations in type and symptomotology is essential to their proper and optimal management.

Possible role of oceanic heat transport in early Eocene climate

Increased oceanic heat transport has often been cited as a means of maintaining warm high-latitude surface temperatures in many intervals of the geologic past, including the early Eocene. Although the excess amount of oceanic heat transport required by warm high latitude sea surface temperatures can be calculated empirically, determining how additional oceanic heat transport would take place has yet to be accomplished. That the mechanisms of enhanced poleward oceanic heat transport remain undefined in paleoclimate reconstructions is an important point that is often overlooked. Using early Eocene climate as an example, we consider various ways to produce enhanced poleward heat transport and latitudinal energy redistribution of the sign and magnitude required by interpreted early Eocene conditions. Our interpolation of early Eocene paleotemperature data indicate that an approximately 30% increase in poleward heat transport would be required to maintain Eocene high-latitude temperatures. This increased heat transport appears difficult to accomplish by any means of ocean circulation if we use present ocean circulation characteristics to evaluate early Eocene rates. Either oceanic processes were very different from those of the present to produce the early Eocene climate conditions or oceanic heat transport was not the primary cause of that climate. We believe that atmospheric processes, with contributions from other factors, such as clouds, were the most likely primary cause of early Eocene climate.

Validity of the Allen Cognitive Levels Assessment: a tri-ethnic comparison

Schizophrenia is a mental illness which is characterized by severe cognitive deficits and impairments in adaptive functioning. The Allen Cognitive Levels (ACL) Assessment is a screening instrument designed to assess cognitive functioning and to aid clinicians in making judgments about how a patient will be able to perform basic activities of daily living. While the ACL has been widely used, the validity of ACL scores for predicting concurrent adaptive functioning has not been established empirically. The present study examined ACL scores in 110 schizophrenic patients. Scores on the ACL were found to be highly related to scores on the Functional Needs Assessment (r = 0.66), which measures a patient's ability to perform basic activities of daily living. Findings provided some of the first strong evidence that ACL scores reflect adaptive functioning. Correlations between the ACL and the Functional Needs Assessment were equally strong in non-Hispanic whites (n = 31, r = 0.67), Mexican-Americans (n = 58, r = 0.60), and African-Americans (n = 21, r = 0.46). Mean scores did not differ between patients from different ethnic groups. In addition, there was no relationship between ACL scores and level of acculturation within the Mexican-American group. Our data strongly support the hypothesis that the ACL provides a valid and culturally unbiased measure of cognitive functioning that can be helpful in determining how a patient is likely to perform activities of daily living.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) distribution and cytochrome P4501A induction in young adult and senescent male mice

While the developmental toxicology of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and its congeners has received considerable attention, the impact of advanced age on the biochemical effects and the pharmacokinetics of dioxins remains largely undetermined. In the present investigation, TCDD tissue distribution and cytochrome P4501A (CYP1A) induction were characterized in male C57BL/6N mice aged 10 weeks and 28 months at 7 days after administration of single oral [3H]TCDD doses ranging from 0.015 to 15 microgram/kg body wt. Determinations of hepatic marker enzyme activities for CYP1A1 (ethoxyresorufin O-deethylation, EROD) and 1A2 (acetanilide-4-hydroxylation, ACOH) indicated that the dose response curves for EROD induction by TCDD were nearly identical for the 2 age groups, but the ACOH induction response was greater in old mice. After receiving the 15 micrograms/kg dose, an increase (approximately 35%) in relative liver weight was observed 7 days after dosing in the 10-week mice, but not in the aged mice, and the hepatic concentration of TCDD was approximately 25% greater in young than old mice. No age difference was found in hepatic nuclear concentrations of TCDD. A dose-dependent increase in liver:fat tissue concentration ratios was noted at both ages, and adipose tissue and blood concentrations of TCDD did not vary significantly with age. In old mice however, TCDD concentrations in skin, kidney and muscle were all approximately twice those of young mice at the 15 micrograms/kg dose. These results suggest that advanced age may have differential effects on Ah receptor-mediated enzyme induction, while increased TCDD concentrations in certain tissues may have toxicological implications for older animals.

Purification and characterization of a multicomponent AP-1.junD complex from T cells. Dependence on a separate cellular factor for enhanced DNA binding activity

TAP-1 (T-cell AP-1) is a previously identified DNA-binding activity that is rapidly induced in activated T cells in the absence of protein synthesis. This activity has been purified over 2,000-fold from the T-cell line MLA144. Purified TAP-1 is a multicomponent complex composed of 38-kDa and 43-kDa junD polypeptides in association with a separate factor(s), distinct from fos, that partly dissociate from the complex during affinity purification but is required for full TAP-1 DNA-binding activity. When reconstituted with TAP-1, this partly dissociated component strongly enhances the DNA-binding activity of the TAP-1 complex. UV-cross-linking analysis identifies the dissociable component of the TAP-1 complex as a separate class of low molecular mass (23-29-kDa) DNA-binding polypeptide(s). 23-29-kDa polypeptides have been partially purified from nuclear extracts derived from MLA144 that enhance TAP-1 DNA-binding activity over 100-fold and increase its contacts with flanking DNA sequence. These results define TAP-1 as a distinct AP-1.junD-containing complex in T cells whose DNA-binding activity is regulated by the interaction of distinct and separate cellular factor(s).

Surveillance of susceptibility testing methodologies for Haemophilus influenzae in Canada, including evaluation of disk diffusion test

We surveyed 75 clinical laboratories to determine if National Committee for Clinical Laboratory Standards (NCCLS) were being used for the susceptibility testing of Haemophilus influenzae. Of the 66 laboratories that performed susceptibility testing, all claimed to follow current NCCLS guidelines. However, upon further questioning, only 23, all of which used disk diffusion testing, accurately interpreted and followed the guidelines. Proficiency testing of 22 of these laboratories found that an unacceptable number of interpretive errors (> 10%) occurred. These results query the merit of routine disk diffusion susceptibility testing of H. influenzae to beta-lactam agents.

Determination of antimicrobial susceptibilities of Canadian isolates of Haemophilus influenzae and characterization of their beta-lactamases. Canadian Haemophilus Study Group

Susceptibility testing of 1,688 Haemophilus influenzae isolates found 484 ampicillin-resistant strains; 474 strains (28.4%) were beta-lactamase positive, and 5 strains (0.4%) were non-beta-lactamase producers. Restriction enzyme digestion of the beta-lactamase amplicon determined that, of 157 strains, 11 (7.0%) contained ROB-1 beta-lactamase and 146 (93.0%) contained a TEM-type beta-lactamase.

Utilization review of the use of BACTEC PLUS high-volume blood culture bottles

The BACTEC PLUS 26 (NR26) (Becton Dickinson, Towson, Md.) high-volume blood culture bottle replaced the less expensive smaller-volume NR6A bottle in our hospital. An audit carried out several months after their introduction revealed that only 17.5% of the NR26 bottles received the required blood volume. Several audits and educational programs were required in order to achieve a compliance rate of > 60%.

Possible methane-induced polar warming in the early Eocene

Reconstructions of early Eocene climate depict a world in which the polar environments support mammals and reptiles, deciduous forests, warm oceans and rare frost conditions. At the same time, tropical sea surface temperatures are interpreted to have been the same as or slightly cooler than present values. The question of how to warm polar regions of Earth without noticeably warming the tropics remains unresolved; increased amounts of greenhouse gases would be expected to warm all latitudes equally. Oceanic heat transport has been postulated as a mechanism for heating high latitudes, but it is difficult to explain the dynamics that would achieve this. Here we consider estimates of Eocene wetland areas and suggest that the flux of methane, an important greenhouse gas, may have been substantially greater during the Eocene than at present. Elevated methane concentrations would have enhanced early Eocene global warming, and also might specifically have prevented severe winter cooling of polar regions because of the potential of atmospheric methane to promote the formation of optically thick, polar stratospheric ice clouds.

Neurovascular immunology: a 25-year odyssey

Small vasoactive neurotransmitter molecules with a long evolutionary history of involvement in biological defense and inflammation play important roles in the up-regulation and down-regulation of the immune response and with similar effects on neuronal and lymphocyte transmembrane signaling molecules and mechanisms. The longest acting of these stimulatory molecules on lymphocyte traffic, substance P and bradykinin, also are transmitters of impulses relating to heat and pain. Heat and pain have been primordial stimuli to learning and memory--immunological as well as CNS.

Atretic, obstructive proximal duodenal mass associated with annular pancreas and malrotation in a newborn male

A case is described of duodenal atresia involving the first portion of the duodenum associated with a partial annular pancreas, complete nonrotation and nonfixation of the intestines, and a congenitally small glottic region in a newborn male. The atretic segment was a 1.3 cm mass adjacent to the pylorus unlike previous reports of duodenal atresia. The diagnosis was delayed for seven days until the child was fed and had bowel movements. Pyloroduodenostomy was performed resulting in cure. An older sibling had a duodenal web requiring previous duodenoduodenostomy.

In vivo influences of phorbol ester and calcium ionophore on lymphocyte traffic, lymph flow and efferent lymph levels of thromboxane B2 in sheep

In vitro systems have provided increasing evidence of significant lymphocyte transmembrane signalling by plasma membrane receptors which utilize antigen and other ligand activation of the inositol phosphate dual second messenger system of intracellular signalling. Elevation of intracellular Ca2+ and activation of protein kinase C are important products of these signals and appear to provide a complete set of mitogenic signals for both T and B cells. Calcium inophore and phorbol ester have been found to mimic these events in vitro and are here employed in vitro to study their effects on lymphocyte traffic and efferent lymph flow through primary peripheral lymph nodes of sheep and on the output into efferent lymph of the arachidonic acid metabolite, thromboxane B2. Calcium ionophore and phorbol ester were given alone or in combination to popliteal lymph nodes of sheep by drainage area injection or by acute infusion into cannulated afferent lympatics of study popliteal lymph nodes whose efferent lymphatic was chronically cannulated for study. The findings resembled those of drainage area immunization with an early increase in efferent lymph flow and prompt and marked depressions in the output into efferent lymph of both small recirculating and blast lymphocytes ('shutdown', 'recruitment'), followed by a marked increase in the output into efferent lymph of both small recirculating and blast lymphocytes. The greatest elevation in both small recirculating and blast lymphocyte outputs was at 24 and 48 h following phorbol ester and calcium ionophore administration. Acute phorbol ester and calcium ionophore administration was associated with a prompt and marked elevation in efferent lymph levels of thromboxane B2 which were of short duration. The findings observed here with lymph node drainage area infusion/injection of both phorbol ester and calcium ionophore are quite similar to those encountered in this sheep lymphocyte traffic model following popliteal lymph node drainage area immunization with killed Salmonella muenchen antigen.

Substance P increases and prolongs increased output of T4 (CD4) lymphocytes from lymph nodes of sheep in vivo: is it a mediator of immunological memory?

There are receptors on lymphocytes for substance P which are found both on small recirculating and on blast lymphocytes. The principal effect of substance P on lymphocytes appears to be a stimulating one, both in vitro and in vivo. The in vivo administration of substance P to sheep by acute infusion into cannulated afferent lymphatics of peripheral lymph nodes has been found to stimulate efferent lymph flow and the output into efferent lymph of both small recirculating and blast lymphocytes. We here report that substance P both enhances and prolongs the enhancement of the output of T4 (CD4) lymphocytes from lymph nodes of sheep in vivo. This output-stimulating effect appears to be specific to T4 (CD4) lymphocytes and is associated with a depressant effect on the output of T8 (CD8) and B lymphocytes. The output-stimulating effect on small T4 (CD4) lymphocytes is quite prolonged, lasting in excess of 96 h after a single 50 micrograms acute infusion. A brief post-infusion depression in T4 (CD4) lymphocyte output is associated with an equally brief, but marked, elevation in the output into efferent lymph of the arachidonic acid metabolite, thromboxane B2. The output-stimulating effect of substance P on blast T lymphocytes is confined to the T4 (CD4) blast lymphocytes. Substance P or a similar molecule may be of value when a specific T4 (CD4) lymphocyte output stimulant effect is desired. A single prior (6 days) acute infusion of substance P into a popliteal lymph node via its cannulated afferent lymphatic produced profound changes in the response to nodal drainage area immunization with killed S. muenchen bacteria. The latent period prior to increased antibody production was abolished, as was the standard post-immunization 'shutdown' period of decreased output of lymphocytes into efferent lymph. These changes were accompanied by a marked and progressive increase in antibody production. The findings reported here suggest substance P-induced long-term potentiation (LTP) of the immune response and raise the question of an involvement of substance P as a major mediator of immunological memory.

On ethylene and stem elongation in green pea seedlings

Maximum elongation of excised internodal stem sections of light-grown pea (Pisum sativum L.) seedlings occurred at 10(-5) molar indoleacetic acid (IAA), with submaximal responses occurring at 10(-4) and 10(-3) molar. Accompanying elongation at concentrations of IAA of 10(-6) to 10(-3) molar was production of ethylene, with the amount increasing up to 10(-4) molar IAA and then becoming nearly constant. Elongation of light-grown sections was not inhibited by exogenous ethylene up to 10,000 ppm in the presence of 10(-5) molar IAA. Marked (up to 50%) inhibition of elongation of internodal segments in situ was observed after treating whole light-grown seedlings with exogenous ethylene for 20 hours. It is concluded that ethylene is not responsible for the submaximal elongation responses of green pea stem sections at high auxin concentrations, but that IAA per se is accountable.

Appendicitis in children aged 13 years and younger

During a recent 4 1/2-year period, an increasing number of young children aged 13 years and younger (230 consecutive patients) came to our institution with signs, symptoms, and findings of acute appendicitis, which was perforated in nearly half of the cases (47%). This was accompanied by a marked increase in the number of very young children aged 6 years and younger (32% of our 230 patients). A prompt response to broad preoperative antibiotic coverage and definitive operative intervention (appendectomy in all cases) was found, with no mortality and essentially no major morbidity (less than 1%). The rapid transition from serious illness to near normalcy in the matter of a few hours with a standardized approach to treatment stimulated this review of appendicitis in this pediatric age group in an effort to define factors influencing these findings.

Recurrent ventriculoperitoneal shunt pseudocyst in a nine-year-old girl

A case of a ventriculoperitoneal shunt pseudocyst in a 9-year-old girl diagnosed using computed tomography is reported. Two attempts at relocation of the shunt failed to prevent reaccumulation of cerebrospinal fluid. A ventriculoatrial shunt was then performed with a successful outcome. Such pseudocysts should be part of the differential diagnosis of abdominal processes in patients with ventriculoperitoneal shunts. If relocation of the shunt outside the pseudocyst is unsuccessful, a ventriculoatrial shunt is generally indicated.

Glass shrapnel injuries to children resulting from "dry ice bomb" explosions: a report of three cases

Glass shrapnel from explosions of "dry ice bombs," created by thrusting dry ice into glass soft-drink bottles and occluding the opening of the bottles, has produced serious and multiple lacerating injuries in three children, which required major operative intervention. We found no previous reports of this grave hazard.

Advantages of performing the sagittal anoplasty operation for imperforate anus at birth

The development of the posterior sagittal anorectoplasty approach has been a major recent advance in the repair of imperforate anus. It has been found that sagittal anoplasty can easily and preferably be carried out in the newborn period without the need for colostomy or "tapering." It is suggested that the perineal sagittal approach be attempted first, with the infant positioned so that the abdominal part of the abdominoperineal approach can be used if necessary--this seldom may be required. Neonatal closure of urinary tract fistulas in boys is an added attractive feature of this approach. The importance of optical magnification (microsurgery) and excellent, intense lighting of the perineal area with a headlamp is stressed for this approach in the newborn, particularly for the management of high pouches and high fistulas. This operation at birth relieves alimentary tract obstruction at birth, eliminates urinary tract contamination (when it exists) at birth, establishes anorectal continuity and maximum potential for "normal" defecation reflexes at birth, and achieves all of this in one rather than three operations.

Colectomy for necrotizing amebic pancolitis in early childhood with survival

A case of necrotizing amebic pancolitis in a 6-year-old boy with asplenia, partial situs inversus, and cyanotic congenital heart disease is reported and the literature is reviewed briefly. Our patient was managed successfully by prompt colectomy, ileostomy, a Stamm gastrostomy, and extensive drainage of the peritoneal cavity with administration of metronidazole postoperatively and prolonged jugular vein Broviac catheter hyperalimentation. This child may be the first survivor of total colonic amebic necrosis in childhood. Necrotizing amebic colitis appears to be more hazardous in infancy and childhood than in adult years. Malnutrition and additional illnesses and malformations may produce greater immunocompromise in the very young, placing them at greater risk for the ultimate of amebic intestinal complications, total colonic necrosis and disintegration.

Substance P increases lymphocyte traffic and lymph flow through peripheral lymph nodes of sheep

Substance P, an 11 amino acid residue vasoactive neurotransmitter peptide, has been found on acute infusion (50 micrograms) into cannulated afferent lymphatics of popliteal lymph nodes of sheep to produce marked elevations in both efferent lymph flow and in the outputs of both blast and small recirculating lymphocytes into popliteal node efferent lymph (chronically cannulated). These elevations were characterized by a delay in the onset of major elevations, a marked prolongation of the elevations and a substantially greater stimulative effect on the output of blast lymphocytes. It is suggested that the number and types of substance P receptors on lymphocytes and in sheep peripheral lymph nodes may be responsible for these observations. Infusion of substance P, known for involvement in pain impulse transmission, was able to briefly overcome anaesthesia-induced depression in lymphocyte traffic. The substance P-induced alterations in lymph flow and lymphocyte traffic in vivo were demonstrated to be due to local rather than systemic effects of substance P.

Prompt elevations of PGE2 and thromboxane A2 metabolites in peripheral node efferent lymph of sheep following drainage area immunization

In the past decade, the main interest in the involvement of prostaglandin E2 (PGE2) in the immune response has been concerned with its role in immunomodulation (suppression) both in vitro and in vivo. Comparatively little attention has been devoted to its immunostimulatory role. It has been suggested that PGE2, like histamine, may function as a 'double agent', initially triggering, facilitating and augmenting a stimulatory immune response and later modulating, limiting and contributing to the turning off of this response. We here report an early (within minutes) immunostimulatory involvement of PGE2 (and thromboxane A2) in the sheep, with prompt elevations in levels of PGE2 and thromboxane B2 in popliteal lymph node efferent lymph following drainage area immunization with killed Salmonella muenchen bacteria. These elevations were associated with an increase in efferent lymph flow and an equally prompt but limited depression of lymphocyte outputs into efferent lymph ('shutdown', 'recruitment'). Local increases in blood flow and vascular permeability probably play important roles in these events.

Malignant hyperthermia: experience in the prospective management of eight children

Malignant hyperthermia (MH) is a seemingly rare genetic myopathy. Hypermetabolic crisis accompanied by a rise in body temperature to as high as 44 degrees C, is its hallmark. Malignant hyperthermia is usually triggered by potent inhalation anesthetics and/or depolarizing muscle relaxants. Because of the extraordinary incidence of death in patients who are at risk, pediatric surgeons may be reluctant to operate on these patients. Eight such patients were referred to the Pediatric Surgery Service and the UCLA Malignant Hyperthermia Center following pediatric surgical procedures aborted for first episodes of malignant hyperthermia (five) or for a strong family history of malignant hyperthermia (three). They were anesthetized with nitrous oxide, barbiturates, opiates, tranquilizers, and nondepolarizing muscle relaxants. The patients were not treated prophylactically with dantrolene. Cardiac monitoring, end-tidal PCO2, and rectal temperatures were monitored. After completion of their pediatric surgical procedures, all eight patients had a vastus lateralis muscle biopsy performed and subsequent caffeine/halothane contracture studies completed. The contracture study result was positive in all patients studied. No anesthetic or surgical complications were encountered. This study shows that patients at risk for developing MH crisis can have pediatric surgical procedures performed safely with appropriately selected general anesthesia.

In vivo depression of lymphocyte traffic in sheep by VIP and HIV (AIDS)-related peptides

Core pentapeptides and an octapeptide (Peptide T) computer deduced from amino acid sequences from vasoactive intestinal peptide (VIP) and the 120 gp external envelope of the HIV (AIDS) virus and synthesized have been reported to have important in vitro and in vivo activity including inhibition of HIV binding to CD4 surface antigens of brain cells and lymphocytes and limitation of HIV infectivity. Two of these core pentapeptides, peptide TTNYT (Peptide T [4-8]) and peptide TDNYT (VIP [7-11]), are reported here, on acute infusion into cannulated afferent popliteal lymphatics of sheep, to produce prompt and marked depressions in the output of both small recirculating and blast lymphocytes into popliteal lymph node efferent lymph. As with a prior VIP infusion study, there appeared to be a selective effect on T4 (CD4) lymphocytes, with a marked predominance of T4 (CD4) lymphocytes in the lymphocyte depleted efferent lymph.

Massive acquired omental cyst as a complication of ventriculo-peritoneal shunting

A case of massive acquired omental cyst in a 13-year-old girl as a complication of ventriculo-peritoneal (VP) shunting is reported. This is the first such case to be reported. Most complications of VP shunting involve shunt blockade, infection, or both. The absence of shunt blockade, infection or inflammation, and associated symptoms in this case permitted the acquired omental cyst to reach a massive size before detection; the cyst was managed successfully by simple resection of a large part of its thin wall.

Depression of lymphocyte traffic in sheep by vasoactive intestinal peptide (VIP)

Vasoactive intestinal peptide (VIP) is a 28 amino acid-residue neurovascular and gut peptide with a number of important biological activities. Recent in vitro studies suggest an immunomodulatory (depressant) role for VIP. In the present in vivo studies, employing the Hall and Morris sheep lymphocyte traffic model, acute infusions of VIP into cannulated afferent lymphatics of popliteal lymph nodes produced prompt and marked depressions in the output of both small recirculating and blast lymphocytes into popliteal efferent lymph, with a selective effect on T4 (CD4) lymphocytes. It has been suggested that the HIV (AIDS) virus may employ VIP or VIP-like receptors on brain cells and lymphocytes for intracellular access.

Depression of lymphocyte traffic in sheep by anaesthesia and associated changes in efferent-lymph PGE2 and antibody levels

General anaesthesia of sheep with ketamine and xylazine has been found to produce a profound and prolonged depression in lymphocyte traffic through primary peripheral lymph nodes, as mirrored in the output of lymphocytes into efferent lymph. In this study, the depression has been found to be associated with a marked and sustained elevation in prostaglandin E2 (PGE2) levels in efferent lymph. The degree and duration of lymphocyte output depression was found to be modulated (diminished), both in degree and duration, by study-node drainage-area stimulation from prior surgery, inflammation or bacterial immunization. Even when the anaesthesia-associated lymphocyte-output depression was modulated by drainage-area inflammation, the period of lymphocyte-output depression was correlated still with elevated levels of PGE2 in efferent lymph. When drainage-area stimulation was produced by bacterial immunization (killed Salmonella muenchen), the anaesthesia-associated depression in lymphocyte output into efferent lymph (small as well as blast) was accompanied by a depression in antibody output into efferent lymph.

Increased outputs of lymphocytes in lymph efferent from the lymph nodes of sheep during systemic arterial hypertension induced by phenylephrine or dopamine

Induced systemic arterial hypotension by intravenous nitroprusside administration and by acute arterial occlusion in sheep have been found to reduce lymphocyte traffic as mirrored in the output of lymphocytes into the efferent lymph of peripheral lymph nodes. In the present series of experiments in sheep with chronically cannulated efferent lymphatics of peripheral lymph nodes, induced and monitored systemic arterial hypertension with intravenous pump infusions of phenylephrine or dopamine both produced sharp increases in the output of lymphocytes into efferent lymph in all of 27 studies. The increases in lymphocyte output with dopamine were more sustained and less associated with evidence of lymphoid tissue damage than with phenylephrine. Phenylephrine infusions were attended by a high incidence of gross bleeding into the efferent lymph, of increased coagulability of efferent lymph in the absence of gross bleeding and of prolonged depression of lymphocyte outputs after the cessation of intravenous infusion.