Induction of interleukin 6 (IL-6) by hypoxia in vascular cells. Central role of the binding site for nuclear factor-IL-6

The pathologic picture in ischemic tissue injury shares features with the inflammatory response, including production of proinflammatory cytokines. Hypoxia-mediated induction of interleukin-6 (IL-6), a cytokine with anti-inflammatory properties, could set in motion mechanisms limiting inflammation in ischemia. Exposure of cultured endothelial cells (ECs) to H (pO2 approximately 12-16 torr) increased transcription of IL-6, elevated levels of IL-6 mRNA, and induced elaboration of IL-6 antigen in a time-dependent manner. Exposure of mice to hypoxia increased IL-6 transcripts in the lung, and immunostaining revealed a striking increase in IL-6 antigen in pulmonary vasculature. Transfection of ECs with deletion chimeric IL-6 promoter-chloramphenicol acetyl-transferase (CAT) constructs showed hypoxia-mediated 9-11-fold induction with -1200/+13, -596/+13, and -225/+13 but no induction with -111/+13. Electrophoretic mobility shift assays (EMSAs) using -225/-111 as the labeled probe demonstrated enhanced binding activity in nuclear extracts of hypoxic ECs and lung; the appearance of the gel shift band was prevented by excess unlabeled probe (-225/-111), and hypoxia-mediated enhancement of the band was blocked by a probe corresponding to the nuclear factor (NF)-IL-6 site (-158/-145). The hypoxia-enhanced band on EMSA displayed a supershift with antibody to CCAAT-enhancer-binding protein beta (C/EBP-beta), but antibody to C/EBP-alpha or -delta was without effect. Transfection of ECs with a construct comprising thymidine kinase promoter, -225/-111 in either the 5' to 3' to 5' orientation, and the reporter CAT showed this region to be an enhancer (approximately 8-fold) under hypoxia. EMSA with the NF-IL-6 probe revealed a prominent induction of binding activity with nuclear extracts from hypoxic ECs and whole lung. Constructs with -158/-145 and the CAT reporter gene showed induction when transfected into hypoxic ECs, whereas a similar construct with the NF-IL-6 motif mutationally inactivated failed to display hypoxia-induced expression. Furthermore, the tumor necrosis factor (TNF) gene, whose product contributes to ischemic pathology and contains a putative regulatory NF-IL-6 site, demonstrated enhanced binding activity for its NF-IL-6 motif and induction of TNF mRNA based on analysis of hypoxic lung. These data indicate that hypoxia induces expression of IL-6, most likely a result of hypoxic activation at the NF-IL-6 site, and suggest that other genes with regulatory NF-IL-6 sites may also be induced by a similar mechanism.

Undernutrition and the development of brain neurotransmitter systems

While there are homeostatic mechanisms to protect the brain against wide fluctuations in the availability of essential nutrients, food deprivation is known to influence brain neurochemistry. Given the growing problem of infant undernutrition and the fact that the developing nervous system appears to be especially vulnerable to this type of insult, numerous studies have been conducted to define the relationship between nutritional factors and cellular growth and maturation in the brain. The data suggest that the development of both neural and nonneural elements are significantly affected by undernutrition. This includes processes and substances important for neurotransmission such as transmitter synthesis, degradation and receptor sites. Because many neuropsychiatric conditions can be traced to dysfunctions in synaptic neurochemistry, it is possible that some of the central nervous system abnormalities which result from childhood undernutrition may be a consequence of a modification in synaptic biochemistry. The present report reviews data relating to this issue with the aim of assessing its relevance to developmental neurobiology.

Further studies on adrenarche in nonhuman primates

Serum concentrations of dehydroepiandrosterone (DHA), DHA sulfate, and cortisol were measured in 52 chimpanzees (aged 0.5--10 yr), 76 Macaca mulatta (aged 0.25--5 yr), and 80 Macaca nemestrina (aged 0.5--9 yr). Sexual maturation was assessed by age and by the presence of menarche or the appearance of perineal turgescence in the females and by measurement of serum testosterone in the males. In an additional group of 10 young adult female M. mulatta, four repeated determinations of these same steroids at 30-min intervals demonstrated that the stress of capture and venipuncture caused a significant rise in serum levels of not only cortisol but also of DHA and DHA sulfate. The chimpanzees demonstrated an age-related rise in serum concentrations of DHA and DHA sulfate relative to cortisol which began before the onset of puberty and thus closely resembled human adrenarche. In M. mulatta, serum DHA levels showed no change with age, while DHA sulfate values decreased progressively both before and during puberty. The pattern in M. nemestrina was similar, with stable DHA and declining DHA sulfate levels before and during puberty. However, in the oldest group (aged 6--9 yr) of mature M. nemestrina, there was a significant postpubertal rise of both DHA and DHA sulfate with no change in serum cortisol. These data suggest that monkeys, just as higher primates, may show increasing adrenal secretion of C19 steroids at around 6--9 yr. This adrenarchal process appears to be completely independent of sexual maturation and probably merely reflects the influence of progressive adrenal growth and the resulting impact of changing intraadrenal steroid concentrations upon steroidogenesis in the zona reticularis.

Immunohistochemical localization of extracellular matrix proteins in human glioma, both in vivo and in vitro

Expression of type IV collagen, fibronectin and laminin in various types of primary human brain tumor sections and normal brain tissue sections as well as cultured glioma cell lines was examined by an immunofluorescence technique. Type IV collagen, fibronectin, and laminin were mainly localized to the basement membrane of the vasculature in glioblastoma, anaplastic astrocytoma, low grade glioma, and in normal brain. However, positive staining for all the extracellular matrix (ECM) components tested was found only in glioblastoma sections both in the cells and in the ECM. In all other tumor types and in normal brain tissue, the cells did not stain for any of the ECM components. Four glioblastoma cell lines and autologous ECM synthesized by respective glioblastoma cell lines also showed positive staining for type IV collagen, fibronectin and laminin in vitro. These results suggest that glioblastoma cells both in vitro and in vivo express the extracellular matrix components that are involved in the regulation of tumor cell invasion.

Glioblastoma stem cells exploit the αvβ8 integrin-TGFβ1 signaling axis to drive tumor initiation and progression

Glioblastoma (GBM) is a primary brain cancer that contains populations of stem-like cancer cells (GSCs) that home to specialized perivascular niches. GSC interactions with their niche influence self-renewal, differentiation and drug resistance, although the pathways underlying these events remain largely unknown. Here, we report that the integrin αvβ8 and its latent transforming growth factor β1 (TGFβ1) protein ligand have central roles in promoting niche co-option and GBM initiation. αvβ8 integrin is highly expressed in GSCs and is essential for self-renewal and lineage commitment in vitro. Fractionation of β8^high cells from freshly resected human GBM samples also reveals a requirement for this integrin in tumorigenesis in vivo. Whole-transcriptome sequencing reveals that αvβ8 integrin regulates tumor development, in part, by driving TGFβ1-induced DNA replication and mitotic checkpoint progression. Collectively, these data identify the αvβ8 integrin-TGFβ1 signaling axis as crucial for exploitation of the perivascular niche and identify potential therapeutic targets for inhibiting tumor growth and progression in patients with GBM.

The DiPEP study: an observational study of the diagnostic accuracy of clinical assessment, D-dimer and chest x-ray for suspected pulmonary embolism in pregnancy and postpartum

Objective

To identify clinical features associated with pulmonary embolism (PE) diagnosis and determine the accuracy of decision rules and D‐dimer for diagnosing suspected PE in pregnant/postpartum women

Design

Observational cohort study augmented with additional cases.

Setting

Emergency departments and maternity units at eleven prospectively recruiting sites and maternity units in the United Kingdom Obstetric Surveillance System (UKOSS)

Population

324 pregnant/postpartum women with suspected PE and 198 pregnant/postpartum women with diagnosed PE

Methods

We recorded clinical features, elements of clinical decision rules, D‐dimer measurements, imaging results, treatments and adverse outcomes up to 30 days

Main outcome measures

Women were classified as having PE on the basis of imaging, treatment and adverse outcomes by assessors blind to clinical features and D‐dimer. Primary analysis was limited to women with conclusive imaging to avoid work‐up bias. Secondary analyses included women with clinically diagnosed or ruled out PE.

Results

The only clinical features associated with PE on multivariate analysis were age (odds ratio 1.06; 95% confidence interval 1.01–1.11), previous thrombosis (3.07; 1.05–8.99), family history of thrombosis (0.35; 0.14–0.90), temperature (2.22; 1.26–3.91), systolic blood pressure (0.96; 0.93–0.99), oxygen saturation (0.87; 0.78–0.97) and PE‐related chest x‐ray abnormality (13.4; 1.39–130.2). Clinical decision rules had areas under the receiver‐operator characteristic curve ranging from 0.577 to 0.732 and no clinically useful threshold for decision‐making. Sensitivities and specificities of D‐dimer were 88.4% and 8.8% using a standard threshold and 69.8% and 32.8% using a pregnancy‐specific threshold.

Conclusions

Clinical decision rules and D‐dimer should not be used to select pregnant or postpartum women with suspected PE for further investigation. Clinical features and chest x‐ray appearances may have counter‐intuitive associations with PE in this context.

Tweetable abstract

Clinical decision rules and D‐dimer are not helpful for diagnosing pregnant/postpartum women with suspected PE

Clinical decision rules and D‐dimer are not helpful for diagnosing pregnant/postpartum women with suspected PE.

Kainate receptors activate NF-kappaB via MAP kinase in striatal neurones

The transcription factor NF-kappaB has been implicated in the synaptic plasticity and neurotoxicity mediated by ionotropic glutamate receptors in the striatum. However, the class of glutamate receptor and the intracellular pathways involved have not been determined. Kainate, but not AMPA or NMDA, was found to activate NF-kappaB in superfused slices of rat striatum. A similar activation was produced by the calcium ionophore A23187. The NF-kappaB activation by kainate was not observed in the absence of extracellular calcium, and was blocked by the p44/p42 MAP kinase inhibitor PD98059, but not by the p38 MAP kinase inhibitor SB203580. This demonstrates that striatal kainate receptors are coupled to NF-kappaB activation via calcium influx and p44/p42 MAP kinase activation.

Activation of p44/p42 MAP kinase in striatal neurons via kainate receptors and PI3 kinase

The members of the mitogen-activated protein (MAP) kinase family -- p44/p42 MAP kinase (ERK), c-jun N-terminal kinase (JNK) and p38 MAP kinase (p38) are known to be important mediators of the physiological plasticity or neurotoxicity induced in the striatum by activation of ionotropic glutamate receptors. However, our knowledge of the class of glutamate receptor and the intracellular pathways involved derives totally from studies on embryonic neurons, where the mechanisms are likely to be totally different from those operating in mature neurons. In superfused striatal slices from adult rats, NMDA and kainate, but not AMPA, were found to activate ERK. No activation of p38 or JNK was detected following treatment with any ionotropic glutamate receptor agonist. The activation of ERK by kainate was blocked by the ERK kinase (MEK) inhibitor PD98059, and the PI3 kinase inhibitor wortmannin, but not by the p38 MAP kinase inhibitor SB203580. This provides evidence for a novel pathway linking striatal kainate receptors to ERK activation via PI3 kinase and MEK.

Expression and role of matrix metalloproteinases MMP-2 and MMP-9 in human spinal column tumors

Matrix metalloproteinases (MMPs) have been implicated in the process of tumor invasion and metastasis formation. Thus, we determined the expression of MMPs in various primary and metastatic spinal tumors in order to assess the role of these enzymes in spinal invasion. MMP expression was examined by immunohistochemical localization, and quantitative evaluation of MMP protein content was determined by enzyme-linked immunosorbant assay (ELISA) and Western blotting. MMP enzyme activity was determined by gelatin zymography. Lung carcinomas and melanomas metastatic to the spine were shown to have higher levels of MMP-9 activity than those of breast, thyroid, renal metastases and primary spinal tumors. Immunohistochemical analysis revealed similar difference in expression of MMP-9 in tissue samples. When the tissue samples were subjected to gelatin zymography for examination of MMP-2 and MMP-9 activity and to ELISA and Western blotting for quantitative estimation of protein content, the most striking results were obtained for lung carcinomas and melanomas relative to the other tumors. Lung carcinomas and melanomas metastatic to the spine had considerably higher levels of MMP-9 activity than those of primary spinal tumor or breast, thyroid, and renal carcinoma metastases. Within the metastatic tumor category, neoplasms that are known to be associated with the shortest overall survival rates and most aggressive behavior, such as lung carcinomas and melanomas, had the highest levels of MMP-2 and MMP-9 activity compared to those less aggressive metastatic tumors such as breast, renal cell, and thyroid carcinomas. Our results suggest that MMPs may contribute to the metastases to the spinal column, and overexpression of these enzymes may correlate with enhanced invasive properties of both primary and metastatic spinal tumors.

Influence of restraint and ketamine anesthesia on adrenal steroids, progesterone, and gonadotropins in rhesus monkeys

Changes in gonadotropins, progesterone, cortisol, DHA, and DHAS were monitored in 10 female rhesus monkeys (Days 20-23 of the menstrual cycle) subjected to cage restraint with or without ketamine anesthesia for successive venipunctures. All animals were bled without sedation for 2 hr at 30-min intervals. Then 4 of the animals were anesthetized with ketamine-HCl and bleedings in all animals were continued for an additional 2.5 hr. FSH and progesterone were not appreciably affected by either restraint technique. LH declined steadily for the duration of the bleedings (P less than 0.05). Serum levels of cortisol and the adrenal androgens increased twofold (P less than 0.05). Anesthesia with ketamine had no effect on any of the six variables when compared with saline controls. Cortisol and dehydroepiandrosterone (DHA) levels tended to plateau (P less than 0.01) after 2 hr in both treated and control groups. In contrast, dehydroepiandrosterone sulfate (DHAS) levels increased continuously throughout the entire study period. These data indicate that ketamine anesthesia does not alter endocrine responses to venipuncture when administered following cage restraint of conscious animals. These findings further confirm the difficulties in obtaining estimates of basal levels of hormones which are responsive to stress and suggest that the first sample may provide the best estimate.

Differences in levels of parental stress among mothers of learning disabled, emotionally impaired, and regular school children

This study examined the stress among mothers of children in regular and special education. The sample of 45 mothers had children enrolled in public schools from Kindergarten to Grade 8. To three groups, Group 1 of mothers with children in regular education, Group 2 of mothers with children classified as learning disabled, and Group 3 of mothers with children classified as emotionally impaired, the Parenting Stress Index was given to examine whether differences in stress among groups were significant. An analysis of variance and Tukey's HSD indicated significant differences in the Child Domain and on certain child subscales (Acceptability, Mood, Distractibility, Reinforcement), with Group 3 scoring significantly higher than Group 1. Groups 2 and 3 scored significantly higher on the Total Child Domain than Group 1. Group 3 also scored higher than Group 1 on the Parent Domain and on the sum of both domains.

A comparison of pneumonia caused by gentamicin, methicillin-resistant and gentamicin, methicillin-sensitive Staphylococcus aureus: epidemiologic and clinical studies

We investigated an outbreak of nosocomial pneumonia due to gentamicin, methicillin-resistant Staphylococcus aureus (GMRSA). We compared the predisposing factors for pneumonia due to GMRSA to those for pneumonia due to gentamicin, methicillin-sensitive Staphylococcus aureus (GMSSA). Seventeen of 29 patients with staphylococcal pneumonia were infected with GMRSA. Risk factors and associated diseases which selected for infection with GMRSA as opposed to GMSSA included prior antibiotic therapy for a prolonged period of time (p = 0.0001), number of risk factors per patient (p = 0.0001), days hospitalized prior to diagnosis of pneumonia (p = 0.002) and number of associated diseases per patient (p = 0.002). Despite the epidemiologic differences between GMSSA and GMRSA pneumonia, there were no differences in the clinical presentation, course of illness, complications, response to appropriate therapy or outcome between the two groups. Survival was adversely affected by age only among the GMSSA patients (p = 0.02) and by the number of associated diseases (p = 0.005).

Effects of naloxone and an enkephalin analog on serum prolactin, cortisol, and gonadotropins in the chimpanzee

To assess a possible regulatory influence of opioids upon anterior pituitary function in the chimpanzee, we evaluated the effects of the specific opiate receptor antagonist naloxone and the agonistic enkephalin analog [D-Ala2, MePhe4,Met(o)-ol]enkephalin (FK 33-824; Sandoz) on serum levels of PRL, cortisol, FSH, and LH. Under ketamine anesthesia, the following were administered by iv injection during the early follicular phase of successive menstrual cycles in nine female chimpanzees: naloxone (10 mg; n = 7) or saline vehicle (n = 7) randomly assigned in the first two cycles, FK 33-824 0.25 mg (n = 3) in the third cycle, FK 33-824 0.50 mg (n = 4) in the fourth cycle, and FK 33-824 (0.50 mg) immediately preceded by naloxone (10 mg; n = 4) in the last cycle. Five pretreatment and 12 posttreatment serum samples were obtained at 10- to 15-min intervals for subsequent RIA. Naloxone caused a significant reduction in PRL levels from a pretreatment mean of 29.3 ng/ml to a mean of 11.1 ng/ml at 180 min. Values from 60-180 min were significantly below the saline control group at comparable times. A dose-related increment in PRL levels was seen after FK 33-824 administration, with mean peak values at 30 min of 61.0 and 92.3 ng/ml after the low and high doses, respectively. Naloxone pretreatment markedly attenuated the response to high dose FK 33-824. Cortisol levels rose in all groups throughout the study period, a presumed effect of the ketamine anesthesia. Compared to the saline group, no effects of FK 33-824 were observed. Naloxone, given alone or with FK 33-824, had a small, but significant, stimulatory effect on cortisol from 60-120 min posttreatment compared to the control group. Naloxone caused a significant increment in LH levels from a pretreatment mean of 11.7 micrograms/dl to a peak of 19.1 micrograms/dl at 30 min and in FSH level from 33.2 micrograms/dl before therapy to 40.0 micrograms/dl at 45 min. There was no influence of FK 33-824 on gonadotropin levels, although the high dose did blunt the response to naloxone. Taken together, these effects suggest that opiate agonists and endogenous opioid pathways may modulate anterior pituitary function in the chimpanzee, as in man.

Food value of red tide (Gonyaulax polyedra)

Two harvests of ocean-growing red tide, comprised mainly of Gonyaulax polyedra, were evaluated in limited trials of rat feeding. The protein of red tide (25 to 30 percent, dry basis) supported growth satisfactorily. The essential amino acid composition of the protein closely resembles that of casein, the major protein of milk. As a marine resource, plankton represents a challenge for research.

Equivalent potency and pharmacokinetics of recombinant human growth hormones with or without an N-terminal methionine

Two forms of human GH (hGH) have been produced by recombinant DNA technology. One form has an amino acid sequence identical to that of the natural pituitary hormone (rhGH) and the other form has an additional N-terminal methionine (Met-hGH). The biological potencies of these 2 polypeptides have been compared in hypophysectomized rats in a multidose study measuring body weights and several long bone growth parameters. The pharmacokinetic profiles after iv and sc injection were determined in cynomolgus monkeys in a 4-period cross-over study. All of the measured parameters in all the studies indicated that there was no difference in the two forms of hGH. Measurements taken after 27 daily injections of rhGH or Met-hGH (30-500 micrograms/kg.day) indicated that femur length and width of the proliferative zone in the tibial epiphysis showed dose-related effects for both forms of hGH but no difference between them. The relative potency, based on body weight gain, was calculated using a parallel line bioassay. Weight gain after 8 daily injections in the 5-dose long bone growth study indicated a rhGH potency of 0.80 (95% confidence interval, 0.5-1.23) relative to Met-hGH. It was concluded that the presence of an N-terminal methionine on hGH has no effect on potency in this model. The pharmacokinetic parameters after iv administration were estimated by fitting serum concentration-time data to a 2-compartment model. Parameters after sc injection were computed by compartment-independent methods. Met-hGH and rhGH had very similar pharmacokinetic profiles after both routes of administration. Comparison of the pharmacokinetic parameters indicated that the clearance after iv administration (rhGH, 15 ml/min; Met-hGH, 13 ml/min) and the sc bioavailability (rhGH, 0.72 +/- 0.21; Met-hGH, 0.59 +/- 0.21) were not significantly different for the 2 forms of hGH. It was concluded that rhGH and Met-hGH have equivalent bioavailability and pharmacokinetics in cynomolgus monkeys.

Early undernutrition and [3H]gamma-aminobutyric acid binding in rat brain

The effect of early undernutrition and dietary rehabilitation on [3H]gamma-aminobutyric acid ([3H]GABA) binding in rat brain cerebral cortex and hippocampus was examined. Undernourished animals were obtained by exposing their mothers to a protein-deficient diet during both gestation and lactation. Saturation analysis of [3H]GABA binding in the cerebral cortex and hippocampus revealed high- and low-affinity components in the undernourished group, whereas control animals possessed only a low-affinity site. The concentration of low-affinity binding sites was greater in the undernourished animals. Rehabilitation of undernourished animals completely abolished the binding site differences. Treatment of brain membranes with Triton X-100 yielded two binding components in both the undernourished and control animals, although the concentration of lower affinity sites was still greater in the undernourished group. Neither the efficacy nor the potency of GABA to activate benzodiazepine binding in cerebral cortex was modified by undernutrition. These data suggest that early undernourishment modifies the characteristics of [3H]GABA binding, perhaps by reducing the brain content of endogenous inhibitors of the higher affinity binding site. The lack of effect on GABA-activated benzodiazepine binding suggests the possibility that neither the high- nor the low-affinity GABA binding sites are coupled to this receptor component.

Discriminant function analysis of LD/BD children scores on the WISC-R

Investigated the performance of learning-disabled (LD) and behavior-disorder (BD) children and youth on the WISC-R. A stepwise discriminant function analysis and chi-square analysis were used to analyze the performance of 135 children and youth (83 males, 52 females) on the WISC-R. The sample consisted of 68 LD and 67 BD Ss, whose ages ranged from 81-1 month to 168-6 months with a mean age of 123-1 months. Results suggest that discriminant function analysis can be useful as one criterion in differentiating LD children from BD children. Implications are discussed.