A neural basis for general intelligence

Universal positive correlations between different cognitive tests motivate the concept of "general intelligence" or Spearman's g. Here the neural basis for g is investigated by means of positron emission tomography. Spatial, verbal, and perceptuo-motor tasks with high-g involvement are compared with matched low-g control tasks. In contrast to the common view that g reflects a broad sample of major cognitive functions, high-g tasks do not show diffuse recruitment of multiple brain regions. Instead they are associated with selective recruitment of lateral frontal cortex in one or both hemispheres. Despite very different task content in the three high-g-low-g contrasts, lateral frontal recruitment is markedly similar in each case. Many previous experiments have shown these same frontal regions to be recruited by a broad range of different cognitive demands. The results suggest that "general intelligence" derives from a specific frontal system important in the control of diverse forms of behavior.

Cutaneous T-cell lymphomas: the Sézary syndrome, mycosis fungoides, and related disorders

Substantial evidence has accumulated to indicate not only that mycosis fungoides and the Sézary syndrome are closely related malignancies, but to suggest that they are part of a larger spectrum of cutaneous lymphomas. The neoplastic cells of these disorders have membrane features of thymus-derived (T) lymphocytes, a characteristic tissue distribution (skin infiltration, marrow sparing, localization in T-cell regions of lymphoid tissue), and distinctive morphology. For these reasons, we suggest that these lymphoproliferative disorders be grouped together as "cutaneous T-cell lymphomas". The anergy noted in patients of this group with leukemia probably is related to both decreased percentages of normal T cells and presence in the serum of macrophage migration inhibitory activity. Leukapheresis has been particularly effective in the management of selected patients. The homogeneous T-cell populations in the patients with leukemia also provide important opportunities to study many aspects of lymphocyte physiology that are of broad biologic significance.

Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours (NETs)

These guidelines update previous guidance published in 2005. They have been revised by a group who are members of the UK and Ireland Neuroendocrine Tumour Society with endorsement from the clinical committees of the British Society of Gastroenterology, the Society for Endocrinology, the Association of Surgeons of Great Britain and Ireland (and its Surgical Specialty Associations), the British Society of Gastrointestinal and Abdominal Radiology and others. The authorship represents leaders of the various groups in the UK and Ireland Neuroendocrine Tumour Society, but a large amount of work has been carried out by other specialists, many of whom attended a guidelines conference in May 2009. We have attempted to represent this work in the acknowledgements section. Over the past few years, there have been advances in the management of neuroendocrine tumours, which have included clearer characterisation, more specific and therapeutically relevant diagnosis, and improved treatments. However, there remain few randomised trials in the field and the disease is uncommon, hence all evidence must be considered weak in comparison with other more common cancers.

Hematological characterization of congenital osteopetrosis in op/op mouse. Possible mechanism for abnormal macrophage differentiation

Compared with normal littermates, the op/op mice had very few macrophages in the peritoneal cavity and severely reduced numbers of monocytes in the peripheral blood. Moreover, osteopetrotic animals demonstrated an altered distribution of hemopoietic tissue with a 10-fold decrease in the number of marrow cells. Liver hemopoiesis persisted in 4-wk-old mice as evidenced by the presence of hemopoietic stem cells (HSC). Moreover, the concentration of HSC was decreased in marrow and increased in the spleen of op/op mice. In spite of the paucity of cells of monocyte-macrophage lineage in vivo, progenitor cells from hemopoietic tissues of op/op mice formed increased numbers of monocyte-macrophage colonies in vitro in the presence of exogenous colony-stimulating activity (CSA). The source of this critical CSA was a medium conditioned by stromal fibroblastoid colonies formed in vitro by normal marrow cells. Therefore, these data suggest that op/op mice possess normal monocyte-macrophage-osteoclast progenitor cells but these cells are unable to fully differentiate in the op/op mouse microenvironment. In support of this, in cultures of stromal fibroblastoid colonies from op/op marrow or spleen, the concomitant growth of macrophages, normally very dense, was drastically reduced. Moreover, transplantation of op/op spleen cells into lethally irradiated littermate recipients resulted in their hemopoietic reconstitution without signs of macrophage defect. Thus, the op/op splenic cells do not transfer the disease and are capable of normal differentiation in normal in vivo environment. These observations support the hypothesis that the defect in op/op mice is a result of the failure of hemopoietic stromal fibroblastoid cells to release sufficient amounts of CSA necessary for normal differentiation of cells of the monocyte-macrophage lineage.

Regulation of placental vascular endothelial growth factor (VEGF) and placenta growth factor (PIGF) and soluble Flt-1 by oxygen--a review

Morphological studies show poor placental vascular development and an increase in the mitotic index of cytotrophoblast cells in intrauterine growth restriction (IUGR). We hypothesized that the reported relatively high oxygen level in the intervillous space in contact with IUGR placental villi will limit angiogenesis by changes in vascular endothelial growth factor (VEGF) and placenta growth factor (PIGF) expression and function. Western immunoblot analysis demonstrates a diametric expression of PIGF and VEGF proteins throughout pregnancy, with P1GF levels increasing and VEGF levels decreasing, consistent with placental oxygenation. PIGF mRNA and protein is increased in IUGR as compared to gestationally matched normal placentae. Increasing oxygen tension upregulates P1GF protein in term placental villous explants, whereas hypoxia downregulates P1GF and VEGFR-1 (Flt-1) autophosphorylation in term trophoblast choriocarcinoma cell line (BeWo). Levels of soluble Flt-1 (sFlt-1) protein in supernatant of term villous explants were upregulated by 1 per cent hypoxia, whereas hyperoxia (40 per cent) decreased sFlt-1 levels, indicating that under conditions of increasing oxygen tension, PlGF function may remain unopposed. The addition of PlGF-1 to a spontaneously transformed first trimester cytotrophoblast cell line (ED27) stimulated cell proliferation while PlGF-2 had little effect. In contrast, the addition of PlGF-1 had little effect on endothelial cell proliferation while this was inhibited by PIGF-2. Taken together these changes provide a molecular explanation for the observed poor angiogenesis in the pathogenesis of IUGR.

Etiology and treatment of community-acquired pneumonia in ambulatory children

OBJECTIVES

To determine the etiology of community-acquired pneumonia in ambulatory children and to compare responses to treatment with azithromycin, amoxicillin-clavulanate or erythromycin estolate.

METHODS

Ambulatory patients with pneumonia were identified at the Children's Medical Center of Dallas, TX. Children age 6 months to 16 years with radiographic and clinical evidence of pneumonia were enrolled and randomized to receive either azithromycin suspension for 5 days or a 10-day course of amoxicillin-clavulanate for those <5 years or erythromycin estolate suspension for those > or = 5 years. Blood culture was obtained in all patients and we obtained nasopharyngeal and pharyngeal swabs for culture and polymerase chain reaction (PCR) testing for Chlamydia pneumoniae and Mycoplasma pneumoniae and nasopharyngeal swabs for viral direct fluorescent antibody and culture. Acute and convalescent serum specimens were tested for antibodies to C. pneumoniae, M. pneumoniae and Streptococcus pneumoniae. Patients were evaluated 10 to 37 days later when repeat specimens for serology, PCR and culture were obtained. For comparative purposes healthy children attending the well-child clinic had nasopharyngeal and pharyngeal swabs obtained for PCR and culture for C. pneumoniae and M. pneumoniae.

RESULTS

Between February, 1996, and December, 1997, we enrolled 174 patients, 168 of whom fulfilled protocol criteria for evaluation. There were 55% males and 63% were <5 years of age. All blood cultures were sterile and there was no correlation between the white blood cell and differential counts and etiology of pneumonia. Etiologic agents were identified in 73 (43%) of 168 patients. Infection was attributed to M. pneumoniae in 7% (12 of 168), C. pneumoniae in 6% (10 of 168), S. pneumoniae in 27% (35 of 129) and viruses in 20% (31 of 157). None of the swab specimens from 75 healthy control children was positive for C. pneumoniae or M. pneumoniae. Clinical response to therapy was similar for the three antibiotic regimens evaluated, including those with infection attributed to bacterial agents.

CONCLUSION

Although a possible microbial etiology was identified in 43% of the evaluable patients, clinical findings and results of blood cultures, chest radiographs and white blood cell and differential counts did not distinguish patients with a defined etiology from those without a known cause for pneumonia. There were no differences in the clinical responses of patients to the antimicrobial regimens studied.

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.

CONCLUSIONS

Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically.

Vascular endothelial growth factor receptor-1 modulates vascular endothelial growth factor-mediated angiogenesis via nitric oxide

The known responses of vascular endothelial growth factor (VEGF) are mediated through VEGF receptor-2 (VEGFR-2/KDR) in endothelial cells. However, it is unknown whether VEGFR-1 (Flt-1) is an inert decoy or a signaling receptor for VEGF during physiological or pathological angiogenesis. Here we report that VEGF-stimulated nitric oxide (NO) release is inhibited by blockade of VEGFR-1 and that VEGFR-1 via NO negatively regulates of VEGFR-2-mediated proliferation and promotes formation of capillary networks in human umbilical vein endothelial cells (HUVECs). Inhibition of VEGFR-1 in a murine Matrigel angiogenesis assay induced large aneurysm-like structures. VEGF-induced capillary growth over 14 days was inhibited by anti-VEGFR-2-blocking antibody as determined by reduced tube length between capillary connections (P < 0.0001) in an in vitro angiogenesis assay. In contrast, loss of VEGFR-1 activity with a neutralizing anti-VEGFR-1 antibody resulted in an increase in the accumulation of endothelial cells (P < 0.0001) and a dramatic decrease in the number of capillary connections that were restored by the addition of NO donor. Porcine aortic endothelial (PAE) cells expressing human VEGFR-1 but not VEGFR-2 plated on growth factor-reduced Matrigel rearranged into tube-like structures that were prevented by anti-VEGFR-1 antibody or a cGMP inhibitor. VEGF stimulated NO release from VEGFR-1- but not VEGFR-2-transfected endothelial cells and placenta growth factor-1 stimulated NO release in HUVECs. Blockade of VEGFR-1 increased VEGF-mediated HUVEC proliferation that was inhibited by NO donors, and potentiated by NO synthase inhibitors. These data indicate that VEGFR-1 is a signaling receptor that promotes endothelial cell differentiation into vascular tubes, in part by limiting VEGFR-2-mediated endothelial cell proliferation via NO, which seems to be a molecular switch for endothelial cell differentiation.

Midgut neuroendocrine tumours with liver metastases: results of the UKINETS study

We intended to identify the prognostic factors and the results of interventions on patients with liver metastatic midgut carcinoids. Five institutions that are part of United Kingdom and Ireland neuroendocrine tumour (NET) group took part in this study. Patients were included if they had histology proven NET of midgut origin and liver metastases at the time of the study. Clinical and biochemical data were collected retrospectively from hospital charts, pathology reports, radiology reports and biochemistry records for each patient. Three hundred and sixty patients were included in the study. The median survival from date of diagnosis was 7.69 years (confidence interval (CI) 6.40-8.99) and 5.95 years (CI 5.02-6.88) from date of diagnosis of liver metastases. On univariate analysis, increasing age at diagnosis, increasing urinary hydroxyindole acetic acid levels, increasing plasma chromogranin A levels, high Ki67, high tumour volume and treatment with chemotherapy were identified as factors associated with a significantly poorer outcome. Resection of liver metastases, resection of small bowel primary, treatment with somatostatin analogue therapy and treatment with peptide receptor therapy were associated with improved prognosis. Multivariate analysis revealed that age at diagnosis (P=0.014), Ki67 level (P=0.039) and resection of primary (P=0.015) were independent predictors of survival. This is the largest study to our knowledge looking specifically at the prognosis and clinical course of patients with liver metastatic midgut NETs. For the first time, we have shown that Ki67 and resection of primary are independent predictors of survival for this group of patients.

Correlation between subjective and objective evaluation of the nasal airway. A systematic review of the highest level of evidence

BACKGROUND

There is no consensus about the value of objective measurements of nasal patency.

OBJECTIVE

To assess the correlation between the subjective sense of nasal patency and the outcomes found with rhinomanometry and acoustic rhinometry.

TYPE OF REVIEW

Structured literature search. SEARCH STRATEGY AND EVALUATION METHOD: Review of English-language articles in which correlations were sought between subjective nasal patency symptoms and objective scores as found with rhinomanometry [nasal airway resistance (NAR)] and acoustic rhinometry [minimal cross-sectional area (MCA)]. Correlations were related to unilateral or combined assessment of nasal passages and to symptomatic nasal obstruction or unobstructed nasal breathing.

RESULTS

Sixteen studies with a level of evidence II-a or II-b fit the inclusion criteria and were further analysed. Almost every possible combination of correlations or lack thereof in relation to the variables included was found. However, when obstructive symptoms were present, a correlation between the patency symptoms with nasal airway resistance and minimal cross-sectional area was found more often than in the absence of symptoms. In cases of bilateral assessment a correlation was found almost as often as it was not between patency symptoms and total nasal airway resistance or combined minimal cross-sectional areas, while in the limited amount of studies in which unilateral assessment was done a correlation was found each time between patency symptoms and nasal airway resistance.

CONCLUSIONS

The correlation between the outcomes found with rhinomanometry and acoustic rhinometry and an individual's subjective sensation of nasal patency remains uncertain. Based on this review, it seems that the chance of a correlation is greater when each nasal passage is assessed individually and when obstructive symptoms are present. There still seems to be only a limited argument for the use of rhinomanometry or acoustic rhinometry in routine rhinologic practice or for quantifying surgical results.

B-lymphocyte heterogeneity: development and characterization of an alloantiserum which distinguishes B-lymphocyte differentiation alloantigens

CBA/N mice and F1 male mice, which are hemizygous for the CBA/N X chromosome, have an immune defect which is associated with the absence (deficiency) of a subpopulation of mature or late developing B lymphocytes. This characteristic was utilized to develop an antiserum that was specific for this subclass of B cells. C57BL/L mice were immunized with DBA/2 spleen calls, and the resulting antisera was absorbed with lymphoid cells derived from immunologically abnormal (CBA/N female X DBA/2 male)F1 male mice. The absorbed antisera was cytotoxic for a subpopulation of lymphocytes that was present in the spleens of adult DBA/2 and (CBA/N female X DBA/2 male)F1 female mice. The cells killed by the absorbed antisera were Ig-bearing, complement receptor-bearing B lymphocytes, which had a low-to-intermediate density of total surface Ig. Moreover, the cells remaining after treatment of adult (CBA/N female X DBA/2 male)F1 female spleen cells with the absorbed antisera and C had a high ratio of surface IgM to IgD. The development of this cytotoxic alloantisera, which is specific for a late developing (mature) subpopulation of B lymphocytes, will allow the functional characterization of subclasses of B lymphocytes.

Vascular endothelial growth factor receptor localization and activation in human trophoblast and choriocarcinoma cells

Vascular endothelial growth factor (VEGF; also known as vascular permeability factor) is a secreted angiogenic growth factor. It is highly specific for endothelial cells, and its receptor, the fms-like tyrosine kinase (flt), has been localized only to endothelial cells in vivo. Here we describe the expression of mRNA encoding flt in human trophoblast as revealed by in situ hybridization. This mRNA is highly expressed in the cytotrophoblast shell and columns and also highly expressed by the extravillous trophoblast (EVT) in the maternal decidua both in the first trimester and at term. The trophoblast-like choriocarcinoma cell line BeWo also expresses this receptor and the related receptor, kinase domain-containing receptor (KDR), which is also a receptor for VEGF. Treatment of the cell line BeWo with VEGF165 stimulated 3H-thymidine incorporation and tyrosine phosphorylation of MAP (mitogen-activated protein) kinase in a time- and dose-dependent fashion. This study is the first demonstration of the presence of flt on non-endothelial cells in vivo and suggests a role for VEGF in the growth and differentiation of cytotrophoblast at implantation.

Alpha 4-integrins mediate antigen-induced late bronchial responses and prolonged airway hyperresponsiveness in sheep

Eosinophils and T lymphocytes are thought to be involved in allergic airway inflammation. Both cells express the alpha 4 beta 1-integrin, very late antigen-4 (VLA-4, CD49d/CD29); alpha 4-integrins can promote cellular adhesion and activation. Therefore, we examined the in vivo effects of a blocking anti-alpha 4 monoclonal antibody, HP 1/2, on antigen-induced early and late bronchial responses, airway hyperresponsiveness, inflammatory cell influx, and peripheral leukocyte counts in allergic sheep. Sheep blood lymphocytes, monocytes, and eosinophils expressed alpha 4 and bound HP 1/2. In control sheep, Ascaris antigen challenge produced early and late increases in specific lung resistance of 380 +/- 42% and 175 +/- 16% over baseline immediately and 7 h after challenge, respectively, as well as airway hyperresponsiveness continuing for 14 d after antigen challenge. Treatment with HP 1/2 (1 mg/kg, i.v.) 30 min before antigen challenge did not affect the early increase in specific lung resistance but inhibited the late-phase increase at 5-8 h by 75% (P < 0.05) and inhibited the post-antigen-induced airway hyperresponsiveness at 1, 2, 7, and 14 d (P < 0.05, for each time). Intravenous HP 1/2 given 2 h after antigen challenge likewise blocked late-phase airway changes and postchallenge airway hyperresponsiveness. Airway administration of HP 1/2 (16-mg dose) was also effective in blocking these antigen-induced changes. Response to HP 1/2 was specific since an isotypic monoclonal antibody, 1E6, was ineffective by intravenous and aerosol administration. Inhibition of leukocyte recruitment did not totally account for the activity of anti-alpha 4 antibody since HP 1/2 neither diminished the eosinopenia or lymphopenia that followed antigen challenge nor consistently altered the composition of leukocytes recovered by bronchoalveolar lavage. Because airway administration of HP 1/2 was also active, HP 1/2 may have inhibited cell activation. Reduction of platelet-activating factor-induced eosinophil peroxidase release from HP 1/2-treated eosinophils supports such a mechanism. These findings indicate a role for alpha 4-integrins in processes that lead to airway late phase responses and persisting airway hyperresponsiveness after antigen challenge.

High prevalence of low plasma thiamine concentration in diabetes linked to a marker of vascular disease

AIMS/HYPOTHESIS

To assess thiamine status by analysis of plasma, erythrocytes and urine in type 1 and type 2 diabetic patients and links to markers of vascular dysfunction.

METHODS

Diabetic patients (26 type 1 and 48 type 2) with and without microalbuminuria and 20 normal healthy control volunteers were recruited. Erythrocyte activity of transketolase, the concentrations of thiamine and related phosphorylated metabolites in plasma, erythrocytes and urine, and markers of metabolic control and vascular dysfunction were determined.

RESULTS

Plasma thiamine concentration was decreased 76% in type 1 diabetic patients and 75% in type 2 diabetic patients: normal volunteers 64.1 (95% CI 58.5-69.7) nmol/l, type 1 diabetes 15.3 (95% CI 11.5-19.1) nmol/l, p < 0.001, and type 2 diabetes 16.3 (95% CI 13.0-9.6) nmol/l, p < 0.001. Renal clearance of thiamine was increased 24-fold in type 1 diabetic patients and 16-fold in type 2 diabetic patients. Plasma thiamine concentration correlated negatively with renal clearance of thiamine (r = -0.531, p < 0.001) and fractional excretion of thiamine (r = -0.616, p < 0.001). Erythrocyte transketolase activity correlated negatively with urinary albumin excretion (r = -0.232, p < 0.05). Thiamine transporter protein contents of erythrocyte membranes of type 1 and type 2 diabetic patients were increased. Plasma thiamine concentration and urinary excretion of thiamine correlated negatively with soluble vascular adhesion molecule-1 (r = -0.246, p < 0.05, and -0.311, p < 0.01, respectively).

CONCLUSIONS/INTERPRETATION

Low plasma thiamine concentration is prevalent in patients with type 1 and type 2 diabetes, associated with increased thiamine clearance. The conventional assessment of thiamine status was masked by increased thiamine transporter content of erythrocytes.

Tryptase inhibitors block allergen-induced airway and inflammatory responses in allergic sheep

Tryptase, a mast cell serine protease, has been implicated in the pathophysiology of allergic asthma, but formal evidence to support this hypothesis has been limited by the lack of specific inhibitors for use in vivo. Therefore, in this study we examined the effects of two inhibitors of tryptase, APC 366 [N-(1-hydroxy-2-naphthoyl)-L-arginyl-L-prolinamide hydrochloride] and BABIM [bis(5-amidino-2-benzimidazolyl)methane] on antigen-induced early and late responses, airway responsiveness as measured by carbachol provocation, microvascular permeability as measured by bronchoalveolar lavage (BAL) albumin concentrations, and tissue eosinophilia from biopsies in allergic sheep. APC 366 and BABIM were administered by aerosol in all experiments. In vehicle control trials, antigen challenge resulted in peak early and late increases in specific lung resistance (SRL) of (mean +/- SE, n = 6) 259 +/- 30% and 183 +/- 27% over baseline, respectively. Treatment with APC 366 (9 mg/3 ml H2O given 0.5 h before, 4 h after, and 24 h after antigen challenge) slightly reduced the peak early response (194 +/- 41%), but significantly inhibited the late response (38 +/- 6%, p < 0.05 versus control trials). Twenty-four hours after challenge, APC 366 also completely blocked the antigen-induced airway hyperresponsiveness to inhaled carbachol observed in the control trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Colocalisation of vascular endothelial growth factor and its Flt-1 receptor in human placenta

Vascular endothelial growth factor (VEGF) is an angiogenic protein which acts on both endothelial and trophoblast cells. In first trimester placenta, VEGF immunoreactive protein was detected in cytotrophoblast shell suggesting a role in the regulation of cytotrophoblast growth and differentiation as they also expressed VEGF receptor (flt-1) protein. VEGF and flt-1 immunoreactive proteins were expressed in Hofbauer cells within the villous mesenchyme, macrophages and in maternal decidual cells while weak VEGF immunoreactive protein was seen in syncytiotrophoblast surrounding the placental villi in first and second trimester placentae. At term, there was relatively weak VEGF and flt-1 immunostaining in the syncytiotrophoblast while intense VEGF immunostaining was seen in the Hofbauer and maternal decidual cells. Extravillous trophoblast showed immunostaining for flt-1 but no staining for VEGF. Both amnion and chorion expressed strong VEGF immunoreactivity throughout gestation. Smooth muscle cells surrounding the vein and arteries of the umbilical cord showed weak VEGF immunoreactivity while no immunoreactivity was localised in endothelial cells. VEGF stimulated parathyroid hormone-related protein (PTHrP) release (mean (+/- SD): basal, 0.96 +/- 0.03; 10 ng/ml VEGF165, 2.07 +/- 0.18 and 20 ng/ml VEGF165, 2.43 +/- 0.18 pmol/l/well of PTHrP1-86) in condition medium from immortalised first trimester trophoblast cell line. These results suggest that VEGF in addition to acting as an autocrine mitogen for trophoblast proliferation may also function as a paracrine mediator of vascular tone by releasing vasorelaxants from trophoblasts.

Release and complex formation of soluble VEGFR-1 from endothelial cells and biological fluids

One of the key molecules promoting angiogenesis is the endothelial cell-specific mitogen, vascular endothelial growth factor (VEGF or VEGF-A), which acts through two high-affinity receptor tyrosine kinases (VEGFR), VEGFR-1 (or Flt-1) and VEGFR-2 (or KDR/Flk-1). It was shown before that a soluble variant of VEGFR-1 (sVEGFR-1) can be generated by differential splicing of the flt-1 mRNA. This soluble receptor is an antagonist to VEGF action, reducing the level of free, active VEGF-A, and therefore, plays a pivotal role in the generation of vascular diseases like pre-eclampsia or intra-uterine growth retardation. Here we show that sVEGFR-1 is produced by cultured human microvascular and macrovascular endothelial cells and a human melanoma cell line. The soluble receptor is mainly complexed with ligands; only 5-10% remains detectable as free, uncomplexed receptor protein. Furthermore, we show the time course of total and free sVEGFR-1 release together with its putative ligands, VEGF-A and placenta growth factor (PIGF), from macrovascular endothelial cells. The release of sVEGFR-1 was quantitatively measured in two different ELISA types. The release of sVEGFR-1 was strongly enhanced by phorbol-ester (PMA); the cells produced up to 22 ng/ml of sVEGFR-1 after 48 hours. The expression of VEGF-A and PIGF was moderately influenced by PMA. We also show a hypoxia-induced increase of sVEGFR-1 expression in cells cultured from placenta, a tissue that has a high flt-1 gene expression. Moreover, we demonstrate that sVEGFR-1 in amniotic fluids acts as a sink for exogenous VEGF165 and PIGF-2. Here, for the first time, to what extent recombinant ligands have to be added to compensate for the sink function of amniotic fluids was analyzed. In conclusion, human endothelial cells produce high levels of sVEGFR-1, which influences the availability of VEGF-A or related ligands. Therefore, sVEGFR-1 may reduce the ligand binding to transmembrane receptors and interfere with their signal transduction.

A case-control study of oesophageal adenocarcinoma in women: a preventable disease

The incidence of adenocarcinoma of the oesophagus in British women is among the highest in the world. To investigate its aetiology, we conducted a multi-centre, population based case-control study in four regions in England and Scotland. We included 74 incident cases in women with histologically confirmed diagnoses of adenocarcinoma of the oesophagus, and 74 female controls matched by age and general practice. High body mass index (BMI) around the age of 20 years (highest vs lowest quartile, adjusted odds ratio (OR) = 6.04, 95% confidence interval (CI) 1.28-28.52) and low consumption of fruit (highest vs lowest quartile, adjusted OR = 0.08, 95% CI 0.01-0.49) were associated with increases in risk. Breastfeeding by women was associated with reduced risk of their subsequently developing this cancer (ever vs never, adjusted OR = 0.41, 95% CI 0.20-0.82) and there was a significant dose-response effect with total duration of breastfeeding. The summary population attributable risk from these three factors was 96% (90% if breastfeeding is excluded). We conclude that high BMI in early adulthood and low consumption of fruit are important risk factors for adenocarcinoma of the oesophagus. Breastfeeding may confer a protective effect but this needs confirmation. This cancer is a largely preventable disease in women.

A study of 20 SLE patients with intravenous immunoglobulin--clinical and serologic response

OBJECTIVE

To test the clinical response of systemic lupus erythematosus (SLE) patients to intravenous immunoglobulins (IVIg), and whether the clinical response of IVIg treatment in SLE is accompanied by modification of SLE-associated autoantibodies/antibodies (Abs) and complement levels.

METHODS

Twenty SLE patients were treated with high-dose (2 g/kg) IVIg monthly, in a 5-d schedule. Each patient received between 1-8 treatment courses. They were evaluated for the clinical response, Systemic Lupus Activity Measure (SLAM) score before and after IVIg, levels of antinuclear antibody (ANA), dsDNA (double-stranded DNA), SS-A or SS-B, ENA (extractable nuclear antigens), C3 and C4 levels before and after the treatment, and before and after each treatment course.

RESULTS

A beneficial clinical response following IVIg treatment was noted in 17 out of 20 patients (85%). Few clinical manifestations responded more to treatment: arthritis, fever, thrombocytopenia, and neuropsychiatric lupus. In 9 patients evaluated before and after IVIg, mean SLAM score decreased from 19. 3+/-4.7 to 4+/-2.9 (P<0.0001). There was a tendency towards abnormal levels of complement and Abs before IVIg courses among the treatment responders compared with the non-responders, and similarly the former tended to have normalization of their abnormal levels more than the latter. These differences were found statistically significant only with respect to C4 and SS-A or SS-B levels before IVIg courses.

CONCLUSION

IVIg has a high response rate among SLE patients. A combination of clinical manifestations, Abs and complement levels may aid in the future in predicting who among SLE patients will benefit more from IVIg treatment.

X-linked B-lymphocyte immune defect in CBA/HN mice. I. Studies of the function and composition of spleen cells

A study of the composition and functional properties of spleen cells from the immune deficient CBA/HN mice and their F1 progeny is reported. While abnormalities were seen in both the numbers and function of thymus-independent (B) lymphocytes, all studies involving thymus-dependent (T) lymphocytes were normal. The X-linked nature of the immune defect in these mice was therefore attributed to abnormal or absent B lymphocytes. The possible nature of this defect and the similarity of the immune defect in these mice to certain human X-linked immunodeficiency diseases are discussed.

Experimental microdissection enables functional harmonisation of pancreatic cancer subtypes

OBJECTIVE

Pancreatic ductal adenocarcinoma (PDA) has among the highest stromal fractions of any cancer and this has complicated attempts at expression-based molecular classification. The goal of this work is to profile purified samples of human PDA epithelium and stroma and examine their respective contributions to gene expression in bulk PDA samples.

DESIGN

We used laser capture microdissection (LCM) and RNA sequencing to profile the expression of 60 matched pairs of human PDA malignant epithelium and stroma samples. We then used these data to train a computational model that allowed us to infer tissue composition and generate virtual compartment-specific expression profiles from bulk gene expression cohorts.

RESULTS

Our analysis found significant variation in the tissue composition of pancreatic tumours from different public cohorts. Computational removal of stromal gene expression resulted in the reclassification of some tumours, reconciling functional differences between different cohorts. Furthermore, we established a novel classification signature from a total of 110 purified human PDA stroma samples, finding two groups that differ in the extracellular matrix-associated and immune-associated processes. Lastly, a systematic evaluation of cross-compartment subtypes spanning four patient cohorts indicated partial dependence between epithelial and stromal molecular subtypes.

CONCLUSION

Our findings add clarity to the nature and number of molecular subtypes in PDA, expand our understanding of global transcriptional programmes in the stroma and harmonise the results of molecular subtyping efforts across independent cohorts.

Localisation of placenta growth factor (PIGF) in human term placenta

Placenta growth factor (PlGF) is a growth factor which belongs to the vascular endothelial growth factor (VEGF) family and is known to bind to the fms-like tyrosine kinase receptor (flt-1). Using Western blot analysis a 50 kDa band was identified in placental protein extract which corresponded to PlGF homodimer. Immunoreactive PlGF was localised to the vasculosyncytial membrane and in the media of large blood vessels of the placental villi, while staining within the mesenchyme was weak and diffuse. There was moderate staining for PlGF in discrete cells in the chorion and no staining in the epithelial layer of the amnion. The maternal decidual cells showed strong staining for PlGF immunoreactive protein. PlGF mRNA was predominantly expressed by the vasculosyncytial membrane of villous trophoblast, whilst there was no apparent expression of PlGF mRNA within the villous mesenchyme. These results suggest that PlGF may be an important paracrine factor for vascular endothelial cells in placental angiogenesis and an autocrine mediator of trophoblast function.

Myths and conspiracy theories on vaccines and COVID-19: Potential effect on global vaccine refusals

The current coronavirus disease 2019 (COVID-19) pandemic is one of the international crises and researchers are working collaboratively to develop a safe and effective COVID-19 vaccine. The World Health Organization recognizes vaccine hesitancy as the world's top threat to public health safety, particularly in low middle-income countries. Vaccine hesitancy can be due to a lack of knowledge, false religious beliefs, or anti-vaccine misinformation. The current situation regarding anti-vaccine beliefs is pointing towards dreadful outcomes. It raises the concern that will people believe and accept the new COVID-19 vaccines despite all anti-vaccine movements and COVID-19-related myths and conspiracy theories. This review discusses the possible detrimental impacts of myths and conspiracy theories related to COVID-19 and vaccine on COVID-19 vaccine refusals as well as other vaccine programs.

Angiopoietin-1 and angiopoietin-2 activate trophoblast Tie-2 to promote growth and migration during placental development

Human placental development involves coordinated angiogenesis and trophoblast outgrowth that are compromised in intrauterine growth restriction (IUGR). As Tie-2((-/-)) mice exhibit growth retardation and vascular network malformation, the expression of Tie-2 and its ligands, angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2), were investigated in human placenta from normal pregnancies and those complicated by severe IUGR. Ribonucleotide protection assays showed no significant change in the expression of Ang-2 mRNA between gestationally matched normal and IUGR placentas; however, immunoblots revealed that Ang-2 protein was significantly decreased in IUGR, suggesting that this may contribute to the abnormal development of the villous vasculature. In situ hybridization studies showed that Ang-1 and Tie-2 were detected in the cyto/syncytiotrophoblast bilayer in first-trimester placenta, whereas Ang-2 mRNA was restricted to the cytotrophoblast, suggesting their role in trophoblast function. At term, Ang-1 mRNA and immunoreactive protein were restricted to the paravascular tissues of the primary stem villi, supporting its role in vessel maturation. In contrast, Ang-2 was expressed throughout the term villous core, perhaps to permit the developing placental vascular network to remain in a state of fluidity. As these studies also revealed that trophoblast, in addition to endothelial cells, expressed Tie-2 receptors, we investigated the potential role of Ang-1/Ang-2 on trophoblast proliferation, migration, and the release of NO. Using spontaneously transformed first-trimester trophoblast cell lines that exhibit cytotrophoblast-like (ED(27)) and extravillous trophoblast-like (ED(77)) properties, we show that the addition of Ang-2 (250 ng/ml) stimulated DNA synthesis in ED(27) trophoblast cells and triggered the release of NO. Ang-1 stimulated trophoblast (ED(77)) migration in a dose-dependent manner that was inhibited by recombinant Tie-2-FC. These data thus imply, for the first time, a specific role for angiopoietins as regulators of trophoblast behavior in the development of the utero/fetoplacental circulation, an action independent of their well-established roles in vascular endothelium.