Intrauterine vertical SARS-CoV-2 infection: a case confirming transplacental transmission followed by divergence of the viral genome

This article includes Author Insights, a video abstract available at https://vimeo.com/bjog/authorinsights16682

The Effect of Progesterone on the Haemostatic Mechanism

The hemostatic effect of progesterone administered vaginally at a dose of 100 mg twice a day throughout one menstrual cycle was investigated and compared with the coagulation factors in one untreated normal menstrual cycle in 15 women. The progesterone treatment resulted in a 20-fold progesterone rise in the early follicular phase from 1.2 nmol/1 in the pretreatment control cycle to levels between 26 and 29 nmol/1 during treatment. Ovulation was completely suppressed in seven women while eight women showed a slight rise in progesterone on treatment days 20 to 25 not compatible with the rise which could have been expected if ovulation had occurred. The effects found on haemostasis during progesterone treatment varied with the menstrual cycle and were so small that they could as well be due to chance and not to treatment.

Characterization of a novel brain barrier ex vivo insect-based P-glycoprotein screening model

In earlier studies insects were proposed as suitable models for vertebrate blood–brain barrier (BBB) permeability prediction and useful in early drug discovery. Here we provide transcriptome and functional data demonstrating the presence of a P-glycoprotein (Pgp) efflux transporter in the brain barrier of the desert locust (Schistocerca gregaria). In an in vivo study on the locust, we found an increased uptake of the two well-known Pgp substrates, rhodamine 123 and loperamide after co-administration with the Pgp inhibitors cyclosporine A or verapamil. Furthermore, ex vivo studies on isolated locust brains demonstrated differences in permeation of high and low permeability compounds. The vertebrate Pgp inhibitor verapamil did not affect the uptake of passively diffusing compounds but significantly increased the brain uptake of Pgp substrates in the ex vivo model. In addition, studies at 2°C and 30°C showed differences in brain uptake between Pgp-effluxed and passively diffusing compounds. The transcriptome data show a high degree of sequence identity of the locust Pgp transporter protein sequences to the human Pgp sequence (37%), as well as the presence of conserved domains. As in vertebrates, the locust brain–barrier function is morphologically confined to one specific cell layer and by using a whole-brain ex vivo drug exposure technique our locust model may retain the major cues that maintain and modulate the physiological function of the brain barrier. We show that the locust model has the potential to act as a robust and convenient model for assessing BBB permeability in early drug discovery.

The grasshopper: a novel model for assessing vertebrate brain uptake

The aim of the present study was to develop a blood-brain barrier (BBB) permeability model that is applicable in the drug discovery phase. The BBB ensures proper neural function, but it restricts many drugs from entering the brain, and this complicates the development of new drugs against central nervous system diseases. Many in vitro models have been developed to predict BBB permeability, but the permeability characteristics of the human BBB are notoriously complex and hard to predict. Consequently, one single suitable BBB permeability screening model, which is generally applicable in the early drug discovery phase, does not yet exist. A new refined ex vivo insect-based BBB screening model that uses an intact, viable whole brain under controlled in vitro-like exposure conditions is presented. This model uses intact brains from desert locusts, which are placed in a well containing the compound solubilized in an insect buffer. After a limited time, the brain is removed and the compound concentration in the brain is measured by conventional liquid chromatography-mass spectrometry. The data presented here include 25 known drugs, and the data show that the ex vivo insect model can be used to measure the brain uptake over the hemolymph-brain barrier of drugs and that the brain uptake shows linear correlation with in situ perfusion data obtained in vertebrates. Moreover, this study shows that the insect ex vivo model is able to identify P-glycoprotein (Pgp) substrates, and the model allows differentiation between low-permeability compounds and compounds that are Pgp substrates.

The Interconnection between Sympathetics, Microcirculation, and Insulin Resistance in Hypertension

The pathophysiology of the frequent association of insulin resistance and hypertension has not been elucidated. The skeletal muscle is the major site of insulin resistance; when stimulated with insulin, the hypertensive skeletal muscles extract less glucose than the normotensive. We postulate that hypertension-related changes in the skeletal muscle microcirculation contribute to the impaired glucose uptake in hypertension. Vascular rarefaction in hypertension impairs the delivery of insulin and glucose to muscle cells. Insulin resistance has been described both in human and experimental hypertension and both conditions are associated with vascular rarefaction. Functional studies (response to whole body or forearm exercise) and anatomic investigations (conjunctival photography, mesenteric and muscle biopsies) show vascular rarefaction in human hypertension. In addition, patients with hypertension are known to have a larger proportion of insulin resistant, poorly vascularized fast twitch muscle fibers. A few interventions can increase or decrease insulin resistance and these effects can be explained on hemodynamic grounds. Beta adrenergic blocking agents aggravate insulin resistance, and their main hemodynamic effect is a decrease of cardiac output. Converting enzyme inhibitors, alpha adrenergic blocking agents and possibly calcium antagonists decrease the insulin resistance, and their major hemodynamic effect is vasodilation. Physical training decreases insulin resistance; a higher capillary density in skeletal muscles is the hallmark of physical training. A hypothesis ought to rest on sufficient supporting data and its validity ought to lend itself to experimental verification. We believe our hypothesis meets both criteria. After outlining the supporting evidence we propose a number of tests to prove or disprove the hypothesis. In addition to the testable hypothesis we also speculate on the possible cause of the frequent association between hypertension and insulin resistance. We propose that both insulin resistance and blood pressure elevation represent a facet of the "defense reaction" which might have offered an early survival advantage and may, over evolutionary times, have fostered natural selection of subjects with both conditions.

Body composition and glucose metabolism in hypertensive middle-aged males

Body fat, body cell mass, fasting blood sugar, glucose tolerance and fasting insulin have been determined in 106 hypertensive males aged 47-54years and in 41 normotensive 50-year-old males. Both groups were derived from screening examinations in random population samples. The hypertensive subjects were more often obese and had more often an impaired glucose tolerance and a higher fasting insulin compared with the normotensive subjects. The metabolic differences were not explained simply by the higher degree of obesity in the hypertensive subjects, as the differences remained when the hypertensive subjects were matched for body fat with normotensive controls. The impaired glucose metabolism demonstrated quantitatively in an unselected group of hypertensive subjects, might be one of the factors explaining the variable prognosis in hypertensive subjects.

Low-dose antihypertensive treatment with a thiazide diuretic is not diabetogenic. A 10-year controlled trial with bendroflumethiazide

Blood pressure (BP) and metabolic variables were determined initially and after 1, 2, 4, 6 and 10 years' treatment in two groups of hypertensive men (n = 53 each) randomized to bendroflumethiazide 2.5-5 mg/day or propranolol 160-320 mg daily. There was no significant differences in BP or metabolic variables between the two groups at entry. BP was reduced to the same degree by both treatments. Five men in the propranolol group and one man in the thiazide group developed clinically overt diabetes during follow-up. Fasting blood sugar increased slightly but significantly though equally in both groups. Oral glucose tolerance was initially impaired to the same degree in both groups but improved significantly during treatment with both drugs. Fasting insulin increased slightly but to the same degree. While serum potassium decreased significantly in the thiazide group, the total body potassium was unchanged in this group. In the propranolol group, serum potassium rose, while total body potassium decreased significantly. Serum urate increased in both groups, though slightly more during thiazide treatment. One case of gout was found in each group. There was no difference in serum lipids between the two groups. The finding in this long-term trial indicate that in middle-aged men with mild to moderate hypertension a low-dose thiazide diuretic like bendroflumethiazide is as effective and safe an antihypertensive agent as the beta-blocker propranolol is and that it does not induce diabetes. The total clinical picture favors the retention of thiazide diuretics as a first choice drug in hypertension.

Antihypertensive effect and side-effects of bendroflumethiazide and propranolol

The antihypertensive effect and side-effects during 12 months' treatment with bendroflumethiazide and propranolol have been compared in two randomly selected, equally large groups (n= 53) of previously untreated male hypertensives. Systolic BP above 170 or diastolic BP above 105 mmHg on two occasions were defined as hypertension. The same BP reduction was achieved in both groups. During the 12 months' treatment one subject on bendroflumethiazide developed diabetes mellitus and one on propranolol developed cardiac decompensation. None developed gout. Contrary to what had been presumed, glucose tolerance improved during 12 months' treatment with both agents, while there were no changes in fasting blood sugar, insulin or triglyceride concentrations. No changes were found in serum potassium or total body potassium during 12 months' bendroflumethiazide treatment, while serum potassium increased during treatment with propranolol. Uric acid increased slightly during treatment with both agents. Prolongation of the follow-up to 24 months did not change any of the findings regarding metabolic changes during treatment. The frequency of subjective side-effects decreased to the same extent during treatment with both drugs. It is concluded that bendroflumethiazide and propranolol are equally useful as antihypertensive agents and that the risk of impariment of glucose metabolism and potassium balance seems to be very slight during treatment with bendroflumethiazide in mild hypertension.

The use of diuretics in modern antihypertensive therapy

A review is made to sum up the indications when diuretics may be the drug of choice in the treatment of hypertension. Advantages from the combined treatment of thiazide diuretics and other antihypertensive agents are also emphasized. Adverse effects from diuretic treatment, i.e. hypokalemia, hyperuricemia, impaired glucose tolerance and risks associated with unfavourable serum lipoprotein patterns are discussed. It is concluded that from a hemodynamic point of view thiazide diuretics can be a good therapeutic alternative for most patients, excepting those with hyperkinetic circulation. It is recommended to use lower doses of thiazide diuretics than previously and the monitoring of S-potassium is necessary in all patients.

Nucleotide sequence, genomic organization, and chromosomal localization of genes encoding the human NMDA receptor subunits NR3A and NR3B

The N-methyl-D-aspartate (NMDA) receptors are glutamate-regulated ion channels that are critically involved in important physiological and pathological functions of the mammalian central nervous system. We have identified and characterized the gene encoding the human NMDA receptor subunit NR3A (GRIN3A), as well as the gene (GRIN3B) encoding an entirely novel subunit that we named NR3B, as it is most closely related to NR3A (57.4% identity). GRIN3A localizes to chromosome 9q34, in the region 13-34, and consists of nine coding exons. The deduced protein contains 1115 amino acids and shows 92.7% identity to rat NR3A. GRIN3B localizes to chromosome 19p13.3 and contains, as does the mouse NR3B gene (Grin3b), eight coding exons. The deduced proteins of human and mouse NR3B contain 901 and 900 amino acid residues, respectively (81.6% identity). In situ hybridization shows a widespread distribution of Grin3b mRNA in the brain of the adult rat.

The orphan receptor ALK7 and the Activin receptor ALK4 mediate signaling by Nodal proteins during vertebrate development

Nodal proteins have crucial roles in mesendoderm formation and left-right patterning during vertebrate development. The molecular mechanisms of signal transduction by Nodal and related ligands, however, are not fully understood. In this paper, we present biochemical and functional evidence that the orphan type I serine/threonine kinase receptor ALK7 acts as a receptor for mouse Nodal and Xenopus Nodal-related 1 (Xnr1). Receptor reconstitution experiments indicate that ALK7 collaborates with ActRIIB to confer responsiveness to Xnr1 and Nodal. Both receptors can independently bind Xnr1. In addition, Cripto, an extracellular protein genetically implicated in Nodal signaling, can independently interact with both Xnr1 and ALK7, and its expression greatly enhances the ability of ALK7 and ActRIIB to respond to Nodal ligands. The Activin receptor ALK4 is also able to mediate Nodal signaling but only in the presence of Cripto, with which it can also interact directly. A constitutively activated form of ALK7 mimics the mesendoderm-inducing activity of Xnr1 in Xenopus embryos, whereas a dominant-negative ALK7 specifically blocks the activities of Nodal and Xnr1 but has little effect on other related ligands. In contrast, a dominant-negative ALK4 blocks all mesoderm-inducing ligands tested, including Nodal, Xnr1, Xnr2, Xnr4, and Activin. In agreement with a role in Nodal signaling, ALK7 mRNA is localized to the ectodermal and organizer regions of Xenopus gastrula embryos and is expressed during early stages of mouse embryonic development. Therefore, our results indicate that both ALK4 and ALK7 can mediate signal transduction by Nodal proteins, although ALK7 appears to be a receptor more specifically dedicated to Nodal signaling.

Experimental follow-up model for clinical frontal sinus obliteration with bioactive glass (S53P4)

Bioactive glass S53P4 (BG) is an osteoconductive allograft material. Since 1990, BG has been used in the obliteration of frontal sinuses in more than 30 consecutive patients. The patients have been monitored regularly with clinical examinations, computer tomography (CT) scans, laboratory tests and, in a few cases, biopsies have also been obtained. The material has been well tolerated and no loss of volume of obliteration material has been seen in the obliterated sinuses. However, in repeated CT monitoring and with Region of Interest (ROI) analysis, a decrease in the density of the obliteration material inside the frontal sinuses has been seen. In the present study, the clinical conditions after an obliteration operation were simulated and the behaviour of the BG in the obliterated area was observed. The aim was to study whether it is possible indirectly to estimate the resorption of a massive amount of BG with ROI analysis for monitoring the clinical success of the treatment. Thus two sizes of granules (0.63-0.8 mm and 0.8-1.0 mm) in eight separate BG amounts, weight 25 g, were tested in simulated body fluid (SBF) in standard conditions. The dissolution of silicon (Si) and phosphate (P) was detected with direct plasma atom emission spectroscopy (DCP-AES) monthly up to 6 months. The BG amounts were scanned with CT and the slices analysed using the ROI technique at 1, 3 and 6 months. The cumulative loss of Si and P in SBF was significant during the study (p < 0.0001) and it was stronger with smaller than with larger granules (p < 0.0001). This was shown correspondingly by the decrease of Hounsfield units (p < 0.0001) in ROI analysis. The method seems reliably to reveal the resorption of BG for clinical purposes.

Identification and characterization of a Drosophila nuclear proteasome regulator. A homolog of human 11 S REGgamma (PA28gamma )

We report the cloning and characterization of a Drosophila proteasome 11 S REGgamma (PA28) homolog. The 28-kDa protein shows 47% identity to the human REGgamma and strongly enhances the trypsin-like activities of both Drosophila and mammalian 20 S proteasomes. Surprisingly, the Drosophila REG was found to inhibit the proteasome's chymotrypsin-like activity against the fluorogenic peptide succinyl-LLVY-7-amino-4-methylcoumarin. Immunocytological analysis reveals that the Drosophila REG is localized to the nucleus but is distributed throughout the cell when nuclear envelope breakdown occurs during mitosis. Through site-directed mutagenesis studies, we have identified a functional nuclear localization signal present in the homolog-specific insert region. The Drosophila PA28 NLS is similar to the oncogene c-Myc nuclear localization motif. Comparison between uninduced and innate immune induced Drosophila cells suggests that the REGgamma proteasome activator has a role independent of the invertebrate immune system. Our results support the idea that gamma class proteasome activators have an ancient conserved function within metazoans and were present prior to the emergence of the alpha and beta REG classes.

Enhanced left ventricular endocardial border delineation with an intravenous injection of SonoVue, a new echocardiographic contrast agent: A European multicenter study

The safety and efficacy of SonoVue (also referred to as BR1), a new contrast agent for delineating endocardial border of the left ventricle after intravenous administration, was assessed. Two hundred and eighteen patients with suspected coronary artery disease undergoing fundamental echocardiography for the assessment of left ventricle were enrolled in a prospective multicenter, single blind, cross-over study with random sequence allocation of four different doses of SonoVue. Endocardial border definition in the apical and parasternal views was scored as 0 = not visible, 1 = barely visible, and 2 = well visualized before and after contrast enhancement. Analysis was performed by two pairs of off-site observers. Safety of SonoVue was also assessed. Results of our study indicated that the mean improvements in the endocardial border visualization score were as follows: 3.1 +/- 7.8 (95% CI, 2.5 and 3.7) for 0.5 ml, 3.4 +/- 8.0 (95% CI, 2.8 and 4.0) for 1 ml, 3.4 +/- 7.9 (95% CI, 2.8 and 4.0) for 2 ml, and 3.7 +/- 8.0 (95% CI, 3.1 and 4.3) for 4 ml (P < 0.05 for all doses from baseline). Changes from baseline in endocardial visualization scores were also seen in the apical views (P < 0.05) and they were dose-dependent (P < 0.001). Similar enhancements of endocardial visualization scores were observed in the apical views in patients with suboptimal baseline echocardiographic images. Diagnostic confidence for assigning a score and image quality also were significantly better following contrast enhancement. No significant changes in the laboratory parameters and vital signs were noted following contrast enhancement, and the side effects were minimal. It was concluded that SonoVue is safe and effective in delineating endocardial border, including in patients with suboptimal baseline images.

Clara cell secretory protein. Levels in BAL fluid after smoking cessation

STUDY OBJECTIVES

The bronchiolar Clara cell is a major target for tobacco smoke exposure. To improve our understanding of the putative regenerative/repair mechanism(s) in the bronchiolar epithelium, we measured the levels of the Clara cell secretory protein (CCSP) in BAL fluid in healthy volunteers following smoking cessation.

DESIGN

BAL was performed before smoking cessation, and at 1, 3, 6, 9, and 15 months following smoking cessation, in eight healthy volunteers with a previous mean cigarette consumption of 19 pack-years. The levels of CCSP in BAL fluid were assessed in immunoblotting experiments using an antibody against human CCSP.

RESULTS

Significantly (p < 0.05) higher levels of CCSP in BAL fluid were observed at 3, 6, and 9 months after smoking cessation, while the levels of CCSP in BAL fluid at 15 months after smoking cessation were the same as those before smoking cessation.

CONCLUSIONS

Despite the long history of smoking among patients in the present study group, signs of early regeneration in the bronchiolar epithelium were noted, in that the levels of CCSP in BAL fluid were elevated at the indicated time points following smoking cessation. Furthermore, we propose that the insult to the bronchiolar epithelium made by cigarette smoking caused the levels of CCSP in the BAL fluid at 15 months after smoking cessation to return to the levels noted before smoking cessation. The present study suggests a role for CCSP as a marker for nonciliated bronchiolar cell function.

Decreased pulmonary levels of the anti-inflammatory Clara cell 16 kDa protein after induction of airway inflammation in asthmatics

The Clara cell 16 kDa protein (CC16) maps to an atopy-associated region of chromosome 11 and has been ascribed an anti-inflammatory function. Using reverse-phase HPLC and Western blot analysis, we have evaluated the polypeptide pattern in bronchoalveolar lavage (BAL) fluid retrieved from asthmatics, before and after induction of airway inflammation by low-dose allergen inhalation challenge. A prominent decrease of CC16 was seen after induction of inflammation, and a further CC16 decrease was observed in lavage fluid where surfactant had been removed. Reduced levels of pulmonary CC16 may cause loss of anti-inflammatory activity in the airways and contribute to the development of airway inflammation in asthma.

C/EBPalpha and C/EBPdelta activate the clara cell secretory protein gene through interaction with two adjacent C/EBP-binding sites

The Clara cell secretory protein (CCSP) gene is a cell-specific differentiation marker for the bronchiolar Clara cell. Previous studies suggest that CCAAT/enhancer binding protein (C/EBP)alpha is involved in controlling differentiation-dependent gene expression in the distal lung. In this study, immunofluorescence studies demonstrated high level expression of C/EBPdelta in the bronchiolar epithelium as well as lower levels of C/EBPalpha. Cotransfection studies in the lung epithelial cell line A549 showed that both C/EBPalpha and C/EBPdelta activate the murine CCSP gene and that a C/EBP-response element resides in the proximal CCSP promoter. C/EBPdelta exhibits an approximately 2-fold higher transactivation potential than does C/EBPalpha. DNase I footprint analyses revealed a footprint region located at -100 to -62 bp, corresponding to two C/EBP-binding sites. Mutation of either site resulted in abolished or strikingly reduced transactivation of the CCSP promoter by C/EBPalpha and C/EBPdelta, as well as impaired binding of both factors, indicating that the two C/EBP-binding sites form a compound response element. In electrophoretic mobility shift assays, it was shown that C/EBPalpha and C/EBPdelta can bind to both C/EBP sites, whereas in DNase I footprint analyses, the interaction of C/EBPalpha with the proximal site was weak. Furthermore, electrophoretic mobility shift assays demonstrated that C/EBPalpha and C/EBPdelta preferentially form heterodimers at both binding sites. Cotransfections with C/EBPalpha and C/EBPdelta together resulted in a superinduction of the CCSP promoter, indicating a regulatory role for the C/EBPalpha-C/EBPdelta heterodimers. Our findings demonstrate that C/EBPalpha and C/EBPdelta regulate the CCSP gene through a compound response element and suggest that these factors are important for the differentiation-dependent expression of CCSP.

Elimination of cholesterol as cholestenoic acid in human lung by sterol 27-hydroxylase: evidence that most of this steroid in the circulation is of pulmonary origin

Human alveolar macrophages have exceptionally high capacity to convert cholesterol into 27-hydroxycholesterol and cholestenoic acid by the sterol 27-hydroxylase mechanism. It is shown here that the human lung has a higher content of 27-hydroxycholesterol relative to cholesterol than any other organ. In order to evaluate the importance of the sterol 27-hydroxylase mechanism for cholesterol homeostasis in the lung, the production of cholestenoic acid by human lung was investigated. Removal of one lung reduced the level of cholestenoic acid in the circulation by 48 +/- 4% (P < 0.005). The levels of cholestenoic acid in the pulmonary artery and in the pulmonary vein showed significant differences (P < 0.002) with higher levels in the pulmonary vein (108 +/- 16 and 104 +/- 16 ng/mL, respectively). This corresponds to a net flux of cholestenoic acid from the lung of about 14 mg/day, which is more than 80% of the reported removal of this oxysterol and its metabolites from the circulation by the liver per day. Bypassing the lung for 60 min led to a reduction in circulating cholestenoic acid (30%) that fits with a pulmonary origin when taking into account the half-life of cholestenoic acid. The level of circulating cholestenoic acid was found to be less in patients with different lung diseases. It is evident that most of the cholestenoic acid in the circulation is of pulmonary origin. The present results suggest that the sterol 27-hydroxylase in the lung is responsible for at least half of the total flux of 27-oxygenated cholesterol metabolites to the liver and that this enzyme system may be of importance for cholesterol homeostasis in the lung.

In vivo modulation of glucocorticoid receptor mRNA by inhaled fluticasone propionate in bronchial mucosa and blood lymphocytes in subjects with mild asthma

BACKGROUND

In vivo regulation of the glucocorticoid receptor (GR) by glucocorticoids provides a means of modulating sensitivity of targeted cells.

OBJECTIVE

We sought to determine the in vivo modulation of GR mRNA expression by fluticasone propionate (FP) in subjects with mild asthma.

METHODS

Ten atopic asthmatic subjects were treated with FP 250 microg twice daily for 4 weeks. Before and after treatment, the patients underwent fiberoptic bronchoscopy with endobronchial biopsy and sampling of venous blood for measurements of GR mRNA levels. A solution hybridization assay was used for quantitative analysis of GR mRNA. In addition, a 24-hour urinary cortisol excretion and an adrenocorticotropic hormone test before and after treatment with FP were performed.

RESULTS

A high interindividual variation in GR mRNA expression was seen. However, we detected a significant reduction of the GR mRNA levels in the endobronchial biopsy specimens after FP treatment (36.6 +/- 23.1 and 25.0 +/- 10.9 amol GR mRNA/microg RNA, respectively; P <.01). In the peripheral blood lymphocytes an even more striking downregulation of the GR by its cognate ligand was documented (30.3 +/- 26.5 and 8.8 +/- 5 amol GR mRNA/microg RNA, respectively; P <.001), possibly reflecting differences in glucocorticoid sensitivity between tissues. A small but significant reduction of the 24-hour urinary cortisol excretion was observed (233 +/- 109 and 157 +/- 66 nmol/L, respectively; P <.01), whereas the feedback regulation of glucocorticoid synthesis by means of the hypothalamic-pituitary-adrenal axis as assessed by the adrenocorticotropic hormone test remained normal after treatment with FP.

CONCLUSION

The results in this study confirm the potency of the inhaled corticosteroid FP and provide evidence for a considerable tissue-specific interindividual variation in the expression of the GR.

[Is antihypertensive treatment a risk factor of coronary disease? Therapy-related triglyceride increase nor diabetes increase the risk]

In an observational study designed to determine whether metabolic changes during long-term antihypertensive drug treatment are associated with an increased risk of coronary heart disease (CHD), 686 middle-aged hypertensive men recruited from a random population screening sample were followed up for 15 years. Antihypertensive treatment predominantly consisted of beta-adrenoceptor blockers and/or thiazide diuretics. CHD and diabetes mellitus were checked for at annual examinations. Time-dependent Cox regression analysis was used to determine correlation between the incidence of CHD and entry characteristics, the monitored serum levels of cholesterol and triglyceride concentrations and the development of diabetes mellitus. Univariate analysis showed the presence of diabetes mellitus a entry to the study and increased baseline serum concentrations of cholesterol and of triglycerides each to be a significant predictor of CHD, the respective relative risks (RR) being 2.12, 1.21 and 1.21. However, analysis of monitored levels of metabolic variables during follow-up showed only an increased serum cholesterol concentration to be significantly and independently associated with CHD (RR 1.07). Although serum triglyceride concentrations increased slightly during follow-up, they were unrelated to the incidence of CHD; nor was onset of diabetes mellitus during follow-up significantly associated with an increased risk of CHD (RR 1.48. Thus, the study showed the presence of metabolic disturbances such as diabetes mellitus and hyperlipidaemia before the start of antihypertensive treatment to be of positive predictive value in middle-aged hypertensive men, and an increase in the monitored serum cholesterol level to be an independent predictor of CHD, whereas neither drug-related diabetes nor an increase in the monitored serum triglyceride concentration seemed to be associated with the occurrence of CHD.

Zona pellucida thickness variation and occurrence of visible mononucleated blastomers in preembryos are associated with a high pregnancy rate in IVF treatment

PURPOSE

The ability of six morphological criteria (embryo development rate, fragmentation, regularity of blastomere shape, equality of blastomere size, zona pellucida thickness variation [ZPTV], and visible mononucleated blastomeres [VMBs]) to predict pregnancy in IVF treatment cycles was evaluated.

METHODS

In order to select a homogeneous study group, 85 consecutive nulliparous couples with single tubal infertility undergoing their first IVF treatment and receiving three preembryos at embryo replacement 2 days after ovum pickup were included.

RESULTS

A total of 255 preembryos was replaced two days after ovum pickup and resulted in 34 clinical pregnancies (40%). By logistic regression analysis, ZPTV and VMBs showed highly significant and strong predictive values, whereas none of the other parameters was a significant predictor of pregnancy. In the treatments in which all replaced preembryos had a ZPTV of less than 15%, the pregnancy rate was extremely low (1/22). If the maximum ZPTV of any of the replaced preembryos was in the interval between 15 and 20%, the pregnancy rate was 24.1% (7129). In the treatments in which at least one preembryo had a ZPTV of more than 20%, the pregnancy rate was 76.5% (26/34). When VMBs were added to the results of the ZPTV analysis, the pregnancy rate was as high as 92.3% (24/26).

CONCLUSIONS

ZPTV and VMBs seem to be strong predictors of pregnancy in IVF treatment and thus important indicators of good embryo quality.

Elimination of cholesterol in macrophages and endothelial cells by the sterol 27-hydroxylase mechanism. Comparison with high density lipoprotein-mediated reverse cholesterol transport

Cultured macrophages and endothelial cells have been reported to secrete 27-oxygenated metabolites of cholesterol. This mechanism was compared with the classical high density lipoprotein (HDL)-dependent reverse cholesterol transport. Under standard conditions, macrophage preparations had considerably higher capacity to secrete 27-hydroxycholesterol and 3beta-hydroxy-5-cholestenoic acid than had endothelial cells and fibroblasts. Western blotting showed that lung macrophages contained the most sterol 27-hydroxylase protein of the cells tested. The relative amounts of 3beta-hydroxy-5-cholestenoic acid produced by the macrophages were also highest. Macrophages derived from monocytes of patients with sterol 27-hydroxylase deficiency did not secrete 27-oxygenated products, demonstrating that sterol 27-hydroxylase is the critical enzyme for the conversion of cholesterol into the 27-oxygenated steroids. That sterol 27-hydroxylase is responsible not only for 27-hydroxylation of cholesterol but also for the further oxidation of this steroid into 3beta-hydroxy-5-cholestenoic acid was shown with use of tritium-labeled 27-hydroxycholesterol and an inhibitor of sterol 27-hydroxylase. Secretion of 27-oxygenated products by the cultured macrophages as well as the ratio between the alcohol and the acid appeared to be dependent upon total 27-hydroxylase activity, the availability of substrate cholesterol, and the presence of an acceptor for 27-hydroxycholesterol in the medium. With albumin as extracellular acceptor, the major secreted product was 3beta-hydroxy-5-cholestenoic acid. Under such conditions, secretion of labeled 27-oxygenated products was higher than that of labeled cholesterol from lung alveolar macrophages preloaded with [4-14C]cholesterol. With HDL as acceptor, 27-hydroxycholesterol was the major secreted product, and the total secretion of labeled 27-oxygenated products was only about 10% of that of labeled cholesterol. Thus, 27-hydroxycholesterol and cholesterol may compete for HDL-mediated efflux from the cells. The results support the contention that the sterol 27-hydroxylase-mediated elimination of cholesterol is more important in macrophages than in endothelial cells. This mechanism may be an alternative and/or a complement to the classical HDL-mediated reverse cholesterol transport in macrophages, in particular when the concentration of HDL is low.

Prediction of changes in levels of haemostatic variables during natural menstrual cycle and ovarian hyperstimulation

To find if there is a relation between levels of haemostatic variables at low and high hormonal levels (oestradiol and progesterone) in an individual, blood samples were drawn from 12 women repeatedly during one menstrual cycle (Study I) and from 14 women undergoing in vitro fertilization, before hormonal stimulation and daily during the periovulatory period (Study II). Regression coefficients were calculated between minimum (independent) and maximum (dependent) values in both studies. In Study II highly significant regression coefficients were found between oestradiol minimum (pretreatment) and maximum (median 105 and 4730 pmol/l, respectively) for coagulation factors FVIII, von Willebrand Factor (antigen), FVII (activity and antigen), fibrinogen, protein C, protein S (free), antithrombin, plasminogen and plasminogen activator inhibitor-1; furthermore, between progesterone-minimum at day -3 or -2 (related to ovum pick up) and maximum (median 4.7 and 98 nmol/l, respectively) for FVIII, von Willebrand Factor, FVII (activity and antigen), protein C, protein S (free), and plasminogen. In Study I, where much lower hormonal levels were obtained at maximum (oestradiol median 297 pmol/l and progesterone 47 nmol/l), the same pattern was observed especially for FVII, FX, fibrinogen, plasminogen and plasmin inhibitor. Thus, the concentration of a haemostatic variable at a low oestradiol or progesterone level can predict the level at a high hormonal level.

The effect of progesterone on the haemostatic mechanism

The hemostatic effect of progesterone administered vaginally at a dose of 100 mg twice a day throughout one menstrual cycle was investigated and compared with the coagulation factors in one untreated normal menstrual cycle in 15 women. The progesterone treatment resulted in a 20-fold progesterone rise in the early follicular phase from 1.2 nmol/l in the pretreatment control cycle to levels between 26 and 29 nmol/l during treatment. Ovulation was completely suppressed in seven women while eight women showed a slight rise in progesterone on treatment days 20 to 25 not compatible with the rise which could have been expected if ovulation had occurred. The effects found on haemostasis during progesterone treatment varied with the menstrual cycle and were so small that they could as well be due to chance and not to treatment.

On the value of menorrhagia as a predictor for coagulation disorders

The value of menorrhagia as a predictor for mild bleeding disorders has been very little studied and the results are divergent. In the present study on 30 women with objectively verified menorrhagia, we found a significantly increased prevalence of von Willebrand's disease (20%). By keeping a strict sampling and laboratory routine, and by restricting sampling to cycle days 5-7, we also obtained a very low interindividual variation of von Willebrand factor and coagulation factor VIII. We conclude that menorrhagia is a valuable predictor for coagulation and platelet disorders, and that time of sampling is of importance. This should be considered in the investigation of menorrhagia, and can be a guideline in looking for mild bleeding disorders.

The degree of natural allergen exposure modifies eosinophil activity markers in the circulation of patients with mild asthma

We have previously found that CD9, CD11b, and intracellular ECP (EG2) may be used as activity markers for eosinophils in vitro. The main object of the present study was to determine whether these markers can reflect eosinophil activation in vivo in relation to allergen exposure. for this purpose, six patients with a history of allergic rhinitis and occasional asthma symptoms during the pollen season participated. Blood donors served as controls. Peripheral blood eosinophils were analyzed according to the FOG method and flow cytometry, before and during one birch pollen season with high pollen load (HPL) and one with low pollen load (LPL). The CD9 expression on peripheral eosinophils from the patients was significantly increased both before (P < 0.05) and during (P < 0.01) HPL season, and CD11b expression solely during HPL season (P = 0.01) as compared to controls. The intracellular expression of the EG2 epitope was increased before (P < 0.01) and during (P < 0.05) HPL season, and increased significantly (P < 0.05) during season as compared to before. No changes were observed before and during LPL season. The proportion of eosinophils was increased both before (P < 0.05) and during (P < 0.001) the HPL season as compared to controls. The markers CD9, EG2, and, to a lesser extent, CD11b seem to detect activated eosinophils in the circulation, whereas EG2 may also reflect increased antigen exposure during season.

Diabetes mellitus and raised serum triglyceride concentration in treated hypertension--are they of prognostic importance? Observational study

OBJECTIVE

To analyse whether metabolic changes during long term treatment with antihypertensive drugs are associated with an increased risk of coronary heart disease.

DESIGN

Observational study.

SETTING

Gothenburg, Sweden.

SUBJECTS

686 middle aged hypertensive men, recruited after screening of a random population sample, and followed for 15 years during treatment with predominantly beta adrenoceptor blockers or thiazide diuretics, or both. Coronary heart disease and diabetes mellitus were registered at yearly patient examinations. Entry characteristics, as well as within study serum concentrations of cholesterol and triglycerides and the development of diabetes mellitus, were related to the incidence of coronary heart disease in a time dependent Cox's regression analysis.

MAIN OUTCOME VARIABLE

Coronary heart disease morbidity.

RESULTS

Diabetes mellitus, raised serum cholesterol and triglyceride concentrations present at the beginning of the study were all significantly predictive of coronary heart disease in univariate analysis. The relative risk of diabetes mellitus and of a 1 mmol/l increase in the cholesterol and triglyceride concentrations was 2.12 (95% confidence interval 1.11 to 4.07), 1.21 (1.05 to 1.39), and 1.21 (1.03 to 1.43) respectively. However, when the within study metabolic variables were analysed, only the serum cholesterol concentration was significantly and independently associated with coronary heart disease (relative risk 1.07 (1.02 to 1.13)). Although the triglyceride concentrations increased slightly during the follow up, the within study serum triglyceride concentrations were not associated with the incidence of coronary heart disease (1.04 (0.96 to 1.10)). New diabetes mellitus-that is, onset during follow up-was not significantly associated with an increased risk for coronary heart disease (1.48 (0.37 to 6.00)).

CONCLUSIONS

Metabolic disturbances such as diabetes mellitus and hyperlipidaemia presenting before the start of antihypertensive treatment have a prognostic impact in middle aged, treated hypertensive men. Moreover, while within study cholesterol concentration was an independent predictor of coronary heart disease, drug related diabetes mellitus and raised serum triglyceride concentrations that are associated with treatment do not seem to have any major impact on the coronary heart disease prognosis in this category of patients.

Survey of consumption fish from Swedish waters for chlorinated pesticides and polychlorinated biphenyls

In this survey eighty-seven samples of consumption fish comprising mainly of salmon, pike, eel, herring, whitefish, sea-trout, perch, pike-perch, mackerel, cod, flounder, plaice and sole collected between 1992-1993 have been analysed for the levels of chlorinated pesticides and polychlorinated biphenyls (PCBs). Considering the diversity in the sizes and assortment, locations, and time of catch, the samples are deemed to represent the normal fish variety available to the local people at various seasons of the year. Virtually all the samples contained CB-153 levels below the new established maximum limit of 0.1 mg/kg fresh weight. Results are compared with those obtained between 1985 and 1993. Neither the total PCB (on fat weight basis) nor CB 153 as a marker showed any clear trend for most of the fish species analysed, particularly for the short period 1991-1993. The pesticides, on the other hand, showed a rather good downward trend up till 1991; some of them seem to have virtually attained a steady state after 1991.

Importance of a novel oxidative mechanism for elimination of intracellular cholesterol in humans

We have recently demonstrated that cultured human alveolar macrophages efficiently convert cholesterol into excretable 27-oxygenated products. We show here that increasing the intracellular concentration of cholesterol by a factor of 10 leads to about a twofold increase in the excretion of 27-oxygenated products from cultured macrophages. Inhibition of the sterol 27-hydroxylase caused a significant intracellular accumulation of cholesterol. A direct comparison was made between flux of cholesterol and 27-oxygenated products from macrophages preloaded with [4-14C]cholesterol. Under the specific conditions employed with fetal calf serum in the culture medium, the flux of 27-oxygenated products was about 10% of that of cholesterol. Since the sterol 27-hydroxylase, which converts cholesterol to 27-oxygenated products, is present in many cell types, we suggest that 27-oxygenation is a general mechanism for removal of intracellular cholesterol. To evaluate this hypothesis, we measured the net uptake by the human liver of circulating 27-oxygenated products, which was found to be about 20 mg/24 h. This uptake corresponds to approximately 4% of the bile acid production, assuming quantitative conversion into bile acids. It is concluded that the 27-hydroxylase pathway is of significance for elimination of extrahepatic cholesterol.

Allergen challenge-induced entry of alpha 2-macroglobulin and tryptase into human nasal and bronchial airways

BACKGROUND

Microvascular-epithelial exudation of bulk plasma may characterize inflammatory airway diseases. This study compares the acute allergen challenge-induced mast cell and exudative responses in nasal and bronchial airways. The focus is on alpha 2-macroglobulin as an index of luminal entry of plasma exudates.

METHODS

Separate nasal and bronchial allergen challenges were carried out outside the pollen season in eight patients with pollen-induced seasonal allergic rhinitis. The levels of different-sized plasma proteins (albumin molecular weight, 66,000 d and alpha 2-macroglobulin molecular weight, 725,000 d) and tryptase were determined in pre- and postchallenge nasal lavage and bronchoalveolar lavage (BAL) fluids. Diluent and increasing doses of allergen were sprayed into the right nasal cavity, and each challenge was followed by a nasal lavage (volume, 15 ml) with a "nasal pool" device (recovery, > 80%). Endobronchial allergen challenge (individual doses) and BAL (volume, 2 x 25 ml) were performed in a lobe bronchus through a fiberoptic bronchoscope (recovery, 30%). Saline challenge and BAL were carried out in the contralateral lung as control.

RESULTS

The levels of albumin, alpha 2-macroglobulin, and tryptase increased dose-dependently in postchallenge nasal lavage fluids (p < 0.05) and correlated to nasal symptoms. In particular, albumin and alpha 2-macroglobulin correlated (r = 0.98, p < 0.001). Both alpha 2-macroglobulin and tryptase, but not albumin, were increased in BAL fluids from the allergen-challenged side (p < 0.05).

CONCLUSION

Local allergen challenge causes luminal entry of tryptase and alpha 2-macroglobulin in the nose and bronchi of patients with allergy. We suggest that mast cell and plasma exudation responses may be similar in human nasal and bronchial airways and that albumin levels (in BAL fluids) may not well reflect the exudation process in bronchial airways.

Glass-ceramic-coated titanium hip endoprosthesis. Experimental study in rabbits

Titanium alloy hip endoprostheses coated with a bioactive glass ceramic (BGC) were followed in rabbits. All test endoprostheses remained stable, and image analysis showed an average of 78% bonding of the BGC-coated implants to bone at 52 weeks. The uncoated Ti-alloy controls demonstrated an average of 37% bone coverage after 52 weeks. By scanning electron microscopy the thickness of the BGC reaction layer was found to stabilize at 60 microns after bioactive bone bonding. The results indicate that the BGC coating must be thicker than the reaction layer to prevent detachment from the core metal.

Atherosclerosis and sterol 27-hydroxylase: evidence for a role of this enzyme in elimination of cholesterol from human macrophages

27-Hydroxycholesterol was found in surprisingly high amounts in atherosclerotic human femoral arteries. When human macrophages were cultured in a medium containing serum, there was a significant transfer of 27-hydroxy-cholesterol and 3 beta-hydroxy-5-cholestenoic acid from the cells into the medium. Sterol 27-hydroxylase (EC 1.14.13.15) is likely to be responsible for formation of the two products as shown by use of immunoblotting, a specific inhibitor, and the 18O-labeling technique. Sterol 27-hydroxylase has the unusual ability to hydroxylate the same methyl group three times to give a carboxylic acid; thus, 3 beta-hydroxy-5-cholestenoic acid is likely to be a direct product of the enzyme. The production of these steroids increased after addition of cholesterol to the culture medium. By using deuterium-labeled cholesterol, it was ascertained that most of the oxidized products were formed from exogenous cholesterol taken up by the cells. 27-Hydroxycholesterol and 3 beta-hydroxy-5-cholestenoic acid are present in the circulation and are efficiently converted into bile acids in human liver. It is suggested that conversion of cholesterol into 27-hydroxycholesterol and 3 beta-hydroxy-5-cholestenoic acid represents a general defence mechanism for macrophages and possibly also other peripheral cells exposed to cholesterol. Absence of this defence mechanism may contribute to the premature atherosclerosis known to occur in patients with sterol 27-hydroxylase deficiency (cerebrotendinous xanthomatosis).