Magnetic resonance imaging of acute intramedullary myelopathy: radiological differential diagnosis for the on-call radiologist.

Spinal cord disease is often viewed as having a poor outcome. Although in certain conditions this is true, non-traumatic myelopathy encompasses a vast array of diseases some of which are exquisitely responsive to treatment. Accurate diagnosis becomes important as damage is often progressive and long-term disability and morbidity is related to the degree of neurological impairment when the diagnosis is reached. Out-of-hours magnetic resonance imaging (MRI) is generally requested and performed to ascertain whether there is spinal cord compression; however, there are other causes of a cord syndrome, which are more subtle. This review aims to provide a summary of the imaging features of non-traumatic intramedullary spinal cord emergencies, many of which may appear radiologically similar.

What is the natural history of nonoperated nonfunctioning pituitary adenomas?

BACKGROUND: Series of patients systematically investigating the outcome of clinically nonfunctioning pituitary adenomas (NFAs) not treated by surgery or radiotherapy during long follow-up periods are limited. Most reports involve the follow-up of selected cases of incidentally found lesions, rendering their results unreliable on the assessment of the pros and cons of a 'watch and wait' policy. OBJECTIVE: To investigate the outcome of a series of consecutive patients with presumed NFA (microadenoma or macroadenoma), who were not offered treatment at presentation (for a number of reasons) and were regularly followed up, and to identify possible factors predicting subsequent increase in tumour size. PATIENTS AND METHODS: All patients presenting to the Department of Endocrinology in Oxford between 1989 and 2005 with presumed NFA were studied retrospectively. Inclusion criteria were: (i) imaging features suggestive of a pituitary adenoma, (ii) no clinical and/or biochemical evidence of hormonal hypersecretion by the tumour, (iii) monitoring being the initial choice of management, and (iv) at least one repeat scan during the follow-up period. Subjects presenting with acute apoplexy were excluded. Follow-up management included clinical evaluation, assessment of the visual acuity and fields and imaging at regular intervals. The duration of observation was estimated from the dates of first and last scan. RESULTS: Forty subjects were included in the study [18 males/22 females, median age 52 years (range 18-89), 16 with microadenoma/24 with macroadenoma]. The mean follow-up period was 42 months (range 8-128). During the observation interval, 12.5% of the microadenomas and 50% of the macroadenomas increased in size. The 48-month probability for enlargement was 19% for the microadenomas and 44% for the macroadenomas. Among the subjects with tumour enlargement, 57% showed new or worse visual field defects (all had macroadenomas) and 21% showed chiasmatic involvement on imaging without visual deterioration (all had macroadenomas). New or worse visual field defects were found in 67% of the macroadenomas showing increase in size. No microadenoma enlarged to cause visual deterioration. In microadenomas, sex and age at presentation were not predictors of enlargement. In macroadenomas, sex, age, visual field defects or cavernous sinus invasion at presentation were not predictors of enlargement. CONCLUSIONS: The 'watch and wait' policy seems reasonable for microadenomas but is probably not a safe approach for macroadenomas, which appear to have a significant growth potential; in these cases, given the lack of established medical treatment, the decision for surgical intervention should balance the presence of significant comorbidities and the anaesthetic/peri-operative risks at presentation against the probability of tumour enlargement and its consequences, as well as the possible loss of advantages associated with early operation.

Human neutrophil gene expression profiling following xenogeneic encounter with porcine aortic endothelial cells: the occult role of neutrophils in xenograft rejection revealed.

The role of innate immune cells in the recognition and activation of xenogeneic endothelium has always been considered secondary to the initial insult of xenoreactive natural antibodies (XNA) and complement. It was argued, however, that innate immune cells are capable of recognizing and activating xenogeneic endothelium in the absence XNA and complement. Here, we show that porcine aortic endothelial cells (PAECs) activate human neutrophils directly. This contact-dependent activation causes a transient calcium rise leading to increased reactive oxygen metabolite (ROM) production. Neutrophil gene-expression profiling using an adenylate uridylate-rich element-based microarray revealed a dramatic change in the neutrophil gene profiles upon exposure to PAECs. The PAEC-dependent neutrophil transcriptional activity was further confirmed by real-time polymerase chain reaction, which revealed a rapid increase in the mRNA message of a number of inflammatory cytokines. The activation of human neutrophils by PAECs was independent of galactose alpha1,3-galactose (Galalpha1,3-gal) structures, as inclusion of saturating concentrations of anti-Galalpha1,3-gal l antibodies had no significant effect. Furthermore, this activation was inhibited in the presence of the calcium chelator 1,2-bis(O-aminophenyl-ethane-ethane)-N,N,N',N'-tetraacetic acid-acetoxymethyl ester and the ROM inhibitor diphelylene iodonium. Our data illustrate the direct activation of innate immune cells by PAECs in the absence of XNA and complement and suggest alternative recognition sites between PAECs and human innate immune cells.

Positive charges in a putative amphiphilic helix in the carboxyl-terminal region of the third intracellular loop of the luteinizing hormone/chorionic gonadotropin receptor are not required for hormone-stimulated cAMP production but are necessary for expression of the receptor at the plasma membrane.

The LH/CG receptor (LHR) is a member of the family of G protein-coupled receptors and activates Gs when stimulated by LH or CG. Studies from other G protein-coupled receptors have implicated the carboxyl-terminal region of the third intracellular loop as being involved in the activation of G proteins. It has been suggested that the potential ability of this region to form an amphiphilic helix, with positively charged residues aligned to one face, may be important for this biological activity. To test whether the positively charged lysine residues, and thus an amphiphilic helix, in the carboxyl terminal region of the rat LHR (rLHR) are indeed important in the activation of Gs by the rLHR, a mutant rLHR was constructed in which lysines 541, 544, and 557 were simultaneously substituted with alanines. Clonal 293 cells expressing comparable numbers of cell-surface recombinant wild type rLHR or rLHR(K541,544,547A) were generated. Cells expressing the mutant receptor-bound human CG (hCG) with the same high affinity as those expressing the wild type rLHR. Since the numbers of receptors and binding affinities between the two cell lines were comparable, any changes in basal or hCG stimulated cAMP production could readily be interpreted as an alteration in the mutant receptor's ability to activate Gs. It was found, however, that basal cAMP production, the concentration of hCG required to elicit half-maximal cAMP production, and the maximal levels of cAMP produced in response to hCG were all unchanged in cells expressing rLHR(K541,544,547A).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of truncations of the cytoplasmic tail of the luteinizing hormone/chorionic gonadotropin receptor on receptor-mediated hormone internalization.

The LH/CG receptor is a member of the family of G protein-coupled receptors and consists of a large N-terminal extracellular domain (which is responsible for binding hormone) attached to a region that spans the plasma membrane seven times, ending with an intracellularly located C-terminus. Binding of LH or human CG (hCG) to the LH/CG receptor causes a stimulation of adenylyl cyclase, presumably via activation of Gs. The binding of hormone also leads to its subsequent internalization by receptor-mediated endocytosis. In order to investigate the role of the cytoplasmic tail of this receptor in these events, we prepared a series of mutants in which progressively larger portions of the cytoplasmic tail were deleted. Deletion of 58 amino acids from the C-terminus, in which only 11 cytoplasmic residues remain, resulted in a receptor that was not expressed on the plasma membrane. Receptors rat LHR (rLHR)-t653 and rLHR-t631, in which 21 or 43 amino acids were removed, respectively, were properly expressed. These results suggest that a region(s) between residues 616 and 631 of the rLH/CG receptor are required for proper insertion and/or targeting of the receptor into the plasma membrane. Cells expressing rLHR-t653 or rLHR-t631 bound hCG with the same high affinity as cells expressing the full-length receptor, and basal levels of cAMP were the same among the cells. However, cells expressing the truncated receptors responded to hCG with approximately 2-fold greater levels of maximal cAMP accumulation than cells expressing the full-length receptor. Deletion of up to 43 amino acids from the C-terminus of the rLH/CG receptor had no deleterious effect on hCG internalization. In fact, mutants lacking 21 and 43 amino acids exhibited progressively faster rates of hCG internalization as compared to the full-length receptor. Once internalized, hCG was also degraded at a faster rate in cells expressing the truncated LH/CG receptors. Since hCG-stimulated cAMP stimulation and hCG internalization are retained by rLHR-t631, it can be concluded that the residues, not necessarily the same, required for these functions reside within the 26 amino acids of the cytoplasmic tail closest to the seventh transmembrane helix and/or residues within the intracellular loops. Our data show, however, that both hCG-stimulated cAMP production and hCG internalization are enhanced by the removal of the distal portion of the cytoplasmic tail.

Immobilization of rolling NK cells on platelet-borne P-selectin under flow by proinflammatory stimuli, interleukin-12, and leukotriene B4.

Recruitment of leukocytes from bloodstream to extrahematic sites is tightly regulated by a variety of adhesion molecules that are expressed on the leukocytes and the vessel walls. In this manuscript, we describe the interactions between natural killer (NK) cells and activated, autologous platelets under physiologic flow. We found that surface-adherent human platelets are capable of recruiting human NK cells from flow and that this recruitment is characterized by an initial tethering followed by a rolling phase. Both phases were dependent on the adhesion molecule P-selectin and its counter-ligand on the NK cells (P-selectin glycoprotein ligand 1). Activation of rolling NK cells with inflammatory mediators commonly found in atherosclerotic plaques (interleukin-12 and leukotriene B4) causes immediate cessation of the rolling process and conversion to stationary adhesion. Blocking antibodies to the adhesion molecules membrane-activated complex-1 and leukocyte function antigen-1 inhibited this conversion. Our data suggest that platelets deposited at sites of vascular injury may provide an alternative substrate to endothelial cells for initial recruitment of NK cells to the vessel wall. This may result in extravasation of the NK cells if the appropriate chemotactic signal is applied. These data implicate the P-selectin and integrin family of adhesion molecules in the recruitment of NK cells to atherosclerotic sites.

Monomeric human IgE evokes a transient calcium rise in individual human neutrophils.

Digital fluorescence calcium imaging was used to investigate and identify the primary biological responses of human neutrophils to monomeric immunoglobulin E (IgE). Treatment of neutrophils with IgE caused a transient rise in the level of intracellular calcium that was inhibited by pertussis toxin. The calcium rise was due mainly to release from an intracellular membrane-enclosed store that is also sensitive to the chemotactic peptide formyl-Met-Leu-Phe. The IgE-induced calcium transient was independent of Fc gamma receptors and of Fc epsilon receptor ligation. Our data suggest that the mere binding of IgE to neutrophils is sufficient to evoke a biological response without the need for IgE/receptor cross-linking.

Evidence that the FSH receptor itself is not a calcium channel.

FSH has been shown to stimulate the uptake of calcium in cultured rat Sertoli cells, resulting in an increase in cytosolic calcium concentrations. One possibility which has been put forth is that the FSH receptor per se may act as a calcium channel. This is all the more tantalizing given the proposed structure of this receptor which, like all other G protein-coupled receptors, is thought to have the putative transmembrane helices forming a bundle-like structure in the plasma membrane. To test whether the FSH receptor could function as a calcium channel, we performed whole-cell voltage clamp experiments on 293 and 293F(wt1) cells, which are a clonal line of 293 cells expressing high levels of rat FSH receptors. The 293 cells, which do not express FSH receptors, were found to lack any detectable inward calcium currents, and therefore, serve as an excellent model for transfecting with potential calcium conducting FSH receptors. When the 293F(wt1) cells were then tested, no inward calcium currents could be detected in either control or FSH-stimulated cells. These results suggest that the FSH receptor itself is not a calcium channel and, therefore, FSH must be stimulating endogenous calcium channels in rat Sertoli cell plasma membranes.

Effect of Graves' IgG on gene transcription in human thyroid cell cultures. Thyroglobulin gene activation.

In Graves' disease (GD) the presence of antibodies to the thyroid stimulating hormone (TSH) receptor leads to stimulation of the thyroid gland. The thyroid stimulating activity of Graves' IgG is normally ascertained by bioassays measuring cAMP production. We have investigated the effect of Graves' IgG on the quantitative activation of thyroglobulin (TG) gene in cultured human thyroid cells by RNA hybridisation. TG mRNA expression was activated by TSH and Graves' IgG. Nuclear transcription assays showed that the increase in cytoplasmic mRNA levels was due to increased transcription of TG specific mRNA in nuclei of thyroid cells. Whilst TSH led to a dose dependent increase in TG mRNA levels, Graves' IgG led to a variable activation of TG gene. A significant correlation between the increased TG mRNA transcription and cAMP production was observed with Graves' IgG. Thus the activation of the TG gene by Graves' IgG occurs in parallel with elevation of cAMP.

Activation of the thyroid peroxidase gene in human thyroid cells: effect of thyrotrophin, forskolin and phorbol ester.

The enzyme thyroid peroxidase (TPO) plays a central role in thyroid hormone synthesis and is the target for the autoimmune attack in lymphocytic thyroiditis. We have examined the activation of the TPO gene in cultured human thyrocytes using slot-blot hybridization with a synthetic 40 mer oligonucleotide probe derived from the nucleotide sequence of the human TPO gene. The oligonucleotide probe was shown by Northern blotting to hybridize specifically to an approximately 3 kb RNA species from thyroid tissue of patients with Graves' disease, but not to RNA preparations from human or bovine retinal tissue, providing compelling evidence for the specificity of the probe for TPO mRNA. Addition of TSH (10 mU/ml) to primary thyroid cultures for 4 h led to increased TPO mRNA levels which were maximal after 48 h and significantly higher than basal even after 7 days of co-culture. Activation of TPO mRNA by TSH showed dose dependency over a wide range (0.01-100 mU/ml), with a maximal effect at 10 mU TSH/ml in cells cultured for a period of 72 h. Comparison of TPO mRNA levels with the accumulation of thyroglobulin mRNA levels following stimulation by TSH indicated that the induction of the gene encoding thyroglobulin precedes transcription of the TPO gene. The adenylate cyclase activator forskolin (1-100 microM) mimicked TSH in increasing TPO mRNA levels whilst, in contrast, the phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA; 0.01-1 microM) led to levels of TPO mRNA that were lower than basal. Thus TSH induces a specific dose-dependent activation of TPO mRNA which is mimicked by agents which increase cyclic AMP. In contrast, TPA-induced activation of protein kinase C inhibits this response.

Expression of a human thyrotrophin receptor fragment in Escherichia coli and its interaction with the hormone and autoantibodies from patients with Graves' disease.

Graves' disease is an autoimmune thyroid disease characterized by the presence of pathogenic autoantibodies to the TSH receptor (TSH-R). By using polymerase chain reaction, the extracellular region of the human TSH-R cDNA has been amplified and used to prepare recombinant TSH-R (extracellular) protein fused with glutathione-S-transferase (GST). Purification of the recombinant TSH-R (extracellular)-GST fusion protein was achieved by preparative gel electrophoresis in SDS or by preparative isoelectric focusing in urea. Following removal of SDS by detergent exchange or urea by dialysis, the purified recombinant receptor preparations were assessed for binding to the hormone or to autoantibodies from Graves' disease patients. The purified recombinant receptor preparations fail to show any binding to the hormone or autoantibodies either by inhibition of binding assays or by immunoblotting. The results imply that the correct folding and/or post-translational modifications of the polypeptide chain which are not achieved in recombinant proteins produced in Escherichia coli may be important for the binding of the hormone or Graves' disease autoantibodies to the TSH-R. The recombinant receptor prepared in this manner will be useful for immunological and cellular investigations in patients with Graves' disease.

The thyrotrophin hormone receptor of Graves' disease: overexpression of the extracellular domain in insect cells using recombinant baculovirus, immunoaffinity purification and analysis of autoantibody binding.

Since the cloning of the TSH receptor (TSH-R), the target autoantigen of Graves' disease, the receptor has been expressed in a variety of eukaryotic cells to obtain a functional molecule. Despite this success, the levels of receptor expression have been marginally higher than the extremely low levels found in thyroid cells, preventing any progress on the purification of the molecule. In this study, the large extracellular region of the TSH-R, without the membrane spanning segments, has been expressed in insect cells using recombinant baculovirus to generate substantial quantities of the receptor protein. A monoclonal antibody previously generated to a bacterial TSH-R fusion protein was used to characterize and monitor the expression of the truncated receptor in insect cells. Two polypeptides of 63 and 49 kDa were recognized as the components of the truncated recombinant receptor. The 63 kDa protein was shown to be the glycosylated form of the smaller, 49 kDa, component. Expression in different insect cell lines showed that an increase in expression of approximately tenfold was apparent in High Five cells when compared with Sf21 cells. Very small quantities of the truncated receptor were secreted by the three insect cell lines examined, with the majority of the molecule being retained within the cells. Immunoaffinity purification of milligram quantities of the truncated receptor was achieved using the monoclonal antibody. The availability of the purified TSH-R has allowed the establishment of an enzyme-linked immunosorbent assay to measure autoantibodies in the sera of patients with Graves' disease. Although the truncated receptor interacts with autoantibodies, our results show that it does not bind TSH and differs in this respect from other glycoprotein hormone receptors.

Alpha-gal-independent dual recognition and activation of xenogeneic endothelial cells and human naïve natural killer cells.

BACKGROUND: Interaction between vascularized xenograft and host immune system is thought to occur via Galactose alpha (1,3) Galactose (Gala 1,3 gal) structures decorating the xenograft. METHODS: We raised anti-Gala 1,3 gal-BSA polyclonal antibodies in baboons and investigated effect(s) of these antibodies as well as soluble Gala 1,3 gal-BSA on human naive natural killer (NK) cell interactions with porcine aortic endothelial cells. RESULTS: We demonstrate that human naive (unstimulated) NK cells recognize xenogeneic endothelial cells under conditions where binding to the Gala 1,3 gal structures is minimized by the presence of blocking anti-Gala 1,3 gal IgG or soluble Gala 1-3 gal and in the absence of xenoreactive natural antibodies and complement. After xenogeneic encounter both endothelial cells and human NK cells are activated. Endothelial cell activation is rapid and is manifested initially by an intraendothelial calcium transient and subsequently by expression of P-selectin and vascular endothelial cell adhesion molecule-1 on the xenoendothelium surface. NK cell activation is manifested by increased expression of perforin and increased cytotoxicity towards the xenoendothelium. Neither recognition nor activation of the xenoendothelium was affected by the introduction of either anti-Gala 1,3 gal IgG or soluble Gala 1-3 gal. CONCLUSION: Our data provide evidence that innate immune cells, such as NK cells, recognize and activate xenoendothelial cells independently of Gala 1-3 gal structures and raise the possibility of novel interactive sites on both human naive NK cells and discordant xenogeneic endothelium.

Ca(2+)-dependent production of reactive oxygen metabolites by human neutrophils in response to fluorinated propranolol analogues.

Fluorinated analogues of propranolol, namely trifluoroethyl propranolol (F3), pentafluoropropyl propranolol (F5), and heptafluorobutyl propranolol (F7), were found to induce reactive oxygen metabolite (ROM) production in human neutrophils in a dose-dependent manner. Preincubation of neutrophils with the calcium chelator BAPTA-AM or the tyrosine kinase inhibitor genistein inhibited this ROM production. Direct measurements of intracellular calcium revealed that these analogues caused a transient increase in intracellular calcium. In addition, these fluorinated analogues of propranolol caused a transient increase in actin polymerization. The effects of these compounds were found to be dependent upon the degree of fluorination of the parent compound. Propranolol, on the other hand, had no direct effect on ROM, calcium, or actin polymerization when added alone to neutrophils, although it did modify responses of cells to various stimuli. Whereas ROM production induced by the chemotactic peptide formyl-methionyl-leucyl-phenylalanine was enhanced in a dose-dependent manner, the response to the particulate stimulus, latex beads, was abolished.

A 102 kDa subunit of a Golgi-associated particle has homology to beta subunits of trimeric G proteins.

We have identified a 102 kDa protein, p102, which is found on the cytoplasmic face of Golgi membranes, exocytic transport vesicles and in the cytosol. A monoclonal antibody that cross-reacts with p102 is able to immunoprecipitate a 500-600 kDa protein complex containing p102 and additional subunits. The composition of this p102-containing protein complex resembles that of the Golgi coatomer complex, which constitutes the coat of non-clathrin coated vesicles. One of the subunits of the p102 complex reacts with a monoclonal antibody that detects beta-COP, a subunit of the Golgi coatomer complex. Like beta-COP, p102 exists in a brefeldin A-sensitive association with Golgi membranes. The sequence of p102 contains an N-terminal domain composed of six repeats which are similar to those found in the beta subunit of trimeric G proteins and other regulatory proteins. We suggest that p102 may be involved in regulating membrane traffic in the constitutive exocytic pathway.

Autoantibody stimulation of the human thyrotropin receptor: regulation of adenylate cyclase activity, thyroglobulin and thyroid peroxidase mRNA levels in primary cultures of Graves' thyroid tissue.

The effects of immunoglobulin preparations from hyperthyroid Graves' disease patients on primary cultures of thyroid cells have been studied at the mRNA level. Autoantibodies to the thyrotropin (TSH) receptor from these patients, which had been initially characterized by their ability to stimulate adenylate cyclase and inhibit the binding of radiolabelled TSH to thyroid membrane preparations, were studied for their effects on thyroglobulin and thyroid peroxidase mRNA levels. Incubation of thyroid cells with TSH receptor autoantibodies from different Graves' disease patients for 48 h led to time- and dose-dependent increases in the levels of thyroid peroxidase and thyroglobulin mRNA in primary cultures of thyrocytes. The incomplete correlation between G protein-linked adenylate cyclase activation and thyroid mRNA elevation indicates the possibility of the involvement of alternative second messenger pathways in the regulation of thyroid cell function and differentiation.

ADP-ribosylation factor 1-regulated phospholipase D activity is localized at the plasma membrane and intracellular organelles in HL60 cells.

ADP-ribosylation factor (ARF), a small GTPase required for vesicle formation, has been identified as an activator of phospholipase D (PLD), thus implying that PLD is localized at intracellular organelles. HL60 cells were prelabelled with [14C]acetate for 72 h and, after disruption, fractionated on a linear sucrose gradient. ARF1-regulated PLD activity in each fraction was assessed by measurement of phosphatidylethanol production. Two peaks of activity were identified, coincident with markers for Golgi/endoplasmic reticulum/granules (endomembranes) and plasma membrane respectively. Analysis of the fractions using exogenous phosphatidylcholine as substrate confirmed the presence of ARF1-dependent PLD activity in endomembranes and plasma membrane, and also identified an additional activity in the cytosol. In formyl-Met-Leu-Phe-stimulated cells, PLD activity as assessed by phosphatidylethanol formation was also associated with both the plasma membrane and endomembranes. Since ARF1-regulated PLD activity requires phosphatidylinositol 4,5-bisphosphate (PIP2), the distributions of inositol lipids and the kinases responsible for lipid phosphorylation were examined. PIP2 was highly enriched at the plasma membrane, whereas phosphatidylinositol (PI) and phosphatidylinositol 4-phosphate (PI4P), the precursors for PIP2 synthesis, were found predominantly at endomembranes. The distribution of PI 4-kinase and PI4P 5-kinase activities confirmed the plasma membrane as the major site of PIP2 production. However, endomembranes possessed substantial PI 4-kinase activity and some PI4P 5-kinase activity, illustrating the potential for PIP2 synthesis. It is concluded that:(1) ARF1-regulated PLD activity is localized at endomembranes and the plasma membrane, (2) PIP2 is available at both membrane compartments to function as a cofactor for ARF-regulated PLD, and (3) in intact cells, formyl-Met-Leu-Phe stimulates PLD activity at endomembranes as well as plasma membrane.

Postpartum thyroid dysfunction in Mid Glamorgan.

A high prevalence of postpartum thyroid dysfunction has been reported in several countries, but there have been no systematic studies of its prevalence in Britain. Among a group of 901 consecutive, unselected pregnant women thyroid autoantibodies were detected in 117 (13%) at booking. The clinical course of postpartum thyroid dysfunction, factors associated with its development, and its likely prevalence were defined in 100 of these women with thyroid antibodies and 120 women with no such antibodies who were matched for age. None of the women had a history of autoimmune thyroid disease. Normal reference ranges for thyroid function during pregnancy and post partum were established in the 120 women negative for thyroid antibodies. On the basis of these observations postpartum thyroid dysfunction was observed in 49 (22%) of the 220 women studied, and the prevalence in the total group of 901 women was estimated to be 16.7%. Thyroid dysfunction, mainly occurring in the first six months post partum, was usually transient and included both destruction induced hyperthyroidism and hypothyroidism. The development of the syndrome was significantly related to smoking more than 20 cigarettes a day and the presence of thyroid microsomal autoantibodies at booking. Of the 16 women with a family history of thyroid disease in whom thyroid microsomal autoantibody activity was detectable at booking, 11 developed thyroid dysfunction. Age, parity, presence of goitre at presentation, duration of breast feeding, and the sex and birth weight of the infant were not associated with the development of postpartum thyroid dysfunction. The mood changes experienced by women post partum may in part be associated with altered thyroid function during this time.

Activation of naive xenogeneic but not allogeneic endothelial cells by human naive neutrophils: a potential occult barrier to xenotransplantation.

Here we demonstrate that human neutrophils, the predominant circulating leukocytes in intimate contact with endothelial cells lining the vasculature, directly recognize xenogeneic endothelium independently of xenoreactive natural antibody and complement. A rapid and calcium-dependent activation of native (unstimulated) xenogenic endothelial cells by human neutrophils leads to 1) translocation of P-selectin from the Wiebel-Palade bodies to the surface of xenogeneic endothelial cells, 2) increased synthesis and expression of vascular cell adhesion molecule-1 on the xenogeneic endothelial cells, and 3) enhanced killing of the xenogeneic endothelium by natural killer cells. Our data directly implicate naive neutrophils as major early participants in xenograft recognition and endothelial activation independent of xenoreactive natural antibodies and complement.

Aeroallergens and viable microbes in sandstorm dust. Potential triggers of allergic and nonallergic respiratory ailments.

Aeroallergens and antigens in sandstorm dust, extracts of which were skin prick test (SPT) positive in allergic patients, were detected by rocket immunoelectrophoresis and ELISA. Fungi and bacteria isolated by agar settle plates and soil dilution and soil washing methods were enumerated and identified. Cat dander, Acacia, Alternaria, Aspergillus, Chenopodium, Cladosporium, Bermuda grass, Pithecellobium, Prosopis, Rumex, cultivated rye, and Washingtonia palm allergens were detected by both methods. Viable microbes including 1892 +/- 325 colony-forming units (cfu) of bacteria, and 869 +/- 75 cfu of fungi were isolated per gram of dust by the soil dilution method. Randomly selected microbial colonies on streaking and subculture were found to consist of between two and seven mixed colonies. Fungi including Alternaria, Aspergillus, Botrytis, Cladosporium, Mortierella, Mucor, Mycelia sterilia, Penicillium, Pythium, Ulocladium, Verticillium, and some yeasts were isolated. Actinomyces, Bacillus, Pseudomonas, and mostly coagulase-negative Staphylococcus species were identified, but the bulk of unidentified bacterial isolates were mainly mixed colonies of rods, cocci, coccobacilli, and some filamentous types. Six-hour agar settle-plate counts during sandstorms were 100 and 40% higher for bacteria and fungi, respectively, than without sandstorms. The most abundant aeroallergens were those of Acacia, Alternaria, Aspergillus, Bermuda grass, Cladosporium, cultivated rye, Prosopis, and cat dander. Pithecellobium dulce, Rumex crispus, and Washingtonia palm allergens were detectable for the first time in Riyadh. IgE reactivities of the dust in man were demonstrated by ELISA using sera from atopic, exposed, and normal subjects. These results indicate that sandstorm dust is a prolific source of potential triggers of allergic and nonallergic respiratory ailments, and the methods mentioned here should be routinely used for quick sampling of the environment.