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Biomedical subjects

David A Brown

Publications and source records attributed to David A Brown.

At least 37 records · Page 2Linked to original sources

Cardioprotection afforded by chronic exercise is mediated by the sarcolemmal, and not the mitochondrial, isoform of the KATP channel in the rat.

This study was conducted to examine the role of myocardial ATP-sensitive potassium (K(ATP)) channels in exercise-induced protection from ischaemia-reperfusion (I-R) injury. Female rats were either sedentary (Sed) or exercised for 12 weeks (Tr). Hearts were excised and underwent a 1-2 h regional I-R protocol. Prior to ischaemia, hearts were subjected to pharmacological blockade of the sarcolemmal K(ATP) channel with HMR 1098 (SedHMR and TrHMR), mitochondrial blockade with 5-hydroxydecanoic acid (5HD; Sed5HD and Tr5HD), or perfused with buffer containing no drug (Sed and Tr). Infarct size was significantly smaller in hearts from Tr animals (35.4 +/- 2.3 versus 44.7 +/- 3.0% of the zone at risk for Tr and Sed, respectively). Mitochondrial K(ATP) blockade did not abolish the training-induced infarct size reduction (30.0 +/- 3.4 versus 38.0 +/- 2.6 in Tr5HD and Sed5HD, respectively); however, sarcolemmal K(ATP) blockade completely eradicated the training-induced cardioprotection. Infarct size was 71.2 +/- 3.3 and 64.0 +/- 2.4% of the zone at risk for TrHMR and Sed HMR. The role of sarcolemmal K(ATP) channels in Tr-induced protection was also supported by significant increases in both subunits of the sarcolemmal K(ATP) channel following training. LV developed pressure was better preserved in hearts from Tr animals, and was not influenced by addition of HMR 1098. 5HD decreased pressure development regardless of training status, from 15 min of ischaemia through the duration of the protocol. This mechanical dysfunction was likely to be due to a 5HD-induced increase in myocardial Ca2+ content following I-R. The major findings of the present study are: (1) unlike all other known forms of delayed cardioprotection, infarct sparing following chronic exercise was not abolished by 5HD; (2) pharmacological blockade of the sarcolemmal K(ATP) channel nullified the cardioprotective benefits of exercise training; and (3) increased expression of sarcolemmal K(ATP) channels was observed following chronic training.

ATP-Binding Cassette Transporters↗

Modulation of gene expression in neonatal rat cardiomyocytes by surface modification of polylactide-co-glycolide substrates.

Myocardial tissue engineering presents a potential treatment option for heart disease. Cardiomyocytes isolated at various stages of development retain the ability to form contractile networks in vitro, which suggests that it should be possible to reconstitute viable myocardium given the appropriate architecture, stimuli, and cardiomyogenic cell source. This study investigates the effects of modifying substrate surface energy (by plasma etching) and protein coating (by fibronectin adsorption) on neonatal rat ventricular myocyte (NRVM) function. Primary NRVMs were cultured for 96 h on modified and control films of a common degradable polymer, polylactide-co-glycolide. Cultures were analyzed for cell spreading, protein content, and mRNA expression of atrial natriuretic factor and beta-myosin heavy chain. The results demonstrate that NRVMs cultured on etched films significantly increased in spreading, myofibril development, protein content, and gene expression of atrial natriuretic factor and beta-myosin heavy chain compared with unetched films, and that this surface energy effect is overwhelmed by the addition of fibronectin. Conclusions from this study are that surface energy and protein adsorption influence the gene expression of adherent NRVMs, and may be important for modulating the function of engineered myocardium.

Animals↗

Relationship between membrane phosphatidylinositol-4,5-bisphosphate and receptor-mediated inhibition of native neuronal M channels.

The relationship between receptor-induced membrane phosphatidylinositol-4'5'-bisphosphate (PIP2) hydrolysis and M-current inhibition was assessed in single-dissociated rat sympathetic neurons by simultaneous or parallel recording of membrane current and membrane-to-cytosol translocation of the fluorescent PIP2/inositol 1,4,5-trisphosphate (IP3)-binding peptide green fluorescent protein-tagged pleckstrin homology domain of phospholipase C (GFP-PLCdelta-PH). The muscarinic receptor agonist oxotremorine-M produced parallel time- and concentration-dependent M-current inhibition and GFP-PLCdelta-PH translocation; bradykinin also produced parallel time-dependent inhibition and translocation. Phosphatidylinositol-4-phosphate-5-kinase (PI5-K) overexpression reduced both M-current inhibition and GFP-PLCdelta-PH translocation by both oxotremorine-M and bradykinin. These effects were partly reversed by wortmannin, which inhibits phosphatidylinositol-4-kinase (PI4-K). PI5-K overexpression also reduced the inhibitory action of oxotremorine-M on PIP2-gated G-protein-gated inward rectifier (Kir3.1/3.2) channels; bradykinin did not inhibit these channels. Overexpression of neuronal calcium sensor-1 protein (NCS-1), which increases PI4-K activity, did not affect responses to oxotremorine-M but reduced both fluorescence translocation and M-current inhibition by bradykinin. Using an intracellular IP3 membrane fluorescence-displacement assay, initial mean concentrations of membrane [PIP2] were estimated at 261 microm (95% confidence limit; 192-381 microm), rising to 693 microm (417-1153 microm) in neurons overexpressing PI5-K. Changes in membrane [PIP2] during application of oxotremorine-M were calculated from fluorescence data. The results, taken in conjunction with previous data for KCNQ2/3 (Kv7.2/Kv7.3) channel gating by PIP2 (Zhang et al., 2003), accorded with the hypothesis that the inhibitory action of oxotremorine-M on M current resulted from depletion of PIP2. The effects of bradykinin require additional components of action, which might involve IP3-induced Ca2+ release and consequent M-channel inhibition (as proposed previously) and stimulation of PIP2 synthesis by Ca2+-dependent activation of NCS-1.

Animals↗

Transforming growth factor-beta1 immobilises dendritic cells within skin tumours and facilitates tumour escape from the immune system.

Human skin tumours often regress spontaneously due to immune rejection. Murine skin tumours model this behaviour; some regress and others progress in syngeneic immunocompetent hosts. Previous studies have shown that progressor but not regressor skin tumours inhibit dendritic cell (DC) migration from the tumour to draining lymph nodes, and transforming growth factor-beta1 (TGF-beta1) has been identified as a responsible factor. To determine whether increased production of TGF-beta1 in the absence of other differences inhibits DC migration from the tumour and enables it to evade immune destruction, a murine regressor squamous cell carcinoma clone was transfected with the gene for TGF-beta1. This enhanced growth in vitro and in vivo, causing it to become a progressor. TGF-beta1 transfection reduced the number of infiltrating DCs by about 25%. Quantitation of CD11c+ E-cadherin+ (epidermally derived) DCs in lymph nodes determined that TGF-beta1 reduced the number of DCs that migrated from the tumour to undetectable levels. This was supported by showing that TGF-beta1 reduced DC migration from cultured tumour explants by greater than tenfold. TGF-beta1 transfection also reduced the number of infiltrating CD4 and CD8 T cells. Thus, TGF-beta1 production by skin tumours is sufficient to immobilise DCs within the tumour, preventing their migration to lymph nodes. This reduces the number of T cells that infiltrate the tumour, preventing regression. Thus, TGF-beta1 is a key regulator of whether skin tumours regress or progress.

Animals↗

The propeptide mediates formation of stromal stores of PROMIC-1: role in determining prostate cancer outcome.

The extracellular matrix (ECM) is a reservoir of cellular binding proteins and growth factors that are critical for normal cell behavior, and aberrations in the ECM invariably accompany malignancies such as prostate cancer. Carcinomas commonly overexpress macrophage inhibitory cytokine 1 (MIC-1), a proapoptotic and antitumorigenic transforming growth factor-beta superfamily cytokine. Here we show that MIC-1 is often secreted in an unprocessed propeptide containing form. It is variably processed intracellularly, with unprocessed forms being secreted from several tumor lines, including prostate carcinoma lines, PC-3 and LNCaP. Once secreted, only unprocessed proMIC-1 binds ECM, demonstrating for the first time the occurrence of extracellular stores of MIC-1. The propeptide mediates this association via its COOH-terminal 89 amino acids. Xenograft models bearing tumors secreting various engineered forms of MIC-1 show that the propeptide regulates the balance between ECM stores and circulating serum levels of mature MIC-1 in vivo. The absence of propeptide results in approximately 20-fold increase in serum MIC-1 levels. The significance of stromal MIC-1 stores was evaluated in prostate cancer tissue cores, which show major variation in stromal levels of MIC-1. Stromal MIC-1 levels are linked to prostate cancer outcome following radical prostatectomy, with decreasing stromal levels providing an important independent predictor of disease relapse. In low-grade localized prostate cancer (Gleason sum score < or = 6), the level of MIC-1 stromal stores was the best predictor of future relapse when compared with all other clinicopathologic variables. The secretion and ECM association of unprocessed proMIC-1 is likely to play a central role in modulating local bioavailability of MIC-1 which can affect patient outcome in prostate cancer and other epithelial tumors.

Animals↗

Susceptibility of the heart to ischaemia-reperfusion injury and exercise-induced cardioprotection are sex-dependent in the rat.

The cardioprotective effects of short-term exercise against myocardial ischaemia-reperfusion injury in male and female rats were examined. We subjected male and female rats to 0 (Sed; n = 8 males and 8 females), 1 (1 day; n = 10 males and 8 females), or 5 (5 day; n = 6 males and 6 females) days of treadmill running. Langendorff-perfused hearts underwent 1 h of regional ischaemia and 2 h of reperfusion, and infarct size (expressed as a percentage of the zone at risk; ZAR), left ventricular pressure development, and coronary flow were measured for each heart. Preischaemic pressure development and coronary flow did not differ between the sexes nor were they influenced by exercise. Sed females had significantly smaller infarct sizes (25 +/- 3%) than Sed male hearts (37 +/- 3%; P < 0.001). Short-term running significantly reduced infarct size following 1 day (27 +/- 3%; P < 0.05) and 5 days (30 +/- 4%; P < 0.10) of exercise in males. One day of running did not reduce infarct size in females (19 +/- 3%; P = NS), but 5 day females did show a significant reduction in infarct size (13 +/- 2%; P < 0.05). There was no relationship between postischaemic coronary vascular hyperaemia and infarct size across sexes or exercise training groups. Hearts from Sed females exhibited significantly higher manganese superoxide dismutase (MnSOD) protein expression than hearts from Sed males, but short-term exercise (neither 1 nor 5 days) did not alter MnSOD protein in either sex. Increased sarcolemmal ATP-sensitive K(+) (K(ATP)) channel subunit protein expression (SUR2A and/or K(ir)6.2) correlated closely with sex-dependent and exercise-acquired protection against myocardial infarction. These data indicate that: (1) sex-dependent and exercise-induced differences in the susceptibility of the heart to ischaemia-reperfusion injury are not associated with improved coronary flow or postischaemic hyperaemia; (2) increased MnSOD protein expression is not necessary for exercise-induced protection from infarction; and (3) one possible mechanism for sex-dependent and exercise-mediated reductions in infarct size involves an increased protein expression of cardiac sarcolemmal K(ATP) channels.

Animals↗

After sun reversal of DNA damage: enhancing skin repair.

UV-induced DNA damage has been directly linked to skin cancer, and DNA repair is an important protection against this neoplasm. This is illustrated by the genetic disease xeroderma pigmentosum wherein a serious defect in DNA repair of cyclobutane pyrimidine dimers dramatically increases the rate of skin cancer. In other instances in which skin cancer rates are elevated, deficits in DNA repair may also be one of the causal factors. For example, solid organ transplant patients have elevated rates of skin cancer that are correlated with the dose and length of exposure to immunosuppressive drugs (predominantly cyclosporine A (CsA) and ascomycin (FK506)-related tacrolimus). We have found that treatment of cultured epidermal cells with CsA or ascomycin inhibits their removal of DNA damage by about 20% at 24 h. In a further example, people with a polymorphism in the DNA repair gene 8-oxo-guanine glycosylase (OGG1) have an increased risk of skin cancer. We have found that the cells with this variant polymorphism have an increased sensitivity of about 20% to a broad range of cytotoxic agents. The DNA deficits caused by immunosuppressive drugs or the OGG1 polymorphism can be overcome by the delivery of DNA repair enzymes in liposomes. The data suggests that deficits in DNA repair, even if they are not as severe as in the case of XP, may contribute to increased rates of cancer, and that topical therapy with DNA repair enzymes may be a promising avenue for after-sun protection.

Cell Line↗

Gelatin-embedded cell-polymer constructs for histological cryosectioning.

Many tissue-engineering strategies involve the delivery of cells via porous polymer scaffolds. Obtaining histological sections of the emerging tissue is often necessary to analyze numerous characteristics of the microscopic environment. However, difficulties arise upon applying standard histological techniques to cell-seeded polymer scaffolds. This report describes a simple and reliable method for cryosectioning cell-polymer constructs embedded in gelatin. Solvent-soluble (PLGA) and insoluble (PGA) scaffolds were cultured in vitro with preosteoblasts, followed by histological processing with paraffin, OCT, or gelatin. Although paraffin-embedded PGA scaffolds withstood standard sectioning and rinsing steps, paraffin-embedded PLGA scaffolds were partially dissolved during the clearing step. OCT-embedded scaffolds produced sections that did not adhere well to slides, and most of the sample was lost during rinsing steps. In contrast, gelatin-embedded scaffolds exhibited adequate structural integrity during cryosectioning, adhered well to the slides, retained the actual polymer morphology, and exhibited compatibility with common stains.

Animals↗

Pathways modulating neural KCNQ/M (Kv7) potassium channels.

K(+) channels play a crucial role in regulating the excitability of neurons. Many K(+) channels are, in turn, regulated by neurotransmitters. One of the first neurotransmitter-regulated channels to be identified, some 25 years ago, was the M channel. This was categorized as such because its activity was inhibited through stimulation of muscarinic acetylcholine receptors. M channels are now known to be composed of subunits of the Kv7 (KCNQ) K(+) channel family. However, until recently, the link between the receptors and the channels has remained elusive. Here, we summarize recent developments that have begun to clarify this link and discuss their implications for physiology and medicine.

Animals↗

Calcineurin inhibitors decrease DNA repair and apoptosis in human keratinocytes following ultraviolet B irradiation.

The use of calcineurin inhibitors in solid organ transplantation results in an increased risk of skin cancer. We examined the effect of these drugs on DNA repair in normal human keratinocytes after ultraviolet B (UVB) irradiation. We found that both cyclosporine A (CsA) and ascomycin inhibited removal of cyclobutane pyrimidine dimers, and that they also inhibited UVB-induced apoptosis. We also observed that UVB induced nuclear localization of the transcription factor nuclear factor of activated T-cells (NFAT), and that this was blocked by CsA and ascomycin. These data suggest that the increased risk of skin cancer observed in organ-transplant patients may be as a result of not only systemic immune suppression but also the local inhibition of DNA repair and apoptosis in skin by calcineurin inhibitors. These findings may have implications for the use of topical calcineurin inhibitors in sun-exposed skin and eyes.

Active Transport, Cell Nucleus↗

Limb-loaded cycling program for locomotor intervention following stroke.

BACKGROUND AND PURPOSE: This case report describes implementation of a limb-loaded cycling (LLC) training program as a feasible exercise for people in early phases of locomotor training following stroke. CASE DESCRIPTION: Two individuals with early-stage poststroke hemiplegia participated in the LLC program as an adjunct to physical therapy intervention. Performance of LLC involved cycling while supporting progressive amounts of applied load and weight shifting from one lower extremity to the other lower extremity. The LLC was conducted daily during 2 to 3 weeks of inpatient rehabilitation. OUTCOMES: The LLC progressed with increases in weight bearing and force generation, as evidenced by larger amounts of limb loading during pedaling. The patients tolerated all loads without cardiorespiratory distress. DISCUSSION: Limb-loaded cycling can accommodate people with little force-generating capability or weight-bearing ability as they practice locomotor skills. Gains in locomotor ability may be aided by the addition of this exercise regimen to patients' daily physical therapy.

Aged↗

cAMP potentiates ATP-evoked calcium signaling in human parotid acinar cells.

In salivary acinar cells, intracellular calcium ([Ca(2+)](i)) signaling plays an important role in eliciting fluid secretion through the activation of Ca(2+)-activated ionic conductances. Ca(2+) and cAMP have synergistic effects on fluid secretion such that peak secretion is elicited following activation of both parasympathetic and sympathetic pathways. We have recently demonstrated that cAMP exerts effects on Ca(2+) release, through protein kinase A (PKA)-mediated phosphorylation of inositol 1,4,5-trisphosphate receptors (InsP(3)R) in mouse parotid acinar cells. To extend these findings, in the present study cross-talk between Ca(2+) signaling and cAMP pathways in human parotid acinar cells was investigated. In human parotid acinar cells, carbachol stimulation evoked increases in the [Ca(2+)](i) and the initial peak amplitude was enhanced following PKA activation, consistent with reports from mouse parotid. Stimulation with ATP also evoked an increase in [Ca(2+)](i). The ATP-evoked Ca(2+) elevation was largely dependent on extracellular Ca(2+), suggesting the involvement of the P2X family of purinergic receptors. Pharmacological elevation of cAMP resulted in a approximately 5-fold increase in the peak [Ca(2+)](i) change evoked by ATP stimulation. This enhanced [Ca(2+)](i) increase was not dependent on intracellular release from InsP(3)R or ryanodine receptors, suggesting a direct effect on P2XR. Reverse transcription-polymerase chain reaction and Western blot analysis confirmed the presence of P2X(4)R and P2X(7)R mRNA and protein in human parotid acinar cells. ATP-activated cation currents were studied using whole cell patch clamp techniques in HEK-293 cells, a null background for P2XR. Raising cAMP resulted in a approximately 4.5-fold enhancement of ATP-activated current in HEK-293 cells transfected with P2X(4)R DNA but had no effects on currents in cells expressing P2X(7)R. These data indicate that in human parotid acinar cells, in addition to modulation of Ca(2+) release, Ca(2+) influx through P2X(4)R may constitute a further locus for the synergistic effects of Ca(2+) and PKA activation.

Adenosine Triphosphate↗

Direction-dependent phasing of locomotor muscle activity is altered post-stroke.

A major contributor to impaired locomotion post-stroke is abnormal phasing of muscle activity. While inappropriate paretic muscle phasing adapts to changing body orientation, load, and speed, it remains unclear whether paretic muscle phasing adapts to reversal of locomotor direction. We examined muscle phasing in backward pedaling, a task that requires shifts in biarticular but not uniarticular muscle phasing relative to forward pedaling. We hypothesized that if paretic and neurologically intact muscle phasing adapt similarly, then paretic biarticular but not paretic uniarticular muscles would shift phasing in backward pedaling. Paretic and neurologically intact individuals pedaled forward and backward while recording electromyograms (EMGs) from vastus medialis (VM), soleus (SOL), rectus femoris (RF), semimembranosus (SM), and biceps femoris (BF). Changes in muscle phasing were assessed by comparing the probability of muscle activity in forward and backward pedaling throughout 18 pedaling cycles. Paretic uniarticular muscles (VM and SOL) showed phase-advanced activity in backward versus forward pedaling, whereas the corresponding neurologically intact muscles showed little to no phasing change. Paretic biarticular muscles were less likely than neurologically intact biarticular muscles to display phasing changes in backward pedaling. Paretic RF displayed no phase change during backward pedaling, and paretic BF displayed no consistent adaptation to backward pedaling. Paretic SM was the only muscle to display backward/forward phase changes that were similar to the neurologically intact group. We conclude that paretic uniarticular muscles are more susceptible and paretic biarticular muscles are less susceptible to direction-dependent phase shifts, consistent with altered sensory integration and impaired cortical control of locomotion.

Adaptation, Physiological↗

Serum macrophage inhibitory cytokine 1 as a marker of pancreatic and other periampullary cancers.

PURPOSE: Patients with pancreatic ductal adenocarcinoma usually present with advanced-stage disease and a dismal prognosis. One effective strategy likely to improve the morbidity and mortality from pancreatic cancer would be the identification of accurate, noninvasive diagnostic markers that would enable earlier diagnosis of symptomatic patients and earlier detection of cancer in asymptomatic individuals at high risk for developing pancreatic cancer. In this study, we evaluated serum macrophage inhibitory cytokine-1 (MIC-1) as a marker of pancreatic cancer. EXPERIMENTAL DESIGN: MIC-1 expression in primary pancreatic cancers, intraductal papillary mucinous neoplasms, and pancreatic cancer cell lines was determined using the National Center for Biotechnology Information serial analysis of gene expression database, oligonucleotide microarrays analysis, in situ hybridization, and immunohistochemistry. Serum MIC-1 levels were determined by ELISA in 80 patients with pancreatic adenocarcinomas, in 30 patients with ampullary and cholangiocellular carcinomas, in 42 patients with benign pancreatic tumors, in 76 patients with chronic pancreatitis, and in 97 healthy control subjects. The diagnostic performance of serum MIC-1 as a marker of pancreatic cancer was compared with that of serum CA19-9. RESULTS: Oligonucleotide microarray and serial analysis of gene expression data demonstrated that MIC-1 RNA levels were higher in primary pancreatic cancers, intraductal papillary mucinous neoplasms, and pancreatic cancer cell lines than in nonneoplastic pancreatic ductal epithelium. MIC-1 expression was localized to the malignant epithelium in pancreatic adenocarcinomas by in situ hybridization. MIC-1 protein was expressed in 14 of 16 primary pancreatic adenocarcinomas (88%) by immunohistochemistry and was also expressed in some pancreata affected by pancreatitis but not in normal pancreas. Serum MIC-1 levels were significantly higher in patients with pancreatic ductal adenocarcinoma (mean +/- SD, 2428 +/- 2324 pg/ml) and in patients with ampullary and cholangiocellular carcinomas (2123 +/- 2387 pg/ml) than in those with benign pancreatic neoplasms (940 +/- 469 pg/ml), chronic pancreatitis (1364 +/- 1236 pg/ml), or in healthy controls (546 +/- 262 pg/ml). An elevated serum MIC-1 (defined as 2 SD above the mean for healthy controls) performed as well as CA19-9 (area under the receiver operating characteristic curve, 0.81 and 0.77, respectively), and the combination of MIC-1 and CA19-9 significantly improved diagnostic accuracy (P < 0.05; area under the receiver operating characteristic curve, 0.87; sensitivity, 70%; specificity, 85%). CONCLUSION: Serum MIC-1 measurement can aid in the diagnosis of pancreatic adenocarcinoma.

Adenocarcinoma↗

Gating of the polycystin ion channel signaling complex in neurons and kidney cells.

Mutations in either polycystin-2 (PC2) or polycystin-1 (PC1) proteins cause severe, potentially lethal, kidney disorders and multiple extrarenal (including brain) disease phenotypes. PC2, a member of the transient receptor potential channel superfamily, and PC1, an orphan membrane receptor of largely unknown function, are thought to be part of a common signaling pathway. Here, we show that in rat sympathetic neurons and kidney cells, coassembly of full-length PC1 with PC2 forms a plasmalemmal ion channel signaling complex in which PC1 stimulation simultaneously activates PC2 ion channels and Gi/o-proteins. PC2 activation occurs through a structural rearrangement of PC1, independent of G-protein activation. Thus, PC1 acts as a prototypical membrane receptor that concordantly regulates PC2 channels and G-proteins, a bimodal mechanism that may account for the multifunctional roles of polycystin proteins in fundamental cellular processes of various cell types.

Animals↗

A DFT study of model complexes of zinc hydrolases and their inhibition by hydroxamic acids.

DFT calculations carried out on zinc acetate and zinc hydroxamates using the Hartree-Fock and B3LYP methods with the 6-311+G basis set give a series of stable pseudotetrahedral chelates (ZnL(2)) (L = OAc, FA, AA, NMeAA, GA, SA). Addition of a water molecule to these chelates gives the hydrates, ZnL(2).H(2)O, which in all cases are energetically more stable than the corresponding chelate. Hydrates formed from O,O coordinated hydroxamate species with a five-membered chelate ring contain water molecules occupying vacant coordination sites of the zinc atom. In contrast, those formed from zinc chelates with four-membered chelate rings contain a water molecule inserted into the chelate ring to give a six-membered ring in which one hydrogen of the water molecule is H-bonded to an oxygen atom of the zinc chelate with the water oxygen strongly bonded to the zinc. A slight lengthening of the H-bonded O-H bond suggests incipient hydroxide activation of water by zinc. In contrast, the O,O bonded hydroxamates do not incorporate water into the chelate ring nor activate the water in accordance with the ability of hydroxamic acids to inhibit zinc containing metalloenzymes.

Chelating Agents↗

Serum concentrations of macrophage inhibitory cytokine 1 (MIC 1) as a predictor of miscarriage.

Macrophage inhibitory cytokine 1 (MIC 1) is thought to have immunomodulatory actions favouring fetal viability. We measured serum concentrations of MIC 1 in asymptomatic women at 6-13 weeks' gestation who subsequently miscarried or who had already miscarried. MIC 1 concentrations in the miscarriage cohort (n=100), were a third of those who had ongoing pregnancies (n=197). Multiples of the median for miscarriage was 0.32 (95% CI 0.23-0.32) versus 1.00 (0.93-1.06) for ongoing pregnancies; p<0.0001. Concentrations were just as low 3 weeks before diagnosis as on the day of diagnosis. That MIC 1 serum concentrations seem to be low weeks before miscarriage suggests possible predictive and causative roles, as well as therapeutic potential.

Abortion, Spontaneous↗