Mild PE Research Articles

Evaluation of Glutathione Peroxidase 4 role in Preeclampsia.

Preeclampsia (PE) is a pregnancy-specific syndrome that may be lifethreatening to pregnancies and fetus. Glutathione Peroxidase 4 (GPx4) is a powerful antioxidant enzyme that can provide protection from oxidative stress damage which plays a pivotal role in the pathology of PE. Therefore, this study aims to investigate the association between Gpx4 polymorphisms and the susceptibility to PE in Chinese Han women. TaqMan allelic discrimination real-time PCR was used to perform the genotyping of rs713041 and rs4807542 in 1008 PE patients and 1386 normotensive pregnancies. Obviously statistical difference of genotypic and allelic frequencies were found of rs713041 in GPx4 between PE patients and controls and the C allele has the higher risk for pathogenesis of PE (χ2 = 12.292, P = 0.002 by genotype; χ2 = 11.035, P = 0.001, OR = 1.216, 95% CI 1.084–1.365 by allele). Additionally, when subdividing these samples into CC + CT and TT groups, we found a significant difference between the two groups (χ2 = 11.241, P = 0.001, OR = 1.417, 95% CI 1.155–1.738). Furthermore, the genotype of rs713041 was found to be associated with the mild, severe and early-onset PE. Our results suggest that rs713041 in GPx4 may play a key role in the pathogenesis of PE.

Prediction of cesarean section risk in women with gestational hypertension or mild preeclampsia at term

ObjectiveIn a recent randomized controlled trial we found that induction of labor in women with gestational hypertension (GH) or mild (preeclampsia) PE at term prevented high risk situations without increasing the cesarean section (CS) rate. We aimed to assess the predictability of the risk of CS. Study designWe used multivariable logistic regression analysis to identify predictive factors. Two models were created, one including antepartum and one including antepartum and intrapartum variables. The predictive capacity was assessed with ROC analysis and calibration. Results126 (17%) of the 756 women delivered by CS. In multivariable analysis parity (OR 5.4), ethnicity (OR 2.4), previous miscarriage (OR 1.7), creatinine (OR 1.02), proteinuria (OR 2.4), cervical length (OR 1.02), engagement (OR 0.5) and dilatation (OR 0.7) were independent antepartum predictors. Intrapartum variables were parity (OR 3.6), ethnicity (OR 1.9), previous miscarriage (OR 1.5), gestational age at delivery (OR 1.2), antibiotic use (OR 8.0), disease progression (OR 2.4), uric acid (OR 1.4), proteinuria (OR 3.50) and dilatation (OR 0.76). Both models showed good discrimination (AUC 0.74 and 0.80) but calibration was moderate (Hosmer–Lemeshow P-value 0.42 and 0.70). ConclusionIn women with GH or mild PE at term, the risk of CS can be predicted.

166-POS

Objectives To determine if urine MMP levels were increased in women with PE. Urine levels of kidney injury biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) were also determined. Methods Urine specimen were collected from 86 pregnant women (28 normotensive, 15 complicated with chronic hypertension, 11 mild PE, and 32 severe PE) at the time of recruitment before delivery and 6–8 weeks postpartum. Urine concentrations of MMP2, MMP9, metallopeptidase inhibitor 2 (TIMP2), NGAL, and KIM-1 were measured by ELISA. All samples were assayed in duplicate. Urine creatinine concentration was also determined. Data are expressed as mean ± SE ng/mg creatinine and analyzed by ANOVA with Newman–Keuls as the post hoc test. A probability level less than 0.05 was considered statistically different. Results Urine concentrations of MMP2, MMP9, NGAL, and KIM-1 were significantly higher in women with severe PE than in normotensive pregnancies, MMP2: 3.033±0.612 vs. 1.411 ± 0.219 ng/mg creatinine, p p p p Conclusions NGAL and KIM-1 are biomarkers used to evaluate risk of renal damage in kidney diseases. Podocyte shedding is significantly increased in severe PE. The findings of increased urine levels of MMP2 and MMP9 associated with increased NGAL and KIM-1 in women with severe PE suggest that increased renal matrix metallopeptidase production may contribute to the glomerular barrier injury and podocyte shedding in PE. NGAL and KIM-1 could also be used as biomarkers to evaluate kidney dysfunction in PE. Disclosures Y. Wang: None. Y. Gu: None. S. Loyd: None. L.J. Groome: None.

Inconformity of CXCL3 Plasma Level and Placenta Expression in Preeclampsia and Its Effect on Trophoblast Viability and Invasion

As a member of the chemokine family, CXCL3 was previously known to participate in many pathophysiological events. However, whether CXCL3 stimulates trophoblast invasion as a key process of preeclampsia pathogenesis remains largely unknown. Therefore, the aim of this study was to investigate this hypothesis and determine the effect of CXCL3 on the first trimester trophoblast. Seventy gravidas were included in this study. ELISA was used to detect CXCL3 plasma levels on preeclampsia and normal pregnant groups. CXCL3 protein and mRNA levels were detected via Western blot and real-time quantitative PCR analysis after immunolocalized in human placenta. Moreover, the CXCL3 function in HTR-8/Svneo was analyzed via WST-1 assay, flow cytometry and invasion test. The plasma CXCL3 level in preeclampsia was significantly higher than that in normal pregnancy. CXCL3 expression was observed in the cytoplasm of placental trophoblasts and vascular endothelium in all groups without significant difference between maternal and fetal sides. In addition, placenta CXCL3 expression in severe preeclampsia was significantly lower than those in normal and mild PE groups. Moreover, exogenous CXCL3 can promote the proliferation and invasion of HTR-8/Svneo; however, its effect on apoptosis remains unclear. In summary, a significant abnormality of plasma CXCL3 level and placental CXCL3 expression was discovered in severe preeclampsia; CXCL3 had a function in trophoblast invasion, which indicated its participation in shallow implantation. Therefore CXCL3 might be involved in severe preeclampsia pathogenesis.

Expression of lipoxin A4, TNFα and IL-1β in maternal peripheral blood, umbilical cord blood and placenta, and their significance in pre-eclampsia

Objective: The purpose of this study was to investigate the expression of lipoxin A4, TNFα and IL-1β in maternal peripheral blood, umbilical cord blood and placenta, and to assess their significance in pre-eclampsia. Methods: Ninty pregnant women were divided into three groups: a mild PE group (n = 30), a severe PE group (n = 30) and a control group (n = 30). We measured serum levels of lipoxin A4, TNFα and IL-1β using ELISA. Expression levels of lipoxin receptor (FPR2/ALX) mRNA were compared using quantitative RT-PCR. Results: Mean circulating levels of lipoxin A4, TNFα and IL-1β in the PE groups were significantly increased compared with matched women in the control group. The ratios of lipoxin A4/TNFα and of lipoxin A4/IL-1β in the PE groups were significantly decreased compared with matched women in the control group. No lipoxin A4 was detected in umbilical cord blood. There was a significant increase in FPR2/ALX mRNA expression in placenta obtained from the PE groups. Conclusions: The level of lipoxin A4 in maternal peripheral blood may correlate with the expression of FPR2/ALX in placenta. Lipoxin A4 increased to a lesser degree than either TNFα or IL-1β with progression of PE. This may be one of the reasons why oxidative stress and endothelial dysfunction in severe preeclamptic patients are much more serious that in cases of less severe preeclampsia. Moreover, lipoxin A4 does not have any effect on the fetus through the placenta. We conclude that supplementing with lipoxin A4 to ensure adequate levels may be a novel method for the treatment of pre-eclampsia without any effects on the fetus.

The Interval Between Pregnancies as A Risk Factor for Mild and Severe Forms of Preeclampsia

We studied 300 normotensive and 100 PE pregnancies divided into two subgroups: mild (�� = 67) and severe (�� = 33) PE. This research has included only single pregnancies and the following parameters: maternal age, parity, previous pregnancy history and interval between pregnancies. The study is based on 400 pregnancies with a mean age of 27.65±5.04 years. The significant difference in the frequency of categories and age groups was tested with a method of multivariate analysis for proportion. The difference was not statistically significant �� > 0.05, which clearly shows that the groups are a priori similar and comparable. Our study shows that PE is most commonly developed in primiparas (�� < 0.05). The difference was at the level �� < 0.001. Among women with no history of PE, the median interbirth interval was 4.24 years between the previous and actual pregnancy. Among women with mild PE the median interbirth interval was 5.96 and in group with severe PE was 8.08 years. Multiparous women who are pregnant 5, especially 10 years or more after their previous pregnancy are as likely to have preeclampsia as nulliparous women.

KE and EE Genotypes of ICAM-1 Gene K469E Polymorphism Is Associated with Severe Preeclampsia

Background. Preeclampsia (PE) is one of the most important complications of pregnancy that is associated with significant mortality and morbidity in mother and fetus. Since the etiologic factors in its development are still unclear, we aimed to examine the intercellular adhesion molecule-1 (ICAM-1) gene K469E polymorphism in preeclamptic and control healthy women. Materials and Methods. Genetic polymorphism was analyzed in 192 PE and 186 healthy control women. PCR-RFLP method was used to identify K469E polymorphism. Results. The frequency of KK, KE, and EE genotypes of ICAM-1 gene was not different between PE patients and healthy pregnant women. Whereas, the frequency of KE and EE genotypes was significantly higher in severe PE than mild PE women and control group, and the risk of severe PE was 2.4-fold higher in subjects with KE genotype (OR, 2.4 [95% CI, 1 to 5.9]; P = 0.03) and 3.3-fold higher in subjects with EE genotype (OR, 3.3 [95% CI, 1.2 to 9]; P = 0.015) compared to individuals with KK genotype. Conclusion. We concluded that KE and EE genotypes of K469E polymorphism could increase risk of severe PE.

PP047. Outpatient management of pregnancy complicated by mild hypertensive disorders

Antenatal day care units have been experienced as an alternative to inpatient care for women with pregnancy complications including hypertensive disorders. To assess the outcomes of outpatient management in women with gestational hypertension and mild preeclampsia and compare them to inpatient management. Perinatal records of 294 patients (OUT group) attending the obstetric outpatient clinic were reviewed and compared with records of 398 women (IN group) attending the obstetric unit of the same tertiary referral center. The patients were divided as: GH, gestational hypertension (OUT: 194; IN: 244), GH with Intrauterine Growth Restriction (OUT: 52; IN: 78) and PE, mild preeclampsia (OUT: 48; IN: 76). The groups were comparable for age, parity, body mass index and gestational age at enrollment. When compared with patients treated in hospital, GH OUT women showed a higher gestational age at delivery (38±1.7 vs 35.5±2.3 weeks; p<0.001), longer time to delivery (62.0±4.8 vs 31.3±5.4days; p<0.001), higher birthweight (3251±389 vs 2271±759.1g; p<0.001), and a lower admission to neonatal intensive care unit (21.3% vs 0%; p<0.001) (hospitalization rate: 25%). Similarly, Mild PE women treated as out patient showed later gestational age at delivery (37±1.2 vs 34.4±1.7weeks), longer time to delivery (55.4±6.9 vs 35.3±4.5days), higher birthweight (3168±363 vs 2196±685.17g), and a lower admission to NICU (15.6% vs 35.5%) (hospitalization rate: 55.6%), than the inpatient controls. In the gestational hypertension with IUGR no significant differences were observed between out- and in-patient management. Women attending day care units have better or comparable perinatal outcomes than inpatients. Ambulatory management at a day-care unit is an option for monitoring and following up women with mild gestational hypertension or preeclampsia remote from term. Hospitalization remains an absolute indication if worsening of preeclampsia is diagnosed.

CAMBIOS EN LA EXPRESIÓN DE LOS MARCADORES DE DISFUNCIÓN ENDOTELIAL PAL-1/PAI-2 EN PREECLAMPSIA LEVE Y SEVERA, Y EN GESTANTES NORMOTENSAS SANAS

Objective: To determine levels of Plasminogen Activator Inhibitor type 1 and 2 (PAl-1 y PAI-2) , and Placental Growth Factor (PlGF) in mild and severe PE as markers of endothelial disfunction and angiogenesis in mild and severe preeclampia, respectively. Methods: A cohort study performed at Hospital Clinico de la Universidad de Chile during between june 2009 and december.2012. Population was consisted of pregnants registered during the period of study, and were divided in three groups as follow: controls (n=18), severe PE (n=23) and mild PE (n=9). Blood samples were obtained from each patient to determine, by immunoassay techniques, the levels of PIGF and PAI-1/PAI-2. ANOVA-Bonferroni test was used in the statistical analysis used with a significance p <0.05. Results: We observed lower levels of PlGF and over PAI-1/PAI-2 in PE versus controls. Women with severe PE showed higher levels of relationship PAI-1/PAI-2 that women with mild PE (p <0.05). There was no sig nificant difference for PlGF between mild and severe PE. Conclusions: The severity of preeclampsia is reflected in the magnitude of the changes in biomarkers of endothelial dysfunction and angiogenesis. The measurement of PlGF and PAI-1/PAI-2 relationship in early pregnancy could have a prognostic value in the development of PE.

P10. Placental expression of haemostatic and angiogenic markers in preeclampsia

cantly higher than in late onset PE (497 ± 81 vs. 13 ± 4, p < 0,001 and 131 ± 15 vs. 29 ± 5, p < 0.001; p for early vs. late PE <0.001). Again ROC curves and their AUC showed best performance for the sFlt1/PlGF ratio, being 98.6% (vs. 97.6% for sFlt1 and 97.4% for PlGF) in early onset PE vs. controls and 90.8% (vs. 82.1% for sFlt1 and 88.4% for PlGF) in late onset PE. Patients with superimposed, mild or severe PE and HELLP each showed higher ratios than controls (202 ± 110; 137 ± 27; 497 ± 91 and 254 ± 72 vs. 16 ± 2, each p < 0.001); in calculated ROC curves, their AUC were 93.6%, 94.8%, 99.4% and 98.6%, respectively. Whereas sFlt1/PlGF values compared to controls were significantly higher in patients with PIH and GP, no significant difference was observed in patients with cHT (PIH 65 ± 18 vs. 16 ± 2, p < 0.001; GP 62 ± 25 vs. 16 ± 2, p = 0.01 and cHT 13 ± 8 vs. 16 ± 2, p = 0.6). Ratio values of patients with each PIH and GP were significantly lower than in patients with mild PE (p < 0.007), severe PE (p < 0.001) and HELLP (p < 0.003). Compared to patients with superimposed PE a significant difference was observed only vs. GP (p = 0.015) whereas vs. PIH no significant difference was observed (p = 0.178). Conclusion: The automated measurement of sFlt1/PlGF is a reliable tool to discriminate between different types of pregnancy-related hypertensive disorders, particularly in early onset PE, severe PE and HELLP, being the most severe variations of PE. Thus, sFlt1/PlGF gives additional valuable information and can be used as an aid in diagnosis and therefore adapt clinical management. First Author < 35 years: Yes.

Premature and delayed ejaculation: two ends of a single continuum influenced by hormonal milieu

Although it is well established that all the aspects of male reproduction are hormonally regulated, the endocrine control of the ejaculatory reflex is still not completely clarified. Sex steroids, thyroid and pituitary hormones (oxytocin and prolactin) have been proposed to control the ejaculatory process at various levels; however, only a few reports are currently available. The aim of this study was to evaluate the contribution of testosterone, thyrotropin (TSH) and prolactin (PRL) in the pathogenesis of ejaculatory dysfunction in a large series of subjects consulting for sexual dysfunction. Among the 2652 patients studied, 674 (25.2%) and 194 (7.3%) reported premature and delayed ejaculation (PE and DE), respectively. Categorizing ejaculatory difficulties on an eight-point scale starting from severe PE and ending with anejaculation (0 = severe PE, 1 = moderate PE, 2 = mild PE, 3 = no difficulties, 4 = mild DE, 5 = moderate DE, 6 = severe DE and 7 = anejaculation), PRL as well as TSH levels progressively increased from patients with severe PE towards those with anejaculation. Conversely, the opposite was observed for testosterone levels. All of these associations were confirmed after adjustment for age (adjusted r = 0.050, 0.053 and -0.038 for PRL, TSH and testosterone, respectively; all p < 0.05). When all hormonal parameters were introduced in the same regression model, adjusting for age, ΣMHQ (an index of general psychopathology) and use of selective serotonin reuptake inhibitor antidepressants, they were independently associated with ejaculatory problems (adjusted r = 0.056, 0.047 and -0.059 for PRL, TSH and testosterone, respectively; all p < 0.05). This study indicates endocrine system is involved in the control of ejaculatory function and that PRL, TSH and testosterone play an independent role.

Complement component C4A and apolipoprotein A-I in plasmas as biomarkers of the severe, early-onset preeclampsia

Preeclampsia is a common pregnancy complication that is associated with maternal perinatal morbidity and mortality. Because of its early onset (before 34 weeks) and the potential for serious outcomes, severe, early-onset preeclampsia (sePE) should be regarded as a different form of preeclampsia. It is an important cause of preterm birth and fetal growth restriction and adverse maternal and neonatal outcomes. As there is no diagnostic test yet available for this disease, we used a proteomic approach to identify novel plasma biomarkers for developing severe, early-onset preeclampsia. We conducted case-control studies comparing nulliparous women with severe preeclampsia requiring delivery prior to 34 weeks of gestation with healthy nulliparous women matched by gestational age at sampling. Plasma was depleted of albumin and IgG and analyzed by two-dimensional gel electrophoresis (2DE). Seven specific plasma proteins for early-onset preeclampsia were detected by mass spectrometry had statistically significant expression differences when compared to controls. The expression of complement component C4A and apolipoprotein A-I were validated by immunoblotting. The complement component C4A in the plasmas of sePE women is lower than the severe, late-onset PE (slPE) women [mean ± SD; 3.05 ± 0.14 times reference level (normal/sePE) in sePE women vs. 2.73 ± 0.10 times reference level (normal/slPE) in slPE women, P < 0.05]. Apolipoprotein A-I is higher in sePE women than slPE women [mean ± SD; 1.58 ± 0.14 times reference level (sePE/normal) in sePE women vs. 1.04 ± 0.16 times reference level (slPE/normal) in slPE women, P < 0.05]. Furthermore, C4A can accurately distinguish severe PE (sePE and slPE) from mild PE (mePE and mlPE) and was proved by the results of ELISA. Further studies have been done to determine the relation between PE and hypoxia. JAR cells were cultured under hypoxia for 72 h. Total cellular proteins were gathered and lysed. Lower C4A and higher apolipoprotein A-I had been observed in JAR of hypoxia conditions than normoxia conditions through western blotting. The result proved that PE is correlated with hypoxia. In summary, C4A and apolipoprotein A-I are able to function as markers to distinguish ePE women from lPE women, and severe PE from mild PE, or perhaps even as disease predictors that might become relevant for diagnostics.

Utility of Single-slice High-resolution CT in Upper Lung Field Combined with Low-dose Spiral CT for Lung-cancer Screening in the Detection of Emphysema

The present study was undertaken to evaluate the utility of low-dose spiral CT scanning, combined with single-slice high-resolution CT (HRCT), in the detection of pulmonary emphysema on CT (CTPE) together with screening for lung cancer. For 657 individuals who visited for screening of lung cancer, single-slice HRCT of the upper lung field was added on conventional low-dose spiral CT scanning in order to detect low attenuation area (LAA) visually. The individuals were classified into four groups according to the visual extent of LAA in bilateral upper lung fields: no LAA, subtle PE (0%<LAA%< or =5%), mild PE (5%<LAA%< or =25%) and moderate to severe PE (LAA%>25%), and compared spirometry among the four groups. LAA was detected in 23.3% of all subjects (subtle PE in 12.2%, mild PE in 9.9% and moderate to severe PE in 1.2%) by adding one HRCT slice whereas only in 6.4 % LAA was detected by conventional low-dose helical CT scanning at 10 mm slice alone. The airway obstruction (FEV1/FVC<70%) was observed only in 1.07%. The severity of emphysema was associated with older age, prevalence of having smoking history and Brinkman index. As the severity of emphysema, the FEV1/FVC, MMEF, and V25/HT showed lower values. It is suggested that single-slice HRCT of the upper lung field combined with conventional low-dose spiral CT scanning for screening of lung cancer may also be useful for the detection of LAA, which may promote smoking cessation.

1173 Determinants of left atrial dilation in patients with hypertrophic cardiomyopathy

s S209 Eur J Echocardiography Abstracts Supplement, December 2006 performed. Fourteen pts had a follow-up echocardiogram; totally we collected data of 300 echocardiograms. The PE was classified as very mild (mean distance between the pericardial layers 5 and 2 cm). Results: The pts were 228 males, 57 females, 1 transexual (male to female), aged 22 to 66 yrs (mean 40). Among the 286, 122 had AIDS (55 non-Hodgkin lymphoma, 16 Kaposi sarcoma, 10 carcinomas, 41 systemic infections). PE was detected in 31 pts (10.8%) at first examination and in two more pts at follow-up: totally 33 pts (11.5%) had PE, that was very mild in 20, mild in 11, large (requiring pericardial drainage) in 2 pts. PE was more frequent in pts with AIDS than in those without (17.2% vs 7.3%, p<0.05). Among AIDS pts, it was more frequent in those with lymphoma than in those without it (27.2% vs 8.9%, p<0.05). Two pts with myocarditis had mild PE. Conclusions: Pericardial effusion is rare in our HIV+ population, and seldom requires therapeutic interventions. It is more frequent in AIDS pts and, among them, in pts with lymphoma. Routine echocardiographic screening is not recommended in HIV+ pts, unless there is a clinical suspicion of heart disease.

Nature and progression of pericardial effusion in patients with a first myocardial infarction: Relationship to age and free wall rupture

Background Left ventricular free wall rupture (FWR) usually develops within the first days of acute myocardial infarction (AMI) without warning, but it is uncertain whether a mild pericardial effusion might herald this complication. Methods A 2-dimensional echocardiogram (2DE) was performed in patients with first AMI with (1149) or without (324) ST-segment elevation within 2 days. A second 2DE was performed 2 to 4 days later in 300 patients, 100 with and 200 without an initial mild PE (3-9 mm), and in those with initial moderate-severe PE (≥10 mm) (MSPE) or who developed hypotension or died. Results The first 2DE showed mild PE in 177 patients and MSPE in 51 patients, whereas a late (>2 days) MSPE occurred in 27 with a second routine 2DE, 15 (15%) with and 12 (6%) without initial mild PE (P =.01). Fourteen additional patients, 5 of 77 (6%) with and 9 of 1045 (1%) without initial PE, presented with hypotension and late MSPE (P <.002). Of 92 patients with MSPE, 90 had ST-segment elevation (98%), 60 had tamponade (65%), and 38 died of FWR or were operated on (41%). Results of pericardiocentesis performed in 64 patients were positive in 58, with hemopericardium in 57 (98%). Multivariant analysis showed mild PE on first 2DE and age of >60 years as the only independent predictors of late MSPE or late tamponade. Conclusions Mild PE within the first 2 days in patients aged >60 years with a first ST-segment elevation AMI is associated with an increased risk of late MSPE. Moreover, in this setting MSPE is most frequently associated with hemopericardium, and two thirds of these patients may develop tamponade/FWR. (Am Heart J 2002;144:251-8.)

PRORENIN CONCENTRATION IN THE HYPERTENSIVE DISORDERS IN PREGNANCY

Objective: To evaluate the plasma prorenin levels during the three trimesters of normal pregnancy, their prognostic value, and their correlation with hypertensive disorders of pregnancy.Design: A prospective study in which plasma prorenin and renin levels were measured in 55 healthy pregnant women and 66 who developed gestational hypertension or preeclampsia. The patients were classified as mild preeclampsia (mild PE), severe preeclampsia (severe PE), chronic hypertension and superimposed preeclampsia upon chronic hypertension (superimposed PE).Method: Venous blood samples were collected in the first, second and third trimesters and during delivery or cesarean. Plasma renin concentration (PRC) was measured by radioinmmunoassay before and after incubation with trypsin solution. The difference gave plasma prorenin concentration (PProRC).Results: PRC and PProRC were significantly higher in pregnant women compared with healthy non-pregnant. PRC was significantly increased in the first trimester in the chronic hypertension group and a lower value was found in the first trimester in the superimposed PE compared with those in healthy pregnant women. No differences in other groups were found. PProRC showed a significant lower value in the first and third trimesters in the severe PE group. In the superimposed PE a low value of PProRC similar to those of non-pregnant women was found.Conclusions: The results show that the different types of hypertension in pregnancy have different profiles of PProRC and PRC in relation to development of preeclampsia. The absence of increase of PProRC in the first trimester of superimposed PE may have a prognostic value.

Real Time Video Techniques in the Analysis of Blown Film Instability

Abstract This paper describes a device which was developed to measure the degree of instability during blown film processing. Two types of data analysis are developed which can be used to analyze the instability data and the relative merits of each are discussed. The paper also describes how the device was used to measure the effect of adding two stabilizers (2 MI LDPE and 0.25 MI LDPE) at different concentrations to a 1 MI LLDPE during blown film processing. The process stability improved with higher concentrations of either LDPE with the 0.25 MI LDPE having the stronger effect. These results are consistent with the belief that long chain branching in polyethylenes plays a major role in stabilizing the blown film processing of polyethylenes.