Individuals with gluteal tendon repair display similar hip biomechanics to those of a healthy cohort during a sit-to-stand task.

BACKGROUND: Gluteal-tendon repair (GTR) is reported to be effective for relieving pain and improving clinical function in patients with gluteal-tendon tears. The sit-to-stand (STS) task is an important activity of daily living and is often used to assess functional capacity in clinical populations. Understanding if and how STS performance is altered in individuals with gluteal tendon repair may be an effective marker of GTR outcomes as well as a possible therapeutic target for post-operative rehabilitation. RESEARCH QUESTION: Do biomechanical parameters during STS differ between age- and sex-matched participants with and without gluteal-tendon repair? METHODS: 27 participants with a GTR and 29 healthy participants performed the STS task. Data were acquired using the three-dimensional motion capture system and forceplates. Outcomes of interest were task duration, rate of force development, trunk, pelvis, and hip joint angles, moments and powers. Differences were assessed using Generalised linear multivariate models and statistical parametric mapping. RESULTS: GTR patients performed the STS movement significantly slower (1.4+/- 0.40 s) compared to controls (1.1+/ -0.2 s) with a significantly lower rate of force development (35.1+/- 5.7 N/kg/ms vs 30.3+/- 8.5 N/kg/ms). There were no group differences for hip, pelvis, or trunk angle over the movement cycle or for maximal or minimal values. Furthermore, there were no significant differences detected in hip joint kinetics. However, there appeared to be substantial between-subject variability indicating different patient-specific movements patterns. SIGNIFICANCE: Individuals with a GTR performed the STS task about 20 % slower than healthy controls with a lower rate of force development. The individual variations indicate that participants likely employed different movement strategies to achieve STS. While the lack of differences between groups could suggest that GTR helps restore function and corrects the proposed underlying aetiology, it is possible that the STS task was not sufficiently challenging to discriminate between groups.

People after gluteal tendon repair have gait characteristics which are similar to those of a healthy cohort.

BACKGROUND: Gluteal-tendon repair is reported to be effective for relieving pain and improving function in patients with gluteal-tendon tears. However, post-operative three-dimensional gait analysis has never been conducted in gluteal-tendon repair patients. Thus, our primary aim was to investigate how biomechanical gait parameters differ between age- and sex-matched participants with and without gluteal-tendon repair. METHODS: Vicon motion analysis technology was used to measure gait characteristics of 25 gluteal-tendon repair participants and 29 matched healthy comparison group participants. A generalised linear multivariate model was used to compare external hip-adduction moment, range of movement in hip adduction and internal rotation, pelvic obliquity, trunk lean, stride length and velocity of both cohorts throughout stance. FINDINGS: There were no differences between the groups in external hip adduction moment, pelvic obliquity and range of movement in hip adduction and internal rotation. Gluteal-tendon repair participants had a shorter stride length (P = 0.031) and reduced walking velocity (P = 0.015). Ipsilateral trunk lean was reduced in gluteal-tendon repair participants at the first-peak external hip-adduction moment (P = 0.016), mid-stance minimum external hip-adduction moment (P = 0.029) and second-peak external hip-adduction moment (P = 0.006). INTERPRETATION: There were no differences between the gluteal-tendon repair and comparison groups for external hip-adduction moment and pelvic obliquity. This suggests that gluteal-tendon repair may restore hip control in stance. Slower walking speed, reduced stride length and decreased ipsilateral trunk lean may reflect persistence of pre-operatively developed gait adaptations. Future studies of gait biomechanics before and after gluteal-tendon repair would be needed to substantiate this theory.

A GABAergic Maf-expressing interneuron subset regulates the speed of locomotion in Drosophila.

Interneurons (INs) coordinate motoneuron activity to generate appropriate patterns of muscle contractions, providing animals with the ability to adjust their body posture and to move over a range of speeds. In Drosophila larvae several IN subtypes have been morphologically described and their function well documented. However, the general lack of molecular characterization of those INs prevents the identification of evolutionary counterparts in other animals, limiting our understanding of the principles underlying neuronal circuit organization and function. Here we characterize a restricted subset of neurons in the nerve cord expressing the Maf transcription factor Traffic Jam (TJ). We found that TJ+ neurons are highly diverse and selective activation of these different subtypes disrupts larval body posture and induces specific locomotor behaviors. Finally, we show that a small subset of TJ+ GABAergic INs, singled out by the expression of a unique transcription factors code, controls larval crawling speed.

Situational awareness within objective structured clinical examination stations in undergraduate medical training - a literature search.

BACKGROUND: Medical students may not be able to identify the essential elements of situational awareness (SA) necessary for clinical reasoning. Recent studies suggest that students have little insight into cognitive processing and SA in clinical scenarios. Objective Structured Clinical Examinations (OSCEs) could be used to assess certain elements of situational awareness. The purpose of this paper is to review the literature with a view to identifying whether levels of SA based on Endsley's model can be assessed utilising OSCEs during undergraduate medical training. METHODS: A systematic search was performed pertaining to SA and OSCEs, to identify studies published between January 1975 (first paper describing an OSCE) and February 2017, in peer reviewed international journals published in English. PUBMED, EMBASE, PsycINFO Ovid and SCOPUS were searched for papers that described the assessment of SA using OSCEs among undergraduate medical students. Key search terms included "objective structured clinical examination", "objective structured clinical assessment" or "OSCE" and "non-technical skills", "sense-making", "clinical reasoning", "perception", "comprehension", "projection", "situation awareness", "situational awareness" and "situation assessment". Boolean operators (AND, OR) were used as conjunctions to narrow the search strategy, resulting in the limitation of papers relevant to the research interest. Areas of interest were elements of SA that can be assessed by these examinations. RESULTS: The initial search of the literature retrieved 1127 publications. Upon removal of duplicates and papers relating to nursing, paramedical disciplines, pharmacy and veterinary education by title, abstract or full text, 11 articles were eligible for inclusion as related to the assessment of elements of SA in undergraduate medical students. DISCUSSION: Review of the literature suggests that whole-task OSCEs enable the evaluation of SA associated with clinical reasoning skills. If they address the levels of SA, these OSCEs can provide supportive feedback and strengthen educational measures associated with higher diagnostic accuracy and reasoning abilities. CONCLUSION: Based on the findings, the early exposure of medical students to SA is recommended, utilising OSCEs to evaluate and facilitate SA in dynamic environments.

How people who self-harm negotiate the inpatient environment: the mental healthcare workers perspective.

WHAT IS KNOWN ABOUT THE SUBJECT?: Self-harm plays a function, commonly in the form of distress management. There has been little focussed exploration of how individuals who use self-harm to manage distress cope when prevented from self-harm in an inpatient environment and how staff respond to this issue. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE: This paper uses the experiences of mental health staff to add to the existing knowledge that self-harm has a functional role and supports the notion that interventions for self-harm should focus on the origins of distress. It describes the potential consequences that focussing on prevention of self-harm as opposed to actually managing distress may have on service-users, how staff attempt to manage these consequences and factors that may impact on staff interventions to prevent further distress/harm. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The findings suggest that mental healthcare staff should aim to understand the function of self-harm, use this understanding to develop an individualized care plan with the aim of managing distress and identify barriers to the effectiveness of the interventions so they can be worked around. ABSTRACT: Introduction Literature describes self-harm as functional and meaningful. This creates difficulties for service-users detained in an inpatient environment where self-harm is prevented. Aim Mental healthcare staff were interviewed to build on existing evidence of issues with the prevention approach and explore, from a staff perspective, how self-harm prevention impacts on service-users, how they manage distress and how this impacts on staff and their approach to care. Methods Qualitative methods were used to allow unexpected themes to arise. Ten semi-structured interviews were carried out with mental healthcare staff and thematically analysed. Findings and discussion The findings provide new evidence on the benefits and limitations of the inpatient environment for individuals who self-harm. Findings indicate that being unable to self-harm can lead to a continuation of distress and subsequent potentially harmful attempts to manage distress. Staff described experiencing a struggle for control in preventing self-harm, leading to increasingly harmful methods of self-harm. Alternatively some staff were able to support service-users with distress management. We discuss factors influencing which of these 'paths' service-users followed. Implications Considerations for care planning including understanding self-harm, using individualized care planning and attending to barriers are outlined with the ultimate aim of reducing distress and the impact of prevention of self-harm.

Reliability and validity of OSCE checklists used to assess the communication skills of undergraduate medical students: A systematic review.

OBJECTIVES: To explore inter-rater agreement between reviewers comparing reliability and validity of checklist forms that claim to assess the communication skills of undergraduate medical students in Objective Structured Clinical Examinations (OSCEs). METHODS: Papers explaining rubrics of OSCE checklist forms were identified from Pubmed, Embase, PsycINFO, and the ProQuest Education Databases up to 2013. Included were those studies that report empirical validity or reliability values for the communication skills assessment checklists used. Excluded were those papers that did not report reliability or validity. RESULTS: Papers focusing on generic communication skills, history taking, physician-patient communication, interviewing, negotiating treatment, information giving, empathy and 18 other domains (ICC -0.12-1) were identified. Regarding the validity and reliability of the communication skills checklists, agreement between reviewers was 0.45. CONCLUSIONS: Heterogeneity in the rubrics used in the assessment of communication skills and a lack of agreement between reviewers makes comparison of student competences within and across institutions difficult. PRACTICE IMPLICATIONS: Consideration should be afforded to the adoption of a standardized measurement instrument to assess communication skills in undergraduate medical education. Future research will focus upon evaluating the potential impact of adoption of a standardized measurement instrument.

Back to the future: An online OSCE Management Information System for nursing OSCEs.

BACKGROUND: The Objective Structured Clinical Examination (OSCE) is an established tool in the repertoire of clinical assessment methods in nurse education. The use of OSCEs facilitates the assessment of psychomotor skills as well as knowledge and attitudes. Identified benefits of OSCE assessment include development of students' confidence in their clinical skills and preparation for clinical practice. However, a number of challenges exist with the traditional paper methodology, including documentation errors and inadequate student feedback. OBJECTIVES: To explore electronic OSCE delivery and evaluate the benefits of using an electronic OSCE management system. To explore assessors' perceptions of and attitudes to the computer based package. DESIGN: This study was conducted using electronic software in the management of a four station OSCE assessment with a cohort of first year undergraduate nursing students delivered over two consecutive years (n=203) in one higher education institution in Ireland. A quantitative descriptive survey methodology was used to obtain the views of the assessors on the process and outcome of using the software. METHODS: OSCE documentation was converted to electronic format. Assessors were trained in the use of the OSCE management software package and laptops were procured to facilitate electronic management of the OSCE assessment. Following the OSCE assessment, assessors were invited to evaluate the experience. RESULTS: Electronic software facilitated the storage and analysis of overall group and individual results thereby offering considerable time savings. Submission of electronic forms was allowed only when fully completed thus removing the potential for missing data. The feedback facility allowed the student to receive timely evaluation on their performance and to benchmark their performance against the class. CONCLUSIONS: Assessors' satisfaction with the software was high. Analysis of assessment results can highlight issues around internal consistency being moderate and examiners variability. Regression analysis increases fairness of result calculations.

The development and implementation of quality assurance programs to support nutritional measurements.

The National Institute of Standards and Technology administers quality assurance programs devoted to improving measurements of nutrients and related metabolites in foods, dietary supplements, and serum and plasma samples. These programs have been developed in collaboration with the National Institutes of Health to assist measurement communities in their efforts to achieve accurate results that are comparable among different laboratories and over time. Targeted analytes include micronutrients, botanical markers, nutritional elements, contaminants, fatty acids, and vitamin D metabolites.

Low social status impairs hypoxia tolerance in rainbow trout (Oncorhynchus mykiss).

In the present study, chronic behavioural stress resulting from low social status affected the physiological responses of rainbow trout (Oncorhynchus mykiss) to a subsequent acute stressor, exposure to hypoxia. Rainbow trout were confined in fork-length matched pairs for 48-72 h, and social rank was assigned based on behaviour. Dominant and subordinate fish were then exposed individually to graded hypoxia (final water PO(2), PwO(2) = 40 Torr). Catecholamine mobilization profiles differed between dominant and subordinate fish. Whereas dominant fish exhibited generally low circulating catecholamine levels until a distinct threshold for release was reached (PwO(2) = 51.5 Torr corresponding to arterial PO(2), PaO(2) = 24.1 Torr), plasma catecholamine concentrations in subordinate fish were more variable and identification of a distinct threshold for release was problematic. Among fish that mobilized catecholamines (i.e. circulating catecholamines rose above the 95% confidence interval around the baseline value), however, the circulating levels achieved in subordinate fish were significantly higher (459.9 ± 142.2 nmol L(-1), mean ± SEM, N = 12) than those in dominant fish (130.9 ± 37.9 nmol L(-1), N = 12). The differences in catecholamine mobilization occurred despite similar P(50) values in dominant (22.0 ± 1.5 Torr, N = 6) and subordinate (22.1 ± 2.2 Torr, N = 8) fish, and higher PaO(2) values in subordinate fish under severely hypoxic conditions (i.e. PwO(2) < 60 Torr). The higher PaO(2) values of subordinate fish likely reflected the greater ventilatory rates and amplitudes exhibited by these fish during severe hypoxia. At the most severe level of hypoxia, subordinate fish were unable to defend arterial blood O(2) content, which fell to approximately half (0.60 ± 0.13 mL O(2) g(-1) haemoglobin, N = 9) that of dominant fish (1.08 ± 0.09 mL O(2) g(-1) haemoglobin, N = 9). Collectively, these data indicate that chronic social stress impacts the ability of trout to respond to the additional, acute stress of hypoxia.

Interns' attitudes to IV cannulation: a KAP study.

UNLABELLED: One of the most common procedures for junior medical doctors is peripheral intravenous cannulation (PIVC). Considering this, an understanding of the peripheral intravenous cannulation procedure is paramount. AIM: The objective of this study was to identify the level of understanding of interns regarding intravenous cannulation. METHOD: An anonymized structured questionnaire using a knowledge attitude and practices (KAP) format was distributed to 60 interns affiliated to a university college hospital in Ireland. FINDINGS: This study suggests that interns are poorly prepared for one of the most common clinical skills they will perform. They showed poor understanding of whether peripheral cannulation is a clean or aseptic technique, and lacked knowledge of the potential side effects of peripheral cannulation and IV therapy. RECOMMENDATIONS: A structured learning module on peripheral intravenous cannulation is required. A rigid, evidence-based, Objective Structured Clinical Examination (OSCE) on peripheral cannulation is recommended. The reduction of junior doctors' weekly working hours to 48 under the European Working Time Directive offers the potential for nurses to take ownership of IV cannulation. This will allow junior doctors to focus on other clinical skills and assessments, which can only be to the advantage of the patient.

Certification of vitamins and carotenoids in SRM 3280 multivitamin/multielement tablets.

A new multivitamin/multielement dietary supplement Standard Reference Material (SRM) has been issued by the National Institute of Standards and Technology (NIST), with certified and reference concentration values for 13 vitamins, 24 elements, and 2 carotenoids. The constituents have been measured by multiple analytical methods with data contributed by NIST and by collaborating laboratories. This effort included the first use of isotope dilution mass spectrometry for value assignment of both fat-soluble vitamins (FSVs) and water-soluble vitamins (WSVs). Excellent agreement was obtained among the methods, with relative expanded uncertainties for the certified concentration values typically ranging from <2% to 15% for vitamins.

General practitioners' attitudes and preparedness towards Clinical Decision Support in e-Prescribing (CDS-eP) adoption in the West of Ireland: a cross sectional study.

BACKGROUND: Electronic clinical decision support (CDS) is increasingly establishing its role in evidence-based clinical practice. Considerable evidence supports its enhancement of efficiency in e-Prescribing, but some controversy remains. This study evaluated the practicality and identified the perceived benefits of, and barriers to, its future adoption in the West of Ireland. METHODS: This cross sectional study was carried out by means of a 27-part questionnaire sent to 262 registered general practitioners in Counties Galway, Mayo and Roscommon. The survey domains encompassed general information of individual's practice, current use of CDS and the practitioner's attitudes towards adoption of CDS-eP. Descriptive and inferential analyses were performed to analyse the data collected. RESULTS: The overall response rate was 37%. Nearly 92% of respondents employed electronic medical records in their practice. The majority acknowledged the value of electronic CDS in improving prescribing quality (71%) and reducing prescribing errors (84%). Despite a high degree of unfamiliarity (73%), the practitioners were open to the use of CDS-eP (94%) and willing to invest greater resources for its implementation (62%). Lack of a strategic implementation plan (78%) is the main perceived barrier to the incorporation of CDS-eP into clinical practice, followed by i) lack of financial incentives (70%), ii) lack of standardized product software (61%), iii) high sensitivity of drug-drug interaction or medication allergy markers (46%), iv) concern about overriding physicians' prescribing decisions(44%) and v) lack of convincing evidence on the systems' effectiveness (22%). CONCLUSIONS: Despite favourable attitudes towards the adoption of CDS-eP, multiple perceived barriers impede its incorporation into clinical practice. These merit further exploration, taking into consideration the structure of the Irish primary health care system, before CDS-eP can be recommended for routine clinical use in the West of Ireland.

Interobserver reliability of physical examination of shoulder girdle.

The object of this study was to assess interobserver reliability in 23 tests concerning physical examination of the shoulder girdle. A physical therapist and a physical therapist/manual therapist independently performed a physical examination of the shoulder girdle in 91 patients with shoulder complaints of varying severity and duration. The observers assessed 23 items in total: active and passive abductions, passive external rotation, hand in neck (HIN) test, hand in back (HIB) test, impingement test according to Neer, springing test of the first rib and joint play test of the acromioclavicular joint. The interobserver reliability was evaluated by means of a Cohen's Kappa, the weighted Kappa and the intraclass correlation (ICC). Criteria for acceptable reliability were: Kappa value>or=0.60, ICC>or=0.75 or an absolute agreement>or=80%. The results showed that Kappa values varied from 0.09 (springing test first rib, stiffness) to 0.66 (springing test first rib, pain), weighted Kappa varied from 0.35 (pain during HIB) to 0.73 (range of motion HIB) and ICC varied from 0.54 (abduction passive starting point painful arc) to 0.96 (active and passive ranges of motion in abduction). In total 11 (48%) items fulfilled the criteria of acceptable reliability. In conclusion, there appears to be a great deal of variation in the reliability of the tests used in the physical examination of the shoulder girdle. Over 50% of the tests did not meet the statistical criteria for acceptable reliability.

Effects of ageing on the biomechanical properties of rat articular cartilage.

Previous studies have demonstrated that male Sprague Dawley (SD) rats experience age-related bone loss with the same characteristics as that in ageing men. As articular cartilage, like bone, is a critical component of the health and function of the musculoskeletal system, the authors hypothesized that articular cartilage in the untreated male SD rats could be a suitable model for studying the age-related deterioration of articular cartilage in men. To test this hypothesis, male SD rats were killed at between 6 and 27 months. The right femur of each rat was removed. The effects of ageing on the structural integrity of the distal femoral articular cartilage were studied by biomechanical testing with a creep indentation apparatus. The aggregate modulus, Poisson's ratio, permeability, thickness, and percentage recovery of articular cartilage were determined using finite element/non-linear optimization modelling. No significant differences were observed in these biomechanical properties of the distal femoral articular cartilage as a function of age. Therefore, untreated male SD rats appear to be unsuitable for studying the age-related changes of articular cartilage as they occur in men. However, and more intriguingly, it is also possible that ageing does not affect the biomechanical properties of articular cartilage in the absence of cartilage pathology.

The impact of social status on the erythrocyte beta-adrenergic response in rainbow trout, Oncorhynchus mykiss.

The objective of the present investigation was to determine whether chronic increases in circulating cortisol concentrations, resulting from the occupation of subordinate status in rainbow trout social hierarchies, resulted in an enhancement of the erythrocyte adrenergic response. Rainbow trout (Oncorhynchus mykiss) were confined in fork length matched pairs for 6 h, 18 h, 48 h or 5-7 days, and social status was assigned through observations of behaviour. Erythrocyte adrenergic responsiveness, determined in vitro as changes in water content following incubation with the beta-adrenoreceptor agonist isoproterenol, was significantly greater in subordinate than dominant fish at 48 h of social interactions but not after 5-7 days, nor when assessed as changes in extracellular pH (pHe). However, the activity of the Na+/H+ exchanger (beta-NHE), assessed in vitro as the pHe change following incubation with the permeable cyclic AMP analogue 8-bromo-cyclic AMP, was significantly lower in subordinate fish. The number of erythrocyte membrane-bound adrenergic receptors (Bmax) was significantly higher in subordinate than dominant fish at 48 h, but had decreased by 5-7 days to a value that was not significantly different from that for dominant fish. The apparent dissociation constant (KD) of these receptors was not significantly impacted by either social status or interaction time. Finally, the relative expressions of beta-3b adrenergic receptor (AR) and beta-NHE mRNA were determined using real-time PCR and were found to be minimally affected by social rank. Relative to a control group, beta-3b AR mRNA was significantly up-regulated in both dominant and subordinate trout at all time periods, whereas the expression of beta-NHE was in general significantly down-regulated. Unlike the situation in rainbow trout treated with exogenous cortisol, elevations in circulating cortisol resulting from low social status did not "pre-adapt" the erythrocyte adrenergic response, but rather may have served to offset the potentially adverse effects elicited by plasma catecholamines, which were elevated during social hierarchy formation.

Repeated assessment of temporomandibular joint pain: reasoned decision-making with use of unidimensional and multidimensional pain scales.

BACKGROUND: There are no reports in the literature about patients with painfully restricted temporomandibular joints concerning the reliability of unidimensional and multidimensional pain scales on the basis of a generalizability and decision study. Generalizability and decision studies are designed to aid in reasoned decision-making and therefore are complementary to classic psychometric analyses, in which correlation coefficients express the reliability of a measurement design. The smallest detectable difference as an outcome of the decision study is the smallest statistically significant change that can be detected. PATIENTS: Twenty-five consecutive patients (5 males and 20 females) with painfully restricted mandibular function participated in the current study. DESIGN: Repeated measurements of three levels of unidimensional experienced pain (average, minimal, and maximal pain before the week of assessment; n = 200) and the multidimensional pain rating index of the MPQ (n = 100) were used. The measurement sessions were supervised by two observers on two separate measurement days, 1 week apart, with each measurement repeated twice. RESULTS: Inconsistency in measurement results analyzed in terms of absolute error variance (i.e., the measurement facets plus all the interactions) represented at least 24% of total variance. The smallest detectable difference of visual analog scales varied from 43 to 15 mm, depending on the amount of repetitions, whereas for the pain rating index it varied from 22.7 to 14.4 units. CONCLUSIONS: For statistically and clinically successful treatment of patients with painfully restricted temporomandibular joints, clinicians must overcome at least the smallest detectable difference and 38% of the initial average pain level.

Use of contrast echocardiography in the diagnosis of subacute myocardial rupture after myocardial infarction.

Myocardial rupture is an uncommon and catastrophic complication after acute myocardial infarction. It can present in an acute form or in a subacute form, with slower hemorrhage and thrombus formation at the site of rupture. These patients can survive several hours or days before the diagnosis is confirmed and the myocardial ruptured repaired. Two-dimensional Doppler echocardiography is very useful in the diagnosis of this complication, but the number of false-positive diagnoses is high, even in the presence of a large amount of pericardial effusion. In these patients, administration of a contrast agent can be useful to demonstrate active bleeding into the pericardium. We report a case of subacute myocardial rupture for which contrast echocardiography was useful in demonstrating the presence of persistent hemorrhage into the pericardium. To reduce the number of false-positive diagnoses, contrast echocardiography should be considered in patients with possible subacute myocardial rupture.

Identification of the first trans-(3R,4R)- dimethyl-4-(3-hydroxyphenyl)piperidine derivative to possess highly potent and selective opioid kappa receptor antagonist activity.

A structurally novel opioid kappa receptor selective ligand has been identified. This compound, (3R)-7-hydroxy-N-((1S)-1-[[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl]-2-methylpropyl)-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic, 10) demonstrated high affinity for the kappa receptor in the binding assay (kappa K(i) = 0.3 nM) and highly potent and selective kappa antagonism in the [(35)S]GTP-gamma-S assay using cloned opioid receptors (kappa K(i) = 0.006 nM, mu/kappa ratio = 570, delta/kappa ratio > 16600).

Effects of conjugated linoleic acids and docosahexaenoic acid on rat liver and reproductive tissue fatty acids, prostaglandins and matrix metalloproteinase production.

Long chain n-6 and n-3 fatty acids play important roles in labor and delivery. These effects may be mediated by prostaglandin (PG) synthesis and by regulation of matrix metalloproteinases (MMPs), both of which play roles in uterine contraction, cervical ripening and rupture of fetal membranes. The effects of altering dietary n-6:n-3 long chain fatty acid ratios, and the addition of dietary conjugated linoleic acids (CLA) and docosahexaenoic acid (DHA) on fatty acid composition of reproductive tissues, PG synthesis in liver and reproductive tissue and serum MMP levels were examined in pregnant rats. Modified AIN-96G diets with n-6:n-3 ratios of 7:1 and 34:1 with and without added 1.1% (by weight) conjugated linoleic acid (CLA) and/or 0.3% (by weight) DHA were fed through day 20 of gestation. Reproductive tissues readily incorporated both DHA and CLA. CLA significantly (P<0.05) depressed PGF(2 alpha)synthesis in placenta, uterus and liver by 50% when the n-6:n-3 ratio was 7:1 and by 66% at 34:1 ratio. Significant differences (P<0.05) in PGE(2)synthesis in uterus and liver were seen only between groups fed the high ratio of n-6:n-3 without CLA, and the low ratio with CLA. Addition of CLA to DHA containing diets depressed PGF(2alpha) by one-third in uterus and liver (P<0.05). Serum MMP-9 and active MMP-2 were suppressed (P<0.05) by addition of either CLA or DHA.