Evidence-based Indications for Vertebral Body Tethering in Spine Deformity

Posterior spinal fusion has long been established as an effective treatment for the surgical management of spine deformity. However, interest in nonfusion options continues to grow. Vertebral body tethering is a nonfusion alternative that allows for the preservation of growth and flexibility of the spine. The purpose of this investigation is to provide a practical and relevant review of the literature on the current evidence-based indications for vertebral body tethering. Early results and short-term outcomes show promise for the first generation of this technology. At this time, patients should expect less predictable deformity correction and higher revision rates. Long-term studies are necessary to establish the durability of early results. In addition, further studies should aim to refine preoperative evaluation and patient selection as well as defining the benefits of motion preservation and its long-term effects on spine health to ensure optimal patient outcomes.

Radiation exposure in navigated techniques for AIS: is there a difference between pre-operative CT and intraoperative CT?

PURPOSE

Utilization of navigation improves pedicle screw accuracy in adolescent idiopathic scoliosis (AIS). Our center switched from intraoperative CT (ICT) to an optical navigation system that utilizes pre-operative CT (PCT). We aim to evaluate the radiation dose and operative time for low-dose ICT compared to standard and low-dose PCT used for optical navigation in AIS patients undergoing posterior spinal fusion.

METHODS

A single-center matched-control cohort study of 38 patients was conducted. Nineteen patients underwent ICT navigation (O-arm) and were matched by sex, age, and weight to 19 patients who underwent PCT for use with an optical-guided navigation (7D, Seaspine). A total of 418 levels were instrumented and reviewed. PCT was either a standard dose (N = 7) or a low dose (N = 12). The mean volume CT dose index, dose-length product, overall effective dose (ED), ED per level instrumented, and operative time per level were compared.

RESULTS

ED per level instrumented was 0.061 ± 0.029 mSv in low-dose PCT and 0.14 ± 0.05 mSv in low-dose ICT (p < 0.0001). ED per level instrumented was significantly higher in standard PCT (1.46 ± 0.39 vs. 0.14 ± 0.03 mSv; p < 0.0001). Mean operative time per level was 31 ± 7 min for ICT and 33 ± 3 min for PCT (p = 0.628).

CONCLUSION

Low-dose PCT resulted in 0.70 mSv exposure per case and 31 min per level, standard-dose was 16.95 mSv, while ICT resulted in 1.34-1.62 mSv and a similar operative time. Use of a standard-dose PCT involves radiation exposure about 9 times higher than ICT and 23 times higher than low-dose PCT per level instrumented.

LEVEL OF EVIDENCE

Level III.

Proximal Humerus Reconstruction for Bone Sarcomas: A Critical Analysis

» The proximal humerus is a common location for primary bone tumors, and the goal of surgical care is to obtain a negative margin resection and subsequent reconstruction of the proximal humerus to allow for shoulder function.» The current evidence supports the use of reverse total shoulder arthroplasty over hemiarthroplasty when reconstructing the proximal humerus after resection of a bone sarcoma if the axillary nerve can be preserved.» There is a lack of high-quality data comparing allograft prosthetic composite (APC) with endoprosthetic reconstruction of the proximal humerus.» Reverse APC should be performed using an allograft with donor rotator cuff to allow for soft-tissue repair of the donor and host rotator cuff, leading to improvements in shoulder motion compared with an endoprosthesis.

Oncological and functional outcomes after resection of malignant tumours of the scapula

Aims

The scapula is a rare site for a primary bone tumour. Only a small number of series have studied patient outcomes after treatment. Previous studies have shown a high rate of recurrence, with functional outcomes determined by the preservation of the glenohumeral joint and deltoid. The purpose of the current study was to report the outcome of patients who had undergone tumour resection that included the scapula.

Methods

We reviewed 61 patients (37 male, 24 female; mean age 42 years (SD 19)) who had undergone resection of the scapula. The most common resection was type 2 (n = 34) according to the Tikhoff-Linberg classification, or type S1A (n = 35) on the Enneking classification.

Results

The ten-year disease-specific survival was 76%. High tumour grade (hazard ratio (HR) 4.27; p = 0.016) and a total resection of the scapula (HR 3.84; p = 0.015) were associated with worse survival. The ten-year metastasis-free and local recurrence-free survivals were 82% and 86%, respectively. Total scapular resection (HR 6.29; p = 0.004) was associated with metastatic disease and positive margins were associated with local recurrence (HR 12.86; p = 0.001). At final follow-up, the mean shoulder forward elevation and external rotation were 79° (SD 62°) and 27° (SD 25°), respectively. The most recent functional outcomes evaluated included the mean Musculoskeletal Tumor Society Score (76% (SD 17%)), the American Shoulder and Elbow Score (73% (SD 20%)), and the Simple Shoulder Test (7 (SD 3)). Preservation of the glenoid (p = 0.001) and scapular spine (p < 0.001) improved clinical outcomes; interestingly, preservation of the scapular spine without the glenoid improved outcomes (p < 0.001) compared to preservation of the glenoid alone (p = 0.05).

Conclusion

Resection of the scapula is a major undertaking with an oncological outcome related to tumour grade, and a functional outcome associated with the status of the scapular spine and glenoid. Positive resection margins are associated with local recurrence.

Targeted Muscle Reinnervation to Reduce Postoperative Pain in Patients Undergoing Hindquarter Resections

BACKGROUND/AIM

Pre-emptive targeted muscle reinnervation (TMR) at the time of amputation results in less phantom limb pain (PLP) compared with untreated amputee controls. There is limited literature describing the technique in patients undergoing hindquarter amputation despite up to 90% of these patients reporting PLP and 50% presenting with painful neuroma. The purpose of the current study was to describe the motor nerves accessible through a primary hind-quarter amputation to be used for TMR and review pain outcomes in clinical case correlates of patients with TMR.

PATIENTS AND METHODS

Six limbs were obtained from three fresh adult cadavers and proximal sensory and motor nerves were dissected. A review of patients undergoing hindquarter amputation with TMR was conducted.

RESULTS

Transfers for the sciatic, femoral, and obturator nerves were identified in cadavers. In reviews of patients, they were taking narcotic and neuro-leptic pain medication for a mean of 23 days and 168 days. At most recent follow-up, no patient reported debilitating phantom pain nor pain associated with neuromas.

CONCLUSION

Given the positive preliminary results in our study group as well as the accessible neuroanatomy, pre-emptive TMR should be considered at the time of surgery to limit PLP and dependence on pain medications.

Management of giant cell tumors of the distal radius

Background

The distal radius is the most common location for giant cell tumors (GCT) in the upper extremity. Treatment should balance the goals of maximizing function and minimizing recurrence and other complications. Given the complexity in surgical treatment, various techniques have been described without clear standards of treatment.

Objectives

The purpose of this review is to provide an overview of evaluation of patients presenting with GCT of the distal radius, discuss management, and provide an updated summary on outcomes of treatment options.

Conclusion

Surgical treatment should consider tumor Grade, involvement of the articular surface, and patient-specific factors. Options include intralesional curettage and en bloc resection with reconstruction. Within reconstruction techniques, radiocarpal joint preserving and sparing procedures can be considered. Campanacci Grade 1 tumors can be successfully treated with joint preserving procedures, whereas for Campanacci Grade 3 tumors consideration should be given to joint resection to prevent recurrence. Treatment of Campanacci Grade 2 tumors is debated in the literature. Intralesional curettage and adjuvants can successfully treat cases where the articular surface can be preserved, while en-bloc resection should be used in cases where the articular surface cannot undergo aggressive curettage. A variety of reconstructive techniques are used for cases needing resection, with no clear gold standard. Joint sparing procedures preserve motion at the wrist joint, whereas joint sacrificing procedures preserve grip strength. Choice of reconstructive procedure should be made based on patient-specific factors, considering relative functional outcomes, complications, and recurrence rates.

Does Shorter Time to Treatment of Pediatric Supracondylar Humerus Fractures Impact Clinical Outcomes?

BACKGROUND

Treatment of supracondylar humerus (SCH) fractures within 18 hours of presentation is a tracked quality metric for ranking of pediatric hospitals. This is in contrast with literature that shows time to treatment does not impact outcomes in SCH fractures. We aim to determine whether an 18-hour cutoff for pediatric supracondylar humerus fracture treatment is clinically significant by comparing the complication risks ofpatients on either side of this timepoint. Our hypothesis is that there will be no statistically significant differences based on time to treatment.

METHODS

A retrospective review of clinical outcomes was performed for 472 pediatric patients who underwent surgical management of isolated supracondylar humerus fractures between 1997 and 2022 at a single level I pediatric trauma hospital. The cohort was split based on time to surgery (within or ≥18 h from Emergency Department admission).

RESULTS

Surgical treatment occurred within 18 hours of arrival in 435 (92.2%) patients and after 18 hours in 37 (7.8%) patients. Mean age was 5.6±2.2 years and 51.5% of patients were female. Gartland fracture classification was type II [n=152 (32.3%)], type III [n=284 (60.3%)], type IV [n=13 (2.8%)], or flexion-type [n=18 (3.8%)]. There were no differences in demographic characteristics or fracture classification between cohorts. Fractures in the ≥18-hour cohort were treated more commonly with 2 pins (62.2% vs. 38.5%, P =0.04). There were no statistically significant differences in open versus closed reduction, utilization of medial pins, or postoperative immobilization between cohorts. We were unable to detect any differences in postoperative complications, including non-union, delayed union, stiffness, malunion, loss of reduction, iatrogenic nerve injury, or infection. This remained true when type II fractures were excluded.

CONCLUSIONS

Using an arbitrary time cutoff of <18 hours does not influence clinical outcomes in the surgical treatment of SCH fractures. This held true when type II fractures were excluded. For this reason, we recommend modification to the USNWR guidelines to decrease emphasis on time-to-treatment of SCH fractures.

LEVEL OF EVIDENCE

Level III.

Comparison of Fixation Techniques for Lower Extremity Rotationplasty

BACKGROUND

Rotationplasty is a reconstructive, limb-sparing surgery indicated for patients with lower extremity musculoskeletal tumors. The procedure involves rotation of the distal lower extremity to allow the ankle to function as the new knee joint and provide an optimum weight-bearing surface for prosthetic use. Historically there is limited data comparing fixation techniques. The purpose of this study is to compare clinical outcomes between intramedullary nailing (IMN) and compression plating (CP) in young patients undergoing rotationplasty.

METHODS

A retrospective review of 28 patients with a mean age of 10±4 years undergoing a rotationplasty for either a femoral (n=19), tibial (n=7), or popliteal fossa (n=2) tumor was performed. The most common diagnosis was osteosarcoma (n=24). Fixation was obtained with either an IMN (n=6) or CP (n=22). Clinical outcomes of patients undergoing rotationplasty were compared between the IMN and CP groups.

RESULTS

Surgical margins were negative in all patients. The mean time to union was 24 months (range 6 to 93). There was no difference in the meantime to the union between patients treated with an IMN versus those with a CP (14±16 vs. 27±26 mo, P=0.26). Patients undergoing fixation with an IMN were less likely to have a nonunion (odds ratio: 0.35, 95% confidence interval: 0.03-3.54, P=0.62). Postoperative fracture of the residual limb only occurred in patients undergoing CP fixation (n=7, 33% vs. n=0, 0%, P=0.28). Postoperative fixation complications occurred in 13 (48%) patients, most commonly a nonunion (n=9, 33%). Patients undergoing fixation with a CP were more likely to have a postoperative fixation complication (odds ratio: 20, 95% CI: 2.14-186.88, P<0.01).

CONCLUSIONS

Rotationplasty is an option for limb salvage for young patients with lower extremity tumors. The results of this study reveal fewer fixation complications when an IMN can be used. As such, IMN fixation should be considered for patients undergoing a rotationplasty, though equipoise should be shown by surgeons when determining technique.

The AAHKS Clinical Research Award: Resurfacing the Thin Native Patella: Is It Safe?

BACKGROUND

Whether to resurface the patella during total knee arthroplasty (TKA) remains debated. One often cited reason for not resurfacing is inadequate patellar thickness. The aim of this study was to describe the implant survivorships, reoperations, complications and clinical outcomes in patients who underwent patellar resurfacing of a thin native patella.

METHODS

From 2000 to 2010, 7,477 patients underwent primary TKA with patellar resurfacing and had an intraoperatively, caliper-measured patella thickness at our institution. Of these, 200 (2.7%) had a preresection patellar thickness of ≤19 millimeters (mm). Mean preresection thickness was 18 mm (range, 12-19). Mean age was 69 years, mean body mass index was 31 kg/m², and 93% of the patients were women. Median follow-up was 10 years (range, 2-20).

RESULTS

At 10 years, survivorships free of any patella revision, patella-related reoperation, and periprosthetic patella fracture were 98%, 98%, and 99%, respectively. There were 3 patella revisions (1 aseptic loosening, 2 periprosthetic joint infections). There were 2 additional patella-related reoperations for patellar clunk. There were 3 nonoperatively managed periprosthetic patella fractures. Radiographically, all nonrevised knees had well-fixed patellae. Knee society scores improved from mean 36 points (interquartile range [IQR] 24-49) preoperatively to mean 81 points (IQR 77-81) at 10-year follow-up.

CONCLUSION

Resurfacing the thin native patella was associated with high survivorship free of patellar revision at 10-year follow-up. Nevertheless, there was 1 case of patellar loosening and 3 periprosthetic patella fractures. These risks must be weighed against the known higher incidence of revision when the thin native patella is left unresurfaced.

Complications With Surgical Treatment of Pediatric Supracondylar Humerus Fractures: Does Surgeon Training Matter?

INTRODUCTION

National trends reveal increased transfers to referral hospitals for surgical management of pediatric supracondylar humerus (SCH) fractures. This is partly because of the belief that pediatric orthopaedic surgeons (POs) deliver improved outcomes compared with nonpediatric orthopaedic surgeons (NPOs). We compared early outcomes of surgically treated SCH fractures between POs and NPOs at a single center where both groups manage these fractures.

METHODS

Patients ages 3 to 10 undergoing surgery for SCH fractures from 2014 to 2020 were included. Patient demographics and perioperative details were recorded. Radiographs at surgery and short-term follow-up assessed reduction. Primary outcomes were major loss of reduction (MLOR) and iatrogenic nerve injury (INI). Complications were compared between PO-treated and NPO-treated cohorts.

RESULTS

Three hundred and eleven fractures were reviewed. POs managed 132 cases, and NPOs managed 179 cases. Rate of MLOR was 1.5% among POs and 2.2% among NPOs (P=1). Rate of INI was 0% among POs and 3.4% among NPOs (P=0.041). All nerve palsies resolved postoperatively by mean 13.1 weeks. Rates of reoperation, infection, readmission, and open reduction were not significantly different. Operative times were decreased among POs (38.1 vs. 44.6 min; P=0.030). Pin constructs were graded as higher quality in the PO group, with a higher mean pin spread ratio (P=0.029), lower rate of "C" constructs (only 1 "column" engaged; P=0.010) and less frequent crossed-pin technique (P<0.001). Multivariate analysis revealed minimal positive associations only for operative time with MLOR (odds ratio=1.021; P=0.005) and INI (odds ratio=1.048; P=0.009).

CONCLUSIONS

Postsurgical outcomes between POs and NPOs were similar. Rates of MLOR were not different between groups, despite differences in pin constructs. The NPO group experienced a marginally higher rate of INI, though all injuries resolved. Pediatric subspecialty training is not a prerequisite for successfully treating SCH fractures, and overall value of orthopaedic care may be improved by decreasing transfers for these common injuries.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

How Much Opioid Do Kids Actually Need? A Prospective Study of Analgesic Prescribing and Postdischarge Opioid Use Among Pediatric Patients With Operative Fractures

BACKGROUND

Analgesic guidelines are lacking for most operative pediatric fractures, and little is known about postdischarge opioid use or pain control. We hypothesized that opioid/acetaminophen/non-steroidal anti-inflammatory drugs (NSAID) prescribing would vary, pain would be well controlled, and postdischarge opioid use would be low.

METHODS

This prospective cohort study included nonpolytraumatized patients aged 17 years and below with operative fractures at a level 1 trauma center from August 1, 2019 to March 31, 2021. Supracondylar humerus fractures were excluded since they have been studied extensively. Information regarding injury/surgery/analgesics were collected. Discharged patients were called on postoperative days (POD) 1/3/5. Parents/guardians were asked about analgesic use and pain over the preceding 2 days. Complications, pain control, and opioid refills were recorded after first follow-up.

RESULTS

All 100 eligible patients were included. Mean age was 10.1 years (range: 1.8 to 17.8 y). Common fracture types were humeral condyle/epicondyle (28%), radius/ulna (15%), and femoral shaft (13%). Opioids were prescribed to 95% of patients with mean 14 doses (range: 2 to 45). Acetaminophen/NSAIDs were prescribed to 74% and 60% of patients, respectively. Eleven patients were excluded from telephone follow-up (7 non-English speaking, 3 prohibitive social situations, 1 inpatient POD1 to 5). Telephone follow-up was completed for 87/89 eligible patients (98%). Mean pain scores declined from 3.7/10 POD1 to 2.4/10 POD5. Opioids were taken by 50% POD1, 20% POD5. Acetaminophen/NSAID was given before opioid 82% of the time. By POD5, mean total doses of opioid taken postdischarge was 2.3; mean proportion of prescribed opioid doses taken was 22%; and 97% of patients took ≤8 opioid doses postdischarge. Two patients were evaluated early due to poor pain control which improved with cast changes. Pain was well controlled or absent at follow-up in 97% of patients.

CONCLUSIONS

Pain is consistently well controlled after operative pediatric fractures. Nearly all were prescribed opioids, while acetaminophen/NSAIDs were inconsistently prescribed and used. Opioid prescriptions are written for 4 to 5 times the amount needed. Prescribing ≤8 doses of opioid is adequate for acute pain through POD5 in 97% of patients. Poorly controlled pain should prompt early evaluation for possible complications.

LEVEL OF EVIDENCE

Level II-prospective comparative study.

Identifying meaningful dietary intake and physical activity questions for individual and population health

We aimed to identify valid screening questions for adults regarding physical activity and dietary behaviours that (a) were correlated with BMI, (b) were deemed by patients and providers to be relevant to clinical care, and (c) have utility for longitudinal understanding of health behaviours in populations. The goal was to identify screening questions that could be implemented at annual health care visits. First, we identified dietary behaviour questions and solicited patient input. Next, we tested both physical activity and dietary behaviour questions in a large sample to test their potential utility. Finally, we used cognitive interviews with patients and physicians to narrow our assessment for clinical settings. We present a parsimonious and reliable six-question scale of physical activity and dietary behaviours for research settings, as well as a three-question scale for clinical settings. We demonstrate a robust relationship between these measures and obesity. Additionally, we present evidence that these measures may serve as a useful red flag for patients before they develop obesity. We provide a concise and useful tool for assessing patients' physical activity and dietary behaviours in a variety of research settings. We also highlight the importance of incorporating this tool into the clinical intake flow for inclusion in patients' Electronic Health Record.

Development of Brief Child Nutrition and Physical Activity Screening Questions for Electronic Health Record Use

Background: To develop and test brief nutrition and physical activity screening questions for children ages 2-11 years that could be used as a pragmatic screening tool to tailor counseling, track behavior change, and improve population health. Methods: A literature review identified existing validated questions for nutrition and physical activity behaviors in children ages 2-11 years. Response variation and concurrent validity was then assessed using a mechanical Turk (MTurk) crowdsourcing survey employed in 2018. Additionally, cognitive interviews were conducted with both providers and parents of 2- to 11-year-old children to assess screening question priorities and perceived added value. Results: The literature review identified 260 questions, and 20 items were selected with expert guidance based on prespecified criteria (simplicity and potential utility for both clinical interactions during a well-child exam and population health). MTurk surveys yielded 1147 records that met eligibility criteria and revealed 6 items that had adequate response variation and were significantly correlated with parent-reported child BMI or BMI percentile, exhibiting concurrent validity. Cognitive interviews with 10 providers and 20 parents uncovered themes regarding suggestions and usability of the questions, eliminating 3 items due to parent and provider concerns. Combining quantitative and qualitative results, 3 nutrition and physical activity screening items remained for inclusion into the electronic health record (EHR). Conclusions: The three-pronged validation methodology produced a brief, 3-item child nutrition and physical activity screener to incorporate in the EHR, where it can inform tailored counseling for well-child care and be used to test associations with population health outcomes.

Impaired retrograde transmission of vasodilatory signals via the endothelium in pre-eclampsia: a cause of reduced tissue blood flow?

There is evidence that tissue blood flow is regulated by retrograde transmission of signals initiated at capillary and post-capillary sites, and transmitted via the endothelium to modulate pre-capillary resistance. We have used pre-eclampsia as a model to test the hypothesis that normal endothelium is required to enable adjustment of blood flow to match tissue requirements. Integrity of the endothelial pathway was assessed by measuring calf blood flow at increasing venous pressures, using an established small cumulative-step venous-congestion plethysmography protocol in ten women with pre-eclampsia, 17 normal pregnant controls and ten non-pregnant women. Endothelial cell activation was assessed by measuring plasma levels of the cell adhesion molecules, intercellular cell-adhesion molecule-1 (ICAM-1), vascular cell-adhesion molecule-1 (VCAM-1) and E-selectin. Baseline calf blood flow was significantly lower in pre-eclampsia than in the other two groups (P<0.0001; ANOVA). In the pre-eclampsia group, there was a fall in blood flow as venous congestion pressure was raised (P<0.0001; ANOVA). No such change was observed in the other two groups. A significant inverse correlation was observed between the reduction in blood flow in pre-eclampsia and the levels of E-selectin (r=-0.92, P=0.0002), VCAM-1 (r=-0.93, P=0.0008) and ICAM-1 (r=-0.86, P=0.001). The differences between the pre-eclamptic women and the other two groups support the notion that the failure to sustain blood flow during a cumulative pressure step protocol in the pre-eclamptic group might be influenced by interference with the retrograde transmission of signals via the endothelium in these patients.

Evidence of impaired microvascular function in pre-eclampsia: a non-invasive study

The clinical presentation of pre-eclampsia suggests that microvascular dysfunction may play a role in the maternal manifestations of the disease. Isovolumetric venous pressure ( P V(i)) is an index of microvascular function, reflecting local plasma colloid osmotic (oncotic) pressure, and is abnormal in clinical conditions with microvascular dysfunction. We hypothesized that, in pre-eclampsia, post-capillary margination of neutrophils would increase post-capillary resistance, and therefore P V(i). A small cumulative step strain-gauge plethysmography protocol was used to compare P V(i) in 18 women with pre-eclampsia, 16 normal pregnant women and 17 non-pregnant controls. Circulating levels of vascular cell-adhesion molecule-1 (VCAM-1), intercellular cell-adhesion molecule-1 (ICAM-1) and E-selectin, and neutrophil elastase, were measured to assess endothelial and neutrophil activation respectively. P V(i) was significantly greater in the pre-eclampsia group, relative to the normal pregnant and non-pregnant controls ( P <0.001, ANOVA, for both comparisons). P V(i) was significantly lower during normal pregnancy compared with the non-pregnant controls ( P =0.001). Plasma levels of neutrophil elastase, VCAM-1, ICAM-1 and E-selectin ( P =0.001) were significantly greater in the pre-eclamptics than the controls. Significant positive correlations were observed between P V(i) and neutrophil elastase ( r =0.71, P =0.001), VCAM-1 ( r =0.52, P =0.03), ICAM-1 ( r =0.67, P =0.002), E-selectin ( r =0.69, P =0.001), uric acid levels ( r =0.54, P =0.02) and haematocrit ( r =0.64, P =0.004) in pre-eclampsia. The relationship with the platelet count was negative ( r =-0.65, P =0.003). No significant correlations were observed between P V(i) and maternal age, gestational age, total protein, albumin, diastolic blood pressures, age, body mass index and infant birth mass in the normal pregnant and non-pregnant controls. These data suggest that microvascular dysfunction occurs in pre-eclampsia, and that it is related to alterations in endothelial cell and neutrophil activation.

Changes in the effects of interleukin-1beta and tumor necrosis factor-alpha on platelet activation in early pregnancy

Platelets are known to be activated in normal pregnancy, and are further activated in pathological pregnancy states, such as preeclampsia. The factors controlling platelet activation are unknown, but cytokines, such as interleukin 1beta (IL-1beta) and tumor necrosis-alpha (TNF-alpha) have been found to affect platelet function and are believed to be involved in early pregnancy. We assessed the effects of these cytokines on platelets from women at various stages of pregnancy. We compared two methods: platelet in vitro aggregation by aggregometry, and platelet P-selectin expression by flow cytometry. IL-1beta and TNF-alpha had no effect on the in vitro aggregation and P-selectin expression of platelets from women in the first trimester of pregnancy as compared to the inhibitory effects of both in late pregnancy. We conclude that maternal platelet function undergoes a marked change throughout pregnancy.

Intrauterine T-cell activation and increased proinflammatory cytokine concentrations in preterm infants with cerebral lesions

Brain injury is common in very preterm infants, and intrauterine infection is a frequent antecedent of preterm birth. We examined the relation of cerebral damage to intrauterine antigen exposure and inflammation in 50 infants who were born at 23-29 weeks' gestation. Higher concentrations of cytokines (tumour necrosis factor alpha [TNF-alpha], and interleukins [IL], 1beta, 6, and 10) and CD45RO(+) T lymphocytes in umbilical blood predicted cerebral lesions detected by magnetic resonance imaging very soon after delivery. Our results suggest that infants who mount an immune response in utero are at higher risk of cerebral lesions.

IL-1beta and IL-8 in human fetal membranes: changes with gestational age, labor, and culture conditions

PROBLEM

Interleukin (IL)-1beta and IL-8 are associated with labor. This study aimed to characterize their concentrations in fetal membranes and any changes in these with advancing gestation and to define as to whether there are interactions between the membranes in their expression.

METHOD OF STUDY

mRNA and protein content of amnion and choriodecidua at increasing gestations and before and after labor at term were quantified. Membranes were also collected before and after labor, separated, and cultured. Protein production was measured by ELISA.

RESULTS

IL-1beta and IL-8 concentration increased in third trimester amnion and choriodecidua. Further increased expression of mRNA of both cytokines was found after labor in both membranes except IL-8 production by amnion. Choriodecidua produced more of each cytokine than amnion, however, no interaction between the membranes was demonstrated by culture.

CONCLUSIONS

Increasing expression of IL-1beta and IL-8 in amnion and choriodecidua in the third trimester and after labor supports a role for these cytokines in the establishment of labor.

Localisation of mRNAs for diamine oxidase and histamine receptors H1 and H2, at the feto-maternal interface of human pregnancy

OBJECTIVE AND DESIGN

To localise mRNAs for the histamine receptors H1, H2 and H3, and for diamine oxidase, in the placenta and decidua of the human feto-maternal interface.

MATERIALS AND METHODS

Complementary DNA for each mRNA of interest was amplified by polymerase chain reaction. Sub-cloned sequences were used to prepare probes for in situ hybridisation, and these were employed to localise the expression of mRNAs for histamine receptors H1 and H2, and for diamine oxidase.

RESULTS

mRNA for histamine receptors H1 and H2, and for diamine oxidase could be detected at the feto-maternal interface of human pregnancy, and localised to both decidual and placental cells.

CONCLUSION

The co-expression of these receptors and DAO is consistent with a role for histamine at the feto-maternal interface of human pregnancy.

Blood eosinophils from atopic donors express messenger RNA for the alpha, beta, and gamma subunits of the high-affinity IgE receptor (Fc epsilon RI) and intracellular, but not cell surface, alpha subunit protein

BACKGROUND

Blood eosinophils from hypereosinophilic donors were previously reported to possess the functional high-affinity IgE receptor (Fc epsilon RI), so providing a potential mechanism to account for eosinophil degranulation in atopic allergic disease. Furthermore, tissue eosinophils from allergic tissue reactions were shown to be mRNA(+) for the alpha, beta, and gamma subunits of Fc epsilon RI and gave positive immunostaining with an anti-Fc epsilon RI-alpha antibody. Recent studies, however, revealed negative surface staining on peripheral blood eosinophils, but intracellular Fc epsilon RI-alpha protein was identified by Western blot analysis.

OBJECTIVE

Our purpose was to examine on peripheral blood eosinophils from atopic subjects (1) surface expression and mRNA for Fc epsilon RI-alpha, (2) up-regulation of Fc epsilon RI-alpha by allergy-associated tissue factors, and (3) Fc epsilon RI-alpha-dependent release of eosinophil peroxidase (EPO).

METHODS

We measured (1) Fc epsilon RI mRNA expression by in situ hybridization, (2) Fc epsilon RI-alpha by flow cytometry and immunocytochemistry (with use of nonpermeabilized and permeabilized cells), and (3) Fc epsilon RI-alpha-dependent release of EPO.

RESULTS

Eosinophils from atopic donors had negligible surface expression of Fc epsilon RI-alpha, which was not enhanced by culture with IgE, IL-3, IL-4, IL-5, GM-CSF, or fibronectin or coculture with fibroblasts. Permeabilization, however, revealed appreciable intracellular staining for Fc epsilon RI-alpha. The majority of eosinophils were mRNA(+) for the alpha, beta, and gamma subunits of Fc epsilon RI. Small but significant (P =.03) increases in alpha chain mRNA expression were observed after coculture of eosinophils with fibroblasts but not with IgE, IL-4, or fibronectin. Cross-linking of Fc epsilon RI on the surface of eosinophils from atopic donors did not lead to detectable EPO release.

CONCLUSION

Human blood eosinophils express negligible, nonfunctional membrane Fc epsilon RI-alpha but have intracellular Fc epsilon RI-alpha protein and mRNA expression for the alpha, beta, and gamma subunits.

The regulation of prostaglandin output from term intact fetal membranes by anti-inflammatory cytokines

Prostaglandins are some of the main mediators which control parturition, and their production by intrauterine tissues can be up-regulated by pro-inflammatory cytokines. Anti-inflammatory cytokines may oppose these effects, and in this study we have investigated how two such cytokines affected fetal membrane function. Interleukin-10 (IL-10) inhibited the output of prostaglandin E2 (PGE2) from intact fetal membranes under basal and lipopolysaccharide (LPS)-stimulated conditions, and there was a parallel decrease in the expression of mRNA for COX-2. IL-10 also inhibited the production of interleukin-1beta (IL-1beta) and the expression of mRNA for IL-1beta, indicating that this cytokine has a broad anti-inflammatory effect. Transforming growth factor-beta1 (TGF-beta1), which is generally considered to be anti-inflammatory had opposite effects on PGE2 production, in that it increased the output of PGE2 for up to 8 hr. TGF-beta1 increased levels of type-2 cyclo-oxygenase (COX-2) and cytosolic phospholipase A2 (cPLA2) protein, and also activated the cPLA2 enzyme present; the profile of effects is similar to that of the pro-inflammatory cytokine IL-1beta, and was not expected. Combinations of TGF-beta1 with IL-1beta also increased PGE2 output and caused appropriate changes in prostaglandin pathway enzymes, whereas TGF-beta1 and IL-1alpha had more limited effects. Further studies are needed to establish the physiological significance of these findings, but TGF-beta1 does not seem to act as an inhibitory cytokine in intact fetal membranes at term.

The roles of the cyclo-oxygenases types one and two in prostaglandin synthesis in human fetal membranes at term

The aim of this study was to determine the relative contributions of cyclo-oxygenase (COX) types 1 and 2 to prostaglandin synthesis at term.

METHODS

Fetal membranes were collected from 6 pregnancies after elective caesarean section at term, prior to labour. The presence of COX-1 and COX-2 protein was determined using Western analysis. The relative contributions of the two isoforms of COX to prostaglandin synthesis were determined by incubation of fetal membrane discs with either a COX-2 selective inhibitor, SC236, or a COX-1 selective inhibitor, SC560, and measurement of prostaglandin release during 24 h using enzyme-linked immuno-sorbent assay (ELISA).

RESULTS

Both COX-1 and COX-2 protein were demonstrated in amnion and chorion-decidua. The COX-2 selective inhibitor, SC-236, significantly reduced prostaglandin synthesis, both in its COX-2 specific and higher, non-specific concentration ranges. The COX-1 selective inhibitor, SC-560, had no effect upon prostaglandin synthesis in its COX-1 specific concentration range, but did significantly reduce prostaglandin synthesis at higher, non-selective concentrations.

CONCLUSIONS

Fetal membranes contain both COX-1 and COX-2 at term, but only COX-2 contributes towards prostaglandin synthesis. COX-2 selective NSAI drugs will be as effective as non-selective agents in inhibition of fetal membrane prostaglandin synthesis and may represent a new strategy for tocolysis.

Expression of 5-lipoxygenase and 5-lipoxygenase-activating protein in human fetal membranes throughout pregnancy and at term

Lipoxygenase metabolites may be involved in human parturition. 5-lipoxygenase (5-LOX) catalyses the first steps in the synthesis of leukotrienes from arachidonic acid, and its activity is dependent on 5-LOX activating protein (FLAP). The expression of 5-LOX and FLAP were investigated in fetal membranes to determine whether there are changes with gestational age or at term with the onset of labour. No significant differences were found in the expression of 5-LOX or FLAP mRNA in the amnion at different gestational ages or at term. In the chorion-decidua, 5-LOX mRNA expression was significantly higher in the first trimester of pregnancy than in the second and third trimesters. At term, there was a significant increase in both 5-LOX mRNA and protein expression in the chorion-decidua in the time after labour, compared with the time before labour. The expression of FLAP mRNA was also significantly higher in the chorion-decidua in the first trimester of pregnancy compared with the third trimester, and at term in the time after labour compared with the time before labour. Expression of FLAP protein was not studied, as an antibody is not currently available. These results are consistent with a role for 5-LOX and FLAP in the control of parturition at term, and also suggest an involvement earlier in pregnancy.

The production of interleukin-1beta from human fetal membranes is not obligatory for increased prostaglandin output

Bacterial endotoxin increased the expression of mRNA (maximal after 4 hr) for interleukin-1beta (IL-1beta) and the release of mature protein from intact human fetal membranes. In contrast, the change in expression of mRNA for type 2 cyclo-oxygenase (COX-2) was biphasic, with peaks after 0.5-1 hr and after 8 hr of culture. An antibody to IL-1beta was without effect after 4 hr of culture, inhibited endotoxin-stimulated prostaglandin E2 (PGE2) production after 8 hr of culture, and caused a parallel decrease in the expression of mRNA for COX-2. We conclude that endotoxin induced the expression of COX-2 through IL-1beta-independent and IL-1beta-dependent mechanisms, and these differences are time dependent. Corticotrophin-releasing hormone (CRH) or platelet-activating factor (PAF) also increased the expression of mRNA for IL-1beta and the release of IL-1beta from some, but not all, fetal membranes. The antibody to IL-1beta did not affect CRH-stimulated or PAF-stimulated PGE2 production or COX-2 expression. We conclude that CRH and PAF can induce the expression of IL-1beta, but this is not obligatory for increased PGE2 release, and the effect of these stimuli on COX-2 expression is a direct, IL-1beta-independent effect.

An inhibitor of type-1 cyclo-oxygenase in tissues from human pregnancy

BACKGROUND

Previous work has shown that first trimester human decidua contains a protein which directly inhibits the activity of type-1 cyclo-oxygenase (COX-1).

METHODS

Activity assays for cyclo-oxygenase types I and II were developed. Cell cytosol was prepared from a number of different sources: human placenta and decidua (first and third trimester), two placental cell-lines (BeWo and TCL-1), an endometrial stromal cell-line and K562 erythroleukemia cells. The effects of all cytosols on activity of type I cyclo-oxygenase, and of cytosols from BeWo choriocarcinoma and decidual cells on type II enzyme, were tested.

RESULTS

Cytosols from first trimester human placenta, two placental cell-lines, an endometrial stromal cell-line and K562 erythroleukemia cells all inhibited the type I enzyme. The inhibitor protein could not be detected in third trimester human decidual cells after labor, and was present only at very low levels in third trimester decidua prior to the onset of labor. Cytosols from BeWo and decidual cells had no effect on the activity of the type-2 cyclo-oxygenase enzyme.

CONCLUSIONS

The inhibitor of type I cyclo-oxygenase was not specific to pregnancy-related tissues, and may be a general regulator of this enzyme. Lower levels of inhibitor were present at term, but the physiological significance of this is unclear. The cytosolic inhibitor appears to be specific to the type I enzyme.

Corticotrophin-releasing hormone and platelet-activating factor induce transcription of the type-2 cyclo-oxygenase gene in human fetal membranes

Corticotrophin-releasing hormone (CRH) and platelet-activating factor (PAF) are considered to be involved in the physiological processes of human labour. Both may have dual effects, directly regulating myometrial contractility and fetal membrane prostaglandin production. During this study, we investigated the mechanisms through which CRH and PAF exert their latter effect. CRH and PAF increased prostaglandin production from intact fetal membrane discs, with a maximum stimulation after 8 h of culture. Reverse transcription-polymerase chain reaction (RT-PCR) analyses using primers specific for type-2 cyclo-oxygenase (COX-2) showed that CRH and PAF increased the transcription of COX-2 mRNA two-fold after 8 h culture. These data indicate that the increased fetal membrane prostaglandin production in response to CRH or PAF may involve the induction of COX-2.

Region and labour-dependent synthesis of prostaglandin E2 by human fetal membranes

To examine the effect of region and labour upon prostaglandin synthesis in human fetal membranes, intact membranes from three regions, the cervical region, the periplacental region and a region midway between the two, were collected following spontaneous labour and delivery or at elective caesarean section prior to labour. Discs of 2-cm diameter were cut from each of three regions and incubated for 1, 2, 4, 6, 12 or 24 h after which prostaglandin E2 concentration in the supernatant was measured. We found that there was an overall decrease in prostaglandin synthesis in tissues collected after labour, but that this effect could be reversed if exogenous arachidonic acid substrate was supplied. We found no differences in prostaglandin synthesis between tissues collected from each of the three regions. We conclude that prostaglandin synthesis from the fetal membranes during labour leads to depletion of arachidonic acid substrate and that regional changes in prostaglandin dehydrogenase activity do not appear to have a significant effect upon overall prostaglandin synthesis.

Regulation of prostaglandin production in intact fetal membranes by interleukin-1 and its receptor antagonist

There is strong evidence for the involvement of inflammatory mediators such as interleukin (IL)-1 in the biochemical mechanisms of parturition. Therefore the effects of the IL-1 family (IL-1alpha (1 ng/ml), IL-1beta (1 ng/ml) and the IL-1 receptor antagonist (IL-1ra) (10 ng/ml)) on the regulation of prostaglandin synthesis in term human fetal membranes were investigated. It was found that, after 4 h of culture, IL-1beta increased prostaglandin E2 (PGE2) output approximately twofold. This was associated with both a significant increase in cyclo-oxygenase-2 (COX-2) mRNA levels (approximately fourfold compared with control) and translocation of cytoplasmic phospholipase A2 (cPLA2) from the cytosol to the membrane fraction. IL-1alpha was less effective than IL-1beta at stimulating PGE2 production through similar mechanisms. IL-1ra had no effect on PGE2 output. However, in combination treatments, IL-1ra did not inhibit IL-1alpha- or IL-1beta-stimulated PGE2 output, and increased PGE2 production further compared with IL-1beta alone. IL-1ra decreased IL-1beta-induced COX-2 mRNA expression by about half and significantly increased cPLA2 protein levels, as detected by immunoblotting, when used alone and together with IL-1beta. These results suggest that IL-1ra has partial agonist properties when used together with IL-1alpha and IL-1beta in fetal membranes by increasing cPLA2 protein levels, which leads to an increase in the production of prostaglandins.

Interleukin-1beta and bacterial endotoxin change the metabolism of prostaglandins E2 and F2alpha in intact term fetal membranes

There is strong evidence that prostaglandins E2 and F2alpha (PGE2 and PGF2alpha) are involved in the initiation and maintenance of human parturition and that their production can be stimulated by a number of cytokines and in infection-induced preterm labour by bacterial endotoxin. This study used an intact fetal membrane disk model to investigate the regulation of PGE2 and PGF2alpha metabolism by interleukin-1 beta (IL-1beta) and bacterial endotoxin [lipopolysaccharide (LPS)]. Fetal membrane explants were incubated with IL-1beta (0.1 or 1.0 ng/ml) or LPS (10 ng/ml) for 24 h. A mixture of 3H-prostaglandin (0.1 microCi) and unlabelled prostaglandin (1 microg) was then added at selected times after the addition of inflammatory mediators. The radiolabelled prostaglandins and their metabolites were then extracted from the culture medium and quantified by high-pressure liquid chromatography. Levels of prostaglandin metabolites were generally decreased following incubation with IL-1beta or LPS, which is consistent with a decrease in the activity of 15-hydroxyprostaglandin dehydrogenase (PGDH). It is concluded that IL-1beta and LPS moderately decrease the metabolism of prostaglandins, which may contribute to increasing the local levels of active prostaglandins induced by these stimuli.

Stimulation of prostaglandin production from intact human fetal membranes by bacteria and bacterial products

The addition of live or sonicated Escherichia coli, or endotoxin from E. coli increased the release of prostaglandins (PG) on both sides of intact human fetal membranes after 24 h of incubation, indicating that live bacteria were not required to activate prostaglandin production. Time-course studies showed that the levels of PGE2 and PGF2alpha on the fetal side of the membrane were increased 6 h after the addition of endotoxin, whereas levels on the maternal side increased within 1-2 h. These changes were independent of the side to which the endotoxin was added, indicating that a stimulatory factor passes through the fetal membranes. This factor is not endotoxin, which did not cross the membranes, and further studies are required to identify this endogenous stimulus. Prostaglandin metabolite levels were either unaffected or increased by endotoxin, indicating that the main effect is at the level of increased prostaglandin biosynthesis rather than decreased metabolism.

A spontaneous induction of fetal membrane prostaglandin production precedes clinical labour

Fetal membranes from term human pregnancies produce prostaglandins, and may respond to bacterial endotoxin or interleukin-1 beta (IL-1 beta) with increased prostaglandin E2 (PGE2) production. The effects of endotoxin persisted for up to 24 h, whereas those of IL-1 beta were maximal 4-8 h after addition. The maximum levels of PGE2 (200-350 pg/ml) were similar in all experiments, and were independent of the stimulus used. Not all tissues responded to these stimuli; those which did not had basal levels of PGE2 production of 200-350 pg/ml, which was not further increased by endotoxin or IL-1 beta. The basal production from these tissues was therefore similar to the maximal production from those tissues which responded to endotoxin or IL-1 beta. The high basal production of PGE2 was attributed to prior in vivo activation of the membranes such that PGE2 synthesis could not be further stimulated in vitro. Overnight pretreatment with aspirin decreased basal PGE2 production from these activated membranes to < 100 pg/ml/4 h during subsequent culture in aspirin-free medium. Both endotoxin and IL-1 beta increased PGE2 production from the activated aspirin-pretreated membranes during this culture time, but this was transient as after 12 h of culture basal PGE2 production rose to over 200 pg/ml despite aspirin pretreatment.

Titration of antiplatelet treatment in pregnant women at risk of preeclampsia

We recruited 111 patients who were considered to be at significantly increased risk of preeclampsia on the basis of previous obstetric history or preexisting medical disorders. All patients were treated with low dose aspirin (75 mg/day) from the first occasion the patient attended the antenatal clinic, regardless of gestational age. If the maternal mean platelet volume (MPV) increased significantly (by > 0.8 fl) from the baseline, antiplatelet treatment was increased. Five pregnancies were lost during the second trimester and 106 of the treated patients had live infants. The incidence of neonatal death (3/106 infants) was much lower than in the previous pregnancies in these patients (32/134 infants). Patients who were treated from the first trimester of pregnancy (group A, 89 patients) did substantially better than those treated from the second trimester (group B, 17 patients) as assessed by the incidence of pre-eclampsia or intrauterine growth restriction (IUGR), gestational age and birthweight at delivery. These data suggest that longitudinal monitoring of the MPV may identify the women who could benefit from increased antiplatelet treatment, and that antiplatelet treatment may be more effective when initiated in the first trimester rather than later in pregnancy.

The regulation of platelet aggregation in vitro by interleukin-1beta and tumor necrosis factor-alpha: changes in pregnancy and in pre-eclampsia

Platelet activation occurs in early pregnancy in women at risk of developing pre-eclampsia. Cytokines have been implicated in the pathogenesis of pre-eclampsia, so we determined the effects of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) on the in vitro aggregation of human platelets. IL-1beta increased aggregation of platelets from non-pregnant and pre-eclamptic women, and inhibited the aggregation of platelets from normal pregnant women. This latter effect was linked to a diminished P-selectin expression on ADP-stimulated whole blood platelets in normal pregnant women (p = 0.011). Platelet aggregation in response to ADP was found to be inhibited after preincubation with TNF-alpha in non-pregnant (38%, p = 0.01) and in normal pregnant women (54%, p = 0.001) and not affected in pre-eclamptic women. The inhibitory effects of TNF-alpha were mediated through the P75 receptor for TNF-alpha.

The regulation of progesterone and hCG production from placental cells by interleukin-1beta

We have investigated the roles of interleukin-1beta as a regulator of progesterone and chorionic gonadotrophin production from human placental cells. In primary placental cells IL-1beta increased hCG synthesis through a cyclic AMP-independent pathway, and was without effect on progesterone or cyclic AMP production. Since dibutyryl cyclic AMP increased progesterone production, this suggests that there is no coupling between the IL-1beta receptor and the adenylate cyclase enzyme in these cells. Immortalised trophoblast cells responded to IL-1beta by increasing progesterone production through a cyclic AMP-dependent mechanism, but hCG production by these cells was unaffected by IL-1beta or dibutyryl cyclic AMP. Further studies are needed to identify the role of IL-1beta as a possible regulator of progesterone production in primary placental cells. While hCG production in first-trimester trophoblast was increased by dibutyryl cyclic AMP and IL-1beta, both these effects may involve other factors such as IL-6, and their second messenger systems.

Second messengers and the control of progesterone production from first trimester trophoblast

Basal progesterone production from first trimester placental cells in culture was high during the first 24 h of culture and fell to less than 30% of the initial level after 96 h in vitro. 22(R)-Hydroxycholesterol had a similar effect on progesterone production at all incubation times, indicating that the decline in basal steroidogenesis was not due to a loss of mitochondrial or post-mitochondrial enzymes. Continuous stimulation with dibutyryl (db) cyclic AMP maintained progesterone synthesis at a relatively constant high level despite the fall in basal progesterone production, and the optimum concentration of db cyclic AMP was 1.0 mM. The calcium ionophore A23187 had no effect on progesterone incubation during short-term cultures (<4 h), and inhibited steroidogenesis after 24 h. Repeated addition of A23187 during 96 h of culture also inhibited progesterone production. These findings indicate that progesterone production in human trophoblast is supported by a local factor which maintains a high level of steroid production through a cyclic AMP-dependent mechanism. The inhibitory effects of calcium ionophore in trophoblast differ from the stimulatory effects of this compound in other steroidogenic cells, but the reasons for the difference are not known at present.

A comparison of cytokine and hormone production by decidual cells and tissue explants

Previous work has shown that enzymatic digestion of human placental tissue can induce the production of the cytokine interleukin-1 beta. Most studies of the feto-maternal interface of human pregnancy have used decidual cells prepared in a similar way, but the effects of tissue dissociation on the production of growth factors, cytokines, prostaglandins or hormones have not been investigated. Our studies show human decidual explants produce substantially lower levels of a range of factors than do human decidual cells cultured under the same conditions, indicating that induction may be a general process during the dissociation of tissues in vitro as the production of interleukins-1 beta, -6 and -8, granulocyte-macrophage colony-stimulating factor, transforming growth factor-beta 2, tissue necrosis factor-alpha, prostaglandins E2 and F2 alpha, and prolactin were all affected. The induction of cytokine production (expressed per mg tissue protein) ranged from 10- to 300-fold, indicating that isolated cells cultured in vitro may not reflect accurately the in vivo situation.

Partial characterization of an immortalized human trophoblast cell-line, TCL-1, which possesses a CSF-1 autocrine loop

Many previous studies in both mouse and human placenta have implicated a role for colony stimulating factor-1 (CSF-1) in the regulation of placental development. In this study we have examined CSF-1 production by an immortalized cell line (TCL-1) derived from the choriodecidua, transfected with a retrovirus gene coding for the large-T antigen. TCL-1 cells were uniformly positive by immunocytochemistry for the composite sub-units of human chorionic g gonadotrophin (hCG) but were negative for markers of other cell types localized at the fetal-maternal interface. Gelatinase enzymes were secreted by TCL-1 cells cultured on extracellular matrix in a manner indicative of extra-villous trophoblast. Dot-blot immunoassays and ELISA indicated that CSF-1 was secreted by TCL-1 cells, at levels comparable to primary trophoblast cells and BeWo choriocarcinoma (trophoblast tumour) cells. Reverse transcriptase-polymerase chain reaction analysis confirmed the presence in TCL-1 cells of CSF-1 receptor mRNA (c-fms gene product), indicating that the components of a potential autocrine loop were present in these cells. Proliferation of TCL-1 cells was not affected by the addition of exogenous CSF-1 but was elevated in response to treatment with a CSF-1 neutralizing antibody. The immortalized cell line, TCL-1, provides a potential model in which to investigate regulation of growth and differentiation of trophoblast cells in vitro.

Preparation of a population of macrophages from human third trimester decidua

Human decidua in the third trimester of pregnancy contains at least four different cell types (stromal cells, macrophages, T-lymphocytes and granulocytes). The contributions of these cells to the overall function of the tissue are not known, although it is anticipated that both stromal cells and macrophages will produce the prostaglandins involved in labour. In addition, the decidua produces cytokines, but the cellular source has not been identified. As a first stage to addressing these questions, we have developed magnetic separation methods to obtain enriched populations of decidual macrophages which contain at least 5 x 10(6) cells. We found that a preparation of up to 10(7) cells which are up to 80% pure (as assessed by a fluorescence-activated cell sorting procedure) and approximately 90% pure (as assessed by immunocytochemistry) can be obtained reliably with this method. These cells are viable for at least 48 h in culture after the enrichment procedure, and produce prostaglandins after stimulation with interleukin-1 beta.

Morphological interactions of human first trimester placental villi co-cultured with decidual explants

Abnormalities of pregnancy such as pre-eclampsia and intrauterine growth retardation are characterized by shallow trophoblastic invasion of the placental bed, the precise molecular pathophysiology of which remains to be fully elucidated. An in-vitro model involving a co-culture of first trimester placental villi and decidua parietalis explants (of 8-12 weeks gestation) was developed and used to characterize the migration and local invasion of trophoblast cells. Trophoblast proliferation (confirmed by Ki-67 immunostaining), differentiation and loose attachment of placental villi to the underlying decidual epithelium or stroma occurred within the first 24 h of co-culture. This was followed by erosion of the syncytial layer of the placental villi and commencement of a progressive cytotrophoblast invasion after 48 h of co-culture, which continued until 120 h, when the experiments were terminated. E-cadherin was expressed at the interfaces between trophoblast cells within the villi, but expression of this adhesion molecule seemed to be down-regulated in the invasive trophoblast cells. Our results suggest that the model could be useful in investigating the factors that control early human placentation and the feto-maternal interface.

Nitric oxide synthase in human placenta and umbilical cord from normal, intrauterine growth-retarded and pre-eclamptic pregnancies

1. It has been suggested that a deficiency of nitric oxide (NO) may explain many of the pathophysiological features of pre-eclampsia (PE) and intra-uterine (foetal) growth retardation (IUGR). To elucidate further the role of NO in the pathophysiology of pregnancy we have determined the relative amount and activity of NO synthase (NOS) in first trimester and normal-term placental tissues, as well as in the placenta and umbilical cord in pregnancies complicated by PE and IUGR, using NG-nitro-L-[2,3,4,5(-3)H]-arginine ([3H]-L-NOARG) binding, quantitative in vitro autoradiography, [3H]-arginine to [3H]-citrulline conversion and Western blotting. 2. Specific, high affinity (KD = 38 nM) [3H]-L-NOARG binding was demonstrated in the villous trophoblast of normal-term placentae. Binding was calcium-independent, stereoselective and exhibited a rank order of inhibition by NOS inhibitors and substrate (L-NOARG > or = L-NMMA > or = 7-NI > L-NAME > L-Arg > or = L-NIO > ADMA). 3. [3H]-L-NOARG binding density and NOS activity were both significantly greater in placental tissues from first trimester and PE or IUGR complicated pregnancies compared to normal-term placentae. 4. Western blotting, using an endothelial NOS peptide antiserum, demonstrated a approximately 140 KDa protein band in placental extracts and indicated that the amount of immunoreactive material was significantly greater in first trimester compared to normal-term placentae. 5. Specific [3H]-L-NOARG binding was also localized to the endothelial lining of umbilical arteries and veins, binding density being greater in the artery than the vein. [3H]-L-NOARG binding to the umbilical artery endothelium was significantly lower in PE and IUGR complicated pregnancies compared to normal-term controls. 6. The role of trophoblast-derived NO in human placental pathophysiology remains to be established, but differences in the amount of placental [3H]-L-NOARG binding, NOS activity and immunoreactive material indicate that expression of NOS in the villous trophoblast falls during pregnancy. Conversely, the apparent reduction in NOS in the umbilical artery endothelium in PE and IUGR complicated pregnancies may be indicative of endothelial dysfunction.

Interleukin-1 beta independently stimulates production of prostaglandin E2 and cyclic AMP from human decidual cells

Interleukin-1 beta (IL-1 beta) increased the production of cyclic AMP and prostaglandin E2 (PGE2) by cultured human decidual cells during 24 h of stimulation, but not over short incubation times (< 6 h). At concentrations of IL-1 beta ranging from 1 to 100 pg/ml, there were parallel changes in cyclic AMP and PGE2 levels, but 1000 pg of IL-1 beta/ml inhibited cyclic AMP production while still stimulating PGE2 synthesis. The possible link between cyclic AMP and PGE2 was therefore studied further. Inhibition of IL-1 beta-stimulated PGE2 synthesis by indomethacin and direct addition of PGE2 had no effect on cyclic AMP levels, indicating that PGE2 did not increase cyclic AMP production by human decidual cells and confirming the independent synthesis of cyclic AMP and PGE2. The increase in cyclic AMP production induced by IL-1 beta is dependent on protein synthesis, but it is not known which component of the adenylate cyclase is increased. A phosphodiesterase inhibitor potentiated the effects of IL-1 beta on cyclic AMP synthesis, indicating that the cytokine may increase cyclic AMP metabolism. We suggest that high concentrations of IL-1 beta activate phosphodiesterase activity more than adenylate cyclase, which gives rise to the low levels of cyclic AMP noted above. IL-1 beta also decreased forskolin-stimulated cyclic AMP production, which again indicates increased cyclic AMP metabolism. Since most concentrations of IL-1 beta alone increased cyclic AMP levels, this stimulation must out-weigh the increase in metabolism apparent in the presence of forskolin, phosphodiesterase inhibitor or high levels of interleukin. It is clear that IL-1 beta increased decidual PGE2 production independently of cyclic AMP, and that other second messenger must mediate the action of this cytokine.

Endothelin-1 regulates human decidual cells through both A- and B-type receptors

The aims of this study were to investigate the effects of endothelin-1 (ET-1) on first trimester human decidual cells, identify the ET receptor sub-types through which these effects are mediated and assess the role of cyclic AMP in any effects of ET-1. ET-1 increased prostaglandin production by first trimester decidual cells, which was consistent with similar studies in third trimester decidual cells. The endothelin A-type receptor (ETA) was coupled to the increased prostaglandin production from first trimester cells, as shown by the inhibitory effects of BQ610, an ETA receptor antagonist. The time course of this effect was unusual, with a rapid increase peaking after 6 h of stimulation, followed by a longer effect over 12-24 h, which was paralleled by changes in cyclic AMP production. No evidence was obtained for any involvement of cyclic AMP in mediating the effects of ET-1 on prostaglandin production. ET-1 also increased decidual prolactin production with a maximum effect after 6 h of stimulation. This was mediated through the ETB receptor and may be linked to increased cyclic AMP production, indicating that the ETA and ETB receptors were coupled to different second messenger systems and affected decidual cell function in different ways.

Formation and metabolism of 14,15-epoxyeicosatrienoic acid by human reproductive tissues

Human granulosa-luteal cells cultured in the presence of arachidonic acid produced low levels of the epoxygenase metabolite 14,15-epoxy-5,8,11-(Z,Z,Z)-eicosatrienoic acid (14,15-EpETrE) as determined by HPLC analysis and gas chromatography mass spectrometry. When authentic 14,15-[3H]EpETrE was incubated with these cells in the absence of serum it was metabolised initially to the dihydroxy derivative (14,15-dihydroxy-5,8,11-eicosatrienoic acid, 14,15-DiHETrE) and subsequently to a number of more polar metabolites as determined by HPLC. Fetal calf serum protected 14,15-EpETrE from metabolism for at least 2 h. A similar pattern of metabolism was obtained when 14,15-[3H]EpETrE was incubated with a human choriocarcinoma cell line (BeWo). Microsomes from this cell line converted arachidonic acid to a large number of radioactive metabolites including 14,15-DiHETrE and 11,12-DiHETrE although there was no evidence for the parent epoxides. These results extend earlier findings that human reproductive tissues produce epoxygenase metabolites, and demonstrate the rapid metabolism of these compounds by intact cells in the absence of serum.

Decidual adenylate cyclase and prostaglandin production in vitro

Human decidua contains an active adenylate cyclase, and a number of studies indicate that adenylate cyclase is functionally linked to increased in vitro prostaglandin synthesis. Increased decidual prostaglandin synthesis is associated with parturition, and therefore activation of adenylate cyclase may be involved in the control of human parturition. In this study, third trimester human decidual cells were preincubated for no more than 24 h prior to stimulation with a number of reagents which increase cellular cyclic AMP levels. Forskolin rapidly increased intracellular and extracellular cyclic AMP levels, but there was no increase in prostaglandin E2 biosynthesis during incubations ranging from 5 min up to 24 h. Dibutyryl cyclic AMP or 8-bromo-cyclic AMP were also without effect on PGE2 production, which suggests that the adenylate cyclase was not linked to the mechanisms regulating prostaglandin production. Cholera toxin increased basal cyclic AMP and PGE2 synthesis, and was without effect on IL-1 beta-stimulated PGE2 levels. PGE2 synthesis was increased by 24 h culture with IL-1 beta in all the cell preparations, indicating that the cells were biologically active, and that the lack of effect of changes in cyclic AMP synthesis on PGE2 levels could not be attributed to a defect in the prostaglandin synthetic pathway. Our findings did not agree with earlier work which showed that changes in cyclic AMP were correlated with changes in PGE2 production by human decidual cells. It is clear that in the previous studies the decidual cells were preincubated for 4-7 days prior to stimulation, in contrast with 24 h in our investigation.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-1 beta-stimulated prostaglandin synthesis by human decidual cells is independent of protein kinase C

Basal prostaglandin E2 (PGE2) synthesis by human decidual cells was stimulated by phorbol myristate acetate (PMA) which activates protein kinase C. Staurosporine, which is an inhibitor of protein kinase C in most systems, also increased basal PGE2 synthesis. Further work is needed to explain this finding, as another inhibitor of protein kinase C, H7, inhibited PGE2 production under similar culture conditions. Interleukin-1 beta (IL-1 beta)-stimulated PGE2 synthesis was potentiated by coincubation with PMA or staurosporine, indicating that IL-1 beta and protein kinase C increase decidual PGE2 synthesis through different mechanisms. Desensitization of the decidual cells for 24 h with PMA did not affect IL-1 beta-stimulated PGE2 synthesis. The complex roles of protein kinase C in regulating decidual prostaglandin synthesis require further investigation, but it is clear that the effects of IL-1 beta are not mediated by protein kinase C.

Treatment of pseudomyxoma peritonei in a geriatric patient population

Pseudomyxoma peritonei of appendiceal origin is a disease characterized by the progressive accumulation of mucus ascites within the abdomen and pelvis. Metastatic disease outside the peritoneal cavity is unusual. Gastrointestinal function is lost from external compression of stomach, small bowel, and large bowel. New surgical and regional chemotherapy treatments were used to provide palliation of two patients aged 88 and 85 years. The selection criteria and methodologies for treatment of geriatric patients with pseudomyxoma peritonei are presented.

Interleukin-1 beta-stimulated PGE2 production from early first trimester human decidual cells is inhibited by dexamethasone and progesterone

Cytokines are known to increase the production of prostaglandins by human decidual cells, but negative regulators have not been identified. We have examined the effects of dexamethasone and progesterone on prostaglandin (PG) E2 synthesis by cultured human first trimester decidual cells. The numbers of cyclooxygenase (COX) enzyme positive cells were visualised by immunocytochemistry, using antibodies specific for COX-1 and COX-2. Interleukin-1 beta stimulated the production of prostaglandins E2 and F2 alpha dose-dependently, and this was associated with increased numbers of COX-2 positive cells. Progesterone (10(-7)-10(-6) M) and dexamethasone (10(-7)-10(-6) M) inhibited basal and interleukin-1 beta-stimulated prostaglandin production, and decreased the numbers of COX-2 positive cells. Neither interleukin-1 beta nor the steroids affected numbers of COX-1 positive cells. COX-2 seems to be the main enzyme controlling the synthesis of PGE2 by human decidual cells, and may be negatively regulated by progesterone.

Angiotensin II (AT1) vascular binding sites in human placentae from normal-term, preeclamptic and growth retarded pregnancies

Angiotensin II (ANG II) is a potent vasoconstrictor in isolated human placental cotyledons and may contribute to the regulation of fetoplacental perfusion. We have used quantitative in vitro receptor autoradiography to examine antagonist ((Sar1,Ile8)-[125I]ANG II) and agonist ligand ([125I]ANG II) binding sites in normal-term, preeclamptic and fetal (intrauterine) growth retarded pregnancies. A similar distribution of binding sites was demonstrated using both ligands, localized to blood vessels in placental villi. Binding density was inversely related to vessel size, being significantly greater on microvessels in distal regions of the villous tree than on proximal vessels in main stem villi. Binding sites exhibited the characteristics of the AT1 class of ANG II receptor, ligand binding being sensitive to dithiothreitol, completely inhibited by nonpeptide AT1 antagonists (Losartan, EXP3174 and SKF108566) and not inhibited by the AT2 antagonist (PD123319). Guanine nucleotides also inhibited [125I]ANG II binding and abolished the high affinity component of agonist inhibition of (Ser1,Ile8)-[125I]ANG II binding, indicating G protein coupling. The capacity and affinity of the binding sites were significantly lower in placentae from pregnancies complicated by preeclampsia and intrauterine growth retardation compared to that in normal-term controls. These differences were apparently not due to prior receptor occupancy by endogenous ligand, but may reflect activation of the placental renin-angiotensin system and receptor down-regulation. Locally generated ANG II, acting via AT1 receptors, may contribute to the regulation of fetoplacental blood flow and influence placental perfusion in preeclamptic and growth retarded pregnancies.