Colorectal resection via natural orifice specimen extraction versus conventional laparoscopic extraction: a meta-analysis with meta-regression.

BACKGROUND: Studies have shown differences in postoperative outcomes between two minimally invasive extraction methods for colorectal lesions-natural orifice specimen extraction surgery (NOSES) and conventional laparoscopic surgery (CLS). The aim of this study was to discover the major differences in NOSES and CLS to refine current practice. METHODS: Electronic databases were searched for articles comparing NOSES and CLS from inception till March 2020. Weighted mean differences (WMD) and odds ratio (OR) were estimated for continuous and dichotomous outcomes, respectively. Summary statistics were calculated using the DerSimonian and Laird random effects. RESULTS: Twenty-one studies (15 on malignant disease, 4 on benign disease, 2 on both) were included in this meta-analysis, totalling 2378 patients (1079 NOSE, 1299 CLS). NOSE was associated with decreased: intraoperative bleeding (WMD: - 10.652 ml; 95% CI: - 18.818 ml to - 2.482 ml; p < 0.001), pain score (WMD: - 1.520; 95% CI - 1.965 to - 1.076; p < 0.001), time to flatus (WMD: - 0.306 days; 95% CI: - 0.526 to - 0.085 days; p < 0.001), length of hospital stay (WMD: - 1.048 days; 95% CI: - 1.488 to - 0.609 days; p < 0.001), and total morbidity (OR: 0.548; 95% CI: 0.387 to 0.777; p = 0.001). Subgroup analyses showed significant differences between malignant and benign lesions for intraoperative bleeding (p = 0.011) and pain score (p = 0.010). Meta-regression analyses showed an association between the American Society of Anaesthesiologists (ASA) physical status classification III with pain (p = 0.03) and ASA III with time to flatus (p = 0.04). CONCLUSIONS: This meta-analysis and meta-regression demonstrated that NOSES had better postoperative outcomes compared to CLS. More comprehensive reviews should be conducted on the long-term outcomes specific to the extraction site to better inform clinical practice.

[Prognostic value of Montreal Cognitive Assessment in heart failure patients].

Objective: To explore the occurrence of cognitive impairment in Chinese heart failure (HF) patients and it's impact on prognosis. Methods: In this prospective observational study, a total of 990 HF patients were enrolled from 24 hospitals in China during December 2012 to November 2014. All patients were administrated with the interview-format Montreal Cognitive Assessment (MoCA), according to which they were divided into MoCA<26 (with cognitive impairment) group and MoCA≥26 (without cognitive impairment) group. Baseline data were collected and a 1-year follow up was carried out. Univariate and multivariate logistic or Cox regression were performed for 1-year outcomes. Results: Cognitive impairment was evidenced in 628 patients (63.4%) and they were more likely to be older, female, and with higher proportion of New York Heart Association(NYHA) class Ⅲ-Ⅳ, chronic obstructive pulmonary disease (COPD), ischemic heart disease, while body mass index (BMI), education level, and medical insurance rate were lower (all P<0.05) as compared to patients in MoCA≥26 group. The rate of percutaneous intervention, device implantation, cardiac surgery and evidence-based medications were significantly lower in MoCA<26 group than in MoCA≥26 group (all P<0.05). During the 1-year follow up, patients in the MoCA<26 group had higher all-cause mortality (10.2%(64/628) vs. 2.2%(8/362), P<0.01), cardiovascular mortality (5.9%(37/628) vs. 0.8%(3/362), P<0.01) and major adverse cardiac and cerebrovascular events (MACCE) (9.6%(60/628) vs. 2.5%(8/362), P<0.01) than patients in the MoCA≥26 group. In univariate regression, MoCA<26 was associated with increased all-cause mortality (HR(95%CI):4.739(2.272-9.885), P<0.01), cardiovascular mortality (HR(95%CI):7.258(2.237-23.548), P=0.001) and MACCE (OR(95%CI):4.143(2.031-8.453), P<0.01). After adjustment by multivariate regression, MoCA<26 was indicated as an independent risk factor for all-cause mortality (HR(95%CI): 6.387(2.533-16.104), P<0.01), cardiovascular mortality (HR(95%CI): 10.848(2.586-45.506), P=0.001) and MACCE (OR(95%CI): 4.081(1.299-12.816), P=0.016), while not for re-hospitalization for HF (OR(95%CI):1.010(0.700-1.457), P=0.957). Conclusions: Cognitive impairment is common in HF patients,and it is an independent prognostic factor for 1-year outcomes. Routine cognitive function assessment and active intervention are thus recommended for HF patients.

[Dabigatran versus warfarin for the prevention of stroke in Chinese patients with nonvalvular atrial fibrillation: Chinese subpopulation analysis of RE-LY].

Objective: This analysis was performed to evaluate the efficacy in stroke prevention and safety of dabigatran in Chinese nonvalvular atrial fibrillation(NVAF) patients enrolled in RE-LY trial. Methods: RE-LY was an prospective, open-label, randomized, multicenter study. From March 2006 to March 2009, 541 atrial fibrillation patients at risk of stroke were recruited from 13 medical centers in China. Patients randomly received, in a blinded fashion, fixed doses of dabigatran-110 mg or 150 mg twice daily or, in an unblinded fashion, adjusted-dose warfarin. The primary efficacy endpoint was stroke or systemic embolism. The primary safety endpoint was major bleeding. Results: The incidence of stroke in the Chinese subpopulation was 1.94% per year(7 cases) in the group that received 110 mg of dabigatran (dabigatran 110) and 1.10% per year(4 cases) in the group that received 150 mg of dabigatran (dabigatran 150), as compared with 2.87% per year (10 cases) in warfarin group . Incidence of ischemic stroke was 1.11% per year(4 patients) in dabigatran 110 group, 0.82% per year(3 cases) in dabigatran 150 group and 2.01% per year(7 patients) in warfarin group. Incidence of hemorrhagic stroke was 0.28% per year(1 case) in dabigatran 110 group, 0.27% per year(1 case) in dabigatran 150 group and 0.57% per year(2 cases) in warfarin group. All-cause mortality was similar among the three treatment groups: 3.33% per year(12 cases) in dabigatran 110, 2.19% per year(8 cases) in dabigatran 150 and 2.58% per year(9 cases) in warfarin group. Incidence of major bleeding event was 0.56% per year(2 cases) in both dabigatran groups, as compared with 1.43% per year(5 cases) in warfarin group. Gastrointestinal disorders such as dyspepsia occurred in 12.8% patients of both dabigatran groups, and in 5.6% patients of warfarin group. Conclusions: Despite the descriptive statistical analysis in nature of present study due to the limited number of subjects, our subgroup analysis implies that like warfarin, dabigatran is efficacious and safe for thromboembolism prevention in Chinese patients with atrial fibrillation at risk of stroke. Clinical Trail Registry National Institutes of Health(http: //www.clinicaltrials.gov), CT00262600.

Haemoglobin A(1c) , acute hyperglycaemia and short-term prognosis in patients without diabetes following acute ST-segment elevation myocardial infarction.

AIMS: To assess the prognostic impact of HbA(1c) and blood glucose level in patients with acute ST-segment elevation myocardial infarction and without diabetes. The relationship between HbA(1c) and acute hyperglycaemia was also explored. METHODS AND RESULTS: We evaluated 4793 ST-segment elevation myocardial infarction patients with baseline HbA(1c) and three glucose measurements in the first 24 h. First, patients were stratified into quintiles by HbA(1c) and mean/admission glucose level. A total of 373 deaths (7.8%) occurred at 7 days, and 486 deaths (10.1%) occurred at 30 days. There were no significant differences in 7- and 30-day mortality, and major adverse cardiovascular event rates across HbA(1c) quintiles (< 34.4 mmol/mol (5.3% ), 34.4 to < 37.7 mmol/mol (5.6%), 37.7 to < 41.0 mmol/mol (5.9% ), 41.0 to < 47.5 mmol/mol (6.5%), and ≥ 47.5 mmol/mol; P for trend > 0.05). The risks of mortality and major adverse cardiovascular events were significantly increased in patients with higher glucose quintiles and lower quintile compared with the middle quintile after multivariable adjustment (P < 0.001). Patients were then reclassified into four groups according to mean/admission glucose and HbA(1c) levels. The group with elevated glucose and non-elevated HbA(1c) was associated with the highest mortality and major adverse cardiovascular event risk (P < 0.001). CONCLUSIONS: Unlike acute hyperglycaemia, an elevated HbA(1c) level was not a risk factor for short-term outcomes in ST-segment elevation myocardial infarction patients without diabetes. Patients with acute hyperglycaemia and non-elevated HbA(1c) were associated with the worst prognosis. That suggests chronic glycaemic control/HbA(1c) level may help to recognize stress-induced hyperglycaemia and identify high-risk patients.

Development of a new model of transvenous thrombosis in the pig superior sagittal sinus using thrombin injection and balloon occlusion.

PURPOSE: To establish an experimental model of superior sagittal sinus (SSS) thrombosis using a transvenous route, and thrombin and balloon occlusion, in pigs. METHODS: The SSS was catheterized transvenously in six pigs. Thrombin was injected into the pigs' SSS to induce thrombosis. Magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) confirmed successful SSS thrombosis. MRI and MRV were also used to observe the evolution of thrombus and accompanying brain parenchymal changes before thrombus induction postoperatively on Days 1, 3, and 7. The pigs were sacrificed for histological examination at the follow-up. RESULTS: SSS thrombosis was successfully achieved in all six pigs. On Day 1 postoperatively, MRV confirmed SSS thrombosis and MRI revealed brain edema in each animal. On Day 3, venous infarction was noted in two cases, one of which appeared to be hemorrhagic. On Day 7, MRV showed partial recanalization of the SSS in one pig. Brain edema was significantly relieved in four cases while, in two other cases, the extent of venous infarction was reduced. Histological examination confirmed SSS thrombosis in all animals, with recanalization in only one case. In two of the animals, bilateral parasagittal infarction was seen, including one with petechial hemorrhage. In the other four animals, bilateral parasagittal edema was observed. CONCLUSION: The development of an experimental model of SSS via the transvenous route is feasible in pigs using thrombin and balloon occlusion. This model closely resembles SSS thrombosis in humans, and can be applied in the clinical study of this phenomenon as well as in clinical therapeutic applications.

[An outbreak of acute gastroenteritis caused by Sapovirus in a community of Guangdong province].

Objective: To investigate the epidemiological characteristics and clinic symptoms of an outbreak of infectious diarrhea caused by Sapovirus, in CT community, Zhaoqing, Guangdong province. Methods: Retrospective study of field epidemiology investigation was carried out and Chi-square test was used enteroviruses were detected by RT-PCR in swab, fecal specimens and water samples. Results: A total of 422 cases were identified in this outbreak, with the prevalence as 11.95%. Cases mainly concentrated between 21 and 24, December, with curves noticed by point- source and peaked on the 22(nd). Symptoms mainly appeared as vomiting, with watery stool. Patients were founded in every village, with the highest prevalence appeared in the elderly (25.20%) but involved in every age group. Sapovirus infection was most frequently seen in the population under 25 years of age, with overall prevalence as 16.41%. People older than 50 years of age took the second place (12.05%), and the lowest was seen between 25 to 49 years age group (8.42%). Sapovirus was detected in both swab and fecal specimens, with the positive rate as 38.78%. Both general and heat- resistant coliformed-bacteria were detected in the 24 monitored water samples, with the qualification rates as 95.83%, 45.83% and 50.00%, respectively. However, Sapovirus was not detected in any of the water samples. Conclusions: Our findings confirmed that an outbreak, caused by sapovirus infection in CT community was most likely related to the central water supply. The surveillance system for infectious diarrheal diseases should be improved and both public health awareness and surveillance programs on drinking water should be strengthened.

Clinical characteristics of acute ischemic syndrome in China.

OBJECTIVE: To analyse the characteristics and therapies of patients with acute ischemic syndrome in China. METHODS: This study is part of the international multicentre registry for acute ischemic syndrome. Since April 1999, the data of patients admitted to designated hospitals with acute ischemic cardiac chest pain were collected by filling in Case Report Forms offered by the Canadian Cardiovascular Collaboration. The main clinica l characteristics and in hospital events of the patients were recorded. RESULTS: Fifteen hundred and nine cases of acute ischemic syndrome from 34 hospitals nationwide were enrolled in the registry (including unstable angina and non Q-wave myocardial infarction). The mean age of the patients was 62.3. Male dominance (62.2%) was noted. The percentages of patients with chest pain at presentation and abnormal ECG were 47.8% and 89.5%, respectively. The most common clinical diagnosis on admission was unstable angina, accounting for 91.3% of the patients and non Q-wave myocardial infarction (MI), accounting for the other 8.7%. During hospitalization, the following interventions were given: thrombolytic therapy in 50 cases (3.3%), coronary angiography in 528 cases (35.0%), percutaneous transluminal coronary angioplasty (PTCA) in 253 cases (16.8%) and coronary artery bypass graft surgery (CABG) in 62 cases (4.1%). Nitrate (oral or patch ) and anti-platelet therapy were used in 1460 cases (96.8%) and 1441 cases (95.5%), respectively. The incidence of in hospital major events was 18.8%, in cluding 18 deaths (1.2%), with the most common causes being severe arrhythmias and sudden death. CONCLUSIONS: Patients with acute ischemic syndrome in China have mostly been diagnosed as cases of unstable angina. A relatively high PTCA rate but low CABG rate was noted in China. The most common cause of in hospital death is severe arrhythmias or sudden death.

[Tentative study of geographical epidemiology of schistosomiasis japonica in Yunnan province].

Schistosomiasis prevails in 17 counties and cities in Yunnan Province. Approximately, a population of 301,511 were affected and the snail-ridden area amounted to 219,000,000m2 in the past years. These endemic areas were not evenly distributed, but rather scattered. The endemic foci were vertically distributed at an altitude of 1,350-2,450 metres above sea level. Human cases were found mostly in areas with an elevation of greater than or equal to 1,800 metres, and became progressively fewer with the ascent. However, in areas with an-elevation of less than or equal to 1800 metres, the infection rate in the inhabitants decreased with the descent. In areas with an average temperature of 11.8-19.5 degrees C and the annual rainfall up to 574-970mm, transmission of the schistosomiasis was always present, suggesting an annual mean temperature around 15.7 degrees C and rainfall 800-900mm were favourable factors for schistosomiasis transmission. The cultivated areas with paddy soils were most suitable for the breeding of Oncomelania snails, where schistosmiasis was severely prevalent. Only a few Oncomelania snails and patients were observed in areas covered with red loam. No patient or snail was found in areas with brown loam or mountain meadow soil.

Complex hemodynamic insult in combination with wall degeneration at the apex of an arterial bifurcation contributes to generation of nascent aneurysms in a canine model.

BACKGROUND AND PURPOSE: The detailed mechanisms of cerebral aneurysm generation remain unclear. Our aim was to investigate whether specific hemodynamic insult in combination with arterial wall degeneration leads to the development of aneurysms in a canine model. MATERIALS AND METHODS: New branch points in the common carotid artery were created in 18 dogs. Nine animals subsequently received elastase insult at the arterial bifurcation apex (elastase-treated bifurcation group); the control bifurcation group (n=9) received saline, and 3 dogs received an elastase insult to both straight common carotid arteries (elastase-treated straight group). Angiographic and hemodynamic analysis was performed immediately and 12 and 24 weeks' postsurgery; histologic response was evaluated at 12 and 24 weeks. RESULTS: Angiography revealed nascent aneurysms (mean, 3.2±0.4 mm) at the arterial bifurcation apices in 5/9 models of the elastase-treated bifurcation group (versus 0 in the control bifurcation group and elastase-treated straight group) without any observed aneurysm rupture. Histologic analysis revealed internal elastic lamina discontinuity, elastic fiber disruption, a thinner muscular layer, reduced smooth-muscle cell proliferation, increased inflammatory cell (macrophage) infiltration, and expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 in the media of the elastase-treated bifurcation group compared with that in either the control bifurcation group or the elastase-treated straight group (P<.001). Hemodynamic analysis after surgery indicated that the apex experienced extremely low wall shear stress and flow velocity and the highest relative and total pressure in the elastase-treated bifurcation group, while the values returned to normal after arterial wall remodelling. CONCLUSIONS: In our study, combined hemodynamic insult and arterial wall degeneration at arterial bifurcations are required for the generation of aneurysms in a canine model.

Anaemia and prognosis in acute coronary syndromes: a systematic review and meta-analysis.

OBJECTIVE: This meta-analysis was conducted to summarize the association between anaemia and outcomes in patients with acute coronary syndromes (ACS). METHODS: MEDLINE®, Cochrane Library, OVID and EMBASE databases were searched to identify studies that examined the effect of anaemia on mortality or other adverse events (heart failure, cardiogenic shock or major bleeding). RESULTS: Nineteen studies met the final inclusion criteria (total number of patients 241 293). The risks of shortterm mortality (odds ratio [OR] 2.77; 95% confidence interval [CI] 2.09, 3.65), long-term mortality (OR 2.03; 95% CI 1.52, 2.71), heart failure (OR 1.96; 95% CI 1.47, 2.62), cardiogenic shock (OR 1.95; 95% CI 1.04, 2.64) and major bleeding (OR 4.28; 95% CI 1.05, 17.14) were increased in patients with anaemia, compared with patients without anaemia. Anaemia was also associated with a higher risk of mortality (adjusted hazard ratio 1.49, 95% CI 1.24, 1.79). CONCLUSIONS: These study findings suggest that anaemia can be used to identify patients with ACS who are at a high risk of death or adverse events, and it may become a promising risk stratification factor in ACS.

Contrast-free MRA at 3.0 T for the detection of intracranial aneurysms.

OBJECTIVE: We prospectively investigated the diagnostic accuracy of contrast-free 3-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) with volume rendering (VR) at 3.0 T to detect intracranial aneurysms in a large cohort of patients. METHODS: We conducted a prospective clinical study including 411 patients with suspected aneurysms and other cerebral vascular diseases who were referred for contrast-free 3D-TOF-MRA at 3.0 T prior to digital subtraction angiography (DSA). 2D-DSA and VR-DSA were regarded as the gold standard. Forty-two patients were excluded. Accuracy, sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) as measures to detect or rule out intracranial aneurysms were determined by patient-, aneurysm-, vessel-, and aneurysm size-based evaluations. RESULTS: In all 369 patients investigated, VR-DSA revealed 307 aneurysms in 246 patients (66.7%) and no aneurysm in 123 patients. The patient-based evaluation by VR 3D-TOF-MRA at 3.0 T yielded an accuracy of 97.6%, a sensitivity of 99.2%, specificity of 94.4%, PPV of 97.2%, and NPV of 98.3% in the detection of intracranial aneurysms. The aneurysm-based evaluation yielded an accuracy of 98.3%, sensitivity of 99.3%, specificity of 96.9%, PPV of 97.8%, and NPV of 99.1%. The vessel-based evaluation yielded accuracy of 98.8%, sensitivity of 99.2%, specificity of 98.5%, PPV of 97.5%, and NPV of 99.6%. The evaluation based on aneurysm sizes yielded similar results. CONCLUSIONS: VR 3D-TOF-MRA at 3.0 T accurately identified the presence of intracranial aneurysms. High PPV and NPV indicated that VR 3D-TOF-MRA at 3.0 T may replace DSA as a contrast-free, noninvasive, and non-radiation-based modality for the diagnosis and screening of intracranial aneurysms.

Successful Transarterial Guglielmi Detachable Coil Embolization of Post-Traumatic Fistula between a Posterior Communicating Artery Aneurysm and the Cavernous Sinus. A Case Report.

SUMMARY: We describe a case of a post-traumatic posterior communicating artery (PCoA) aneurysm-cavernous sinus fistula, which is an extremely rare complication of craniocerebral trauma, successfully treated with endosaccular coil embolization via transarterial route. Endosaccular embolization with Guglielmi detachable coils via transarterial route appears to be a feasible, effective and minimally invasive option for the treatment of post-traumatic fistula between the PCoA aneurysm with a small ostia and the cavernous sinus in the subacute phase.

Endovascular Treatment for Very Small Supraclinoid Aneurysms with Stent-Assisted Coiling. Long-Term Follow-up in Six Cases.

SUMMARY: The endovascular treatment of very small aneurysms (lesions less than 3 mm in maximum diameter) with wide necks remains a challenge for saccular embolization. We retrospectively analyzed our data using Neuroform stent-assisted coiling for very small supraclinoid aneurysms with wide neck to evaluate the feasibility and efficacy of endovascular treatment of these lesions. We conducted a review of our experience and results of endovascular treatments in six patients with seven very small aneurysms. All aneurysms were located at the side wall of the supraclinoid segment of the ICA. They were ruptured in two patients and unruptured in four. The technique of stent-assisted coiling was used in all cases with coiling before stenting and additional coils after deployment of the stent in the same session. All patients were successfully embolized with stent-assisted coiling. The coils were introduced into the lumen for subtotal occlusion in five aneurysms and for partial occlusion in two. During one to two years follow-up angiography, all aneurysms were completely occluded and no recurrence occurred. No complications were observed. Endovascular stent-assisted coil embolization of supraclinoid very small aneurysms with wide necks is effective and feasible. Subtotal aneurysm occlusion might progress to total occlusion.

Establishment of an experimental intracranial internal carotid artery model and the application in covered-stent navigability testing.

BACKGROUND AND PURPOSE: The carotid siphon is a natural barrier to intracranial interventions. Our aim was to make a model of the human intracranial internal carotid artery (ICA) and to test the navigability of covered stents for intracranial applications. MATERIALS AND METHODS: A digital tube was made on the basis of raw MR images of the human ICA. It was transferred into 10 physical models and then coated with silicone by using a 3D rapid prototyping (RP) machine. Ten dogs then underwent surgery. Their common carotid arteries (CCAs) were exposed, cut, and passed through 1 of the tubes. Finally, the vascular models were made by reanastomosis of their CCAs. Eight expended polytetrafluoroethylene (e-PTFE) covered stents (two 3.5 x 16 mm, two 3.5 x 13 mm, two 3.5 x 10 mm, and two 3.5 x 7 mm) were implanted 1 week later. Two dogs remained as controls. The performance of the device was evaluated by angiography and histopathologic examination. RESULTS: Ten animal models were successfully constructed. There was no vascular spasm or thrombosis when assessed by angiography. Destruction of the tunica intima and media was found in the 3.5 x 16 mm stent group. Destruction of the endothelium was found in the 3.5 x 13 mm stent group, and only flattening of the endothelium was found in the 3.5 x 10 mm and 3.5 x 7 mm stent groups. CONCLUSIONS: The experimental model was thought to simulate adequately the geometry of the human ICA and, thus, would be an effective tool for the research and testing of neurovascular devices. The length of the stent is 1 factor influencing the navigability in tortuous vessels.

The feasibility and efficacy of treatment with a Willis covered stent in recurrent intracranial aneurysms after coiling.

BACKGROUND AND PURPOSE: Aneurysm recurrence is an innate problem after coiling, and the recurrence rate is higher in complicated aneurysms. We evaluated the feasibility and efficacy of using the Willis covered stent in treating recurrent aneurysms after coil embolization. MATERIALS AND METHODS: Eight aneurysms in 8 patients treated with detachable coils had confirmed recurrent aneurysms: 3 giant, 1 large, 1 dissecting, and 3 small wide-necked. The recurrent aneurysms involved C3 in 1 patient, C4 in 1, C7 in 5, and V4 in 1. A total of 11 covered stents were implanted into 8 target arteries. Follow-up angiography was performed 1-16 months after the procedure. Clinical follow-up data were collected and retrospectively analyzed, grading as fully recovered, improved, unchanged, or aggravated. RESULTS: Willis covered stent placement succeeded technically in all of the aneurysms. No technique-related adverse event occurred. Total occlusion was achieved immediately in 6 aneurysms, and a small endoleak was observed in 2 aneurysms. No mortality or morbidity occurred during or after the procedures, including during the follow-up period. Follow-up angiograms revealed that all 8 of the recurrent aneurysms were completely isolated, and 8 parent vessels kept patency, except 1 with mild stenosis. Clinical neurologic symptoms fully resolved in 5 patients, improved in 1, and were unchanged in 2 at the end of the follow-up period. CONCLUSIONS: In this small study with a middle-term follow-up, the Willis covered stent was used safely and effectively to occlude recurred aneurysms after coiling. Longer-term follow-up and additional clinical experience are needed to fully determine the safety and efficacy of the device.

Differential expression of insulin-like growth factor-II in specific regions of the late (post day 9.5) murine placenta.

Insulin-like growth factor-II (IGF-II) expression has been implicated as a major determinant of fetal size during murine pregnancy. It remains unclear whether expression in the fetus, the placenta, or both is the overriding factor controlling growth. To gain further understanding of the placental contribution, we mapped IGF-II expression in the fetal vascular and trophoblastic portions of the late murine placenta (day 9.5-18.5). We found that, as in the fetus itself, vasculogenic mesenchyme, in this case derived from the allantois, was the strongest expressor of IGF-II. Trophoblast, on the other hand, while expressing somewhat less IGF-II, showed a dynamic pattern of IGF-II expression, which reflected its continuing differentiation during late pregnancy. Initially (days 9.5 and 12.5), the spongiotrophoblast, which is homologous to the cytotrophoblast columns and shell in early human pregnancy, strongly expressed IGF-II. Later, expression in the spongiotrophoblast was down-regulated as a new population, the so-called glycogen cells, emerged within the spongiotrophoblast (day 12.5-15.5) and went on to invade the mesometrial decidua. Glycogen cells, which are homologous to human intermediate trophoblast, strongly expressed IGF-II. Trophoblast lining the area of maternal-fetal exchange, the labyrinth, on the other hand, maintained a constitutive lower level of IGF-II expression throughout late pregnancy.