Thoracic aortic dissection (TAD) is an aortic disease associated with dysregulated extracellular matrix composition and de-differentiation of vascular smooth muscle cells (SMCs). Growth Differentiation Factor 11 (GDF11) is a member of transforming growth factor β (TGF-β) superfamily associated with cardiovascular diseases. The present study attempted to investigate the expression of GDF11 in TAD and its effects on aortic SMC phenotype transition. GDF11 level was found lower in the ascending thoracic aortas of TAD patients than healthy aortas. The mouse model of TAD was established by β-aminopropionitrile monofumarate (BAPN) combined with angiotensin II (Ang II). The expression of GDF11 was also decreased in thoracic aortic tissues accompanied with increased inflammation, arteriectasis and elastin degradation in TAD mice. Administration of GDF11 mitigated these aortic lesions and improved the survival rate of mice. Exogenous GDF11 and adeno-associated virus type 2 (AAV-2)-mediated GDF11 overexpression increased the expression of contractile proteins including ACTA2, SM22α and myosin heavy chain 11 (MYH11) and decreased synthetic markers including osteopontin and fibronectin 1 (FN1), indicating that GDF11 might inhibit SMC phenotype transition and maintain its contractile state. Moreover, GDF11 inhibited the production of matrix metalloproteinase (MMP)-2, 3, 9 in aortic SMCs. The canonical TGF-β (Smad2/3) signalling was enhanced by GDF11, while its inhibition suppressed the inhibitory effects of GDF11 on SMC de-differentiation and MMP production in vitro. Therefore, we demonstrate that GDF11 may contribute to TAD alleviation via inhibiting inflammation and MMP activity, and promoting the transition of aortic SMCs towards a contractile phenotype, which provides a therapeutic target for TAD.

A novel porcine pathogen tentatively named P1, which was obtained from the sera of the pigs exhibiting clinical signs of postweaning multisystemic wasting syndrome (PMWS) experimentally caused the classical clinic signs and pathologic lesions of the disease in pigs by direct in vivo injection with P1 DNA plasmids. Twenty colostrum-fed (CF) pigs that were free of PCV2 and P1 at 1 month of age were randomly designated equally to two groups. Group 1 pigs were each injected with 400 µg of the cloned P1 plasmid DNA into the superficial inguinal lymph nodes and Group 2 were injected with same amount of the empty pSK vector DNA and served as controls. Viremias were positively detected in 8 of 10 P1 infected pigs from 14-21 days post-inoculation (dpi). The 8 infected animals showed pallor of skin and diarrhea. Gross lesions in the pigs euthanized on 35 dpi were similarly characterized by encephalemia, haemorrhage of the bladder mucosa, haemorrhage of the superficial inguinal lymph nodes, lung atrophy and haemorrhage. Histopathological lesions were arteriectasis and telangiectasia of the cavitas subarachnoidealis, interstitial pneumonia, mild atrophy of the cardiac muscle cells, histiocytic hyperplasia of the follicles in the tonsils, and haemorrhage of the inguinal lymph nodes. P1 DNA and antigens were confirmed by PCR and immunohistochemistry in the tissues and organs of the infected pigs, including the pancreas, bladders, testicles/ovaries, brains, lungs and liver. There were no obvious clinical signs and pathological lesions in the control pigs. This study demonstrated that P1 infection is one of the important pathologic agents on pig farms.

Aneurysmal disease is uncommon in children, and its presence often leads to suspicion of genetic disorders (Loeys-Dietz syndrome, Marfan syndrome, Ehlers-Danlos syndrome, tuberous sclerosis), trauma, and infection. We describe the case of a newborn boy with generalized left lower limb hypoplasia associated with diffuse areas of arteriectasis combined with areas of stenosis and fusiform aneurysms of the iliac, femoral, and popliteal arteries. No additional vascular territories were affected. The patient was asymptomatic, and no therapeutic intervention has been considered. Numerous complementary imaging and laboratory examinations failed to establish a definitive diagnosis. This collection of findings has not been previously reported.

In 1942, Leriche described the first "dolichomégaartères" (or "arteriomegaly" according to the definition subsequently proposed by Anglo-Saxon researchers). We detected 199 cases of arteriomegaly (16.29% of cases examined) during a review of 1,221 translumbar arteriographies of the lower limbs performed from 1980 to 1985 in the vascular radiology department of our hospital. The percentage of associated aneurysms was 33.16%. The possible dysplastic pathogenesis of the affection and the differential diagnosis with atherosclerosis and other vascular affections found in connective tissue diseases is noted. Histopathology showed dystrophic lesions of the media and especially of the elastic fibers as well as occasional associated venous lesions and a familial basis. The peripheral symptomatology was acute, pseudoembolic and severe as revealed by ischemia and cyanosis. There was no collateral circulation. Medical treatment consisted especially in anti-coagulant and hypervolemic hemorrheologic therapy during ischemia. Ultrasonography enabled us to monitor the regular, systematic course of arteriomegaly, to make the diagnosis initially, to measure the exact size of the arteries, to observe the morphology of the wall and, moreover, to determine the presence or not of megaveins capable of reinforcing the dysplastic genesis of arteriomegaly.

Intracranial diffuse arteriectasis may be located to the carotid and vertebral arteries and their branches separately or concomitantly and associated with saccular aneurysms and generalized arteriectasis. The principle clinical aspects of intracranial arteriectasis are cranial nerve palsies, particularly of the cerebellopontine region in association or not with cerebellar disorders and transient or permanent motor deficiencies. Arterial hypertension exists in a high proportion of cases. The some times complex clinical picture may be due to pressure of nervous structures by the ectatic vessels, ischemia or hemorrhagy. Mostly affected are men over 50 years of age although arteriectasis has been observed in younger patients including children and infants. The disease can be suspected clinically but is generally diagnosed after neuroradiological studies, mostly angiography and/or computerized tomography. Initially arteriectasis was supposed to be the result of arteriosclerosis but histopathology has shown that it may be independent of arteriosclerosis and appears to be the result of a congenital abnormality in the elastic component of the vessel wall. On the basis of our six observations and those already published it becomes apparent that diffuse intracranial arteriectasis represents a specific disease.