Smad2-dependent glycosaminoglycan elongation in aortic valve interstitial cells enhances binding of LDL to proteoglycans

ObjectiveCalcific aortic valve disease is a progressive condition that shares some common pathogenic features with atherosclerosis. Transforming growth factor-β1 is a recognized mediator of atherosclerosis and is expressed in aortic valve lesions. Transforming growth factorβ1 stimulates glycosaminoglycan elongation of proteoglycans that is associated with increased lipid binding. We investigated the presence of transforming growth factor-β1 and downstream signaling intermediates in diseased human aortic valves and the effects of activated transforming growth factor-β1 receptor signaling on aortic valve interstitial cell proteoglycan synthesis and lipid binding as a possible mechanism for the initiation of the early lesion of calcific aortic valve disease.Methods and resultsDiseased human aortic valve leaflets demonstrated strong immunohistochemical staining for transforming growth factor-β1 and phosphorylated Smad2/3. In primary porcine aortic valve interstitial cells, Western blots showed that transforming growth factor-β1 stimulated phosphorylation in both the carboxy and linker regions of Smad2/3, which was inhibited by the transforming growth factor-β1 receptor inhibitor SB431542. Gel electrophoresis and size exclusion chromatography demonstrated that SB431542 decreased transforming growth factor-β1-mediated [³⁵S]-sulfate incorporation into proteoglycans in a dose-dependent manner. Further, in proteoglycans derived from transforming growth factor-β1-treated valve interstitial cells, gel mobility shift assays demonstrated that inhibition of transforming growth factor-β1 receptor signaling resulted in decreased lipid binding.ConclusionsClassic transforming growth factor-β1 signaling is present in human aortic valves in vivo and contributes to the modification of proteoglycans expressed by valve interstitial cells in vitro. These findings suggest that transforming growth factor-β1 may promote increased low-density lipoprotein binding in the early phases of calcific aortic valve disease.     

Unraveling Tumor Grading and Genomic Landscape in Lung Neuroendocrine Tumors

Currently, grading in lung neuroendocrine tumors (NETs) is inherently defined by the histological classification based on cell features, mitosis count, and necrosis, for which typical carcinoids (TC) are low-grade malignant tumors with long life expectation, atypical carcinoids (AC) intermediate-grade malignant tumors with more aggressive clinical behavior, and large cell NE carcinomas (LCNEC) and small cell lung carcinomas (SCLC) high-grade malignant tumors with dismal prognosis. While Ki-67 antigen labeling index, highlighting the proportion of proliferating tumor cells, has largely been used in digestive NETs for assessing prognosis and assisting therapy decisions, the same marker does not play an established role in the diagnosis, grading, and prognosis of lung NETs. Next generation sequencing techniques (NGS), thanks to their astonishing ability to process in a shorter timeframe up to billions of DNA strands, are radically revolutionizing our approach to diagnosis and therapy of tumors, including lung cancer. When applied to single genes, panels of genes, exome, or the whole genome by using either frozen or paraffin tissues, NGS techniques increase our understanding of cancer, thus realizing the bases of precision medicine. Data are emerging that TC and AC are mainly altered in chromatin remodeling genes, whereas LCNEC and SCLC are also mutated in cell cycle checkpoint and cell differentiation regulators. A common denominator to all lung NETs is a deregulation of cell proliferation, which represents a biological rationale for morphologic (mitoses and necrosis) and molecular (Ki-67 antigen) parameters to successfully serve as predictors of tumor behavior (i.e., identification of pathological entities with clinical correlation). It is envisaged that a novel grading system in lung NETs based on the combined assessment of mitoses, necrosis, and Ki-67 LI may offer a better stratification of prognostic classes, realizing a bridge between molecular alterations, morphological features, and clinical behavior.     

Large cell carcinoma of the lung: clinically oriented classification integrating immunohistochemistry and molecular biology

This study aimed at challenging pulmonary large cell carcinoma (LLC) as tumor entity and defining different subgroups according to immunohistochemical and molecular features. Expression of markers specific for glandular (TTF-1, napsin A, cytokeratin 7), squamous cell (p40, p63, cytokeratins 5/6, desmocollin-3), and neuroendocrine (chromogranin, synaptophysin, CD56) differentiation was studied in 121 LCC across their entire histological spectrum also using direct sequencing for epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations and FISH analysis for ALK gene translocation. Survival was not investigated. All 47 large cell neuroendocrine carcinomas demonstrated a true neuroendocrine cell lineage, whereas all 24 basaloid and both 2 lymphoepithelioma-like carcinomas showed squamous cell markers. Eighteen out of 22 clear cell carcinomas had glandular differentiation, with KRAS mutations being present in 39 % of cases, whereas squamous cell differentiation was present in four cases. Eighteen out of 20 large cell carcinomas, not otherwise specified, had glandular differentiation upon immunohistochemistry, with an exon 21 L858R EGFR mutation in one (5 %) tumor, an exon 2 KRAS mutation in eight (40 %) tumors, and an ALK translocation in one (5 %) tumor, whereas two tumors positive for CK7 and CK5/6 and negative for all other markers were considered adenocarcinoma. All six LCC of rhabdoid type expressed TTF-1 and/or CK7, three of which also harbored KRAS mutations. When positive and negative immunohistochemical staining for these markers was combined, three subsets of LCC emerged exhibiting glandular, squamous, and neuroendocrine differentiation. Molecular alterations were restricted to tumors classified as adenocarcinoma. Stratifying LCC into specific categories using immunohistochemistry and molecular analysis may significantly impact on the choice of therapy.     

Doppler sonographic examinations of uteroplacental, fetoplacental, and fetal hemodynamics and their prognostic value in preterm labor.

Doppler examinations of different uteroplacental vessels (uterine arteries, arcuate arteries), umbilical artery, fetal thoracic aorta, and median cerebral artery were performed on 55 patients with idiopathic preterm labor (24.5 to 32.5 weeks). Thirty normal pregnancies of corresponding gestational age served as a control group. Significant differences of median values between the preterm labor and control group were found only for the resistance index (RI) in the central arcuate artery and for the pulsatility index (PI) in the fetal thoracic aorta. In about twenty percent of pregnancies in preterm labor, pathological values of RI and PI in uteroplacental and fetal vessels account for the presence of an impaired perfusion. Elevated PI in the uterine artery placental site and normal RI in the fetal thoracic aorta, correlate significantly to a shorter prolongation of pregnancy, lower gestational age on birth, and lower birth weight. The combination of these two blood flow indices (maternal PI greater than 0.90 and fetal RI less than 0.90) allow us to predict a preterm birth in a high percentage of cases (sensitivity 87.5%, specificity 100%, positive predictive value 100%, negative predictive value 93%).     

Ectopic endocrine pancreatic tumour simulating splenic angiosarcoma

A case of ectopic endocrine pancreatic tumour that had developed within the spleen of a 46-year-old man is reported. The tumour was highly vascularized through the splenic artery, angiographically simulating an angiosarcoma. The histological pattern was typical of an endocrine tumour, and its nature was confirmed by a positivity for keratin, chromogranin A and somatostatin. Foci of atrophic pancreatic tissue were detected in the tumour capsule.     

Neurosteroids: Expression of Functional 3β-Hydroxysteroid Dehydrogenase by Rat Sensory Neurons and Schwann Cells

Steroids which are synthesized within the nervous system, such as progesterone, have been termed 'neurosteroids'. Levels of progesterone are much larger in peripheral nerves of rats and mice than in plasma, and persist after removal of the steroidogenic endocrine glands. Schwann cells are a source of progesterone: when isolated from embryonic dorsal root ganglia, they can synthesize progesterone from pregnenolone, the obligate precursor of all steroids. Locally produced progesterone has been shown to play an important role in myelination of peripheral nerve. We show here that sensory neurons from embryonic dorsal root ganglia also express 3β-hydroxysteroid dehydrogenase and can convert [³H]pregnenolone to [³H]progesterone. Moreover, when cultured under different conditions and incubated for 24 h in the presence of 100 nM [³H]pregnenolone, they produce 5–10 times more [³H]progesterone than Schwann cells. The conversion of pregnenolone to progesterone by neurons is further increased by a diffusible factor produced by Schwann cells. Sensory neurons can also metabolize progesterone to 5α-dihydroprogesterone, but unlike Schwann cells, they do not produce 3α,5α-tetrahydroprogesterone, a potent positive allosteric modulator of γ-aminobutyric acid type A receptors. We also show that cells isolated from the adult nervous system still have the capacity to convert [³H]pregnenolone to progesterone and its 5α-reduced metabolites: neurons and Schwann cells purified from dorsal root ganglia of 6 week old male rats show a similar pattern of pregnenolone metabolism to cells isolated from 18 day old embryos. These findings further support the important role of progesterone in the development and regeneration of the peripheral nervous system.     

Rapidly growing yolk sac tumor of the ovary in a lactating patient

A case of yolk sac tumor of the ovary exceptional for its size and rapid development is here presented and discussed. The patient was feeding her baby delivered only two months earlier. Hormonal influences of pregnancy and lactation might have played an important role in the progression of this neoplasm.     

Heller's extramucosal cardiomyotomy under endoscopic control. The long-term results

Twenty-five patients underwent Heller cardiomyotomy with Nissen fundoplication, made through an abdominal incision under endoscopic control. Long term results were evaluated according to clinical, radiological, manometric and 24-hour esophageal pH-metric studies. Clinical results were excellent in 44% of the patients, good in 40%, fair in 4% and bad in 12%. The four unsatisfactory results are due to recurrence of dysphagia in one case and to appearance of GER in the others. Postoperative X-ray controls and manometric tests showed a significative decrease in the esophageal diameter, in resting and post swallowing LES and esophageal body pressure. The 24-hour pH test showed an abnormal percentage of time with pH less than 4 in two patients, and a direct connection with clinical and endoscopic results. Endoscopic control of myotomy allows us to define precisely the extension of the functional stenosis and to eliminate completely the dysphagia. In the postoperative evaluation the 24-hour pH monitoring allows an early identification of GER, and the prevention of possible complications even in the absence of any clinical sign.