Structural Basis for Hyperpermeability of Tumor Vessels in Advanced Lung Adenocarcinoma Complicated by Pleural Effusion

BackgroundMalignant pleural effusion (MPE) has a profound impact on quality of life and survival in patients with lung cancer. Identification of the factors within the tumor and its environment that mediate MPE is still lacking.Patients and MethodsIntratumoral microvessel density (MVD), endothelial cell and pericyte (PC) capillary coverage, endothelial cell (EC)-PC relationship, lymphatic endothelium integrity, and the expression of receptor tyrosine kinases were all assessed immunohistochemically in pleural tumor biopsy specimens from 24 patients with lung adenocarcinoma (ADC) with and without pleural disease, with the aim to evaluate the involvement with MPE.ResultsIn the effusion-positive (⁺) specimens, MVD values were found to be significantly higher, and a number of vessels were noted to lack immunoreactivity for ECs (CD31). Likewise, PC α–smooth muscle actin (αSMA) expression was also less extensive in the MPE⁺ cases. The observation of only sporadic staining of PCs can also explain the findings regarding platelet-derived growth factor receptors (PDGFRs), the expression of which, although more prominent in MPE⁺ samples, were almost exclusively detected on tumor stromal cells and not on vascular PCs. Conversely, vascular endothelial growth factor receptors (VEGFRs) appeared on both kinds of cells. With respect to lymphatic vessels, lymphatic intraluminal tumor cells were occasionally found in MPE⁺ specimens.ConclusionOur study suggests that disturbed vessel wall integrity, as well as abnormalities of fluid clearance by the lymphatic system, together with overexpression of growth factors, may take part in the pleural fluid accumulation in lung ADCs. Results of the decreased PC capillary coverage and PDGFR expression in MPE are discussed.     

Magnetic resonance imaging of pelvic entheses—a systematic comparison between short tau inversion recovery (STIR) and T1-weighted,contrast-enhanced,fat-saturated sequences

Objective

To assess the contribution of contrast material in detecting and evaluating enthesitis of pelvic entheses by MRI.

Materials and methods

Sixty-seven hip or pelvic 1.5-T MRIs (30:37 male:female, mean age: 53 years) were retrospectively evaluated for the presence of hamstring and gluteus medius (GM) enthesitis by two readers (a resident and an experienced radiologist). Short tau inversion recovery (STIR) and T1-weighted pre- and post-contrast (T1+Gd) images were evaluated by each reader at two sessions. A consensus reading of two senior radiologists was regarded as the gold standard. Clinical data was retrieved from patients’ referral form and medical files. Cohen’s kappa was used for intra- and inter-observer agreement calculation. Diagnostic properties were calculated against the gold standard reading.

Results

A total of 228 entheses were evaluated. Gold standard analysis diagnosed 83 (36 %) enthesitis lesions. Intra-reader reliability for the experienced reader was significantly (p?=?0.0001) higher in the T1+Gd images compared to the STIR images (hamstring: k?=?0.84/0.45, GM: k?=?0.84/0.47). Sensitivity and specificity increased from 0.74/0.8 to 0.87/0.9 in the STIR images and T1+Gd sequences. Intra-reader reliability for the inexperienced reader was lower (p?>?0.05).

Conclusions

Evidence showing that contrast material improves the reliability, sensitivity, and specificity of detecting enthesitis supports its use in this setting.     

Absorption of protein via the intestinal wall. A quantitative model

Intact, biological active insulin and pancreatic RNase can be absorbed from the intestinal lumen into the blood circulation. The absorption is dependent on the addition of bile acid (sodium cholate) and proteinase inhibitor. The quantitative absorption of insulin and pancreatic RNase has been demonstrated in an in situ model. The amount of insulin absorbed after 30 min from the ileum to the mesenteric vein was 0.025% of the initial amount. Sodium cholate (10 mg/ml) and 3000 KIU/ml aprotinin enhanced this absorption by 30 times. The amount of pancreatic RNase which was absorbed from the ileum to the blood was 0.002% of the initial amount during 30 min. Sodium cholate (10 mg/ml) and 3000 KIU/ml aprotinin increased the absorption by a factor of 200. No damage occurred to the intestine during the experimental procedures. The sieving characteristics of the intestinal wall were not altered by the presence of sodium cholate and proteinase inhibitor in the intestinal lumen. These results suggest that sodium cholate and proteinase inhibitors can facilitate the absorption of intact, biologically active proteins across the intestinal wall.     

Sensory peripheral neuropathy of vitamin B12 deficiency: A primary demyelinating disease?

Summary In five patients with peripheral neuropathy due to vitamin B₁₂ deficiency, electrodiagnostic studies demonstrated severe reduction in sensory nerve conduction velocities compatible with a demyelinating disorder affecting sensory nerve fibres. It is suggested that in some patients lack of vitamin B₁₂ may cause primary sensory demyelinating neuropathy.     

A common mutation A1298C in human methylenetetrahydrofolate reductase gene: association with plasma total homocysteine and folate concentrations.

Methylenetetrahydrofolate reductase (MTHFR) is one of the main regulatory enzymes of homocysteine metabolism. Previous studies revealed that a common mutation in MTHFR gene C677T is related to hyperhomocysteinemia and occlusive vascular pathology. In the current study, we determined the prevalence of a newly described mutation in the human MTHFR gene A1298C, and the already known C677T mutation, and related them to plasma total homocysteine and folate concentrations. We studied 377 Jewish subjects, including 190 men and 186 women aged 56.8 +/- 13 y (range 32-95 y). The frequency of the homozygotes for the A1298C and the C677T MTHFR mutations was common in the Jewish Israeli population (0.34 and 0.37, respectively). Subjects homozygous (TT) for the C677T mutation had significantly greater plasma total homocysteine concentrations (P < 0.01) than subjects without the mutation (CC). Homozygotes (CC) for the A1298C mutation did not have elevated plasma total homocysteine concentrations. Our study indicated that subjects with the 677CC/1298CC genotype had significantly lower concentrations (P < 0. 05) than those with a 677CC/1298AA genotype. Neither mutation (the A1298C and the C677T) was associated with established cardiovascular risk factors such as hypertension, elevated total cholesterol or body mass index.     

Familial perinatal hemochromatosis: a disease that causes recurrent non-immune hydrops.

Perinatal hemochromatosis is a rare disorder with an enormous iron overload in the parenchymal organs, especially the liver, pancreas, heart and endocrine glands. Elements of the reticuloendothelial system are relatively spared. The clinical course is rapidly progressive and the disease is invariably fatal. Several siblings are described in the literature. Herein, we describe one pair of full siblings affected by the disease, wherein the clinical presentation was hydrops. We suggest that hemochromatosis should be considered in the differential diagnosis of hydrops fetalis.