Ultrasound Characteristics of Calf Deep Vein Thrombosis and Residual Vein Obstruction After Low Molecular Weight Heparin Treatment.

OBJECTIVE/BACKGROUND: Calf deep vein thrombosis (CDVT) is frequently found in symptomatic outpatients, but CDVT ultrasound diagnostic criteria are still debated. It has been proposed that only clots with ≥5 mm maximum diameter can be considered as CDVT. AIMS: To assess clot diameters and characteristics of CDVT, and to assess the recanalization rate of CDVT after anticoagulant treatment. METHODS: In a prospective, multicenter cohort study symptomatic outpatients in whom CDVT was diagnosed by ultrasound were enrolled. Posterior tibial, fibular, medial and lateral gastrocnemius, and soleal veins were compressed transversally over their entire length. Clot diameter was measured during maximum compression and ultrasound was repeated after 6 weeks of low molecular weight heparin treatment. RESULTS: In 172 patients (age 70 ± 1 y, male 32%) CDVT was detected in 132 (76.7%) muscle veins only, and in 24 (14%) axial veins only, while 16 (9.3%) patients had both muscular and axial CDVT. A total of 212 clots were found with a diameter of 5.8 ± 1.8 mm (IQR 4.5-6.8 mm) with the 10th percentile being ≥3.5 mm. A cut off value of ≥5 mm had a sensitivity of 0.76 (95% CI 0.69-0.82), whereas a value of ≥3.5 mm had a sensitivity of 0.94 (95% CI 0.89-0.97). Recanalization (i.e. residual vein obstruction ≤2 mm) was found in 51% of patients and the recanalization rate was not correlated with clot diameter at enrolment (rho -0.128 p = 0.93) or with type of CDVT (axial vs. muscular thrombosis). Patients with significantly reduced mobility had lower probability of CDVT recanalization. CONCLUSION: A clot diameter ≥5 mm is found in only 76% of CDVT patients and a clot diameter ≥3.5 mm may be more appropriate as a threshold for CDVT. After 6 weeks of anticoagulant treatment, half of CDVT patients had recanalization and recanalization was not correlated with clot characteristics at enrolment, but with mobility of the patients.

Flow-mediated dilation, carotid wall thickness and HDL function in subjects with hyperalphalipoproteinemia.

BACKGROUND AND AIMS: The relationships between very high plasma HDLc and subclinical atherosclerosis are still a matter of debate. METHODS AND RESULTS: Twenty subjects with primary hyperalphalipoproteinemia (HAL, with HDLc in the highest 10th percentile and absence of overt secondary causes of this condition), aged 30-65 years, were compared with 20 age and sex-matched controls. Lipid determination, lipoprotein particle distribution (Lipoprint(®)), Cholesterol Efflux Capacity (CEC), plasma adhesion molecule, analyses of CETP, SRB1 and LIPG genes and of different markers of subclinical vascular disease (ankle-brachial index, ABI; carotid intima-media thickness, cIMT; brachial-artery flow mediated dilation, FMD) were performed. Fasting HDLc levels were 40 mg/dl higher in HAL subjects while LDLc concentration was comparable to control group. CETP gene analysis in HAL subjects identified one novel rare Single Nucleotide Polymorphism (SNP, Asp131Asn), possibly damaging, while the common SNP p.Val422Ile was highly prevalent (50% vs. 27.4% in a control population). No rare mutations associated with HAL were found in SR-B1 and LIPG genes. Polyacrylamide gel electrophoresis in HAL subjects disclosed larger and more buoyant HDL particles than in controls, while LDL profile was much more similar. ABI, cIMT and arterial plaques did not differ in cases and controls and the two groups showed comparable FMD at brachial artery examination. Similarly, ABCA1 and ABCG1 HDL-mediated CEC, the most relevant for atheroprotection, did not discriminate between the groups and only ABCG1 pathway seemed somewhat related to arterial reactivity. CONCLUSIONS: HDL dimension, function and genetics seem scarcely related to subclinical atherosclerosis and vascular reactivity in middle-aged HAL subjects.

Immunosuppressive activity of a purified spleen extract (lymphocytic chalone?) is not due to polyamines spermine and spermidine.

Spermine, spermidine and a purified spleen extract (PSE) have been compared in vivo in these three tests: hemolytic plaque forming capacity in sensitized mice, delayed hypersensitivity reaction and 3H-thymidine incorporation into various tissue cells. The results obtained demonstrated that the immunosuppressive activity of PSE cannot be attributed to those polyamines. Ion exchange analysis of PSE before and after acid hydrolysis confirmed the absence of free and/or bound polyamines in the studied extract.

Purification of immunosuppressive factors extracted from bovine spleen (lymphoid chalone).

A low molecular weight immunosuppressive factor FA which is able to reduce the blastic transformation capacity of lymphoid cells from treated mice has been characterized. It was prepared from a bovine spleen acetone powder and found to be associated partly with high molecular weight carriers in the form of an active complex characterized previously as part of a 'lymphoid chalone' fraction. FA may be obtained by selective ultrafiltration of F followed by P-2 Biogel chromatography of the ultrafiltrate. Thymidine, deoxyinosine and deoxycytidine have been identified as the major constituents of FA by mass spectrometry, ultraviolet absorption data and thin layer chromatography. However, none of these nucleotides has the biological activity of FA.