Role of saphenous vein wall in the pathogenesis of primary varicose veins

UNLABELLED: Varicose veins may be due to weakness of the vein wall as a result of structural problems. There are conflicting findings in the literature about these problems especially concerning collagen, elastin and smooth muscle cells content. The aim of this study was to look at the structural abnormalities of varicose veins (with and without valvular incompetence).

MATERIALS AND METHODS: We studied 70 specimens of long saphenous veins from 35 patients (24 with varicose and 11 with normal veins). Two specimens were taken from each vein approximately 3-4 cm from the saphenofemoral junction. Vein specimens were processed for histological and electron microscopic studies. Both qualitative and quantitative analyses were performed to assess the degree of wall changes. Using the image analyzer, contents of collagen, elastin and smooth muscle cells, in addition to intimal and medial thickness, were measured.

RESULTS: Light microscopy revealed significant increase in intimal and medial thickness and collagen content of media and significant decrease in elastin content in varicose veins compared with normal veins. There was no statistical significant difference between varicose veins with and without saphenofemoral valve incompetence. Electron microscopy showed marked degenerative changes in intima and media of varicose veins.

CONCLUSION: The findings in our study supported the theory of primary weakness of the vein wall as a cause of varicosity. This weakness is due to intimal changes, disturbance in the connective tissue components and smooth muscle cells.

The pathogenesis of venous thromboembolism in cancer: emerging links with tumour biology.

Venous thromboembolism (VTE) is a frequent complication in individuals with cancer and is considered to be a cause of substantial mortality. Epidemiological studies identify malignancy as an independent VTE risk factor and show that cancer patients are at increased risk of both initial and recurrent VTE events. The risk due to cancer is compounded by the effects of chemotherapy and other treatments. The pathogenesis of cancer-associated VTE is complex involving multiple interactions between tumours and various components of haemostasis. The development of a systemic hypercoagulable state is considered a key pathogenetic feature and is attributed to tumour expression of tissue factor and other procoagulants, activation of vascular cells by tumour-derived cytokines and adhesive interactions between tumour cells and host cells. An increasing body of evidence indicates that the activation of haemostasis in malignant disease contributes to tumour growth and progression by stimulation of intracellular signalling pathways. The interaction of tissue factor, thrombin and other coagulation factors with protease activated receptor (PAR) proteins expressed by tumour cells and host vascular cells leads to the induction of genes related to the processes of angiogenesis, cell survival and cell adhesion and migration.

The alternative sigma factor sigma B of Staphylococcus aureus modulates virulence in experimental central venous catheter-related infections.

The impact of the alternative sigma factor sigma B (SigB) on pathogenesis of Staphylococcus aureus is not conclusively clarified. In this study, a central venous catheter (CVC) related model of multiorgan infection was used to investigate the role of SigB for the pathogenesis of S. aureus infections and biofilm formation in vivo. Analysis of two SigB-positive wild-type strains and their isogenic mutants revealed uniformly that the wild-type was significantly more virulent than the SigB-deficient mutant. The observed difference in virulence was apparently not linked to the capability of the strains to form biofilms in vivo since wild-type and mutant strains were able to produce biofilm layers inside of the catheter. The data strongly indicate that the alternative sigma factor SigB plays a role in CVC-associated infections caused by S. aureus.

Vitamin D deficiency and insufficiency in pregnant women: a longitudinal study.

Maternal vitamin D insufficiency is associated with childhood rickets and longer-term problems including schizophrenia and type 1 diabetes. Whilst maternal vitamin D insufficiency is common in mothers with highly pigmented skin, little is known about vitamin D status of Caucasian pregnant women. The aim was to investigate vitamin D status in healthy Caucasian pregnant women and a group of age-matched non-pregnant controls living at 54–55°N. In a longitudinal study, plasma 25-hydroxyvitamin D (25(OH)D) was assessed in ninety-nine pregnant women at 12, 20 and 35 weeks of gestation, and in thirty-eight non-pregnant women sampled concurrently. Plasma 25(OH)D concentrations were lower in pregnant women compared to non-pregnant women (P < 0·0001). Of the pregnant women, 35, 44 and 16 % were classified as vitamin D deficient (25(OH)D < 25 nmol/l), and 96, 96 and 75 % were classified as vitamin D insufficient (25(OH)D < 50 nmol/l) at 12, 20 and 35 weeks gestation, respectively. Vitamin D status was higher in pregnant women who reported taking multivitamin supplements at 12 (P < 0·0001), 20 (P = 0·001) and 35 (P = 0·001) weeks gestation than in non-supplement users. Vitamin D insufficiency is evident in pregnant women living at 54–55°N. Women reporting use of vitamin D-containing supplements had higher vitamin D status, however, vitamin D insufficiency was still evident even in the face of supplement use. Given the potential consequences of hypovitaminosis D on health outcomes, vitamin D supplementation, perhaps at higher doses than currently available, is needed to improve maternal vitamin D nutriture.

Concomitant and antecedent deep venous thrombosis and cancer survival in male US veterans

Survival is reportedly worse in patients with cancer concurrently diagnosed with deep venous thrombosis. However, information on specific malignancies is limited. From a cohort study of male US veterans we identified incident cancer cases (n aEuroS== aEuroS412 008) and compared survival patterns among those with versus without a history of deep venous thrombosis. Using Cox proportional hazard models, we estimated hazard ratios (HRs) and 95%% confidence intervals as measures of the relative risk of dying. Individuals with (versus without) a concomitant deep venous thrombosis and cancer diagnosis had a higher risk of dying (HR aEuroS== aEuroS1.38; 1.28--1.49). The most prominent excess mortality (HR aEuroS== aEuroS1.29--2.55) was observed among patients diagnosed with deep venous thrombosis at the time of diagnosis of lung, gastric, prostate, bladder, or kidney cancer. Increased risk of dying was also found among cancer patients diagnosed with deep venous thrombosis 1 year (HR aEuroS== aEuroS1.14; 1.07--1.22), 1--5 years (HR aEuroS== aEuroS1.14; 1.10--1.19), and > 5 years (HR aEuroS== aEuroS1.27; 1.23--1.31) before cancer; this was true for most cancer sites (HR aEuroS== aEuroS1.17--1.64). In summary, antecedent deep venous thrombosis confers a worse prognosis upon cancer patients. Advanced stage at diagnosis, treatment effects, lifestyle factors, and comorbidity could explain differences by cancer site and time frame between a prior deep venous thrombosis diagnosis and cancer outcome.

Diabetic retinopathy: quantitative variation in capillary basement membrane thickening in arterial or venous environments

Diabetes mellitus was induced in male beagles by a single injection of an alloxan and streptozotocin cocktail and fasting blood sugar levels maintained between 15 and 20 mmol/l. Five years after induction of diabetes, three diabetic animals were sacrificed, together with sex and age-matched controls, and the retinas fixed for either transmission electron microscopy (TEM) or trypsin digestion. In TEM specimens, capillaries in close proximity to the major vessels were designated as either AE (arterial environment) or VE (venous environment) and the thickness of their basement membranes (BMs) measured using an image analyser based two dimensional morphometric analysis system. Results show that the BMs of retinal capillaries from the diabetic dogs were significantly thicker than those from control dogs. Furthermore, within the diabetic group the AE capillaries had thicker BMs than VE capillaries (p less than or equal to 0.05). The controls, however, showed no significant difference in BM thickness between AE and VE capillaries. Although many of the capillaries designated as AE or VE would actually have been derived from the opposite side of the circulation, with respect to BM thickness, they conformed to values of their specific group. The conclusion is that diabetic capillaries are more vulnerable to BM thickening in an arterial environment than in a venous environment.

Pinch grafting for chronic venous leg ulcers in general practice

Twenty-five patients with chronic venous leg ulcers were treated in general practice by pinch grafting. Fifteen of the ulcers (60%) were completely healed one year after grafting. Prior to grafting 19 patients (76%) complained of daily pain in the ulcer. These patients experienced complete relief from pain after grafting. Pinch grafting is a simple, safe and effective therapy when applied in a domiciliary environment.