Detection of DNA damage in stimulated human lymphocytes after enflurane exposure in vitro.

DNA damage was detected by nucleoid sedimentation in human lymphocytes stimulated with pokeweed mitogen after exposure to enflurane. Enflurane induces DNA damage at an exposure concentration of 0.2 vol%. Higher enflurane concentrations increase the rate of DNA damage. The DNA damage seen after exposure to enflurane concentrations of 0.2 and 3.0% vol is comparable to damage after X-radiation of 0.1 and 0.7 Gy. DNA single-strand breaks can be demonstrated by nucleoid sedimentation and can indicate damage before DNA repair begins. Therefore, detected DNA single-strand breaks may be reversible. However, DNA repair is not always successful and an increased number of DNA single-strand breaks could lead to irreversible DNA damage. The method of nucleoid sedimentation helps to show DNA damage in proliferating cells after exposure to volatile anesthetics or therapeutic gases.     

Thrombophilic conditions in non-cirrhotic portal vein thrombosis.

OBJECTIVE: To study the prevalence of thrombophilic conditions in patients with acute and chronic portal vein thrombosis (PVT) and to compare it with those in patients suffering from deep vein thrombosis (DVT) after lower limb arthroplasty and in healthy subjects. METHODS: Twenty-six patients with spontaneous PVT (20 chronic, 6 acute) with normal liver function and not receiving anticoagulants were evaluated for thrombophilic conditions. Levels of protein C, protein S and antithrombin were compared with those in 50 healthy controls. Factor V gene 'Leiden' mutation (FVL) and high homocysteine levels were looked for in patients with PVT and in 18 patients developing post-arthroplasty lower limb DVT despite anticoagulation. RESULTS: Of 26 patients with PVT, 19 had at least one thrombotic condition (acute PVT 5/6, chronic PVT 14/20) and 12 had more than one such condition; in comparison, of 18 patients with DVT, eight had one thrombophilic condition and one had two such conditions (p=0.03). Patients with PVT had significantly lower levels of protein C, protein S and antithrombin than healthy subjects and those with DVT. Six patients had Factor VIII levels above 150%; four had elevated homocysteine levels and three had detectable anti-cardiolipin antibodies. Three patients with PVT (acute 2, chronic 1) were heterozygous for FVL mutation. CONCLUSIONS: Underlying thrombophilic conditions are common in Indian patients with spontaneous PVT. In many patients, multiple thrombophilic conditions are present and these may play a role in the pathogenesis of PVT.     

Comparison of thrombophilic gene mutations among patients experiencing recurrent miscarriage and deep vein thrombosis

PROBLEM: Inherited thrombophilia has been shown to be a risk factor for cardiovascular disease including deep venous thrombosis as well as reproductive disorders including recurrent pregnancy loss. We have previously reported three out of the 10 thrombophilic mutations studied, plasminogen activator inhibitor-1 (PAI-1) 4G/5G, factor XIII V34L, and homozygous MTHFR C667T, correlated significantly with recurrent pregnancy loss compared with controls. This study was undertaken to compare the frequencies of nine inherited thrombophilias among women with a history of recurrent pregnancy loss with individuals experiencing deep venous thrombosis and fertile controls. METHOD OF STUDY: Six hundred thirty-four participants including 550 women with a history of recurrent pregnancy loss, 43 individuals with deep vein thrombosis and 41 fertile women without a history of recurrent miscarriage. All participants had buccal swabs taken for DNA analyses of nine gene polymorphisms including factor V G1691A, factor V H1299R (R2), factor II Prothrombin G20210A, factor XIII V34L, beta-fibrinogen -455G>A, PAI-1 4G/5G, human platelet antigen 1 a/b (L33P), MTHFR C677T, MTHFR A1298C. Frequencies of thrombophilic gene polymorphisms were compared among the three populations studied. RESULTS: Individuals with a history of DVT had a significantly higher frequency of all of the polymorphisms studied compared with women experiencing a history of recurrent pregnancy loss and the fertile controls. The frequencies of mutations for V34L and PAI-1 4G/5G were significantly increased among women experiencing recurrent pregnancy loss compared with controls. The most prevalent polymorphisms were factor XIII V34L and PAI-1 4G/4G for both individuals with a history of deep vein thrombosis and recurrent pregnancy loss compared with controls. CONCLUSION: Screening for risk factors for inherited thrombophilia with only polymorphisms for factor V von Leiden, factor II prothrombin and MTHFR may be missing the more prevalent identifiers of jeopardy.     

Cadaveric study of anterior and posterior elbow endoscopy portals for endoscopic distal biceps repair: comparative anatomy-at-risk

Purpose

The purpose of this study was to describe neurovascular structures-at-risk during establishment of five portals for access to distal biceps tendon (DBT) in cubital fossa, and to establish relative safety of these portal sites for such access. We hypothesized that all five portals are safe for endoscopic DBT exploration.

Methods

Ten fresh frozen cadaveric elbows were dissected after placement of portals at five potential sites (four anterior, one posterior). Nine neurovascular structures (CV, cephalic vein; LCN, lateral cutaneous nerve; LV, leash of vessels; RN, radial nerve; SRN, superficial radial nerve; PIN, posterior interosseous nerve; RA, radial artery; BA, brachial artery; MN, median nerve) were dissected, and their distances from portal sites were measured. Statistical analysis was performed to determine relative portal safety, and risk of injury to neurovascular structures in relation to each portal was analyzed.

Results

Structures that were significantly “at risk” were RA (p = 0.006), SRN (p = 0.002), and PIN (p = 0.004). RA was significantly “at risk” of injury from portal 4 (p = 0.009). Similarly, SRN was “at risk” from portal 3 (p = 0.036), and the PIN was “at risk” from portal 2 (p = 0.003).

Conclusions

Portal 1 (parabiceps portal) was safe for all neurovascular structures, however, portals 2–4 were significantly closer to neurovascular structures. RA, SRN, and PIN were significantly “at risk” as compared to other structures amongst the portals studied. Portal 5 was relatively safe for SRN and PIN.

Clinical relevance

Portals 1 (parabiceps portal) and 5 (distal posterior) can be safely placed for endoscopic access to the DBT. Portal 4 (open distal anterior) may be used after careful open dissection and under direct vision. Portals 2 and 3 are not recommended for elbow endoscopy.