Paradoxical preexcitation during cryoablation of a concealed parahisian accessory pathway

A 16‐year‐old male presented with an orthodromic atrioventricular reentrant tachycardia over a concealed parahisian accessory pathway (AP). Cryoablation of the AP resulted in transient manifestation of a fully preexcited sinus rhythm of parahisian AP morphology. Potential causes for the paradoxical preexcitation include inadvertent atrioventricular nodal block, sourse‐sink mismatch, as well as the activation of a dormant AP capable of anterograde conduction.     

In vivo Heparan Sulfate Treatment Alters the Immune Response of Normal and LLC-Bearing Mice

Despite the large amount of research dedicated to the understanding and treatment of tumor growth, the majority of cancers continue to lack effective therapeutic options. As in the case of most solid tumors, growth requires evasion of the host immune system. Our previous work using the Lewis Lung Carcinoma (LLC) model of tumor bearing (TB)-mice has shown several tumor-induced immune suppressing effects to be present. These effects include a decreased T-cell proliferative response to Con A and altered cytokine secretion patterns that favor neither a Th1 nor a Th2 response. To address these immune alterations, immune modulating approaches have been a central area of study. Of the many potential immune modulating compounds, we believe promising therapeutic potential lies in the heparin family. Heparan sulfate (HS), in particular, has been shown to increase T-cell proliferative response in non TB-mouse splenocytes as well as promotion of a beneficial Th1 response. In this paper, we studied the potential of HS to decrease tumor burden via in vivo treatment of TB-mice. Results showed both normal and TB-mice splenocytes had a dose response change in proliferation as a result of HS treatment. Furthermore, splenocytes from HS treated TB-mice showed a potentially beneficial decrease in basal level proliferation. On gross examination, HS treatment produced a decrease in tumor surface necrosis with a visible (2 ± 1.8%) surface necrotic area in treated mice as opposed to a (43 ± 16%) surface necrotic area in untreated mice. HS treatment decreased TB-mice splenomegaly when comparing mice spleen weights in treated (0.3 ± 0.05 g) vs. untreated (0.14 ± 0.02 g) groups. These results show a potential role of HS as an immune modulating agent with antitumor properties.     

Intra-articular pressure profile of the knee joint in a spectrum of inflammatory arthropathies

OBJECTIVES—The intra-articular pressure (IAP) rises significantly after isometric quadriceps contraction in patients with rheumatoid synovitis, a process that may temporarily impede synovial blood flow and cause oxidative injury. In acute traumatic knee effusions (ATE) pressure rises are trivial. This study compared the IAP profiles of patients with ATE with three different populations—an acute synovitis on the background of a chronic inflammatory arthropathy, a chronic low grade inflammatory arthropathy, and an acute intermittent inflammatory arthropathy. The study objective was to discover if the pressure profiles observed in these groups reflect an influence of the inflammatory process or time or both.
METHODS—Thirty three patients were studied. These were divided into four subgroups; group 1: five acute traumatic knee effusions (ATE); group 2: acute effusions on the background of a chronic inflammatory arthropathy: seven rheumatoid arthritis (RA), five psoriatic arthritis (PsA); group 3: seven osteoarthritis (OA) and group 4: acute effusions on the background of an intermittent inflammatory arthropathy: seven pyrophosphate arthropathy (PA), one amyloid (AA), one Behcet's (B). IAP was measured (mm Hg) at rest and during isometric quadriceps contraction using the hand held portable 295-1 intra-compartmental pressure monitor system (Stryker UK). The volume of synovial fluid aspirated was recorded.
RESULTS—Expressed as medians (interquartile range). Resting IAP was; ATE 6 (2-12), RA 8 (5-47), PsA 18 (11-31), OA 17 (7-21), PA 25 (9-29), AA 14, and B 12. IAP increased in all subjects during isometric contraction; ATE 9 (7-16), RA 56 (33-150), PsA 52 (43-85), OA 56 (20-116), PA 53 (41-65), AA 47, B 57 and the IAP rise was significant (p<0.05) in all except the ATE group (p>0.05). The volume of synovial fluid aspirated in groups 2, 3, and 4 correlated significantly with the magnitude of the IAP change (r = 0.45, p < 0.05).
CONCLUSION—The IAP rise during isometric quadriceps contraction is a feature of all patients with an inflammatory based effusion irrespective of the duration of the effusion. This is not the case in patients with an ATE. In inflammatory synovitis the rise in intra-articular pressure with isometric quadriceps contraction relates to effusion volume. It is concluded that the inflammatory process prevents reflex muscle inhibition, a locally protective mechanism that minimises the potential for intermittent ischaemia/oxidative injury.