Ischaemia-induced changes in canine cardiac sarcoplasmic reticulum

Effects of myocardial ischaemia on sarcoplasmic reticulum (SR) of dog hearts were investigated. Regional ischaemia was produced by occlusion of the left circumflex artery, and a microsomal fraction enriched in vesicles of SR was isolated from subendocardium (Endo) and subepicardium (Epi) of control and ischaemic areas of the heart. No significant changes occurred in ischaemic Epi. A loss of in vitro activities (ie calcium transport and ATPase) was found for SR from ischaemic Endo which paralleled the changes in the histology of the tissue. At 5 min of coronary occlusion, Ca2+ binding and Ca2+-ATPase activities of SR from ischaemic Endo were normal. A decrease in the activities of SR was first evident at 15 min after the occlusion, decreased further at about 30 min and remained at that level at 60 min of ischaemia. The maximal rate of Ca2+ uptake did not parallel the Ca2+-binding and Ca2+-ATPase activities. The degree of cAMP-dependent phosphorylation by endogenous and exogenous protein kinase was not different between SR from control and ischaemic areas. A participatory role of SR in the ischaemic impairment of left ventricular systolic and diastolic performance is discussed.     

Gas exchange and metabolic transients in heart transplant recipients

In human heart transplant recipients (HTR) an impairment of the cardiac function was expected to reduce peak oxygen consumption and the kinetics of the adjustment of respiratory gas exchange at the onset of rectangular work loads. In nine patients (males, 23-59 yr) 1 to 8 months after cardiac transplantation average peak VO2 (VO2p) was 1.1 L.min-1 +/- 0.3 (SD), i.e. 45% of that of the controls, the corresponding VCO2p value being 1.4 L.min-1 +/- 0.3 (SD). Mean VEp was 62.9 L.min-1 +/- 20.3 (SD), mean HRp was 136 beats.min-1 +/- 11 (SD), i.e. 45 beats.min-1 higher than preexercise values. Mean [Lab]p was 7.7 mM +/- 1.7 (SD), indicating that at the heaviest load the HTR were performing work at or above their maximum aerobic power. During the initial 60-90 sec of the transition from rest to graded rectangular exercise HR did not change from the resting value, increasing thereafter almost linearly with time. The half time (t1/2) of the VE on-response was 112 sec +/- 30 (SD) (controls values: 59 sec +/- 16), that of the VCO2 on- was 95 sec +/- 18 (SD) (58 sec +/- 11), and that of the VO2 on- was 78 sec +/- 24 (SD) (38 sec +/- 6). In spite of the slow kinetics of the VO2 on- response, no massive accumulation of lactate was found in the early phase of exercise. The limitation of the peak exercise in HTR appears to be imposed by a reduced maximal cardiac performance. The slow readjustment of the latter, as expected from the sluggish heart rate response, however, does not impair substantially the work load transients nor reduce the anaerobic threshold.     

HIV-1 matrix protein p17 enhances the proliferative activity of natural killer cells and increases their ability to secrete proinflammatory cytokines

We investigated the effects of human immunodeficiency type-1 virus (HIV-1) matrix protein p17 on freshly isolated and purified human natural killer (NK) cells. HIV-1 p17 increased the cytokines interleukin (IL) 2, IL-12 and IL-15, and induced natural killer cell proliferation, but not cytotoxicity. This effect was specific because it was abrogated by anti-p17 monoclonal antibody. Moreover, HIV-1 p17 enhanced the cytokine-induced production of tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma by NK cells. IL-4 downregulated IFN-gamma and TNF-alpha secretion in IL-2- and IL-15-treated NK cells. HIV-1 p17 restored the ability of NK cells to produce both cytokines when added to the cultures simultaneously with IL-4. The property of p17 to increase the production of TNF-alpha and IFN-gamma might be a mechanism used by HIV-1 to modulate the immune system to support its replication and spreading.     

Juvenile chronic arthritis and imaging: comparison of different techniques

OBJECTIVE: The aim of this study was to compare imaging findings obtained with different techniques in a patient with juvenile chronic arthritis. METHODS: The patient was a 12 years-old child with a 7-months history of arthritis of the first metatarsophalangeal joint of the right foot. The involved area was explored with the following imaging techniques: X-ray, technetium bone scintigraphy, magnetic resonance, gray-scale and power-Doppler ultrasonography. RESULTS: No abnormalities were detected with conventional X-ray. Scintigraphy showed an abnormal uptake of the radionuclide in the first metatarsophalangeal joint of the right foot. Magnetic resonance without contrast revealed clearly evident features of an active process of synovitis. Ultrasonography was able to detect the presence of joint effusion, synovial proliferation, bone erosion of the first metatarsal head. Power-Doppler examination revealed evident signs of soft tissue hyperaemia. CONCLUSIONS: Comparative assessment of different imaging techniques in this patient with recent-onset juvenile chronic arthritis indicates that high resolution ultrasonography provides the most detailed evaluation of the joint involvement with respect to the other imaging techniques.     

Inhibitors of interleukin 1 activity in synovial fluids and in cultured synovial fluid mononuclear cells.

Measurement of interleukin 1 (IL-1) in synovial fluids (SF) yielded variable results and implied the presence of an inhibitory activity. As peripheral blood monocytes produce an IL-1 receptor antagonist (IL-1ra), we investigated whether SF mononuclear cells (SFMC) also secreted such inhibitory activity. MC isolated from inflammatory SF produced, in addition to variable levels of IL-1, a specific IL-1 inhibitor of approximately 23 kDa which blocked both IL-1 biological activity and binding to its receptor. Western blot, using a polyclonal antibody to rhIL-1ra, indicated that SFMC secreted material that shared immunological crossreactivity with the cloned IL-1ra. IL-1 inhibitory activity was also detected in SF but not formally demonstrated to be related to IL-1ra. In conclusion, SFMC could produce IL-1ra and an imbalance between IL-1 and its specific antagonist may be relevant to the severity of joint destruction.     

Intralesional therapy in carpal tunnel syndrome: a sonographic-guided approach

OBJECTIVE: The aim of this pictorial essay is to show a representative example of sonographic-guided injection in carpal tunnel syndrome associated with tenosynovitis of the finger flexor tendons. METHODS: Images were obtained using a real-time ultrasound system (AU4-idea; Esaote Biomedica, Genoa, Italy) equipped with a 13-MHz linear transducer. The best injection site was detected using a fine metal clip placed between the skin and the transducer. The images here were obtained in a patient with rheumatoid arthritis and carpal tunnel syndrome secondary to tenosynovitis of the finger flexor tendons. RESULTS: Steroid injection within the carpal tunnel under sonographic control was easily performed. All steps of the needle placement within the widened tendon sheath were carefully evaluated on the monitor screen. Marked clinical improvement occurred shortly thereafter (3 days) and increased over the next 6 weeks. CONCLUSION: A detailed assessment of the carpal tunnel and a correct, safe placement of the needle for steroid injection can be quickly performed under sonographic guidance.     

Autonomic cardiovascular alterations as therapeutic targets in chronic kidney disease

Clinical Autonomic Research - The present paper will review the impact of different therapeutic interventions on the autonomic dysfunction characterizing chronic renal failure. We reviewed the...