Simultaneous in vivo measurement of lumped constant and rate constants in experimental cerebral ischemia using F-18 FDG

Lumped and transfer rate constants in ischemic brain tissue must be measured to estimate accurately cerebral glucose utilization by the deoxyglucose method. We studied the bilateral middle cerebral artery occlusion model in 17 cats, 5 with a 1-hour occlusion, 5 with a 4-hour occlusion, and 7 with a sham operation. The time course of cerebral tissue radioactivity (Ci*(t)) was monitored by external coincidence counting during a programmed infusion of [18F]-2-deoxy-2-fluoro-d-glucose (18F-2-FDG). Arterial plasma concentration (Cp*(t)) of the tracer was kept constant during the first 45 minutes. Rate constants were estimated from Ci*(t) and Cp*(t) by a nonlinear least-squares fitting routine. The lumped constant was estimated from the fit of the ratio of extraction fractions of glucose and 18F-2-FDG by nonweighted, nonlinear least-squares fitting. In the 4-hour-occlusion model, the transfer constant k1* was 23% lower, k3* 39% lower, and the lumped constant 78% higher than in the sham-operated animals. In the 1-hour-occlusion model, k3* was 26% lower than in the sham-operated animals but the lumped constant was not significantly different. The rate of glucose utilization was significantly different in the 4-hour-occlusion model compared to the sham-operated animals (48% decrease, p less than 0.05) but was not significantly different in the 1-hour-occlusion model.     

Subclavian flap aortoplasty with preservation of arterial blood flow to the left arm for coarctation repair--report of 2 cases

Two infants with coarctation of the aorta were successfully repaired by the modified method of subclavian flap aortoplasty with preservation of arterial blood flow to the left arm. The left subclavian artery was detached from the aorta at its origin, opened longitudinally in its posterior wall and sutured over the coarctation site. Widening of the stenosis and preserving of the blood flow to the left arm were obtained. This operative technique seems advantageous without complications induced by sacrificing the continuity of the subclavian artery, reserving the advantages of the former subclavian flap aortoplasty.     

Penetrating keratoplasty and cataract surgery

Of 46 eyes undergoing simultaneous penetrating keratoplasty and cataract extraction, 25 grafts (54%) remained clear with an average follow-up of 37 months. This low success rate can be party explained by the fact that more than 50% of our patients had unfavourable ocular conditions preoperatively. In case of simultaneous procedures, methods of cataract extraction (ICCE or ECCE) did not have any significant affect on the rate of clear grafts. In eyes with favourable ocular conditions preoperatively, the rates of clear grafts were similar (approximately 75%) in cases of simultaneous operation (21 eyes) and separate operation (8 eyes).     

Antigenic and restriction endonuclease analyses of new adenovirus types 19 and 37 causing acute conjunctivitis

DNA restriction endonuclease cleavage analysis and serum neutralization test were performed in strains of adenovirus types 19 (Ad-19) and 37 (Ad-37) isolated from patients with acute conjunctivitis in Sapporo (Japan), Kaohsiung (Taiwan) and Pusan (South Korea) during the period of 1977 to 1984. Ad-19 and Ad-37 could be roughly differentiated, but a fair degree of cross reactivity was noted by serological test. By DNA restriction endonuclease analysis, Ad-19 isolates, Ad-19 prototype strain and Ad-37 strains were clearly differentiated. It was suggested by DNA cleavage patterns that both Ad-19 and Ad-37 isolates in East Asia are the same as those currently found in Europe and the USA. A new subtype of Ad-37 was found by DNA cleavage analysis among the isolates obtained in Sapporo and Kaohsiung in 1980.     

Calcium is essential for both the membrane binding and lytic activity of pore-forming protein (perforin) from cytotoxic T-lymphocyte

The influence of Ca on the membrane binding and lytic activity of lymphocyte pore-forming protein (perforin) was studied. In the absence of Ca, perforin did not bind to the target membranes and did not support lysis of the target cells. In contrast, in the presence of Ca perforin was able to bind to the cell membrane (Km greater than 0.2 mM). Almost all the perforin molecules bind to the membrane within 1 min at 0 degrees C. The addition of EDTA abolished the binding, indicating that the effects of Ca on the membrane binding are reversible. On the other hand, the perforin-mediated lysis of target cells was temp-dependent and also required the presence of Ca in the reaction mixture (Km = 0.05 mM). The difference between the Km values for the membrane binding and lytic activity suggests the presence of two distinct Ca-requiring steps in perforin-mediated target cell lysis.     

Migration of neutrophils is dependent on mast cells in nonspecific pleurisy in rats.

To determine the role of mast cells in the recruitment of neutrophils and eosinophils, acute nonspecific pleurisy was induced by injecting isologous serum into normal +/+ and mast cell-deficient Ws/Ws rats. In +/+ rats, neutrophil infiltration peaked 4 h after serum administration, followed by influx of eosinophils after 24-48 h. The levels of neutrophil influx after 4 h as well as the activity of myeloperoxidase (MPO) in pleural lavage-cell extract were significantly lower in Ws/Ws rats than in +/+ rats. In contrast, numbers of eosinophils as well as activity of eosinophil peroxidase (EPO) did not differ significantly between Ws/Ws and +/+ rats. For local reconstitution of mast cells, +/+ rat peritoneal mast cells (PMC) or mesenteric lymph node cells (MLNC) as a control were transferred into the Ws/ Ws pleural cavity. Serum injection into animals with PMC transfer 7 days previously triggered augmented neutrophil influx by approximately 4.7-fold as compared to that in MLNC-transferred animals. Mast cells recovered from the pleural cavity of PMC-transferred rats showed histamine contents equivalent to 20% of that of freshly isolated PMC and retained the reactivity to compound 48/80. These results indicated that dependency of neutrophil recruitment on resident mast cells is greater than that of eosinophils in isologous serum-induced pleurisy.