Sufentanil does not increase cerebral blood flow in healthy human volunteers

The effect of sufentanil on human cerebral blood flow (CBF) was studied in seven unpremedicated, healthy volunteers 31 +/- 3.5 yr of age (mean +/- SD) and either sex. CBF (ml.100 g-1.min-1) was measured noninvasively with the 133Xe clearance technique and a scintillation camera before and after sufentanil 0.5 micrograms/kg administered intravenously. This technique provides values for global blood flow and for gray and white matter blood flow, and from 13 preselected regions in one hemisphere. After the administration of sufentanil, the volunteers were stimulated verbally in order to prevent their loss of consciousness and hypercarbia. Heart rate (HR), arterial pressure, oxyhemoglobin saturation, and end-tidal CO2 (ETCO2 were recorded during the measurements. Neither global CBF (46.1 +/- 1.6 control and 43 +/- 1.9 after sufentanil, mean +/- SEM) nor gray (76.5 +/- 3.2 and 70.9 +/- 6.1) or white (22.7 +/- 1.5 and 24.2 +/- 1.6) matter blood flow changed significantly after sufentanil administration. As well, no significant differences in HR (72 +/- 4 control and 79 +/- 4 beats per min after sufentanil) and ETCO2 (39.8 +/- 1.4 and 41.1 +/- 1.1 mmHg) were observed. It is concluded that sufentanil has no significant effect on CBF in healthy human volunteers.     

Alterations at the rel locus in human lymphoma.

The rel proto-oncogene has been mapped to chromosome region 2p11.2-14, a site associated with nonrandom rearrangements in non-Hodgkin's lymphoma. We have characterized an abnormal rel mRNA from a cell line derived from a diffuse large cell lymphoma, in which the evolutionarily conserved N-terminal half of the rel coding region was fused with the C-terminal coding region of an unrelated gene. In addition, rearrangement or amplification of the rel locus was found in the lymphomatous tissue of two follicular and one diffuse large cell lymphoma. The findings suggest involvement of rel in the pathogenesis of large cell lymphoma.     

Test for kidney hemorrhage following exposure to intense, pulsed ultrasound

A recent study has found that the threshold for extravasation in mouse kidney tissues by exposure to a spark-generated shock wave is of the order of 3-5 MPa (peak positive pressure). Since the mode pressure used by commercial pulsed Doppler ultrasound units is approximately 5 MPa, it is essential to determine whether these observations are relevant to diagnostic ultrasound. Hence, a comparable study has been completed using the same pathological endpoints but with exposure to pulsed ultrasound (10 microseconds pulse length) at 1.2 MHz and 3.8 MHz in which peak positive pressures exceeded 10 MPa. At these levels the focal waves are in shock because of the nonlinear properties of the propagating medium. The results of the pulsed ultrasound study were negative. Although this finding is encouraging for the use of diagnostic ultrasound, the two studies eventually must be integrated into a single mechanistic picture before the limits of safety will be known.     

Electrophysiologic effects of the calcium antagonist isradipine, a double-blind placebo controlled study

The electrophysiologic effects of the calcium channel antagonist isradipine (0.5 mg) in comparison to placebo were evaluated in a double blind study with nine patients in two groups. The patient groups were not different in respect to the underlying cardiac disease, electrophysiologic parameters at the baseline study, or in blood pressure. Isradipine significantly decreased the systolic (p less than 0.01) and diastolic (p less than 0.05) blood pressure, while sinus cycle length decreased significantly (p less than 0.05) in the placebo group and the isradipine group with no difference between the two study groups. The influence on sinus node recovery time, effective refractory period of the av-node, intranodal conduction time, and PR interval were not significant. In conclusion, isradipine significantly decreased systolic and diastolic blood pressure. The decrease in sinus cycle length after intravenous isradipine was not significantly different from the decrease seen in the placebo group. Atrioventricular conduction was not significantly affected.     

Comparison of 6 and 8 hourly tobramycin dosing intervals in treatment of pulmonary exacerbations in cystic fibrosis patients

The efficacy and toxicity of a shortened tobramycin dosing interval in the treatment of exacerbations of Pseudomonas aeruginosa pulmonary infection in cystic fibrosis patients were evaluated prospectively. Patients ages 13 to 30 years received 34 treatment courses and were randomized by pairs to receive tobramycin administered either every 6 or 8 hours. Peak serum concentrations were adjusted to 8 to 10 micrograms/ml; thus a larger total daily dosage was administered to patients receiving tobramycin every 6 hours. The shorter dosing interval was associated with better pulmonary function at follow-up and significantly longer time before next hospital admission for a pulmonary exacerbation. During the study hospitalization there were no differences in pulmonary function tests, clinical score, sputum carriage of P. aeruginosa, toxicity or necessary length of hospitalization. A 6-hour tobramycin dosing interval was more efficacious than an 8-hour dosing interval in the treatment of cystic fibrosis patients.     

The effect of basic fibroblast growth factor and omentopexy on revascularization and epithelial regeneration of heterotopic rat tracheal isografts.

Donor airway ischemia is a significant problem after clinical lung transplantation despite the use of omentopexy for accelerated local bronchial revascularization. Several growth factors have been shown to induce angiogenesis in vitro and in vivo. In the present study the quantitative effects on tracheal revascularization and epithelial regeneration of omentopexy and continuous local administration of basic fibroblast growth factor were investigated in a heterotopic rat tracheal isograft model. Tracheas were harvested from donor rats and heterotopically implanted into the omentum of syngeneic recipient rats. Animals were randomly assigned to study groups differing only in treatment of the tracheal segments: omental wrap for 2, 7, or 14 days; omental wrap plus continuous local administration of basic fibroblast growth factor for 7 or 14 days; or omental wrap plus local application of saline for 7 or 14 days. Two, 7, or 14 days after the animals were put to death, the vascularity of the tracheal segments and attached omentum and the tracheal epithelial morphology were assessed in a blinded fashion with use of light microscopy and morphometric image analysis. Vascularity in tracheal segments treated with basic fibroblast growth factor was significantly (p less than 0.05) greater than in control tracheas after 7 and 14 days. Epithelial regeneration was also improved in the basic fibroblast growth factor-treated groups at days 7 and 14 (p less than 0.05). We conclude that continuous local administration of basic fibroblast growth factor enhances early revascularization of tracheal segments induced by omentopexy and accelerates epithelial regeneration in a heterotopic rat tracheal isograft model.     

A new method for measuring the Faradic resistance of a single electrode-electrolyte interface.

A new method is described for measuring the Faradic resistance of a single electrode-electrolyte interface. The method employs a test (monopolar) electrode, a potential-sensing electrode and a large reference (indifferent) electrode, along with a constant-current source capable of providing a step function of current. The method was used to measure the Faradic resistance of a 0.1 cm2 platinum electrode in contact with saline (p = 150 ohm-cm) at room temperature. It was found that for both a positive and negative current pulse, the Faradic resistance decreased almost hyperbolically with increasing current density. When the reciprocal of the Faradic resistance (Gf) was plotted versus current density and the data were fit to a polynomial curve, the results showed that for the positive pulse Gf = 0.009 + 0.05J - 0.0001J2; (SEE = 0.117); for the negative pulse, Gf = 0.007 + 0.067J - 0.0001J2; (SEE = 0.028); where Gf is in millisiemens and J is in mA/cm2 for this 0.1 cm2 electrode. These relationships permit estimating the Faradic resistance (Rf) for zero current density. For the positive pulse, Rf = 111 kilohms and for the negative pulse Rf = 143 kilohms. The method is applicable to the measurement of the Faradic resistance of a wide variety of metal electrodes.     

Free microsurgical latissimus dorsi muscular flaps in swine. In-vitro model for the experimental continuous development of microsurgical reconstruction in the head-and-neck area

An in-vitro system for research into microsurgical transfer technology in head and neck reconstruction is presented for the first time: the free, muscular latissimus-dorsi-flap of the pig. This in-vitro-system is useful for training in microsurgical techniques, for biomechanical tests of vascular connections, and for the simulation of extracorporal circulatory systems in free flaps. This in-vitro system corresponds to human surgical conditions and anatomical proportions. It helps reduce the number of animals needed in microsurgical research and therefore complies with present legislation. The article outlines the surgical technique of raising and replanting the free flap and its cold storage.     

Exposure of human lung fibroblasts to ozone: cell mortality and hyaluronan metabolism.

Exposure of cultures of human lung fibroblasts to 0.5 ppm ozone for 20 h resulted in a significant increase in cellular mortality by 29%; after exposure to 2.5 ppm ozone for 4 h, the increase amounted to 74%. A marked difference in sensitivity to ozone was observed between fibroblast lines from different individuals. This variability in resistance to ozone was more evident after exposure to 0.5 ppm ozone for 20 h, when compared with 2.5 ppm ozone for 4 h. In one fibroblast line, synthesis of hyaluronan was enhanced by exposure to 0.5 ppm ozone for 20 h. The concentrations of hyaluronan in culture media increased in experiments using different fibroblast cell lines, a phenomenon that was obvious both if cell numbers and combined protein concentrations of cells and media are selected as references for hyaluronan concentrations.