Cytokines in synovial fluid. I. The presence of biologically active and immunoreactive IL-1.

Using a sensitive IL-1-dependent T cell clone we estimated interleukin 1 (IL-1)-like activity in a variety of synovial fluids (SF). Although we demonstrate that SF contains potent inhibitors of endogenous and exogenous IL-1 we were able to estimate that samples from rheumatoid arthritis, osteoarthritis and other arthritides contain the equivalent of tens or hundreds of picograms of IL-1 per millilitre, when compared to a standard IL-1 preparation. Although there was some correlation between these results and those obtained using a radio-immunoassay (RIA) for IL-1 beta, the RIA indicated that IL-1 was present in the nanogram range. The results suggest that the importance of inhibitors of IL-1 in SF merits particular attention and that it is also important to consider the bioactivity of cytokines which may be detected by physical methods.     

Catch-up growth up to ten years of age in children born very preterm or with very low birth weight

Background  

Improved survival due to advances in neonatal care has brought issues such as postnatal growth and development more to the focus of our attention. Most studies report stunting in children born very preterm and/or small for gestational age. In this article we study the growth pattern of these children and aim to identify factors associated with postnatal catch-up growth.     

Safety studies with the University of Melbourne multichannel electrotactile speech processor.

Results of safety investigations conducted as an integral part of the development of a multichannel electrotactile speech processor (Tickle Talker) are reported. Electrical parameters of the stimulus waveform, design of the electrode handset and cabling, and the electrical circuitry of the speech processor/stimulator and programming interface have been analyzed for potential risks. Constant current biphasic square pulses delivered to electrodes positioned on the skin surface over the digital nerve bundles were chosen to optimize the safety, comfort, and function of the electrotactile stimulus. The device was battery-powered, and the user circuit was isolated from earth-referenced sources. Each electrode was isolated by capacitive coupling, preventing DC leakage of current to the user circuit. Studies of finger temperature showed slight cooling of the skin on the fingers of both stimulated and unstimulated hands for individual subjects following electrotactile stimulation through the Tickle Talker. Subsequent analysis of finger and hand vascular circulation in five subjects showed slight reductions in hand blood flow in some individuals. The results did not demonstrate a significant mean decrease in hand or finger blood flow following electrotactile stimulation. No evidence of sympathetic involvement was found, nor were any changes in vascular structure of the hand such as those associated with Raynaud's disease found. Evidence suggests that the decrease in temperature found in the initial study may be due to a change in the ratio of blood flow between arteriovenous anastomoses and nutritive capillary beds. Studies of: 1) changes in mean threshold and comfortable pulse widths over time; and, 2) changes in tactual sensitivity as measured by hot/cold, sharp/dull, and two-point difference limen discrimination, did not detect any systematic change in peripheral nervous system function following electrotactile stimulation. Analysis of electroencephalogram (EEG) recordings taken during electrotactile stimulation, and after relatively long periods of experience with the device did not show any pathological changes which might be associated with epileptic foci. In summary, no contraindications to long-term use of the Tickle Talker were detected in the studies performed.     

Electrophysiological properties of in vitro intrinsic cardiac neurons in the pig (Sus scrofa)

Physiological properties and synaptically mediated responses of 34 ganglionated plexus neurons from the right atrium of the pig heart were studied with in vitro intracellular recording techniques. Whole-cell input resistance of these neurons was lower, time constant was shorter and threshold for directly evoked action potentials was higher than the same properties in extracardiac autonomic neurons. Long intracellular depolarizing current pulses (400–500 ms) failed to generate more than one or two action potentials. Nicotinic and non-nicotinic synapses were present on neurons in cardiac ganglia and neuronal properties could be modified by norepinephrine. Based on their physiological properties, cardiac ganglionated plexus neurons in the pig appear to represent a distinct population of autonomic neurons that may be capable of intracardiac integration of efferent information to the heart.     

In vivo proton magnetic resonance spectroscopy of alcohol in human brain

The covariance between blood and brain alcohol levels and subjective reports of mood were examined in 6 healthy adult men after consumption of 0.7 g/kg of beverage alcohol. There was significant (p less than 0.01) temporal concordance between ascending and peak blood alcohol levels and regional brain alcohol levels as measured by in vivo proton Magnetic Resonance Spectroscopy (MRS) when N-acetyl aspartate (N-AA) concentration was used as an internal standard. The frequency of reports of both euphoria and dysphoria also paralleled the ascending limb of the blood and brain alcohol curve. However, peak blood alcohol levels were higher (125.67 +/- 10.91 mg/dl) and earlier (35 min postdrinking) than peak brain alcohol levels (26.25 +/- 6.38 mg/dl) detected 50 min after alcohol intake. This difference in brain and blood alcohol levels appears to be associated with the echo time (TE) parameters of the MRS. A decrease in TE from 270 msec to 50 msec resulted in a marked increase in brain alcohol detectability. MRS measures will permit analysis of regional differences in brain alcohol concentrations and covariance with behavioral, neurophysiologic and neuroendocrine concomitants of acute alcohol intoxication in man.     

Percutaneous cholecystolithotomy

We have successfully removed gallstones percutaneously from the gallbladders in two poor surgical risk patients using the standard equipment and the principles of percutaneous nephrolithotomy. No complication occurred in either patient. A brief review of percutaneous gallstone extraction is presented.     

Independent prognostic significance of a nuclear proliferation antigen in diffuse large cell lymphomas as determined by the monoclonal antibody Ki-67

To assess the prognostic significance of the growth fraction in diffuse large cell lymphoma (DLCL), we studied 105 DLCL patients with the monoclonal antibody Ki-67 applied to frozen tissue sections. Ki-67 detects a nuclear antigen associated with cell proliferation not found in resting cells. Ki-67 findings and other clinical prognostic factors were correlated with outcome using univariate and multivariate analyses in the proportional hazards model. High proliferative activity, defined as nuclear Ki-67 expression in greater than 60% of malignant cells (Ki- 67 greater than 60), was found to be a strong predictor of poor survival among these patients (P = .003, log-rank). The 19 patients with Ki-67 greater than 60% had a median survival of 8 months compared with a median survival of 39 months for the 86 patients with Ki-67 less than or equal to 60%. Examination of pretreatment clinical variables indicated the patient groups were similar with regard to age, sex, stage, B symptoms, tumor bulk, and lactate dehydrogenase (LDH). Both patient groups received comparable curative intent therapy and showed comparable complete response rate precluding treatment differences as modifying outcome. Multivariate analysis indicated Ki-67 is an independent predictor of survival (multivariate P = .006). Further statistical analysis using only B-cell DLCL patients treated with CHOP (63 patients) indicated that Ki-67 greater than 60 retained strong prediction of poor outcome (P = .002, log-rank) among this homogeneous group. We conclude that high proliferative activity (Ki-67 greater than 60) is an independent factor allowing laboratory prediction of probable poor outcome of DLCL.