The use of laser-light scattering and controlled shear in platelet aggregometry

Laser-light scattering was used to observe and quantify the dynamics of human blood platelet aggregation in platelet-rich plasma (PRP). Aggregation was performed in a controlled shear environment by placing the PRP in the annular space between a rotating cylindrical rod and a stationary cylindrical tube. The instrument was capable of very sensitive continuous semi-quantitative measurements of chemically-induced microaggregation. As a demonstration of the technique, results are presented for ADP-induced aggregation at doses of 10, 1, and 0.1 microM and collagen-induced aggregation at a dose of 5 micrograms/ml, each at shear rates of 1,000 s-1 and 500 s-1. Extensive aggregation was observed in response to ADP at even the low dose of 0.1 microM, indicating a high sensitivity to microaggregates. The sensitivity of the ultimate size of the ADP-induced aggregates to ADP concentration was shear dependent. The formation of microaggregates by collagen stimulation was shown to be almost immediate, as contrasted with a 10-20 s typical lag when observed turbidometrically. Disaggregation was observed with 1 microM ADP, but this was only partial, as contrasted with the complete recovery of transmittance observed in the turbidometric technique. Electronic particle sizing and counting was employed to semiquantitatively verify the aggregate size distributions found from mathematical conversion of the laser-light scattering data.     

Secondary cerebral amebiasis due to infection with Entamoeba histolytica. A case report with computer tomographic findings

The clinical and serological findings and computer tomographic (CT) appearances of a case of secondary cerebral amebiasis due to Entamoeba histolytica are presented. The effect of therapy on the neurological symptoms as well as on the CT findings are described in detail. The multiple intracerebral lesions resolved almost completely and the patient survived without any neurological sequelae.     

Obstructive sleep apnoea due to a dermoid cyst of the floor of the mouth.

A case of obstructive sleep apnoea is reported that was caused by a dermoid cyst of the floor of the mouth and cured by surgery.     

Cooling improves the writing performance of patients with writer's cramp.

Cooling of hand and forearm muscles by immersion in 15 degrees C cold water for 5 minutes improved the writing performance of patients with writer's cramp. Since abnormal processing of muscle spindle afferent discharges contributes to the pathology of writer's cramp, this effect might result from a reduction in muscle spindle activity by lowering muscle temperature. Cooling is a simple, cheap, and safe procedure, providing temporary relief for patients with writer's cramp.     

"Cataplexy" and muscle ultrasound abnormalities in Coffin-Lowry syndrome.

The Coffin-Lowry syndrome is a rare cause of mental retardation recognised by its distinctive facial and digital features. We have observed an unusual, non-epileptic, cataplexy-like phenomenon in three subjects with the syndrome and we speculate that this feature may go unrecognised. We also provide evidence of neuromuscular dysfunction as part of the phenotype by showing abnormalities on muscle ultrasound in four gene carriers.     

Effect of imipramine treatment on heart rate variability measures.

Recently, heart rate (HR) variability has received considerable attention, and a decreased HR variability has been linked to a significant risk of cardiovascular illness. We have previously reported such a decreased variability in panic disorder patients. In this study, we report on HR variability in 12 depressed and 6 panic disorder patients at baseline and 1 and 3 weeks of treatment with imipramine as measured by the standard deviation, mean consecutive difference and the standard deviation of the mean consecutive difference of the R-R intervals in supine, supine deep breathing and standing postures. In all subjects, imipramine (mean dose: 70 mg/day) produced a significant decrease in heart rate variability at week 3 as measured by the above variables. This decrease in HR variability during imipramine treatment is probably due to its anticholinergic effects.