Photogrammetric analysis of the articular surface of the distal radius

Three-dimensional measurements made using photogrammetry have recently gained popularity with the development of real-time detection facilities and up-to-date equipment. The modelling of human bones presents a particular challenge as the measurements required are difficult to obtain, especially from uneven surfaces. In this study, the articular surfaces of 12 radius bones were evaluated using photogrammetry to obtain three-dimensional coordinates of certain points. Morphometric characteristics of the digital topography of the articular surface were analysed using three-dimensional data from more than 200 points for each specimen. The coronal plane curve, from the tip of the styloid process to the centre of the distal radioulnar articular notch, was found to be similar to the fourth degree polynomial function. A mathematical expression representing the sagittal curve passing through scapholunate border could not be found. Close-range photogrammetry is a safe and precise technique that can provide reliable, reproducible and accurate data for evaluating complex morphological surfaces.

Flexor tendon injuries of children in zone 2 (FDS repair or not)

Twenty flexor tendons in 13 children with a mean age of 7 years old (range from 9 months to 14 years) were treated by primary suture between 1994-1999. Both tendons were repaired in 12 (60%) digits and only FDP in 8 (40%) with excision of FDS. Mean follow-up was 19 months (from 6 to 55 months). In the 12 fingers with FDS repair, the results were excellent in 2, good in 4, fair in 3 and poor in 3. In the 8 fingers with FDS excision, 2 rated excellent, 5 good and 1 poor. In conclusion, repair of FDP alone with regional excision of FDS simplifies the operative procedure and reduces the number of tendon sutures inside the sheath.

Reconstruction of chronic collateral ligament injuries to fingers by use of suture anchors

AIM

To evaluate the effectiveness of suture anchors in the reconstruction of chronic collateral ligaments of fingers.

METHODS

We treated 8 patients, 6 with chronic instability of the collateral ligament of the thumb and 2 with the instability of the fifth finger, using the Statak suture anchor. A stable joint was achieved in each case, with no recurrent instability or pain within a mean of 14 months of the follow up.

RESULTS

Postoperatively, each patient returned to his or her original job, their daily activities, and sports. There was no significant difference on manual stress testing measurements between operated and uninjured fingers. Mean pinch strength and range of motion were 90% (range, 78-104%) and 94% (range, 70-100%), respectively, compared to uninjured fingers.

CONCLUSION

Suture anchor technique can be recommended as a simple and effective method of repairing the collateral ligament of fingers.

Signaling by human herpesvirus 8 kaposin A through direct membrane recruitment of cytohesin-1

The induction of a transformed cellular phenotype by viruses requires the modulation of signaling pathways through viral proteins. We show here that the phenotypic changes induced by the kaposin A protein of human herpesvirus 8 are mediated through its direct interaction with cytohesin-1, a guanine nucleotide exchange factor for ARF GTPases and regulator of integrin-mediated cell adhesion. Focus formation, stress fiber dissolution, and activation of the ERK-1/2 MAP kinase signal cascade were reverted by the cytohesin-1 E157K mutant, which is deficient in catalyzing guanine nucleotide exchange. Furthermore, liposome-embedded kaposin A specifically stimulates cytohesin-1 dependent GTP binding of myristoylated ARF1 in vitro. These results suggest a previously unknown involvement of ARF GTPases in the control of cellular functions by herpesviruses.

Rat sperm enzymes during epididymal transit

The activities of cAMP and cGMP phosphodiesterases (EC 3.1.4.1), adenylate cyclase (EC 4.6.1.1) and protein carboxyl-methylase (EC 2.1.1.24) were measured in the particulate and soluble (105 000 g supernatant) fractions of washed spermatozoa isolated from five segments of the adult rat epididymis. The activities of both phosphodiesterases decreased during epididymal transit, whereas adenylate cyclase and protein carboxyl-methylase underwent a progressive increase, the latter showing the most marked alteration. Both cAMP and cGMP phosphodiesterases as well as the adenylate cyclase were all associated primarily with the particulate fraction, and the extent to which these enzymes were associated with the membranes increased as the spermatozoa passed through the epididymis. Sperm protein carboxyl-methylase activity was, on the other hand, predominantly soluble in all segments of the epididymis. Adenylate cyclase, cAMP phosphodiesterase and protein carboxyl-methylase activities were found predominantly in the sperm tails, whereas cGMP phosphodiesterase was equally distributed between heads and tails. These observations imply that the acknowledged increase in intracellular cAMP levels which occurs in spermatozoa during epididymal transit may be a consequence of both increased synthesis (adenylate cyclase) and reduced hydrolysis (phosphodiesterase).

Fallout Plutonium in an Alkaline, Saline Lake

Plutonium isotopes, derived from global fallout following atmospheric testing of nuclear weapons, have been measured in the water and sediments of a natural alkaline, saline lake. The activities of fallout plutonium in the water column are about two orders of magnitude greater than in most freshwater lakes, where these nuclides are found predominantly in the sediments.