Intraoperative arterial occlusion in total joint arthroplasty

This report illustrates a calcified leiomyoma of deep soft tissue in the left leg of a 6-year-old boy. The tumour was composed of spindle cells arranged in interlacing bundles, between which were multiple small and large areas of calcification. Tumour cells were positive for vimentin, desmin and smooth muscle actin. Ultrastructurally, the cells showed numerous pinocytotic vesicles and bundles of intracytoplasmic filaments with smooth muscle dense bodies. Only four calcified leiomyomas have been previously reported in the deep soft tissues of limbs. Here we report a new case and suggest a new pathogenetic scheme involving alkaline phosphatase in the origin of these calcifications.     

Thoracolumbar burst fracture. A biomechanical investigation of its multidirectional flexibility

Assessment of clinical instability of thoracolumbar burst fractures remains controversial and subjective. The purpose of the study was to obtain objective measures of acute instability of these fractures. Thirteen fresh cadaveric human spine specimens (T11-L1) were subjected to high-speed axial trauma, resulting in burst fractures in 10 specimens. Multidirectional flexibilities were measured when the specimen was intact and after the trauma. The average ranges of motion of the burst fractures, measured as percentages of the corresponding intact values at 7.5 Newton-meters, were 202%, 403%, 266%, and 462% for flexion/extension, axial rotation, lateral bending, and tension/compression, respectively. For the neutral zone motion parameter, the motions of the burst fracture were even greater: 670%, 1650%, 779%, and 650%, respectively. All of the increases were significant (P < 0.05). The clinical significance of the study lies in its finding of high multidirectional acute instability of the thoracolumbar burst fracture, especially in axial rotation.     

Production and characterization of monospecific adult worm infections of Strongylus vulgaris and Strongylus edentatus in ponies

Since 1978, 20 surgical implantations of either Strongylus vulgaris or Strongylus edentatus have been performed in our laboratory for the purpose of obtaining single species cultures of these parasites. Following surgical implantation peak EPG values of 13-327 (S. vulgaris) and 363-1284 (S. edentatus) generally occurred during the first 3 weeks post-implantation. Duration of infections was as long as 5 years. Successful outcome of such surgeries appears to be related to the total number of parasites used (> or = 38) and the ratio of female to male worms implanted (1:1 or 2:1).     

Randomized comparison of two schedules of fluorouracil and leucovorin in the treatment of advanced colorectal cancer

The authors report on a case of trisomy 9 mosaicism syndrome, a rare chromosome abnormality. The common features of this syndrome are growth and mental retardation, low-set malformed ears, wide sutures and fontanelles, bulbous nose, short palpebral fissures, micrognathia, microphthalmia and enophthalmos, abnormal hands and feet, hip dislocation, joint limitation, cardiovascular defects and urogenital abnormalities. Our patient presented some unusual characteristics, such as 13 pairs of ribs, a vertebral malformation, a hemivertebra and a Dandy-Walker syndrome. They compare their clinical findings with the few cases previously described and they try to contribute to the further clinical definition of the syndrome. It is possible that there is a correlation between the variability of the phenotype and the percentage of trisomic cells in the patient.     

Degenerate perturbations of protein structure as the mechanism of anaesthetic action

The interaction of the n-alkanols with lipid bilayers and excitable membranes shows that there is no simple correlation between conduction block and any of the perturbations of bilayer structure currently proposed as unitary mechanisms of local anaesthetic action. We propose instead that the n-alkanols act by direct interaction with target proteins to cause perturbations which depend directly on the precise structure of the alcohol.     

The ''in vitro'' effect of diethylcarbamazine on the motility and survival of Onchocerca volvulus microfilariae

This paper presents a tested approach to a systematic progression of learning from the classroom to the clinical internship. The approach uses workbooks to integrate all facets of the training continuum. The basic model is training continuum. The basic model is called TAR. T refers to theory or teaching; A to application, which occurs during the clinical component; and R to reinforcement provided through seminars scheduled concurrently with fieldwork. The entire concept is introduced to students during a required weekly fieldwork preparation component scheduled prior to the first theory course. Clinicians and academicians participated in all phases of the three-year, HEW-funded project, which included development of interrelated performance objectives for the teaching, application and reinforcement components. Analysis of data from clinicians, students and faculty indicated that the TAR model provides a needed integrating structure.     

A difference in the rate of ribosomal elongation balances the synthesis of eukaryotic translation initiation factor (eIF)-2 alpha and eIF-2 beta

Eukaryotic translation initiation factor 2 (eIF-2) is a heterotrimer composed of three subunits designated alpha, beta, and gamma. These proteins exist in equimolar amounts in the cell and have not been detected as isolated subunits. Our research examines the basis of their balanced synthesis. Northern analysis of K562 cell mRNA revealed that eIF-2 beta was five times more abundant than eIF-2 alpha. However, immunoprecipitation of pulse-labeled K562 cells showed an equimolar rate of synthesis of eIF-2 alpha and -beta despite the 5-fold difference in the size of their mRNA pools. Addition of equal amounts of synthetic capped mRNA for eIF-2 alpha and eIF-2 beta to an in vitro translation reaction produced five times more eIF-2 alpha protein than eIF-2 beta. Determination of the polysome profile for alpha and beta mRNA in K562 cells indicated eIF-2 alpha was translated more efficiently than eIF-2 beta. Substitution of either the initiation codon context or the leader of the beta mRNA for that of alpha had only a minor effect on the translational efficiency of beta. Comparison of the rate of ribosomal elongation for the two mRNAs indicated that ribosomes associated with the beta mRNA elongate at a rate 4-fold less than that of eIF-2 alpha. Thus, the balanced translation of alpha and beta mRNA is primarily the result of a 4-fold difference in the rate of ribosomal elongation.