Myosin light chains and muscle pathology

We evaluated the isoform composition of heavy and light chains of myosin in single muscle fibers from patients with Duchenne dystrophy, myotonic dystrophy, or polymyositis. In all myopathic muscles, there was an increase in the proportion of intermediate fibers which, by analysis of myosin isoforms, fell into two subpopulations, one that contained both fast and slow myosin and another that contained myosin molecular hybrids. The increased proportion of intermediate (or transitional) fibers suggests changes in the equilibrium between fast and slow motor units. These changes could result from regeneration and subsequent maturation of fibers or from direct transformation of mature fibers of one type into the opposite.     

Distribution of normal and abnormal fluid collections in the glenohumeral joint: Implications for MR arthrography

Although magnetic resonance (MR) images of the glenohumeral joint frequently demonstrate intraarticular fluid, no specific criteria have, to the authors' knowledge, been published that allow accurate assessment of the amount of fluid present. Also, despite the increasing use of MR arthrography of the shoulder, the optimal amount of intra-articular fluid that should be used with this technique has not been determined. The authors progressively distended the glenohumeral joint in six cadaveric shoulder specimens with a dilute gadopentetate dimeglumine solution and obtained MR images after injection of 2, 5, 10, 15, and 20 mL of the solution. The pattern of fluid distribution was evaluated, and these results were then used to estimate the amount of fluid that was present in the glenohumeral joint on MR images of 20 shoulders obtained in 12 asymptomatic volunteers. In 14 of these shoulders, intraarticular fluid was present; however, in none was more than 2 mL evident. Results of the cadaveric study also indicated that 15 mL of intraarticular fluid appears to be the optimal amount for MR arthrography.     

Hysteresis of the mammalian pCa/tension relation is small and muscle specific

Summary Small but statistically significant shifts (hysteresis) between the up (increasing tension direction) and down (decreasing tension) pCa/tension relation for several muscle types of the rabbit and rat were found. The largest shift is, at most, 0.093 p units or 60% of that reported for the barnacle muscle. The direction of shift for psoas is opposite to that for the soleus and tibialis.     

Anatomic variations of surgical importance in ethmoid labyrinth and sphenoid sinus. A study of radiological anatomy

Summary The present study was performed on axial and coronal CT scans of 100 patients, most of whom were affected by nasal polyposis. Five observers had to analyse the radiograms and answer a questionnaire including the following items: presence of a supraorbital recess; identification of anterior and posterior ethmoidal canals; dehiscences in the lamina papyracea; pneumatized middle turbinate; presence of a spheno-maxillary plate; presence of Haller's cells; presence of Onodi's cells; relationships of the optic canal; relationships of the internal carotid artery; relationships of the maxillary nerve; relationships of the vidian nerve; level difference between the ethmoid roof and nasal vault; depth of the sphenoethmoidal recess. The data obtained were compared with those drawn from anatomical studies. The fair agreement between them proves the value of CT as an alternative method for studying paranasal sinuses anatomy.

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Anatomie radiologique des variations du labyrinthe ethmoïdal et du sinus sphénoïdal et leurs conséquences chirurgicales

Résumé Cette étude a été réalisée sur 100 patients dont la plupart présentait une polypose nasale étudiée en coupes T D M axiale et coronale. Cinq lecteurs ont revu les clichés et répondu au questionnaire suivant: présence d'un récessus supra orbitaire; identification des canaux ethmoïdaux antérieur et postérieur; déhiscence de la lame papyracée; pneumatisation du cornet moyen; présence d'un plateau sphéno maxillaire; présence de cellules de Haller; présence de cellules d'Onodi; rapports du canal optique; rapports de l'artère carotide interne; rapports du nerf maxillaire; rapports du nerf vidien; dénivelé entre le toit ethmoïdal et le toit nasal; profondeur du récessus sphéno-ethmoïdal. Les données obtenues ont été comparées avec celles provenant de travaux anatomiques. La concordance acceptable entre les deux démontre la valeur du scanner comme méthode d'étude alternative de l'anatomie des sinus para nasaux.

     

Association of microneme antigens of Plasmodium brasilianum merozoites with knobs and other parasite-induced structures in host erythrocytes.

The localization of Plasmodium brasilianum antigens, common to merozoite micronemes and parasite-induced structures in the host erythrocyte, was determined by means of immunogold electron microscopy and monoclonal antibodies directed against blood stages of this parasite. All monoclonal antibodies reacted with micronemes. In addition, some reacted with either knob protrusions or caveolae of the host erythrocyte membrane; one reacted with a parasite-derived antigen present in the erythrocyte cytoplasm. Gold particles appeared over the membranes of ring-infected cells before the appearance of knobs and caveolae. We hypothesize that at least some knob- and caveolae-associated antigens of P. brasilianum are inserted into the erythrocyte membrane at the time of merozoite invasion.     

Design and rationale for novel antifolates

The goals of new antifolate development are: 1) improved selectivity, 2) improved penetration into pharmacologic sanctuaries, and 3) effectiveness vs. tumors either with intrinsic or acquired resistance to methotrexate (MTX). The major target for antifolate development has been dihydrofolate reductase (DHFR), but other critical folate-dependent enzymes, i.e., thymidylate synthase, methionine synthetase, and folylpolyglutamate synthetase are also important targets for new antifolate development. The possibility that DHFR from tumor tissue differs significantly from normal tissue DHFR now seems improbable, and the ideas of the late Bill Baker to design specific inhibitors of the tumor enzyme vs. the normal tissue DHFR are unlikely to succeed. However, the experience with triazinate (Baker's antifol; TZT) indicates that transport of antifols could be exploited to provide selective toxicity, as well as to provide agents effective vs. MTX-resistant cells. This work led to a second generation of "nonclassical" folate antagonists, of which trimetrexate (JB-11; TMQ) is now in clinical trial. Uptake of TMQ is via an MTX-independent membrane system, and extremely high intracellular levels of this drug are achieved in human leukemia cells.     

Surgical treatment of toxic adenoma

In the period ranging from 1985. to 1994. a total number of 86 patients have been treated for toxic adenoma (TA). Hyperthyroidism was more often present in males (70.83% versus 51.61%) and in enlarged adenomas (more then 2 cm in diameter). Pathohistologic type of adenoma influenced degenerative changes. Three carcinoma have been observed, two papillary and one follicular. Surgical treatment is the method of choice. Complications are rare (3.49%) and mild.     

Role of nimodipine in the therapy of subarachnoid and intracerebral hemorrhage

Syndromes of intracranial hemorrhage, and particularly subarachnoidal, i.e., intracerebral hemorrhage (SAH and IH) present clinical entities that are the most severe conditions in neurology. Timely recognition, diagnosis and adequate therapy are imperative. The most important factor that aggravates an already difficult prognosis of those entities is cerebral vasospasm. Upon the presented facts, the aim of this investigation was to establish the value and role of administration of selective calcium channel blocker--nimodipine in patients with SAH and IH compared to the degree of neurological and functional impairment, as well as the recovery of the function of consciousness compared to the patients with those syndromes from an earlier period, who were not treated with this medicament. Investigation comprised 30 patients who received nimodipine and 20 patients without this agent in therapeutic program. Results of the investigation confirmed significant difference concerning the neurological recovery, improvement of functional capability and recovery or consciousness disturbances, respectively, in patients who received nimodipine compared to the group without this agent. It can be concluded that nimodipine as calcium channel blocker with multitopic pharmacological effects on mechanism of SAH or IH development, respectively, as well as on the development of complications of those syndromes, particularly to the development of vasospasm and reactive ischemia, with the improvement of hemorrheologic disorders deserves to be included as the unavoidable segment of therapeutic program of SAH and IH syndrome immediately after clinical phenomenology is revealed.     

Concentration-effect relationship for antimicrobial drugs

The many relevant pharmacokinetic aspects influencing the relationship between antimicrobial drug concentration in the blood and at infection site with their pharmacodynamic effects are discussed, with particular regard to rules upon which clinical treatment modalities are based.     

Multicenter Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Study for Identification of Clinically Relevant Nocardia spp.

This multicenter study analyzed Nocardia spp., including extraction, spectral acquisition, Bruker matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) identification, and score interpretation, using three Nocardia libraries, the Bruker, National Institutes of Health (NIH), and The Ohio State University (OSU) libraries, and compared the results obtained by each center. A standardized study protocol, 150 Nocardia isolates, and NIH and OSU Nocardia MALDI-TOF MS libraries were distributed to three centers. Following standardized culture, extraction, and MALDI-TOF MS analysis, isolates were identified using score cutoffs of ≥2.0 for species/species complex-level identification and ≥1.8 for genus-level identification. Isolates yielding a score of <2.0 underwent a single repeat extraction and analysis. The overall score range for all centers was 1.3 to 2.7 (average, 2.2 ± 0.3), with common species generally producing higher average scores than less common ones. Score categorization and isolate identification demonstrated 86% agreement between centers; 118 of 150 isolates were correctly identified to the species/species complex level by all centers. Nine strains (6.0%) were not identified by any center, and six (4.0%) of these were uncommon species with limited library representation. A categorical score discrepancy among centers occurred for 21 isolates (14.0%). There was an overall benefit of 21.2% from repeat extraction of low-scoring isolates and a center-dependent benefit for duplicate spotting (range, 2 to 8.7%). Finally, supplementation of the Bruker Nocardia MALDI-TOF MS library with both the OSU and NIH libraries increased the genus-level and species-level identification by 18.2% and 36.9%, respectively. Overall, this study demonstrates the ability of diverse clinical microbiology laboratories to utilize MALDI-TOF MS for the rapid identification of clinically relevant Nocardia spp. and to implement MALDI-TOF MS libraries developed by single laboratories across institutions.