Movement timing in deaf and hearing speakers: comparison of phonetically heterogeneous syllable strings

We review evidence suggesting that deaf speakers do not move their articulators toward the following open posture throughout closure and report results from a preliminary cinefluorographic study. Two prelingually deaf and two hearing speakers produced two different strings of alternating heterogeneous monosyllables as though speaking in time with a metronome (the so-called P-center task). Events traditionally associated with vowel production appeared evenly timed throughout the productions, and, in general, the deaf speakers performed similarly to the hearing speakers. We relate the results to Fowler's (1983) interpretation of the P-center phenomenon as an indicant of continuous vowel production.     

Elaboration by mammalian mesenchymal cells infected with Trypanosoma cruzi of a fibroblast-stimulating factor that may contribute to chagasic cardiomyopathy.

Myocardial fibrosis can occur as a complication of chronic infection of the heart with Trypanosoma cruzi (Chagas' disease) and can lead to serious disability. To assess whether there might be a direct relationship between intracellular parasitization and subsequent tissue fibrosis in this disease, we tested serum-free conditioned media from cultures of fibroblasts, vascular smooth-muscle cells, and myocardial cells for fibroblast-stimulating activity. Conditioned media from all infected cultures, but not from uninfected cultures, stimulated fibroblast [3H]thymidine incorporation, DNA and protein synthesis, and cell proliferation. Fibroblast-stimulating activity was also detected in extracts of amastigotes but not of trypomastigotes or epimastigotes. We conclude that parasitization of mesenchymal cells, including myocardial cells, results in elaboration of a fibroblast-stimulating factor(s), perhaps of parasite origin. We postulate that this factor may play a role in initiation of myocardial fibrosis in Chagas' disease.     

Effects of chronic exposure to arsenate on the cardiovascular function of rats.

Cardiovascular function was studied in anaesthetised male rats which received 50 micrograms/ml of arsenic (as sodium arsenate) in deionised drinking water for 320 days. High urinary excretion of arsenic was found at the end of treatment and the metal accumulated considerably in the kidneys and liver, which both presented slight alterations. No histopathological modifications were evident in other organs. Base line blood pressure, cardiac inotropism, and chronotropism and cardiovascular reactivity to noradrenaline, acetylcholine, angiotensin II, bradykinin, histamine, and serotonin did not differ in exposed or in control animals. In the exposed group, however, there was potentiation of the effects of vascular beta-adrenoceptor stimulation and a reduction in the vascular responsiveness to angiotensin I. Chronic arsenic exposure did not affect the baroreflex sensitivity but was able to induce sympathetic hyperactivity or hypersensitivity, or both, possibly associated with an antivagal action. Our results might help to explain the cardiovascular alterations seen in people chronically exposed to high concentrations of arsenic.     

Surgery of the crooked nose.

The approach to surgery of the crooked nose has changed significantly in the last two decades due in a large measure to a better understanding of the growth, anatomy, and physiology of the nose. The crooked nose often presents a challenging problem to the surgeon because of the multiplicity of deformities. In most cases, deformities of the external bony and cartilaginous nose, septum and turbinates must all be corrected simultaneously in order to obtain a satisfactory and lasting restoration of the nasal airway as well as of the external nasal configuration.     

A noninvasive, in vivo model for studying strain adaptive bone modeling

We present a noninvasive, in vivo model for strain application in the tibiae of rats. The hind limb of each animal was placed into a device that applied four point bending to the tibia. Bending was applied in the medial-lateral direction causing compression on the lateral surface of the tibia and tension on the anteromedial surface. The peak strain magnitudes were estimated to be between 1600 and 3500 mu strain. In this pilot work, data were collected from 12 rats. The rats received either one cycle per day, four cycles per day, 12 cycles per day, 36 cycles per day, or 108 cycles per day of bending. The experimental (right) tibiae from all of the rats showed new bone formation after 12 days. The control (left) tibiae showed no new bone formation over this period. A better organized, dense bony reaction occurred in regions of lesser strains than in regions of higher strains, where there was a large accumulation of bone easily identified as woven. The organization and density of the newly formed bone appeared to be inversely related to the peak strains in the region. After 40 days of daily loading, the new bone area appeared to be more compact and better mineralized. However, bone formation was still occurring after 40 days. The results of this study suggest that woven bone formation occurred due to the bending stimulus and not due to pathology.     

Effect of intraoperative aprotinin administration on postoperative bleeding in patients undergoing cardiopulmonary bypass operation.

To study the hemostyptic effect of aprotinin (Trasylol) in patients undergoing extracorporeal circulation for coronary artery bypass operations, we randomized 12 of 24 patients to receive aprotinin in high dosage (about 800 mg) during extracorporeal circulation. From the resulting two groups each, one patient was excluded from the study because of postoperative myocardial infarction (control group) and surgical hemorrhage (aprotinin group) leading to a second operation. Although heparin was used for anticoagulation in all 22 patients, all had a marked increase in plasma levels of thrombin-antithrombin III complexes during extracorporeal circulation, indicating an intravasal activation of coagulation. By monitoring the plasma levels of fibrin degradation products in patients without aprotinin therapy, we recorded a concomitant hyperfibrinolysis significantly less pronounced in patients receiving aprotinin (p less than 0.005). The mean total postoperative blood loss was lower in patients receiving aprotinin (620 ml) than in control patients (1000 ml; p less than 0.03). The results confirm previous reports of a hemostyptic effect of aprotinin in cardiac operations. This effect is probably due to a prevention of hyperfibrinolysis.