Tooth avulsion accidents due to urgent and emergency orotracheal intubation.

BACKGROUND: Intubation is necessary during critical situations to reduce the risk of death. In Brazil, a need exists to determine the prevalence of tooth avulsions in emergency and urgent care. The objective of this study was to identify the causes of orotracheal intubation (OTI), the number of tooth avulsions, and the avulsed teeth that result from urgent and emergency intubation. MATERIAL AND METHODS: The sample consisted of 116 patients (total group) in intensive care units (ICUs) distributed across Group 1 (G1), which was composed of 71 patients from an urgent-care hospital, and Group 2 (G2), which was composed of 45 patients from an emergency hospital. Clinical examinations showed dental alveolus with signs of recent exodontia in the upper and lower anterior regions. Sociodemographic data and the reason for intubation were evaluated. The Shapiro-Wilk normality test, chi-square test, Fisher's exact test, Mann-Whitney U test, and univariate logistic regression were performed with a significance level of 5%. RESULTS: The avulsion prevalence was 4.3%, with more cases receiving emergency intubation (n=4). All avulsions occurred in adults, and a significant difference (p=0.011) was observed with regard to the elderly. A 1-year reduction in age increased the chance of tooth avulsion during intubation by 1.09 times; being female increased the chance by 2.88 times. CONCLUSION: Pulmonary problems were the major causes of intubation, with the highest tooth avulsion prevalence observed during emergency intubation. The avulsed teeth were 11, 12, 13, 22, 32, and 33 across all cases.

Action of cytochalasin D on cells of established lines. II. Cortex and microfilaments.

Cells in culture exposed to cytochalasin D (CD) rapidly undergo a long-sustained tonic contraction. Coincident with this contracture the thin microfilaments of the cortex become compacted into feltlike masses. The ravelled filaments of these masses remain actinlike and bind heavy meromyosin; they are not disrupted or disaggregated, but rather, appear to represent a contracted state of the microfilament apparatus of the cell cortex. On continued exposure to CD, 'myoid' bundles, containing thick, dense filaments, and larger fusiform or ribbonlike, putatively myosinoid, aggregates may appear. These appearances are interpreted as consequences of a state of hypercontraction without relaxation induced by CD. They do not occur in CD-treated cells prevented from contracting by inhibitors of energy metabolism, and are readily reversible on withdrawal of CD. Extensive ordered arrays of thin microfilaments develop in cells which are reextending during early recovery.

Action of cytochalasin D on cells of established lines. III. Zeiosis and movements at the cell surface.

The projection of knobby protuberances at the cell surface (zeiosis) is a general cellular response to cytochalasin D (CD), resulting from herniation of endoplasm through undefended places of the cortex during cell contractions and displacement of microfilaments induced by CD. Zeiosis is prevented by agents that interfere with the contractile response to CD, such as inhibitors of energy metabolism or cyclic AMP. The developed protrusions, which remain relatively stable in the presence of CD, contain chiefly mono- or subribosomes, and occasionally other organelles normally resident in endoplasm; compact microfilament felt occupies their bases and extends into their proximal stalks. Protein synthesis in the knobs is less than half of that in the polyribosome-containing endoplasm residual in the main body of the cell. Knobs first protrude singly near the margin of the contracting cells and rapidly cluster into small groups in the periphery even at lower temperature. The clusters then migrate centripetally and coalesce into a large aggregate near the apex of the immobilized and retracted cell: this movement is energy- and temperature-dependent. Aggregation is more prominent and stable in cell lines of epithelial derivation than in fibroblastic or other lines in which nuclear extrusion occurs more readily. The latter is regarded as a special manifestation of zeiosis. Macromarkers, such as latex spherules, migrate like the zeiotic knobs on the cell surfaces in the presence of CD. The aggregated knobs, although persistent for days in the presence of CD, are rapidly recessed after withdrawal of the agent as ruffling is resumed and the cells spread. These movements are discussed in terms of current concepts of mobility of the cell membrane.

Action of cytochalasin D on cells of established lines. I. Early events.

HeLa, Vero, L, HEp2, and MDBK cells respond immediately to 0.2-0.5 microg/ml cytochalasin D (CD) with sustained contraction (contracture), loss of microvilli, expression of endoplasmic contents (zeiosis), nuclear protrusion, and extension of cytoplasmic processes. The development of these changes is depicted, and the dose-response patterns in these cell lines are described. MDBK is generally most resistant and HeLa most sensitive to these effects of CD. Cells in G(1) are most sensitive to CD; responsiveness decreases progressively during early S and is least in mid S through G(2). CD inhibits transport of [(14)C]deoxyglucose in HeLa by about 45% but has no significant effect on hexose uptake in Vero and MDBK; sugar transport is thus apparently unrelated to any morphologic effect of CD. Although spreading and attachment are impeded, CD does not decrease and may even enhance the adhesiveness of established monolayers. Contraction appears to be a primary early effect of CD, upon which other visible changes follow. It is prevented by some inhibitors of energy metabolism (deoxyglucose and dinitrophenol) and does not occur in glycerinated models without ATP. The possible bases of the contractile response to CD are discussed. Although direct or indirect action of CD on some microfilaments may occur, a generalized structural disruption of contractile filaments by CD is considered unlikely.

Human muscle phosphoglycerate mutase deficiency: newly discovered metabolic myopathy.

Muscle phosphoglycerate mutase activity was decreased (5.7 percent of the lowest control value) in a 52-year-old man with intolerance for strenuous exercise and recurrent pigmenturia since adolescence. All of the other enzymes of glycolysis had normal activities, and glycogen concentration was normal. Electrophoretic, heat lability, and mercury inhibition studies showed that the small residual activity in the patient's muscle was represented by the brain (BB) isoenzyme of phosphoglycerate mutase, suggesting a genetic defect of the M subunit which predominates in normal muscle. The prevalence of the BB isoenzyme in other tissues, including muscle culture, may explain why symptoms were confined to muscle.

Myoblast fusion and innervation with rat motor nerve alter distribution of acetylcholinesterase and its mRNA in cultures of human muscle.

To elucidate the mechanisms underlying acetylcholinesterase (AChE) localization, we analyzed the distribution of AChE and Ache mRNA during myogenesis in cocultures of human muscle and fetal rat spinal cord. We observed a temporal coincidence in alterations of AChE localization and nuclei expressing the message, suggesting developmental regulation at the mRNA level. Nonuniform mRNA staining among nuclei suggests asynchronous regulation, also supporting an earlier proposal that transcription proceeds intermittently. Asynchrony seems to be overridden by generally acting factors during myoblast fusion, when message is up-regulated, and at the onset of muscle contractions, when it becomes restricted to some nuclei in the junctional region and focal patches of AChE appear near nerve contacts. Coincidence of mRNA down-regulation and synthesis of stable basal lamina-bound AChE suggests coordinated adaptation, so that sufficient enzyme may be derived from low message levels.

Muscle phosphofructokinase deficiency. Biochemical and immunological studies of phosphofructokinase isozymes in muscle culture.

Muscle cultures from three unrelated patients with muscle phosphofructokinase (PFK; EC 2.7.1.11) deficiency (Glycogenosis type VII; Tarui disease) had normal PFK activity and normal morphology. Chromatographic and immunological studies showed that normal muscle cultures express all three PFK subunits, M (muscle-type), L (liver-type), and P (platelet-type) and contain multiple homotetrameric and heterotetrameric isozymes. Muscle cultures from patients lack catalytically active M subunit-containing isozymes, but this is compensated for by the presence of P- and L-containing isozymes. Despite the lack of muscle-type PFK activity, presence of immunoreactive M subunit was demonstrable by indirect immunofluorescence, suggesting a mutation of the structural gene coding for the M-subunit of PFK.

Heterogeneity of the molecular lesions in inherited phosphofructokinase deficiency.

Human phosphofructokinase (PFK; EC 2.7.1.11) exists in tetrameric isozymic forms. Muscle and liver contain the homotetramers M4 and L4, whereas erythrocytes contain five isozymes composed of M (muscle) and L (liver) subunits, i.e., M4, M3L, M2L2, ML3, and L4. Inherited defects of erythrocyte PFK are usually partial and are described in association with heterogeneous clinical syndromes. To define the molecular basis and pathogenesis of this enzymopathy, we investigated four unrelated individuals manifesting myopathy and hemolysis (glycogenosis type VII), isolated hemolysis, or no symptoms at all. The three symptomatic patients showed high-normal hemoglobin levels, despite hemolysis and early-onset hyperuricemia. They showed total lack of muscle-type PFK and suffered from exertional myopathy of varying severity. In the erythrocytes, a metabolic crossover was evident at the PFK step: the levels of hexose monophosphates were elevated and those of 2,3-diphosphoglycerate (2,3-DPG) were depressed, causing strikingly increased hemoglobin-oxygen affinity. In all cases, the residual erythrocyte PFK consisted exclusively of L4 isozyme, indicating homozygosity for the deficiency of the catalytically active M subunit. However, presence of immunoreactive M subunit was shown in cultured fibroblasts by indirect immunofluorescence with monoclonal anti-M antibody. The fourth individual was completely asymptomatic, had normal erythrocyte metabolism, and had no evidence of hemolysis. His residual erythrocyte PFK showed a striking decrease of the L4, ML3, and M2L2 isozymes, secondary to a mutant unstable L subunit. Identical alterations of erythrocyte PFK were found in his asymptomatic son, indicating heterozygosity for the mutant unstable L subunit in this kindred. These studies show that, except for the varying severity of the myopathic symptoms, glycogenosis type VII has highly uniform clinical and biochemical features and results from homozygosity for mutant inactive M subunit(s). The absence of anemia despite hemolysis may be explained by the low 2,3-DPG levels. The hyperuricemia may result from hyperactivity of the hexose monophosphate shunt. In contrast, the clinically silent carrier state results from heterozygosity for mutant M or L subunit. Of the two, the M subunit appears to be more critical for adequate glycolytic flux in the erythrocyte, since its absence is correlated with hemolysis.

Effects of teleocidin and the phorbol ester tumor promoters on cell transformation, differentiation, and phospholipid metabolism.

The potent tumor-promoting agent 12-O-tetradecanoylphorbol-13-acetate (TPA) and related diterpene phorbol esters have been shown to enhance viral transformation and anchorage-independent growth, inhibit differentiation, and stimulate phosphatidylcholine turnover in various cell culture systems. In the present study, we report that teleocidin, and indole alkaloid isolated from Streptomyces, induces several biological effects similar to those of TPA in cell culture. Both TPA and teleocidin enhanced transformation of a clone of Fischer rat embryo cells (CREF) by a temperature-sensitive mutant of adenovirus type 5 (H5ts125); enhanced the cloning efficiency in agar of E11 cells, a clone of H5ts125-transformed Sprague-Dawley rat embryo cells; inhibited melanogenesis in murine B-16 melanoma cells; inhibited myogenesis in myoblast cultures established from normal human skeletal muscle; and stimulated choline release from prelabeled phospholipids of C3H10T 1/2 mouse cells. In general, TPA and teleocidin were equipotent in inducing these biological effects and were most active in the 3- to 10-ng/ml range, i.e., approximately 10(-8) to 10(-9) M. These studies provide further evidence that teleocidin represents a new class of tumor-promoting agents with properties similar to, if not identical with, those of the phorbol ester tumor promoters. These findings also suggest that cell culture systems can be used to identify new types of tumor-promoting agents in addition to the diterpene phorbol esters.

Isolation of a cDNA clone encoding subunit IV of human cytochrome c oxidase.

We have isolated a full-length human liver cDNA clone specifying the nuclear-encoded subunit IV of the human mitochondrial respiratory chain enzyme, cytochrome c oxidase (COX; EC 1.9.3.1). The human cDNA clone is highly homologous to its bovine counterpart in the coding regions for both the mature polypeptide and the presequence, and the gene is evolving more slowly than that of any of the three mitochondrially encoded COX subunit genes. We find no preliminary evidence for tissue-specific isoforms of COX subunit IV, as Northern analysis of muscle, liver, and HeLa cell RNA shows an identically sized transcript in each cell type.

Differentiation of glial cells and motor neurons during the formation of neuromuscular junctions in cocultures of rat spinal cord explant and human muscle.

Motor axons extending from embryonic rat spinal cord explants form fully mature neuromuscular junctions with cocultured human muscle. This degree of maturation is not observed in muscle innervated by dissociated motor neurons. Glial cells present in the spinal cord explants seem to be, besides remaining interneurons, the major difference between the two culture systems. In light of this observation and the well documented role of glia in neuronal development, it can be hypothesized that differentiated and long-lived neuromuscular junctions form in vitro only if their formation is accompanied by codifferentiation of neuronal and glial cells and if this codifferentiation follows the spatial and temporal pattern observed in vivo. Investigation of this hypothesis necessitates the characterization of neuronal and glial cell development in spinal cord explant-muscle cocultures. No such study has been reported, although these cocultures have been used in numerous studies of neuromuscular junction formation. The aim of this work was therefore to investigate the temporal relationship between neuromuscular junction formation and the differentiation of neuronal and glial cells during the first 3 weeks of coculture, when formation and development of the neuromuscular junction occurs in vitro. The expression of stage-specific markers of neuronal and glial differentiation in these cocultures was characterized by immunocytochemical and biochemical analyses. Differentiation of astrocytes, Schwann cells, and oligodendrocytes proceeded in concert with the differentiation of motor neurons and neuromuscular junction formation. The temporal coincidence between maturation of the neuromuscular junction and lineage progression of neurons and glial cells was similar to that observed in vivo. These findings support the hypothesis that glial cells are a major contributor to maturity of the neuromuscular junction formed in vitro in spinal cord explant-muscle cocultures.

Immunocytochemical analysis of normal and acid maltase-deficient muscle cultures.

Muscle cultures from patients with infantile and later-onset acid maltase deficiency (AMD) and from unaffected controls were studied immunocytochemically with anti-acid maltase (anti-AM) antibodies and fluorescein-labeled goat anti-rabbit IgG second antibody. In control muscle cells, an intense granular distribution of staining was seen, consistent with lysosomal localization of AM. Cultured muscle cells from two patients with infantile AMD (Pompe's disease) did not fluoresce, whereas cells from two patients with AMD of later onset did fluoresce, showing a distribution similar to that of controls.

Phosphorylase isoenzymes in normal and myophosphorylase-deficient human heart.

Phosphorylase isoenzymes were studied by acrylamide-slab electrophoresis in normal tissues and in the heart of a child with a fatal infantile form of myophosphorylase deficiency. Of the three bands present in normal human heart, two were missing in the patient's heart: the slow "muscle" isoenzyme and the intermediate band. Only the fast "cardiac" isoenzyme remained. When extracts of normal skeletal muscle and the patient's heart were mixed in appropriate conditions, the intermediate band reappeared in the electropherogram. Phosphorylase activity in extracts of the patient's heart was not inhibited by antibodies against purified enzyme from mature human muscle, whereas normal human heart phosphorylase was inhibited by approximately 50%. These results suggest that the intermediate band of human heart phosphorylase is a hybrid of skeletal and cardiac muscle isoenzymes. Retained activity of the cardiac isoenzyme may explain why patients genetically lacking skeletal muscle phosphorylase do not have clinical heart disease.

Cytochrome c oxidase deficiency in Leigh's syndrome: genetic evidence for a nuclear DNA-encoded mutation.

Although an apparently generalized defect of cytochrome c oxidase (COX) occurs in many patients with subacute necrotizing encephalomyelopathy (Leigh's syndrome), the mode of inheritance in this disorder is not known. We transformed COX-deficient fibroblasts from a child with Leigh's syndrome with simian virus 40 to obtain cells with an infinite life span. These cells were still COX-deficient, grew normally in HAT medium, and were ouabain-sensitive. We fused these cells with a HAT-sensitive, ouabain-resistant variant of HeLa cells (HeLacot) and isolated surviving hybrid clones in ouabain-containing HAT medium. Prolonged cultivation of the hybrids was accompanied by preferential loss of HeLacot mitochondrial DNA (mtDNA), as determined by mtDNA restriction patterns of parental and hybrid cell DNA with the restriction endonuclease HaeII. COX activity was normal or higher than normal in hybrids, including the progeny of cell clones that had lost almost all the HeLacot mtDNA. These data demonstrate that COX deficiency in this Leigh's syndrome patient's cells was corrected by a nuclear DNA-encoded factor from the HeLacot parent and ruled out an mtDNA mutation as the basis for COX deficiency. This system can be used to determine whether different generalized mitochondrial disorders are due to mutations of nuclear or mtDNA.

Juvenile-onset acid maltase deficiency with unusual familial features.

From early childhood, two brothers had mild gait difficulties due to acid maltase deficiency (AMD). Biochemical studies of family members were consistent with autosomal recessive inheritance, but the asymptomatic mother had AM activity in the homozygote range, and her parents had decreased AM activity. The asymptomatic mother may be homozygous for the adult-onset variant of AMD. Alternatively, either the mother or the children may be genetic compounds of the childhood and adult forms of AMD.

Muscle phosphoglycerate mutase (PGAM) deficiency: a second case.

Muscle phosphoglycerate mutase (PGAM) activity was markedly decreased (6% of the normal mean) in a 17-year-old girl with recurrent myoglobinuria after intense exercise. Muscle biopsy showed increased PAS stain; glycogen concentration was twice normal. Studies of anaerobic glycolysis in vitro showed decreased lactate production with glycogen, and with all hexose phosphate glycolytic intermediates, which was corrected by addition of purified PGAM to the reaction mixtures. A defect of the M subunit of PGAM was documented by electrophoretic, heat lability, and mercury inhibition studies. Intermediate PGAM activities (39 and 50% of normal) were found in muscle biopsies from the patient's asymptomatic parents. These data confirm the clinical, morphologic, and biochemical features described in the first patient with PGAM deficiency and suggest autosomal-recessive transmission of the trait.

Muscle phosphoglycerate mutase deficiency.

A 52-year-old man complained since adolescence of cramps and pigmenturia after 15 to 30 minutes of intense exercise. There was no family history of neuromuscular diseases, and strength was normal. The rise of venous lactate after forearm ischemic exercise was abnormally low. Histochemical and ultrastructural studies of a muscle biopsy showed mild increase of glycogen, which was confirmed by biochemical analysis. Studies of anaerobic glycolysis in vitro showed decrease lactate formation with glycogen and with all hexosephosphate glycolytic intermediates, suggesting a defect below the phosphofructokinase reaction. Muscle phosphoglycerate mutase (PGAM) activity was 5.7% of the lowest control, while all other enzymes of glycolysis had normal activities. Electrophoretic, heat lability, and mercury inhibition studies showed that the small residual activity of PGAM in the patient's muscle was represented by the brain (BB) isoenzyme, suggesting a genetic defect of the M subunit that predominates in normal muscle. The prevalence of the BB isoenzyme in other tissues, including muscle culture, may explain why symptoms were confined to muscle.

Differential diagnosis of fatal and benign cytochrome c oxidase-deficient myopathies of infancy: an immunohistochemical approach.

To differentiate the 2 major myopathies of infancy due to cytochrome c oxidase (COX) deficiency, we studied muscle biopsies from 4 patients with fatal myopathy and 4 with benign myopathy using biochemical, histochemical, and immunohistochemical techniques. Immunohistochemistry with antibodies directed against individual subunits of COX differentiated the 2 phenotypes: the fatal infantile myopathy was characterized by absence of the nuclear DNA (nDNA)-encoded subunit VIIa,b of COX, while in the benign myopathy both VIIa,b and the mitochondrial DNA (mtDNA)-encoded subunit II were absent. Early differential diagnosis between fatal and benign COX-deficient myopathies is of critical importance for prognosis and management of these infants, because the benign form is initially life-threatening but ultimately reversible.

Multiple mtDNA deletions features in autosomal dominant and recessive diseases suggest distinct pathogeneses.

Multiple mitochondrial DNA (mtDNA) deletions have been described in patients with autosomal dominant progressive external ophthalmoplegia (AD-PEO) and in autosomal recessive disorders including mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) and autosomal recessive cardiomyopathy ophthalmoplegia (ARCO). The pathogenic bases of these disorders are unknown. We studied three patients with AD-PEO and three patients with autosomal recessive (AR)-PEO (two patients with MNGIE and one patient with ARCO). Histochemistry and Southern blot analyses of DNA were performed in skeletal muscle from the patients. Muscle mtDNA was used to characterize the pattern and amounts of the multiple mtDNA rearrangements; PCR analysis was performed to obtain finer maps of the deleted regions in both conditions. The patients with AD-PEO had myopathic features; the patients with AR-PEO had multisystem disorders. The percentage of ragged-red and cytochrome c oxidase-negative fibers tended to be higher in muscle from the patients with AD-PEO (19% +/- 13.9, 29.7 +/- 26.3) than in muscle from the patients with AR-PEO (1.4% +/- 1.4, 3.3% +/- 3.2; p < 0.10). The sizes of the multiple mtDNA deletions ranged from approximately 4.0 to 10.0 kilobases in muscle from both groups of patients, and in both groups, we identified only deleted and no duplicated mtDNA molecules. Patients with AD-PEO harbored a greater proportion of deleted mtDNA species in muscle (31% +/- 5.3) than did patients with AR-PEO (9.7% +/- 9.1; p < 0.05). In the patients with AD-PEO, we identified a deletion that included the mtDNA heavy strand promoter (HSP) region, which had been previously described as the HSP deletion. The HSP deletion was not present in the patients with AR-PEO. Our findings show the clinical, histologic, and molecular genetic heterogeneity of these complex disorders. In particular, the proportions of multiple mtDNA deletions were higher in muscle samples from patients with AD-PEO than in those from patients with AR-PEO.

Widespread tissue distribution of mitochondrial DNA deletions in Kearns-Sayre syndrome.

We performed Southern analysis of mitochondrial DNA (mtDNA) in 6 tissues from a patient with Kearns-Sayre syndrome and found a single deletion of 4.9 kb in all tissues. The percentage of deleted mtDNAs varied widely between tissues, from only 4% in smooth muscle to approximately 50% in skeletal muscle. Samples of DNA obtained from 3 different skeletal muscles and from separate areas of individual tissues showed little variation in percentage of deleted mtDNA. Biochemical analysis showed no clear correlation between mitochondrial enzyme activity and deleted mtDNAs.