[Craniofacial malformations in prenatal ultrasound evaluation. Literature review]. / Malformacje twarzoczaszki w prenatalnej ocenie ultrasonograficznej. Przeglad pismiennictwa.

Fetal face is the key anatomical location, both psychologically and clinically for the mother and the clinician. Ultrasound prenatal examination of the maxillofacial region allows to evaluate the fetal face in the first weeks of gestation. In ambulatory intravaginal ultrasound, sensitivity of the facial defect detection is 20-30% in cases without the risk of TORCH and fetal abnormalities, which may arouse suspicion of the presence of facial malformation. Facial defects form a wide group of pathologies. Unfortunately challenges connected with 2D and 3D ultrasound imaging cause frequent misdiagnoses in early gestation. Maxillofacial abnormalities can be solitary or they can coexist with other abnormalities or syndromes. In case of detecting a facial defect, a precise and thorough ultrasound of whole fetal body is necessary whereas in case of detecting any fetal body abnormality a precise and thorough ultrasound examination of the fetal face is obligatory Unfortunately most contemporary prenatal ultrasound standards propose only the overall "face and orbits" evaluation of the fetal face. The evaluation is difficult at 23 and 24 weeks of gestation and seems to be rather challenging in the third trimester of gestation. Not only facial malformations but also facial dimorphic features may lead to the suspicion of genetic syndrome and they may be extremely important in making correct diagnosis. Attempts at standardization in fetal face ultrasound evaluation have proved to be extremely difficult. Advantages of 2D ultrasound over 3D ultrasound and 3D ultrasound over 2D ultrasound in fetal face evaluation have been a topic of much debate. Most typically fetal face is examined with 2D ultrasound in a few basic planes: coronary sagittal, frontal and oblique. The planes preferred in the evaluation of facial structures are discussed in details in the paper Fetal facial defects evaluated in the ultrasound examination may be divided into a few main groups: examination of the orbit and eyeball defects, examination of the external nose and nasal cavity defects, examination of the cleft defects involving the lip, hard and soft palate which may be unilateral or bilateral, examination of external ear defects, examination of mandibular defects and detection of fetal tumors. 3D ultrasound evaluation of the fetal face is extremely useful in visualization of the face, thus presenting a problem to parents and clinicians. Prenatal ultrasound examination provides necessary and extremely useful data concerning fetal facial abnormalities, which allows to plan care and further treatment including interventions in pediatric ENT, pediatric surgery and plastic surgery areas. Cooperation of ultrasound diagnostician and clinicians taking care of a child in the future is therefore necessary when designing treatment scheme in cases of fetal facial defects.

Fetal face: the whole picture.

The fetal face is an essential source of information. Its evaluation makes it possible to diagnose several fetal diseases and syndromes. Three-dimensional ultrasound and four-dimensional ultrasound facilitate the evaluation of superficial anatomical facial structures and have become essential complementary tools to two-dimensional ultrasound, providing additional and more precise information about the presence and severity of facial defects. This article reviews the normal facial development essential to understand the pathogenesis of facial malformations as well as the assessment of a normal and dysmorphic face with two-dimensional, three-dimensional and four-dimensional ultrasound and discusses the clinical implications of detecting facial anomalies in the prenatal period.

Muscle-specific loss of apoptosis-inducing factor leads to mitochondrial dysfunction, skeletal muscle atrophy, and dilated cardiomyopathy.

Cardiac and skeletal muscle critically depend on mitochondrial energy metabolism for their normal function. Recently, we showed that apoptosis-inducing factor (AIF), a mitochondrial protein implicated in programmed cell death, plays a role in mitochondrial respiration. However, the in vivo consequences of AIF-regulated mitochondrial respiration resulting from a loss-of-function mutation in Aif are not known. Here, we report tissue-specific deletion of Aif in the mouse. Mice in which Aif has been inactivated specifically in cardiac and skeletal muscle exhibit impaired activity and protein expression of respiratory chain complex I. Mutant animals develop severe dilated cardiomyopathy, heart failure, and skeletal muscle atrophy accompanied by lactic acidemia consistent with defects in the mitochondrial respiratory chain. Isolated hearts from mutant animals exhibit poor contractile performance in response to a respiratory chain-dependent energy substrate, but not in response to glucose, supporting the notion that impaired heart function in mutant animals results from defective mitochondrial energy metabolism. These data provide genetic proof that the previously defined cell death promoter AIF has a second essential function in mitochondrial respiration and aerobic energy metabolism required for normal heart function and skeletal muscle homeostasis.

Muscular pseudohypertrophy (steatosis) in a bovine fetus.

Muscular pseudohypertrophy was diagnosed in the cervical musculature of a full-term crossbred Simmental fetus delivered by fetotomy. Only head and cervical regions were submitted for pathologic examination; the rest of the fetal body was reportedly normal. The neck musculature of the fetus was markedly deformed by 23 cm and 18 cm in diameter, firm, spherical masses that consisted of enlarged and pale left splenius and right serratus ventralis cervicis muscle, respectively, covered by intact skin. Additionally, lipomatous masses were present within the cervical vertebral canal, compressing the spinal cord. Microscopically, the prominent muscular enlargement was due to massive adipose and fibrous connective tissue replacement of atrophic muscle. Focal myelodysplasia and astrocytosis affecting the grey matter was detected in the mid-cervical region of the spinal cord, accompanied by degeneration in the ascending and descending tracts of the remaining cord segments. Abnormal spinal cord development as a result of severe spinal cord compression by the lipomatous masses within the spinal canal leading to replacement of muscle by fat and fibrous tissue was considered to be the cause of the muscular malformation in this fetus.

Embryonic deregulation of muscle stress signaling pathways leads to altered postnatal stem cell behavior and a failure in postnatal muscle growth.

PW1 is a mediator of p53 and TNFalpha signaling pathways previously identified in a screen to isolate muscle stem cell regulators. We generated transgenic mice carrying a C-terminal deleted form of PW1 (DeltaPW1) which blocks p53-mediated cell death and TNFalpha-mediated NFkappaB activation fused to the myogenin promoter. Embryonic/fetal muscle development appears normal during transgene expression, however, postnatal transgenic pups display severe phenotypes including runtism, reduced muscle mass and fiber diameters resembling atrophy. Atrogin-1, a marker of skeletal muscle atrophy, is expressed postnatally in transgenic mice. Electron microscopic analyses of transgenic muscle reveal a marked decrease in quiescent muscle satellite cells suggesting a deregulation of postnatal stem cells. Furthermore, transgenic primary myoblasts show a resistance to the effects of TNFalpha upon differentiation. Taken together, our data support a role for PW1 and related stress pathways in mediating skeletal muscle stem cell behavior which in turn is critical for postnatal muscle growth and homeostasis. In addition, these data reveal that postnatal stem cell behavior is likely specified during early muscle development.

Is Kugelberg-Welander spinal muscular atrophy a fetal defect?

Twelve children who had developed Kugelberg-Welander (K-W) spinal muscular atrophy (SMA) before the age of six years were investigated. Electrophysiological, histochemical, ultrastructural, and biochemical studies demonstrated features of immature muscle fibers suggesting a fetal defect as in the Werdnig-Hoffmann (W-H) form of SMA. Comparison with known patterns of human myogenesis and of experimental denervation of immature muscle suggested that the defect in K-W SMA probably takes place in fetal life at a stage later than in W-H SMA. In contrast to W-H SMA, a considerable percentage of mature fibers of normal structure and diameter were present. The immature fibers impair the normal development of muscle cells by preventing the increase in number of mature fibers and causing an overloading of the normal fibers with consequent hypertrophy and eventually destructive changes. This is the pattern in K-W disease that distinguishes the juvenile form of SMA from W-H disease.

Werdnig-Hoffmann disease. The effects of intrauterine onset on lung growth.

Thoracic gas volume (TGV), resting lung volume at end expiration, was measured by the plethysmographic technique in 9 infants with Werdnig-Hoffmann disease. Five of these infants were considered to have intrauterine onset of the disease; the mother in each case had reported a pronounced reduction in fetal activity during the last trimester of pregnancy, and 4 were found to be hypotonic at birth. The remaining 4 infants appeared normal at birth and did not develop any signs of the disease until between 2 and 12 weeks postnatally. Those with intrauterine onset of disease had a significantly reduced TGV (mean 20.8 ml kg(-1)), whereas those with postnatal onset had normal lung volumes (means 36.1 ml kg(-1)). The reduction in lung volume correlated only with intrauterine onset of disease, and was not related to either the degree of muscle weakness or the duration of disease. There is increasing evidence that fetal breathing movements may be one of the essential prerequisites for normal fetal lung development. It is therefore possible that diminished fetal breathing movements, resulting from weakness of the respiratory musculature in utero, could be responsible for the reduction in lung volume found in those infants with intrauterine onset of the disease.

Formation of primary and secondary myotubes in aneural muscles in the mouse mutant peroneal muscular atrophy.

The role of motor innervation in supporting and regulating muscle development was studied using aneural muscles in the hindlimb of the mouse mutant peroneal muscular atrophy (pma). This is a single-locus autosomal mutation where homozygous animals lack the common peroneal nerve, so that muscles in the anterolateral compartment of the lower leg develop entirely without innervation. In adults, these muscles are extremely atrophied, and the mice display a clubfoot deformity. The mutant animals provide a preparation in which aspects of muscle formation can be studied in muscles that have never been exposed to direct contact with somatic motor or sensory axons, without pharmacological or surgical intervention. Using quantitative electron microscopy, we found that normal numbers of primary myotubes formed in aneural pma EDL muscles, but a greater than normal proportion degenerated during the first 2 days after their formation. Secondary myotubes appeared at their normal time and position within the muscle, initially in normal numbers, so that the ratio of secondary to primary myotubes initially was greater in pma than in CF1 control strain mice. No abnormalities in ultrastructure were seen until the time of birth, when retardation in development was obvious, together with invading macrophages and degenerating myofibres. The results show that secondary myotube formation in the mouse, as in the chick (B. J. Fredette and L. T. Landmesser, Dev. Biol. 143, 19-35, 1991) is not directly dependent on innervation. In control muscles, secondary myotubes first form in the vicinity of endplates on primary myotubes. No aggregations of ACh receptors or acetylcholinesterase were present in the aneural muscles, showing that these are neurally induced in the mouse, but secondary myotubes formed in their normal position indicating that positional information related to endplate formation is present in aneural muscles.

Regulation of myogenesis in paralyzed muscles in the mouse mutants peroneal muscular atrophy and muscular dysgenesis.

The roles of innervation, muscle electrical activity, and muscle contraction in regulating the formation and survival of primary and secondary myotubes during embryonic and fetal development of skeletal muscle were studied using the mouse mutants peroneal muscular atrophy (pma) and muscular dysgenesis (mdg). The pma phenotype includes the absence of the peroneal division of the sciatic nerve, so muscles in the anterior compartment of the lower hindlimb are aneural throughout development. Muscles in mdg mice are paralyzed due to the absence of excitation-contraction coupling and hyperinnervated due to suppression of motoneuron death in consequence of their paralysis, but otherwise are electrically excitable and receive synaptic transmission. In a quantitative comparison between control and mutant extensor digitorum longus (EDL) muscles at E15, primary myotube numbers were depressed by 20-30% in both mutants and in paralyzed or denervated muscles from control strain animals. The number of secondary myotubes, however, was normal in pma mutants and two and a half times greater than normal in the hyperinnervated mdg EDL muscles, so that the ratio of secondary to primary myotubes was increased by 300% in the mutant with respect to heterozygous or -/- littermates. Chronic paralysis with tetrodotoxin (TTX) caused no further depression of primary myotube numbers in aneural pma muscles, but secondary myotube numbers were reduced by 40%, reducing the ratio of secondary to primary myotubes by 35%. We conclude that during normal development the generation of secondary myotubes depends on neurally evoked electrical activity in primary myotubes, which stimulates mitosis of secondary myoblasts. The effect of TTX shows that aneural pma primary myotubes discharge spontaneous myogenic action potentials, while mdg muscles may receive greater than normal electrical activation due to their hyperinnervation, explaining the presence and numbers of secondary myotubes in the mutant mouse muscles.

Morphological differences between the atrophied small muscle fibres in amyotrophic lateral sclerosis and Werdnig-Hoffmann disease.

Muscle biopsies from 5 cases of Werdnig-Hoffmann disease and 4 cases of ALS were investigated by histology and electronmicroscopy. The differences in morphology found in the atrophic muscle fibers in ALS and in W.H. disease consisted mainly in the shape and structure of their cells and the number of the nuclei. Atrophic muscle fibres irregular in shape and size with degenerative changes and accumulated nuclei observed in ALS were markedly different from the picture of the fibres in W.H. disease. The presence of small muscle cells uniform diameter with well preserved architecture and numerous myotube-like cells seem to indicate a foetal defect in children with W.H. disease.

Síndrome oculofaringeo: informe de un paciente / Oculopharyngeal syndrome: report of one case

El síndrome oculofaríngeo (Distrofia Muscular oculofaríngea) es una enfermedad transmitida genéticamente con carácter autosómico dominante, caracterizada por la presencia de ptosis palpebral bilateral con disfagia progresiva que se presenta en etapas tardias de la vida; sido observada también se ha informado en familias de distintos grupos étnicos. El origen de la enfermedad no es completamente conocido, algunas evidencias sugieren que el problema es primariamente miopático; su identificación se bas en la forma de presentación del cuadro clínico, las alteraciones motoras inespecíficas de la región faringoesofágica y los hallazgos histopatológicos en músculo esquelético estriado; el tratamiento más satisfactorio de este tipo de disfagia, es la miotomía cricofaríngea. Se informa de un caso estudiado en el Depto. Cirurgía General del H.G. CM "La Raza", I.M.S.S. Masculino de 61 años, con antecedente del síndrome en su padre, su padecimiento de 4 años de evolución con ptosis palpebral bilateral, disfagia progresiva y últimamente disfonía; la evolución clínica, los resultados de laboratorio (TGO-DHL-IGA-IgG), los estudios de gabinete (esófago fluoroscopía, laringoscopía indrecta, esofagoscopía, manometría esofágica, electromiografía) y los hallazgos histopatológicos e inmunocitoquímicos de músculo estriado, confirmaron la presencia del síndrome; fue sometido a miotomia cricofaríngea de 5.0 cm. de longitud, evolucionó satisfactoriamente por alivio de la disfagia y mejoria nutricional. Es important