Cranial Fontanel Research Articles

Microcambeva ribeirae sp. n. (Teleostei: Siluriformes: Trichomycteridae): a new sarcoglanidine catfish from the Rio Ribeira do Iguape basin, southeastern Brazil

A second species of Microcambeva, M. ribeirae, is described from the Rio Ribeira do Iguape basin, S o Paulo, southeastern Brazil, which constitutes the southernmost record for sarcoglanidine catfishes. It is distinguished from M. barbata by a series of morphological features, including nasal barbel extent, position of the eye, first pectoral-fin ray extent, position of the anal fin, position of the posterior pore of the supraorbital canal, frontal shape, cranial fontanel extent, lateral process of the sphenotic, absence of the anterior ossification of palatine, and size of the posterior process of the palatine and supraorbital bone.

Trichomycterus maracaya, a new catfish from the upper rio Paraná, southeastern Brazil (Siluriformes: Trichomycteridae), with notes on the T. brasiliensis species-complex

Trichomycterus maracaya, a new species of Trichomycteridae, is described from a streamlet in the upper rio Paraná, Poços de Caldas, State of Minas Gerais, southeastern Brazil. The following putative autapomorphies distinguishes T. maracaya from congeneric species: 1) row of lateral blotches not forming a stripe at any phase during ontogeny; 2) superficial layer of pigmentation of juveniles and large (presumably adults) specimens consisting solely of scattered chromatophores. Furthermore, the new species is characterized by a combination of yellow ground color in life and mottled pattern formed by small to medium-sized, brown, irregularly-coalescent, well-defined deeper-lying blotches, and more superficial dots on the body. Trichomycterus maracaya is assigned to the T. brasiliensis species-complex (which includes T. brasiliensis, T. iheringi, T. mimonha, T. potschi, T. vermiculatus, and several undescribed species apparently endemic to the main river basins draining the Brazilian Shield) based on the presence of: 1) blotches in four longitudinal rows of deeper-lying pigmentation on the trunk large, horizontally-elongated, and well-defined; 2) pectoral fin with I+5-6 rays; 3) separation between the anterior and posterior cranial fontanels by the primordial epiphyseal cartilaginous bar being present only in larger specimens; and 4) pelvic-fin bases very close to each other, sometimes in contact.

The late Miocene Phractocephalus catfish (Siluriformes: Pimelodidae) from Urumaco, Venezuela: additional specimens and reinterpretation as a distinct species

Based on additional specimens the fossil pimelodid catfish from the upper Miocene Urumaco Formation, Falcón State, Venezuela originally assigned to the extant species Phractocephalus hemioliopterus is described as a new, extinct species. †Phractocephalus nassi n. sp. is diagnosed by the following combination of characters: 1) posterior half of frontals and anterior half of supraoccipital with elongate, coarse ridges and sulci in addition to reticulating ridges and subcircular pits; 2) very broad and ornamented mesethmoid bone; 3) lateral ethmoid margin convex and eliminating orbital notch but not projecting far anteriorly over palatine condyle; 4) anterior cranial fontanelle closed or represented by a small pit; 5) supraoccipital process rounded laterally and posterolaterally, concave posteriorly and completely concealing Weberian complex in dorsal view; 6) opercle covered with reticulating ridges and pits; 7) cleithrum coarsely ornamented along ventral edge and bulging outward lateral to spine articulation; 8) pectoral spine mostly ornamented with coarse ridges and sulci. †Phractocephalus nassi is compared to modern P. hemioliopterus and an undescribed extinct species from the upper Miocene Solimões Formation, Acre, Brazil. New diagnostic characters of Phractocephalus are presented that apply to the modern and fossil species, including: 1) ornamentation of skull, pectoral girdle and fin spines comprising a coarse meshwork of reticulating ridges surrounding rounded pits plus some elongate ridges and sulci; 2) supraoccipital posterior process greatly expanded laterally and posteriorly behind occipital wall; 3) lateral ethmoid and sphenotic broadly sutured behind eye; 4) anterior cranial fontanelle reduced or completely closed and posterior cranial fontanelle closed; 5) vomerine tooth plate large, roughly pentagonal to triangular in form, and with fine teeth. Today Phractocephalus ranges widely throughout the lowland Orinoco, Amazon and Essequibo basins. However, the genus does not occur west or north of the Andes or Venezuelan coastal ranges. Recognizing the Urumaco Phractocephalus as a distinct species does not alter the obvious conclusion that this catfish marks a large river connection between the Caribbean coastal region and the Orinoco system during at least part of the Neogene. Other Urumaco fossils show this same biogeographic relationship.

Nucleated red blood cell count at birth as an index of perinatal brain damage

Objective: The prognostic value of the nucleated red blood cell count at birth with respect to perinatal brain damage and neonatal outcome was assessed in infants at high risk of having neurologic damage. Study Design: The nucleated red blood cell count at birth, pulsed Doppler ultrasonography in the cerebral arteries, cranial fontanelle sonograms, and neurodevelopmental status were evaluated in 337 newborn infants. Results: The nucleated red blood cell count at birth was significantly higher (1) in neonates with abnormal Doppler ultrasonographic parameters for the cerebral arteries at 48 to 72 hours after birth than in healthy neonates, (2) in 6-month-old infants with sequelae of hypoxic-ischemic encephalopathy than in healthy infants, and (3) in 3-year-old children with abnormal developmental status than in those with no abnormalities at follow-up. Significant correlations were observed between the nucleated red blood cell count and gestational age, Apgar score at 1 and 5 minutes, pH, base deficit, fraction of inspired oxygen, blood oxygen content, and birth weight. Conclusions: The nucleated red blood cell count at birth not only reflects a response of the infant to perinatal hypoxia but is also a reliable index of perinatal brain damage. (Am J Obstet Gynecol 1999;181:1500-5.)

Relationship between neonatal nucleated red blood cell counts and hypoxic-ischemic injury

To determine if nucleated red blood cell counts(RBC) are different in infants who develop intraventricular hemorrhage and periventricular leukomalacia in the first week of life and in those who do not. Nucleated RBCs were obtained from 441 infants weighing more than 499 g and less than 1751 g. Neonatal cranial fontanel sonography was performed on days 3 and 7 of life, and neonates were divided into those with normal and abnormal sonographic findings. The nucleated RBCs were compared between these groups and between normal and abnormal groups matched for birth weight and gestational age. Mean gestational age, birth weight, birth weight percentile, Apgar score, respiratory distress syndrome and mortality were different between the infants with normal and abnormal ultrasound findings. The nucleated RBCs (per 100 white blood cells) were not different (40.5 +/- 126.8 versus 41.8 +/- 71.7, t = 0.09, P = .9). When we controlled for gestational age and birth weight, there was no significant difference between nucleated RBCs in those with normal and abnormal sonography (54.3 +/- 206.5 versus 41.4 +/- 72.0,t = 0.56, P = .6). In growth-restricted neonates, there was a significant increase in nucleated RBCs regardless of whether growth restriction was defined as tenth percentile or less, 25th percentile or less, or 50th percentile or less, even when we controlled for gestational age. Nucleated RBCs are not different in preterm infants with or without intraventricular hemorrhage and periventricular leukomalacia, even when one controls for gestational age and birth weight. There are significant elevations in nucleated RBCs in growth-restricted fetuses. Birth weight percentile must be considered when using nucleated RBCs as a marker of intrauterine hypoxia.

Renal tubular dysgenesis and very large cranial fontanels in a family with acrocephalosyndactyly S. C. type

We describe the first case of renal tubular dysgenesis in a newborn female who survived 15 days. The immunohistochemical and lectin binding studies confirmed the lack of proximal tubule differentiation. Electron microscopy showed undifferentiated tubular epithelium. Widely patent cranial fontanels were present in the proposita. The father and sister showed acrocephalosyndactyly Saethre-Chotzen type. The parents were not related and there was no familial history of renal pathology.

Ultrasound evaluation of complications in shunted hydrocephalus

In the infant the cranial and abdominal complications of ventriculoperitoneal shunting can be assessed by real-time ultrasound via the anterior cranial fontanelle or the abdominal wall. The possible complications are listed and eight cases document the spectrum.

A Contribution to the Morphology of the Teleostean Head Skeleton, based upon a Study of the Developing Skull of the Three-spined Stickleback (Gasterosteus aculeatus)

ABSTRACT 1. The cranial flexure, together with other features in the shape of the embryonic head skeleton in Teleosts, is probably a mechanical effect due to differences in the degree of distensibility between the dorsal and ventral surfaces of the brain, and to the presence of skeletal structures in close association with the latter (pp. 507—509). 2. The presence of an epiphysial bar, with consequent division of the large dorsal, cranial fontanelle into an anterior and a posterior portion, is a common feature among Teleosts during development (pp. 516, 517). 3. The Ostariophysi differ from all other Teleosts in the retention of this early developmental condition of the cranial roof in the adult (pp. 525, 526). 4. The intra-cranial notochord, so far from undergoing reduction, never at any stage ceases to grow (pp. 513, 516, 523). 5. In Gasterosteus, during embryonic life, those skeletal elements immediately concerned in the support of the jaws and operculum, and in the attachment of associated muscles, seem to undergo a considerable acceleration in the rate of development as compared with the rest of the head skeleton (pp. 534, 535). 6. Among Teleosts and the immediately related Ganoids, three types of palato-ethmoidal relationship exist (pp. 538, 539, 551—557). (a) The Panartete, in which the paiaume cartilage or its derivatives is attached to the ventral surface of the ethmoid for the whole length of this, from the parethmoid to the pre-ethmoid cornua, e. g. Amia, probably presented also by many Malacopterygii (Isospondyli). (b) The Disartete, in which the attachment is at the parethmoid and pre-ethmoid cornua, but not at any intermediate point, e. g. Esox, also presented by the Salmonidæ, Cyprinodontidæ, Acanthopterygii, and probably some Malacopterygii (Isospondyli). (c) The Acrartete, in which the attachment is confined solely to the pre-ethmoid cornua, e. g. Gasterosteus, and also presented by the Thoracostei, Scomberesoces, Plectognathi, Zanclidæ, Acronuridæ, and in a modified form by Lepidosteus. 7. The study of the adult anatomy and comparative ontogeny of the head skeleton in Elasmobranchs and Teleo-stomes seems to point to a common ancestral stock for these two great divergent branches of fishes. It presented among other features the following : A short embryonic life ; weak cranial flexure ; trabeculæ united to the extreme anterior end of the parachordals. A wholly cartilaginous cranium, possessing trabecular, parachordal, and occipital portions (pp. 560—562). A cranium having a large dorsal fontanelle, which may oi* may not have been divided by a transverse epiphysial bar. Also two lateral fontanelles for the passage of the optic, and possibly also the trigeminal and facial nerves. Also a ventral or pituitary fontanelle. Also a large opening between the cavum cranii and auditory capsule (pp. 562—568). A quadrate cartilage supporting a lower moveable jaw, formed by the union of two cartilages in the middle line, and bearing dorsally two, possibly three processes ; an anterior one, parallel to its fellow, and not united with it, but with the ethmoid plate, so that a moveable upper jaw did not exist; a middle one articulating with the trabeculæ, in the region lying between the optic and trigeminal nerves ; a posterior one articulating with the auditory capsule (pp. 568—573). A branchial apparatus consisting of at least five arches, already segmented into four parts. Balfour’s term Prolognathostoraata (81, p. 271) would be sufficiently expressive of such a type. 8. The manner of mandibular suspension in Teleosts is insufficiently described by the term Hyostylic (pp. 569, 570). 9. The Lophobranchii and Hemibranchii should no longer be kept in separate orders, for they together constitute a natural group, which may be designated the Thoracostei (pp. 575—579). 10. The Scomberesoces, through the Gasterosteoidei, approach more closely to the Thoracostei than do any other living Physoclisti, and seem to form with them a compact series, which may be provisionally spoken of as the Scomberesocine series (pp. 580, 581). 11. As judged by the study of the ethmoid and suspensorial regions, the Zanclidæ and Acronuridæ are closely allied to the Plectognathi, but the affinities of these forms must not be sought amongst living Physoclisti (pp. 582, 583).