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Biomedical subjects

R C Truex

Publications and source records attributed to R C Truex.

At least 19 recordsLinked to original sources
PubMed1988

Monoamine alterations during experimental hydrocephalus in neonatal rats.

The present study was designed to determine the selected monoamine changes that occur during infantile hydrocephalus. Obstructive hydrocephalus was induced in newborn rats by injection of a suspension of kaolin into the 4th ventricle and cisterna magna. Eleven days later, experimental animals and their sham-operated littermate controls were killed and pieces of frontoparietal cortex, neostriatum, cerebellar vermis, and brain stem were processed for high performance liquid chromatography. Grossly, the lateral ventricles were extremely enlarged, the cerebral cortex was thinned, the neostriatum was compressed, and portions of the tectum and cerebellum were vacuolated. Decreases in norepinephrine (71%), dopamine (73%), and serotonin (50%) were observed in the cerebral cortex, neostriatum, and cerebellum, respectively. Brain stem norepinephrine and serotonin were increased 70% and 50%, respectively. These increases may indicate impairment of axonal transport or damage to projections from the locus ceruleus and raphe region. These preliminary results suggest that infantile hydrocephalus causes perturbations in the levels of different monoamines in several brain regions. Such changes may critically influence neuronal function and development, as well as the therapeutic management of hydrocephalus.

Animals↗
PubMed1987

Association of a ganglioneuroma with an arteriovenous malformation: case report.

The unusual concurrence of a brain tumor and an arteriovenous malformation (AVM) is discussed in this case report. A 12-year-old child presented with a severe headache, and an intracerebral mass was found on neuroradiological study. At operation, we encountered a superficial AVM, not shown on the computed tomogram or arteriogram. At a second procedure, a ganglioneuroma was removed. The literature on the concurrence of these two entities is reviewed; comments are made on the pathology of ganglion cell tumors.

Brain Neoplasms↗
PubMed1985

Neuronal effects of experimentally induced hydrocephalus in newborn rats.

To determine the effects of increased cerebrospinal fluid (CSF) pressure on neuronal morphology, obstructive hydrocephalus was induced by injecting kaolin into the fourth ventricle and cisterna magna of 1-day-old rats. The animals were sacrificed 10 to 12 days later, at which time severe ventriculomegaly and cortical thinning were apparent in the parieto-occipital region. Tissue from this area was processed by rapid Golgi methods. Well impregnated pyramidal neurons were examined by light microscopy, and their somatic and dendritic features compared to those of age-matched littermate controls. The somata of medium pyramidal neurons were unaffected, but their basilar dendrites had fewer branches and those that remained were shorter. A variable reduction in dendritic spines occurred, such that some branches were totally denuded while others exhibited spine densities similar to those seen in control animals. The most striking alteration was the occurrence of frequent dendritic varicosities. These enlargements of the dendritic shaft separated by extremely thin constrictions gave the affected segment a beaded appearance. Both dendritic spine loss and varicosity formation were most notable on distal portions of individual branches and within regions of the dendritic tree closest to the ventricular and meningeal surfaces. These alterations are consistent with other reports of dendritic changes associated with aging, mental retardation, and alcohol exposure. These observations suggest that hydrocephalus causes dendritic deterioration or retardation of dendritic maturation. The fact that neuronal morphology was not more severely affected may indicate that these effects are reversible.

Animals↗
PubMed1983

External obstructive hydrocephalus: a study of clinical and developmental aspects in ten children.

At this time there are few published cases on this problem, but we have found that the syndrome does seem to correct itself with time. As the patients become stronger and their age increases, they catch up with their peer group. A 1978 study by Robertson documented five of six children attaining normal levels of skills appropriately. In another recent study, Ment researched eighteen infants with seventeen eventually developing within normal limits. Shunting of CSF through surgical intervention does not seem to be needed. We hope to continue our study and follow these children on a long-term basis, seeking to find the total picture of this seemingly benign syndrome.

Brain↗
PubMed1981

Intracranial malignancy in patients with bilateral retinoblastoma.

Tumors from two patients with bilateral retinoblastoma and intracranial malignancies were studied from a clinical, histopathological, and an immunohistochemical standpoint. An antiserum derived against tissue cultured Y-79 retinoblastoma cells was utilized in order to examine the surface and cytoplasmic antigens of the two brain tumors, histopathologically diagnosed as an embryonal cell carcinoma (case 1), a pinealoblastoma (case 2), and one ocular retinoblastoma. The two brain tumors reacted with the antiserum to different degrees. In comparison, the ocular tumor reacted strongly. None of the tissues examined were found to contain retinal S- or P-antigen. The concept of retinoblastomas arising de novofrom the pineal gland and the association of intracranial malignancy occurring in retinoblastoma is stressed. The antigenic and immunologic relationships between normal retina and pineal gland and retinoblastoma, neuroblastoma, and pinealoblastomas are discussed.

Antigens, Neoplasm↗
PubMed1980

Computed tomography in primary craniosynostosis.

Computed tomography (CT) in primary craniosynostosis clearly demonstrated the superiority of CT in revealing the shape of the head, suture closure, and brain abnormalities and in follow-up after treatment.

Cranial Sutures↗
PubMed1978

Observations on the development of the human atrioventricular node and bundle.

This light microscopic study of the cardiac junctional tissues was based on 27 human embryos, fetuses and postnatal hearts. Evidence was presented that superficial and deep portions of the postnatal AV node were derived from two cellular primordia in the posterior wall of the common atrium at the 6-mm stage. The small right primordia was associated with the right venous valve and give rise to the loosely organized superficial AV node that extended posteriorly to the coronary sinus ostium. A larger left primordia formed the more compact deep subdivision of the AV node located against the anulus fibrosus. In most postnatal hearts the two subdivisions are partially or completely fused to form the adult AV node. Failure of the nodal primordia to fuse during cardiogenesis may result in two separate nodal cell aggregates above the anulus. The present observations provide a rational explanation for the two AV nodal masses described in the literature and an additional specimen that is illustrated in this communication. An AV bundle was first identified in a 13-mm embryo and appeared to be derived from large clear cells of the posterior AV canal. At 25 mm the bundle formed a broad band across the top of the IV septum and continued into both ventricles. At this stage multiple cell strands penetrated the endocardial cushion to connect the AV bundle to the two nodal primordia. Failure of normal fusion between the AV node primordia and AV bundle can result in a variety of junctional anomalies including congenital heart block.

Atrioventricular Node↗
PubMed1977

Association of maternal systemic lupus erythematosus with congenital complete heart block.

Infants born to mothers with disseminated lupus erythematosus occasionally have transient manifestations of the maternal disease. In six infants with congenital heart block born to mothers with systemic lupus erythematosus we postulated a causative relation. In one of the infants a post-mortem study of the conduction system suggested faulty embryonic development of the atrioventricular node with an abnormally thick annulus fibrosus and the effects of early inflammatory changes. Two of the infants had a cardiomyopathy and three, associated congenital heart disease.

Adult↗
PubMed1977

The dorsal motor nucleus of the vagus nerve of the cat: localization of preganglionic neurons by quantitative histological methods.

The dorsal motor nucleus of the vagus nerve (DMX) of adult cats and young kittens was studied by quantitative light microscopic methods. In normal animals, the DMX was found to contain no distinct subgroupings of neurons, based on somatic volume or Nissl pattern. Retrograde perikaryal responses to axotomy of neurons in the DMX were found to be of a more subtle nature than those seen in other types of neurons. Quantitative methodology applied to the axotomy than could be obtained by routine microscopic observations. Changes which occurred included a slight chromatolytic reaction, and a decrease in the volume of the nucleus followed by an increase in somatic volume. These morphological alterations were affected by the factors of age of the animal, time after axotomy, and length of the intact proximal axon stump. More pronounced perikaryal changes occurred when the vagus nerve was recut at a more proximal level five days after the first vagotomy. Interpretation of the data yielded the conclusion that most if not all neurons of the ipsilateral DMX contribute axons to the cervical vagus nerve. In addition, at least 10% of the neurons on the side contralateral to vagotomy showed signs of retrograde reaction. It was therefore concluded that there exists in the vagus nerve a population of axons with cell bodies located in the contralateral DMX.

Animals↗
PubMed1977

Anterior sacral meningocele: report of five cases and review of the literature.

Five new cases of anterior sacral meningocele are presented, including one secondary to neurofibromatosis, a previously undescribed association. The literature is reviewed, drawing attention to the relationship between anterior sacral meningocele, sacral dysgenesis, and other congenital anomalies. Special consideration is given to the clinical features of this entity, as well as to the techniques and results of surgical management.

Abnormalities, Multiple↗
PubMed1977

Spinal injury at the level of the third and fourth cervical vertebrae from football.

Acute traumatic lesions of the spine at the third and fourth cervical levels without associated fracture are not common. The eight lesions in this report occurred as a result of injuries sustained during tackle football. They included acute intervertebral disc herniation, anterior subluxation of the third cervical vertebra on the fourth, unilateral dislocation of the joint between the articular processes, and bilateral dislocation of the joints between the articular processes. The mechanism of injury was the use of the top or crown of the helmet as the primary point of contact in a high-impact collision when blocking, tackling, or head-butting. To avoid a seemingly inevitable increase in the incidence of these lesions occurring from tackle football, coaches and officials will have to modify the current techniques of blocking tackling, and head-butting.

Adolescent↗