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Biomedical subjects

W M Chadduck

Publications and source records attributed to W M Chadduck.

At least 37 records · Page 2Linked to original sources
PubMed1992

Cytogenetic findings in a case of pediatric glioblastoma.

We report a patient with glioblastoma multiforme (GBM) which showed stable and unstable telomeric associations involving the short arms of chromosomes 4 and 7. The karyotype was hyperdiploid, with chromosome numbers ranging from 84 to 87 in all cells, and showed a single stemline with variations in the number of marker chromosomes, teleomeric associations, and double minutes (dmin). The karyotype designation is 83-86,XX,-X,rea(X),-4,tas(4;7)(p16;?p22),der(6)t(6;?)(p21;?), -8, -9, der(9)t(9;?)(?p11;?), dup(9)(p12p23), -10 x 2, del(10)(p11), -11,del(11)(p11), -12, der(12)t(12;?) (p13;?),-13, -14 x 2,der(14)t(14;?) (p11;?), -16 x 2, -19, -21 x 2, -22 x 2, + 9-13mar, + dmin. Loss of the short arm of chromosome 10, structural aberrations of the short arm of chromosome 9, and dmin are consistent findings in GBM, whereas the high chromosome number is less common. Chromosome instability associated with the phenomenon of telomeric association/fusion has not been reported in GBM.

Adolescent↗
PubMed1992

Meningioma and sagittal craniosynostosis in an infant: case report.

The occurrence of a frontal base meningioma in a 3-month-old infant seen for the treatment of sagittal craniosynostosis is reported. The association of the two lesions is of interest both because it is unique and may lend support to theories of the cause of some forms of craniosynostosis.

Age Factors↗
PubMed1992

The subarachnoid spaces in craniosynostosis.

A review of 85 patients with various forms of craniosynostosis showed predictable patterns of dilatation of the subarachnoid spaces in regions of compensatory skull growth. The characteristic pattern in sagittal synostosis (43 patients) included dilatation of the frontal and occipital subarachnoid spaces associated with the elongation of the anteroposterior dimension of the skull and widening of the interhemispheric fissure. In 11 patients with unilateral coronal synostosis, dilatations of the subarachnoid spaces over the contralateral frontal lobe, the sylvian regions, and the ipsilateral temporal lobe tip were consistent with the skull changes of contralateral frontal bossing, increased bitemporal dimension, and elevation of the sphenoid wing, respectively. Four patients with bilateral coronal synostosis also had enlarged subarachnoid spaces high over the convexities of the brain consistent with the towering configuration of the skull. Four patients with true lambdoid synostosis had dilatation of the subarachnoid space only over the ipsilateral frontal lobe associated with compensatory bossing of the frontal bone. Ten of 14 patients with lambdoid deformities had bilateral enlargement of the subarachnoid spaces suggesting brain atrophy and an underlying motor delay accounting for the position-induced skull changes. The findings suggest that focal hydrodynamic mechanisms are involved in the compensatory skull changes seen in craniosynostosis.

Atrophy↗
PubMed1992

Diagnosis and management of the tethered cord syndrome.

Tethering of the spinal cord can occur from a thickened filum terminale, scarring due to myelomeningocele repair, lipomas or diastematomyelia. The typical presentation is a lumbar cutaneous defect, enuresis, unexplained back or leg pain, foot deformities, leg length discrepancies or scoliosis. Spinal ultrasound in neonates and MRI in older children offers ready diagnosis. With laser and microneurosurgical techniques, repair of these defects is safe and effective. The authors recommend that any infant having a mid-line lumbar cutaneous abnormality, such as a hemangioma, lipoma, hair patch or dimple, be evaluated to rule out tethering of the spinal cord.

Child↗
PubMed1991

Transcranial Doppler ultrasonography for the evaluation of shunt malfunction in pediatric patients.

Previous studies have demonstrated a high correlation between hydrocephalus and the resistive index (RI), as determined by transcranial Doppler ultrasonography. Measurements of RI, calculated by dividing the difference between the peak systolic velocity and the end-diastolic velocity by the peak systolic velocity, were attempted in 55 pediatric patients during evaluations for ventriculoperitoneal shunt malfunctions; values were obtained in 52. Indications of shunt malfunction included both clinical and radiographic evidence of increased intracranial pressure. Eleven patients, determined to have functional shunts both by clinical criteria and subsequent outcome, had RIs of 47 +/- 5 (average +/- 1 standard deviation). Shunt malfunctions were confirmed in 41 patients. Prior to shunt revisions, these 41 patients had RIs of 71 +/- 10%; following revision, the RIs fell to 53 +/- 12%. Nine patients had had pre-malfunction RIs of 48 +/- 11% obtained during routine follow-ups; when they subsequently had shunt malfunctions, their RIs had significantly increased. Four of the 41 patients with shunt malfunctions had essentially normal RIs (52 +/- 7%), but had fluid tracking along the shunt; in these, RIs were essentially unaffected by shunt revision. For comparison, 119 pediatric patients with clinically functional ventriculoperitoneal shunts had RIs of 50 +/- 9%. The data, statistically significant with a P value of less than 0.001, showed a correlation between elevated RIs and shunt malfunction; thus, transcranial Doppler ultrasonography is a practical, non-invasive technique useful in the diagnosis of ventriculoperitoneal shunt malfunction.

Adolescent↗
PubMed1991

Evolution of tumor chromosome abnormalities after therapy in a pediatric astrocytoma.

Chromosome studies originally performed on a patient with an untreated pontine astrocytoma showed a trisomy for 1q as the sole chromosome aberration. After the patient received radiation and chemotherapy, subsequent study indicated the presence of the original trisomy for 1q, as well as trisomy for chromosomes 2, 3q, and 17, in a tumor that now, histologically, is glioblastoma multiforme. In addition to the numerical aberrations, chromosome rearrangements were observed, involving translocation breakpoints that have been reported as "hot spots" associated with the clastogenetic effect of ionizing radiation.

Astrocytoma↗
PubMed1991

Molecular cytogenetic analysis of a medulloblastoma with isochromosome 17 and double minutes.

Cytogenetic analysis of a medulloblastoma revealed two abnormal cell lines of 48,XY, +8, +8, -14, +der(14)t(1;14)(q11;p11),i(17q) and 51,XY, +5, +6, +8, +8, -14 + 20, +der (14)t(1;14)(q11;p11),i(17q), + dmin. The finding of double minute chromosomes in some medulloblastomas has been associated with amplification of the c-myc or N-myc oncogenes. We were unable to detect gene amplification with these probes by Southern blot analysis.

Blotting, Southern↗
PubMed1991

Silastic duraplasty in pediatric patients.

The role of adhesions in the retethering of the neural elements after surgical treatment of spinal dysraphism has produced refinements in the technique of the closure of the neural tube. Silastic, because of its relative inert property, has been used for duraplasty, but a few reports of late complications of hemorrhage or fibrotic capsule formation have caused concern over its use. We report 33 patients with the following diagnoses--eight spinal lipomyelomeningoceles, three myelomeningoceles, six symptomatic Chiari II malformations, seven tethered cords, six spinal cord tumors, two diastematomyelia, and one cerebellar astrocytoma--in whom Silastic dural grafts were used to prevent the adherence of neural structures to the overlying tissues. Our surgical technique is presented here. The patients have been observed for up to 6 years. Only one became infected, was treated with antibiotics without graft removal, and has remained without sequelae for over 3 years. One had an incidental pseudomeningocele that was noted on follow-up magnetic resonance imaging scan that was not clinically apparent. There have been no hemorrhages, leakage of cerebrospinal fluid, nor other complications from using nonreinforced Silastic sheeting. In one patient, Dacron-reinforced Silastic was used and, upon reexploration, a marked fibroblastic response was noted. A review of the literature suggests that fibrotic complications are related to this Dacron-reinforced Silastic. The hemorrhagic complications that were reported occurred in instances where Silastic grafts were large and no technical modifications were made preventively. We conclude that the use of nonreinforced Silastic dural grafts, with appropriate technical modifications in surgical technique, is safe and may prevent retethering of neural tissues in a variety of neurosurgical lesions.

Child↗
PubMed1991

Selective posterior rhizotomy for relief of spasticity.

Results of sensory rhizotomy for the treatment of spasticity have been dramatically improved by newer microsurgical techniques employing intraoperative electrophysiological monitoring. This is now the treatment of choice for spasticity related to cerebral palsy. The goal of surgery is to achieve a permanent reduction in spasticity thereby improving ambulation and activities of daily living.

Adolescent↗
PubMed1990

Progression of chromosome abnormalities after radiation therapy in a patient with Askin's tumor.

A patient previously reported to have Ewing's sarcoma showed a t(11;22) (q23;q11) and spontaneous expression of fra(11)(q23) [1]. Subsequent review of pathologic specimen indicated, however, that it was an Askin's tumor. Reciprocal translocations of chromosomes 11 and 22 are the most common cytogenetic abnormalities in Ewing's sarcoma and the related Askin's tumor. After radiation therapy of a residual metastatic brain lesion, subsequent studies of the recurrent brain tumor indicated the presence of the original translocations as well as five new reciprocal translocations and two deleted segments (9p-, 10p-). The new chromosome abnormalities were consistently found, indicating that progression of the tumor was clonal. The newly observed clonal aberrations were considered secondary in nature. A relationship between craniocerebral irradiation and development of brain tumors has been reported in several studies, but the mechanism for tumor induction has not yet been elucidated. It is important that the role of radiation therapy in the evolutionary process of chromosomal changes be studied in a large group of similar cases.

Adolescent↗
PubMed1990

Trisomy for chromosome 1q in a pontine astrocytoma.

Reports of single chromosome abnormalities in pediatric brain tumors are rare. We report a 6-year-old patient with a malignant astrocytoma who had trisomy for the long arm of chromosome 1 as the sole chromosome abnormality.

Astrocytoma↗
PubMed1990

Screening spinal ultrasound in newborns with neural tube defects.

Twenty-six newborns with spina bifida had complete spinal ultrasound (US) prior to initial surgical repair of the neural tube defects. Associated anomalies were found on screening US in seven infants and included diastematomyelia (two cases), hydromyelia (two cases), and dural fat deposits (three cases). Initial surgical therapy was altered in one infant with diastematomyelia. Four closed simple meningoceles showed no internal neural elements on US and none were found at surgery.

Humans↗
PubMed1989

Postdelivery head bleeding in hemophilic neonates. Causes and management.

During a 12-month period, four of the five infants with hemophilia known to have been born in Arkansas were examined for head bleeding. Three of the infants had had traumatic delivery, with use of low forceps in two and vacuum extraction in one. In the fourth patient, hemophilia was prenatally diagnosed, and vaginal delivery resulted in cephalohematoma. Diagnosis was delayed in three patients, including one with a family history of hemophilia. Central nervous system bleeding may be more common in hemophilic neonates than has been presumed. Pregnancy management should include consideration of family history of bleeding disorders and carrier testing in appropriate cases. In confirmed carriers, prenatal diagnosis is justified to allow choice of the least traumatic delivery method. Any term neonate with intracranial hemorrhage should be treated as being possibly hemophilic until proved otherwise.

Cerebral Hemorrhage↗
PubMed1989

MRI in the evaluation of spina bifida patients in the remote period after meningomyelocele repair.

MRI was performed on 22 patients ranging in age from 3 months to 16 years who had closure of their meningomyelocele shortly after birth. These patients had developed new clinical findings suggestive of spinal cord dysfunction. MRI showed low placement of the spinal cord in all 22. Six patients had lipomas, five had diastematomyelia and six had hydromyelia. Four patients had an obviously dysplastic terminal cord.

Adolescent↗
PubMed1989

Cranial Doppler ultrasonography correlates with criteria for ventriculoperitoneal shunting.

Using pulsed Doppler ultrasound through the sonic window of the anterior fontanelle in infants, 46 children with ventriculomegaly had sequential evaluations of Resistive Index for comparison with the need for ventriculoperitoneal shunting. Hydrocephalus was associated with myelomeningocele in 17 patients and posthemorrhagic, postmeningitic, or congenital hydrocephalus accounted for the rest. The Resistive Index was obtained by dividing the difference between the peak systolic and end diastolic frequencies by the systolic frequency. Criteria for shunting included massive ventriculomegaly, increasing ventriculomegaly with an abnormal increase in head circumference, and clinical evidence of symptomatic hydrocephalus. Those patients requiring shunts had a Resistive Index of 84 +/- 13% prior to shunting. The Resistive Index fell to 72 +/- 11% postshunting with the difference being statistically significant at p less than 0.001. Moreover, the postshunting values compared favorably to data on 29 normal newborns, having Resistive Indices of 71 +/- 7% and to the Resistive Indices of three patients never shunted who had values of 74%, 66%, and 71%. Variations included primarily low Resistive Indices in myelomeningocele patients whose ventricles were decompressed by the leaking spinal lesions. Resistive Index used in conjunction with clinical observations may be extremely helpful not only in predicting the need for ventriculoperitoneal shunt, but also in evaluating children suspected of shunt malfunctions.

Cerebral Angiography↗