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Biomedical subjects

B S Carson

Publications and source records attributed to B S Carson.

63 records · Page 4Linked to original sources
PubMed1982

Improved rabbit brain tumor model amenable to diagnostic radiographic procedures.

The VX2 carcinoma was used to create a rabbit brain tumor model. VX2 tumors were chemically dissociated and suspended in liquid medium. Twenty-five microliters of the tumor suspension containing 3 X 10(3), 3 X 10(4), or 3 X 10(5) viable tumor cells were injected through cranial burr holes 6 mm into the right frontoparietal lobes of 17 rabbits. Fifteen of these developed histologically documented nodular intraparenchymal tumors. Tumors were demonstrable with cerebral computed tomographic scans and by cerebral angiography. The feasibility of surgical resection of lesions using the fluorescein staining technique was also demonstrated. This animal brain tumor model is suitable for neuro-oncology research focusing on imaging and therapeutic techniques.

Animals↗
PubMed1978

Insulin secretion in fetal and newborn sheep.

The relationships between arterial plasma insulin, glucose, and fructose concentrations during the fed and fasted state were studied in seven fetal lambs and their mothers. A significant correlation between insulin and glucose concentration was noted in all fetal lambs and in their mothers. Fetal sensitivity to glucose, as measured by the slopes of the insulin-response curves, was equal to that of the adult although the fetal response was shifted to the left of the maternal. Glucose infusion in four fetal lambs caused significant insulin elevations but no early insulin response (phase I). Maternal fasting caused no alteration in glucose-induced response in the fetus. Similar glucose infusions in newborn and 1-mo-old lambs demonstrated significant early-phase insulin secretion. Basal insulin to glucose ratios were consistent with an adult pattern as early as 3 days after birth.

Animals↗
PubMed1977

Monocyte-macrophage function in the newborn.

Analysis of 20 human cord blood samples for monocyte-macrophage function demonstrates a selective defect in monocyte cellular chemotaxis. Monocyte bacterial phagocytosis, phagocytosis of paraffin oil particles, and bacterial killing of staphylococcus 502A were normal when compared with 30 healthy young adult controls. Impaired response of neonatal monocytes to chemotactants is an additional host defense defect that may help explain the undue susceptibility of neonates to certain infectious agents.

Adult↗
PubMed1976

Combined obstetric and pediatric approach to prevent meconium aspiration syndrome.

Routine intrapartum pharyngeal suctioning with a DeLee catheter of infants with meconium staining has significantly reduced the incidence and severity of meconium aspiration syndrome (MAS). There have been no adverse sequelae to this procedure, which is carried out while the infant's head is on the perineum, prior to the onset of respirations. Routine suctioning of the trachea under direct vision after delivery is rarely necessary but should be done if meconium is visualized at the vocal cords. Tracheobronchial lavage with saline may add to the respiratory morbidity. No deaths or severe cases of MAS have occurred since institution of the obstetric suctioning procedure.

Female↗
PubMedDate not supplied

Ototoxicity of carboplatin delivered locally in a monkey brainstem.

Ototoxicity is a common side effect of platinum-based chemotherapy. Intratumoral drug delivery theoretically could reduce the ototoxic effects of systemic drug infusions. However, local delivery to central nervous system (CNS) tumors might promote ototoxicity through drug release into cerebrospinal fluid (CSF). This report describes an examination of the cytoarchitecture of vestibular cells of cynomolgus monkeys that had chronic brainstem infusions with the maximum tolerated dose (MTD) of carboplatin. The brainstems of adult monkeys were infused for 30 days at 0.42 mu l/h with 0.025 to 0.25 mg/kg (MTD) of carboplatin. The vestibular sensory epithelia of eight drug-treated animals were isolated for microscopic examination of vestibular hair cells and support cells. Local infusions produced chronic elevated CSF levels of platinum, neurological symptoms, and radiographic evidence of pontine injury. Histology revealed significant cell damage at the infusion sites. Microscopic examinations of vestibular support cells and hair cells demonstrate a small reduction in cell counts in the drug-treated monkeys compared to a noninfused control animal. Parametric and nonparametric tests show no effect of dose in predicting the vestibular cell counts. In this single study of eight monkeys, a dose-dependent reduction of vestibular hair cells or support cells was not observed in animals infused with brainstem infusions of 0.025 to 0.25 mg/kg of carboplatin.

Animals↗
PubMedDate not supplied

Progressive unilateral encephalopathy of childhood (Rasmussen's syndrome): a reappraisal.

Twelve children with Rasmussen's encephalitis underwent hemispherectomy and have been followed for an average of 9.15 years. Our decision-making process leads to early, rather than late operation. Because hemiplegia is inevitable with or without operation, earlier operation may allow such children to resume a more normal life. We postulate that earlier operation may prevent some of the intellectual decline that accompanies the continued seizures and their treatment. In view of the variable pathologic findings and lack of evidence of a viral etiology, we suggest either use of the term "progressive unilateral encephalopathy of childhood" or "Rasmussen's syndrome" in recognition of its heritage.

Adult↗
PubMedDate not supplied

A heterotopic cerebellum presenting as a suprasellar mass with associated nasopharyngeal teratoma.

We present a case of nasopharyngeal teratoma that was discovered in association with a suprasellar heterotopic cerebellum in a newborn. Well-differentiated, heterotopic, cerebellar masses have been reported in the orbits, spine, and frontal encephalocele but not, to our knowledge, in the suprasellar region. In this report, we describe the imaging findings and discuss the possible origins of the two masses discovered in this case.

Adult↗