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Biomedical subjects

R M Shuman

Publications and source records attributed to R M Shuman.

35 records · Page 2Linked to original sources
PubMed1980

Periventricular leukomalacia. A one-year autopsy study.

We review the frequency and distribution of periventricular leukomalacia (PVL) in consecutive neonatal autopsies in a complete 12-month period. Periventricular leukomalacia occurred in 88% of the high-risk infants. The demographic factors that define risk are a birth weight between 900 and 2,200 g and a survival of six days or more. Virtually all infants with PVL suffered severe clinical insults, and/or had additional necrotic lesions in their viscera. Preferentially, PVL occurs in the cerebral axons in the occipital and sensory-motor radiations. The frequency with which this lesion is found at autopsy may correspond to the frequency with which visual, auditory, and motor dysfunctions occur in surviving premature infants. Electrophysiologic investigations of the high-risk premature infant seem warranted.

Birth Injuries↗
PubMed1979

Cerebral infarcts with arterial occlusion in neonates.

Among 592 infants examined at autopsy during a four-year period, 32 (5.4%) had cerebral infarcts. Excluded were cases of traumatic hemorrhages and softening, periventricular leukomalacia, venous lesions, and any mass, including encephaloceles, with arterial distortion and infarction. Histological abnormalities were similar to those of infarcts in adults. Relatively advanced histopathological changes in some infants living only a few hours indicated that some infarctions may have occured in utero. The most common cause of arterial occlusion was embolization, with sepsis and disseminated intravascular coagulation playing a major role. The brains of term neonates were more frequently involved than those of premature infants. Multiple small infarcts occurred more often in premature infants. In most cases autonomic dysfunction with prolonged apnea, episodic seizures, and metabolic acidosis were the major associated clinical features, rather than focal neurological deficits. Similar cerebral infarcts in infants who survive with less severe systemic complications may lead to porencephaly, hemiplegia, mental and motor retardation, and recurrent seizures.

Brain↗
PubMed1978

The neuropathology of the nonketotic and ketotic hyperglycinemias: three cases.

Abnormal dysmyelination constitutes a pathoanatomic basis for the mental retardation in two different aminoacidopathies, nonketotic hyperglycinemia and ketotic hyperglycinemia. In both conditions myelin is decreased in amount and vacuolated. Similar patterns of dysmyelination in different aminoacidopathies suggest that abnormal myelination results from inadequate synthesis of myelin proteins.

Amino Acid Metabolism, Inborn Errors↗
PubMed1977

Pneumocephalus secondary to cerebrobronchial fistula formed by a ventriculoatrial shunt. Case report.

A case is presented in which the atrial tip of a ventriculoatrial shunt formed a fistulous connection with the bronchial tree in a child. This resulted in acute bronchopneumonia, pneumocephalus, and ventriculitis. Pneumocephalus was created by an artificial respirator forcing air along the shunt tract during treatment of bronchopneumonia. Sudden death was related to transtentorial herniation. The diagnosis of a cerebrobronchial fistula should be entertained in shunt patients with respiratory distress and radiographic pulmonary densities unresponsive to antibiotics.

Bronchial Fistula↗
PubMed1975

Neurotoxicity of topically applied hexachlorophene in the young rat.

Young rats 6 to 22 days of age are extremely susceptible to the neurotoxic effects of hexachlorophene given as a daily bath of undiluted antiseptic detergent containing 3% hexachlorophene (pHiso-Hex). At this age, most rats are clinically and histologically damaged by as few as two daily baths. Younger rats are relatively resistant, probably because they have less myelin to be affected; older rats cannot be poisoned by this route, probably because the more mature liver excretes the drug more effectively. Age-dose-response curves in rats are similar to those in humans. This experimental model is potentially useful in defining other characteristics of this drug.

Administration, Topical↗
PubMed1975

Neurotoxicity of hexachlorophene in humans. II. A clinicopathological study of 46 premature infants.

To assess neurotoxic effects of hexachlorophene in the human population previously shown to be most at risk, a blind clinicopathological analysis was made of all premature infants under 1,400 gm birth weight who survived at least four days and were examined by autopsy over a 7.5-year period. Repeated whole-body bathing of premature newborn infants in 3% hexachlorophene-bearing soap (undiluted pHisoHex) shows a significant statistical association with a vacuolar encephalopathy of the brain stem reticular formation. The prevalence of the vacuolar encephalopathy in premature infants on whom we have adequate brain stem histological information appears to be related to the number of exposures to hexachlorophene, the concentration of hexachlorophene, the thoroughness of rinsing, and other factors (including exposure to ultraviolet light).

Administration, Topical↗
PubMed1975

The biology of childhood ependymomas.

The biology of 74 childhood ependymomas has been retrospectively investigated in total population samples from three hospitals in two cities. Regardless of the tumor's site of origin, the prognosis is grim. No child has been cured by surgery alone. The symptom-free interval after surgery is a first-order function of the age at diagnosis. The criteria for cure are best approximated by Collins "law," in terms of which there are apparently only three cured patients in this study. Intracranial ependymomas are best treated by careful excision of the tumor and radiation of a generous area to a total dose of at least 4,500 rads over a 60-day period. Radiation of the entire neuraxis appears to be indicated only in those few cases that can be considered malignant microscopically.

Adolescent↗
PubMedDate not supplied

Partial agenesis of the anterior corpus callosum: correlation between appearance, imaging, and neuropathology.

Two patients with partial (semilobar) holotelencephaly are reported with apparent partial agenesis of the corpora callosa. These patients are of interest because they appear to possess the posterior portion of the corpus callosum but not its anterior component. Because the corpus callosum develops in the commissural plate rostrally and is elaborated in a rostral-caudal gradient, this apparent lack of the rostral component is embryologically puzzling. The neuropathologic studies of 1 patient resolved the apparent discrepancy between magnetic resonance imaging and embryology of the corpus callosum. With these data, we addressed the embryologic factors that may explain this malformation.

Abnormalities, Multiple↗
PubMedDate not supplied

Cerebral degenerations producing dementia: importance of neuropathologic confirmation of clinical diagnoses.

Dementia is a major public health concern with our increasing elderly population and currently affects more than three million Americans at an annual cost of $50 billion. The marked overlap in symptomatology between Alzheimer's disease and other primary parenchymal degenerations makes antemortem diagnosis based on clinical assessment tentative at best, with error rates of 25% commonly reported. Accurate diagnosis is of vital importance in order to improve our understanding of these illnesses, evaluate potential therapies, and provide appropriate genetic counseling to family members. Direct neuropathologic examination at autopsy is currently the only reliable method for assuring accurate diagnosis, and should be undertaken in all demented patients. To illustrate the importance of these principles, we present three patients who were clinically diagnosed with Alzheimer's disease, and subsequently found to have other dementing illnesses by careful postmortem neuropathologic examination.

Adult↗
PubMedDate not supplied

Fetal alcohol myopathy.

A unique myopathic process in three flaccid, hypotonic, and weak neonates born to alcoholic mothers was investigated. In utero activity was depressed in all 3 cases. The muscle biopsies showed hypotrophy, dominance of type II fibers, and central nuclei. There was marked sarcomeric dysplasia at the ultrastructural level. Sarcomeres were of variable length and diameters; Z-band material with actin persisted in a coagulum of granulofilamentous debris; the number of myosin filaments was decreased. The degree to which myocytes were affected varied from focal to holocellular dysplasia. The disorder at the ultrastructural level in these damaged muscles from infants with the fetal alcohol syndrome is a unique constellation, warranting the term "fetal alcohol myopathy."

Female↗
PubMedDate not supplied

Immune response of chickens inoculated with a recombinant avian leukosis virus.

Specific-pathogen-free embryos (18-day incubation) and hatched chicks were inoculated with a recombinant avian leukosis virus (ALV) produced by recombinant DNA techniques. Enzyme-linked immunosorbent assays were used to measure the production of viral-protein-specific antibody and the viral protein, p27, in the serum at 2, 5, 8, 14, and 20 weeks of age. Of the inoculated chickens surviving to 20 weeks, 64% produced viral-protein-specific antibodies and 42% transiently produced the viral protein, p27. Chickens inoculated as embryos did not differ significantly from those inoculated at hatch with respect to antibody and viral protein production. Antibody production peaked at 5 weeks postinoculation and declined over the remaining 15 weeks of the study. No evidence of chronic tolerant infection or mortality due to neoplastic disease was found.

Animals↗
PubMedDate not supplied

Resistance of chickens to Rous sarcoma virus challenge following immunization with a recombinant avian leukosis virus.

An attenuated recombinant avian leukosis virus (ALV) produced by recombinant DNA techniques was examined for its ability to provide resistance to Rous sarcoma virus (RSV) challenge. Specific-pathogen-free chicken embryos (18-day incubation) and hatched chicks inoculated with recombinant ALV produced significantly smaller tumors than sham-inoculated controls upon challenge with RSV 2 weeks postinoculation; inoculation with RAV-1 produced similar results. Specific-pathogen-free hens inoculated with recombinant ALV produced viral-protein-specific antibody that was transmitted to 100% of the progeny, as detected by enzyme-linked immunosorbent assay. Progeny of the inoculated hens produced significantly fewer tumors than sham-inoculated controls upon challenge with RSV at hatch, indicating that maternal antibody may be a factor in resistance to tumor development.

Animals↗