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Biomedical subjects

C E Oyer

Publications and source records attributed to C E Oyer.

At least 19 recordsLinked to original sources
PubMed2000

Fatal intrauterine adenoviral endomyocarditis with aortic and pulmonary valve stenosis: diagnosis by polymerase chain reaction.

We report a case of fatal hydrops fetalis owing to adenoviral endomyocarditis with aortic and pulmonary valve stenosis. A 1850-g macerated male stillborn delivered 1 week after fetal ultrasonography showed hydrops, cardiomegaly, and possible aortic valve stenosis. Autopsy confirmed hydrops and showed thickened, fibrotic semilunar valves with stenosis. The myocardium was focally fibrotic with areas of calcification. Polymerase chain reaction study of myocardial and aortic valve tissue was positive for adenovirus. Intrauterine viral myocarditis has been reported only rarely, but cases owing to Coxsackie B virus, adenovirus, and parvovirus B19 have appeared in the literature. With the exception of rubella, viral causation of significant valvular lesions in humans has received scanty support in the literature. This report suggests a broader group of causative agents. HUM PATHOL 31:1433-1435.

Adenoviridae Infections↗
PubMed1998

First trimester pregnancy loss associated with varicella zoster virus infection: histological definition of a case.

Pathological demonstration of varicella infection in first trimester aborted tissue is reported. A 24-year-old primigravida manifested chickenpox infection about 38 days after her last menstrual period or at 24 days age of the embryo. The conceptus survived another 4 to 5 weeks. The macerated embryo and placental tissue revealed nuclear changes consistent with varicella infection. Immunohistochemical stains and electron microscopy were confirmatory.

Adult↗
PubMed1997

Ischemia-reperfusion injury in the intestines of newborn pigs.

Although the pathogenesis of necrotizing enterocolitis remains uncertain, ischemia appears to be an important contributing factor to the development of this disorder. Reperfusion plays a major role in ischemia-related injury, and oxygen free radicals produced during reperfusion most likely contribute to the injury. These oxidants can be generated during prostanoid metabolism, which increases during reperfusion of ischemic gut in adult subjects. The present study was designed to: 1) examine the effects of superior mesenteric artery occlusion, e.g. ischemia and reperfusion in vivo on the development of histopathologic intestinal injury; 2) determine whether products of arachidonic acid metabolism, e.g. prostanoids are increased during reperfusion of ischemic gut; and 3) determine whether oxygen free radical scavengers attenuate the injury in newborn pigs. Chronically catheterized placebo-pretreated newborn pigs exposed to ischemia-reperfusion, placebo-pretreated nonischemic control pigs, and polyethylene glycol-superoxide dismutase (SOD) plus polyethylene glycol-catalase (CAT)-pretreated, ischemic pigs were studied by examining changes in intestinal circulation, oxygenation, prostanoids, and tissue injury. In the placebo-pretreated pigs, intestinal blood flow decreased to very low levels during superior mesenteric artery occlusion. During reperfusion, blood flow increased, but remained below baseline. After ischemia, oxygen uptake returned to values that were similar to baseline. Intestinal efflux of the vasodilator 6-keto-prostaglandin F1alpha was evident (p < 0.05 versus no or zero efflux) during early reperfusion. Histopathologic scoring of terminal ileal samples showed significant mucosal necrosis, surface epithelial disruption, lamina propria congestion and hemorrhage, submucosal hemorrhage, edema, and increases in cells compared with the placebo-pretreated nonischemic pigs. In the SOD plus CAT-pretreated ischemic pigs, changes in intestinal blood flow, oxygen uptake, 6-keto-prostaglandin F1alpha efflux, and the pattern of the ileal tissue injury did not differ significantly from the placebo-pretreated ischemic pigs. In summary, superior mesenteric artery occlusion for 1 h and reperfusion for 2 h resulted in severe intestinal ischemia, early postocclusive limited increases in intestinal perfusion and oxygen uptake, efflux of vasodilating prostanoids during early reperfusion, and signs of ischemic tissue injury in the placebo- and SOD plus CAT-pretreated pigs. This study demonstrates that, after superior mesenteric artery occlusion and reperfusion, severe intestinal tissue injury is detected in vivo, prostanoid efflux increases, and SOD plus CAT given just before occlusion does not attenuate the extent of injury in newborn pigs.

Animals↗
PubMed1996

The detection of non-immune hydrops through second-trimester maternal serum screening.

The objective was to investigate whether non-immune hydrops in euploid pregnancies is associated with alterations in the second-trimester levels of maternal serum alpha-fetoprotein (AFP), unconjugated oestriol (uE3), and human chorionic gonadotropin (hCG). Ten singleton cases of fetal non-immune hydrops were identified. The aetiology and timing of onset of the earliest signs of non-immune hydrops, including polyhydramnios, in relation to maternal serum screening for Down syndrome were assessed. There was no clear relationship between the aetiology of non-immune hydrops and the analyte levels, as aetiologies varied widely. AFP levels were elevated overall (median = 1.78 MOM) and uE3 levels were unremarkable (median = 0.82 MOM). hCG levels were elevated (median = 3.53 MOM) when non-immune hydrops was present at the time of screening, but were unremarkable (median = 0.82 MOM) when the non-immune hydrops presented later. It is concluded that second-trimester non-immune hydrops is associated with elevated hCG levels.

Adult↗
PubMed1996

The lethal hemolytic mutation in beta I sigma 2 spectrin Providence yields a null phenotype in neonatal skeletal muscle.

Point mutations in beta I sigma 1 spectrin that impair the self-association of spectrin alpha beta heterodimers cause mild to severe hemolytic disease and erythrocyte shape abnormalities. Most such mutations act in a dominant negative fashion. One mutation that is particularly devastating is found in beta spectrin Providence. The Providence mutation replaces serine2019 with proline. Heterozygotes display microcytic and fragile erythrocytes; homozygotes die in the neonatal period. It has recently been determined that an alternative transcript of the same beta I sigma 1 spectrin gene expressed in erythroid lineage cells is the major spectrin in skeletal and cardiac muscle and in some neurons. Because the site of the Providence mutation is common to both beta I sigma 1 and beta I sigma 2 spectrin, defective protein must also be expressed in these tissues. Yet the impact of this or any other beta I spectrin mutation outside of the red cell is unexplored. To address this question with respect to skeletal muscle, we have examined the effects of the Providence mutation in cultured muscle cells, after adoptive gene transfer to adult mice, and in two infants homozygous for spectrin Providence. Transfection of the FLAG epitope tagged wild-type beta I sigma 2 or Providence beta I sigma 2 cDNA constructs into C2C12 myoblasts demonstrated by sedimentation velocity analysis that spectrin beta I sigma 2 Providence formed alpha II/-beta I sigma 2 heterodimers in muscle cells but not heterotetramers. Correspondingly, wild-type beta I sigma 2 spectrin formed both alpha II/beta I sigma 1 dimers and heterotetramers, although the proportion of dimers was surprisingly high, which suggested some limitation on self-association in the muscle environment. After adoptive gene transfer into adult mouse skeletal muscle in vivo, both the wild-type and mutant beta I sigma 2 spectrins assembled into a subsarcolemmal complex in a pattern indistinguishable from the native spectrin skeleton. Skeletal muscle taken at autopsy from two infants homozygous for spectrin Providence was normal histologically, as was the intracellular distribution of beta I sigma 2 spectrin as measured by immunoperoxidase staining. These patients also revealed no clinical evidence of myopathy or muscle wasting. It is unknown if they would have experienced dystrophic or myopathic changes if they had lived longer, although we believe that this is unlikely based on the absence of clinical myopathies in patients with other (albeit less severe) beta I spectrin self-association defects. Collectively, these observations indicate that the spectrin mutations that impact tetramer and oligomer formation, even those with a severe hemolytic phenotype, do not impact skeletal muscle function primarily because skeletal muscle does not use the oligomerizing feature of the spectrin skeleton to the same degree as erythrocytes.

Amino Acid Sequence↗
PubMed1995

Cardiac malformation in two infants with hypochondrogenesis.

Autopsy records from the Women and Infants' Hospital from January 1974 through January 1994 were reviewed to identify cardiac malformations in the presence of skeletal dysplasia. Of 24 cases of lethal fetal or neonatal osteochondrodysplasias, 4 were given diagnoses in which disorders of type II collagen are regarded as causative. These 4 were categorized in the spondyloepiphyseal dysplasia (SED) spectrum of disorders; specifically two patients with hypochondrogenesis and two with spondyloepiphyseal dysplasia congenita were identified. Defects in cardiac septation were noted in the 2 patients with hypochondrogenesis. No cardiovascular abnormalities were present in the remaining cases, which included thanatophoric dysplasia, osteogenesis imperfecta, and asphyxiating thoracic dystrophy. Although cardiovascular malformations have been described in other types of osteochondrodysplasias, e.g., short rib polydactyly syndrome type II and chondroectodermal (Ellis-van Creveld) dysplasia, congenital heart disease has not been described in hypochondrogenesis. Type II collagen, which has been found to be abnormal in some patients with hypochondrogenesis, is considered to have a limited tissue distribution, and has not been detected as yet in human myocardium. The findings presented here suggest that type II collagen may function in human cardiogenesis.

Abnormalities, Multiple↗
PubMed1995

The clinical utility of the perinatal autopsy.

OBJECTIVE: To evaluate the clinical utility of the perinatal autopsy in determining the cause of a perinatal death. DESIGN: Retrospective observational survey. SETTING: University-affiliated, private, tertiary care hospital, limited to obstetrics, gynecology, and neonatology. SUBJECTS: All fetal deaths and neonatal deaths from 1990 and 1991 at Women and Infants Hospital, Providence, RI, were reviewed. Fetal deaths with a gestational age of less than 20 weeks and neonatal deaths occurring more than 48 hours after birth were excluded. MAIN OUTCOME MEASURES: A clinical medical record review assessed the clinical diagnosis. Pathology records were reviewed independently. The clinical and autopsy diagnoses were compared and categorized as follows: (1) confirm (clinical and autopsy diagnoses concordant); (2) change (clinical and autopsy diagnoses discordant); (3) add (significant unexpected findings noted on the autopsy although the clinical diagnosis was not altered); (4) autopsy inconclusive; (5) autopsy not done or not available. RESULTS: Of 168 perinatal deaths, an autopsy was not obtained in 26.2% and was inconclusive in 24.2% of cases with an autopsy. Of 94 patients with conclusive autopsies, in 55.3%, the pathologic diagnosis confirmed the clinical diagnosis, and in 44.7%, it changed or significantly added to the clinical diagnosis. CONCLUSIONS: These findings support the clinical relevance of the perinatal autopsy. As few published reports directly address the specific yield of the autopsy among fetal and neonatal deaths, these results may be useful in counseling patients who are considering a perinatal autopsy.

Autopsy↗
PubMed1994

Relaxation of imprinting in trophoblastic disease.

Genomic imprinting--the uniparental-dependent transmittance of a genetic trait--has been accepted in recent years as a major mechanism in mammalian genetics. We studied the expression of the H19 gene, a parentally imprinted (maternally expressed) gene, by in situ hybridization in human placenta and trophoblastic disease. Expression was found to be abundant, in a decreasing order, in the intermediate trophoblast (villous and interstitial), the cytotrophoblast, and the syncytiotrophoblast. The villous stroma was also prominently labeled. Partial hydatidiform mole showed a similar pattern of expression as normal placenta. As expected, complete hydatidiform mole, whose genome consists of two haploid sets of paternal origin, was not labeled in the villous stroma and surrounding trophoblastic layer. However, some of the large mononuclear cells in the proliferating groups sprouting from the villous surface were strongly labeled. Prominent expression of H19 was found in placental site trophoblastic tumor and gestational choriocarcinoma. The phenomenon of emergence of expression of alleles subject to repression according to their gamete of origin is termed relaxation of imprinting, and is considered to be relevant to tumorigenesis. We suggest that the expression of the maternally expressed H19 gene in the androgenetic tissue of complete hydatidiform mole represents relaxation of imprinting and may be associated with its malignant potential.

Choriocarcinoma↗
PubMed1991

Cardiomyopathy and myocyte intranuclear inclusions in neuronal intranuclear inclusion disease: a case report.

Neuronal intranuclear inclusion disease (NIID) is a progressive, usually fatal degenerative neurologic condition characterized by eosinophilic, intranuclear inclusions in neurons of the central and peripheral nervous system. We report a boy with onset of disease manifestations at age 3 and death at age 9, who showed clinical and pathologic findings characteristic of NIID. The case is unique because of cardiomyopathy manifested 1 year prior to death. Postmortem findings confirmed the presence of cardiomyopathy and revealed intranuclear inclusions in myocytes. Neither nuclear inclusions in the myocardium nor cardiac involvement have previously been reported in NIID.

Cardiomyopathies↗
PubMedDate not supplied

Unusual combination of congenital heart defects in an infant with Noonan syndrome.

Congenital heart disease occurs in 35-50% of patients diagnosed with Noonan syndrome. We present an infant with an unusual combination of congenital heart defects not previously reported, including partial atrioventricular septal defect, polyvalvular dysplasia, and progressive hypertrophic cardiomyopathy. We discuss the possible interaction between these lesions that may have led to the patient's rapid demise.

Angiography↗