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Biomedical subjects

E A Roberts

Publications and source records attributed to E A Roberts.

At least 91 records · Page 5Linked to original sources
PubMed1989

Mesenchymal hamartoma in a 10-month-old infant: appearance by magnetic resonance imaging.

A previously well 10-month-old infant boy presented with a large hepatic tumor. Its sonographic and computed tomographic appearances were similar to those reportedly found in mesenchymal hamartomas. Magnetic resonance (MR) imaging showed a multiseptated mass with fluid-filled compartments and some displacement of major intra-abdominal vessels. This appears to be the first report of MR imaging of a mesenchymal hamartoma.

Hamartoma↗
PubMed1989

Multiple focal nodular hyperplasia of the liver associated with vascular malformations of various organs and neoplasia of the brain: a new syndrome.

Focal nodular hyperplasia (FNH) is a lesion of the liver in which a large anomalous artery is located within a region of hyperplastic hepatic parenchyma. Patients with FNH commonly have other lesions, often vascular in nature, in the liver or other organs. We have noted that these associated lesions almost always occur in patients with multiple FNH. We therefore studied 27 autopsied patients with FNH. All 13 with multiple FNH had other lesions such as hemangioma of liver, meningioma, astrocytoma, telangiectasis of the brain, berry aneurysm, dysplastic systemic arteries, and portal vein atresia. One patient had several of these lesions including multiple FNH, meningioma, astrocytoma, vascular malformation of the brain stem, and hemangioma of the liver. In contrast, among the 14 patients with solitary FNH there were no associated lesions, except for hepatic hemangioma in one patient. The prevalence of this syndrome was estimated by examination of 2500 serial autopsies and autopsies with various components of the syndrome. On review of 73 consecutive autopsies with meningioma, three had multiple FNH, compared with seven of 2500 consecutive adult autopsies (P less than 0.001). Multiple FNH was found in two of 83 autopsies with astrocytoma (P less than 0.05) and in one of 139 autopsies with berry aneurysm (not significant). We describe a telangiectatic subtype of FNH which occurs in this syndrome as well as in a minority of patients with solitary FNH. The existence and character of this syndrome suggest that there may be an underlying systemic abnormality in some patients having components of the syndrome. Investigation of patients with multiple FNH lesions may reveal significant treatable lesions.

Adolescent↗
PubMed1988

Hepatic abscess and cystic fibrosis.

Extrapulmonary infection is rare in cystic fibrosis. We describe two adult patients with cystic fibrosis whose course was complicated by the development of liver abscesses. The possible aetiology of these abscesses is discussed and the diagnosis, treatment and prognosis of pyogenic hepatic abscess is briefly reviewed.

Adult↗
PubMed1987

Ah receptor in human placenta: stabilization by molybdate and characterization of binding of 2,3,7,8-tetrachlorodibenzo-p-dioxin, 3-methylcholanthrene, and benzo(a)pyrene.

Aryl hydrocarbon hydroxylase (AHH, cytochrome P1-450) is highly inducible in several human cells and tissues exposed to specific halogenated and nonhalogenated aromatic chemicals of the "3-methylcholanthrene-type." In laboratory animals AHH induction is known to be regulated by binding of inducers to the Ah receptor, a soluble intracellular protein. However, the induction mechanism in the human species is incompletely understood largely because the Ah receptor, which seems to be essential to the induction process, has not previously been detectable in certain human cells and tissues (including placenta) that are highly responsive to AHH induction. We found that human placenta contains high concentrations of Ah receptor (comparable to the receptor concentrations in rat and mouse liver) but that special modifications were necessary in the assay techniques in order to detect and accurately quantitate receptor binding. Receptor was detected at concentrations approximately equal to 100 fmol/mg cytosol protein using [3H]2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as the radioligand. This high concentration of specific binding sites was present only if the placental tissue was initially homogenized in a buffer containing sodium molybdate (10 or 20 mM). Without molybdate in the homogenizing buffer, specific [3H]TCDD binding was only about 35 fmol/mg. Specific Ah receptor binding also was detectable with [3H]-3-methylcholanthrene and, to a lesser extent, with [3H]-benzo(alpha)pyrene. The receptor sedimented near 9S on sucrose gradients whether molybdate was present or not. About 80% of specific binding was lost if excessive charcoal was used to adsorb "nonspecifically bound" ligand from cytosol prior to gradient analyses. The apparent affinity with which [3H]TCDD bound to Ah receptor in human placental cytosol was relatively low (apparent Kd approximately equal to 5 to 8 nM) when compared with the affinity of [3H]TCDD binding in rat or mouse hepatic cytosols (Kd approximately equal to 1 to 3 nM). These data suggest that while molybdate has very little effect on the quantity or molecular size of the rodent Ah receptor assay, it is very important in stabilizing the human Ah receptor. Our experiments demonstrate that human placenta contains a high concentration of Ah receptor and suggest that AHH induction in placenta is mediated through a receptor mechanism analogous to that previously established in tissues and cells from laboratory animals.

Benzo(a)pyrene↗
PubMed1987

Interposition of the gallbladder--or the absent common hepatic duct and cystic duct.

Interposition of the gallbladder is a rare anomaly, but its diagnosis is important since it represents a surgically correctable cause of jaundice. The patients present with jaundice, abdominal pain and sometimes an enlarged gallbladder. Radiological diagnosis may be difficult since the condition may be mistaken for a choledochal cyst, hydrops of the gallbladder or Caroli's disease. The ultrasound, cholangiogram and surgical findings of dilated intrahepatic ducts adjacent to a normal or enlarged gallbladder with no dilatation of the common bile duct are presented in two children with this condition.

Child, Preschool↗
PubMed1987

Morbidity after percutaneous liver biopsy.

The safety of percutaneous liver biopsy with a 1.2 mm Menghini needle in infants aged one year or less was investigated. One hundred and eighty four procedures performed from 1975 to 1985 were reviewed. There were no deaths or major complications within 48 hours associated with the procedure. In five instances specific complications occurred: a drop in haemoglobin concentration (three), transient hypotension (one), and haematoma at the biopsy site (one). The result of liver biopsy was diagnostic in 83% of cases, compatible with unspecified metabolic disease in 8%, and normal or not diagnostic in 9%. This study suggests that percutaneous liver biopsy can be performed with relative safety in small infants if coagulation is normal and there are no major contraindications, and the results yield important diagnostic information which cannot be obtained using less invasive procedures.

Biopsy, Needle↗
PubMed1986

Induction of drug-metabolizing enzymes: mechanisms and consequences.

The activity of many enzymes that carry out biotransformation of drugs and environmental chemicals can be substantially increased by prior exposure of humans or animals to a wide variety of foreign chemicals. Increased enzyme activity is due to true enzyme induction mediated by increased synthesis of mRNAs which code for specific drug-metabolizing enzymes. Several species of cytochrome P-450 are inducible as are certain conjugating enzymes such as glutathione S-transferases, glucuronosyl transferases, and epoxide hydrolases. Induction of drug-metabolizing enzymes has been shown in several instances to alter the efficacy of some therapeutic agents. Induction of various species of cytochrome P-450 also is known to increase the rate at which potentially toxic reactive metabolic intermediates are formed from drugs or environmental chemicals. Overall, however, induction of drug-metabolizing enzymes appears to be a beneficial adaptive response for organisms living in a "chemically-hostile" world.

Animals↗
PubMed1986

Ah receptor mediating induction of aryl hydrocarbon hydroxylase: detection in human lung by binding of 2,3,7,8-[3H]tetrachlorodibenzo-p-dioxin.

In laboratory animals and in mouse hepatoma cells in culture the Ah receptor previously has been shown to mediate induction of aryl hydrocarbon hydroxylase (cytochrome P1-450) by 3-methylcholanthrene, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. We examined human lung cytosols to determine whether the Ah receptor was present in human tissues. Cytosol was prepared from grossly normal lung tissue obtained at pulmonary lobectomy for presumed lung cancer from 53 consecutive adult patients including 32 males (42-77 years old) and 21 females (18-81 years old). Ah receptor in the cytosols was identified and quantitated by specific binding of [3H]TCDD after separation by ultracentrifugation on sucrose gradients. Specific binding of [3H]TCDD to a component which met the criteria for Ah receptor was detected in 10 of the 53 specimens. As previously established in tissues from laboratory animals, the specific [3H]TCDD-binding component sedimented approximately 9S. Binding of [3H]TCDD to the 9S component was competitively inhibited by incubation in the presence of 2,3,7,8-tetrachlorodibenzofuran, dibenz(a,h)anthracene, and nonradioactive TCDD, all known to be potent agonists for Ah-receptor-mediated induction of aryl hydrocarbon hydroxylase. Specific Ah receptor also was detected in some specimens by direct binding of [3H]-3-methylcholanthrene. The human population studied exhibited striking heterogeneity in Ah receptor concentrations. Only 10 of the 53 individuals studied had detectable Ah receptor. In specimens with detectable specific binding, the mean concentration of binding sites was 6.9 +/- 1.2 (SE) fmol/mg cytosolic protein. These concentrations are approximately 10-30% of the concentrations of Ah receptor found in lung cytosols from laboratory animals. Our experiments indicate that the Ah receptor can be detected in lung cytosol from some humans and suggest that the regulatory mechanism mediating human cytochrome P1-450 induction may be similar to that in the murine model. Aryl hydrocarbon hydroxylase, the major enzyme induced under control of the Ah receptor, plays an important role in the metabolism of several carcinogens including polycyclic aromatic hydrocarbons such as benzo(a)pyrene. It is possible that differences in the Ah receptor content within the human population may be genetically based and that variation at the Ah receptor level may be an important determinant of individual susceptibility to certain chemically induced cancers.

Aryl Hydrocarbon Hydroxylases↗
PubMed1985

Partial nodular transformation of liver in an adult with persistent ductus venosus. Review with hypothesis on pathogenesis.

Partial nodular transformation of the liver (PNT) is a rare condition of unknown pathogenesis in which nodules composed of hepatocytes replace portions of the parenchyma. There is usually evidence of portal hypertension and portal vein thrombosis. We present a case of PNT in a man with persistent ductus venosus and hypoplasia of the major intrahepatic portal veins but without evidence of portal hypertension or portal vein thrombosis. Portal venules were largely absent between nodules, as documented by morphometry. We suggest the pathogenesis of PNT is similar to that previously proposed for nodular regenerative hyperplasia, that is, atrophy occurs in parenchyma with insufficient blood supply and nodules arise by hyperplasia in areas with adequate supply. Partial nodular transformation and nodular regenerative hyperplasia differ mainly in the cause and distribution of the portal vein obliteration.

Adult↗
PubMed1984

Occurrence of alpha-1-antitrypsin deficiency in 155 patients with alcoholic liver disease.

Liver biopsies from 155 patients with alcoholic liver disease were examined for periodic-acid-Schiff-positive, diastase-resistant (PAS-DR) intracytoplasmic globules in hepatocytes. Seven patients had these PAS-DR globules: each was a heterozygote for a deficiency allele of alpha-1-antitrypsin (AAT), or alpha-1-protease inhibitor, with the PAS-DR globules distributed in a pattern characteristic of this deficiency. One further patient with normal AAT had a few intracytoplasmic PAS-DR globules in occasional hepatocytes. The prevalence of AAT heterozygotes in this series did not differ from that in the reference population. The seven heterozygotes included five of PI (protease inhibitor) type MZ, one of PI type SZ, and one heterozygous for a rare deficiency allele, PI type MMmalton. The M and Mmalton alleles may be difficult to distinguish because they have similar mobilities with isoelectric focusing technics. Therefore, if PAS-DR inclusions are found in the liver of a patient with an apparently normal phenotype, the presence of a defective M variant allele, such as Mmalton, should be considered.

Adult↗
PubMed1979

Ampicillin concentrations in pancreatic fluid bile obtained at endoscopic retrograde cholangiopancreatography (ERCP).

To investigate the distribution of ampicillin to the pancreas, ampicillin concentrations in pancreatic fluid obtained at endoscopic retrograde cholangiopancreatography (ERCP) were determined. Alternatively, ampicillin concentrations in bile obtained via ERCP were determined. Ten subjects with non-acute biliary-tract or pancreatic disease received a single dose of ampicillin (250 or 500 mg) parentally before ERCP. Timed simultaneous specimens of blood and pancreatic fluid or bile were obtained. Serum concentrations of ampicillin were measured in all subjects. In six of seven subjects no ampicillin was detectable in pancreatic fluid; in the seventh less than 1 microgram/ml was found. Pancreatic duct anatomy did not appear to correlate with pancreatic fluid concentrations. Failure to detect ampicillin in pancreatic fluid may account for results of clinical studies in which no clinical benefit from ampicillin has been found. Low or undetectable concentrations of ampicillin were found in bile; these concentrations in bile obtained at ERCP are similar to those found previously in bile recovered at biliary-tract surgery.

Adult↗
PubMed1976

Massive bleeding from a ruptured superior mesenteric artery aneurysm duodenum.

A traumatic false aneurysm of the superior mesenteric artery resulting from a gunshot wound five years previously, caused massive hemorrhage into the second portion of the duodenum. Dissection, resection, and end-to-end anastomosis was successful in controlling bleeding into the gastrointestinal tract, but immediate postoperative angiography showed a reappearance of the aneurysm, and three months later, it bled into the retroperitoneum. The patient underwent further resection and two subsequent reconstructions of the superior mesenteric artery, the first with a Dacron graft, which clotted, and the second with autologous saphenous vein, which was successful. Three years later, the patient is well. The case shows that adequate reconstruction of an arterial injury is best performed immediately after it is diagnosed.

Abdominal Injuries↗
PubMed1974

Subphrenic abscess: comparison between operative and antibiotic management.

Subphrenic abscess is still a significant hazard which complicates surgical procedures as well as certain abdominal catastrophes. This is a report of 88 patients with subphrenic abscess at St. Vincent's Hospital and Medical Center of New York from 1954 through 1971. There were 46 males and 42 females, ranging from 2 to 88 years. Operations on the stomach, duodenum and biliary tract were the major causes. The causative organisms in order of frequency were: E coli (41.6%), Staphylococcus (41.6%), Aerobacter aerogenes (23.3%), Proteus (20%), Streptococci (18.3%) and Pseudomonas (8.3%). Penicillin and tetracycline, the antibiotics most commonly chosen on an empiric basis, proved effective in only 38% of cases. On the other hand, kanamycin, chloramphenicol and cephalothin were effective in 90%, 85% and 70% of cases respectively. The overall mortality rate was 15%. Nine of the 21 patients (42.8%) treated with antibiotics alone died while 11 of 67 patients (10.6%) treated with antibiotics and surgical drainage died. Some of the latter deaths occurred in patients treated with prolonged antibiotic therapy and operated on only as a last resort. In this series subphrenic abscess was best treated by early surgical drainage combined with the use of appropriate antibiotics.

Abdominal Injuries↗