Flow cytometry and Barrett's esophagus.
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Adenocarcinoma↗
Biomedical subjects
E Kahn
Publications and source records attributed to E Kahn.
The appendix in inflammatory bowel disease in children.
The morphologic characteristics of the colon in ulcerative colitis and Crohn's disease are well established, but specific appendiceal pathology is less clearly defined. In addition, the frequency of appendiceal involvement in children with inflammatory bowel disease has also not been delineated. We have determined the prevalence of appendiceal involvement in 41 children with inflammatory bowel disease (24 with Crohn's disease and 17 with ulcerative colitis) who required colonic resection and have defined the histopathologic characteristics of the appendix in these diseases. All appendices were abnormal. Specific changes of Crohn's disease or ulcerative colitis were observed respectively in 50% and 56% of the appendices in our patient population. Nonspecific changes only such as fibrous obliteration, serosal fibrosis and lymphoid and/or neuronal hyperplasia were noted in the remaining appendices. The severity of ileocolonic and appendiceal inflammation was similar in about two thirds of the patients with either type of inflammatory bowel disease.
Adolescent↗
Bradykinin-induced oscillations of cell membrane potential in cells expressing the Ha-ras oncogene.
Products of ras genes are putative elements of growth factor signal transduction. However, the mechanism of action of these proteins in normal and malignant growth is as yet obscure. To test for functional consequences of ras oncogene expression, electrophysiological experiments were performed on NIH-3T3 fibroblasts transfected with a transforming Ha-ras MMTV-LTR construct expressing the oncogene on treatment with dexamethasone (+ras). Transfected cells in the absence of dexamethasone (-ras) and nontransfected cells in the presence of dexamethasone (oras) served as controls. In -ras and oras, bradykinin induces a single, transient hyperpolarization. In +ras, bradykinin elicits oscillations of cell membrane potential throughout the presence of the hormone by activation of calcium-sensitive K+ channels. The oscillations of cell membrane potential are abolished in the absence of extracellular calcium. As evident from fura 2 fluorescence, bradykinin leads to a transient increase of intracellular calcium both in the presence and absence of extracellular calcium. Oscillations of intracellular calcium could be observed in +ras cells, if bradykinin was applied at reduced extracellular sodium concentration possibly to impair calcium extrusion via the sodium/calcium exchange. Bradykinin induces oscillations of cell membrane potential similarly in -ras cells loaded with GTP[S], a nonhydrolyzable analogue of GTP. Thus, the altered response of ras oncogene expressing cells to bradykinin relates to the GTP binding property of the ras protein. It is concluded that in cells expressing ras oncogene but not in other fibroblasts bradykinin mimicks the effect of growth factors on the cell membrane.
Bradykinin↗
Hepatic pathology in pediatric acquired immunodeficiency syndrome.
In a retrospective study we assessed the hepatic changes in children with the acquired immunodeficiency syndrome by reviewing 12 biopsy specimens and 48 autopsy specimens from 54 children. Hepatopathology differed in biopsy and autopsy material. In biopsy specimens, chronic active hepatitis with predominantly T8 lymphocytes by tissue immunochemistry was common (five of 12 specimens). Fatty degeneration and hepatocellular necrosis were either absent, mild, or patchy. On the other hand, at autopsy, chronic active hepatitis was not observed. The most prominent changes were extensive fatty degeneration, nonspecific portal mononuclear infiltration, portal fibrosis, and confluent (ischemic) necrosis. Opportunistic infections such as Mycobacterium avium-intracellulare (MAI) were noted only at autopsy. In addition, three unusual morphologic characteristics were noted: nodular lymphoplasmacytic portal infiltrate, a pseudosarcomatous variant of Mycobacterium avium-intracellulare infection, and multinucleated giant cells (foreign both type and giant cell transformation of hepatocytes).
Acquired Immunodeficiency Syndrome↗
Erosion through the posterior gastric wall by a pancreatic pseudocyst secondary to gastric duplication.
Gastric duplications are the rarest form of enteric duplication. They account for about 20% of all gastrointestinal duplications. Delayed and missed diagnosis leads to prolonged morbidity and mortality. We report a case of a child with a gastric duplication cyst in the body of the pancreas, associated with a pancreatic pseudocyst that ultimately eroded into the posterior wall of the stomach.
Humans↗
Image registration and distortion correction in ion microscopy.
We present a method whereby the geometric registration of a series of ion microscopic images is performed by applying a two-step procedure. After applying a global linear transformation that corrects for geometric differences, a non-linear elastic transform is used in order to match local properties and structures of the images. Transformation parameters are computed on the basis of shape-specific points in the images. Distortion correction is achieved by relating ion images to the optical image of the same field and by using the two-step algorithm to register the images. This methodology is evaluated on synthetic misaligned objects and on thyroid tissue images.
Animals↗
[Functional microscopic imaging of the thyroid gland with the help of analytical ion microscopy].
Secondary ion mass spectrometry (SIMS) microscopy provides a direct mapping of 127I in thyroid follicles. Thyroid tissue should be fixed and embedded in methacrylate resin, then cut in 3 microns-thick sections which are placed on a gold coverslip. The histological structure of the tissue is determined by the phosphorus ion (31P) which is present in large amounts in nuclei and phosphorylated molecules in the cytoplasm. An image processing system is used to superimpose images of 127I and 31P: this system allows measurement of local concentration of 127I in the follicular cell and follicular lumen compartments. A study in 8 subjects with normal thyroid glands showed that the level of 127I within follicular cells (430 +/- 250 micrograms/g; m +/- SE) was 6 to 7 times lower than the level in the follicular lumen (2.780 +/- 230 micrograms/g). In simple goiter (9 patients with macrofollicular adenomas), follicular lumen (346 +/- 17 micrograms/g) and cellular (68 +/- 6 micrograms/g) concentrations of 127I were decreased fivefold but the ratio of concentrations remained similar to that seen in normal tissue. In hyperfunctioning nodules (2 microfollicular and 3 macrofollicular adenomas), follicular cell and follicular lumen 127I levels varied widely and showed considerable overlap (2 to 16,000 micrograms/g and 1-21,000 micrograms/g, respectively). In benign cold nodules (1 microfollicular adenoma and 2 macrofollicular adenomas), follicular cell and follicular lumen 127I levels were barely detectable (3 +/- 0.6 micrograms/g and 6 +/- 0.7 micrograms/g respectively). In the 9 malignant nodules studied, no difference in 127I level profile was found with benign nodules.(ABSTRACT TRUNCATED AT 250 WORDS)
Goiter, Nodular↗
Paucity of interlobular bile ducts. Arteriohepatic dysplasia and nonsyndromic duct paucity.
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Biliary Atresia↗
Neuronal intestinal dysplasia: quantitative diagnostic criteria and clinical management.
Neuronal intestinal dysplasia (NID) clinically resembles Hirschsprung's disease but is characterized by hyperplasia rather than aganglionosis of the intramural plexus. Surgical intervention is common. We report the 5-year follow-up of an infant with the mixed form of NID managed medically and a method by which NID can be quantified histologically. Hyperganglionosis was determined by counting the number of ganglia per high-power field and the number of ganglion cells per ganglia from at least two biopsy specimens. The patient's biopsies and biopsies from "normal" and "inflamed" patients were compared. Normals contained 0.68 +/- 0.28 (mean +/- SD) ganglia per high-power field and 2.16 +/- 0.31 ganglion cells per ganglion. The inflamed biopsies were similar, 0.69 +/- 0.38 ganglia per high-power field and 2.63 +/- 0.40 ganglion cells per ganglion. The patient's initial rectal biopsy revealed 7.6 ganglia per high-power field and 3.8 ganglion cells per ganglion. Management of the patient included saline colonic irrigations and hyperalimentation with gradual reinstitution of breast-feeding. Clinical improvement was associated with normalization of manometry and biopsy findings, a phenomenon not documented previously in the literature. Irrigations were stopped at age 9 months, and the child is now asymptomatic.
Biopsy↗
Lung scintigraphy clustering by texture analysis.
The efficiency of texture analysis parameters, describing the organization of grey level variations of an image, was studied for lung scintigraphic data classification. Twenty one patients received a 99mTc-MAA perfusion scan and 81mKr and 127Xe ventilation scans. Scans were scaled to 64 grey levels and 100 k events for inter subject comparison. The texture index was the average of the absolute difference between a pixel and its neighbors. Energy, entropy, correlation, local homogeneity and inertia were computed using co-occurrence matrices. A principal component analysis was carried out on each parameter for each type of scan and the first principal components were selected as clustering indices. Validation was achieved by simulating 2 series of 20 increasingly heterogeneous perfusion and ventilation scans. For most of the texture parameters, one principal component could summarize the patients data since it corresponded to the relative variances of 67%-88% for perfusion scans, 53%-99% for 81mKr scans and 38%-97% for 127Xe scans. The simulated series demonstrated a linear relationship between the heterogeneity and the first principal component for texture index, energy, entropy and inertia. This was not the case for correlation and local homogeneity. We conclude that heterogeneity of lung scans may be quantified by texture analysis. The texture index is the easiest to compute and provides the most efficient results for clinical purpose.
Humans↗
Idiopathic arterial calcification of infancy: a case with prolonged survival.
We describe a patient with idiopathic arterial calcification of infancy and the following unusual features of the disease: (1) prolonged survival until age 11 years, (2) discordance between the extent of vascular calcification and clinical manifestations of arterial luminal occlusion, (3) a large area of myocardial calcification, (4) symptoms of cerebral-vascular insufficiency, and (5) spontaneous resolution of hypertension.
Calcinosis↗
Clinical ecology: environmental medicine or unsubstantiated theory?
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Ecology↗
A crisis of community anxiety and mistrust: the Medfly eradication project in Santa Clara County, California, 1981-82.
Public anxiety of near panic proportions was created by the announcement of a plan to commence aerial application of malathion bait over a large urban area in California for the eradication of the Mediterranean fruit fly within four days. A risk assessment had reported the project entailed no significant risk to health but environmentalist groups and the media ignored the report. We describe the successful measures taken by State health workers to counteract the anxiety which itself constituted a serious public health problem. The most important measure was the rapid convening of a Health Advisory Committee composed of recognized experts and local professionals and leaders to provide an authoritative, respected and sympathetic voice to deal with the community's concerns. These experiences may be of value to other communities facing unwarranted anxiety over perceived environmental hazards.
Animals↗
Digital correlation of ion and optical microscopic images: application to the study of thyroglobulin chemical modification.
A method has been developed in order to digitally correlate ion and optical microscopic images of the same sample areas. Serial cross-sections of human thyroid tissue were analyzed by secondary ion mass microscopy and by light microscopy. The resulting chemical and immunochemical map images were superimposed and correlated by means of a two-pass registration algorithm which allows to correct for geometrical distortions introduced by the ion microscope. Results are presented for the study of thyroglobulin chemical modification in pathological thyroid tissue that demonstrates heterogeneous molecular activity.
Humans↗
Clinical ecology: environmental medicine or unsubstantiated theory?
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Environmental Exposure↗
Cholinesterase activity depression among California agricultural pesticide applicators.
Cholinesterase activity measurements for 542 California agricultural pesticide applicators under medical supervision during the first 9 months of 1985 were analyzed. Twenty-six workers, 4.8% of the sample, had cholinesterase values at or below the California threshold values for removal from continued exposure to cholinesterase-inhibiting pesticides (60% of baseline for red blood cell cholinesterase and 50% of baseline for plasma cholinesterase activity). Eight of these 26 workers, 31.5%, had pesticide-related illnesses. Pesticides most frequently associated with cholinesterase depressions exceeding California threshold values included mevinphos (Phosdrin), oxydemeton methyl (Metasystox-R), methomyl (Lannate), and acephate (Orthene); these pesticides included organophosphates in toxicity categories I and II and one carbamate in toxicity category I.
Agricultural Workers' Diseases↗
Human ontogeny of the bile duct to portal space ratio.
Paucity of interlobular bile ducts is a common feature of cholestatic liver disease in premature infants. Whereas a bile duct to portal space ratio of 0.9 to 1.8 is cited by Alagille as the norm for children, there are no data regarding the normal bile duct to portal space ratio in preterm infants. In this study, by examining liver tissue obtained from autopsied fetuses and infants, we have determined that the bile duct to portal space ratio increases as a function of postconceptional age. After 38 weeks postconception, a ratio equal to or greater than 0.9 was seen in eight of nine subjects. Therefore, in evaluating premature infants for duct paucity, liver biopsies should be obtained only after 38 weeks. Prior to 38 weeks postconception, a bile duct to portal space ratio less than 0.9 may be physiologic.
Bile Ducts, Intrahepatic↗
Epidermoid splenic cyst detected on a sports physical examination.
A 14-year-old female had a large, nontender abdominal mass on a routine sports physical examination. Following evaluation by ultrasound and computed tomography scan there was an initial attempt at drainage. The mass was subsequently removed. The diagnosis was epidermoid cyst of the spleen. In this report, we discuss the epidemiology and management of a splenic cyst, a rarely encountered diagnosis in adolescents, and emphasize the life-saving potential of the abdominal examination in sports medicine.
Adolescent↗