Hyperlipidemic gestational pancreatitis.
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Blood Component Removal↗
Biomedical subjects
I M Roberts
Publications and source records attributed to I M Roberts.
Signal for potyvirus-dependent aphid transmission of potato aucuba mosaic virus and the effect of its transfer to potato virus X.
A British isolate of potato aucuba mosaic potexvirus (PAMV) was transmitted by aphids (Myzus persicae) which had fed previously on a source of potato Y potyvirus (PVY). Nucleotide sequence analysis of the PAMV coat protein gene indicated that amino acid residues 14 to 16 from the N terminus of the coat protein have the sequence DAG, which is also found in the coat proteins of potyviruses and is required for their aphid transmissibility. A recombinant virus isolate (TXPA7) was produced in which a segment of the coat protein gene of PAMV encoding the 40 N-terminal amino acids was inserted in the genome of potato X potexvirus (PVX) in place of the segment encoding the 28 N-terminal amino acids of PVX coat protein. This isolate, and a second similar recombinant (TXPA5) in which the DAG motif was changed to YTS, were mechanically transmissible to intact plants, in which they caused slightly milder symptoms than PVX. Particles of TXPA7 reacted in immunosorbent electron microscopy with PVX- and PAMV-specific antibodies and so were antigenically distinguishable from PAMV and PVX particles, which reacted only with their homologous antibody, and from TXPA5 particles, which reacted only with the PVX antibody. Recombinant TXPA7 was transmitted by aphids that had already fed on a source of PVY whereas TXPA5 and PVX were not. TXPA7 was not transmitted by aphids that had not fed on a PVY source. It is concluded that (i) the potyvirus-dependent aphid transmissibility of PAMV results from possession of a domain which includes the DAG motif and is located near the N terminus of the virus coat protein, and (ii) potyvirus-dependent aphid transmissibility can be conferred on PVX, a non-aphid-borne potexvirus, by substituting this domain for the N-terminal part of its coat protein.
Amino Acid Sequence↗
Diffraction studies of the particles of two closteroviruses: heracleum latent virus and heracleum virus 6.
X-ray diffraction from oriented specimens of purified preparations of particles of heracleum latent closterovirus (HLV) showed that they have a helical arrangement of protein subunits, and that the structure repeats in five helical turns in which there are 5q +/- 1 protein subunits, where q is an integer. The pitch of the helix was estimated to be 3.26 (+/- 0.10) nm. Optical diffraction patterns from electron micrographs of HLV particles give an estimated pitch of 3.3 (+/- 0.2) nm and show that the number of subunits in the repeat period is 5q-1, where q has a value of 8 or 9. Optical diffraction from electron micrographs of particles of a second closterovirus, heracleum virus 6, shows that they too have a helical structure which repeats in five turns, in which there are 5q +/- 1 protein subunits. The estimated pitch of the primary helix is 3.6 (+/- 0.2) nm, and the estimate of q is 9.
Microscopy, Electron↗
PC GI board review. A ToolBook application for postgraduate review of Gastroenterology.
"Hypertext" applications have become an important educational resource for medical teaching. ToolBook version 1.5 allows the import of SVGA 256 color, 640 x 480 pixel images. We developed a program for the review of Gastroenterology by Subspecialty Board applicants which included digitized pathology, endoscopy, dermatology, and radiology images interfaced with textual description. 5 cases were presented with 6 questions per case to test the user's comprehension of the material. A scoring function was included to give feedback to the users. An evaluation questionnaire was also completed to survey user satisfaction with the program. A similar "shell" could be applied to other teaching programs.
Computer-Assisted Instruction↗
A comparison of the sensitivity and specificity of enzyme immunoassays and time-resolved fluoroimmunoassay.
Time-resolved fluoroimmunoassay (TR-FIA) and various enzyme immunoassays (EIA) were compared in order to determine the detection system which showed the greatest degree of sensitivity without sacrificing specificity. The system chosen for the evaluation of these assays was the detection of antibodies to human immunodeficiency virus (HIV). For EIA, horseradish peroxidase (HRP) and alkaline phosphatase (AP) were investigated, each with a number of different substrates. HRP with its fluorogenic substrate, 3-(p-hydroxyphenyl)propionic acid (HPPA) was 1.6 times (p less than 0.01) more sensitive than with 3,3',5,5'-tetramethylbenzidine (TMB) and four times (p less than 0.001) more sensitive than with 2,2'-azino-di(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS). AP with its fluorogenic substrate, 4-methylumbelliferyl phosphate (4MeUP), was 6-7 times (p less than 0.001) more sensitive than with phenolphthalein monophosphate (PMP) and 8-13 times (p less than 0.001) more sensitive than with p-nitrophenyl phosphate (pNPP). TR-FIA with Eu3(+)-labelled anti-human IgG was equivalent in sensitivity to HRP with TMB and AP with 4MeUP.
Acquired Immunodeficiency Syndrome↗
Neuromodulators of the lingual von Ebner gland: an immunocytochemical study.
The serous lingual glands of von Ebner secrete lingual lipase, an enzyme that begins fat digestion in the stomach. The objective of this study was to characterize the neuromodulators in the rat tongue and von Ebner glands using immunocytochemical techniques. Rat lingual tissues were fixed in formalin, embedded in paraffin and sectioned at 4 microns for light microscopic studies. Immunocytochemical localization of neuromodulators was performed with monospecific anti-rat neuromodulator IgG or control (preimmune) IgG as the primary antibody, using the peroxidase-antiperoxidase (PAP) technique. No staining was seen with control anti-rat IgG. Immunospecific staining for vasoactive intestinal peptide (VIP), tyrosine hydroxylase and choline acetyltransferase (CHAT) was observed in nerves in the tongue, and cells containing immunospecific staining for serotonin (5-hydroxytryptamine) were seen in the stroma between the lingual glands. Selected cells in the serous glands stained positively for the presence of substance P and somatostatin. Adrenergic, VIP-containing and cholinergic nerves appear to innervate the tongue and serous glands. Substance P and somatostatin were identified in cells of the lingual serous glands and may be additional local modulators regulating lingual lipase release.
Animals↗
Esophageal obstruction after ingestion of a fiber-containing diet pill.
Foreign bodies of the esophagus in adults may be the result of a food bolus that becomes lodged proximal to a structural abnormality of the distal esophagus. A case of peptic stricture of the esophagus in a patient who presented with acute dysphagia after ingesting an over-the-counter diet pill composed of guar gum is discussed. It is recommended that anorectics composed of dietary fiber should not be used in patients with a history of esophageal stricture.
Aged↗
Production of a cytotoxic human monoclonal antibody with specificity for HLA-DR4 and -DRw10 by cells derived from a highly sensitized kidney recipient.
A human monoclonal antibody which reacts preferentially with HLA-DR4 and -DRw10 B-cell targets has been produced. A human B-cell line, secreting antibody which reacted preferentially with DR4 and DR1 targets, was derived from a highly sensitized kidney recipient who had rejected two grafts. This line was fused with the mouse myeloma P3X63Ag8.653 and a selected hybridoma cloned. The clones secrete IgM(lambda), which reacts strongly with HLA-DR4 and -DRw10 and more weakly with -DRw14 and a proportion of -DR1 B cells in cytotoxicity assays. Using B-cell lines as targets in cytotoxicity and enzyme-linked immunosorbent assays, the antibody gives a broader pattern of reaction, reacting with HLA-DR1, -DR4, -DR9, -DRw10, -DRw14, and some -DR2 targets. The antibody (NI) is currently in use as a reagent for tissue typing.
Animals↗
Atypical eating disorder masquerading as recurrent acute pancreatitis: the value of multiple pancreatic serological markers.
A 28-year-old woman with nausea, vomiting, and abdominal pain had been hospitalized elsewhere on 13 separate occasions over the year before this admission for similar episodes thought to be secondary to acute pancreatitis. She had undergone repeated work-ups including endoscopic retrograde cholangiopancreatography, computed tomographic scan, and exploratory laparotomy. There was a discrepancy between her unremarkable physical examination and extremely elevated amylase (3,210 U/L) which suggested nonpancreatic hyperamylasemia; normal serum pancreatic isoamylase, trypsinogen, and lipase confirmed this suspicion. The patient was noted to have self-induced vomiting in the hospital which she admitted was frequent behavior. her psychiatric disturbance was characterized as an atypical eating disorder. This case illustrates that hyperamylasemia in association with abdominal pain, nausea, and vomiting may not be secondary to pancreatitis and that use of a second serum marker (such as trypsinogen, lipase, or isoamylase) helps to establish a definitive diagnosis.
Acute Disease↗
Disorders of the pancreas in children.
Diseases of the pancreas in children are often congenital; the genetic basis of some conditions such as cystic fibrosis have been elucidated using molecular biologic techniques. Anatomic abnormalities in childhood that cause symptomatic pancreatic disease are usually treated surgically. The biochemical abnormalities found with enzyme deficiencies, CF, and Shwachman's syndrome are best treated with medical therapy. The most common cause of acute pancreatic injury in children is trauma. Chronic pancreatic insufficiency usually occurs secondary to CF.
Acute Disease↗
Secondary structures of rat lipolytic enzymes: circular dichroism studies and relation to hydrophobic moments.
To explore the secondary structures of lingual and pancreatic lipases, circular dichroism measurements were performed. Maximum average ellipticities were used to calculate the percentage of alpha-helices, beta-sheets, and random coils. Lingual lipase had an ellipticity of -20235 +/- 140 deg cm2/dmol (mean +/- SE) at 220 nm suggesting 60% alpha-helix, 20% beta-sheet and 20% random coil structure, but the mean ellipticity for pancreatic lipase was -14093 +/- 82 deg cm2/dmol (mean +/- SE) at 210 nm suggesting a 34.8% alpha-helical, 25% beta-sheet and 40% random coil secondary structure. An alpha-helical stretch of residues with a large hydrophobic moment ("globular" alpha-helix by hydrophobic moment plot) from amino acids 382 through 389 at the COOH-terminal end of lingual lipase was noted. This sequence, absent in pancreatic lipase, may account for the avid binding of lingual lipase to fat emulsion particles.
Amino Acid Sequence↗
Fecal lipid excretion in pancreatic insufficiency.
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Exocrine Pancreatic Insufficiency↗
Enzyme therapy for malabsorption in exocrine pancreatic insufficiency.
Fat malabsorption in patients with chronic alcoholic pancreatitis and cystic fibrosis may lead to vitamin and essential fatty acid deficiency in addition to steatorrhea. In clinical practice it can be difficult to achieve complete correction of malabsorption and elimination of steatorrhea. The earliest treatment methods used the oral administration of porcine pancreatic enzyme preparations. These conventional enzymes, however, were unstable in the acidic intragastric environment. Subsequently, medications to neutralize or reduce gastric acidity (H2-blockers, antacids, or bicarbonate) were added to improve the stability of the conventional enzymes. Enteric-coated enzyme preparations were then developed that would release only in an alkaline milieu, protecting the enzymes from acid denaturation. The newest and potentially most exciting modalities for the treatment of fat malabsorption are acid-stable lipases, obtained either from a fungal source or through the expression of cloned genes for the enzymes utilizing recombinant DNA techniques. The advantages and disadvantages of the various medications for the therapy of fat malabsorption in pancreatic insufficiency are reviewed.
Dietary Fats↗
Indian cassava mosaic virus: ultrastructure of infected cells.
Ultrastructural examination of leaf tissue of Nicotiana benthamiana infected with Indian cassava mosaic virus (ICMV) revealed abnormalities in phloem and, occasionally, xylem cells. Nuclei contained granular inclusion bodies which seemed to be largely composed of virus-like particles and were shown by immunogold labelling (IGL) to be rich in ICMV coat protein. Later in infection, hollow spheres made up of fibrillar material were produced. Virus coat protein was not a necessary component of these structures but was sometimes found in their hollow centres. Cytoplasmic abnormalities were uncommon but a few vascular parenchyma cells contained paracrystalline aggregates which seemed to be made up of hollow tubes 30 to 40 nm in diameter. Some of these same cells also had large areas of cytoplasm which contained numerous randomly orientated tubules about 20 nm in diameter. No ICMV coat protein could be detected by IGL in either the paracrystalline or the tubule-containing inclusions. The ultrastructural effects of ICMV resemble those of other whitefly-transmitted geminiviruses, but with some differences of detail, and they also include types of abnormality not previously recorded.
Cell Nucleus↗
Stability of lingual lipase in vivo: studies of the iodinated enzyme in the rat stomach and duodenum.
In order to examine the stability of purified lingual lipase (EC 3.1.1.3) in vivo under fasted and fed conditions, we iodinated rat lingual lipase to a specific activity of 5-10 microCi/micrograms protein with 125I-labelled Bolton-Hunter reagent. Labelled lingual lipase in either saline or Intralipid was administered via an intragastric or intraduodenal cannula. Control labelled lipase preparations were incubated at 37 degrees C. Serial aliquots of gastric or intestinal contents were aspirated and subjected to SDS-polyacrylamide gel electrophoresis followed by autoradiography, and quantitated by densitometric scanning. In all experiments, the amount of lingual lipase in both stomach and duodenum was significantly reduced (P less than 0.05 vs. controls) at 15 and 60 min after administration. In either the presence or absence of Intralipid, lingual lipase was more stable in the stomach than in the duodenum (P less than 0.05). In conclusion, lingual lipase was more stable in the stomach than in the duodenum, and lipid emulsion did not appreciably affect the stability of the enzyme in either location of the upper digestive tract of the rat.
Animals↗
Comparative densities of Wuchereria bancrofti microfilaria in paired samples of capillary and venous blood.
Concurrent finger-prick and venous blood samples were obtained from 43 patients infected with Wuchereria bancrofti. Microfilariae were counted in blood smears and on nuclepore filters. Based on the numbers of microfilariae in 20-microliters finger-prick samples, an expected (theoretical) number of microfilariae in venous samples was calculated. This expected value was compared to the actual number of microfilariae present in venous blood. The actual number of microfilariae present ranged from 0.7 to 30 times (median 3) less than expected. The exponential function y = 16.74e.17x, r2 = .69, where y = venous counts and x = capillary counts was found to accurately reflect the relationship between venous and capillary counts. Each unit (microfilaria) change in capillary blood would result in an expected 19% unit increase/decrease in venous blood. The results support strongly the theory that microfilariae are unevenly distributed in the blood system. The epidemiological implication is that persons with low or ultralow microfilaremia levels in venous blood may have a much greater pool of microfilaria available in capillaries. We believe that the present study explains, at least partially, why mosquitoes feeding on these kinds of microfilaria carriers (frequently) have a greater uptake fo microfilariae than expected.
Adolescent↗
Fecal fat concentrations and pancreatic steatorrhea.
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Celiac Disease↗
Workup of the patient with malabsorption.
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Biopsy↗