Relationship of human pancreatic cholesterol esterase gene structure with lipid phenotypes.

Pancreatic cholesterol esterase is one of the enzymes that plays a pivotal role in cholesterol absorption. Differences in the genotype of this enzyme could affect the susceptibility of individuals to dyslipidemia and/or cardiovascular disease. We undertook this study to investigate if any correlation exists between restriction fragment length polymorphism in the human pancreatic cholesterol esterase gene and serum lipid levels. DNA from 96 healthy adults was restricted with Stu I, Southern blotted, and probed with cDNA of human pancreatic cholesterol esterase. Results revealed six distinct patterns which were classified as A, B, C, D, E, and F which had a population frequency of 1%, 34.5%, 49%, 12.5%, 1% and 2% respectively. Correlation of the distribution of lipid and lipoprotein levels by pattern and sex revealed a significant interaction between pattern type and HDL (p=0.03) in the most common group (group C) for males. Male patients of pattern C tended to have a lower LDL cholesterol than non-pattern C males (p=0.07); in addition, 80% of all males in the study population with LDL cholesterol under 100 mg/dl were found in pattern C. Thus, the most common Stu I RFLP genotype is associated with a favorable lipid phenotype. This report shows an association between the human pancreatic cholesterol esterase genotype and serum lipid levels. Further analysis of a larger study group with Stu I and alternative polymorphic restriction enzymes is warranted, to confirm this biologically plausible result.

Pulmonary artery aneurysm: review and case report.

Aneurysms involving the main pulmonary artery and its branches are rare. Clinical experience is limited and current knowledge is mainly derived from autopsy findings. This case report describes a patient with a pulmonary artery aneurysm associated with a previous, partially corrected stenotic pulmonary valve. The patient presented with symptoms suggestive of aneurysm dissection three decades after commissurotomy. The diagnostic approach and therapeutic intervention are emphasized with a review of the literature.

Cloning and characterization of rabbit pancreatic colipase.

1. Among the digestive enzymes synthesized by pancreas, lipase is the principle lipolytic enzyme which hydrolyses dietary glycerides. 2. For its action it requires a coenzyme, colipase. 3. The molecular mechanisms of the interaction of these two are not fully understood. 4. Further, molecular events that regulate and influence lipid absorption are ill defined. 5. The rabbit is the conventional animal model for the study of lipid absorption. We have undertaken the molecular cloning, and characterization of rabbit pancreatic colipase, the coenzyme for pancreatic lipase. 6. Colipase has been cloned from a gt 11 library of an adult rabbit pancreatic cDNA by probing with an oligonucleotide derived from human colipase sequence. 7. The total reading frame consists of 321 nucleotides coding for 90 amino acids of the functional protein and 17 nucleotides of the leader peptide. 8. Northern blot analysis revealed a distinct band around 0.5 kb. Comparison with other species revealed an over all homology of 75% at the nucleotide level. 9. At the amino acid level highest conservation is observed at the lipase-binding region (AA 53-73). 10. Rabbit enzyme also retained the N-terminal pentapeptide of its preform. 11. The regions of homology and conservation may aid to define the sites of interaction of colipase with lipase.

Molecular cloning and expression of rabbit pancreatic cholesterol esterase.

Rabbit pancreatic cholesterol esterase (CEase, carboxyl ester lipase, EC 3.1.1.3) has been cloned from a lambda gt11 library of adult rabbit pancreatic cDNA. The open reading frame consists of 1788 nucleotides which encodes 576 amino acids of the functional protein and a 20 amino acid leader peptide. When compared to other species, the greatest homology is observed between residues 82-248 with little or no homology at the C-terminal end where proline-glutamate-serine-threonine (PEST) segments are a characteristic feature of the human CEase. Rabbit CEase (RCEase) retains the active-site serine (gxsxg), the active-site histidine and the tentative heparin binding site (KKRCLQ) at similar positions in comparison to pancreatic CEases of other species. When rabbit CEase cDNA is expressed in monkey kidney (COS-7) cells, enzymatic hydrolytic activity is detected in the growth medium as is a 67 kDa protein by Western blotting with polyclonal anti-CEase antibody. Northern blot analysis shows two mRNA (2.2 and 3.2 kb) species.

Molecular cloning and characterization of rabbit pancreatic triglyceride lipase.

Pancreatic lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) has been cloned from a gt11 cDNA library made from poly A+ RNA of adult rabbit pancreas. Pancreatic lipase (PL) assists the absorption of dietary triglycerides by hydrolyzing them at 1 and 3 positions to free fatty acids and 2-monoacylglycerol in the presence of bile acids and colipase in the intestinal lumen. Since rabbits are classifically used for the study of the diet induced changes in the lipid metabolism, as a prelude to studying the diet and age dependent changes in the expression of this enzyme, a full length PL cDNA clone was obtained from its pancreas. The coding region of rabbit pancreatic lipase cDNA consists of 1407 base pairs contained in an open reading frame encoding 469 amino acids including the 16 that constitute the signal peptide. Northern blot analysis revealed a band around 1.5 kb. When rabbit enzyme is compared to other species, an over all homology of 70-80% was observed at the nucleotide level. High homology in the amino acid sequence and composition is also apparent between rabbit and other species like dog (65%), pig (76%) and rat (63%). Highest homology is found to be around active-site serine. The regions of homology with other species may help to define sites of interaction of lipase with co-lipase.

Structure of the human pancreatic cholesterol esterase gene.

The gene for human pancreatic cholesterol esterase consists of 11 exons and 10 introns and is 9.2 kb in length. The last and longest exon (841 nucleotides) is unique to the human gene. Functional amino acids are encoded on separate exons. The leader sequence is encoded by a single exon which carries two additional N-terminal amino acids of the mature functional protein. A positive TATA element is identified 43 nucleotides from the start codon. Pulse-field gel electrophoresis and hybridization with various cDNA probes and direct sequence data revealed the existence of a CEase-like gene. Partial sequence analysis of this gene from a human cosmid library and human genomic DNA showed a premature stop signal in exon 10, shortly after the codon for the active-site histidine. Both the functional gene and the CEase-like gene have a polyadenylation signal in the 3'-untranslated region. Thus, the complex gene structure for this intestinally active enzyme may provide in part a potential molecular explanation for the well-known heterogeneity of the intestinal absorption of cholesterol.

Usefulness of single fibrinopeptide A determination in patients with acute ischemic coronary artery syndromes.

Coronary artery thrombosis plays a major role in the acute ischemic coronary artery syndromes in which fibrinopeptide A (FPA) has proved to be a sensitive marker. The purpose of this study was to determine FPA concentrations in patients with acute coronary artery syndromes and to determine if these could serve as a short-term prognostic indicator. Single plasma FPA levels were measured in 26 patients with acute ischemic coronary artery syndromes within 24 hours of the onset of chest pain as well as in 12 patients with chronic stable angina and in 9 control subjects. Higher FPA levels were observed in patients with unstable angina whom later developed recurrence of chest pain compared to those without (8.1 +/- 3.4 vs. 3.4 +/- 2.2; p = 0.01). Neither the localization of ischemia, presence of complications, need for revascularization nor short-term prognosis (6 months) correlated with the plasma FPA concentration. Therefore, except for recurrence of chest pain in patients with unstable angina, the finding of an elevated FPA level upon admission did not provide additional information regarding clinical course and prognosis than that obtained in a detailed clinical history, physical examination and initial electrocardiogram in patients with acute ischemic artery syndromes.

Neural transplants: volumetric analysis of their growth and histopathological changes.

Neocortical transplants from 15-, 18- and 22-day rat embryos were transplanted into the cerebellum of the host animals. The necrotic changes and growth in the transplants, the blood in relation to them, and the space containing CSF were analyzed quantitatively in a developmental sequence. The histopathological changes were seen to last for 6-8 days. The neural tissues after initial regression showed recovery, and started to grow in size after 3-4 days. The transplants from 15-day donors showed the highest growth, and this was followed in sequence by those from 18- and 22-day embryos. Techniques involved in manipulation and dissection of the donor embryos, and in transplantation of the tissue, were found to play an important role in the necrotic and other changes in the transplants.