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At least 19 recordsLinked to original sources
PubMed1979

Comparison of the stimulatory effects of ovine, porcine and human follicle-stimulating hormone and of ovine and human luteinizing hormone on the accumulation of cyclic AMP by porcine granulosa cells.

The effects of ovine, porcine and human FSH, and ovine and human LH on the accumulation of cyclic AMP by porcine granulosa cells obtained from follicles at various stages of maturation were investigated. During incubation periods of 15 min, 10 micrograms ovine FSH pretreated with antiserum to LH or 10 micrograms human FSH resulted in an 11- to 18-fold, five- to ninefold, and less than a twofold increase in intracellular accumulation of cyclic AMP by granulosa cells from small (1--2 mm), medium (3--5 mm) and large (6--12 mm) follicles respectively. Similar patterns of response occurred with addition of porcine FSH. After incubation for 30 and 60 min with ovine, porcine or human FSH, significant accumulation of cyclic AMP in the incubation medium occurred with cells obtained from small and medium-sized follicles. After 60 min of incubation with FSH the accumulation of cyclic AMP in the incubation medium exceeded the intracellular cyclic AMP levels in granulosa cells from small and medium-sized follicles. During incubation periods of 15 min, 1.0 micrograms ovine LH resulted in less than a twofold, a fourfold and greater than a tenfold increase in intracellular accumulation of cyclic AMP by granulosa cells from small, medium and large follicles respectively. Addition of human LH brought about a similar response. Incubation periods of 30 and 60 min with 1.0 micrograms ovine or human LH resulted in significant accumulation of cyclic AMP in the incubation medium by granulosa cells from large follicles; cyclic AMP content in the incubation medium was greater after 60 min compared with 30 min of incubation. It was concluded that ovine FSH pretreated with an antiserum to LH had similar effects on cyclic AMP levels as did purified human and porcine FSH, and that the stimulatory effects of the less pure ovine FSH were probably not due to an impurity in the FSH preparation. Porcine granulosa cells obtained from small follicles should be suitable as an in-vitro FSH bioassay while granulosa cells obtained from large follicles should be suitable as an in-vitro LH bioassay.

Animals↗
PubMed1978

Study of follitropin receptors in testis using a homologous system. Binding of porcine follitropin to plasma membranes from immature porcine testis and correlation with adenylate cyclase stimulation.

The properties of follitropin receptors in immature porcine testis were determined using highly purified porcine follitropin. 1. The characteristics of follitropin binding to a subcellular fraction rich in plasma membranes were studied using a 125I-labelled follitropin with high specific activity (75-100 Ci/g) and high binding activity. The binding is dependent on time, temperature and pH. It is specific to follitropin as demonstrated by the very low binding activity of the follitropin alpha and beta subunits and of the other glycoprotein hormones. Scatchard analysis of binding data indicated an equilibrium association constant of 2 x 10(10) M-1 and a concentration of high affinity binding sites of 500 fmol/mg membrane proteins. 2. A sensitive radio-ligand receptor assay was developed. Fifty percent inhibition of binding was obtained with as little as 2 ng of porcine follitropin. Ovine and bovine follitropins and pregnant mare serum gonadotropin gave binding inhibition curves parallel to that given by porcine follitropin. With equine and human follitropin, significantly different slopes were recorded. 3. Kinetics of dissociation of labelled follitropin from its testis receptors showed the presence of at least two compartments with fast and slow dissociation rate constants. The ratio between the sizes of the slow and fast compartments appeared dependent upon preincubation time. 4. A temporal correlation was observed between binding of follitropin to testis receptors and activation of membrane bound adenylate cyclase.

Adenylyl Cyclases↗
PubMed1978

Morphogenesis of porcine rotavirus in porcine kidney cell cultures and intestinal epithelial cells.

The morphogenesis of porcine rotavirus was similar in vitro in porcine kidney (PK) cell cultures and in vivo in porcine epithelial cells as examined by electron microscopy. Infected cells contained cytoplasmic, non-membrane-bound viroplasm and accumulations of virus particles within cisternae of the rough endoplasmic reticulum (RER). Three types of virus particles were noted: double-shelled or complete particles which averaged 77 nm in diam.; single-shelled or naked particles which ranged from 50 to 55 nm in diam.; and electron-dense nucleoids, or cores, 31 to 38 nm in diam. Virus particles acquired outer shells by budding through either matrices of granular, electron-dense viroplasm or membranes of distended RER. Accumulation of numerous single-shelled particles was observed only in PK cell cultures containing a high percentage of infected cells. In these cells, virus release occurred through disruption of the plasma membrane. Tubules, similar in diameter to the single-shelled particles, were observed in the nuclei of a few infected PK cells.

Animals↗
PubMed1977

Colonization of porcine intestine by enterotoxigenic Escherichia coli: selection of piliated forms in vivo, adhesion of piliated forms to epithelial cells in vitro, and incidence of a pilus antigen among porcine enteropathogenic E. coli.

In contrast to K88-positive porcine enterotoxigenic Escherichia coli (ETEC), K88-negative porcine ETEC strains did not adhere to isolated intestinal epithelial cells in vitro. However, they did adhere to intestinal epithelium in vivo. Growth of one such ETEC (strain 987) in pig small intestine consistently yielded a greater percentage of piliated cells than did growth in vitro. This increase was demonstrable by electron microscopy, by change in colonial morphology, and by agglutination in specific antisera against the pili of strain 987. In contrast to the stored stock culture (which contained very few piliated cells), richly piliated forms of strain 987 did adhere to isolated intestinal epithelial cells in vitro. A series of porcine E. coli strains was tested for agglutinability in antiserum against the pili of strain 987, and several K88-negative ETEC strains were agglutinated. These data are consistent with the hypothesis that pili facilitate intestinal adhesion and colonization by K88-negative ETEC strains.

Antigens, Bacterial↗
PubMed1975

Porcine parvovirus: frequency of naturally occurring transplacental infection and viral contamination of fetal porcine kidney cell cultures.

The frequency of naturally occurring transplacental infection of swine with porcine parvovirus (PPV) and one of the possible consequences of such infection--the presence of PPV in cell cultures prepared from fetal tissues--were investigated. Transplacental infection was indicated by the presence of high titers of hemagglutination inhibiting (HI) antibody for PPV in serums of 0-day-old, hysterectomy-derived, colostrum-deprived pigs of 3 of 82 litters. All letters were farm-raised dams. Moreover, cell cultures prepared from 3 of 49 lots of fetal porcine kidneys (FPK) collected from an abattoir during an interval of 14 months were found contaminated with PPV. Because each lot was usually comprised of kidneys from 2 litters, the latter finding suggests that 3 of approximately 98 litters were infected. Prior infection of FPK cell cultures with PPV resulted in only slight interference of replication of other selected viruses; i.e., porcine enterovirus (PEV), pseudorabies virus (PRV), vesicular stomatitis virus (VSV), and hemagglutinating encephalomyelitis virus (HEV). Moreover, PPV and HEV were propagated in the same cell cultures during 5 serial passages of the viruses. In contrast, when copropagation of PPV and VSV was attempted, PPV was not detected after the 2nd serial passage.

Animals↗
PubMed1977

Porcine A blood group-specific N-acetylgalactosaminyltransferase. I. Purification from porcine submaxillary glands.

The membrane-bound N-acetylgalactosaminyltransferase from porcine submaxillary glands which provides A blood group specificity to mucin has been purified 38,000-fold by affinity chromatography on UDP-hesanolamine-agarose in aqueous Triton X-100. Design of a suitable purification procedure was developed by assessing the strength of interaction between enzyme and affinity adsorbent using batch desorption. The pure transferase has an apparent molecular weight of 100,000 as judged by zonal centrifugation and by sodium dodecyl sulfate polyacrylamide gel electrophoresis in the absence of a reducing agent. The reduced and carboxymethylated protein has an apparent molecular weight of 46,000 and 57,000 as judged by sedimentation equilibrium and sodium dodecyl sulfate polyacrylamide gel electrophoresis, respectively, suggesting that the native enzyme contains two subunits. It is a glycoprotein with a specific activity of 30 micronmol/min/mg of enzyme, which is 55,000 times that reported for the same enzyme isolated from human serum.

ABO Blood-Group System↗
PubMed1975

Purification and partial characterization of human and porcine C3a anaphylatoxin.

C3a anaphylatoxin is a protein fragment generated enzymatically in serum during activation of the third component of complement (C3). A four-step procedure is described for the purification of human and porcine C3a anaphylatoxins from their respective sera after activation with inulin. Because serum carboxypeptidase rapidly inactivates C3a, the inhibitor epsilon-aminocaproic acid (EACA) was added during C3 activation, thus permitting isolation of fully active C3a anaphylatoxins directly from serum. A 2000-fold purification of C3a was achieved with an average 30% recovery assuming total conversion of C3 during treatment of serum with inulin. Human C3a anaphylatoxin obtained through the action of the C3 activating enzyme of the "alternate" pathway appeared nearly identical with the C3a obtained from isolated C3 after treatment with the C4,2 enzyme of the "classical" pathway or with trypsin. Comparisons were made between various properties of human and porcine C3a anaphylatoxins. The molecular weights differed only slightly. Electrophoresis on a cellulose acetate strip at pH 8.6 indicated a difference of approximately one net charge between human and porcine C3a, with the human anaphylatoxin exhibiting the more basic behavior. Although the amino acid compositions are similar, significant differences exist. The most marked difference was the total absence of threonine residues in porcine C3a. The NH2-terminal sequences of 20 amino acid residues were examined; homology existed for 16 of the 20 positions. Although partial analysis of the primary structure of human and porcine C3a indicates approximately 80% homology, no immunological cross-reactivity between the anaphylatoxins could be detected with antisera produced to either human or porcine C3a. In spite of the structural differences, the biological activities of porcine and human C3a were essentially identical. Smooth muscle contraction, increase in vascular permeability, and release of histamine from mast cells were similarly induced by equal amounts of anaphylatoxin from either human or porcine origin. Porcine C3a, like human C3a, was shown to contain a COOH-terminal arginyl residue essential for smooth muscle contraction and for induction of histamine release from mast cells. The sequence adjacent to the COOH-terminal arginine was Leu-Ala-Arg-COOH for both humans and porcine C3a. Current evidence suggests common mechanisms exist for the generation of C3a in various animal species and that the two known C3 activating enzymes in serum exhibit trypsin-like specificity.

Amino Acid Sequence↗
PubMed1979

Isolation and characterization of antithrombin III from human, porcine and rabbit plasma, and rat serum.

1. Human, porcine, rabbit, and rat antithrombin III have been purified by affinity chromatography using heparin-agarose. The amino acid and carbohydrate compositions, amino-terminal sequences, immunological cross-reactivities, and inhibitions of human thrombin were studied. 2. Human, porcine, rabbit, and rat antithrombin III are single-chain glycoproteins containing hexose, glucosamine, and neuraminic acid. 3. The total carbohydrate contents were 17, 16, 14, and 15% for human, porcine, rabbit, and rat antithrombin III, respectively. 4. Molecular weights estimated from the migration in sodium dodecyl sulfate (SDS)-poly-acrylamide gel electrophoresis were 59,000, 58,000, 63,000, and 63,000 for human, porcine rabbit, and rat antithrombin III, respectively. 5. These four proteins have similar amino acid compositions, although some minor differences were noted. 6. Human, porcine, and rabbit antithrombin III have a histidine residue at the amino-terminus, while rat antithrombin III contains an amino-terminal asparagine residue. 7. The amino-terminal sequences up to the first 17 residues showed high homology among the four proteins. 8. Some immunological cross-reactivity was observed only between human and porcine antithrombin III. 9. The apparent dissociation constants (KI) for the complexes between human thrombin and human, porcine, rabbit, and rat antithrombin III were about 1.2 x 10(-10) M, 9.5 X 10 (-9) M, 1.4 X 10(-7) M, and 2.8 X 10(-9) M, respectively.

Amino Acid Sequence↗
PubMed1978

Porcine follitropin. Isolation and characterization of the native hormone and its alpha and beta subunits.

The properties of porcine follitropin and its subunits which have not yet been characterized are presented. The porcine follitropin obtained has a biological potency of 81 times the National Institutes of Health Porcine Follitropin P-1 preparation. Its contamination by lutropin and thyrotropin amounted to 1 and 0.5 percent by weight respectively, as measured by radioimmunoassay. The alpha and beta subunits of porcine follitropin were obtained by incubation in an acidic urea solution followed by anion exchange chromatography. The amino acid composition of porcine follitropin alpha subunit was found to be identical to that of alpha chain of porcine lutropin and thyrotropin. These porcine alpha chains differ, nevertheless, markedly in their carbohydrate composition particularly with respect to their mannose and galactose contents. The amino-terminal residue of the follitropin alpha subunit is threonyl. The carboxy-terminal end of the alpha chain is of variable length. Cysteyl residue was detected at the aminoterminal end of the follitropin beta chain with glutamic acid at its carboxy-terminal end. Cross-contamination of the alpha and beta subunit preparations was measured by specific radioimmunoassay and amounted to 0.5 and 0.1 percent by weight respectively.

Amino Acids↗
PubMed1978

Thromboembolism in mitral porcine valve recipients.

A low incidence rate of thromboembolism has been reported in mitral porcine valve recipients. In contrast, 5 of 22 single mitral porcine valve recipients (23 percent) followed up in our clinic for a mean of 16 months had thromboembolic events. All patients but one were receiving long-term anticoagulant therapy. One thromboembolic event resulted in death, three in permanent neurologic deficits and one in a peripheral arterial occlusion. All five patients with emboli had atrial fibrillation and left atrial enlargement. Three had thromboembolic events before porcine heart valve implantation. In addition, five mitral porcine valve recipients who were not receiving anticoagulant therapy were examined at autopsy. Thrombus was identified in the left atrium in three patients, at the tissue-valve interface (sewing ring) in two, on the porcine valve cusps in one and in the right atrium in one. Factors influencing thrombus formation such as left atrial enlargement, atrial fibrillation and a prosthetic device are present after mitral porcine valve implantation and are indications for long-term anticoagulation therapy.

Adult↗
PubMed1978

The preparation of trypsins and chymotrypsins from bovine and porcine residues after insulin extraction.

Bovine and porcine pancreatic residue, remaining after the extraction of insulin, has been used to prepare a proteinase powder. This powder was used as a source of trypsin and chymotrypsin. The individual enzymes were isolated and purified by chromatography on sulfopropyl (SP) - Sephadex C-25 and affinity chromatography on soybean trypsin inhibitor (STI) - Sepharose. The bovine proteinase powder contained alpha-chymotrypsin, trypsin and chymotrypsin B in the ratio 5 : 2 : 1. The porcine powder contained cationic trypsin, anionic trypsin and cationic chymotrypsin in the ratio 5 : 1.4 : 3. The isolated enzymes were characterized and found to be identical with enzymes isolated from fresh tissue with the exception of porcine chymotrypsin. Porcine cationic chymotrypsin was isolated as two distinct forms, A-1 and A-2, which appear to be different activation products of porcine chymotrypsinogen A. Both forms resemble bovine alpha-chymotrypsin, a three chain structure, rather than porcine chymotrypsin Api, a two chain structure. Futhermore, the B-chain appears to be cleaved, possibly at residues Phe89-Lys90.

Amino Acids↗
PubMed1977

Thyrotropin binding to and adenylate cyclase activity of porcine thyroid plasma membranes.

Plasma membranes have been purified from porcine thyroid gland homogenate by discontinuous sucrose gradient centrifugation. The preparations contained specific binding sites for thyrotropin but not for luteinizing hormone or the beta subunits of thyrotropin and luteinizing hormone. Optimum conditions of 125I-labeled thyrotropin binding were pH 6.0-6.5 and 37 degrees C. Thyrotropin binding was reduced by divalent (Ca2+, Mg2+) and monovalent cations (Na+, K+, Li+), 50% inhibition being obtained at 10 mM and 50 mM respectively. Displacement curves of 125I-labeled bovine or porcine thyrotropin by the unlabeled hormone from three species was in the order of increasing concentrations (bovine greater than porcine greater than human) which is the order of decreasing biological activity of these hormone preparations in the assay in vivo in the mouse. The validity of the results was established by controlling that porcine membranes bound the native and the 125I-labeled hormones with equal affinity. A single type of high-affinity (Kd = 0.28 nM) binding sites was detected for bovine and porcine thyrotropins. In contrast, porcine plasma membranes bound human thyrotropin with a lower affinity (Kd = 70 nM). A good correlation was found at equilibrium and in the conditions of the cyclase assay, between receptor occupancy and adenylate cyclase activation for the three hormones.

4-Nitrophenylphosphatase↗
PubMed1979

Very pure porcine insulin in clinical practice.

In a one-year follow-up study the insulin dose in diabetic patients using very pure porcine insulin was compared with that in patients using conventional preparations. The dose of insulin used to obtain diabetic control was reduced by 7% in 108 patients treated solely with very pure porcine insulin from the start of insulin treatment when compared with 108 matched patients who had received conventional insulins. In 117 patients whose treatment had been changed from conventional bovine or bovine-porcine insulin to very pure porcine insulin the dose was reduced by 9%. A further 511 patients receiving conventional insulins were examined for local cutaneous or subcutaneous abnormalities at insulin injection sites. Lipoatrophy was found in 49 of these patients (10%), but not in patients using very pure porcine insulin. The results confirm that very pure porcine insulin reduces the insulin dose needed to maintain diabetic control and may resolve or prevent local reactions such as lipoatrophy. Long-term advantages in reduced antigenicity to insulin and contaminating peptides remain to be established.

Adolescent↗