Biomedical subjects

K M Lynch

Publications and source records attributed to K M Lynch.

At least 19 recordsLinked to original sources

PubMed1996

Evaluation of an automated pyrogallol red-molybdate method for the measurement of urinary protein in rats.

Methods for quantitating urinary protein differ in their ranges of linearity, technical ease of performance, and applicability to automated analyzers. The Coomassie Brilliant Blue method is widely used but has limited linearity and its tendency to stain glassware has limited its application to automated analyzers. We evaluated a pyrogallol red-molybdate protein dye-binding method (Biotrol USA, Inc.) on a Hitachi 705 analyzer for the quantitation of urinary protein in rats. This method showed a wide range of linearity (up to 2.6 g/l) and good precision. Within-run CVs of 6.6% and 1.3% and between-day CVs of 10.9% and 1.1% were observed at mean protein concentrations of 0.16 g/l and 1.96 g/l, respectively. In addition, rat urine protein results from this method correlated well (r2 = 0.998, n = 40) with a Coomassie Brilliant Blue method (QuanTtest Blue, Quantimetrix Corporation). No significant or unexpected interferences were encountered with this method. We conclude that the automated pyrogallol red-molybdate method is an acceptable and practical alternative to the Coomassie Brilliant Blue method for the quantitation of urine protein in rats.

Animals↗

PubMed1992

Pharmacological profile of G619, a new platelet aggregation inhibitor.

G619, a 4-OH-isophthalic acid derivative, was studied for its capacity to inhibit platelet aggregation. G619 dose-dependently inhibited U46619, collagen, ADP, PAF, thrombin and epinephrine-induced platelet aggregation in vitro. The IC50 values for inhibition of U46619-induced human and rabbit platelet aggregation were 39 and 43 microM, respectively. G619, at 100 microM, inhibited high concentration collagen (10 micrograms/ml)-induced aggregation of rabbit platelets pretreated with indomethacin and increased the level of cAMP in washed rabbit platelets by 30% (p less than 0.01 vs basal). However, G619, did not inhibit fibrinogen binding to GPIIb/IIIa receptor, phosphodiesterase, U46619-induced contractile responses on canine saphenous vein or rabbit aorta, calcium-induced vasoconstriction and thrombin or PAF-induced elevation of [Ca++]i in platelets in vitro. In vivo, the U46619-induced maximal thrombocytopenia in rats was reduced from 40% (vehicle) to 22% and 18% by 10 and 30 mg/kg of G619 i.v., respectively. G619 (30 mg/kg) had no effect on the U46619-induced vasopressor response or sudden death in rats, and had no effect on TxB2 formation. Our results indicate that G619 is a broad-spectrum platelet aggregation inhibitor and may have its effect on a common mechanism for platelet aggregation besides an effect on the thromboxane A2 receptor.

Adenosine Diphosphate↗

PubMed1992

Hemodynamic, hematologic and eicosanoid mediated mechanisms in 7.5 percent sodium chloride treatment of uncontrolled hemorrhagic shock.

Hypertonic saline solution (HTS) (7.5 percent sodium chloride [NaCl]) treatment (5 milliliters per kilogram) of rats subjected to uncontrolled hemorrhagic shock (n = 7) caused an initial partial recovery of blood pressure (+38 +/- 5 percent, p<0.05) and cardiac index (+48 +/- 6 percent, p<0.01) followed by increased bleeding (+53 +/- 5 percent versus rats treated with 0.9 percent NaCl, p<0.05), secondary shock (mean arterial pressure [MAP] 23 +/- 7 millimeters of mercury, p<0.01) and decreased survival (-54 +/- 15 minutes versus control, p<0.05). The increased blood loss resulted from: 1, increased vascular pressure and vasodilatation (total peripheral resistance index -27 +/- 5 percent, p<0.05), as initial bleeding occurred when MAP and cardiac index are increased compared with the control group (+88 +/- 10 percent, p<0.05 and +82 +/- 7 percent, p<0.01, respectively) and as the concomitant infusion of angiotensin II, a potent vasoconstrictor, delayed the HTS-induced bleeding (resumed at 60 minutes), and 2, a defect in platelet aggregation reflected by decreased adenosine diphosphate (ADP)-induced maximal aggregation (-79 percent versus rats treated with 0.9 percent NaCl, p<0.05) and increased EC50 of ADP (+159 percent, p<0.05). These hemodynamic and hematologic responses might be mediated at least in part by prostacyclin, a vasodilator and antiplatelet aggregator, as HTS-treated rats markedly elevated the 6-keto-PGF1 alpha per thromboxane B2 ratio (+140 +/- 12 percent, p<0.01) and pretreatment with indomethacin decreased blood loss and improved MAP and survival. These data point out potential untoward hemodynamic and hematologic consequences of HTS treatment in traumatic injury in which control of bleeding cannot be confirmed.

6-Ketoprostaglandin F1 alpha↗

PubMed1987

Homologues of the human C and A apolipoproteins in the Macaca fascicularis (cynomolgus) monkey.

We used antisera to human A and C apolipoproteins to identify homologues of these proteins among the high-density lipoprotein apoproteins of Macaca fascicularis (cynomolgus) monkeys, and NH2-terminal analysis was used to verify the homology. The NH2-terminal sequence of the M. fascicularis apoA-I is identical with that of another Old World species, Erythrocebus patas, and differs from human apoA-I at only 4 of the first 24 residues. M. fascicularis apoA-II contains a serine for cysteine replacement at position 6 and is therefore monomeric like the apoA-II from all species below apes. Human and monkey apoA-II are not otherwise different through their first 25 residues. About 20% of M. fascicularis apoC-I aligns with human apoC-I through residue 22, and 80% lacks an NH2-terminal dipeptide. Otherwise, the monkey apoC-I differs from the human protein at only 2 of 25 positions. Two forms of M. fascicularis apoC-II were identified. ApoC-II1 is highly homologous with human apoC-II, whereas an NH2-terminal hexapeptide is absent from apoC-II2. ApoC-II2 was the predominant species, and apoC-II1 appears to represent a propeptide from which a hexapeptide prosegment is cleaved at a Gln-Asp bond. Both forms of monkey apoC-II are potent activators of lipoprotein lipase. There are two polymorphic forms of M. fascicularis apoC-III, and their electrophoretic mobilities become identical after treatment with neuraminidase. Except for a glycine for serine substitution at position 10, the first 15 NH2-terminal residues of M. fascicularis and human apoC-III are the same.

Amino Acid Sequence↗

PubMed1985

Apolipoprotein B-100 deficiency. Intestinal steatosis despite apolipoprotein B-48 synthesis.

We describe a child, the issue of phenotypically normal parents, who had fat malabsorption, both intestinal and hepatic steatosis, and serum cholesterol and triglyceride concentrations of 38 and 63 mg/dl, respectively. Lipoprotein electrophoresis, Ouchterlony double diffusion, and electron microscopy demonstrated that normal low density lipoproteins (LDL: 1.006 less than rho less than 1.063 g/ml) were absent. Lipoprotein particles in the rho less than 1.006-g/ml fraction were triglyceride rich, very large (93.2 +/- 35.1 nm), and contained the B-48 but not the B-100 apoprotein; both species of apolipoprotein (apo) B were found in the parents' lipoproteins. These chylomicrons and chylomicron remnants were present even in the patient's fasting plasma, which suggested prolonged dietary fat absorption. Plasma levels of high density lipoprotein lipids and proteins were low, and the phosphatidylcholine/sphingomyelin ratio was reduced as in typical abetalipoproteinemia. The monosialylated form of apo C-III was not identified on polyacrylamide gel electrophoresis, which suggested that this protein was elaborated only with very low density lipoproteins (VLDL). A radioimmunoassay for apo B employing a polyclonal antisera to plasma LDL gave apparent plasma apo B levels of 0.6, 66, and 57 mg/dl in the patient and his father and mother, respectively. The displacement curve generated by the parents' VLDL and LDL did not did not differ from control lipoproteins. The patient's chylomicron-chylomicron remnant fraction displaced normal LDL over the entire radioimmunoassay range, but the efficiency of displacement was strikingly less than with B-100 containing lipoproteins. If the patient's B-48 protein is not qualitatively abnormal, these results confirm very limited immunochemical cross-reactivity between at least one major epitope on B-100 and the epitopes expressed on B-48. The apo B defect in this patient appears to be recessive. It abolishes B-100 production and may additionally limit the formation of B-48.

Adult↗

PubMed1976