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Biomedical subjects

L C Anderson

Publications and source records attributed to L C Anderson.

At least 73 records · Page 4Linked to original sources
PubMed1986

Lipid accumulation in the major salivary glands of streptozotocin-diabetic rats.

Four-five months after the induction of diabetes, salivary tissues of male Wistar rats were preserved by glutaraldehyde fixation or rapid freezing in dry-ice cooled hexane. Fixed tissues were either processed and embedded for light and electron microscopy, or frozen and, together with unfixed tissues, sectioned and stained with Oil Red 0 or by the calcium-lipase method. All diabetic glands had considerably more intracellular lipid than control ones. Lipid accumulation within parenchymal cells varied with the type of gland, and was more pronounced in animals with the highest serum-glucose levels. Serous cells of parotid and sublingual glands accumulated the greatest amount of lipid; lesser amounts were present in seromucous acinar cells of submandibular glands; little or none in mucous acinar cells of sublingual glands. There was no lipid in striated, granular or excretory ducts. Histochemical staining suggested that the intracellular lipid was mainly triglyceride which may accumulate by increased uptake for use as an energy source, or by decreased use in the synthesis of secretory granule and plasma-membrane material.

Animals↗
PubMed1986

Peroxidase release from rat submandibular salivary acinar cells in vitro.

Acinar cell aggregates were isolated and then incubated for 60 min with or without isoproterenol, phenylephrine, carbamylcholine, and insulin, and peroxidase activity in the cells and medium assayed. Isoproterenol stimulated the release of 70-80 per cent of total peroxidase activity. Carbamylcholine stimulation resulted in the release of only 15 per cent of this activity; phenylephrine had no effect. Insulin alone failed to stimulate peroxidase secretion, but it potentiated the response of the cells to carbamylcholine.

Animals↗
PubMed1984

Photosynthetic electron transport in guard cells of diverse species.

Guard cells of plants representing 18 species were assayed qualitatively for potential to conduct photosynthetic linear electron transport. These plants included C(3) pteridophytes, C(3) and C(4) monocots, and C(3), C(4), and Crassulacean acid metabolism dicots. By use of a microfluorospectrophotometer, guard cell samples in epidermal peels were isolated optically. Chlorophyll fluorescence was monitored from the onset of excitation light. For guard cells of all these species, fluorescence intensity increased during illumination. When samples were preincubated with 3-(3,4-dichlorophenyl)-1,1-dimethylurea, diuron, however, there was a more rapid increase in fluorescence. These results indicate that all tested guard cells conduct photosynthetic electron transport through the reaction center of photosystem II.

Journal Article↗
PubMed1984

Influence of circulating catecholamines on protein secretion into rat parotid saliva during parasympathetic stimulation.

Secretion of proteins by rat parotid glands in response to parasympathetic nerve stimulation was studied in vivo during pentobarbitone anaesthesia. Parasympathetic stimulation (3-10 Hz) via the auriculotemporal nerve resulted in a copious flow of saliva low in protein. In contrast, sympathetic stimulation (5 Hz) via the cervical sympathetic trunk evoked saliva low in volume but high in protein. Nevertheless, the specific concentrations of amylase and peroxidase (mg/mg protein) and the ratio of amylase to peroxidase remained constant. Sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis revealed a single, rapidly migrating protein band of unknown identity in proportionately greater amounts in parasympathetic saliva than in sympathetic saliva. Bilateral adrenalectomy led to reduced amylase and peroxidase secretion in response to parasympathetic stimulation both on a mg/ml and a mg/mg protein basis. SDS gel electrophoresis also demonstrated the decrease in specific amylase concentration following adrenalectomy. The ratio of amylase to peroxidase, however, was not significantly affected. Administration of 6-hydroxydopamine 17-72 h prior to adrenalectomy caused no further reduction in the secretion of amylase and peroxidase. Chronic sympathectomy of 2.5-4 months duration resulted in an increased protein secretion (mg/ml) by the parotid gland in response to parasympathetic stimulation. This increase was only slightly reduced by bilateral adrenalectomy. However, as observed in non-sympathectomized rats, adrenalectomy caused a significant reduction in the specific concentrations of both amylase and peroxidase, but did not affect the amylase to peroxidase ratios. We conclude that parasympathetic nerve stimulation of rat parotid glands after overnight starvation causes secretion of proteins in proportions similar to, but in significantly lower concentrations than those found in sympathetic saliva. Circulating catecholamines, however, influence the amount of amylase and peroxidase secreted by the rat parotid gland in response to parasympathetic nerve stimulation and account for most of the increased secretion of these enzymes following chronic sympathectomy.

Adrenalectomy↗
PubMed1984

Effect of various dietary arginine: lysine ratios on performance, carcass composition and plasma amino acid concentrations of growing-finishing swine.

Crossbred growing-finishing pigs (112 barrows, 48 gilts) were used to determine the effect of reducing excess dietary arginine, through feedstuff variation, on performance, carcass composition and plasma amino acid concentrations. Diets contained five, four, three or two times the NRC requirement for arginine. Lysine in all diets was formulated to be equal to NRC requirements, and all diets contained at least 100% of the NRC recommendations for all other essential amino acids. Initial weight, final weight and days on test for the grower phase were 26.7 kg, 44.2 kg and 28 d, respectively. Weight gain and gain/feed were not different among treatments but feed intake showed a quadratic response during the grower phase, being highest at four times the NRC requirement for arginine. Initial weight, final weight and days on test for the finisher phase were 44.2 kg, 96.9 kg and 67 d, respectively. Weight gain during the finisher phase and for the total experiment exhibited a quadratic response, being highest for the pigs fed the intermediate arginine levels. Gain/feed for the finisher phase followed the same trend as weight gain. Feed intakes for the finisher phase and total experiment were not different among treatments. Carcass data were collected on all barrows. There were no differences in hot carcass weight or adjusted average backfat among treatments. Loin eye area and percentage of lean decreased linearly as arginine level decreased in the diet. Plasma urea, arginine and orthinine concentrations decreased linearly with decreasing dietary arginine. Plasma lysine exhibited both a quadratic and a cubic response. The data indicate that reducing excess dietary arginine had little effect on performance or carcass composition and no consistent effect on plasma lysine of growing-finishing swine.

Amino Acids↗
PubMed1984

Effects of excess arginine with and without supplemental lysine on performance, plasma amino acid concentrations and nitrogen balance of young swine.

Three experiments were conducted to determine the effects of excess arginine on performance, plasma amino acid levels and N balance of young pigs (initial weights 6.9, 7.0 and 10.3 kg, respectively). In a 28-d growth trial, various amounts of arginine (0 to 1.6%) were added to a conventional starter diet. Addition of arginine decreased (P less than .01) average daily feed intake (ADFI) and gain (ADG), but had no effect on feed efficiency (G/F). Plasma urea, arginine and ornithine concentrations were elevated (P less than .001) by the increasing dietary arginine levels at d 14 and 28. Plasma histidine levels were reduced (P less than .01) at d 28. Plasma lysine levels exhibited a cubic response (P less than .05) at d 14, but were not affected by excess arginine at d 28. In a second growth trial ADFI and ADG were decreased (P less than .05), but G/F was not affected by the addition of 1.6% dietary arginine. Lysine supplementation (0, .15 or .30%) increased performance in the absence of excess arginine, but the main effect of lysine was not significant for any performance criteria. As in the first experiment, plasma concentrations of urea, arginine and ornithine were increased (P less than .001) by the addition of arginine. Plasma histidine was not affected by either arginine or lysine. Plasma lysine levels were reduced (P less than .001) by dietary arginine and increased (P less than .001) by lysine. In a N balance experiment, addition of 1.6% dietary arginine increased N digestibility, but decreased apparent biological value. Nitrogen balance was not affected by added arginine. Lysine addition did not improve any of these three indices of N utilization. The inability of lysine supplementation to alleviate any of the adverse effects of excess arginine in young swine indicates that the reduced performance is caused by a generalized amino acid imbalance, and not by a specific interference with lysine utilization in the manner of a classical arginine-lysine antagonism.

Amino Acids↗
PubMed1984

Experimental and naturally-occurring gastric foreign bodies in laboratory rabbits.

Gastric foreign bodies were induced in laboratory rabbits by orogastric infusion of a liquid latex containing radiopaque dye which polymerizes in the acid environment within the stomach to form a solid mass. The rabbits were monitored clinically and radiographically for 6 months at which time gastrotomies were performed to remove the masses, followed by a 4-week observation period. None of the 14 rabbits became ill or anorectic during the 6-month period of clinical monitoring, and all gained weight. At gastrotomy, eight rabbits had both latex bezoars and trichobezoars . Though two rabbits died post-operatively from respiratory complications, the remaining 12 rabbits recovered without complications and regained their pre-operative body weight within 4 weeks. Five of 10 rabbits necropsied 1 month after gastrotomy had gastric trichobezoars . This led to a survey of the stomachs of 208 healthy slaughter-rabbits which revealed that 48 (23.1%) had trichobezoars weighing 1 to 24 g. The data suggested that gastric trichobezoars were common in rabbits and that few animals with these foreign bodies developed chronic anorexia. In addition, there appeared to be a high likelihood that trichobezoars recur in a high percentage of rabbits within several weeks postoperatively.

Animals↗
PubMed1984

Strain differences in the susceptibility and resistance of Pasteurella multocida to phagocytosis and killing by rabbit polymorphonuclear neutrophils.

The interactions of 2 capsular serotype A and 4 serotype D strains of Pasteurella multocida with rabbit polymorphonuclear neutrophils (PMN) were compared in vitro, using a PMN phagocytic and bactericidal assay. Bacteria and rabbit PMN were incubated for 15 minutes. The suspensions were subjected to differential centrifugation and the percentage of phagocytosis (cell association) was determined from the number of viable noncell-associated bacteria. The cell pellets and the associated bacteria were resuspended and PMN bactericidal activity was calculated from the number of remaining viable cell-associated bacteria at 45 and 75 minutes after the start of the assay. Test bacteria were not opsonized or were opsonized with immune serum containing active complement. One type A strain was ingested and killed by PMN in the presence and absence of opsonins. The 5 remaining strains were resistant to PMN killing, but only the type A strain resisted phagocytosis. Resistance of the type A strain was attributed to the hyaluronic acid capsule, since pretreatment of the bacteria with hyaluronidase rendered opsonized bacteria susceptible to ingestion and killing. The pattern of resistance of the 4 type D strains was different from that of the resistant type A strain. Both opsonized and nonopsonized type D bacteria became cell associated, but none were killed by PMN. The mechanism of resistance of these 4 strains to PMN bactericidal activity is currently unknown.

Animals↗
PubMed1983

Effects of alloxan diabetes and insulin in vivo on rat parotid gland.

Parotid gland growth and secretory enzyme levels were studied in male Sprague-Dawley rats following the induction of alloxan diabetes. Diabetes resulted in a retardation of parotid gland, as well as body growth, and in a reduction of parotid gland DNA, RNA, and total protein compared with control rats. Morphologically, parotid glands of diabetic animals were characterized by an intracellular accumulation of lipid within acinar and intercalated ductal cells. Parotid amylase was reduced 40% in diabetic rats compared with control rats. In contrast, peroxidase levels increased by 54%, and DNase was unaffected. Insulin treatment of diabetic rats led to a restoration of gland and body growth. Parotid gland DNA, RNA, total protein, and secretory enzyme levels returned to control values within 7 days. Thus, insulin in vivo may play a major role in the regulation of parotid gland growth and function.

Aging↗
PubMed1983

Rat-bite fever in animal research laboratory personnel.

A laboratory animal technician experienced undulating fever, chills, and myalgia 3 days after he was bitten by a laboratory rat. The clinical symptoms subsided with antibiotic therapy, but recurrent fever, malaise, and joint pain occurred when therapy was discontinued. Streptobacillus moniliformis was cultured from the patient's blood.

Animals↗
PubMed1982

Taxonomic survey for the presence of ribulose-1,5-bisphosphate carboxylase activity in guard cells.

Guard cell pairs were dissected from freeze-dried leaves of plants representing 15 families, including monocots, dicots, and pteridophytes. All three major photosynthetic carbon pathways (C(2), C(4), and Crassulacean acid metabolism) were represented. These individual guard cell pairs were assayed quantitatively for ribulose-1,5-bisphosphate carboxylase specific activity. Assay sensitivity averaged 0.08 picomoles of ribulose-P(2) dependent P-glycerate formation (i.e. 100-fold more sensitive than required to detect the activity present in a single Vicia faba mesophyll cell). The calculated specific activities for guard cells and mesophyll cells averaged 4 and 472 millimoles per kilogram dry weight per hour, respectively. For all species surveyed, (a) the enzyme activity calculated for guard cells was below the detection limit of the assay, or (b) the specific activity (weight or cell basis) calculated for guard cells was less than 1% of the specific activity calculated for adjacent mesophyll cells. Based on this survey, the generalization is made that the photosynthetic carbon reduction pathway is absent, or virtually so, in guard cell chloroplasts.

Journal Article↗
PubMed1982

Salivary protein polymorphisms in caries-free and caries-active adults.

Several salivary proteins are known to exhibit genetic polymorphism, and this study was undertaken to determine whether there was an association of caries experience with specific parotid salivary protein phenotypes. Parotid saliva collected from 46 caries-free and 47 caries-active naval recruits was subjected to SDS, anionic, and cationic polyacrylamide slab gel electrophoresis. Distributions of the acidic proline-rich (Pr), parotid acidic (Pa), double band (Db), parotid size variant (Ps), parotid middle band (Pm), and parotid basic (Pb) protein phenotypes were similar in both caries-free and caries-active subjects. Further, overall protein patterns on SDS, anionic, and cationic slab gels did not differ between the two groups.

Dental Caries↗
PubMed1982

Diagnostic exercise.

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Adrenal Gland Neoplasms↗