[Occupational apple and pear pollinosis among apple- and pear-growing farmers and cross-allergenicity between Japanese apple pollen and Japanese pear pollen].
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Adult↗
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[Porcine Epidemic Abortion and Respiratory Syndrome (PEARS)-positive and PEARS-negative diagnoses in pig breeding and reproduction farms in The Netherlands using statistical methods].
The diagnoses Porcine Epidemic Abortion and Respiratory Syndrome (PEARS)-positive and PEARS-negative can be made using the following data on herd performance: the average number of stillborn piglets per litter, the average number of live piglets per litter and the average piglet mortality before weaning. Depending on the number of litters used in calculating the averages, the extent to which two out of the three performance data should deviate to arrive at the diagnosis PEARS-positive is given in tables and figures. The same farm will only be diagnosed PEARS-negative if after some time at least two out of the three performance data deviate less than other criteria also provided in tables and figures.
Abortion, Veterinary↗
Degradation of endosulfan and ethion on pears and pear and grape foliage.
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Chemical Phenomena↗
Pearly penile papules: absence of human papillomavirus DNA by the polymerase chain reaction.
Pearly penile papules clinically resemble the sexually transmitted papular variant of genital condylomata. Histologically, however, pearly penile papules consist of fibropapillomata that lack the characteristic morphologic features of human papillomavirus (HPV) infection. To study the possible association of HPV infections with pearly penile papules, we examined tissue specimens from 13 men with pearly penile papules with and without associated penile condylomata. Biopsy specimens were tested for the presence of HPV DNA by the polymerase chain reaction. None of the pearly penile papules contained HPV DNA sequences, whereas four of seven cases clinically suspected of being condylomata associated with pearly penile papules contained HPV DNA. These results confirm that pearly penile papule lesions do not contain HPV DNA; therefore, the distinction between pearly penile papules and penile condylomata is clinically significant.
Adult↗
Residue analysis of DDT, malathion and kelthane on pears.
Malthion, DDT, kelthane and their mixture (3 : 10 : 5) were applied to pear fruits at the rate recommended by the Ministry of Agriculture. The rate of disappearance of their residues on pear fruits was investigated under refrigerated conditions (2 +/- 1 degree and 47% relative humidity (RH)). The same insecticides were tested in higher concentrations (1.5 and 2 times) to determine the effect of insecticides on the black spots usually found on pears after storage. No relation was found between the tested insecticides and the appearance of the black spots. Residue-disappearance curves of the three tested concentrations of these insecticides and their mixture were drawn on semi-log paper. The residues of each material found on pear fruits after one hour, 1, 8, 15, 30 and 45 days' storage in a refrigerator, estimated biologically by C. pipiens larvae and D. magna were recorded. The highest concentrations of the mixture and of the individual insecticides left higher residues on pears than the lower ones of all the insecticides either as a mixture or alone. Stored pears, refrigerated under the above conditions immediately after treatment with the mixture of insecticides recommended for the pest control of pears, cannot be consumed fresh after 45 days.
Animals↗
GA4+7 alleviates pear fruit semi-russeting partly by suppressing PRX-mediated lignin deposition.
Pear fruit semi-russeting is a surface disorder that frequently occurs during fruit development and significantly diminishes fruit appearance quality and commercial value. Although Gibberellin 4 + 7 (GA4+7) has been used to reduce fruit surface defects in horticultural crops, the physiological and molecular mechanisms underlying its inhibitory effect on pear fruit semi-russeting remain poorly understood. In this study, preharvest GA4+7 treatment of 'Cuiguan' pear significantly reduced russet coverage and lignin accumulation in mature fruit skin without adversely affecting fruit size, fruit shape index, or total soluble solids content. Integrated metabolomic and transcriptomic analyses revealed that GA4+7 treatment was associated with the repression of phenylpropanoid and lignin biosynthesis at both metabolic and transcriptional levels. Among the lignin-related differentially expressed genes, two class III peroxidase genes, PpyPRX22 and PpyPRX65, were strongly downregulated by both GA4+7 and bagging treatments. Both proteins localized to the cell wall, and transient expression assays in pear fruit skin supported positive roles for PpyPRX22 and PpyPRX65 in lignin deposition. Furthermore, dual-luciferase reporter assays combined with transient overexpression experiments suggested that several PpyMYB transcription factors may regulate PpyPRX expression and lignin accumulation, with PpyMYB138 and PpyMYB139 significantly activating PpyPRX22 and/or PpyPRX65 promoter activity. Taken together, these results suggest that GA4+7 alleviates pear fruit semi-russeting at least partly by reducing lignin deposition in the fruit skin, with PpyPRX22 and PpyPRX65 potentially contributing to this process.
Class III peroxidase↗
[Detection of fruit juice adulteration in apple and pear juice].
A method has been developed to detect the adulteration of pear juice with apples and apple juice with pears. In different varieties of apples and pears and in several commercial juices the flavonoids were examined by HPLC with respect to their quality and quantity. The chalcones phloretin glucoside and phloretin xyloglucoside are typical compounds found in apples (detection limit 7 ng). They are suitable indicators for detecting adulteration of pear juice with apples. Isohamnetin glucoside cannot be detected in apples (detection limit 10 ng), but can be used to detect pears in apple juice. The extract or juice was purified with the aid of a polyamide column. The evaporated eluate of methanol was analysed by HPLC (gradient: acetonitrile/1% acetic acid). An RP-18 column and a UV-detector were used. Additionally, the UV spectra of the compounds indicating an adulteration were recorded by a diode array detector.
Beverages↗
Prickly pear (Opuntia sp.) pectin reverses low density lipoprotein receptor suppression induced by a hypercholesterolemic diet in guinea pigs.
The effects of prickly pear pectin on plasma LDL metabolism were investigated by feeding guinea pigs either a diet containing 15 g/100 g lard and 0.25 g/100 g cholesterol (LC diet) or the LC diet in which cellulose was partially replaced (2.5 g/100 g) by prickly pear pectin (LC-P diet). The LC-P diet lowered plasma LDL cholesterol concentrations by 33% (P < 0.001). Low density lipoprotein composition was modified by intake of prickly pear pectin; the relative percentages of free and esterified cholesterol were lower and triglycerides were higher in LDL from animals fed the LC-P diet (P < 0.05). Intake of prickly pear pectin did not affect hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase activity; however, hepatic free and esterified cholesterol concentrations were lowered by 46 and 64%, respectively. Hepatic apolipoprotein B/E receptor expression (Bmax) was 60% higher in animals fed the LC-P diet (P < 0.01). Similar to the in vitro data, receptor-mediated LDL fractional catabolic rates were 190% higher in animals fed the LC-P diet (P < 0.05), whereas apolipoprotein LDL flux rates were not affected. Apolipoprotein LDL pool size and fractional catabolic rates exhibited a significant correlation (r = -0.52, P < 0.01). These data indicate that an increase in apolipoprotein B/E receptor expression is a major metabolic response by which intake of prickly pear pectin decreases plasma LDL concentrations.
Animals↗
Identification of a new viroid as the putative causal agent of pear blister canker disease.
A small RNA species with the structural and functional properties characteristic of viroids has been isolated from three different pear sources each of which induced symptoms of the pear blister canker (PBC) disease when indexed in the pear indicator A 20. A close association between this RNA and PBC disease was established, since two of the three studied sources were known to be affected by this malady only, and the viroid was not detected in healthy pear tissue. Moreover, the PBC-associated viroid (PBCVd) replicated when purified preparations were inoculated into cucumber and pear plants. PBCVd behaved in denaturing polyacrylamide gels as a circular RNA with a molecular size of approximately 315 nucleotide residues. Analysis by dot blot hybridization indicated that PBCVd shares similarities in sequence with peach latent mosaic viroid and hop stunt viroid, and to a lesser extent with apple scar skin viroid.
Electrophoresis, Polyacrylamide Gel↗
Abscisic acid promotes RBOH-dependent reactive oxygen species production and lignin biosynthesis in pears via the PuABI5-PuMYB169 module.
Pear stone cell lignification, a critical determinant of fruit texture and quality, is regulated by developmental and environmental cues, with abscisic acid (ABA) playing a central role. However, the molecular mechanisms underlying its role in reactive oxygen species (ROS)-mediated lignification remain unclear. Here, we show that PuABI5, a key component in ABA signaling, directly combines with PuMYB169, the master regulator of stone cell lignification, to modulate ROS production and lignin biosynthesis in pear fruit. Exogenous application of ABA enhances H2O2 and lignin accumulation in both pear fruits and calli, and ABA-activated PuABI5 positively regulates stone cell lignification. We demonstrate that ABA-induced PuABI5 binds directly to the PuMYB169 promoter and activates its expression to promote the transcription of PuRBOHF and lignin-related genes, thereby enhancing ROS production and lignin accumulation. Notably, PuABI5 interacted with PuMYB169 to enhance the induction of PuRBOHF expression, leading to elevated levels of H2O2, which feedback to strengthen the interaction between PuABI5 and PuMYB169. Collectively, our findings elucidate that ABA induces ROS-mediated lignification of stone cells in pears by activating the PuABI5-PuMYB169 transcriptional module.
Lignin↗
Selective effect of hormones on nucleic acid metabolism during germination of pear embryos.
1. The effect of hormones on (32)P incorporation into various RNA fractions in germinating pear embryos was studied by fractionation on methylated albumin-kieselguhr columns. Abscisic acid inhibited labelling of soluble RNA, DNA-RNA hybrid and light-ribosomal RNA fractions with (32)P and this effect was reversed by both kinetin and gibberellic acid. 2. Kinetin reversed the inhibition by abscisic acid of (32)P incorporation into total ribosomal RNA and appeared to promote labelling of heavy-ribosomal RNA. Gibberellic acid was more active than kinetin in reversing the inhibition by abscisic acid of labelling of the DNA-RNA hybrid fraction with (32)P, but in contrast with kinetin appeared to increase further the inhibition by abscisic acid of labelling of total ribosomal RNA. 3. The percentage of radioactivity in various RNA fractions showed marked variation in response to hormones. 4. The pattern of labelling of RNA in pear embryos during reversal of inhibition by abscisic acid with a combination of kinetin and gibberellic acid was similar to that after cold-treatment of dormant pear embryos. This is suggestive of hormonal interplay in dormancy release by cold-treatment in pear embryos.
Chromatography↗
[Lipoxygenases from pears, strawberries and gooseberries: partial purification and properties (author's transl)].
Membrane-bound lipoxygenases (EC 1.13.11.12) were partially purified from the fruits by centrifugation and gel chromatography. The enzymes have a pH-optimum at 6.0 (pear) resp. 6.5 (strawberry, gooseberry). Linoleic acid is oxidised to 9- and 13-hydroperoxides in a ratio of 3:7 (pear), 2:8 (strawberry) and 1:1 (gooseberry). The enzymes from gooseberries and from strawberries co-oxidise canthaxanthine with a higher specific activity than the lipoxygenases from pears and apples.
Fruit↗
[Positional specificity of the peroxidation of linoleic and linolenic acid by homogenates from apples and pears (author's transl)].
Homogenates of apples and pears were incubated (25 degrees C, 20 min) with linoleic and linolenic acid. The major products were fatty acid hydroperoxides. The ratio of 13- to 9-hydroperoxides were at least 82:18 in favour of the 13-isomer for apples and 10:90 in favour of the 9-isomer for pears. The significance of the results for the formation of flavour compounds in apples and pears is discussed.
Aldehydes↗
Pectin isolated from prickly pear (Opuntia sp.) modifies low density lipoprotein metabolism in cholesterol-fed guinea pigs.
The effect of prickly pear soluble fiber on low density lipoprotein (LDL) metabolism was investigated by feeding male guinea pigs either a nonpurified diet containing 0.25% cholesterol (HC diet) or the HC diet + 1% prickly pear pectin (HC-P diet). Plasma cholesterol levels were significantly decreased by the HC-P diet, with a 33% decrease in LDL levels (p less than 0.02) and an increase in LDL density. Hepatic free and esterified cholesterol levels were reduced 40 and 85%, respectively (p less than 0.002), by the HC-P diet. Hepatic microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase levels were not different. 125I-LDL binding to hepatic membranes was increased 1.7-fold by the HC-P diet (p less than 0.001), with receptor affinity (Kd) being unaltered and receptor number (Bmax) being significantly increased (p less than 0.001). These data suggest that prickly pear pectin may act by a mechanism similar to that of bile acid-binding resins in lowering plasma cholesterol levels. The observed reduction in LDL and hepatic cholesterol levels and increase in LDL density and hepatic apolipoprotein B/E receptors are responses suggesting an increased demand on hepatic cholesterol from increased excretion of bile acids and interruption of the enterohepatic circulation.
Administration, Oral↗
[Inhibitory effects of balsam pear on the mutagenic activity of cyclophosphamide in vivo].
Inhibitory effects of balsam pear on the mutagenic activity of cyclophosphamide were studied in the cells of bone marrow of mouse in vivo. It was found that balsam pear juice itself showed no effect on the incidence of sister chromatid exchanges (SCE) and of micronuclei (MN) on the cells of bone marrow. But balsam pear juice reduced the incidence of SCE (from 29.1 times/cell to 13.27-28.38 times/cell) and MN (from 60.0% to 27.0%-50.0%) induced by cyclophosphamide respectively. The inhibitory effects showed a dose-dependent relation, which was statistically significant.
Animals↗
Pearly penile papules: incidence.
Eight hundred forty consecutive male patients were examined for the presence of pearly penile papules. The age, race and presence or absence of circumcision were recorded. Two hundred fifty-three (30.1%) of patients had lesions, and there was a significantly increased incidence of pearly penile papules in Negroes and uncircumcised men. A significantly greater proportion of Negroes were uncircumcised, possibly explaining the racial difference. The incidence of papules was greatest in young adults and tended to decrease with increasing age. A higher percentage of men over 40 had pearly penile papules than previously reported.
Adolescent↗
Inhibition of growth and guanylate cyclase activity of an undifferentiated prostate adenocarcinoma by an extract of the balsam pear (Momordica charantia abbreviata).
We have recently described the presence of a guanylate cyclase [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2] inhibitor (GCI) in an aqueous extract of the balsam pear (Momordica charantia abbreviata). Because the guanylate cyclase-cyclic GMP system is though to be involved in cell growth, DNA and RNA synthesis, and possible malignant transformation, we examined the effect of the aqueous extract containing GCI on an undifferentiated adenocarcinoma of the rat prostate and concanavalin-A-stimulated [3H]thymidine incorporation into cultured splenic lymphocytes, a process thought to be mediated by cyclic GMP. The results demonstrate that the extract of the balsam pear blocks both the growth of the rat prostatic adencarcinoma in vitro and [3H]thymidine incorporation into DNA. DNA histograms from flow cytometry indicated that the extract containing GCI inhibited in the G2 + M phase of the cell cycle, a presumed locus of cyclic GMP effects. In addition, guanylate cyclase activity was significantly greater in the tumor than normal prostate tissue and was decreased by the extract containing GCI. Cyclic GMP levels in the tumor in culture wer also decreased by addition of the extract. It remains to be determined whether or not the anti-tumor agent and GCI are the same substance.
Adenocarcinoma↗
Alternative oxidase pathway inhibits PuWRKY7-PuHDAC15 complex to promote ester aroma synthesis in Nanguo pear.
Volatile esters are key contributors to the characteristic aroma in fruit, and their accumulation directly dictates fruit quality and consumer acceptance. The alternative oxidase pathway is known for its role in regulating fruit quality, but its molecular mechanism in ester aroma accumulation remains unclear. Here, we demonstrated that the alternative oxidase pathway acts as the dominant respiratory pathway in Nanguo pear (Pyrus ussuriensis) during ripening and promotes ester aroma accumulation by increasing histone acetylation levels of PuAAT1 (alcohol acetyltransferase 1), the key gene governing ester synthesis. Further, we identified PuHDAC15 as a critical histone deacetylase that modulates acetylation levels and interacts with the transcription factor PuWRKY7. Mechanistically, PuWRKY7 directly binds to the W-box elements in the PuAAT1 promoter. The PuHDAC15-PuWRKY7 complex acts synergistically to repress PuAAT1 transcription, thereby decreasing its histone acetylation levels and gene expression, and consequently inhibiting ester aroma accumulation in Nanguo pear. This study reveals how the alternative oxidase pathway integrates into fruit aroma formation via epigenetic regulation and gene expression, thereby providing a scientific basis for targeted improvement of fruit quality.
Plant Proteins↗