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PubMed1997

Lipoprotein(a) is a potent chemoattractant for human peripheral monocytes.

We have previously reported that the serine protease plasmin triggers chemotaxis in human peripheral monocytes, but not in polymorphonuclear leukocyte. We now show that the structurally related lipoprotein(a) (Lp[a]) as well as recombinant apolipoprotein(a) (apo[a]) trigger chemotactic responses in human monocytes equipotent to that observed with the standard chemoattractant FMLP. The chemotactic effects of Lp(a) and FMLP were additive. Low density lipoprotein (LDL) did not elicit any significant chemotactic response nor did it interfere with that triggered by Lp(a). As assessed by checkerboard analysis, Lp(a)-mediated monocyte locomotion was a true chemotaxis. Both plasminogen as well as catalytically inactivated plasmin inhibited monocyte migration elicited by Lp(a), suggesting binding of Lp(a) to plasminogen binding sites. Lp(a)-mediated signaling proceeds through a pertussis toxin-sensitive guanosine triphosphate (GTP)-binding protein and activation of protein kinase C as implicated by the effects of 1-O-hexadecyl-2-O-methyl-rac-glycerol and chelerythrine. Lp(a) induced generation of guanosine 3',5'-cyclic monophosphate (cGMP), apparently crucial for the Lp(a)-mediated chemotaxis, because an inhibitor of soluble guanylyl cyclase, LY83583, reduced both the Lp(a)-induced cGMP formation as well as the monocyte migration. The latter effect of LY83583 was antagonized by the stable cGMP analog 8-pCPT-cGMP. The data indicate that Lp(a) triggers chemotaxis in human monocytes by way of a cGMP-dependent mechanism. Our findings may have important implications for the atherogenesis associated with elevated levels of Lp(a).

Cells, Cultured↗
PubMed1998

Neuromodulatory inputs maintain expression of a lobster motor pattern-generating network in a modulation-dependent state: evidence from long-term decentralization in vitro.

Neuromodulatory inputs play a critical role in governing the expression of rhythmic motor output by the pyloric network in the crustacean stomatogastric ganglion (STG). When these inputs are removed by cutting the primarily afferent stomatogastric nerve (stn) to the STG, pyloric neurons rapidly lose their ability to burst spontaneously, and the network falls silent. By using extracellular motor nerve recordings from long-term organotypic preparations of the stomatogastric nervous system of the lobster Jasus lalandii, we are investigating whether modulatory inputs exert long-term regulatory influences on the pyloric network operation in addition to relatively short-term neuromodulation. When decentralized (stn cut), quiescent STGs are maintained in organ culture, pyloric rhythmicity gradually returns within 3-5 d and is similar to, albeit slower than, the triphasic motor pattern expressed when the stn is intact. This recovery of network activity still occurred after photoinactivation of axotomized input terminals in the isolated STG after migration of Lucifer yellow. The recovery does not depend on action potential generation, because it also occurred in STGs maintained in TTX-containing saline after decentralization. Resumption of rhythmicity was also not activity-dependent, because recovery still occurred in STGs that were chronically depolarized with elevated K+ saline or were maintained continuously active with the muscarinic agonist oxotremorine after decentralization. We conclude that the prolonged absence of extraganglionic modulatory inputs to the pyloric network allows expression of an inherent rhythmogenic capability that is normally maintained in a strictly conditional state when these extrinsic influences are present.

Afferent Pathways↗
PubMed1998

Apolipoprotein E2 (Arg136 --> Cys) mutation in the receptor binding domain of apoE is not associated with dominant type III hyperlipoproteinemia.

Using apoE phenotyping by immunoblotting and apoE genotyping we identified four heterozygous carriers of a rare apolipoprotein (apo) E2 variant, apoE2 (Arg136 --> Cys). ApoE2 (Arg136 --> Cys) was not distinct from apoE2 (Arg158 --> Cys) by phenotyping, but produced a unique pattern of bands on CfoI restriction typing of a 244 bp apoE gene fragment. Two of the four apoE2 (Arg136 --> Cys)/3 heterozygotes had elevated triglycerides, two were normolipidemic. The composition of very low density lipoproteins (VLDL) was normal in each of the four apoE2 (Arg136 --> Cys) carriers, regardless of the triglyceride concentrations. None of the apoE2 (Arg136 --> Cys) carriers displayed a broad beta-band and none revealed beta-migrating particles in the VLDL. The two hypertriglyceridemic carriers of apoE2 (Arg136 --> Cys) were, therefore, classified as having type IV rather than type III hyperlipoproteinemia. LDL receptor binding activities were studied using recombinant apoE loaded to dimyristoylphosphatidylcholine (DMPC) vesicles and to VLDL and from an apoE-deficient individual. LDL receptor binding of apoE2 (Arg136 --> Cys) was 14% of apoE3 and was thus higher than that of apoE2 (Arg158 --> Cys). Both apoE2 (Arg136 --> Cys) and apoE2 (Arg158 --> Cys) displayed substantial heparin binding (61 and 53% of apoE3, respectively). As the dominant apoE variants known so far are characterized by more pronounced reductions of heparin binding, we suggest that apoE2 (Arg136 --> Cys) is not associated with dominant expression of type III hyperlipoproteinemia. These findings lend support to the concept that apoE variants predisposing to dominant type III hyperlipoproteinemia differ from recessive mutations by a more severe defect in heparin binding.

Adult↗
PubMed1976

Immunologic characterization of canine factor VIII.

Canine factor VIII (FVIII) preparations isolated from cryoprecipitates by gel chromatography were pooled to provide one batch of antigen for simultaneous immunization of two rabbits and a goat. The goat and rabbit antisera had similar FVIII-neutralizing titers, but the latter had seven to ten times more precipitating titer for FVIII-related antigen (FVIII-RA). Absorption with material low in FVIII had little effect on the precipitating titer of the rabbit antibody, but it abolished the precipitating capacity of the goat antibody and caused a 20% reduction in the neutralizing titer of both antisera. Results obtained in the Laurell assay with the two different antisera were similar. This finding was true whether the FVIII-RA levels were reduced, normal, or elevated, as well as for heat-treated and frozen-thawed plasmas. Both antisera were neutralized by the same canine plasma to a similar extent. Analysis of FVIII concentrates by crossed immunoelectrophoresis suggested that canine FVIII-RA was heterogeneous, with slow-and fast-migrating components. The presence of more than one antigenic site on the FVIII complex was also supported by the disparity between the FVIII-neutralizing and -precipitating titers of goat antiserum and by the demonstration that FVIII-RA, FVIII-neutralizing antigen, and procoagulant activity varied independently.

Animals↗
PubMed2000

Increased gelsolin expression and retarded collagen lattice contraction with smooth muscle cells from Crohn's diseased intestine.

Intestinal smooth muscle cells (SMC) produce the fibrotic tissue, strictures, that characterize Crohn's disease. These SMC change their phenotype from a contractile muscle form to an inflammation-responsive form that migrates and synthesizes a collagen matrix. It is postulated that the inflammatory responsive SMC form associates differently with its surrounding collagen matrix compared to the normal SMC form. SMC derived from Crohn's diseased and uninvolved bowel were sustained in cell culture. Cultured SMC incorporated in collagen lattices have the capacity to reduce the size of that lattice, referred to as lattice contraction. At day 2, Crohn's SMC-populated collagen lattices were reduced to 21% of their initial area, while non-Crohn's SMC collagen lattices were reduced to 8%. Crohn's SMC demonstrate retarded lattice contraction compared to non-Crohn's SMC. When grown in monolayer culture, Crohn's-derived SMC cover 30% more area than non-Crohn's SMC. By Western blot analysis Crohn's SMC express more gelsolin, an actin-binding protein found elevated in cells exhibiting increased cell motility. Was the increased expression of gelsolin related to retarded collagen lattice contraction? Intracellular levels of gelsolin were elevated by the electroporation of plasma gelsolin protein into suspended non-Crohn's SMC. When incorporated in collagen lattices, gelsolin loaded cells showed retarded lattice contraction compared to SMC loaded with albumin. Crohn's SMC show increased expression of gelsolin, which may be associated with a diminished capacity to reorganize collagen fiber bundles. It is suggested that increased concentrations of gelsolin in Crohn's SMC is consistent with enhanced cell migration as a consequence of the inflammatory state of Crohn's diseased intestine.

Blotting, Western↗
PubMed2005

Smooth muscle cell matrix metalloproteinases in idiopathic pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) results from persistent vasoconstriction, smooth muscle growth and extracellular matrix (ECM) remodelling of pulmonary arteries (PAs). Matrix metalloproteinases (MMPs) are matrix-degrading enzymes involved in ECM turnover, and in smooth muscle cell (SMC) and endothelial cell migration and proliferation. MMP expression and activity are increased in experimental PAH. Therefore, this study investigated whether similar changes occur in idiopathic PAH (IPAH; formerly known as primary pulmonary hypertension). Both in situ and in vitro studies were performed on PAs from patients undergoing lung transplantation for IPAH and from patients treated by lobectomy for localised lung cancer, who served as controls. In IPAH, MMP-tissue inhibitor of metalloproteinase (TIMP) imbalance was found in cultured PA-SMCs, with increased TIMP-1 and decreased MMP-3. MMP-2 activity was markedly elevated as a result of increases in both total MMP-2 and proportion of active MMP-2. In situ zymography and immunolocalisation showed that MMP-2 was associated with SMCs and elastic fibres, and also confirmed the MMP-3-TIMP-1 imbalance. In conclusion, the findings of this study were consistent with a role for the matrix metalloproteinase-tissue inhibitor of metalloproteinase system in pulmonary vascular remodelling in idiopathic pulmonary arterial hypertension. The matrix metalloproteinase-tissue inhibitor of metalloproteinase imbalance may lead to matrix accumulation, and increased matrix metalloproteinase-2 activity may contribute to smooth muscle cell migration and proliferation. Whether these abnormalities are potential therapeutic targets deserves further investigation.

Cells, Cultured↗
PubMed1998

Chronic oral antigen exposure induces lymphocyte migration in anaphylactic mouse intestine.

Persistent diarrhea, vomiting, and dehydration are symptoms often seen in patients suffering from food allergy after chronic antigen exposure; however, the precise mechanisms involved have not been well defined. In an effort to clarify the mechanisms of the chronic intestinal changes attributable to genuine IgE-mediated anaphylactic reactions induced by orally administered antigen, a mouse model was established by s.c. implantation of a murine hybridoma capable of producing monoclonal anti-trinitrophenyl IgE antibody, and the morphologic and immunologic changes occurring in the intestine upon chronic antigen exposure were investigated. In the early stage after ingestion of the antigen, diarrhea and noticeable infiltration of mast cells as well as eosinophils into the lamina propria were observed. A substantial increase in serum histamine levels as well as an increase in leukotriene C4 synthesis in the jejunal mucosa were observed 1 h after antigen challenge. Also, the synthesis of leukotriene B4 was significantly elevated for up to 9 h after antigen challenge. The expression of both intercellular adhesion molecule-1 (ICAM-1) on mucosal vascular endothelial cells and IAd on epithelial cells was markedly enhanced, and noticeable infiltration of eosinophils and lymphocytes was also confirmed in the mouse model after chronic antigen exposure. These findings suggest that oral antigen exposure induces anaphylactic reactions in the intestine mediated by mast cells and eosinophils in response to the IgE-antigen complex in the early phase, and also induces lymphocyte migration after chronic antigen exposure.

Administration, Oral↗
PubMedDate not supplied

Characterization of the molecular forms of fibronectin in fulminant hepatic failure.

The plasma levels of the opsonic glycoprotein fibronectin are decreased in patients with fulminant hepatic failure, which may be an important factor in their impaired host-defense. Twenty-nine patients in fulminant hepatic failure were studied on admission, and the mean fibronectin level in Grade 0-2 encephalopathy was 82 micrograms per ml (range = 0 to 150) and in Grade 3-4 encephalopathy 61 micrograms per ml (range = 5 to 158) as compared to normal controls (268 micrograms per ml, range = 178 to 380, n = 62). No fibronectin degradation products could be detected in fulminant hepatic failure plasma by sodium dodecyl sulfate-gel electrophoresis on a polyacrylamide gradient (5 to 15%) followed by immunoblotting onto nitrocellulose with detection using a rabbit antihuman fibronectin antiserum visualized with a peroxidase conjugate. The plasma levels of the marker proteolytic enzyme cathepsin D were significantly elevated in fulminant hepatic failure (120 +/- 31 mU per ml per hr) as compared to the normal controls (18 +/- 2.1 mU per ml per hr, n = 10, p less than 0.01). Cross-immunoelectrophoresis of fulminant hepatic failure plasma for fibronectin on agarose plates gave an additional slower migrating peak in 15 of the 29 patients, as well as that of fibronectin, which corresponded to the fibronectin complex reported by other workers in leukemia. An intermediate gel containing antihuman fibrinogen demonstrated fibrinogen to be one component of this complex. Binding of other substances to fibronectin will reduce its apparent biological activity and may be the result of their lack of clearance by the damaged liver.

Acetaminophen↗
PubMed1987

Certain aspects of normal and abnormal motility of sphincter of Oddi.

Applications of electromyographic and endoscopic manometric techniques in experimental and clinical studies have enhanced our knowledge of the normal physiology and motility disturbances of the sphincter of Oddi. The sphincter of Oddi has an active role in coordinating the time and rate of secretion of biliopancreatic juice into the duodenum. In the opossum, the sphincter of Oddi exhibits spontaneous contractions that migrate distally along the sphincter and expels its contents into the duodenum. Although the motor activity of the sphincter of Oddi is independent from that of the duodenum, there is a correlation between the frequency of bursts of spike potentials in the sphincter of Oddi and the migrating motor complex phases in the duodenum. Abnormal motility of the sphincter of Oddi has been reported during endoscopic manometric evaluation of patients with choledocholithiasis and sphincter of Oddi dyskinesia. Patients with common bile duct stones have an increase in the frequency of retrograde propagation of phasic waves. Elevation of basal pressure as well as an increase in the frequency and amplitude of sphincter of Oddi phasic waves and the common bile duct-duodenum gradient pressure may occur in patients with sphincter of Oddi dyskinesia. Endoscopic manometric studies of the sphincter of Oddi may become an important method to diagnose sphincter of Oddi dyskinesia.

Ampulla of Vater↗
PubMed1989

Involvement of oxygen radicals and phospholipase A2 in acute pancreatitis of the rat.

The purpose of this study was to assess the involvement of oxygen radicals and phospholipase A2 in acute pancreatitis. Acute pancreatitis was induced in rats by the CCK-analogue cerulein (5 micrograms/kg.h) for 30 min, 3.5 h, and 12 h. At the end of the infusion, serum enzymes and the lipid peroxidation products conjugated dienes and malondialdehyde in the tissue were measured. Moreover, tissue samples underwent lightmicroscopical examination. After 3.5 h cerulein, an interstitial edema and a beginning accumulation of granulocytes in the pancreatic gland is observed. These changes are aggravating within 12 h, leading to tissue necrosis and migration of the granulocytes into the tissue. Concomitantly amylase and lipase increased by 15 and 35 times, respectively. Conjugated dienes and malondialdehyde increase already after 30 min cerulein and reach their highest levels after 3.5 h cerulein. At the same time the tissue activity of phospholipase A2 is elevated three fold. Rats were treated with superoxide dismutase and catalase before cerulein infusion. Treatment significantly prevents tissue necrosis, granulocyte accumulation, and edema formation. The enhanced activity of phospholipase A2, however, is unaffected by the treatment. Oxygen radicals seem to be instrumental in the development of the disease.

Acute Disease↗
PubMed2026

Immune subtyping of colorectal adenoma identifies a subtype with activated adaptive immunity ahead of progressing to cancer.

BACKGROUND: Colorectal adenomas (CRA) represent precursor lesions with varying risks of malignant transformation. However, molecular subtyping, particularly immune-related classification, remains underexplored in adenomas. This study aims to characterize the immune landscape of CRA through immune subtyping and evaluate its association with cancer progression, gene expression signatures, and functional pathways. METHODS: We conducted a retrospective analysis of transcriptomic data from multiple cohorts of CRA samples. Immune subtypes were identified using non-negative matrix factorization (NMF) based on immune-related genes. Diverse deconvolution algorithms were used to estimate immune cell infiltration. The immune status alteration in premalignant lesion was further consolidated by single-cell transcriptome data. Differential gene expression analysis was performed between subtypes, followed by functional enrichment analyses (Gene Ontology [GO] and Kyoto Encyclopedia of Genes and Genomes [KEGG]). RESULTS: Two distinct immune subtypes were identified: an immune-enriched subtype characterized by high lymphocyte infiltration and elevated expression of immune-related genes, and an immune-deficient subtype with suppressed immune activity. Differential expression analysis revealed significant upregulation of immune response genes (e.g., CD4, CD86, HLA-DRA) in the immune-enriched subtype. GO and KEGG analyses highlighted enrichments in leukocyte transendothelial migration, chemokine signaling, and antigen processing and presentation pathways. Single-cell result revealed an early occurrence of TIGIT activation and exhausted CD8 T cell features in adenoma when compared to normal tissue. CONCLUSION: This study delineates distinct immune subtypes within CRAs. The immune-enriched subtype demonstrates activated adaptive immunity and may reflect a higher potential for immune surveillance, while the immune-deficient subtype exhibits stromal features suggestive of progressive transformation. These findings provide insights into early immune microenvironment alterations and may inform strategies for risk stratification and immunoprevention in colorectal carcinogenesis.

Colorectal adenoma↗
PubMed2025

Integrating hotspot dynamics and centers of diversity: a review of Indo-Australian Archipelago biogeographic evolution and conservation.

The Indo-Australian Archipelago (IAA) is the world's preeminent marine biodiversity hotspot, distinguished by its exceptional species richness in tropical shallow waters. This biodiversity has spurred extensive research into its evolutionary and biogeographic origins. Two prominent theoretical frameworks dominate explanations for the IAA's biodiversity: the "centers-of hypotheses" and the "hopping hotspot hypothesis". The "centers-of hypotheses" posits that specific regions serve as key sources of IAA biodiversity, either through the accumulation and overlap of species from external areas or via elevated rates of local speciation. In contrast, the "hopping hotspot hypothesis" asserts that biodiversity hotspots are dynamic, shifting across geological timescales in response to tectonic and environmental changes. This review synthesizes these contrasting perspectives into an integrated framework, the "Dynamic Centers Hypothesis," which proposes that as biodiversity hotspots migrate over time, the IAA's role in generating and sustaining biodiversity has evolved, with varying contributions from different sources dominating distinct historical phases. By synthesizing the evidence for both hypotheses and incorporating recent findings, including fossil and phylogeography data, we propose the "Dynamic Centers Hypothesis" as a comprehensive and unifying explanation for the IAA's biodiversity. The review further explores biogeographic delineation, aligning tropical marine realms with the IAA's evolutionary trajectory, from its Tethyan roots to its modern Indo-West Pacific dominance. Looking forward, advances in DNA barcoding and genomics are uncovering vast cryptic diversity, revolutionizing our comprehension of IAA phylogeographic history. These discoveries underscore the imperative for a multidimensional conservation framework, integrating phylogenetic, and functional diversity, to preserve this biodiversity hotspot amid escalating global change.

Biogeography↗
PubMed1996

The immune response of sheep surgically modified with intestinal loops to challenge with Trichostrongylus colubriformis.

Aspects of the local immune response to nematode challenge were investigated in vivo in isolated loops of the upper small intestine of mature sheep that were immunised by repeated infections with Trichostrongylus colubriformis infective larvae (L3). Groups of 3 sheep were challenged either through the loop (Group 1) or orally (Group 2) with T. colubriformis L3, the third group served as unchallenged controls (Group 3). Nematode specific antibody levels, mast cell proteinase levels (SMCP) and larval migration inhibition (LMI) activity were determined in loop secretions for 4 weeks after challenge. The intestinal loops remained functional throughout the experiment. Groups 1 and 2 were re-challenged 2 weeks after the first challenge, and all 3 Groups were slaughtered 2 weeks later. Histopathological examination showed elevated numbers of globule leukocytes (GL) in both the nematode-challenged loop and unchallenged small intestine of Group 1 and small intestine of Group 2 indicating that nematode infections induce the local appearance of large numbers of GL. Oral, but not loop challenge caused increased antibody levels in loop secretions when compared to unchallenged controls. Only loop-challenged sheep showed a peak in loop fluid SMCP levels 10-13 days after the first challenge which coincided with a peak in numbers of mucosal GL. The isolated loops of all 3 groups showed highly elevated numbers of eosinophils when compared to the intact small intestine. Loop fluid of all 3 groups showed a high level of LMI activity reflecting the high level of nematode-resistance induced by the immunisation procedures. Sheep in Groups 1 and 2 were both able to expel challenge infections, and when compared to Group 3, showed higher blastogenic activity of unstimulated cells derived from a mesenteric lymph node in the region of the challenged part of the intestine. The present experiment showed that surgically constructed intestinal loops provided a model system by which the substantial changes associated with the local intestinal immune response to challenge with T. colubriformis could be investigated.

Animals↗
PubMed1990

Localization by mutational analysis of transcription factor binding sequences in the U3 region of Rous sarcoma virus LTR.

The transcription factor binding sequences in the U3 region of Rous Sarcoma virus LTR have been determined by gel retardation assays using mutant synthetic oligonucleotides. The results indicate that the factor, E2BP, specifically binds to sequences TGCAATAC and TGCAACAT, which are localized between nucleotides -222 to -215 and -203 to -196, respectively. This factor is present at elevated levels in avian QT6 cells compared to mouse 3T3 and rat 2 tk- cells. E2BP binds to a sequence that is similar or identical to the sequence recognized by rat liver C/EBP. However, the two proteins are different as judged by three criteria: (i) the E2BP complex migrates slightly faster than the E2-C/EBP complex; (ii) antibodies against C/EBP neither inhibit binding of E2BP nor form a supercomplex which migrates slower than the complex formed with the factor alone; and (iii) E2BP is heat labile whereas C/EBP is heat stable. Another factor, E3BP, which binds to a sequence from -169 to -158, in the U3 region is also detected mainly in QT6 cells but not in mouse or rat cells. These results suggest that different cell-specific factors interact with different cis-acting regulatory sequences in the U3 region of RSV LTR.

Animals↗
PubMed2004

Platinum group elements in raptor eggs, faeces, blood, liver and kidney.

The increased use of platinum group elements (PGEs) in automobile catalysts and their emission into the environment has led to a concern over environmental and particularly biological accumulation. Specimens of samples from raptors are useful for the investigation of the impact of PGEs because these birds are found in both urban and rural environments and are invariably at the top of the food chain. Platinum (Pt), palladium (Pd) and rhodium (Rh) concentrations were determined by quadrupole Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) in eggs of the sparrowhawk (Accipiter nisus) and the peregrine falcon (Falco peregrinus), and in blood, liver and kidney of the peregrine falcon, while only Pt was determined in faeces of the peregrine falcon and the gyrfalcon (Falco rusticolus). PGE concentrations were higher in blood compared to both faeces and eggs, while liver and kidney concentrations were not elevated indicating no bioaccumulation through metallothionein pathways. A significant spatial trend could only be established for Pt in faeces. The general lack of a spatial trend is probably due to the widespread distribution of automobiles and the long-range transport of nanoparticles containing PGEs, and because birds migrate and forage over large areas. No significant temporal trend could be established. Higher relative concentrations of Pd, followed by Rh and Pt, indicate a mobility gradient of Pd>>Rh>Pt.

Animals↗
PubMed1987

A novel CK isoenzyme migrating between CK-MB and CK-BB.

A CK isoenzyme migrating between CK-MB and CK-BB was detected in the serum of three patients with metastatic prostatic carcinoma. CK-BB was detected in the serum of all three patients and mitochondrial CK in two of the patients. Total CK activity was either normal or elevated, and the atypical CK isoenzyme, CK-BB and the mitochondrial CK isoenzyme were present in serum for up to 1.5 months. This atypical CK isoenzyme was not CK-MB, an albumin-ligand complex, or adenylate kinase, and was not bound to an immunoglobulin. This atypical CK isoenzyme did not contain immunologically normal CK-M subunits but had some CK-B subunits and could be a variant CK-BB or CK-MB isoenzyme. Its appearance in serum could be indicative of a serious illness.

Aged↗
PubMed2003

Short-term fasting affects locomotor activity, corticosterone, and corticosterone binding globulin in a migratory songbird.

Unpredictable events such as severe storms lead to an increase in circulating corticosterone (CORT) in breeding birds. This increase is often accompanied by elevations in foraging and irruptive behavior. We were interested in determining if acute food restriction (such as might occur during inclement weather) is a sufficient cue to elicit an increase in locomotor activity, increase CORT secretion, and/or decrease circulating levels of corticosterone binding globulin (CBG) in white-crowned sparrows (Zonotrichia leucophrys gambelii). Male Z.l. gambelii were housed individually in environmental chambers on long days (LD 20:4) to simulate breeding season daylength. Birds were fed ad libitum, and on select days, food was removed 2 h after lights on (fasted treatment), or was removed and replaced (control). We analyzed CORT and CBG levels after 1, 2, 6, 22 (lights on), and 23 h under fasted and control conditions. We also measured activity during the 23-h experiment. Activity levels were increased under fasted conditions during the daytime relative to control conditions, but activity levels did not differ between treatments during the night. Fasting as little as 1, 2, and 6 h significantly increased total CORT levels above baseline (control), although after 22 h, total CORT levels under fasted conditions matched those under control conditions. Plasma CBG decreased after the 22-h fast, and remained low after the 23-h fast. This change was sufficient to significantly elevate free CORT levels in fasted birds relative to ad libitum food conditions, despite the lack of difference in total CORT levels.

Animal Migration↗
PubMed2001

Natural immunity in recurrent aphthous ulceration.

In the present study we investigated immunophenotypes of peripheral blood lymphocytes, natural killer (NK) cell activity as well as spontaneous migration, ingestion, digestion and antibody-dependent cell-mediated cytotoxicity (ADCC) as effector functions of polymorphonuclear neutrophil granulocytes (PMNs) in 51 patients with acute stage recurrent aphthous ulceration (RAU), during remission, and 47 age-matched healthy individuals. Statistically significant lower B-lymphocyte (CD19) values were found between patients with acute RAU, and those during the remission period (P<0.001), when compared with those of the controls. Total T-lymphocyte (CD3) percentages were lower in patients with RAU, and also during the remission period, when compared with the controls (P<0.001). The percentages of CD4 lymphocytes were significantly lower in patients with RAU in comparison with those of the controls (P<0.001). T-suppressor cells (CD8) were unchanged in all three groups of participants. Significantly lower spontaneous migration and ingestion values were found in patients with acute RAU, when compared with those of the controls, and during the remission period (P<0.001). Digestion values differed insignificantly between the patients with acute RAU and during the remission period. During the remission period, digestion values were significantly elevated when compared with those of the controls (P<0.05). ADCC values were lower during the remission period (P<0.001), when compared with the values during acute RAU and with those of the controls. Significantly depressed NK activity (P<0.001) was observed in patients with acute RAU, when compared with that of the controls. During the remission period, values of NK activity were also lower (P<0.001) when compared with those of the controls. These results suggest either a specific or nonspecific immunological disorder in patients with RAU.

Adolescent↗