bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mid-Holocene Glacier Peak and Mount St. Helens We Tephra Layers Detected in Lake Sediments from Southern British Columbia Using High-Resolution Techniques
Authors: Hallett Douglas J. , Mathewes Rolf W. , Foit Franklin F. 
Published: September 2002

AbstractA Glacier Peak tephra has been found in the mid-Holocene sediment records of two subalpine lakes, Frozen Lake in the southern Coast Mountains and Mount Barr Cirque Lake in the North Cascade Mountains of British Columbia, Canada. The age–depth relationship for each lake suggests an age of 5000–508014C yr B.P. (5500–5900 cal yr B.P.) for the eruption which closely approximates the estimated age (5100–550014C yr B.P.) of the Dusty Creek tephra assemblage found near Glacier Peak. The tephra layer, which has not been reported previously from distal sites and was not readily visible in the sediments, was located using contiguous sampling, magnetic susceptibility measurements, wet sieving, and light microscopy. The composition of the glass in pumice fragments was determined by electron microprobe analysis and used to confirm the probable source of this mid-Holocene tephra layer. Using the same methods, the A.D. 1481–1482 Mount St. Helens We tephra layer was identified in sediments from Dog Lake in southeastern British Columbia, suggesting the plume drifted further north than previously thought. This high-resolution method for identifying tephra layers in lake sediments, which has worldwide application in tephrachronologic/paleoenvironmental studies, has furthered our knowledge of the timing and airfall distribution of Holocene tephras from two important Cascade volcanoes.
High-Resolution Seismic Reflection Evidence for Middle Holocene Environmental Change, Owasco Lake, New York
Authors: Mullins Henry T. , Halfman John D. 
Published: September 2002

AbstractApproximately 70 km of new decimeter-resolution seismic reflection profile data from Owasco Lake, New York define a middle Holocene (∼4600 14C yr B.P.) erosion surface in the north end of the lake at water depths as great as 26 m. Beneath the lake, post-glacial sediments are up to 9 m thick and represent about 10% of the total sediment fill. Early to middle Holocene sediments, ∼6 m thick, contain biogenic gas at the south end of the basin and a large (4 km × 300 m × 15 m) subaqueous slide deposit along the east-central portion of the lake. Late Holocene sediments are thinner or absent, particularly at the north end of the lake. The middle Holocene erosion surface may have been produced by a drop in lake level. Alternatively, it may represent a change in climate during the transition between the relatively warm Holocene hypsithermal and cool neoglacial. At this time (∼4600 14C yr B.P.) circulation in Owasco Lake appears to have evolved from sluggish to active. The increased circulation, which persists today, probably resulted from atmospheric cold fronts with strong southwesterly winds that piled up water at the north end of the lake. The increased water circulation may have been ultimately driven by decreasing insolation, which produced an increased pole-to-equator thermal gradient and thus, stronger global winds that began at the transition between the hypsithermal and neoglacial.
Evidence for Lake Formation as a Response to an Inferred Holocene Climatic Transition in Brazil
Authors: Rodrigues-Filho Saulo , Behling Hermann , Irion George , Müller German 
Published: September 2002

AbstractGeochemical, mineralogical, and palynological records from a Holocene sediment core 12.7 m long from Lake Silvana, southeastern Brazil, served to identify the source of detrital sediments within catchment soils. The lake basin was first flooded in the early Holocene (9400 14C yr B.P.), when a gibbsite-rich B soil horizon started to accumulate. Four distinct hydrologic phases are consistent with vegetational changes indicated by pollen data. Phases of slope instability (colluviation) and low lake level correspond to pollen-free intervals and point to a severe retreat of the vegetation cover. The rapid sedimentation of slope-wash sediments alternating with alluvial sediments appears to have formed a tributary fan 7.8 m thick that dammed the Lake Silvana Basin 8500 14C yr B.P., probably as a response to a drastic increase in precipitation rates.
Early Holocene Juniper Woodland and Chaparral Taxa in the Central Baja California Peninsula, Mexico
Authors: Rhode David 
Published: September 2002

AbstractA packrat midden located in the Sierra San Francisco, Baja California Sur, Mexico, dating to ca. 10,20014C yr B.P., contains remains of California juniper (Juniperus californica) and other taxa now associated with southern California chaparral. California juniper does not occur in the Sierra San Francisco today, although “relict” populations of a few chaparral taxa still occur at higher elevations. This midden record documents the early Holocene occurrence of Baja California coniferous woodland and chaparral vegetation far south of its present distribution or its previously known extent from other fossil records. Based on modern climatic tolerances of California juniper and other taxa, central Baja California experienced a mild Mediterranean-type climate at least 5°–6°C cooler than the climate of today, with at least twice the winter precipitation the region now receives.
Historic Dead Sea Level Fluctuations Calibrated with Geological and Archaeological Evidence
Authors: Frumkin Amos , Elitzur Yoel 
Published: September 2002

AbstractThe Dead Sea, the Holocene terminal lake of the Jordan River catchment, has fluctuated during its history in response to climatic change. Biblical records, calibrated by radiocarbon-dated geological and archaeological evidence, reinforce and add detail to the chronology of the lake-level fluctuations. There are three historically documented phases of the Dead Sea in the Biblical record: low lake levels ca. 2000–1500 B.C.E. (before common era); high lake levels ca. 1500–1200 B.C.E.; and low lake levels between ca. 1000 and 700 B.C.E. The Biblical evidence indicates that during the dry periods the southern basin of the Dead Sea was completely dry, a fact that was not clear from the geological and archaeological data alone.
Constructing Seasonal Climograph Overlap Envelopes from Holocene Packrat Midden Contents, Dinosaur National Monument, Colorado
Authors: Sharpe Saxon E. 
Published: September 2002

AbstractFive Neotoma spp. (packrat) middens are analyzed from Sand Canyon Alcove, Dinosaur National Monument, Colorado. Plant remains in middens dated at approximately 9870, 9050, 8460, 3000, and 0 14C yr B.P. are used to estimate Holocene seasonal temperature and precipitation values based on modern plant tolerances published by Thompson et al. (1999a, 1999b). Early Holocene vegetation at the alcove shows a transition from a cool/mesic to a warmer, more xeric community between 9050 and 8460 14C yr B.P. Picea pungens, Pinus flexilis, and Juniperus communis exhibit an average minimum elevational displacement of 215 m. Picea pungens and Pinus flexilis are no longer found in the monument.Estimates based on modern plant parameters (Thompson et al., 1999a) suggest that average temperatures at 9870 14C yr B.P. may have been at least 1° to 3°C colder in January and no greater than 3° to 10°C colder in July than modern at this site. Precipitation during this time may have been at least 2 times modern in January and 2 to 3 times modern in July. Discrepancies in estimated temperature and precipitation tolerances between last occurrence and first occurrence taxa in the midden record suggest that midden assemblages may include persisting relict vegetation.
The pure anti‐oestrogen ICI 182,780 (Faslodex™) activates large conductance Ca2+‐activated K+ channels in smooth muscle
Authors: Dick Gregory M 
Published: September 2002

Oestrogen and tamoxifen activate large conductance Ca2+‐activated K+ (BKCa) channels in smooth muscle through a non‐genomic mechanism that depends on the regulatory β1 subunit and an extracellular binding site. It is unknown whether a ‘pure’ anti‐oestrogen such as ICI 182,780 (Faslodex™), that has no known oestrogenic properties, would have any effect on BKCa channels. Using single channel patch clamp techniques on canine colonic myocytes, the hypothesis that ICI 182,780 would activate BKCa channels was tested. ICI 182,780 increased the open probability of BKCa channels in inside‐out patches with an EC50 of 1 μM. These data suggest that molecules with the ability to bind nuclear oestrogen receptors, regardless of oestrogenic or anti‐oestrogenic nature, activate BKCa channels through this nongenomic, membrane‐delimited mechanism. The identity and characteristics of this putative binding site remain unclear; however, it has pharmacological similarity to oestrogen receptors α and β, as ICI 182,780 interacts with it.British Journal of Pharmacology (2002) 136, 961–964. doi:10.1038/sj.bjp.0704807
Evidence for a GABAB receptor component in the spinal action of Substance P (SP) on arterial blood pressure in the awake rat
Authors: Brouillette Jonathan , Couture Réjean 
Published: September 2002

The activation of tachykinin NK1 receptors in the rat spinal cord produced a transient drop in arterial blood pressure followed by a more prolonged pressor effect which is mediated by the stimulation of the sympatho‐adrenal system. This study aims at characterizing the spinal mechanism of that initial hypotension occurring in awake unrestrained rats.
The initial hypotension (−18±2.0 mmHg at 1 min) and the tachycardia (110±10 b.p.m.) produced by the intrathecal (i.t.) injection of the stable NK1 receptor agonist [Sar9, Met(O2)11]‐SP (Sar9, 0.65 nmol) at T‐9 spinal cord level was inhibited by the prior injection of 65 nmol LY306740 or LY303870 (NK1 receptor antagonists). No inhibition was seen when a similar dose of antagonists was given intravenously.
The prior i.t. injection of the GABAB receptor antagonist CGP52432 (100 nmol) reduced the hypotension evoked by Sar9 (0.65 nmol) and by the GABAB receptor agonist baclofen (100 nmol). The GABAA receptor antagonist bicuculline (25 nmol, i.t.) was without effect against Sar9, and the GABAA agonist muscimol (100 nmol, i.t.) had no cardiovascular effect.
The putative involvement of other mediators (dopamine, serotonine, glycine and glutamate) in Sar9‐induced hypotension was made unlikely on the basis of various pharmacological treatments. Thus data, suggest that the transient hypotension which occurs upon the activation of NK1 receptors in the spinal cord is due to the release of GABA which in turn activates GABAB receptors to inhibit sympathetic pre‐ganglionic fibres. This mechanism may have a physiological significance in the spinal reflex autonomic control of arterial blood pressure.

British Journal of Pharmacology (2002) 136, 1169–1177. doi:10.1038/sj.bjp.0704813
Comparison of vasodilators in human internal mammary artery: ghrelin is a potent physiological antagonist of endothelin‐1
Authors: Wiley Katherine E , Davenport Anthony P 
Published: September 2002

The potential vasodilator function of the peptide ghrelin, recently identified as the endogenous ligand of the growth hormone secretagogue orphan receptor (GHS‐R), was investigated in human endothelium‐denuded internal mammary artery. The peptide endothelin‐1 (ET‐1) is a potent and long‐lasting vasoconstrictor. Comparisons were made with established and putative endogenous vasodilators to determine if any could reverse ET‐1‐induced vasoconstriction in this vessel.
Ghrelin (0.1–300 nM) potently dilated 10 nM ET‐1‐induced constrictions (pD2 8.39±0.29; EMAX 63±5.6%; n=9/14, responders/total).
ANP (pD2 7.75±0.14; EMAX 106±2.0; n=5/5) and CGRP (pD2 8.08±0.17; EMAX 76±15% n=5/6) both produced complete reversal of the constrictor response to ET‐1 (EMAX not significantly different from 100%, P>0.05 one‐sample t‐test).
The following caused partial reversal of the ET‐1 response: Adrenomedullin (n=9/9) and two peptides derived from proadrenomedullin, PAMP‐12 (n=6/7) and PAMP‐20 (n=9/9) (pD2 values 7.63±0.28, 7.97±0.23 and 8.51±0.29; EMAX 58±7.3, 54±10 and 51±7.8% respectively). Unexpectedly, amylin was only 2 fold less potent than CGRP, although there was less than 50% reversal of the ET‐1 constriction (pD2 7.86±0.30; EMAX 41±5.4%; n=7/9). CNP (n=6/6) also partially reversed constrictions to ET‐1 (EMAX 53±6.3; pD2 8.07±0.38).
BNP (n=4/5) and PGI2 (n=6/8) were weak vasodilators, since concentration‐response curves failed to reach a maximum within the range tested. PGE2 caused a small dilatation in some vessels (EMAX 17±2.1%; pD2 8.63±0.36; n=4/8).
We have demonstrated ghrelin to be an effective, endothelium‐independent vasodilator of the long‐lasting constrictor ET‐1 in human arteries producing responses similar to those of adrenomedullin (P>0.05, ANOVA).

British Journal of Pharmacology (2002) 136, 1146–1152. doi:10.1038/sj.bjp.0704815
The role of gap junctions in mediating endothelium‐dependent responses to bradykinin in myometrial small arteries isolated from pregnant women
Authors: Kenny Louise C , Baker Philip N , Kendall David A , Randall Michael D , Dunn William R 
Published: September 2002

Endothelium‐dependent responses were assessed in myometrial small arteries isolated from pregnant women, using pressure myography. Responses to bradykinin were unaffected by the combined presence of the nitric oxide synthase (NOS) inhibitor, N‐nitro‐L‐arginine methyl ester (L‐NAME, 100 μM) and the cyclo‐oxygenase inhibitor, indomethacin (10 μM). The additional presence of clotrimazole (50 μM) attenuated, but did not abolish, vasodilator responses to bradykinin. Raising extracellular [K+] (by between 1 and 15 mM) did not evoke a vasodilator response, nor did the cannabinoids, anandamide and methanandamide. Responses to bradykinin were attenuated in the presence of the gap junction inhibitors 18‐α‐glycyrrhetinic acid (18‐α GA, 100 μM), carbenoxolone (100 μM) and palmitoleic acid (50 μM). SR141716A, the CB1 receptor antagonist attenuated responses to bradykinin, but only at high concentrations (10 μM). These results suggest that gap junctional communication is involved in the nitric oxide (NO)‐ and prostanoid‐independent vasodilator responses to bradykinin in myometrial small arteries in normal pregnancy.British Journal of Pharmacology (2002) 136, 1085–1088. doi:10.1038/sj.bjp.0704817
Effects of histamine on the contractile and electrical activity in isolated lymphatic vessels of the guinea‐pig mesentery
Authors: Fox James L R , von Der Weid Pierre‐Yves 
Published: September 2002

The effect of histamine on the rate of lymphatic vessel constrictions and lymphatic smooth muscle membrane potential was examined in the guinea‐pig mesentery.
Histamine (0.01–5 μM) increased the frequency and decreased the amplitude of constrictions in lymphatic vessels under intraluminal perfusion. This response was accompanied by a depolarization of the smooth muscle membrane potential, an increase in the activity of spontaneous transient depolarizations (STDs), the proposed pacemaker for constrictions in these vessels, and an increase in the occurrence of action potentials.
Responses to histamine were inhibited by the H1 receptor antagonist pyrilamine (0.2 μM), but unaffected by NO synthase inhibition with NG‐nitro L‐arginine (L‐NOARG, 100 μM) and lysis of the endothelium.
In about 50% of the vessels, a decrease in constriction frequency, STD activity and a smooth muscle hyperpolarization were observed in response to dimaprit (10 μM), suggesting the presence of H2 receptors. These vessels had also a significantly lower basal contractile rate. Lymphatic vessel pumping was not affected by R‐α‐methylhistamine (10–50 μM), ruling out a role for H3 receptor stimulation in the histamine response.
The present results suggest a direct action of histamine on the lymphatic smooth muscle via stimulation of H1 (and in some vessels H2) receptors. H1 receptors enhance and H2 receptors slow down lymphatic pumping, the dominant effect being an increased contractile activity. Correlation of these effects with histamine‐induced changes in membrane potential and STD activity suggests the involvement of these electrical changes in the initiation of the contractile response.

British Journal of Pharmacology (2002) 136, 1210–1218. doi:10.1038/sj.bjp.0704820
Participation of 5‐HT1B receptors in the inhibitory actions of serotonin on masculine sexual behaviour of mice: pharmacological analysis in 5‐HT1B receptor knockout mice
Authors: Rodríguez‐Manzo Gabriela , López‐Rubalcava Carolina , Hen Rene , Fernández‐Guasti Alonso 
Published: September 2002

The role of the 5‐Hydroxytryptamine1B (5‐HT1B) receptor subtype in masculine sexual behaviour in mice was analysed in both 5‐HT1B receptor knockout (KO1B) and wild‐type (WT) animals.
Comparison of male copulatory behaviour of WT and KO1B strains revealed that KO1B mice become interested earlier in sexual behaviour, but require more stimulation to achieve ejaculation than its corresponding WT strain.
The pharmacological manipulation of male sexual activity in the WT strain showed that the serotonin precursor 5‐Hydroxytryptophan (5‐HTP), the 5‐HT1B agonist (1‐(m‐trifluoromethylphenyl) piperazine (TFMPP) and the 5‐Hydroxytryptamine1A (5‐HT1A) receptor agonist 8‐hydroxy‐2‐di‐n‐propylamino‐tetralin (8‐OH‐DPAT) all inhibited male copulatory behaviour in mice.
In KO1B mice, TFMPP lacked an effect, 5‐HTP exerted a mild inhibitory effect while 8‐OH‐DPAT provoked only a tendency towards a reduction in the percentage of animals that achieved ejaculation. In general, KO1B mice were less sensitive to the inhibitory actions of 5‐HTP and 8‐OH‐DPAT than the WT strain.
Based on these results, we can suggest that serotonin plays a general inhibitory role in the sexual behaviour of male mice and that both 5‐HT1B and 5‐HT1A receptor subtypes participate in the inhibitory actions of this neurotransmitter.
The absence of the 5‐HT1B receptor subtype affected both components of mouse masculine sexual behaviour, motivation and execution, further confirming the involvement of this receptor subtype in the control of this behaviour. In addition, the diminished sensitivity to serotonergic stimulation exhibited by KO1B mice suggests the occurrence of compensatory changes as a consequence of the absence of the 5‐HT1B receptor subtype.

British Journal of Pharmacology (2002) 136, 1127–1134. doi:10.1038/sj.bjp.0704827
Potentiation of slow component of delayed rectifier K+ currentby cGMP via two distinct mechanisms: inhibition of phosphodiesterase 3 and activation of protein kinase G
Authors: Shimizu Kentaro , Shintani Yutaka , Ding Wei‐Guang , Matsuura Hiroshi , Bamba Tadao 
Published: September 2002

Regulation of the slowly activating component of delayed rectifier K+ current (IKs) by intracellular guanosine 3′5′ cyclic monophosphate (cGMP) was investigated in guinea‐pig sino‐atrial (SA) node cells using the whole‐cell patch‐clamp method.
When a cell was dialyzed with pipette solution containing 100 μM cGMP, IKs started to gradually increase and reached a maximum increase of a factor of 2.37±0.39 (n=4) about 10–15 min after rupture of patch membrane. Atrial natriuretic peptide (ANP, 100 nM) also potentiated IKs, consistent with intracellular cGMP‐induced enhancement of IKs.
Bath application of a selective blocker of the cGMP‐inhibited phosphodiesterase (PDE3) milrinone (100 μM) enhanced IKs by a factor of 1.50±0.09 (n=4) but failed to further enhance IKs after a maximum stimulation by intracellular cGMP (100 μM), suggesting that blockade of PDE3 activity is involved in the enhancement of IKs. A potent but nonspecific PDE inhibitor 3‐isobutyl‐1‐methylxanthine (IBMX, 100 μM) further increased IKs stimulated by 100 μM milrinone, indicating that PDE subtypes other than PDE3 are also involved in the regulation of basal IKs in guinea‐pig SA node cells.
Bath application of 100 μM 8‐bromoguanosine 3′5′ cyclic monophosphate (8‐Br‐cGMP) increased IKs by a factor of 1.48±0.11 (n=5) and this stimulatory effect was totally abolished by cGMP‐dependent protein kinase (PKG) inhibitor KT‐5823 (500 nM), suggesting that the activation of PKG also mediates cGMP‐induced potentiation of IKs.
These results strongly suggest that intracellular cGMP potentiates IKs not only by blocking PDE3 but also by activating PKG in guinea‐pig SA node cells.

British Journal of Pharmacology (2002) 137, 127–137. doi:10.1038/sj.bjp.0704843
Expression of multidrug resistance‐associated protein 2 (MRP2) in normal human tissues and carcinomas using tissue microarrays
Authors: Sandusky G E , Mintze K S , Pratt S E , Dantzig A H 
Published: September 2002

Aims: Using tissue microarrays, this study analysed the expression of the multidrug resistance protein, MRP2, by immunohistochemistry with two different MRP2 antibodies. This is the first study to address the expression of MRP2 in various common human neoplasms.Methods and results: Immunohistochemistry was performed on zinc formalin‐fixed tissue to evaluate normal tissues and carcinomas using two antibodies against MRP2 (EAG5, a polyclonal antibody, and M2‐lll‐6, a monoclonal antibody). Immunostaining was localized in neoplastic cells mainly on the cell membrane with M2‐lll‐6 and cell membrane and cytoplasm with EAG5. In normal tissues MRP2 was expressed in liver, gastrointestinal tract, and kidney tubular epithelial cells with both antibodies. MRP2 was seen in nine of 22 renal cell carcinomas, eight of 13 gastric carcinomas, 25 of 49 breast carcinomas, 14 of 32 lung carcinomas, 39 of 50 colon carcinomas, and 16 of 17 ovarian carcinomas. There was < 10% variability between the two antibodies. MRP2 expression was highest in moderate to poorly differentiated tumours from colon, lung, gastric, and ovarian carcinomas and in grade 2 and 3 breast and renal carcinomas.Conclusion: The expression of MRP2 in many solid human tumours indicates that inherent drug resistance may play an important role as a biomarker for predictive chemotherapy treatment.
Breast hamartomas: clinicopathological and immunohistochemical studies of 24 cases
Authors: Herbert M , Sandbank J , Liokumovich P , Yanai O , Pappo I , Karni T , Segal M 
Published: September 2002

Aims:  The aim of our study was to investigate the clinical, pathological and immunohistochemical features of breast hamartomas, in order to obtain a detailed profile of this somewhat uncommon lesion.Methods and results:  This study presents a clinical, pathological and immunohistochemical analysis of 24 breast hamartomas. Four cases of fibrocystic breast changes were used as a control group. The immunohistochemical panel induced oestrogen (ER) and progesterone (PR) receptors, c‐erbB‐2 protein, p53, Ki67, CK‐MNF116, and vimentin. The patients ranged in age from 30 to 78 years (mean 48 years). All patients presented with a palpable unilateral mass. Three patients showed two hamartomas in the same breast. Tumours ranged from 20 to 50 mm in diameter. Typical macroscopic and microscopic features were noted. Immunohistochemical studies showed ER and PR receptor positivity in epithelial cells as well as in the stromal cells in all 24 cases. No c‐erbB‐2 protein over‐expression was noted. p53 expression was not observed. Ki67 showed 2–3% positivity in epithelial cells and not in stromal cells in most cases.Conclusions:  There was no association with side, ethnic origin or dietary habits. The immunohistochemistry of hamartomas is generally similar to normal breast or fibrocystic breast tissue. Ki67 together with receptor positivity may reflect some proliferative activity and explain observed faster growth of hamartoma during pregnancy and lactation.