Vortex dynamics in self-dual Chern-Simons-Higgs systems.
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Journal Article↗
Biomedical subjects
K Lee
Publications and source records attributed to K Lee.
Left ventricular diastolic dysfunction in lymphocytic myocarditis as assessed by Doppler echocardiography.
Pulsed-wave Doppler echocardiography of left ventricular (LV) inflows was performed in 30 consecutive patients with biopsy-proven lymphocytic myocarditis. There were 21 men and 9 women (mean age 50 +/- 15 years). LV ejection fraction was < or = 30% in 73% of the patients. Sixty-six percent were in New York Heart Association functional class III to IV. Peak early (E) velocity, late (A) velocity, deceleration time and filling pattern were assessed. These values were compared with a control population. E velocity in lymphocytic myocarditis was significantly higher than in control subjects (79 +/- 34 vs 67 +/- 14 cm/s, p = 0.0034). A velocity was lower in patients with myocarditis than in control subjects (38 +/- 20 vs 49 +/- 12 cm/s, p = 0.0001). Correspondingly, the E/A ratio was greater in the myocarditis group (2.5 +/- 1.3 vs 1.5 +/- 0.5, p < 0.0001). In particular, mean deceleration time in patients with myocarditis was significantly lower than that of control subjects (151 +/- 52 vs 194 +/- 30 ms, p < 0.0001). Diastolic filling patterns were abnormal in 29 of 30 patients (97%) with lymphocytic myocarditis, revealing a restrictive pattern in 25, abnormal relaxation in 4 and a normal pattern in 1. Lymphocytic myo-carditis is therefore associated with LV diastolic dysfunction of a predominantly restrictive pattern.
Adult↗
Histochemical demonstration of hydrogen peroxide production by leukocytes in fixed-frozen tissue sections of inflammatory lesions.
The production of H2O2 by cells in cold paraformaldehyde-fixed frozen sections of inflammatory lesions was histochemically demonstrated by incubating them with diaminobenzidine (DAB) for 2 to 6 h. Catalase (150 micrograms/ml, about 1400 U/ml) inhibited the reaction, indicating that H2O2 was required to produce the chromogenic DAB product. Granulocytes (PMNs and eosinophils) were the main types of cells stained by the DAB reaction. Positive staining of macrophages was less frequent. The H2O2 was produced by metabolic enzymes that were still active after cell death and mild fixation. An atmosphere of 95 to 100% oxygen enhanced the specific DAB reaction, and an atmosphere of 100% nitrogen eliminated it. The DAB histochemical reaction to detect H2O2 requires the presence of peroxidases to produce the colored reaction product. Within our tissue sections, such peroxidases were evidently present in excess, because addition of low concentrations of H2O2 significantly increased the reaction product. Although some of the H2O2 produced by the granulocytes may have been derived from the dismutation of superoxide (O2-), the NADPH oxidase pathway for O2- formation did not seem to be involved: NADPH oxidase, a rather labile enzyme, should not be active after mild fixation, and diphenyleneiodonium (100 microM), an inhibitor of flavine-requiring NADPH oxidase, did not inhibit the reaction. Reactive nitrogen intermediates were also not involved, because NG-monomethyl-L-arginine and NG-nitro-L-arginine methyl ester, inhibitors of nitric oxide synthetase, did not appreciably inhibit the reaction. We conclude that stable, non-flavine-requiring oxidases, possibly cyclooxygenases or lipoxygenases, produced the H2O2 measured histochemically by our DAB reaction. These studies were made on tissue sections of acute dermal inflammatory lesions produced in rabbits by the topical application of 1% sulfur mustard [bis(2-chloroethyl) sulfide] in methylene chloride. Both intact PMNs and disintegrating PMNs in the base of the crust produced H2O2. Despite the production of H2O2 and the presence of peroxidase activity, no tissue damage was seen microscopically near the H2O2-producing cells, which indicates that the tissues are well protected by the antioxidants present in this self-limiting inflammatory reaction.
Amitrole↗
Germ cell-specific proteins interact with the 3' untranslated regions of Prm-1 and Prm-2 mRNA.
The testis-specific mouse protamine genes (Prm-1 and Prm-2) are transcribed in haploid round spermatids, their mRNAs stored as cytoplasmic ribonucleoprotein particles and translated about 1 week later in elongating spermatids. We have compared the in vitro translational efficiencies of deproteinized Prm-1 mRNA isolated from purified populations of germ cells and found that Prm-1 mRNA from round spermatids translates as efficiently as Prm-1 mRNA from elongating spermatids, suggesting that translation of Prm-1 mRNA is normally repressed in round spermatids. Previous studies in transgenic mice have shown that the 3' UTR of Prm-1 mRNA is necessary and sufficient for its translational control (Braun et al., 1989). In this manuscript, we have used an RNA band shift assay to identify an activity, present in cytoplasmic fractions of meiotic spermatocytes and postmeiotic round spermatids, that binds the 3'UTRs of both Prm-1 and Prm-2 mRNA. We have used 3' UTR deletion variants to map the binding site to a 22-nt region within the Prm-1 3' UTR and to a 20-nt region within the Prm-2 3' UTR. uv cross-linking of the RNA band shift activities detected with the Prm-1 and Prm-2 3' UTRs generated the same two RNA/protein complexes of 53 and 55 kDa. The presence of the binding activity in the cell type and subcellular compartment associated with Prm-1 and Prm-2 mRNA storage suggest that the activity may be actively engaged in translational repression of these mRNAs.
Animals↗
A short sequence upstream of the 5' major splice site is important for encapsidation of HIV-1 genomic RNA.
A series of linker scanning and deletion mutations has been constructed in the 5' leader sequence of HIV-1. One virus with a 13-base-linker substitution upstream of the 5' major splice site was as impaired in its ability to replicate as a virus with a large deletion, which included these 13 bases, and was less efficient in packaging its genomic RNA than viruses carrying mutations between the 5' major splice site and the gag translation initiation site. These observations have led to the identification of a conserved pattern of repeated sequence elements associated with sequences experimentally defined as necessary for encapsidation of Moloney murine leukemia virus, spleen necrosis virus, avian leukosis-sarcoma viruses, and human immunodeficiency virus type 1.
Capsid↗
Genes encoding oleosins in maize kernel of inbreds Mo17 and B73.
We have investigated all three oleosin genes which are expressed in the kernel of maize (Zea mays L., Mo17). Oleosin genes, ole16, ole17, and ole18, encode OLE16, OLE17, and OLE18, respectively, in proportional amounts of approximately 2:1:1 in isolated oil bodies. None of the three genes has an intron or a sequence encoding an N-terminal signal peptide. The three genes are expressed coordinately during seed maturation, and their encoded oleosins are present in similar proportional amounts in oil bodies isolated from the embryonic axis, scutellum, and aleurone layer. OLE16 represents one oleosin isoform, whereas OLE17 and OLE18 are close members of another oleosin isoform. ole16 and ole18 have been mapped to single loci on chromosomes 2 (near b1 gene) and 5S (near phya2), respectively. We predict that ole17 is located on chromosome 1 (near phya1), in a chromosomal segment duplicated on chromosome 5.
Amino Acid Sequence↗
Oleosins in the gametophytes of Pinus and Brassica and their phylogenetic relationship with those in the sporophytes of various species.
Oleosins, which are structural proteins on the surface of intracellular oil bodies, have been found in the sporophytic seeds of angiosperms. Here, we report an oleosin from the female gametophyte of gymnosperm Pinus ponderosa Laws. seed and another oleosin from the male gametophyte of Brassica napus L. With the pine seed gametophyte, we identified two putative oleosins of 15 and 10 kDa, which are similar to the oleosins in angiosperm seeds in terms of their presence in the oil bodies in massive quantity. The complete sequence of the cDNA encoding the gametophytic 15-kDa oleosin was obtained, and it has a predicted amino-acid sequence similar to those of oleosins in angiosperm sporophytic seeds. A Brassica napus pollen cDNA sequence, which was reported earlier, would encode an amino-acid sequence somewhat similar to those of seed oleosins. We tested if the dissimilarity signifies a substantially different oleosin in the Brassica male gametophyte or an analytic error. By direct sequencing of a polymerase chain reaction (PCR)-amplified fragment of genomic DNA, we obtained evidence showing that this reported dissimilarity is likely to have arisen from a sequencing error. Our predicted sequence of the Brassica pollen oleosin has all the structural characteristics of seed oleosins. A phylogenic tree of 20 oleosins, including those from sporophytic and gametophytic tissues of angiosperm and gymnosperm, was constructed based on their amino-acid sequences. We discuss the evolution of oleosins, and conclude that oleosins are ancient proteins with multiple lineages whose root cannot be determined at this time.
Amino Acid Sequence↗
Stimulation-evoked saccades from the dorsomedial frontal cortex of the rhesus monkey following lesions of the frontal eye fields and superior colliculus.
This study examined whether signals for the generation of eye movements from the dorsomedial frontal cortex (DMFC) reach brainstem oculomotor centers either through the frontal eye fields (FEF) or through the superior colliculi (SC). The DMFC was stimulated when the monkeys studied were intact and after either one FEF or one SC was ablated. Following lesions of either the FEF or SC, the topographic order of the DMFC was largely preserved. After either lesions, stimulation of anterior DMFC sites still evoked saccades that terminated in contralateral space, and stimulation of posterior DMFC sites still evoked saccades that terminated in central space. The probability of evoking saccades decreased and the latency to evoke saccades increased as fixation neared the termination zone (a restricted region within craniotopic space) both before and after either lesion. Ablation of the SC, but not of the FEF, eliminated the saccadic inhibition to visual targets which resulted when the DMFC was stimulated in the intact animal. The findings suggest that additional channels besides those coursing through the FEF and SC are utilized by the DMFC to access the saccade generator in the brainstem.
Animals↗
Effects of chemical modification of amino and sulfhydryl groups on KATP channel function and sulfonylurea binding in CRI-G1 insulin-secreting cells.
The effects of several group-specific chemical reagents were examined upon the activity of the ATP-sensitive potassium (KATP) channel in the CRI-G1 insulin-secreting cell line. Agents which interact with the sulfhydryl moiety (including 1 mM N-ethyl-maleimide (NEM), 1 mM 5,5'-dithio-bis-(2-nitrobenzoic acid) (DNTB) and 1 mM o-iodobenzoate) produced an irreversible inhibition of KATP channel activity when applied to the intracellular surface of excised inside-out patches. This inhibition was substantially reduced when attempts were made to eliminate Mg2+ from the intracellular compartment. ATP 50 microM and 100 microM tolbutamide were each shown to protect against the effects of these reagents. The membrane impermeable DNTB was significantly less effective when applied to the external surface of outside-out patches. Agents which interact with peptide terminal amine groups and epsilon amino groups of lysine [1 mM methyl acetimidate and 1 mM trinitrobenzene sulfonic acid (TNBS)] and also the guanido group of arginine (1 mM methyl glyoxal) produced a Mg(2+)-dependent irreversible inhibition of KATP channel activity which could be prevented by ATP but not tolbutamide. The irreversible activation of the KATP channel produced by the proteolytic enzyme trypsin was prevented only when methyl glyoxal and methyl acetimidate were used in combination to inhibit channel activity. Radioligand binding studies showed that the binding of 3H glibenclamide was unaffected by any of the above agents with the exception of TNBS which completely inhibited binding with a EC50 of 307 +/- 6 microM. These results provide evidence for the presence of essential sulfhydryl (possibly cysteine), and basic amino acid (possibly lysine and arginine) residues associated with the normal functioning of the KATP channel. Furthermore, we believe that the sulfhydryl group in question is situated at the internal surface of the membrane, possibly near to the channel pore.
Adenosine Triphosphate↗
Linkage of phosphoribosylpyrophosphate synthetases 1 and 2, Prps1 and Prps2, on the mouse X chromosome.
The X Chromosome (Chr) genes for phosphoribosylpyrophosphate synthetases 1 and 2, Prps1 and Prps2, were mapped on the mouse X Chr with interspecific backcrosses between C57BL/6 (B6) and M. spretus (S). Southern analysis showed that Prps1 mapped between Plp and DXWas31, a mouse X Chr region that is homologous to Xq21-24 on the human X Chr while Prps2 mapped between DXWas31 and Amg, a region that is homologous to the map position of PRPS2 on Xp22 of the human X Chr. Additionally, other restriction fragments highlighted by PRS II showed autosomal segregation. In situ hybridization and FISH analysis of metaphase chromosome spreads prepared from lymphocytes of B6 or S male mice confirmed that there were in fact two different locations on the X Chr, X F1-2 and X F2-3 for Prps1 and 2 respectively, as well as two autosomal sites for Prps-like genes.
Animals↗
Oxidative stress induced by intermittent exposure at a simulated altitude of 4000 m decreases mitochondrial superoxide dismutase content in soleus muscle of rats.
The effects were examined of 6-month intermittent hypobaric (4000 m) exposure on the antioxidant enzyme systems in soleus and tibialis muscles of rats. At the end of the 6-month experimental exposure, the six rats in both the exposed group and the control group were sacrificed. Immunoreactive mitochondrial superoxide dismutase (Mn-SOD) contents were measured as well as the activities of antioxidant enzymes [Mn-SOD, cytosolic SOD (Cu,Zn-SOD), catalase (CAT), and glutathione peroxidase (GPX)]. Thiobarbituric acid-reactive substances (TBARS) were also determined as an indicator of lipid peroxidation. The high altitude exposure resulted in a marked increase in TBARS content in soleus muscle, suggesting increased levels of oxygen free radicals. Conversely, significant decreases in both Mn-SOD content and activity in soleus muscle were noted after exposure. Such trends were not noticed in tibialis muscle. On the other hand, no significant changes in Cu,Zn-SOD, CAT, or GPX were observed in either muscle. These results suggested that the increases in lipid peroxidation were most probably a result of decreased Mn-SOD function which was more depressed in oxidative than in glycolytic muscle.
Altitude↗
Dual inhibitory mechanism of secretin action on acid secretion in totally isolated, vascularly perfused rat stomach.
BACKGROUND/AIMS: Secretin is an inhibitory hormone of gastric acid secretion. However, its inhibitory mechanism has not been well understood. Possible roles of both somatostatin and prostaglandins were investigated. METHODS: Totally isolated rat stomachs were vascularly perfused with Krebs-Ringer buffer containing 50 mumol/L isobutyl methylxanthine at 1.4 mL.min-1. Gastric lumen was perfused with 0.15 mol/L NaCl at 1.0 min.min-1. Effect of secretin in three different doses given intra-arterially on basal acid secretion and acid secretion stimulated by pentagastrin was studied. To determine roles of somatostatin and prostaglandins in the secretin-induced inhibition, an antisomatostatin serum and indomethacin were tested, and both somatostatin and prostaglandin E2 concentrations in portal venous effluent were determined by radioimmunoassay. RESULTS: Both basal- and pentagastrin-stimulated acid secretion were significantly inhibited by secretin. The inhibition was completely reversed by either indomethacin or antisomatostatin serum. Secretin significantly increased concentrations of both somatostatin and prostaglandin E2. Although indomethacin blocked the increase in prostaglandin E2, secretin-induced increase in prostaglandin E2 was not affected by antisomatostatin serum or was indomethacin influenced by somatostatin level. Finally, the inhibition by somatostatin of acid secretion was not affected by indomethacin. CONCLUSIONS: The inhibition of gastric acid secretion by secretin in rats is mediated by simultaneous releases of both somatostatin and prostaglandin E2, which independently inhibit gastric acid secretion.
Animals↗
Detection and characterization of eukaryotic enzymes that recognize oxidative DNA damage.
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Base Sequence↗
Comparison of chromosome aberrations in leiomyoma and leiomyosarcoma using FISH on archival tissues.
Fluorescence in situ hybridization (FISH) with chromosome-specific probes was used to study cytogenetic changes in five cases of leiomyosarcoma (LMS) and nine cases of uterine leiomyoma (LM). Biotinylated DNA probes for the centromeric regions of chromosomes 1, 6, 8, 9, 17, and 18, painting probes for chromosomes 1 and 22, and the cosmid probe for chromosome region 21q22.3 were used on nuclei isolated from paraffin blocks. Four of five LMS cases revealed major chromosomal aberrations, while the only case with minor clonal aberrations was subsequently found not to be a typical LMS. The most common numerical aberrations found in the LMS cases were extra copies of chromosome 8 (three of five cases), loss of chromosome 1 (three of five cases), and loss of chromosome 6 (two of five cases). One of two LMS cases studied with a chromosome 1 painting probe demonstrated translocations of chromosome 1. In contrast to LMS, only five of nine uterine LM cases had abnormal clones, and these were smaller than those in LMS. Two LM cases showed 9% tetrasomy 8 with 17 or 20% monosomy 6, and three other cases had monosomy 6 clones in 18-34% of cells. These results indicate that typical LMS is characterized by multiple chromosomal aberrations affecting most of the cells, whereas borderline LMS and LM have fewer affected chromosomes and less clonal involvement.
Adult↗
Prevalence of human papillomavirus DNA sequences in an area with very high incidence of cervical carcinoma.
To improve our understanding of the relationship and possible associations between human papillomavirus (HPV) infection and the development of cervical malignancies, the presence of multiple types of HPV DNA sequences in cervical carcinoma was determined in Chinese citizens living in two different geographical locations where the incidences of cervical carcinoma are either relatively low or extremely high. HPV DNA sequences were found in 88.5% (54 of 61) of Chinese cervical carcinoma patients living in Taiwan, where the prevalence of cervical carcinoma is 23.7 per 100,000 women. In contrast, in LueYang in Shanxi province, an area with a very high prevalence of cervical carcinoma (1,026 per 100,000 women), only 57.1% (28 of 49) of Chinese cervical carcinoma patients were found to be infected with genital HPV. This result seems to suggest that either the presence of HPV may have different implications in different populations or HPV infection may not be the only factor that determines the development of cervical carcinoma, at least in certain geographical areas. Recently acquired transient or chronic persistent HPV infection may have a different outcome with regard to cervical carcinogenesis. Alternatively, other factors, such as host determinants, may play a role in the development of cervical carcinoma.
Age Factors↗
Carbon monoxide and nitrogen dioxide exposures in indoor ice skating rinks.
Exposures to carbon monoxide (CO) and nitrogen dioxide (NO2) were determined in seven enclosed ice skating rinks and an outdoor rink. The uptake of CO was also determined by the difference in alveolar CO concentration of the non-smoking hockey players before and after games. Carbon monoxide concentrations in enclosed rinks ranged from 4 to 117 ppm and NO2 concentrations from 342 to 2729 ppb for 2 h hockey games. The CO uptakes were linearly related to the ambient CO concentrations. Alveolar CO of the hockey players increased on average by 0.53 ppm per 1 ppm CO exposure over 2 h. Considering the CO and NO2 levels currently measured in enclosed ice skating rinks, indoor air quality guidelines or standards should be established. It is recommended that 1 h maximum allowable limits of 20 ppm CO and 250 ppb NO2 be established.
Absorption↗
The UNFPA: twenty-five years and beyond.
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Family Planning Services↗
Thallium-201 uptake in keloid tissue masquerading as a pulmonary neoplasm.
Tl-201 imaging is useful in the diagnostic work-up of tumors. However, Tl-201 uptake is not specific for tumor and is also noted in other conditions. A case is described in which Tl-201 was taken up by a keloid.
Diagnosis, Differential↗