PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-22 (22)
 

Clipboard (0)
None
Journals
more »
Year of Publication
Document Types
1.  Effect of recombinant soluble CD4 on human peripheral blood lymphocyte responses in vitro. 
Journal of Clinical Investigation  1988;82(6):2176-2180.
We have previously demonstrated that recombinant soluble CD4 protein (rsT4) blocks both HIV-1 infection of CD4 bearing lymphocytes and syncytium formation in vitro. (Recombinant soluble CD4 is designated by rsT4). Hence, we suggested the use of rsT4 in therapy for AIDS or the prevention of HIV-1 infection in individuals with a known risk of exposure. However, concerns arose that rsT4 might be immunosuppressive because of its implicated role in the enhancement of certain lymphocyte activation events through its engagement of MHC class II molecules on target cells. We therefore assessed the effect of recombinant soluble CD4 upon a number of functional and activation parameters of lymphocytes, including cellular proliferation, IL-2 secretion, and cytolytic capability, after antigenic or mitogenic stimulation. We report here that rsT4, at 60-fold over the concentration needed to block acute HIV-1 infection in vitro, does not significantly inhibit the activation of human peripheral blood lymphocytes by either PHA, tetanus toxoid or allogeneic cells. These results indicate that rsT4 will potentially exert minimal immunosuppressive effects in vivo, thus supporting the feasibility of clinical trials of rsT4 in the treatment or prevention of AIDS. In addition, the implications of these results for the interactions between CD4 and MHC class II molecules during lymphocyte activation are discussed.
PMCID: PMC442804  PMID: 3264292
2.  Physiology of the retrocalcaneal bursa. 
Annals of the Rheumatic Diseases  1988;47(11):910-912.
To clarify the function of the retrocalcaneal bursa the hindfoot was studied by magnetic resonance imaging at various positions of the ankle joint. In normal individuals a tongue-like extension of the retromalleolar fat pad entered the bursa during plantar flexion as the angle between Achilles tendon and calcaneus widened. The reverse occurred in dorsiflexion. In contrast, in a patient with spondyloarthritis and retrocalcaneal bursitis excessive cavitary fluid prevented the intrusion of the fat pad. The sliding motion of the fat pad in and out of the bursa during ankle motion allows a more caudal, advantageous insertion of the Achilles tendon into the calcaneus.
Images
PMCID: PMC1003630  PMID: 3207374
3.  Hepatic abscess and cystic fibrosis. 
Postgraduate Medical Journal  1988;64(756):814-817.
Extrapulmonary infection is rare in cystic fibrosis. We describe two adult patients with cystic fibrosis whose course was complicated by the development of liver abscesses. The possible aetiology of these abscesses is discussed and the diagnosis, treatment and prognosis of pyogenic hepatic abscess is briefly reviewed.
Images
PMCID: PMC2429001  PMID: 3255926
4.  Construction and application of plasmids containing bidirectional promoters of vaccinia virus. 
Journal of Virology  1988;62(12):4832-4834.
A bidirectional expression vector containing both the 11KD late promoter (p11) and the presumptive 25KD early promoter (p25) was constructed. These bidirectional vectors have been applied to the expression of hepatitis B surface antigen by using one of the promoters for beta-galactosidase as the marker gene and the other one for hepatitis B surface antigen as the target gene.
PMCID: PMC253610  PMID: 2846896
5.  Cytochrome components of nitrate- and sulfate-respiring Desulfovibrio desulfuricans ATCC 27774. 
Journal of Bacteriology  1988;170(12):5545-5551.
Three multiheme c-type cytochromes--the tetraheme cytochrome c3 (molecular weight [MW] 13,500), a dodecaheme cytochrome c (MW 40,800), and a "split-Soret" cytochrome c (MW 51,540), which is a dimer with 2 hemes per subunit (MW 26,300)--were isolated from the soluble fraction of Desulfovibrio desulfuricans (ATCC 27774) grown under nitrate- or sulfate-respiring conditions. Two of them, the dodecaheme and the split-Soret cytochromes, showed no similarities to any of the c-type cytochromes isolated from other sulfate-reducing bacteria, while the tetraheme cytochrome c3 appeared to be analogous to the cytochrome c3 found in other sulfate-reducing bacteria. For all three multiheme c-type cytochromes isolated, the homologous proteins from nitrate- and sulfate-grown cells were indistinguishable in amino acid composition, physical properties, and spectroscopic characteristics. It therefore appears that the same c-type cytochrome components are present when D. desulfuricans ATCC 27774 cells are grown under either condition. This is in contrast to the considerable difference found in Pseudomonas perfectomarina (Liu et al., J. Bacteriol. 154:278-286, 1983), a marine denitrifier, when the cells are grown on nitrate or oxygen as the terminal electron acceptor. In addition, two spectroscopy methods capable of revealing minute structural variations in proteins provided identical information about the tetraheme cytochrome c3 from nitrate-grown and sulfate-grown cells.
PMCID: PMC211649  PMID: 2848008
6.  Red cell hypoplasia, thrombocytosis, and leucocytosis: myelodysplastic and proliferative syndrome. 
Journal of Clinical Pathology  1988;41(11):1168-1170.
Three patients with chronic red cell aplasia also showed thrombocytosis or granulocytosis, or both. All had morphological evidence of myelodysplasia on examination of bone marrow aspirate but none had a detectable chromosomal abnormality. These patients seem to provide evidence of a separate entity within the spectrum of myelodysplastic and myeloproliferative disease.
PMCID: PMC1141724  PMID: 3145289
7.  A silencer element from the alpha-globin gene inhibits expression of beta-like genes. 
Molecular and Cellular Biology  1988;8(11):5047-5051.
We have studied the cis and trans interactions of the alpha- and beta-globin genes in a transient expression system. We found that the alpha-globin gene inhibited beta-globin expression in cis but not in trans. The silencer element responsible for this inhibition was localized to a 259-base-pair fragment at the 5' end of the alpha-globin gene.
Images
PMCID: PMC365600  PMID: 2850473
8.  The reason for loss of agglutinability of Pseudomonas aeruginosa cells heated to 60 degrees C. 
Journal of Clinical Microbiology  1988;26(10):2180-2181.
The loss of agglutinability of live Pseudomonas aeruginosa cells by mild heating to 60 to 80 degrees C is due to denaturation of surface slime, which can no longer combine with antibodies but is still attached to the cell surface and thus prevents access of antibodies to the cell wall. Prolonged boiling or autoclaving would not only denature the slime but also detach it from cell surface and thus make the cells accessible to antibodies directed to cell wall antigens. Heated cells are, however, no longer agglutinable by antibodies directed to slime antigens. After prolonged boiling or autoclaving, a large amount of polysaccharides appeared in the supernatant, and concomitantly, total cell volume as measured by turbidity of the cell suspension was significantly reduced.
PMCID: PMC266841  PMID: 3141461
9.  Effects of sodium cromoglycate and nedocromil sodium on histamine secretion from human lung mast cells. 
Thorax  1988;43(10):756-761.
Sodium cromoglycate and nedocromil sodium produced a dose dependent inhibition of histamine secretion from human pulmonary mast cells obtained by bronchoalveolar lavage and by enzymatic dissociation of lung parenchyma. Both compounds were significantly more active against the lavage cells than against the dispersed lung cells, and nedocromil sodium was an order of magnitude more effective than sodium cromoglycate against both cell types. Tachyphylaxis was observed with the parenchymal cells but not with the lavage cells. Nedocromil sodium and sodium cromoglycate also inhibited histamine release from the lavage cells of patients with sarcoidosis and extrinsic asthma.
PMCID: PMC461499  PMID: 2462755
10.  Method for in vitro conversion of rough strains of Pseudomonas aeruginosa to smooth strains. 
Rough and serologically nontypable strains of Pseudomonas aeruginosa were found to become smooth and typable in vitro when they were maintained in a soft agar containing 0.5% peptone in distilled water and the dried out agar cultures were replenished monthly with a similar peptone solution in distilled water. After about a year, all of the nine rough strains of P. aeruginosa maintained this way became smooth and typable, and their pigmentations also changed significantly. Some melanogenic strains became fluorescine producers, and some weakly chromogenic strains became strong producers of fluorescine and pyocyanin.
PMCID: PMC266732  PMID: 3141469
11.  Simple genetic method to identify viridans group streptococci by colorimetric dot hybridization and fluorometric hybridization in microdilution wells. 
Journal of Clinical Microbiology  1988;26(9):1708-1713.
Simple dot hybridization and fluorometric hybridization methods in microdilution wells were designed and established for rapid and routine genetic identification of viridans group streptococci. Reference DNA extracted from each strain of 24 reference Streptococcus species was fixed both on a nitrocellulose filter and in a microdilution well. A 1-ml portion of the bacterial suspension which matched the turbidity of McFarland no. 2 standard was prepared when a streptococcal strain was isolated. It was lysed with achromopeptidase, and the DNA was quickly labeled with photobiotin under a sunlamp for 15 min. Dot hybridization and fluorometric hybridization were then carried out between the labeled DNA of the unknown organism and 24 unlabeled reference DNAs. Hybridized fragments on a nitrocellulose filter were detected by using alkaline-phosphatase-conjugated streptavidin and analyzed with a color graphic analyzer. Hybridized fragments in microdilution wells were quantitatively detected by using an enzyme, streptavidin-conjugated beta-D-galactosidase, and a fluorogenic substrate, 4-methylumbelliferyl-beta-D-galactoside. Strains belonging to each genetically distinct species could be identified by this dot blot hybridization test. However, some clinical strains cross-hybridized with two or more reference species, and then they were difficult to differentiate by dot blot hybridization. In such a case, fluorometric identification provided reliable results because the fluorometric method was more quantitative than dot blot identification. By these methods, it was possible to determine species assignment within the viridans group.
Images
PMCID: PMC266701  PMID: 3183018
12.  Intact motility as a Salmonella typhi invasion-related factor. 
Infection and Immunity  1988;56(8):1967-1973.
Invasiveness of Salmonella typhi was investigated. At first, we introduced Tn5 into the chromosome of a wild-type S. typhi strain, GIFU 10007, and screened the independent Tn5 insertion mutants for noninvasive (Inv-) strains. During the first half of this work, we obtained 4 Inv- strains from 1,338 independent Tn5 mutants. The four were either nonflagellate (Fla-), nonmotile (Mot-), or nonchemotactic (Che-). We then isolated more Fla-, Mot-, or Che- mutants and examined the invasiveness of these mutants. Sixty-three spontaneous or Tn5 insertion motility mutants, i.e., Fla-, Mot-, or Che-, were independently isolated from the wild-type strain GIFU 10007; all of them were noninvasive. Motile revertants isolated from some of these mutants showed the same invasiveness as the parent strain. P22-mediated transductional crosses were carried out between some of the motility mutants (as the recipients) and the Fla- reference strains of S. typhimurium with known deletion sites on the genome (as the donors). The mutational sites of the S. typhi mutants were assigned almost evenly to the three flagellar gene regions (regions I, II, and III) of S. typhimurium. The invasiveness of the motile recombinants obtained from the transduction assays was examined. The restoration of intact motility resulted in the restoration of invasiveness. Thus, we conclude that intact motility is an invasion-related factor of S. typhi. The relationship of Vi antigen to the invasiveness of S. typhi was also studied. Vi-negative mutants with intact motility remained invasive, whereas all 63 Inv- spontaneous or Tn5 mutants were Vi positive. Therefore, Vi antigen was not related to the invasiveness of S. typhi.
Images
PMCID: PMC259509  PMID: 2840399
13.  Effects of pyrethroid insecticides on subjects engaged in packaging pyrethroids. 
He, F | Sun, J | Han, K | Wu, Y | Yao, P | Wang, S | Liu, L
A health survey was conducted on 199 workers engaged in dividing and packaging pyrethroids. The subjects were exposed to fenvalerate at 0.012-0.055 mg/m3 and deltamethrin at 0.005-0.012 mg/m3 in the air with simultaneous skin contact for 0.5-4.5 months. Burning sensations and tightness or numbness on the face appeared in two thirds of the subjects and one third had sniffs and sneezes. Abnormal facial sensations, dizziness, fatigue, and miliary red papules on the skin were more evident in summer than in winter. Neither abnormalities in other organs or systems nor symptoms or signs of acute pyrethroid poisoning were found by interviews, examinations, and laboratory tests. There was no significant difference in plasma levels of NA, cAMP, and cGMP between the examined subjects and the control group. The urine concentration of fenvalerate in the study group ranged from 1.02 to 18.6 micrograms/l; deltamethrin in the urine was present in trace amounts.
PMCID: PMC1009649  PMID: 3415921
14.  Angiotensin II stimulation of hydrogen ion secretion in the rat early proximal tubule. Modes of action, mechanism, and kinetics. 
Journal of Clinical Investigation  1988;82(2):601-607.
Physiologic concentrations of angiotensin II stimulate sodium transport by intestinal and renal early (S1) and late (S2) proximal tubule epithelial cells. We recently found that hydrogen ion secretion, which effects sodium bicarbonate absorption, was a transport function preferentially and potently increased by angiotensin II in S1 cells. S1 cells are normally responsible for half of the total renal hydrogen ion secretion. The mechanism by which angiotensin II regulates intestinal sodium transport is by potentiating sympathetic nerve activity and norepinephrine release. Direct control of hydrogen ion secretion by angiotensin II via receptors on epithelial cells has not been previously demonstrated. We now report that stimulation of in vivo hydrogen ion secretion in the rat early proximal tubule by angiotensin II was not mediated via change in nerve activity. Rather, enhanced hydrogen ion secretion by angiotensin II correlated with increased angiotensin II receptor density on epithelial cells in the early compared to late microdissected proximal tubule. Basolateral as well as luminal angiotensin II stimulated bicarbonate absorption. Angiotensin II reduced bicarbonate permeability and caused alteration in the apparent substrate affinity, but not maximal capacity, of the proximal hydrogen ion secretory system involving the Na+/H+ antiporter.
Images
PMCID: PMC303554  PMID: 2841357
15.  Mechanism of action of Escherichia coli heat stable enterotoxin in a human colonic cell line. 
Journal of Clinical Investigation  1988;82(2):514-523.
Escherichia coli heat stable enterotoxin (STa) caused Cl- secretion across T84 cell monolayers in a dose-dependent manner only when applied to the apical membrane surface and not when applied to the basolateral surface. Measurement of cAMP, cGMP, and free cytosolic Ca2+ in response to STa suggested that cGMP alone mediated the Cl- secretory response. Studies utilizing blockers of the Na+,K+-ATPase pump, a Na+,K+,Cl- cotransport system, a K+ channel, and a Cl- channel suggest that all of them participate in the Cl- secretory process induced by STa. The results suggest that the Cl- secretory response induced by STa is mediated by cGMP after the enterotoxin binds to its receptor on the apical membrane. The enterotoxin, by increasing cGMP, opens a K+ channel on the basolateral membrane as well as a Cl- channel on the apical membrane. The activation of these ion exit mechanisms, together with activations of the Na+,K+,Cl- cotransporter and the Na+,K+-ATPase pump drives Cl- exit through the Cl- channel on the apical membrane.
PMCID: PMC303542  PMID: 2457034
16.  A case of IgD myeloma presenting as diffuse osteosclerosis. 
Journal of Clinical Pathology  1988;41(5):486-489.
A case of IgD myeloma accompanied by diffuse osteosclerosis is reported. A trephine biopsy specimen showed only reticulin fibrosis, but histomorphometric analysis of a full thickness transiliac bone biopsy specimen showed increased trabecular bone mass, with no local deposit of tumour. An excess of bone surfaces were covered by osteoid seams, all of which showed active mineralisation, indicating a relative increase in osteoblastic activity; osteoclasis seemed to be unaffected. It is suggested that the cause of the generalised osteosclerosis might be production of an osteoblast stimulating factor by the myeloma cells.
Images
PMCID: PMC1141497  PMID: 3384980
17.  Differential expression of individual members of the histone multigene family due to sequences in the 5' and 3' regions of the genes. 
Molecular and Cellular Biology  1988;8(5):1887-1895.
Histone proteins are encoded by a multigene family. The H3.2(614) and H2a(614) genes are present as single copies which are expressed at high levels, accounting for 30 to 40% of the H3 and H2a mRNAs, respectively, in different types of mouse cells. The other genes which have been isolated each contribute only a very small amount to the total type-specific mRNA pool. We demonstrate here that the differences in the level of expression of these genes are partly due to differences in their transcription rates. To investigate the sequences responsible for these differences in expression among the members of each family, we carried out DNA-mediated gene transfer experiments with both intact and chimeric histone genes. The 5' region of a highly expressed gene [H3.2(614) or H2a(614)] was attached to the 3' region of a histone gene which was expressed at low levels (H3-221 or H2a-291) and vice versa. The results show that sequences in both the 5' and 3' regions of the H3.2(614) and H2a(614) genes contribute to their high level of mRNA production by two independent mechanisms. The effect of the 3' sequences on mRNA accumulation has been narrowed to a 65-base-pair region including the 3'-terminal palindrome and downstream signal implicated in mRNA processing.
Images
PMCID: PMC363366  PMID: 3386629
18.  B-cell lymphoproliferation and lymphomagenesis are associated with clonotypic intracellular terminal regions of the Epstein-Barr virus. 
Journal of Virology  1988;62(3):962-969.
We analyzed 17 B-cell lineages cloned from two patients with infectious mononucleosis and found that different B-cell lineages exhibited notable variation in the length of the fused Epstein-Barr virus (EBV) terminal region on intracellular EBV episomes. EBV termini in different B-cell clones from the same person differed by as many as 15 to 20 reiterations of the ca. 500-base-pair terminal repeat sequence. In contrast, analysis of seven B-cell lineages cloned from a patient with a fatal, oligoclonal lymphoma revealed that three of the cell clones had the same-sized EBV terminal region. These three clones had previously been shown, by immunoglobulin gene analysis, to be metastatic daughter cells descended from a common progenitor. Similarity of the EBV terminal regions in the three daughter clones suggested that EBV infected the progenitor cell before proliferation and metastasis. Individual, EBV-infected cells from a single individual showed sufficient heterogeneity in their EBV termini to allow use of terminal fragment size as a clonal marker in studies addressing the contribution of EBV to the clonal pathogenesis of tumors with which this virus has been associated.
Images
PMCID: PMC253655  PMID: 2828691
19.  Human immune responses to major human cytomegalovirus glycoprotein complexes. 
Journal of Virology  1988;62(3):1066-1070.
Sera from both human cytomegalovirus (HCMV)-seropositive adults and infants with congenital HCMV infection recognized two major HCMV glycoprotein complexes. However, proliferative responses of peripheral blood mononuclear cells to these complexes varied among seropositive adults and were not detected in any of the infants. Thus, these glycoproteins alone may not be sufficient to develop a subviral HCMV vaccine.
Images
PMCID: PMC253669  PMID: 2828655
20.  The enhanced transfer of drug-resistant genes in NIH-3T3 cells transformed by the EJras oncogene. 
The spontaneous transfer of drug resistance genes has been shown to take place between cultured mammalian NIH-3T3 cells and occurs with a hierarchy of transfer efficiencies, transformed cells being more efficient than non-transformed cells. This experiment was accomplished by co-cultivating two NIH-3T3 sublines, each transfected by standard plasmid methods with a different drug resistance gene, subjecting the mixed population to double selection by adding both drugs to the mixed cell culture, and isolating single cells which were resistant to both drugs. The genes used were the neo gene and gpt gene which conferred resistance to the drugs G418 and mycophenolic acid, respectively. DNA analysis confirmed the presence of both resistance genes in the cells which were resistant to both drugs. The mechanism of this gene transfer was by cell fusion rather than by chromosomal DNA uptake. The efficiency of gene transfer, as indicated by the number of double-resistant colonies standardized by number of cells cultured, was much higher between two sublines of cells transformed by the EJras oncogene than between one transformed and one non-transformed subline, which in turn was higher than between two non-transformed sublines. The higher efficiency of gene transfer between the transformed cells also occurred when these cells were injected into nude mice, thus demonstrating that the same process occurred in vivo. It would appear that drug resistance genes may be transferred spontaneously in cultured mammalian cells by cell fusion, and that transformed cells have a higher efficiency of gene transfer compared to non-transformed cells.
Images
PMCID: PMC2590405  PMID: 3284209
21.  Rapid identification of bacterial genes that are lethal when cloned on multicopy plasmids. 
Journal of Bacteriology  1988;170(1):468-470.
A procedure to identify genes that are lethal when cloned on multicopy plasmids was developed. It depends on the ability of mini-Mu plasmid elements to be used for both in vivo cloning and generalized transduction of enterobacterial genes. The feasibility of this procedure was demonstrated by using the tetA gene of Tn10, which is lethal when in multiple copies in the presence of 25 micrograms of tetracycline per ml.
PMCID: PMC210670  PMID: 3275630

Results 1-22 (22)