Biomedical subjects

J Lida

Publications and source records attributed to J Lida.

17 recordsLinked to original sources

PubMed2000

Wall imaging of cerebral aneurysms with a modified surface-rendering technique of spiral CT.

BACKGROUND: There has been no detailed documentation of the advantages of three-dimensional (3D) wall imaging of cerebral aneurysms. The usefulness of such endoscopic images obtained with modified spiral computed tomography angiography (CTA) was therefore examined in comparison with conventional spiral CTA and digital subtraction angiography (DSA). METHODS: Fifteen of 45 patients who underwent conventional spiral CTA in our department in the past 4 years, were further studied with a technical modification of surface-rendering reconstruction in spiral CT. Endoscopic images were obtained by regulating the lower and higher thresholds of spiral CT scans in processing. Digital subtraction angiography was also performed for 14 of the 15 patients. The 3D wall images of the cerebral aneurysms were assessed in comparison with findings from conventional CTA and DSA. FINDINGS: The true orifice of the aneurysms could be visualized with the endoscopic mode in all of the 15 cases. In paraclinoid aneurysms, particularly below the anterior clinoid process, the relationships to associated vessels and bone structures were more clearly disclosed with this mode. The endoscopic images of aneurysms with rigid clots or neighboring distended veins were not as adversely affected as conventional CTA. In 4 of the 15 the wall imaging precisely located the branches arising from the dome of aneurysms which DSA could not. INTERPRETATION: Wall imaging of complex or small cerebral aneurysms provided valuable information on their relationships to associated arteries and surrounding bony structures. The endoscopic mode, a simple modification of surface rendering, is easily available in commercial CT processing packages.

Adult↗

PubMed1994

Comparison of a PCR-based diagnostic assay for Mycoplasma pulmonis with traditional detection techniques.

Current diagnosis of infection by Mycoplasma pulmonis, an important pathogen of laboratory rodent colonies worldwide, is based on serological, histopathological and culture techniques which can be slow and unreliable. A polymerase chain reaction (PCR) assay for M. pulmonis diagnosis was compared to current diagnostic methods. This PCR based technique allows a more specific, sensitive and rapid diagnosis of M. pulmonis from various tissues by comparison with culture and histopathology.

Animals↗

PubMed1992

Analysis of the human alpha globin upstream regulatory element (HS-40) in transgenic mice.

We have analysed the effect of a 1.4 kb segment of DNA containing the upstream alpha globin regulatory element (HS-40) on human alpha globin gene expression in fetal mice and lines of transgenic mice. High levels of tissue-specific, human alpha mRNA expression were seen in all transgenic animals and in this sense expression was position independent. However, the level of human alpha mRNA expression per integrated gene copy decreased during development and was inversely related to copy number. The limitation in expression with increasing gene copy number was shown to be in cis since homozygotes for the transgene produced twice as much human alpha mRNA as hemizygotes. In many respects HS -40 appears similar to single elements within the previously described beta globin locus control region and in cross breeding experiments we have shown that HS -40 behaves in a similar manner to such elements in transgenic mice.

Animals↗

PubMed1992

A single beta-globin locus control region element (5' hypersensitive site 2) is sufficient for developmental regulation of human globin genes in transgenic mice.

The beta-globin gene complex is regulated by an upstream locus control region (LCR) which is responsible for high-level, position-independent, erythroid-cell-specific expression of the genes in the cluster. Its role in the developmental regulation of beta-like globin gene transcription remains to be established. We have examined the effect of a single LCR element, hypersensitive site 2 (HS2), on the developmental regulation of the human fetal gamma and adult beta genes in transgenic mice. In mice bearing HS2A gamma beta and HS2G gamma A gamma-117 delta beta human globin gene constructs, switching from gamma- to beta-gene expression begins at about day 13.5 of gestation and is largely completed shortly after birth. The larger construct also demonstrates a switch in G gamma- to A gamma-gene expression during the gamma-to-beta switch similar to that observed during normal human development. We conclude that HS2 alone is sufficient for developmental regulation of the human beta-globin genes.

Aging↗

PubMed1991

Effect of giving enrofloxacin in the diet to pigs experimentally infected with Actinobacillus pleuropneumoniae.

Three groups of 16 pigs were exposed individually when four weeks old to intranasal infection with 10(8.9) viable Actinobacillus pleuropneumoniae (serovar 3, strain 2/(10P2); a fourth group was kept in isolation from the others as uninfected controls. Seven days later the 62 surviving animals were killed and necropsied. The organism had caused typical, mainly subacute disease in 12 of the 16 unmedicated animals but in only two of the 16 which had had continuous access to a diet containing 150ppm of enrofloxacin from four hours before exposure to infection, and in six of the 16 given 32 ppm enrofloxacin. However, only 150 ppm enrofloxacin produced marked control of the infection in terms of reduced average severity of thoracic lesions and much reduced prevalence of the organism in the lung at necropsy, and the mean weight gain (1.55 kg) and feed conversion efficiency (2.08) of this infected group over seven days were similar to those of the unmedicated, uninfected controls (1.67 kg and 2.25). The infected but untreated group on average produced detectable antibody seven days after infection whereas in the infected and medicated groups a specific response against serovar 3 was absent.

4-Quinolones↗

PubMed1991

Molecular and functional analysis of the virus- and interferon-inducible human MxA promoter.

The virus- and interferon-inducible human MxA (IFI-78k) gene is a homologue of the murine influenza resistance gene Mx1. Three overlapping human cosmid clones covering most of the gene including its promoter region were isolated. Sequencing the 5' MxA cDNA derived by RT-PCR (reverse transcriptase-polymerase chain reaction) confirmed the most 5' putative transcriptional start site. The MxA promoter does not contain a TATA or CCAAT box but has three Interferon Stimulated Response Element (ISRE) motifs. Strong induction with type I interferons was demonstrated with a fragment containing only two ISREs in human L132 cells. This induced expression was not adversely affected by 2-aminopurine. However, the promoter showed constitutive expression in transiently or stably transfected murine LM cells.

Animals↗

PubMed1990

Studies in the in vivo expression of the influenza resistance gene Mx by in-situ hybridisation.

The inbred laboratory mouse strain A2G carries a functional, interferon type 1 inducible gene, Mx which upon expression confers specific resistance to an otherwise lethal dose of influenza virus. We investigated in vivo Mx gene expression by performing Northern hybridisation and in-situ hybridisation on A2G (Mx+) and (CBA/J x C57)F1 (Mx-) mice that were induced either with human, natural interferon; human, recombinant interferon or double stranded poly(I):(C). All 3 inducers were able to stimulate Mx expression in all organs examined in the A2G strain. However, contrary to previous reports, Mx expression was confined to a small number of cell types; the main contributor was most probably mononuclear cells. Specialised cells such as hepatocyte, nephron, ovarian follicle and seminiferous tubules did not show detectable Mx level. There was also constitutive Mx expression in the epithelia of uterus and duodenum which suggested direct gene activation independent of blood-bourne interferon.

Animals↗

PubMed1990

A major positive regulatory region located far upstream of the human alpha-globin gene locus.

We have identified a remote, tissue-specific, positive regulatory element that is of major importance in determining the level of human alpha-globin gene expression. Stable transformants containing this DNA segment linked to the alpha gene in mouse erythroleukemia cells expressed human alpha mRNA at levels that are indistinguishable from those seen in interspecific hybrids containing the human alpha genes in their normal context on chromosome 16. Furthermore, all transgenic mice containing the alpha genes linked to this region expressed alpha-globin mRNA at high levels in erythroid tissues; and in one such mouse, readily detectable levels of human alpha-globin chains could be demonstrated in the peripheral blood. There is considerable similarity in the position, structure, and function of this region upstream of the alpha-globin complex with previously described elements within the beta-globin dominant control region (DCR). This is m marked contrast to other structural and functional differences between the two gene clusters. It seems likely that these critical, positive regulatory regions might provide target sequences through which coordinate regulation of the alpha- and beta-like globin genes is achieved.

Animals↗

PubMed1990

Mechanisms of temperature acclimation in the carp: a molecular biology approach.

Most fish are unable to regulate their body temperature. Therefore their muscle power output would be expected to decline markedly with decreased environmental temperature. However, some species including carp show a remarkable ability to acclimate. The nature and significance of changes in enzymatic myosin ATPase activity and the recruitment of different muscle fiber types in relation to acclimation and environmental temperature in carp are reviewed. These changes presumably involve qualitative and quantitative changes in gene expression. To approach the problem, we have constructed a carp genomic library and isolated 28 nonoverlapping clones containing sequences of different myosin heavy chain (MHC) isoforms along with a clone containing carp actin sequences. Plasmids containing probes specific for a carp fast muscle MHC and actin RNA were constructed. Hybridization results suggest that the expression of this MHC isoform RNA is increased in warm- relative to cold-acclimated carp. These data indicate that there are different MHC isoform genes that are expressed at warm and cold environmental temperatures.

Acclimatization↗

PubMed1990

The influenza resistance murine Mx1 gene is constitutively expressed in the epithelia of the gastrointestinal, respiratory and uterine tracts.

The murine Mx1 gene confers specific resistance against influenza in the inbred A2G mice and in vitro have been shown to be inducible with type I but not type II interferons. Contrary to expectation, we found by in situ hybridisation widespread Mx1 expression along the epithelia of the gastrointestinal, uterine and respiratory tracts in uninduced A2G mice. Several lines of evidence, including further enhancement of Mx1 expression during organ culture and gnotobiotic mice analyses, indicated that this apparent constitutive epithelial Mx1 expression was a locally induced response to stimuli present in the respective lumina. This phenomenon may be a feature found in other interferon-inducible and interferon genes.

Animals↗

PubMed1990

Passive protection of piglets by monoclonal antibodies against experimental infection with Actinobacillus pleuropneumoniae.

Mouse monoclonal antibodies 11C11 (an IgG) and 4A9 (an IgM), which combine with a superficial component of cells belonging, respectively, to serovars 1 or 3 of Actinobacillus pleuropneumoniae, were given intraperitoneally 24 hours before and intranasally one hour before two-week-old, colostrum-deprived piglets were exposed by the intranasal route to 10(9) viable cells of either strain Shope 4074 (serovar 1) or 2/10 (serovar 3). Compared with control piglets given phosphate buffered saline or the heterologous monoclonal antibody, this procedure conferred substantial protection against the development of peracute or acute pleuropneumonia. Protection against the experimental disease was somewhat less in other piglets to which monoclonal antibody 4A9 was given only by the intranasal route one hour before the organism was administered than in those given the antibody intraperitoneally 24 hours beforehand, although its effect was still significantly greater than in piglets given phosphate buffered saline only. These two monoclonal antibodies consequently offer means of investigating at the molecular level the pathogenesis of the disease associated with A pleuropneumoniae and the potential value of anti-idiotypes as immunising agents.

Actinobacillus Infections↗

PubMed1990

Use of monoclonal antibodies for classifying Actinobacillus (Haemophilus) pleuropneumoniae.

The serological typing (by enzyme-linked immunosorbent assay) of 119 isolates of Actinobacillus (Haemophilus) pleuropneumoniae (representing in varying numbers the 12 serovars of this taxon) by monoclonal antibodies derived from the reference strains of serovars 1 to 5 in general correlated reasonably with the serotype previously established for these strains by conventional procedures employing polyclonal antisera. However, where there were reasonable numbers of isolates representing a given serovar to provide a decision, there was no instance where the correlation between the monoclonal and the polyclonal antibody was in complete accord. In addition, some of the differences between monoclonal and polyclonal antibody binding with some isolates suggest that the distribution of the serotype-specific antigens within the taxon may be even more complex than has previously been supposed.

Actinobacillus↗

PubMed1989

Serum protein electrophoresis in spontaneous canine hyperadrenocorticalism.

The serum protein concentrations of dogs with confirmed spontaneous hyperadrenocorticalism were determined by agarose gel electrophoresis before and during treatment with mitotane. In untreated animals a significant increase was detected in the mean concentration of total protein and the mean concentration and percentage of alpha-2 globulin. The mean concentration and percentage of albumin and gamma-globulin were significantly decreased. In animals on treatment the mean concentration of total proteins and the mean concentration and percentage of beta-2 globulin were significantly reduced.

Adrenal Cortex Diseases↗

PubMed1988

Use of a monoclonal antibody in the diagnosis of infection by Dermatophilus congolensis.

A monoclonal antibody (McAb) to Dermatophilus congolensis was produced from murine hybridoma cultures and purified by affinity chromatography. Species specificity was demonstrated using indirect immunofluorescent staining; the McAb was shown to react with 10 D congolensis isolates but not with 10 Nocardia species isolates, a Rhodococcus and a Streptomyces species isolate. The McAb was used to demonstrate D congolensis in clinical material from confirmed bovine and ovine cases and presumptive equine cases of dermatophilosis by indirect immunofluorescent staining.

Actinomycetales↗

PubMed1987

Studies of human retroviruses in relation to adult T-cell leukaemia, acquired immune deficiency syndrome, and multiple sclerosis.

Studies of adult T-cell leukaemia virus/human T-cell leukaemia/lymphotropic viruses (ATLV/HTLV-I) in Japan indicate that the virus is involved only with the development of ATL. By contrast, reports from the U.S.A. about HTLV have from time to time claimed that related HTLV are concerned not only with ATL of black persons, but also with a wide range of diseases, such as mycosis fungoides/Sezary's syndrome, T-cell hairy cell leukaemia, acquired immune deficiency syndrome (AIDS) and also multiple sclerosis. Using morphological, biological, serological and molecular hybridisation studies, we were able to confirm that the viruses implicated in the development of ATL and AIDS are distinct and that ATLV/HTLV-I is involved only in ATL, and HIV/LAV/HTLV-III only in AIDS. In vitro, ATLV/HTLV-I transformed and immortalised T-cells, while HIV/LAV/HTLV-III killed our T-cells. Failure to detect any serological cross-reaction indicates that all the structural proteins are different. Likewise, Southern blot studies failed to reveal any cross-hybridisation. Sixty patients with multiple sclerosis failed to reveal any association with ATLV/HTLV-I or with HIV/LAV/HTLV-III. Our conclusion is that ATLV/HTLV-I is involved only in ATL of Japanese and of some black persons of African origin, and that HIV/LAV/HTLV-III is associated only in AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed1987

Binding patterns of five monoclonal antibodies to Actinobacillus (Haemophilus) pleuropneumoniae.

Five monoclonal antibodies were obtained after immunising mice with superficial antigens of three strains representing serovars 1 to 3 of Actinobacillus (Haemophilus) pleuro-pneumoniae. When tested in ELISA against the standard strains representing serovars 1 to 10, the monoclonal antibody raised against the standard strain of serovar 1 reacted only with that strain. Of the three monoclonal antibodies raised against the standard strain of serovar 3, one reacted with serovars 3 and 8 only, another with serovar 7 only and the third with the strains representing serovars 7, 9 and 10. The monoclonal antibodies produced with the serovar 2 strain also reacted with a wide spectrum of strains, representing serovars 7 to 10.

Actinobacillus↗

PubMed1985

Characterization of patients with an increased susceptibility to bacterial infections and a genetic deficiency of leukocyte membrane complement receptor type 3 and the related membrane antigen LFA-1.

Three children from two unrelated families had a history of recurrent bacterial infections, and their neutrophils were shown to have deficient phagocytic and respiratory responses and possible deficiencies in chemotaxis or adherence. Their neutrophils were strikingly deficient in the ability to ingest or give a respiratory burst in response to unopsonized bakers' yeast or zymosan (Z). Tests for neutrophil and monocyte CR1 (C3b/iC3b receptor) and CR3 (iC3b receptor) demonstrated rosettes with both EC3b and EC3bi. However, EC3bi were bound only to CR1, and not to CR3, because EC3bi rosettes were inhibited completely by anti-CR1. Neutrophils, monocytes, and natural killer (NK) cells also did not fluorescence stain with monoclonal antibodies specific for the alpha-chain of CR3 (anti-Mac-1, anti-Mol, OKM1, and MN-41). Quantitation of C receptors with 125I monoclonal anti-CR1 and anti-CR3 indicated that neutrophils from each patient expressed normal amounts of CR1 per cell but less than 10% of the normal amount of CR3. Examination of neutrophils by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that a normal glycoprotein of approximately 165,000 daltons was missing. Immunoblotting of these gels indicated that the missing band was the alpha-chain of CR3. Subsequent analysis of all three patients' cells also demonstrated a deficiency of LFA-1 alpha-chain and the common beta-chain that is shared by the CR3/LFA-1/p150,95 membrane antigen family. The deficiency of LFA-1 probably explained the absent NK cell function, as normal NK cell activity is inhibited by anti-LFA-1 but not by anti-CR3. The reduced phagocytic and respiratory responses to Z were probably due to CR3 deficiency, because treatment of normal neutrophils with anti-CR3, but not anti-FLA-1, inhibits responses to Z by 80% to 90%. Ingestion of Staphylococcus epidermidis by normal neutrophils was shown to be partially inhibited by monoclonal antibodies to the alpha-chain of either CR3 or LFA-1, and monoclonal antibody to the common beta-chain inhibited ingestion by 75%. Thus, both CR3 and LFA-1 may have previously unrecognized functions as phagocyte receptors for bacteria. The absence of this type of nonimmune recognition of bacteria by these children's neutrophils may be one of the reasons for their increased susceptibility to bacterial infections.

Antigens, Surface↗