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Biomedical subjects

C Olsson

Publications and source records attributed to C Olsson.

At least 73 records · Page 4Linked to original sources
PubMed1994

Evaluation of a method for quantitative immunohistochemical analysis of cisplatin-DNA adducts in tissues from nude mice.

The reproducibility of an immunohistochemical method for visualization and quantitation of the cytotoxic drug cisplatin (CDDP) in its active position, bound to nuclear DNA, was investigated in tissues from CDDP-treated nude mice. Kidney, liver, and tumor sections were stained with a PAP technique using an antiserum elicited against CDDP-DNA adducts. The resulting brown nuclear precipitate was quantitated using a CAS 200 image analyzer. The variance components of the errors in the staining procedure and in the image analysis were estimated. The method was found to be feasible for comparisons between slides of the same type of tissue, stained in the same batch, and measured by one observer on one occasion. The method should be a valuable tool for studies of CDDP pharmacodynamics, sensitivity prediction, and the effects of interactions between CDDP and other drugs and chemomodulators.

Animals↗
PubMed1994

Distribution of PACAP (pituitary adenylate cyclase-activating polypeptide)-like and helospectin-like peptides in the teleost gut.

Pituitary adenylate cyclase-activating polypeptide (PACAP) and helospectin are two vasoactive intestinal polypeptide (VIP)-related neuropeptides that have recently been demonstrated in the mammalian gut; the aim of this study was to reveal their occurrence and localisation in the gastrointestinal tract, swimbladder, urinary bladder and the vagal innervation of the gut of teleosts, using immunohistochemical methods on whole-mounts and sections of these tissues from the Atlantic cod, Gadus morhua and the rainbow trout, Oncorhynchus mykiss. Both PACAP-like and helospectin-like peptides were present in the gut wall of the two species. Immunoreactive nerve fibres were found in all layers but were most frequent in the myenteric plexus and along the circular muscle fibres. Immunoreactivity was also demonstrated in nerves innervating the swimbladder wall, the urinary bladder and blood vessels to the gut. Immunoreactive nerve cell bodies were found in the myenteric plexus of the gut and in the muscularis mucosae of the swimbladder. In the vagus nerve, non-immunoreactive nerve cells were surrounded by PACAP-immunoreactive fibres. Double staining revealed the coexistence of PACAP-like and helospectin-like peptides with VIP in all visualized nerve fibres and in some endocrine cells. It is concluded that PACAP-like and helospectin-like peptides coexist with VIP in nerves innervating the gut of two teleost species. The distribution suggests that both PACAP and helospectin, like VIP, are involved in the control of gut motility and secretion.

Amino Acid Sequence↗
PubMed1994

A method for 2D reconstruction of intracellularly labeled neurons from sequential sections.

A technique for 2D reconstruction of intracellularly labeled neurons from sequential sections is described. The system consists of a Charged Coupled Device-camera mounted on a microscope, a videomixer and a IBM-compatible PC with a framegrabber. The neurons (interneurons from the spinal cord of the cat) were labeled iontophoretically by horshradish peroxidase and subsequently cut in 60 microns sections. The sections were aligned using the video mixer by fitting the cut dendrites and axon from one section with their counterparts in the following section. The images were then digitized in the PC where they were fused to create a superimposed picture of the aligned parts of the neuron; a 2D reconstruction was created.

Animals↗
PubMed1994

Enhancement of thrombolysis by ultrasound.

Drug-induced early reperfusion in acute myocardial infarction reduces myocardial damage and decreases mortality. A further beneficial effect may be achieved if the time from start of thrombolytic treatment to reperfusion, on average 45 min, can be shortened. With this purpose in mind, we have analysed the effect of ultrasound on the reperfusion time in an experimental model in vitro. A cylindrical fibrin thrombus with a 2 mm diameter and a 20 microL volume was made by thrombin activation of a pure 0.5% fibrinogen solution in a soft silicone tube. The tube was placed in a low pressure perfusion system and maintained at 37 degrees C. The thrombi were then exposed to hydrostatic loading with a streptokinase concentration of 5000 units/mL. Reperfusion times (RT) were measured from time of Streptokinase exposure to fluid passage, identified by the photoelectric technique. RT increased significantly with increasing thrombus age (r = 0.92, p < 0.05) and was 34-45 min (95% confidence limits) at a thrombus age of 1 h and 102-122 min at a thrombus age of 2 h. RT was unaffected by temperatures between 33 and 45 degrees C but increased with higher temperatures. All investigations of ultrasound effects were performed with 1 h old thrombi and at 37 degrees C. RT decreased by 49% (p < 0.01) as an effect of exposure to 1 MHz ultrasound at 1 W/cm2 SATA. Intermittent ultrasound exposure for 10 microseconds/ms with the same intensity and frequency shortened RT by 54% (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Circulation↗
PubMed1993

Prostatic cancer.

Explore the source record for details and available documents.

Adenocarcinoma↗
PubMed1993

Generation of x rays for medical imaging by high-power lasers: preliminary results.

PURPOSE: To evaluate the use of x-ray imaging performed with a high-power laser system in biologic and medical studies. MATERIALS AND METHODS: A compact terawatt laser system based on chirped pulse amplification in titanium-doped sapphire was used. X rays were generated by irradiating a high-atomic-number target (tantalum). RESULTS: When photons with an energy below 10 keV were removed with use of 3 mm of aluminum, the half-value layer in aluminum for the remaining x rays was approximately 10 mm. The x-ray source allowed performance of biologic magnification radiography. Star-pattern tests indicated an equivalent focal spot size of less than 60 microns. Exposures of a single pulse could be obtained. The duration of a single x-ray pulse was estimated to be of the order of picoseconds. CONCLUSION: With use of subpicosecond laser pulses, x-ray generation can occur with a smaller equivalent focal spot size than with conventional x-ray sources.

Aluminum↗
PubMed1993

1.5-cm renal mass followed for 2 years without radiographic change.

An incidentally discovered 1.5 cm renal mass was followed by serial CT scans for a period of 2 years. The mass showed no signs of growth or change during this period. The patient underwent radical nephrectomy with pathology positive for renal cell carcinoma. The evaluation of small renal masses is reviewed.

Carcinoma, Renal Cell↗
PubMed1992

Interleukin (IL1 to IL7) gene expression in fetal liver and bone marrow stromal clones: cytokine-mediated positive and negative regulation.

Mouse bone marrow and fetal liver stromal clones have been analyzed for their cytokine mRNA expression. The reverse transcriptase polymerase chain reaction (RT-PCR) has allowed us to detect interleukin (IL) mRNA levels, even if synthesized at levels not detectable by Northern blot analysis. We found that stromal cells possess the potential to constitutively express a much larger number of interleukins than previously described. The three stromal clones analyzed here expressed mRNA for IL3 and IL2, in addition to mRNA for IL1, IL4, IL6, and IL7. None of the stromal clones synthesized IL5 mRNA. Cytokine mRNA synthesis by stromal cells was found to be subjected to negative and positive regulation by interleukins. IL2, IL3, IL6, and IL7 gene expression was much more sensitive to cytokine regulation than that of IL1 and IL4.

Animals↗
PubMed1991

Structure of the T cell antigen receptor (TCR): two CD3 epsilon subunits in a functional TCR/CD3 complex.

Transgenic mice carrying and expressing the human CD3 epsilon gene incorporate the corresponding protein product into T cell receptor (TCR)/CD3 complexes on thymocyte and T cell surfaces. The chimeric antigen receptors allow normal T cell development and selection of repertoires in vivo and are able to transduce activation signals in vitro. We have exploited the ability to distinguish mouse (m) and human (h)CD3 epsilon chains to analyze the stoichiometry of CD3 epsilon in transgenic mouse TCRs. Immunoprecipitation and fluorescence resonance energy transfer experiments demonstrate that such TCRs can contain both h- and mCD3 epsilon chains, implying that more than one CD3 epsilon subunit occurs per TCR. Antigen comodulation studies are consistent with a stochastic use of h- or mCD3 epsilon during receptor assembly, and further suggest a structure for the TCR/CD3 complex with two CD3 epsilon chains. The determination of CD3 epsilon subunit stoichiometry, together with existing biochemical data, allows the generation of a minimal model for the structure of the TCR and illustrates the potential value of the transgenic approach to the analysis of complex receptors.

Animals↗
PubMed1989

Production and secretion of recombinant soluble CD3 polypeptides by myeloma-derived transfectant clones.

Soluble forms of three human CD3 proteins have been produced by recombinant DNA techniques. The extracellular domain of CD3-gamma, -delta or -epsilon has been linked to the constant region of mouse immunoglobulin kappa light chain to form gamma-kappa, delta-kappa and epsilon-kappa chimaeric proteins. These are secreted by mouse myeloma-derived transfectant cell lines and are immunoprecipitable by CD3- or kappa-specific polyclonal antisera. Yields of 100-500 micrograms secreted recombinant proteins per litre of culture medium were obtained, which could be purified by anti-kappa affinity chromatography. The production of soluble CD3 illustrates the applicability of this technology to a loosely associated protein complex.

Antigens, Differentiation↗
PubMed1989

The majority of human CD3 epitopes are conferred by the epsilon chain.

Transgenic mouse T cells expressing the human CD3 epsilon chain bind the majority (29/36) of monoclonal antibodies (mAbs) specific for human CD3. A proportion of these mAbs are also able to recognize isolated CD3 epsilon in a soluble, recombinant form. Thus, CD3 epsilon can confer most CD3 epitopes on the TCR--CD3 complex, but many determinants may require assembly of the complex for their formation. A number of mAbs did not recognize epsilon-transgenic T cells and probably need other CD3 subunits for binding. CD3-specific mAbs from each of the three groups defined here, as well as mAbs directed against the TCR alpha beta heterodimer, are all able to activate T cells. Therefore mAb attachment at several different sites on the TCR--CD3 complex can give rise to activation signals. This suggests that the cross-linking function of mitogenic antibodies may be their most significant property, rather than the perturbation of a particular 'functional epitope'.

Animals↗
PubMed1988

Organization of the human CD3 locus on chromosome 11.

Three CD3 genes, gamma, delta, epsilon, map to human chromosome 11 band q23. A 75-kb region of 11q23 containing all three genes has been characterized by field inversion gel electrophoresis and molecular cloning. The CD3 genes lie within a stretch of 50 kb of DNA, orientated 3'-CD3 gamma-5': 5'-CD3 delta-3': 3'-CD3 epsilon-5'. Only 1.6 kb separate the CD3 gamma and CD3 delta genes, while the CD3 delta and CD3 epsilon genes are approximately 22 kb apart. CD3 gene expression is one of the first events during the maturation of the thymocyte, and therefore the clustering of CD3 genes may define a chromatin domain which is activated early in T cell development.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1987

Quantitative morphometry measurements of transitional cell bladder cancer nuclei as indicator of tumor aggression.

Superficial transitional cell carcinomas of the urinary bladder in 30 patients were studied by quantitative morphometry of the initial and subsequent tumor occurrences. Nuclear histograms were constructed and demonstrated narrow base and single modal peak in 9 of 10 patients not exhibiting tumor recurrence or invasion. In contrast, broad-based multimodal nuclear histograms were present in 15 of 20 patients in whom tumor invasion of carcinoma in situ subsequently developed. Nuclear histograms may provide an accurate means of determining invasive/recurrence potential of transitional cell carcinoma.

Carcinoma, Transitional Cell↗
PubMed1986

Effect of immediate postoperative nutritional support on length of hospitalization.

This study is a retrospective review of the effect of nutritional support on duration of hospitalization in patients undergoing radical cystectomy. Thirty-five patients were randomly assigned to receive either 5% dextrose (D5W) solution plus electrolytes or total parenteral nutrition (TPN) following operation. The assigned nutritional regimen was continued for 1 week after operation until oral intake resumed. If the patients receiving D5W remained incapable of oral intake after 1 week, TPN was instituted. The group receiving immediate postoperative TPN had a median duration of hospitalization of 17 days, while the median duration for the group receiving 5% dextrose solution was 24 days. All other patient characteristics, such as age, sex, stage/grade of tumor, and extent of preoperative radiotherapy, were similar in the two groups. These results demonstrate that immediate postoperative institution of nutritional support reduced hospitalization time following radical cystectomy. This indicates that the routine use of 5% dextrose as postoperative nutrition should be reevaluated.

Aged↗
PubMed1986

The use of the Boari-flap and psoas-bladder hitch technique in the repair of a high ureteric lesion. A case report.

Combining the bladder-psoas hitch Boari-flap technique makes it possible to replace the entire ureter. The operation was used successfully in one patient with an extensive proximal ureter lesion. This method can be used in patients with reduced renal function, since the continuity of the urinary tract is preserved; it requires a normal bladder wall and bladder capacity exceeding 400 ml.

Female↗
PubMed1985

Stimulation of initial neural crest cell migration in the axolotl embryo by tissue grafts and extracellular matrix transplanted on microcarriers.

The present experiments were designed to test whether the onset of neural crest cell migration in the embryonic axolotl trunk is stimulated by surrounding tissues and their associated extracellular matrix (ECM). Tissue grafts, or embryonic ECM adsorbed in vivo onto inert "microcarriers" prepared from Nuclepore filters, were placed close to the premigratory neural crest cells, and the embryos were then incubated to a specific stage. The experiments were evaluated with light microscopy, SEM, and TEM. It was found that grafts from the dorsal epidermis were especially effective in locally stimulating initial neural crest cell migration in the region under the graft. The microcarrier experiments showed that the subepidermal ECM alone could initiate neural crest cell migration, implying that the ECM of the epidermal grafts was the stimulating factor. These results indicate that the premigratory neural crest cells along the trunk have migratory capability but that they need to be triggered from the environment, probably from the surrounding ECM, to start migration. It is proposed that ECM, as substrate for cell locomotion, initiates and regulates the onset of neural crest cell migration.

Ambystoma↗