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PubMed1982

[Current immunologic aspects of kidney transplantation].

The results of clinical kidney transplantation are mainly dependent on immunologic factors many of which are unknown or of unspecified importance. Blood transfusions have a favorable effect on graft prognosis, although our knowledge about optimal transfusion protocols and transfusion-induced mechanisms is still incomplete. The value of HLA-typing is controversial: whereas compatibility of the "classical" HLA-A,B,C antigens improves graft survival only moderately, HLA-DR typing, routinely performed for the last 3 years only, might be of greater importance. In addition, non-HLA systems, such as endothelial/monocytic antigens or the Lewis blood group system, appear to play a role in graft rejection. The individual immune reactivity a recipient to a large extent determines the fate of a graft. The multifactorial dependence of graft prognosis is discussed in this report.

Blood Group Incompatibility↗
PubMed1995

No effect of 60 Hz electromagnetic fields on MYC or beta-actin expression in human leukemic cells.

Epidemiological studies have shown weak correlations between exposure to extremely low-frequency electromagnetic fields (ELF EMFs) and the incidence of several cancers, particularly childhood leukemias, although negative studies have also been reported. These observations have prompted a broad range of in vitro cellular studies in which effects of ELF EMFs have been observed. However, no reported response has been replicated widely in independent laboratories. One potentially important response is the rapid activation of proto-oncogenes and other genes in human leukemic (HL60) cells and a wide variety of other eukaryotic cells, because of the role of these genes in cell proliferation. We describe quantitative Northern analysis of MYC and beta-actin mRNAs from HL60 cells exposed to fields under conditions very similar to those reported previously to activate these genes, namely 60 Hz sinusoidal magnetic fields of 0.57, 5.7 or 57 microT for 20 min. In addition we have used a new design of field-exposure system and introduced a number of other modifications to the protocol to optimize any response. We have also developed a novel method providing enhanced accuracy for the quantitative measurement of mRNA. No significant effect of ELF EMFs on gene expression was observed using any of these systems and analytical methods.

Actins↗
PubMed1995

Cryosurgical ablation for prostate cancer: a current review.

The available data on the efficacy of cryosurgery are still too immature to recommend this as a comparable option to radical surgery in the younger patient (< 72 years old) with organ-confined disease and at least a 10- to 15-year life expectancy. The available 3-month and 1-year positive biopsy figures of 10% to 20% are inversely comparable to the 10-year 80% to 90% disease-free survivals in contemporary radical prostatectomy series. While we wait for survival data to mature, it is unlikely that 10% to 20% local recurrence rates will translate into 80% to 90% disease-free survival rates. Only the data from the Crittendon Hospital group, which reports positive biopsies at 1 year of 3% to 4%, deserves special attention. Their protocol of optimal presurgical androgen ablation, use of thermosensors, and use of 2 to 3 freeze cycles may direct the way to a better cryosurgical technique. Conversely, the 2 to 8 months of presurgical androgen deprivation may just be prolonging the appearance of cryo-resistant cells. Regarding clinical stage C disease, the data looks promising with similar results as in organ-confined disease with a 10% to 20% positive biopsy rate at 3 months. One has to be cautious about what is really a stage C lesion, and comparison of preoperative PSA values enhance the comparisons between series. Overall, if the 1-year local recurrence rate does not exceed 30%, recommending cryosurgery as a viable option seems reasonable.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Skeletal muscle for cardiac assist.

Although current efforts at cardiomyoplasty have not produced the anticipated clear-cut benefits in cardiac function, replicable improvements in subjective function have resulted. Efforts at optimizing conditioning protocols, skeletal muscle strength, and timing of skeletal muscle assist devices should provide further improvements in cardiomyoplasty. Further work with alternative ways of configuring skeletal muscle for cardiac assist is extremely promising. SMVs, in particular, offer potential to augment cardiac function directly or indirectly powering pumps. Work in all these areas is in early stages, but the future is bright.

Animals↗
PubMed1976

Randomized clinical trial of antithymocyte globulin in cadaver renal allograft recipients: importance of T cell monitoring.

Despite incontrovertable evidence demonstrating the unique immunosuppressive capabilities of antihymocyte globulin (ATG) in animals, its value in clinical transplantation has remained inconclusive. A multicenter, prospective study was undertaken in an attempt to determine this value. Cadaver renal allograft recipients were randomized into two treatment groups: prednisone and azathioprine only, or prednisone, azathioprine, and ATG. Four to 36 month follow-up of our first 50 recipients, supported by results in over 200 patients from other centers, permits the following observations. (1) Allograft survival can be improved by nearly 20 percent in recipients treated with active ATG preparations. (2) Presently available assays performed in vitro and on subhuman primate allograft survival, though capable of excluding inactive preparations, cannot quantitate precisely the immunosuppressive capacity of active batches of ATG. (3) Monitoring circulating T cell levels in patients receiving ATG appears to offer the best means of defining immunosuppressive potency and the variation in response to the agent among identically treated individuals. It is concluded that ATG therapy can be beneficial in renal transplantation; but monitoring of recipients' T cell level is desirable during therapy to determine the dosage required. Furthermore, the optimal immunosuppressive protocol can be approximated by modifying the regimen according to individual variations in response, thus limiting the infectious complications of excessive immunosuppression.

Adolescent↗
PubMedDate not supplied

Development and evaluation of a non-isotopically labeled DNA probe for the diagnosis of infectious laryngotracheitis.

A digoxigenin-labeled cloned infectious laryngotracheitis virus (ILTV) DNA fragment was evaluated as a nonradioactive alternative probe in the diagnosis of infectious laryngotracheitis. The dot-blot hybridization protocol was optimized and was capable of detecting 40 pg of purified ILTV DNA and as few as 50 ILTV-infected chicken embryo liver cells. The utility of this approach for diagnostic use was evaluated through four ILTV inoculation trials using a mild field isolate, a virulent challenge strain, a tissue-culture-origin vaccine, and an egg-origin vaccine. Birds were examined for clinical signs of ILT, and conjunctival and pharyngeal swabs from inoculated and sentinel birds were tested for ILTV by the digoxigenin-labeled probe and by virus isolation. In general, higher numbers of ILTV-positive samples were detected by both assays from conjunctival swabs. For the non-vaccine strains, detection by dot-blot hybridization was equivalent to that for virus isolation. However, for the two vaccine strains, there was some lack of correlation between the dot-blot results and the virus-isolation results. The kappa values between virus-isolation results and dot-blot results for the tissue-culture-origin vaccine, egg-origin vaccine, Ont 1598 field isolate, and virulent strain were 0.00, 0.16, 0.39, and 0.24, respectively, for pharyngeal samples and 0.19, 0.29, 0.58, and 0.48, respectively, for conjunctival samples.

Animals↗
PubMed1994

Boron neutron capture therapy: boron biodistribution and pharmacokinetics of Na2B12H11SH in patients with glioblastoma.

Data on biodistribution and pharmacokinetics of Na2B12H11SH are few and lack in standardization. This study comprises a uniform series of 10 patients with glioblastoma administered Na2B12H11SH i.v. 24 h before surgery at a dose level used in earlier therapeutical trials (75 mg/kg body weight). Boron concentrations in tumor, normal brain, peritumoral edematous brain, blood, and urine were determined by inductively coupled plasma-atomic emission spectroscopy 24 h after Na2B12H11SH administration; boron uptake in tumor (mean, 12.2 micrograms/g) was sufficiently selective compared to concentrations in normal and edematous brain (1.2 and 2.3 micrograms/g, respectively). Mean concentration ratio of tumor:blood was slightly above unity. Boron concentration in blood decreased according to an open two-compartment model, mean excretion in urine over 24 h was 81.9%. The only side effect was an inconstant facial flush. Among efforts aiming at an optimized treatment protocol a dose escalation study seems to be justified.

Borohydrides↗
PubMedDate not supplied

The intracellular distribution of vinculin and alpha 2 integrin in epithelial cells and chondrocytes.

The purpose of this study was to demonstrate the presence of vinculin and alpha 2 integrin in chondrocytes in situ and epithelial cells. We also determined that the appropriate fixation and extraction protocols for immunohistochemistry and laser scanning confocal microscopy for an integral membrane protein and an actin-associated protein in cultured cells and whole tissue was different. Cultured epithelial cells, whole mount human cornea and avian cartilage were fixed and prepared using a number of standard procedures used for indirect fluorescence immunohistochemistry. The distribution of vinculin was cell-type and fixation-specific. Chondrocytes and cultured epithelial cells demonstrated vinculin in areas that appear to be associated with filamentous actin. Vinculin was associated with cell membranes in human cornea. The expression of alpha 2 integrin observed in chondrocytes fixed with methanol, paraformaldehyde, or formaldehyde is consistent with its role in cell-substrate interaction, but may also suggest a role in dividing and differentiating cells. The localization of alpha 2 integrin in human corneal epithelia supports its role as a cell-cell adhesion molecule. The cytoplasmic distribution of vinculin and alpha 2 integrin in tissues fixed without detergent extraction suggests that the fixation step may be sufficient for antibody penetration and antigen extraction. These studies are the first report of vinculin and alpha 2 integrin in embryonic chondrocytes. In addition we have shown that confocal laser scanning microscopy combined with proper fixation and extraction protocols may optimize the localization of antigens in cultured and whole mount cells.

Animals↗
PubMed1994

High level expression in Escherichia coli and characterization of the EF-hand calcium-binding protein caltractin.

Caltractin is a member of the calmodulin superfamily of Ca(2+)-binding proteins that was originally cloned at the DNA level from the unicellular green alga Chlamydomonas reinhardtii. Human and mouse homologs to algal caltractin have been recently characterized. In the studies reported here, recombinant Chlamydomonas caltractin was expressed at high levels in Escherichia coli and purified to homogeneity. The use of the ompT-host BL21 proved critical for obtaining high yields of homogeneous full-length protein. Growth and purification protocols were optimized to allow reproducible and efficient production of tens of milligrams of pure protein from 1-liter cultures. Caltractin has a distinct UV spectrum which is largely dominated by the fine structure due to the 9 Phe residues. Unlike other members of the same protein family, the UV and the CD spectra do not change upon addition of Ca2+ to the apoprotein. However, the 1H NMR spectrum shows distinct changes upon Ca2+ binding, which are indicative of structural and/or dynamic changes largely reminiscent of other members of the calmodulin superfamily. Ca2+ binding measurements demonstrated the binding of four Ca2+ ions to caltractin with two higher affinity (Kd = 1.2 x 10(-6) M) and two lower affinity (Kd = 1.6 x 10(-4) M) sites. Caltractin is highly stable in both the apo- and the Ca(2+)-loaded states. The unusual stability of apocaltractin makes this protein highly suited for structural studies by multidimensional NMR aimed at understanding the structural and dynamic consequences of Ca2+ binding, and the molecular basis of Ca2+ signal transduction.

Amino Acid Sequence↗
PubMedDate not supplied

[Magnetic resonance in the diagnosis of pathologic changes in the infundibulum of the hypophyseal gland].

Magnetic resonance imaging (MRI) is a new, non-invasive neuroradiological diagnostic procedure for direct multiplanar visualization of the anatomic structures of pituitary gland infundibulum. MRI is extremely sensitive in demonstrating pathological changes of infundibulum, and is a method of choice for diagnosis of its breakage. Forty-eight patients with pituitary hypofunction have been examined on MRI to demonstrate empty sellae and/or breakage of infundibulum. Pathological changes of infundibulum were found in 11 patients, five of which had breakage (congenital or traumatic). Optimal MRI protocol, with application of paramagnetic contrast agent, for examination of pituitary gland has been established.

Humans↗
PubMed1993

Pros and cons of transgenic mouse mutagenesis test systems.

Over the last two years, first results of transgenic mouse mutagenicity assays have appeared in the literature. If sufficiently sensitive, this new in vivo transgenic mouse assay may be the first approach that allows us to measure frequencies of induced point mutations for any suspected target organ in mice. It may also be useful as a routine assay and could complement or replace the mouse spot test or the specific locus test. Different transgenic mouse strains exist that can be employed for this assay. This review summarizes some of the data that were generated with this promising novel in vivo test system. Remaining problems with its sensitivity and the question of the optimal test protocol are discussed.

Animals↗
PubMed1993

Analysis of volumetric changes in rat pancreatic islets under osmotic stress using laser scanning confocal microscopy.

Analysis of the volumetric changes in rat pancreatic islets undergoing shrinkage and/or swelling due to osmotic stress is essential for understanding the mechanism of mass transport between cells and their environment and for optimizing cryopreservation protocols. Addition and removal of cryoprotective additives is an integral component of all cryopreservation processes. We have used laser scanning confocal microscopy (LSCM) of acridine orange/propidium iodide (AO/PI) stained Islets of Langerhans to analyze the effects of osmotic stress induced by exposure to varying concentrations of the cryoprotectant dimethyl sulfoxide (DMSO), on the islet volume at two temperatures 23 degrees C and 15 degrees C. Experiments were conducted by mounting a single islet onto a unique freeze-thaw-perfusion stage on which the system temperature and the chemical composition of the solutions can be precisely controlled. The bathing medium of the islet was rapidly changed from isotonic saline to the desired DMSO osmolality to produce a defined osmotic stress, and the islet was imaged simultaneously using 488 nm argon laser. Three to seven serial sections were obtained through each islet at increments varying between 15 microns and 20 microns. The three-dimensional (3-D) image was segmented into islet and non-islet regions using a combination of median filtering, gray level thresholding and region labeling, and the islet volume was computed by counting voxels. Further, a special analysis algorithm was applied to identify shape changes both locally and globally throughout the islet volume.

Algorithms↗
PubMed1993

[Different evaluations of the staging of Hodgkin's and non-Hodgkin's lymphomas (NHL) with computer tomography and lymphography by different observers].

In this report, the differences in the evaluation of CT and lymphography findings by different observers is discussed. The study included 132 men and 79 women (146 NHL and 65 Hodgkin lymphomas). A total of 185 CT examinations and 78 lymphographies were available for reevaluation. In the lymphographies, discongruent findings were reported twice as frequently as in the CT scans (15% and 9%). An optimized examination protocol for CT and consistent criteria for the interpretation of lymphographic findings could possible lead to a better diagnostic evaluation.

Adolescent↗
PubMed1993

Treatment of adult chronic autoimmune thrombocytopenic purpura with repeated high-dose intravenous immunoglobulin.

Intravenous (i.v.) infusions of Ig concentrates are an effective but expensive treatment for patients with autoimmune thrombocytopenic purpura (AITP). The optimal treatment protocol and the long-term results are uncertain, and the precise mechanism by which the platelet count increases is poorly understood. Twenty adult patients with chronic AITP were enrolled in a prospective study to compare the respective efficacy of two high-dose IVIgG induction regimens (1 g v 2 g/kg body weight) and the long-term effect of six 1 g/kg body weight i.v. IgG reinfusions. An initial response was observed in all 18 evaluable patients: the platelet count increased to a mean value of 251 x 10(9)/L (range 72 to 836 x 10(9)/L) and the mean pretreatment platelet count was multiplied by 14.6. No difference in efficiency was observed between the two i.v. IgG dosages. The degree of the platelet count increment correlated in both groups with the increase in the clearance of antibody-coated red blood cells, measured by an isotopic method, but not with the serum IgG elevation. Treatment was considered to have failed in 11 patients, 90 days after the last i.v. IgG reinfusion (D90), because the platelet counts were comparable with pretreatment values. In contrast, a complete response was observed at D90 in five patients (mean platelet count: 184 x 10(9)/L; range: 150 to 250 x 10(9)/L) and a partial response at D90 was obtained in the remaining two patients (platelet counts: 70 and 104 x 10(9)/L). Five of the 7 responders at D90 kept a platelet count above 50 x 10(9)/L during the entire follow-up period (mean 33 months; range: 5 to 66) with no further treatment; unfortunately, no clinical or biologic criteria were found to be predictive of the long-term response. This study shows that an i.v. IgG infusion regimen of 1 g/kg body weight could safely replace the classical 2 g/kg body weight dosage, at least in patients who do not have life-threatening thrombocytopenia. Moreover, repeated i.v. IgG reinfusion could be an alternative for AITP patients in whom splenectomy is contraindicated.

Adult↗
PubMed1993

Gait analysis. An essential tool in the treatment of cerebral palsy.

Gait analysis has radically changed the treatment of cerebral palsy. Preoperatively, it allows critical assessment of the specific pathologies of the patient. Postoperatively, it provides an accurate assessment of outcome. This assessment of outcome has in turn allowed the accurate critique of surgeries and has made it possible to discard treatments that are not useful or are perhaps even injurious. As a result of this continual reassessment of surgical techniques, several principles and insights regarding the treatment of cerebral palsy have been learned. These include (1) the importance of reestablishing normal gait prerequisites, (2) the methods of reducing the energy expenditure of the pathologic gait, (3) the importance of skeletal structures in providing the lever arm by which muscles produce moments around joints, (4) the role and importance of two joint muscles, and (5) the importance of separating abnormalities, which are emanating from the neurologic lesion, from secondary ("coping") responses. Through gait analysis, it has become apparent that diplegia and hemiplegia are noninclusive terms, each of which contain a variety of homogeneous patterns of gait. Eventually these patterns may be separated and identified and optimal treatment protocols for each pattern type developed.

Biomechanical Phenomena↗
PubMed1993

Mechanisms of adoptive immunotherapy: improved methods for in vivo tracking of tumor-infiltrating lymphocytes and lymphokine-activated killer cells.

Adoptive immunotherapy with tumor-infiltrating lymphocytes (TIL) and lymphokine-activated killer cells has been demonstrated to mediate regression of tumors in murine models and in selected patients with advanced cancer. Improved methods for monitoring immune cell traffic, particularly to sites of tumor, are needed to elucidate mechanisms of antitumor activity and optimize treatment protocols. Traditional cell tracking methods such as fluorescent protein labeling and radiolabeling using 111In, 125I, or 51Cr are limited by isotope half-life, leakage or transfer of label from immune cells, and toxicity or altered cell function caused by the labeling process. Labeling with genetic markers allows long-term cell tracking but is laborious to perform and difficult to quantitate. We have used two recently described lipophilic cell tracking compounds (PKH26 and 125I-PKH95) which stably partition into lipid regions of the cell membrane to track immune cells in vivo. Concentrations of each tracking compound which had no adverse effects were determined for a variety of murine TIL and lymphokine-activated killer cell functions. Viability was unimpaired at labeling concentrations of up to 5 microM for PKH95 and 20 microM for PKH26. TIL proliferation was unaltered by labeling with up to 5 microM PKH95, 20 microM PKH26, or a combination of 15 microM PKH26 and 5 microM PKH95. In vivo cytotoxic effector function and in vivo therapeutic efficacy of lymphokine-activated killer cells and TIL were also unimpaired by labeling with 20 microM PKH26 or 1 microM 125I-PKH95. Subsequent studies in an adoptive transfer immunotherapy model used 125I-PKH95 to track the biodistribution of TIL in tumor and in non-tumor-bearing animals and PKH26 fluorescence to monitor microdistribution within tissues and distinguish TIL from host T-cells. The results suggest that differential accumulation, selective retention, or proliferation at the tumor site cannot account for the observed pattern of therapeutic efficacy. We hypothesize that a minimum number of TIL must reach the tumor site in order to achieve a demonstrable therapeutic effect.

Animals↗
PubMed1995

[Preparation and separation of milligram amounts of canine fibrin(ogen) degradation products (fdp) X, Y, D and E].

In the present investigation we first produced canine fibrinogen degradation products (FDP) following two optimized degradation protocols. These FDP-mixtures, which were alternatively enriched with X and Y fragments or D and E fragments, were purified further to individual FDP X, -Y, -D, and -E with > 95% purity by the means of two low pressure column chromatographic techniques (size exclusion chromatography and anionexchanger chromatography). With this techniques the FDP D could be separated into four different D subfractions. No satisfactory results were yielded by hydrophobic interaction chromatography (HIC) with C5-Alkylsuperose, chromato-focusing and separations with hydroxyapatit. The observed strong binding of fragment E on hydroxyapatit probably points to the maintenance of the calcium binding site on the prepared canine E-fragment.

Animals↗
PubMedDate not supplied

Circulating progenitor cell collection: experience from 275 leukaphereses in various malignancies and in healthy donors.

BACKGROUND: Blood cell transplantation has become a new type of support in high-dose chemotherapy (HDC) for several oncologic and hematologic diseases. Over the last few years the demand for circulating progenitor cell (CPC) collection by blood cell separators has grown dramatically, and transfusion services must manage new CPC programs. MATERIALS AND METHODS: A protocol for optimizing the collection and clinical use of CPC is described. The results of 275 harvestings were studied: 128 patients were divided into 5 groups according to tumor type (A: breast cancer; B: Hodgkin's disease; C: non-Hodgkin lymphoma; D: multiple myeloma; E: various solid tumors). An additional group (F) consisted of 11 healthy donors. Factors affecting collection (mobilizing regimen or previous radiation therapy) and side effects were investigated. RESULTS: The mean values of mononuclear cells (MNC x 10(7)/kg) and CD34+ cells (x 10(6)/kg) collected per leukapheresis in the 6 respective groups were: 31.4 and 4.6 in group A; 26.4 and 3.4 in group B; 21.8 and 5.8 in group C; 24.6 and 2.4 in group D; 26.8 and 2.9 in group E; 60 and 6 in group F. Previous chemotherapy and/or radiation therapy were the main factors influencing CPC harvesting. The different chemotherapy regimens employed demonstrated no significant differences in their mobilizing efficacy. Side effects related to leukapheresis were few (2.3% of the procedures) and manageable. CONCLUSIONS: CPC collection is feasible in a wide range of clinical situations. Careful clinical evaluation of patients, accurate monitoring of progenitor cell release and collection timing are important for obtaining a sufficient number of CPC for hemopoietic recovery. Previous chemotherapy and radiotherapy are the main factors influencing CPC harvests. The mobilizing regimens employed showed no substantial differences in their efficacy.

Adult↗