Intercalation Pseudocapacitance of Cation-Exchanged Molybdenum-Based Polyoxometalate for the Fast and Stable Zinc-Ion Storage

Recently, intercalation pseudocapacitance has received significant interest as an abnormal charge storage mechanism owing to the battery-like intercalation energy storage into the bulk electrodes and the fast charge storage kinetics of electrochemical capacitors. However, intercalation pseudocapacitance of molybdenum-based polyoxometalates (POMs) for high-performance Zn ion battery (ZIB) cathodes is yet to be exploited. Herein, we demonstrate the fast and reversible intercalation pseudocapacitance of vanadium-substituted Keggin-type molybdenum-based POMs (XPMoV), where H of HPMoV is replaced by X cations (X = Li, Na, K, or Rb). This cation exchange allows cation-exchanged XPMoV to exhibit the morphological evolution into an anisotropic rodlike structure and to achieve a pillar effect on the improved chemical and structural integrity. Despite the micron-size rod morphology and the contracted lattice of (100) plane, the intercalation pseudocapacitance kinetics of XPMoV was dominated by the fast surface-confined electrochemistry and became highly reversible after the 1st cycle activation process by co-intercalation of Li+ and Zn2+ ions. Therefore, the ZIB with the KPMoV cathode delivered a high rate capability of 74.0 mAh g-1 at 20,000 mA g-1 and 87% capacity retention over 2000 cycles at 1000 mA g-1, far exceeding HPMoV and other Mo-based cathodes. This study paves the way to design the fast and reversible intercalation pseudocapacitance of POMs and the cation exchange chemistry into the improved (electro)chemical and structural integrity.

Iron Gall Ink Revisited: In Situ Oxidation of Fe(II)-Tannin Complex for Fluidic-Interface Engineering

The ancient wisdom found in iron gall ink guides this work to a simple but advanced solution to the molecular engineering of fluidic interfaces. The Fe(II)-tannin coordination complex, a precursor of the iron gall ink, transforms into interface-active Fe(III)-tannin species, by oxygen molecules, which form a self-assembled layer at the fluidic interface spontaneously but still controllably. Kinetic studies show that the oxidation rate is directed by the counteranion of Fe(II) precursor salts, and FeCl₂ is found to be more effective than FeSO₄ -an ingredient of iron gall ink-in the interfacial-film fabrication. The optimized protocol leads to the formation of micrometer-thick, free-standing films at the air-water interface by continuously generating Fe(III)-tannic acid complexes in situ. The durable films formed are transferable, self-healable, pliable, and postfunctionalizable, and are hardened further by transfer to the basic buffer. This O₂ -instructed film formation can be applied to other fluidic interfaces that have high O₂ level, demonstrated by emulsion stabilization and concurrent capsule formation at the oil-water interface with no aid of surfactants. The system, inspired by the iron gall ink, provides new vistas on interface engineering and related materials science.

Salt-Induced, Continuous Deposition of Supramolecular Iron(III)-Tannic Acid Complex

One-step assembly of iron(III)-tannic acid (Fe³⁺-TA) complex forms nanothin (∼10 nm) films on various substrates within minutes. In this deposition scheme, however, the film does not grow continuously over time even though Fe³⁺-TA complex is still abundant in the coating solution. In this paper, we report that the salt addition dramatically changes the one-off coating characteristic to continuous one, and each salt has its optimum concentration ( C_MFT) that produces maximum film thickness. For detailed investigation of the salt effects, we employed various salts, including LiCl, NaCl, KCl, CaCl₂, SrCl₂, BaCl₂, NaBr, and NaNO₃, and found that only cations played an important role in the continuous deposition of the Fe³⁺-TA complex, with smaller C_MFT values for the cations of higher valency and larger size. On the basis of the results, we suggested that the positively charged cations screened the negative surface charges of Fe³⁺-TA complex particles, leading to coagulation and continuous deposition, further supported by the ζ-potential measurement and time-resolved dynamic light-scattering analysis.

Enzymatic film formation of nature-derived phenolic amines

An enzyme-instructed method is developed for material-independent, cytocompatible coating of phenolic amines, inspired by melanogenesis found in nature. Tyrosinase-based film formation proceeds smoothly in an aqueous solution at neutral pH, and can use various phenolic amines including catecholamines, such as tyrosine, tyramine, dopamine, norepinephrine, and DOPA, as a coating precursor. Compared with polydopamine coating, the method is fast and efficient, and forms uniform films. Its high cytocompatibility is advantageously applied to cell-surface engineering, where chemically labile Jurkat cells are coated individually without any noticeable decrease in viability. Considering the huge potential of polyphenolic-based coatings, the strategy developed herein will provide an advanced tool for manipulating biological entities, including living cells, in biomedical and medicinal applications.

Nanofiber mats composed of a chitosan-poly(d,l-lactic-co-glycolic acid)-poly(ethylene oxide) blend as a postoperative anti-adhesion agent

Postoperative tissue adhesion causes serious complications and suffering in 90% of patients after peritoneum surgery, while commercial anti-adhesion agents cannot completely prevent postoperative peritoneal adhesions. This study demonstrates electrospining of a blended solution of chitosan, poly(d,l-lactic-co-glycolic acid) (PLGA), and poly(ethylene oxide) (PEO) to fabricate a chitosan-based nanofibrous mat as a postoperative anti-adhesion agent. Rheological studies combined with scanning electron microscopy reveal that the spinnability of the chitosan-PLGA solution could be controlled by adjusting the blend ratio and concentration with average fiber diameter from 634 to 913 nm. Biodegradation of the nanofiber specimens showed accelerated hydrolysis by chitosan. Proliferation of fibroblasts and antimicrobial activity of nanofibers containing chitosan was analyzed. Abdominal defects with cecum adhesion in rats demonstrated that the blend nanofiber mats were effective in preventing tissue adhesion as a barrier (4 weeks after abdominal surgery) by coverage of exfoliated peritoneum and insufficient wound sites at the beginning of the wound healing process. Chitosan-PLGA-PEO blend nanofiber mats will provide a promising key as a postoperative anti-adhesion agent. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1906-1915, 2017.

Peroneal nerve palsy after compression stockings application

Peroneal nerve palsy can be caused by various etiology. We report unilateral peroneal nerve palsy after compression stockings application. A 64-year-old man underwent off-pump coronary bypass graft. Surgeon did not use saphenous vein for the bypass graft. Sedation was stopped after 3 h postoperative. After 16 h, for prophylaxis of deep vein thrombosis, knee-high elastic stocking was applied. After 1 h, he took off right stocking because of numbness but left stocking was kept. After 24 h postoperative, (8 h after stocking application) patient complained suddenly left foot drop. Manual muscle test revealed 0/5 of ankle dorsiflexion, ankle eversion, and toe extension. Sensory was decreased to 70% in lower half of anterolateral aspect of tibia, foot dorsum, and toes. Foot drop and sensory abnormality decreased in 3 weeks. Cardiac surgery patients already have many risk factors for peripheral neuropathy. Clinicians should be careful when applying stockings on those patients.

Quality evaluation and pattern recognition analyses of bioactive marker compounds from Farfarae Flos using HPLC/PDA

The flower bud of Tussilago farfara L., called Farfarae Flos, has traditionally been used in Oriental medicine for the treatment of bronchitis and asthma. To establish a standard for quality control as well as the reliable identification of Farfarae Flos, the contents of five standards, rutin (1), isoquercetin (2), 3,5-dicaffeoylquinic acid (3), tussilagone (4), and tussilagonone (5), were determined by quantitative high-performance liquid chromatography (HPLC)/photodiode array (PDA) analysis. The five standards were separated on a YoungJinBioChrom Aegispak C18-L (250-mm×4.6-mm, 5-µm) column by gradient elution using 0.03% trifluoroacetic acid in water (A), with acetonitrile (B) as the mobile phase. The flow rate was 1.0 mL/min, and the UV detector wavelength was set at 220 nm. The method was successfully used in the analysis of Farfarae Flos from different geographic origins with relatively simple conditions and procedures, and the results demonstrated satisfactory linearity, recovery, precision, accuracy, stability, and robustness. The HPLC analytical method for pattern recognition analysis was validated by repeated analysis of 62 Farfarae Flos samples. This result indicated that the established HPLC/PDA method is suitable for quantitation and pattern recognition analyses for the quality evaluation of Farfarae Flos.

Quantitative and pattern recognition analyses of magnoflorine, spinosin, 6'''-feruloyl spinosin and jujuboside A by HPLC in Zizyphi Semen

Two rapid and simple HPLC methods with UV detector to determine three main compounds (magnoflorine, spinosin and 6′′′-feruloyl spinosin) and evaporative light scattering detector (ELSD) to determine jujuboside A were developed for the chemical analyses of Zizyphi Semen. Magnoflorine, spinosin, and 6′′′-feruloyl spinosin were separated with an YMC J’sphere ODS-H80 column (250 mm × 4.6 mm, 4 μm) by the gradient elution followed by the isocratic elution using methanol with 0.1 % formic acid and water with 0.1 % formic acid as the mobile phase. The flow rate was 1.0 mL/min. Jujuboside A was separated by HPLC–ELSD with YoungJinBioChrom Aegispak C18-L column (250 mm × 4.6 mm, 5 μm) column in a gradient elution using methanol with 0.1 % formic acid (A) and water with 0.1 % formic acid as the mobile phase. These two methods were fully validated with respect to linearity, precision, accuracy, stability, and robustness. These HPLC methods were applied successfully to quantify four compounds in a Zizyphi Semen extract. The HPLC analytical methods were validated for pattern recognition analysis by repeated analysis of 91 seed samples corresponding to 48 Zizyphus jujuba var. spinosa (J01–J48) and 43 Zizyphus mauritiana (M01–M43). The results indicate that these methods are suitable for a quality evaluation of Zizyphi Semen.

The effect of P2X7 receptor activation on nuclear factor-κB phosphorylation induced by status epilepticus in the rat hippocampus

Nuclear factor-kappa B (NFκB) signal is essential for neuronal survival and its activation may protect neuron against various stimuli. Since purinergic signals activate NFκB through the P2X7 receptor, we investigated the distinct pattern of NF-κB phosphorylation in neurons by P2X7 receptor activation following status epilepticus (SE) in an effort to understand the role of P2X7 receptor in epileptogenic insult. In non-SE animals, 2'(3')-O-(4-benzoyl)benzoyl adenosine 5'-triphosphate (BzATP, a P2X7R agonist) treatment increased only p52-Ser869 NF-κB phosphorylation in neuron. Following SE, p52-Ser865, p52-Ser869, p65-Ser276, p65-Ser311, p65-Ser468, and p65-Ser529 NF-κB phosphorylation was significantly decreased in CA1 and CA3 neurons. However, BzATP treatment prevented reductions in p65-Ser276, p65-Ser311, p65-Ser529, and p52-Ser869 NF-κB phosphorylations in CA1 and/or CA3 neurons induced by SE. Furthermore, BzATP treatment reduced SE-induced p65-Ser311, p65-Ser468, p65-Ser536, and p52-Ser869 NF-κB phosphorylations in astrocytes. These findings indicate that P2X7 functions may be involved in the regulation of SE-induced reactive astrocytes and neuronal degeneration via NF-κB phosphorylations in response to pilocarpine-induced SE in the rat hippocampus.

Consensus of Mobile Robots under Markovian Communication

For mobile robots moving in a plane, the mean square consensus problem is investigated under Markovian communication of partly known transition probabilities. Based on linear matrix inequalities, bisection search and numerical optimization, a design method is presented of feedback gains guaranteeing mean square consensus.

Interleukin-18 attenuates disruption of brain-blood barrier induced by status epilepticus within the rat piriform cortex in interferon-γ independent pathway

Status epilepticus increases brain-blood barrier (BBB) permeability leading to vasogenic edema. This BBB disruption is usually confined within relatively limited cerebral regions including the piriform cortex (PC), and leads to epileptogenesis and contributes to progression of epilepsy. Although cytokines are at least partly responsible for changes in BBB permeability, the role of interleukin-18 (IL-18) in vasogenic edema is not yet explored in detail. In the present study, we investigated the role of IL-18 in SE-induced vasogenic edema formation. Following SE, IL-18/interferon-γ (IFN-γ) system was up-regulated in astrocytes and microglia/macrophages. Recombinant rat (rr) IL-18 infusion decreased vasogenic edema formation, while anti-rat IL-18 infusion increased it. In contrast, rrIFN-γ, and anti-rat IFN-γ infusion showed reverse effects on vasogenic edema formation. rrIL-18 or anti-rat IFN-γ IgG infusion elevated dystrophin expression accompanied by the reduction in vasogenic edema. However, rr-IFN-γ or anti-rat IL-18 IgG infusion significantly decreased dystrophin immunoreactivity within the PC following SE. These findings indicate that IL-18-mediated up-regulation of dystrophin expression may play either a direct or indirect role in maintenance of BBB function following SE. Therefore, our findings suggest that IL-18 may have protective effect on SE-induced BBB disruption in IFN-γ independent mechanism.

Comparison of a supraclavicular block showing upper arm twitching response with a supraclavicular block showing wrist or finger twitching response

Background

Although an ultrasound-guided brachial plexus block has become the standard, conventional brachial plexus blocks with a paresthesia or muscle twitch are still performed. However despite eliciting a paresthesia or muscle twitch, there are some cases in whom the brachial plexus block fails. This has been attributed to the difference between the proximal response (PR) and distal response (DR). Therefore, this study compared a supraclavicular block showing a PR with that showing a DR. In addition, clinical data such as success rate, onset time, and complications were examined.

Methods

Eighty three patients received a supraclavicular block with a nerve stimulator. All blocks were performed with 1% mepivacaine 40 ml. The subjects were divided into two groups-Group PR (n = 20, contraction of triceps or biceps) and Group DR (n = 63, flexion or extension of wrist or fingers) according to the types of muscle twitch. The success rate, onset time, and complications were measured and evaluated.

Results

The success rate of Group DR (93.7%) was higher than that of Group PR (75.0%) (P < 0.05). The onset times of Group PR and DR were 15.3 ± 6.7 min and 14.4 ± 6.0 min, respectively.

Conclusions

The elicitation of a DR was more effective in increasing the success rate and reducing the onset time than the elicitation of a PR in a single-injection supraclavicular block.

Cases series: ultrasound-guided supraclavicular block in 105 patients

Background

Multiple needle attempts to gain a muscle twitch or a paresthesia for a classical supraclavicular brachial plexus block can increase the risks of nerve damage or pain. The aims of this study were to obtain reliable clinical data on ultrasound-guided supraclavicular blocks, demonstrate the higher success rate and fewer complications, and design an injection method for patients whose brachial plexus can not be located.

Methods

105 patients received an ultrasound-guided supraclavicular block. 40 ml of 1% mepivacaine was injected without a muscle twitch or paresthesia. The groups were divided into two groups - Group A (n = 92, patients who had visible brachial plexus) and Group B (n = 13, patients whose brachial plexus can't be located). After the blocks, the clinical characteristics such as the success rate, the time to onset, the extent of the sensory block, and occurrence of complications were evaluated.

Results

The Success rate of Group A (98.9%) was higher than that of Group B (84.6%) (P < 0.05). The overall success rate was 97.1%. All patients could be operated on under sedation. The time to onset of Group A (12.6 ± 4.4 min) was shorter than that in Group B (23.1 ± 5.1 min) (P < 0.05). The overall time to onset was 13.8 ± 5.5 min. There were no serious complications such as pneumothorax.

Conclusions

An ultrasound-guided supraclavicular block is very effective in even patients whose brachial plexus can not be located.

Induction of Apoptosis by (Z)-Stellettic Acid C, an Acetylenic Acid from the Sponge Stelletta sp., Is Associated with Inhibition of Telomerase Activity in Human Leukemic U937 Cells

BACKGROUND

(Z)-stellettic acid C, an acetylenic acid from the marine sponge Stelletta sp., has been shown to have cytotoxic activity in some cancer cells; however, its mechanisms on malignant cell growth are not known. In this study, the potential of (Z)-stellettic acid C to induce apoptosis in human leukemic U937 cells and its effects on telomerase activity were investigated.

METHODS

Cytotoxicity was evaluated by MTT assays. Apoptosis was detected using DAPI staining and annexin V fluorescein. The mRNAs of Bcl-2, inhibitor of apoptosis proteins (IAPs) family and Fas/FasL system were determined by RT-PCR. Caspases and telomerase activities were measured using colorimetric assay and telomeric repeat amplification protocol enzyme-linked immunosorbent assay (TRAP-ELISA), respectively.

RESULTS

Exposure of U937 cells to (Z)-stellettic acid C resulted in growth inhibition and induction of apoptosis in a dose-dependent manner, which was associated with the modulation of Bcl-2 family expression, activation of caspases and downregulation of IAPs family members. (Z)-Stellettic acid C treatment markedly inhibited the activity of telomerase in a dose-dependent fashion. Additionally, the expression of human telomerase reverse transcriptase, a main determinant of the telomerase enzymatic activity, was progressively downregulated by (Z)-stellettic acid C treatment.

CONCLUSIONS

These results suggest that (Z)-stellettic acid C could have a possible cancer therapeutic potential.

Anti-inflammatory effect of jeongshintang through suppression of p38 activation in human astrocytoma, U373MG cells

Jeongshintang (JST) is a Korean herbal prescription, which has been successfully used for cerebral diseases. However, the anti-inflammatory effect of JST on Alzheimer's disease (AD) is still not fully understood. In this study, we investigated the effects of JST in attenuating the inflammatory response induced by interleukin (IL)-1beta plus beta-amyloid [1-42] fragment (A beta) in the human astrocyte cell line, U373MG. The production of IL-6, IL-8, and prostaglandin (PG)E2 was significantly increased by IL-1beta plus A beta (1-42) in a time-dependent manner (P < 0.05). JST significantly inhibited the IL-1beta plus A beta (1-42)-induced IL-6, IL-8, and PGE2 production at 24 h (P < 0.05). Maximal inhibition rate of IL-6, IL-8, and PGE2 production by JST was about 54.40%, 56.01%, and 44.06% respectively. JST (0.01-1 mg/ml) also attenuated the expression of cyclooxygenase (COX)-2 and activation of p38 MAPK induced by IL-1beta and A beta (1-42). These results demonstrated that JST has an anti-inflammatory effect, which might explain its beneficial effect in the treatment of various neurodegenerative diseases such as AD.

Methylation of p16(INK4A) and p57(KIP2) are involved in the development and progression of gastric MALT lymphomas

p16(INK4A) and p57(KIP2) are inhibitors of cyclin-dependent kinases and their inactivation by methylation has been reported as a major tumorigenic mechanism in tumors. To examine whether methylation of p16(INK4A) and p57(KIP2) is involved in the development and progression of gastric MALT lymphomas, 24 gastric low-grade lymphomas of MALT, 11 diffuse large B-cell lymphomas, and 10 each case of gastric lymphoid follicles with and without Helicobacter pylori infection were studied. H. pylori infection was positive in 85.7% of the gastric lymphomas. In the gastric lymphoid follicles positive for H. pylori, methylation of p16(INK4A) was detected in 10% of cases, while methylation of p57(KIP2) was not detected. In low-grade MALT lymphomas, p16(INK4A) and p57(KIP2) were methylated in 41.7 and 29.2% of the cases, respectively. In diffuse large B-cell lymphomas, methylation of p16(INK4A) and p57(KIP2) was found in 72.7 and 36.4% of the cases, respectively. All but one case with p16(INK4A) and p57(KIP2) methylation was H. pylori positive and most of them were stage I. Our results indicate that methylation of p16(INK4A) followed by p57(KIP2) methylation involves during the tumorigenesis of gastric MALT lymphomas associated with H. pylori infection. As methylation of these two genes was more frequent in the higher grade (P<0.05), it may contribute to the malignant progression of gastric MALT lymphomas.

Intracellular IL-4, IL-10, and IFN-gamma levels of leukemic cells and bone marrow T cells in acute leukemia

The quantitative levels of intracellular cytokines IL-4, IL-10, and IFN-gamma (ie, the number of bound PE-conjugated antibody molecules/cell) of leukemic cells and bone marrow T cells (bmT cells) of acute leukemia patients were analyzed by flow cytometry. One hundred, thirty-one (95 AML, 25 ALL, 11 ABL) patients were studied. The leukemic cell IL-4 level was highest in the monocytic AML group (1735 +/- 1056) and lowest in the dysplastic AML group (960 +/- 545). The IFN-gamma level was highest in the acute promyelocytic leukemia (APL) group (495 +/- 159), and lowest in the ALL group (252 +/- 119). The IL-10 level was not significantly different among the diagnosis groups. In bmT cells, the IL-10 level was highest in the dysplastic AML group (972 +/- 1049) and lowest in the APL group (397 +/- 352). The leukemic cell cytokine levels were lowest and bmT cell cytokine levels were highest in the dysplastic AML group. There were no significant correlations of these cytokine levels with 2-yr survival rate, complete remission (CR) rate, or relapse rate. The cytokine levels of bmT cells at the time of CR became normal and were not different among the diagnosis groups. In summary, leukemic cell and bmT cell cytoplasmic expression profiles of IL-4, IL-10, and IFN-gamma are characteristic for each diagnostic group of acute leukemia patients and the profiles of bmT cells are normal at the time of CR.

Plasma soluble interleukin-2 receptor (sIL-2R) levels in patients with acute leukemia

The plasma soluble interleukin-2 receptor (sIL-2R) level was higher in 137 patients with acute leukemia (1,489 +/- 1,798 U/ml, including 98 cases of acute myeloid leukemia (AML), 1,063 +/- 1,414 U/ml, and 39 cases of acute lymphoblastic leukemia (ALL), 2,561 +/- 2,194 U/ml), compared to 49 normal control subjects, 421 +/- 151 U/ml). The ALL patients showed elevated plasma sIL-2R levels more frequently than the AML patients (92.3% vs 44.9%). No patient with either hypoplastic AML or AML with multilineage dysplasia and only 1 of 13 patients with acute promyelocytic leukemia (APL) had an elevated plasma sIL-2R level. All the My+ ALL patients (15 cases) showed elevated plasma sIL-2R levels. Plasma sIL-2R levels were significantly lower after chemotherapy in the ALL patients, but were not significantly lower in the AML patients. IL-2R was expressed on the leukemic cells in 36 (53.7%) of 67 AML and in 9 (21.4%) of 42 ALL cases. None of the AML M3, M4, M5, M6, or M7 subgroups showed IL-2R expression. The My+ ALL patients (42.9%, 6/14) showed IL-2R expression more frequently than the other ALL subgroups (10.7%, 3/28) (p = 0.025). The plasma sIL-2R level was correlated with the proportion of leukemic cells expressing IL-2R in acute leukemia. However, there were many cases, particularly ALL cases, who had elevated plasma sIL-2R levels without IL-2R expression on their leukemic cells. These results suggest that the plasma sIL-2R level is a valuable marker for monitoring ALL after chemotherapy, particularly in My+ ALL cases, and that the T cell immune reaction to leukemia appears to be much higher in ALL patients than in AML patients.

Expression of functional markers in acute lymphoblastic leukemia

We analyzed surface antigens, multidrug resistance (MDR) parameters (PGP, MRP, LRP), tissue infiltration parameters (CD18, CD44, VCAM, MMP2), receptors for colony stimulating factors (G-CSFr, GM-CSFr) and cell cycle parameters (Ki-67, topoisomerase IIalpha) in 86 patients with acute lymphoblastic leukemia (ALL). LRP, PGP and CD18 were associated with poor clinical outcome, and LRP expression was related with CD18, CD44 and G-CSFr. Of the cell cycle parameters, Ki-67 (+) fraction was increased in ALL with hepato-splenomegaly and extramedullary involvement. In conclusion, analysis of LRP, PGP, CD18 and Ki-67 could be helpful to predict the clinical behavior of ALL.

Molecular characterization of foot-and-mouth disease virus O/SKR/2000

Molecular cloning and sequencing of the genome of foot-and-mouth disease virus (FMDV) O/SKR/2000, one of PanAsia strain, were performed from FMDV infected cattle. From the poly (C) tract of the 5' nontranslated region (NTR) to the 3' NTR including 14 base pairs (bp) of poly (A) tail, 7813 bp sequences comprising approximately 95% of the whole genome were obtained by reverse transcription polymerase reaction (RT-PCR). The deduced amino acid sequences of the structural and nonstructural proteins (NSP) of the O/SKR/2000 virus were analyzed for the sequence similarity among type O strains. Comparison between FMDV O/SKR/2000 and other strains indicates that overall the number of amino acids appears to be conserved without any deletion in either NSP or capsid proteins, thus, suggesting that O/SKR/2000 evolved with minor difference from preexisting strains.

The association of HLA antigen and GVHD in allogeneic hemopoietic stem cell transplantation with histocompatible sibling donor: a single-center experience in Korea

We analyzed the association of HLA antigens with incidence of organ-specific graft-versus-host disease (GVHD) after allogeneic hemopoietic stem cell transplantation (allo-HSCT) from an HLA-matched sibling donor. We retrospectively reviewed the clinical records of allo-HSCT recipients and found 389 patients who had received matched-sibling HSCT. HLA types, GVHD grades, and the development of acute or chronic GVHD, factors that reflect a certain immunological impact associated with involved organs, were investigated. The overall incidence of acute and chronic GVHD was 24.8% (96 cases) and 21.2% (82 cases), respectively. The incidence of acute GVHD with grades II through IV was higher among patients who had HLA-B61 (P = .0153) and HLA-Cw3 (P = .0208). The donor sex (P = .0040) and the conditioning regimen (P = .0010) were also associated with severe acute GVHD. The extensive-type chronic GVHD incidence was higher in patients who had HLA-B54 (P = .0159). The donor sex (P = .0406) and the pretransplantation diagnosis (P = .0184) were other factors associated with the development of extensive-type chronic GVHD. Furthermore, HLA-B35 (P = .0226) and HLA-B54 (P = .0091) were associated with a higher incidence of severe acute skin GVHD and chronic skin and oral GVHD (in descending order of incidence rates). HLA-B7,27 was associated with chronic liver GVHD (P = .0476) in addition to other parameters including patient (P = .0246) and donor sex (P = .0019). This study shows that these remarkable HLA antigens may be potent transplantation immune regulators, but there is a need for further evaluation using larger study samples.

Role of p27(Kip1) in cAMP- and TGF-beta2-mediated antiproliferation in rabbit corneal endothelial cells

PURPOSE

To determine whether p27(Kip1) plays a role in antiproliferation mediated by antimitogens (cAMP and TGF-beta2) in rabbit corneal endothelial cells (CECs).

METHODS

Cell proliferation was assayed using a colorimetric method to determine the number of viable cells. Subcellular localization of cell cycle-regulatory proteins was determined by immunofluorescent staining, and expression of the proteins was analyzed by immunoblot analysis.

RESULTS

When cells were treated with cAMP or TGF-beta2, serum-mediated cell proliferation was inhibited in a dose-dependent manner. Simultaneous treatment of the two antimitogens did not show a synergistic effect on inhibition of cell growth. Expression of cell cycle-regulatory proteins, such as cyclin-D1, cyclin-E, cdk2, cdk4, p21(Cip1), and p27(Kip1) was determined using immunofluorescent staining. A strong nuclear staining was observed for p27(Kip1). The other proteins were not stained or were only very faintly stained. Treatment of cells with either cAMP or TGF-beta2 did not change the staining potential of any proteins other than p27(Kip1), but all cells were positive for nuclear p27(Kip1) when treated with either TGF-beta2 or cAMP. In contrast, mitogen (FGF-2)-containing medium decreased the number of p27(Kip1)-positive cells. When the expression level of p27(Kip1) was determined using immunoblot analysis in the cells treated either with FGF-2 alone or with a concomitant treatment with FGF-2 and cAMP for 24 hours, FGF-2 markedly decreased the p27(Kip1) level, and cAMP prevented the decrease in p27(Kip1) level induced by FGF-2. No such phenomenon occurred during a short-term exposure of cells to either FGF-2 or cAMP or to a combination of the two. When cells were stained for phosphorylated p27(Kip1), FGF-2 markedly enhanced the staining of phosphorylated p27(Kip1) in nuclei, whereas both cAMP and TGF-beta2 prevented the phosphorylation of p27(Kip1).

CONCLUSIONS

These findings suggest that both antimitogens upregulate the expression of p27(Kip1) as they prevent the decrease of the p27(Kip1) level mediated by mitogen. Furthermore, cAMP and TGF-beta2 may inhibit the G(1)-to-S transition by blocking phosphorylation of p27(Kip1), which is a prerequisite for nuclear export of the inhibitor molecule for degradation.

Differential activity of TGF-beta2 on the expression of p27Kip1 and Cdk4 in actively cycling and contact inhibited rabbit corneal endothelial cells

PURPOSE

To determine whether TGF-beta2 exerts inhibitory action in a density dependent manner in primary, first passage, and second passage corneal endothelial cells (CEC).

METHODS

Fifty percent confluent cultures were used for actively cycling cells and monolayers were used as contact inhibited cultures. Half of the experiments were performed in cells treated with TGF-beta2 at 10 ng/ml for 24 h. Subcellular localization of cyclin dependent kinase 4 (Cdk4), p27Kip1 (p27), and phosphorylated p27 (pp27) was determined by immunofluorescent staining followed by confocal laser microscopic analysis. Expression of proteins were analyzed by immunoblotting.

RESULTS

Before colocalization between Cdk4 and p27 was studied, the two proteins were respectively stained, either in growing cells for the presence of Cdk4 or in contact inhibited cultures for the presence of p27. Nuclear Cdk4 was observed in FGF-2 treated cells while nuclear staining of Cdk4 was lost in mitogen deprived or TGF-beta2 treated cells. On the other hand, a strong positive staining of nuclear p27 was observed in growth down regulated conditions, which was completely lost in growth up regulated conditions. When cells were double stained with Cdk4 and p27 antibodies, actively cycling cells contained nuclear Cdk4. Less than 10% of the primary cells were positive for Cdk4 staining, whereas all of the second passage CEC contained nuclear Cdk4. Conversely, p27 was not detected in actively cycling cells in either primary or passaged cells. Contact inhibited cells demonstrated nuclear p27 staining in all cells, but only a few cells were positive for nuclear Cdk4. Nuclear Cdk4 was absent when the actively cycling cells were treated with TGF-beta2, whereas TGF-beta2 did not induce the expression of nuclear p27 in the same cultures. In contact inhibited cells, TGF-beta2 did not affect the staining profiles of p27. In the first passage CEC, TGF-beta2 slightly increased the number of cells that were positive for nuclear Cdk4. When the effect of TGF-beta2 at the level of protein synthesis was determined, TGF-beta2 markedly downregulated Cdk4 synthesis and slightly upregulated p27 synthesis in actively cycling cells. On the other hand, TGF-beta2 did not exert the same effect on Cdk4 synthesis in contact inhibited cells as it did on actively cycling cells. Contact inhibited cells contained a high level of p27, and TGF-beta2 slightly upregulated p27 synthesis in these cells. When phosphorylated p27 was determined to be present, the nuclei of both actively cycling and contact inhibited cells contained phosphorylated p27 in the nuclei, regardless of the passage numbers. TGF-beta2 inhibited phosphorylation of p27 in actively cycling cells, but it had no effect on phosphorylation of p27 in contact inhibited cells.

CONCLUSIONS

These data suggest that Cdk4 and p27 expression is density dependent, and TGF-beta2 exerted its activity on actively cycling cells. In these cells, TGF-beta2 downregulated Cdk4 expression and prevented the phosphorylation of p27, which is a prerequisite for nuclear export of the inhibitor molecule for degradation. Thus, TGF-beta2 inhibits the G1/S transition while it maintains p27 in an active form in the nuclei during the exponential growth cell stage.

Identification of a putative DEAD-box RNA helicase and a zinc-finger protein in Candida albicans by functional complementation of the S. cerevisiae rok1 mutation

We identified two novel genes, CHR1 and CSR1, of the fungal pathogen Candida albicans, by functional complementation of the Saccharomyces cerevisiae rok1 mutation. The Rok1 protein is a member of the DEAD protein family of ATP-dependent RNA helicases. ROK1 is required for cell cycle progression and also for rRNA processing. The CHR1 gene product of 578 amino acids is highly homologous to the Rok1 protein (54% identity) and is considered to be a putative DEAD-box RNA helicase. We predict that the CSR1 gene encodes a 73 kDa protein of 612 amino acids with five zinc-finger motifs at the C-terminal region. CHR1 or CSR1 on a high-copy number plasmid showed a slow-growth phenotype in a condition where the ROK1 expression is turned on from the GAL1 promoter. This result is consistent with the lethality caused by the ROK1 overexpression. We conclude that CHR1 encodes a functional homologue of Rok1 protein and CSR1 is a heterologous suppressor of the rok1 mutation.

Ionizing radiation potentiates the induction of nitric oxide synthase by interferon-gamma (Ifn-gamma) or Ifn-gamma and lipopolysaccharide in bnl cl.2 murine embryonic liver cells: role of hydrogen peroxide

The effects of ionizing irradiation on the nitric oxide (NO) production in murine embryonic liver cell line, BNL CL.2 cells, were investigated. Various doses (5-40 Gy) of radiation made BNL CL.2 cells responsive to interferon-gamma alone for the production of NO in a dose-dependent manner. Small amounts of lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha) synergized with IFN-gamma in the production of NO from irradiated BNL CL.2 cells, even though LPS or TNF-alpha alone did not induce NO production from the same cells. Immunoblots showed parallel induction of inducible nitric oxide synthase (iNOS). NO production in irradiated BNL CL.2 cells by IFN-gamma or IFN-gamma plus LPS was decreased by the addition of catalase, suggesting that H(2)O(2) produced by ionizing irradiation primed the cells to trigger NO production in response to IFN-gamma or IFN-gamma plus LPS. Furthermore, the treatment of nongamma-irradiated BNL CL.2 cells with H(2)O(2) made the cells responsive to IFN-gamma or IFN-gamma plus LPS for the production of NO. This study shows that ionizing irradiation has the ability to induce iNOS gene expression in responsive to IFN-gamma via the formation of H(2)O(2) in BNL CL.2 murine embryonic liver cells.

Human basophils express CD22 without expression of CD19

BACKGROUND

Even modern automatic cell counters cannot count basophils precisely. Therefore, we need a rapid, accurate, precise, and easy method for counting basophils.

METHODS

Using flow cytometry, basophils (CD22+/CD19-) and B cells (CD22+/CD19+) were counted. Within a large lymphocyte light scatter gate, % basophils (G%baso) and % B cells (G%B) were determined from the total count. Another method of analysis was to make two regions (R1 for basophils and R2 for B cells) and to determine in those the % basophils (R1%baso) and % B cells (R2%B) without gating. The flow cytometric basophil counts of the blood of 21 normal controls and 43 chronic myelogenous leukemia (CML) patients were compared with manual basophil count (Ma%baso) and basophil count by Coulter electronic cell counter (Hialeah, FL) (Auto%baso). CD22+/CD19- cells were sorted by a FACSCalibur (Becton Dickinson, San Jose, CA).

RESULTS

The G%baso of all samples was 4.66 +/- 5.35%, and R1%baso was 4.23 +/- 4.88%, and they were well-correlated (r = 0.996, P < 0.001). The G%B of all samples was 1.55 +/- 1.68%, and R2%B was 1.59 +/- 1.67%, and they were also well-correlated (r = 0.993, P < 0.001). Their correlation was better in normal controls than in CML. G%baso was well-correlated to Ma%baso (r = 0.827) and Auto%baso (r = 0.806), and R1%baso was well-correlated to Ma%baso (r = 0.831) but showed poor correlation to Auto%baso (r = 0.734). Auto%baso revealed the poorest correlation to Ma%baso (r = 0.692). The sorted CD22+/CD19- cells were all basophils (99.48 +/- 0.30%), and they revealed CD13, CD33, and dim CD45 expression, whereas CD3, CD14, CD16, and HLA-DR were not detected on them.

CONCLUSIONS

We discovered a specific marker combination to identify basophils (CD22+/CD19-), and we suggest that flow cytometric analysis using these markers is an easy, reliable, and accurate method of basophil counting.

Effectiveness of rotor off fraction in allogeneic murine bone marrow transplantation with complete disparity of major histocompatibility

Counterflow centrifugal elutriation (CCE) has been a highly efficient physical method for separating T cells from bone marrow (BM) without impairing cell function and yield. To investigate the usefulness of CCE, the hematopoietic potential as well as the level of T cell contamination in rotor-off (R/O) fraction of BM was studied using a murine bone marrow transplantation (BMT) model [C3H/He (H-2k)-->BALB/C (H-2d)]. The total recovery of cells after CCE procedure was 71.4%. Morphologically, R/O fraction contained abundant mononuclear cells and a few lymphocytes. The numbers of colony forming unit for granulocyte/monocyte (CFU-GM), Sca-1+ cells, and T cells were compared among four fractions of CCE (fractions at flow rate of 17, 25, 28 mL/min, and R/O fraction). The number of CFU-GM per 10(5) nucleated cells in each fraction were significantly higher in R/O fraction (331.3 +/- 34.4) compared to unfractionated marrow (UM) (21.1 +/- 1.3) and fraction of 17 mL/min (FR 17) (23.7 +/- 2.2 ) (chi2 = 0.0044). Neither fraction of 25 mL/min (FR 25) nor fraction of 28 mL/min (FR 28) contained CFU-GM colonies. The concentration of Sca-1+ cells in R/O fraction was significantly higher (1.96-fold) than UM (p < 0.05), and 80.0 +/- 10.1% of Sca-1+ cells in UM were recovered in R/O fraction; 88.1% of Thy-1.2+ T cells were eliminated in R/O fraction (p < 0.05). Mice receiving UM after lethal irradiation (875cGy) suffered from severe graft-versus-host disease (GVHD) and all five died within 7 days after BMT procedure (Group A). Of interest, mice receiving mixture of R/O fraction with lymphocyte-rich fraction (FR 25 plus FR 28) to equalize T cell number as UM, developed severe GVHD and four out of five died (probability of survival; 20%) (Group B). Mice receiving R/O fraction had mild GVHD and four out of five survived for at least 90 days (probability of survival; 80%) (Group C). In group C, probability of survival (p = 0.0006) was higher, and severity of GVHD (p = 0.0043) and progression rate of GVHD (p = 0.02) was lower. In conclusion, the elutriated R/O fraction cells of BM have the advantages of stable engraftment and tolerable GVHD in murine allogeneic BMT with complete major histocompatibility disparity. This could be directly applicable to patients with high risk of GVHD and graft failure in upcoming clinical trials.

Acute lymphoblastic leukemia with maturation--a new entity with clinical significance

The diagnosis of 'ALL with maturation' (ALLm) is proposed. One hundred and one patients with untreated ALL were entered into this study. The diagnosis of ALLm was made when more than 20% of all nucleated elements in the bone marrow showed maturation beyond prolymphocytes by light microscopic examination. The mature-appearing leukemic cells showed the same immunophenotype to remaining lymphoblasts. The number of ALLm cases was 19 (18.8%). The mean age at presentation of ALLm was 29 +/- 18, older than that of 18 +/- 16 of the remaining typical ALL (ALLt) (P = 0.015). Remission was induced with daunorubicin, vincristine, prednisone and L-asparaginase. Only two of 19 ALLm patients achieved CR after 4 weeks induction chemotherapy. In contrast, 57 of 82 (69.5%) ALLt patients achieved CR after the same induction chemotherapy. There was no significant difference in immunophenotype of ALLm compared with ALLt. Labeling index of DNA topoisomerase IIalpha (TopoLI) was studied by immunohistochemistry. Initial TopoLI of ALLm (221 +/- 147) was much lower than that of ALLt (609 +/- 262, P = 0.005). Furthermore, the remaining leukemic cells after chemotherapy were not labeled with anti-DNA topoisomerase IIalpha. The P53 protein was expressed in nine of 18 ALLm cases (50.0%) and P-glycoprotein was not expressed in ALLm cases. Twelve of 19 ALLm cases were studied for carrying bcr/abl fusion by karyotyping and/or fluorescent in situ hybridization. Only two cases revealed bcr/abl fusion. In conclusion, ALLm is a separate entity of ALL which has a very poor clinical course and is independent of other prognostic factors. The morphologically mature leukemic cells are in resting GO phase.

Chromosomal numerical aberrations in gastric carcinoma: analysis of eighteen cases using in situ hybridization

Paraffin-embedded tumor cells of 18 cases of gastric carcinoma were hybridized with digoxigenin-labeled repetitive DNA probes specific for the centromeric regions of chromosomes X, Y, 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 15, 16, 17, 18, and 20. All cases demonstrated numerical chromosomal aberrations. The most exciting aberration, polysomy (five or more copies) of several chromosomes, was found in all cases except a case of mucinous adenocarcinoma, which showed trisomy 9 as the sole chromosomal numerical aberration. In nine cases of tubular adenocarcinoma, poorly-differentiated polysomies of several chromosomes were the consistent numerical aberration and monosomy 7, 18(2 cases each), 10, and 17(1 case each) were also found. In moderately-differentiated tubular adenocarcinoma all three cases also showed polysomies of several chromosomes. The total number of extra chromosomes (polysomy was counted as 5 copies) was higher in the intestinal type (mean 20.9) than in the diffuse type (mean 14.1). Regional lymph node metastasis, vein invasion, or perineural invasion was not related to any specific chromosomal numerical aberration in gastric cancer. Chromosomes X, 1, 2, 3, 4, 15, 17, and 20 had extra copies especially polysomy in most cases. However, chromosomes 7 and 18 revealed monosomy in many cases (31.3% and 33.3% respectively, and chromosome 9 and 11 revealed trisomy in 35.7% and 75% each. Numerically, the most conserved chromosome in gastric cancer was chromosome 12 (62.5%). By flow cytometry, two diploidy and 8 aneuploidy cases with the DNA indices from 1.30 to 1.85 were found.

The effect of HLA mismatching on graft survival in living-donor kidney transplants: Catholic Medical Center, 1984 to 1993

This study focuses on the beneficial effect of HLA matching on long-term graft survival rates in CsA-treated living primary kidney transplants at Catholic Medical Center, 1984 to 1993. 1. An impressive 26% difference in kidney graft survival was observed at 5 years between recipients who received 0 and 2 HLA-DR mismatches (79% vs 53%). 2. Five-year kidney graft survival rates in the 0, 1, 2, and 3-HLA-B+DR mismatches were 87%, 76%, 77%, and 74%, respectively, which was significantly different from 54% survival rates in the 4-HLA-B+DR mismatch group. 3. The 5-year kidney graft survivals in the 0, 1, 2, HLA-DR-mismatched living-nonrelated donor group were 84%, 76%, and 39%, respectively, which were significant differences. 4. The 5-year kidney graft survivals in the 0, 1, 2, HLA-DR-mismatched living-related donor group were 75%, 79%, and 72%, respectively, which were not significant. 5. The effect of HLA-A, B, A+B, A+DR, and A+B+DR mismatches showed little difference among the groups with different mismatch numbers. In conclusion, better matching for the HLA-DR, B+DR antigens significantly improved kidney graft survivals in our CsA-treated primary living-donor transplant recipients.

Allogeneic bone marrow transplantation for the patients with hemopoietic stem cell disorders: CUMC experience

Bone marrow transplantation from an HLA-identical sibling is increasingly used as a curative therapy for patients with hemopoietic stem cell disorders including acute leukemia, chronic myelogenous leukemia and severe aplastic anemia. Between March 1983 and March 1991, we performed 86 cases of allogeneic bone marrow transplantation (BMT) for the patients with hemopoietic stem cell disorders: 25 acute myelogenous leukemia (AML); 15 acute lymphoblastic leukemia (ALL); 20 chronic myelogenous leukemia (CML); and 26 severe aplastic anemia (SAA). Ten out of 25 AML are in disease free survival (DFS). The causes of death were recurrence of leukemia (12), acute GVHD (3), sepsis (1) and veno-occlusive disease (1). Nine of 15 ALL are in unmaintained remission. Thirteen out of 20 CML are in DFS. Among 26 SAA, 21 are enjoying DFS, but 1 died of engraftment failure, 3 of graft rejection followed by cytomegalovirus (1) and aspergillus pneumonia (1). Comparing the survival between standard [less than or equal to CR1: 9/14 (64%)] and high risk [greater than or equal to CR1: 1/11 (9%)] AML, our data suggest that preparative regimen for high risk AML was not potent enough to eradicate the minimal residual disease in advanced AML. Although our cases are limited and the follow-up period is short, our result of ALL [overall: CCR (60%), standard risk (adult less than or equal to CR1, children less than or equal to CR2; 8/11 (73%) and high risk; 1/4 (25%)] and CML [overall: 65%, CP; 9/10 (90%), AP; 4/6 (67%), BP; 0/4 (0%)] are optimistic. It is of our interest that the incidence of death related with IP (1/33: 3%) and with AGVHD 94/33: 12%) were much less than that of other's observation but the explanation for this still remains to be clear.

[Is permanent survival of kidney allograft receivers in weak histo-incompatible combinations dependent on enhancement?]

To study the immunological status of indefinitely surviving recipients of histocompatible (minor histoincompatible) allografts we transplanted Fi or (Fi x LEW)F1-kidneys to LEW-rats. At the same time bilateral nephrectomy was performed. To examine the cellular immune response we carried out local GvHR, microcytotoxicity assay and allorosette-formation test with recipient cells. We also studied lymphocytotoxins in the serum of recipients. To detect a blocking serum factor we used allorosette-formation inhibition test and microcytotoxicity assay. A blocking serum factor could not be found. In spite of stimulation with donor specific skin graft the cellular immune response of prolonged surviving recipients was inhibited. Our results suggest that prolonged survival of minor histoincompatible renal allograft recipients was caused by suppression of cellular immune response.

Detection of serum-blocking factors by inhibition of allorosette formation in rats with long-surviving renal allografts following short-term postoperative ALS treatment

Thirty-nine (LEW x BN)F1 kidneys were transplanted to LEW rats. Twenty-four untreated recipients survived for a mean time of 16.1 +/- 1.7 days (group 1). Fifteen recipients received 4 ml of antilymphocytic serum per rat (group 3). In the last group 10 recipients survived for more than 4 months. The spleen cells of these permanently surviving 10 rats were obtained by splenectomy and used in a graft-versus-host assay, and this assay showed that the reactivity of these cells was normal. Following splenectomy the animals were given an (LEW x BN)F1 skin allograft, followed 18 days by a second. After another 18 days (LEW x Buf)F1 "third party" skin allografts were transplanted to the same animals. Animals of group 2 rejected their first grafts with a mean survival time of 12.2 +/- 1.2 days, whereas the second grafts were rejected normally as were the third party grafts. Attempts were made to detect lymphocytotoxic antibodies and haemagglutinins before and after the transplantation of skin grafts and none could be found up to day 53. The sera of group 2 inhibited allorosette formation by 38%. This serum-blocking factor was donor specific. It is probable that the survival of the kidney transplants following antilymphocytic serum treatment was brought about by the development of blocking antibodies.

[Treatment of comatose patients by extracorporeal hemoperfusion with activated charcoal]

Hemoperfusion with activated charcoal is indicated in intoxications and in hepatic comma because the charcoal absorbs toxic substances. Good results have been obtained so far with activated charcoal liver perfusion in barbiturate intoxications, but less satisfactory results in hepatic comma. The indication for perfusion should also be made in clinically hopeless cases. The principal complications with activated charcoal perfusion are a decrease in thrombocytes and microemboli of charchoal particles. These complications can be avoided by coating the charcoal particles. A flow-rate of 200-300 ml/min is best in humans because this flow-rate ist guaranteed by an AV shunt in the forearm.

[Immune status of indefinitely surviving rat renal allograft recipients after short course of ALS-treatment Detection of a serum blocking factor by allorosette formation inhibition test (author's transl)]

53 LBNF1 kidneys were grafted into L-rats. 24 untreated recipients served as control and survived 16.1 +/- 1.7 days. 14 recipients were treated with 4 ml alloantiserum (ADS) each, and the other 15 animals with 4 ml ALS each. 9 and 10 of these 14 and 15 animals survived for more than 4 months. We performed GvH-reaction with spleen cells of these 19 animals. It showed normal cellular immune response. After splenectomy first donor specific skin was transplanted, 18 days later second skin of same origin (LBNF1) and 18' days after third party skin (LBufF1). The first grafts survived 13.1 +/- 1.9 days in the recipients of ADS treatment and 12.2 +/- 1.2 days in the recipients of ALS. Second skin grafts were rejected delayed in the former recipients as the first grafts, in the later more accelerated than the first grafts. The third grafts survived as the controls. Before and after skin grafting we could not detect lymphocytotoxin and hemagglutinin. The sera of animals with ADS therapy inhibited the spontaneous allorosette formation to 46.0 +/- 4.4% and of ALS therapy 37.7 +/- 9.2%. Our results suggest that after ALS treatment blocking antibodies were produced in the recipients and they cause the enhancement of kidney allograft.

Active enhancement of rat kidney allografts. Effect of pretreatment with prednisolone and donor-specific antigen

(Lewis x Brown Norway) F1 hybrid rat kidney allografts were transplanted to bilaterally nephrectomized Lewis recipients pretreated in various ways. The mean survival time of untreated controls was 16.1 +/- 1.7 days. All rats pretreated with 1.67 g/kg of semi-soluble Brown Norway spleen extract and 5 mg/kg of prednisolone on days 15, 8, and 1 before transplantation survived indefinitely. Pretreatment with semi-soluble or soluble extract alone prolonged survival modestly (36.5 +/- 13.6 and 30.8 +/- 5.6 days, respectively), but the former induced indefinite survival in two of eight animals. Prednisolone on its own failed to bring about prolongation of survival and the combined use of soluble extract and prednisolone did not reveal a synergistic effect. Cytotoxic antibody titres in animals showing indefinite survival were very low, and there was no correlation between antibody titres and prolonged survival. It is assumed that the pretreatment with semi-soluble extract and prednisolone inhibited the formation of cytotoxic antibodies as well as cell-mediated immunity, and encouraged the formation of enhancing antibodies. To study the cellular and humoral reactivity of five prolonged survived kidney recipients, 1st and 2nd donor-specific skin grafts were carried out. The humoral and cell-mediated responses were somewhat delayed in these recipients but otherwise normal except for the absence of the second-set phenomenon.