Evaluation of phosphatidylserine-dependent antiprothrombin antibody testing for the diagnosis of antiphospholipid syndrome: results of an international multicentre study.

Objective A task force of scientists at the International Congress on Antiphospholipid Antibodies recognized that phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) might contribute to a better identification of antiphospholipid syndrome (APS). Accordingly, initial and replication retrospective, cross-sectional multicentre studies were conducted to ascertain the value of aPS/PT for APS diagnosis. Methods In the initial study (eight centres, seven countries), clinical/laboratory data were retrospectively collected. Serum/plasma samples were tested for IgG aPS/PT at Inova Diagnostics (Inova) using two ELISA kits. A replication study (five centres, five countries) was carried out afterwards. Results In the initial study ( n = 247), a moderate agreement between the IgG aPS/PT Inova and MBL ELISA kits was observed ( k = 0.598). IgG aPS/PT were more prevalent in APS patients (51%) than in those without (9%), OR 10.8, 95% CI (4.0-29.3), p < 0.0001. Sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratio of IgG aPS/PT for APS diagnosis were 51%, 91%, 5.9 and 0.5, respectively. In the replication study ( n = 214), a moderate/substantial agreement between the IgG aPS/PT results obtained with both ELISA kits was observed ( k = 0.630). IgG aPS/PT were more prevalent in APS patients (47%) than in those without (12%), OR 6.4, 95% CI (2.6-16), p < 0.0001. Sensitivity, specificity, LR + and LR- for APS diagnosis were 47%, 88%, 3.9 and 0.6, respectively. Conclusions IgG aPS/PT detection is an easily performed laboratory parameter that might contribute to a better and more complete identification of patients with APS.

Lymphotropic hepatitis C virus has an interferon-resistant phenotype.

Hepatitis C virus (HCV) infects and associates with B cells, leading to abnormal B-cell activation and development of lymphoproliferative and autoimmune disorders. This immune perturbation may in turn be associated with the resistance of HCV against the host immune system. The objective of this study was to analyse the effects of HCV infection of B cells on the efficacy of interferon (IFN)-based therapy. The study enrolled 102 patients with chronic hepatitis C who were treated with pegylated IFN plus ribavirin. HCV RNA titres in B cells were compared in patients with rapid viral responder (RVR) vs non-RVR, sustained viral responder (SVR) vs non-SVR and null viral responder (NVR) vs VR. The levels of HCV RNA in B cells were significantly higher in non-RVR, non-SVR and NVR groups. Association between the therapy outcome and the positive B-cell HCV RNA was also investigated in relation to other known viral and host factors. Multivariable analyses showed that the positive B-cell HCV RNA and the minor single-nucleotide polymorphism near the IL28B gene (rs8099917) were independent factors associated with NVR in patients infected with HCV genotype 1. When these two factors were combined, the sensitivity, specificity, positive and negative predictive values for NVR were 92.3%, 98.2%, 92.3% and 98.2%, respectively. Genotype 1 and the presence of one or no mutations in the IFN-sensitivity determining region were associated with higher levels of B-cell HCV RNA. B-cell-tropic HCV appears to have an IFN-resistant phenotype. B-cell HCV RNA positivity is a predictive factor for resistance to IFN-based therapy.

Successful therapeutic use of a single-dose of rituximab on relapse in adults with minimal change nephrotic syndrome.

Minimal change nephrotic syndrome (MCNS) usually is considered to have a good renal prognosis, but the frequency of relapses is a therapeutic challenge to physicians. The treatment of patients with multiple relapses remains a matter of controversy, because few controlled studies are available. We report the case of a 25-year-old man who experienced relapses of MCNS. Single-dose rituximab therapy (total dose 500 mg) was given during the fourth relapse. Complete remission occurred 10 days later, when no CD19/20-positive B cells were detected in the blood. This the first report of efficacy of single-dose rituximab therapy to treat multi-relapsing MCNS in an adult patient.

Crystal structure of a plant ribonuclease, RNase LE.

Ribonuclease LE (RNase LE) from cultured tomato (Lycopersicon esculentum) cells is a member of the RNase T(2) family showing broad base specificity. The crystal structure of RNase LE has been determined at 1.65 A resolution. The structure consists of seven alpha-helices and seven beta-strands, belonging to an alpha+beta type structure. Comparison of the structure of RNase LE with that of RNase Rh, a microbial RNase belonging to the RNase T(2) family, reveals that while the overall folding topologies are similar to each other, major insertions and deletions are found at the N-terminal regions. The structural comparison, an amino acid sequence alignment of the RNase T(2) enzymes, and comparison of the disulfide-bonding pattern of these enzymes show that the structure of RNase LE shown here is the basic framework of the animal/plant subfamily of RNase T(2) enzymes (including a self-incompatibility protein called S-RNase), and the structure of RNase Rh is that of the fungal subfamily of RNase T(2) enzymes (including RNase T(2)). Subsequently, we superposed the active-site of the RNase LE with that of RNase Rh and found that (1) His39, Trp42, His92, Glu93, Lys96, and His97 of RNase LE coincided exactly with His46, Trp49, His104, Glu105, Lys108, and His109, respectively, of RNase Rh, and (2) two conserved water molecules were found at the putative P(1) sites of both enzymes. These facts suggest that plant RNase LE has a very similar hydrolysis mechanism to that of fungal RNase Rh, and almost all the RNase T(2) enzymes widely distributed in various species share a common catalytic mechanism. A cluster of hydrophobic residues was found on the active-site face of the RNase LE molecule and two large hydrophobic pockets exist. These hydrophobic pockets appear to be base binding sites mainly by hydrophobic interactions and are responsible for the base non-specificity of RNase LE.

Usefulness of intraoperative diagnosis of hepatic tumors located at the liver surface and hepatic segmental visualization using indocyanine green-photodynamic eye imaging.

BACKGROUND: To improve the diagnostic accuracy for hepatic tumors on the liver surface, we investigated the usefulness of an indocyanine green-photodynamic eye (ICG-PDE) system by comparison with Sonazoid intraoperative ultrasonography (IOUS) in 117 patients. Hepatic segmentation by ICG-PDE was also evaluated. METHODS: ICG was administered preoperatively for functional testing and images of the tumor were observed during hepatectomy using a PDE camera. ICG was injected into portal veins to determine hepatic segmentation. RESULTS: Accurate diagnosis of liver tumors was achieved with ICG-PDE in 75% of patients, lower than with IOUS (94%). False-positive and false-negative diagnosis rates for ICG-PDE were 24% and 9%, respectively. New small HCCs were detected in 3 patients. The ICG fluorescent pattern in tumors was strong staining in 41%, weak staining in 13%, rim staining in 20% and no staining in 26%. Hepatocellular carcinoma predominantly showed strong staining (61%), while rim staining predominated in cholangiocellular carcinoma (60%) and liver metastasis (55%). Hepatic segmental staining was performed in 28 patients, proving successful in 89%. CONCLUSION: ICG-PDE is a useful tool for detecting the precise tumor location at the liver surface, identifying new small tumors, and determining liver segmentation for liver resection.

A new method for studying the binding of human IgE to CD23 and the inhibition of this binding.

CD23, a low-affinity receptor for IgE (Fc epsilonRII), is a type II membrane-bound glycoprotein expressed on many hematopoietic cells, particularly activated B-cells. CD23 binds to IgE at a domain homologous to Ca2+-dependent (C-type) animal lectin. This paper describes a binding assay by which only the specific binding of IgE to CD23 expressed on Epstein-Barr virus (EBV)-transformed B-cell line, L-KT9 cells, can be detected. This assay is useful in the search for CD23 ligands among many chemical compounds, because it is easily carried out and does not require the use of any radiolabeled reagents. Using the assay, we investigated the inhibition of IgE binding to CD23 by fucose-1-phosphate which has been reported to inhibit the binding of sCD23 to IgE [Delespesse, G., Sarfati, M., Wu, C.Y., Fournier, S., Letellier, M., 1992. The low affinity receptor for IgE. Immunol. Rev. 125, 77.] and the binding of CD23 to CD21 [Pochon, S., Graber, P., Yeager, M., Jansen, K., Bernard, A.R., Aubry, T.-P., Bonnefoy, J.-Y., 1992. Demonstration of second ligand for the low affinity receptor for immunoglobulin E (CD23) using recombinant CD23 reconstituted into flourescent liposomes. J. Exp. Med. 176, 389.]. Although both alpha- and beta-L-fucose-l-phosphate/di(cyclohexylammonium) salt decreased the extent of IgE binding to CD23, the inhibitory effects were not due to alpha- or beta-L-fucose-1-phosphate but to cyclohexylamine. The inhibitory effect of cyclohexylamine was dose dependent and the effect was decreased when inhibition tests were carried out in the presence of a 10-fold excess of IgE. These results suggest that cyclohexylamine specifically interacts with the binding of CD23 and IgE.

Tubby-like protein 1 as an autoantigen in cancer-associated retinopathy.

Cancer-associated retinopathy (CAR) is a rare paraneoplastic syndrome that is characterized by retinal degeneration. Two cDNA clones, recoverin and tubby-like protein 1 (TULP1), were isolated from a human retinal cDNA library by using serum from a CAR patient as the probe. Both recoverin and TULP1 are retina-specific protein, and TULP1 is a member of tubby gene family. A determination of the recognized amino acid sequence of TULP1 by the patient serum and immunohistochemical studies on the distribution of TULP1 in the retina were done in this study.

Caspaselike proteases activated in apoptotic photoreceptors of Royal College of Surgeons rats.

PURPOSE: To study the role of caspase-like proteases, especially roles of more extensively characterized caspase-1 and caspase-2, in apoptotic photoreceptor cell degeneration in Royal College of Surgeons (RCS) rats. METHODS: Both RCS and Sprague-Dawley rats were used. Cryosections of the retinas at various postnatal times were immunostained with antibodies against caspase-1 (interleukin-1beta-converting enzyme, ICE) and caspase-2 (Nedd2/Ich-1). Double staining with TdT-dUTP terminal nick-end labeling (TUNEL), propidium iodide, and the antibodies was also performed. To evaluate the time course of protein expression, western blot analysis was carried out. The temporal profile of caspase-like protease activity was studied using a fluorogenic tetrapeptide substrate, acetyl-tyrosyl-valyl-alanyl-aspartic acid alpha (4-methyl-coumaryl-7-amide) (Ac-YVAD-MCA). Intravitreal injection of a caspase-1 inhibitor, acetyl-tyrosyl-valyl-alanyl-aspartic-aldehyde (Ac-YVAD-CHO), at postnatal days 21 (P21) and P26 was performed to see if this caused a decrease in apoptotic cell number at P28. RESULTS: TUNEL-positive photoreceptors of RCS rats stained strongly with antibodies against caspase-1 and caspase-2. Double staining studies revealed that caspase-1 and caspase-2 were coexpressed in apoptotic cells. Western blot analysis showed that active forms of caspase-1-like and caspase-2-like proteases were upregulated at P28, concurrent with the peak in TUNEL-positive cells. The enzymatic activity of caspase-1-like protease was elevated in RCS rat retinas at P28, and the inhibitor of caspase-1 transiently reduced the number of the apoptotic photoreceptors. CONCLUSIONS: Activation of caspase-like proteases plays an important role in photoreceptor apoptosis of RCS rats.

Alteration of proto-oncogenes during apoptosis in the oral squamous cell carcinoma cell line, SAS, induced by staurosporine.

Staurosporine (ST) has been reported to induce apoptosis in many kinds of cultured cells. The pathway of the apoptosis induced by ST is still not clear. Certain proto-oncogene expressions have been shown to be involved in the apoptotic pathway. The present study characterized apoptosis induced by ST in the oral squamous cell carcinoma cell line, SAS, focusing on the alteration of proto-oncogene expression. SAS showed typical apoptotic features upon exposure to ST. We compared the level of gene expression in apoptosis induced by ST with that by withdrawal of serum, which is a common system to induce apoptosis. By RT-PCR analysis, ST-induced apoptosis showed c-fos and c-jun up-regulation, whereas serum withdrawal-induced apoptosis showed c-jun up-regulation and the same levels of p21/waf-1 and c-myc. These results indicate that ST can rapidly induce apoptosis in SAS, possibly via a c-fos and c-jun pathway.

Slow spin relaxation of Rb atoms confined in glass cells filled with dense 4He gas at 1.85 K

At temperatures below 2.1 K, long-lived gaseous Rb atoms in glass cells have been generated with a simple method: irradiating the cells, containing 4He gas and Rb metal, with a cw laser. The obtained atomic Rb density ( approximately 10(8) cm(-3)) decreases with a 1/e time constant of about 10 s at 1.85 K. We have performed optical pumping of the Rb atoms and measured the longitudinal electronic spin relaxation time at 1.85 K as well. For processes (such as Rb-He collisions) which do not remove the atomic Rb from the vapor, this relaxation time is found to be about 60+/-15 s.

Molecular cloning and characterization of a new neuron-specific homologue of rat polypyrimidine tract binding protein.

Cancer-associated retinopathy (CAR) is a rare form of retinal degeneration and also one of the paraneoplastic neurologic disorders. Sera of CAR patients usually contain high titers of antibodies against retinal proteins, and CAR is believed to be an autoimmune disease. Using serum from a CAR patient as a molecular probe, a homologue of the polypyrimidine tract-binding protein (PTB) was isolated from a cDNA library of rat neonatal retina. This homologue, named PTB-like protein (PTBLP), encodes a 532 amino acid residue protein and has 73.5 and 68.8% homology with PTB and with a regulator of differentiation 1, respectively. Functional domains in the PTB, such as nuclear localization signals and four RNA recognition motifs (RRMs), were highly conserved. The expression of PTBLP mRNA was observed in the retina and brain but not in liver, kidney, spleen, or lung. The expression of PTBLP protein in rat retina was distributed in most of the cells in the ganglion cell layer and some cells in the inner nuclear layer. The PTBLP protein was localized in the nuclei of these cells. These results suggest that PTBLP is a new member of the PTB gene family and a neuron-specific homologue.

Effects of dietary protein intake on renal function in humans.

The effects of an acute protein load on renal hemodynamic responses and plasma glucagon levels were investigated in 31 patients with biopsy proven chronic glomerulonephritis (24 cases) or chronic renal failure (6 cases). After baseline clearance measurements, the subjects ingested a high protein meal consisting of 1.2 to 1.5 g protein/kg body weight in the form of cooked beef followed by a second set of measurements. This acute protein load resulted in a rise of both creatinine and PAH clearances (from 86.5 +/- 6.0 ml/min to 98.3 +/- 7.1 ml/min and 531.1 +/- 59.1 ml/min to 688.9 +/- 72.9 ml/min, respectively). This was associated with an elevation of plasma glucagon levels from 104.6 +/- 7.9 pg/ml to 134.5 +/- 7.5 pg/ml. From these data we suggest that the augmentation of renal function following a high protein intake may be mediated by the simultaneous rise of plasma glucagon levels, and that the glucagon concentration in the portal vein rather than in the peripheral blood has a pivotal role in this setting.

Nitric oxide synthase I immunoreactivity in the macula densa of the kidney is angiotensin II dependent.

The present study was undertaken to clarify the mechanism of the regulation of nitric oxide synthase (NOS)-I in the macula densa of the kidney. We determined the changes in NOS-I immunoreactivity of the macula densa relevant to the changes in systemic blood pressure (BP) and the renin-angiotensin system. Rats received four different types of treatment, and kidney sections were immunohistochemically stained for renin, NOS-I, and NOS-III. Plasma renin activity (PRA) and angiotensin II (Ang II) concentration were determined by radioimmunoassay. In the low-salt group, PRA, plasma Ang II, and the number of renin and NOS-I positively stained areas in the juxtaglomerular apparatus (JGA) were all increased, while BP and NOS-III in the glomerular capillaries did not change. In the desoxycorticosterone acetate (DOCA)-salt group, in contrast to the elevation of BP, PRA, plasma Ang II, and all immunohistochemical parameters were decreased. In the Ang II infusion group, BP, plasma Ang II, and the number of NOS-I positive glomeruli were increased, while PRA and renin staining were decreased. Administration of Ang II type 1 receptor (AT-1) antagonist TCV-116 significantly increased PRA, plasma Ang II, and the number of renin-positive glomeruli. However, BP, and NOS-I and NOS-III staining did not show any difference. These results clearly suggest that NOS-I in the macula densa changes in parallel with plasma Ang II, but not renin or systemic BP.

Optical coherence tomograghy to confirm early closure of macular holes.

PURPOSE: To report that optical coherence tomography as early as 24 hours after macular hole surgery shows anatomic configuration of the closed macular holes. METHOD: In a prospective study, seven eyes of seven consecutive patients with stage 3 or 4 idiopathic macular hole underwent surgery. Optical coherence tomography was performed preoperatively and at 24, 48, and 72 hours after the surgery. RESULTS: Optical coherence tomography images could be obtained on four out of the seven eyes at 24 hours after surgery. These images showed anatomic configuration of the closed macular holes. Surgical success was confirmed in all of the eyes when the gas was completely absorbed. CONCLUSION: Optical coherence tomography revealed anatomic configuration of surgically closed macular holes within 24 hours after successful surgery.

A new delivery system for 5-fluorouracil using prodrug and converting enzyme.

AIMS: To evaluate a new delivery system of 5-fluorouracil (5-FU) using 5-fluorocytosine (5-FC) as a prodrug and cytosine deaminase induced in vitro and in vivo. METHODS: Fibroblastic cells from rabbit Tenon's capsule were cultured. The cells were exposed to 5-FU and 5-FC with or without cytosine deaminase induced by recombinant adenovirus. In the in vitro study, cell proliferation and DNA synthesis were assessed by MTS, BrdU assay. The effect of 5-FC removal after the treatment of 5-FC and cytosine deaminase induction was also assayed. In the in vivo study cells with or without cytosine deaminase induction were transplanted into the subconjunctival space of mice, followed by eye drops of 1000 microg/ml of 5-FC three times a day. The mice were sacrificed at days 1, 5, and 10, then the cells transplanted were evaluated. RESULTS: Cell proliferation was inhibited by exposure to 5-FU in a dose dependent manner; however, up to 1000 microg/ml of 5-FC did not affect cell proliferation. Cell proliferation was inhibited by exposure to 5-FC in a time dependent manner with induction of cytosine deaminase following infection of recombinant adenovirus. When 5-FC was removed 3 or 6 days after the treatment, the cells grew again. The effect was reproduced in the in vivo model of subconjunctival cellular proliferation although 5-FC was administrated as eye drops. There were no cases with corneal erosion. CONCLUSION: Cell proliferation was inhibited by co-exposure of 5-FC and cytosine deaminase. This new delivery system may merit controlled delivery of 5-FU after filtering surgery.

Non-X-linked hyper-IgM syndrome with systemic lupus erythematosus.

A 24-year-old woman had suffered from recurrent bacterial infections and clinical manifestations of systemic lupus erythematosus (SLE). Laboratory findings disclosed an elevated level of serum IgM, markedly decreased IgG, IgA, IgD and IgE levels, and low levels of serum complement. Both the CD40 and CD40 ligands appeared to be normally expressed. Assays of in vitro immunoglobulin production by lymphocytes showed that IgM was produced normally and that IgE but not IgG or IgA production was rescued by signaling through CD40 on B cells. The proliferative response of lymphocytes to phobol ester was markedly decreased, suggesting some impairment of signal transduction in the patient's lymphocytes.

Erythrina cristagalli lectin-reactive alpha-fetoprotein-E2: a marker of hepatocellular carcinoma and other malignancies.

A newly isolated lectin Erythrina cristagalli (ECL) was tested for separation of human alpha-fetoprotein (AFP) glycoforms by affinity electrophoresis at 0.5 mg/ml and separated AFP bands were detected by antibody-affinity blotting. Three AFP bands, AFP-E1, AFP-E2 and AFP-E3 in order of increasing affinity, were obtained. Sera from control patients with chronic hepatitis and cirrhosis gave a major band of AFP-E1 and a minor or trace band of AFP-E2 (3.4 +/- 2.3%), while those from patients with mostly advanced hepatocellular carcinomas had increased proportions of AFP-E2 band (16.6 +/- 10.2%). With a cutoff level of 8% (mean + 2SD of AFP-E2 for controls), the sensitivity for hepatocellular carcinoma was 72% at a specificity of 100%. Gastrointestinal tumors had much higher percentages of AFP-E2 and occasionally positive AFP-E3. Most of the yolk sac tumors examined showed AFP-E3 in addition to AFP-E2, although AFP-E3 was a minor band. Thus, AFP-E2 is potentially a clinically useful marker for differentiation of increased AFP in hepatocellular carcinoma and other malignancies from that in precancerous chronic hepatitis or cirrhosis.

Influence of spironolactone on neonatal screening for congenital adrenal hyperplasia.

AIM: To determine if the diuretic spironolactone cross reacts with 17alpha-hydroxyprogesterone (17OHP) in an enzyme linked immunosorbent assay (ELISA) kit used for the mass screening of congenital adrenal hyperplasia. METHODS: Concentrations of 17OHP on a blood filter paper disc were measured using an ELISA kit (kit C-7: ENZAPLATE N-17alpha -OHP-7; Chiron, Tokyo, Japan). The cross reactivity of spironolactone and its metabolites with 17OHP was determined. The concentrations of spironolactone and its metabolites in blood were measured using HPLC (high performance liquid chromatography). RESULTS: Spironolactone cross reacted with 17OHP using kit C-7 (0.01%), by increasing 17OHP concentration in a dose dependent manner. The blood concentration of spironolactone and its metabolites was nearly 900 ng/ml, high enough to show an additive effect on the 17OHP concentration. About 12% of the false positive cases screened using the kit were due to the administration of spironolactone. CONCLUSIONS: Spironolactone interferes with 17OHP concentrations, leading to false positive test results for CAH.

Metabolic conversion of alpha-keto valine to valine in patients with chronic renal failure.

Change in the metabolic conversion rate of alpha-keto valine to valine following oral administration of the analog of the essential amino acid (0.1 g/kgB.W.) is studied in six patients with chronic renal failure and five control subjects under low protein, low and normal energy intake diets. Diet I is composed of 105 kj (25 kcal)/kgB.W. energy and 0.6 g/kgB.W. protein, whereas Diet II is composed of 165 kj (40 kcal)/kgB.W. with the same amount of protein intake. As a result, an increase in plasma keto valine concentration is observed immediately after oral administration, followed by an increase in plasma valine concentration, implying that metabolic conversion of alpha-keto valine to valine occurs within a small amount of time. In addition, the conversion rate appears to be accelerated under Diet II. It is therefore suggested that reutilization of urea nitrogen with the ketoanalog under the low protein diet seems to be promoted under adequate energy intake.

[Anticancer susceptibility test method using general-purpose dissolved oxygen meter].

Drug susceptibility of cell can be rapidly measured by continuously monitoring its metabolic changes. We focused on respiration volume as a signal of metabolic change, and developed a new dissolved oxygen measuring system which can detect respiration volume of cells. The main feature of the system is the use of a new type bare oxygen electrode which can easily detect the changing rate of dissolved oxygen concentration. In this study, single type electrode was used to evaluate this rapid anticancer drug susceptibility test. The result obtained was almost equivalent to that with MTT method, which is a conventional method for susceptibility test of HL-60 to various kinds of anticancer drugs. We have also developed multi-type electrode plate with oxygen electrodes embedded in the bottom of 96-well plate, with which clinical evaluation of this method can be easily made.