Deformation of the stentless porcine valve scaffold enhances accelerated leaflet fibrosis and calcification in juvenile sheep

Stent mounting of xenografts induces a loss of mobility and reduces the effective valve orifice. By contrast, the higher surgical technical expertise required for stentless procedures is a major obstacle for many surgeons. To facilitate the insertion of the Toronto SPV (St Jude Medical Inc, St Paul, Minneapolis, MN) stentless aortic valve, we tried to alter the porcine design by lowering the invasive profile at the depth of the sinuses on both coronary sites. This technique could theoretically facilitate implantation of the modified stentless valve with an easygoing single-layer suture at the challenging subcoronary level and make it more attractive for the surgeon. The standard model was modified by lowering the profile at the depth of the sinuses on both coronary sites, whether by plication (in 3 specimens, one of each size) or excision (in 3 others) of the protruding porcine aortic wall at the nadir of each coronary sinus. Animal implants in juvenile sheep (6 standard Toronto versus 6 modified valves of 21, 23, and 25 mm) were studied for durability and biocompatibility for 3 to 6 months. All valves were evaluated by postoperative echocardiography and after explantation examined macroscopically, radiographically, histologically, and electron microscopically. The standard valves performed well, although at 6 months after implantation, marked fibrosis was found at the outflow parts with scattered calcifications, essentially in the porcine aortic wall. The leaflets remained mobile and contained scant mineralization. By contrast, the modified specimen showed markedly accelerated fibrosis and significant cusp calcifications at distance from the altered zones. Severe restriction of the mobility of the leaflets was visible 3 months after implantation in the juvenile sheep model. The more pronounced the deformation of the modified scaffold, the faster and more intense the degradation and calcification of the leaflets far from the altered zones (worse in the heavily deformed, plicated cusps). Because all valve types were prepared by identical preservation techniques, this study shows that loss of mobility by distortion of the natural scaffold induces early failure. It is extremely important to correct implantation of stentless valves to prevent early degeneration.

In situ nucleic acid detection of human telomerase in intrahepatic cholangiocarcinoma and its preneoplastic lesion

Human telomerase, an enzyme associated with cellular immortality and tumorigenesis, is expressed by most malignant tumor cells. Human telomerase consists of human telomerase RNA (hTR) and telomerase protein components. One of the latter has been cloned and was termed telomerase-associated protein 1 (TP1). Using an in situ hybridization method, expression of hTR and TP1 mRNA was surveyed in 20 cases of intrahepatic cholangiocarcinoma (ICC) (5 of them were associated with hepatolithiasis), 5 cases of hepatolithiasis alone and 6 normal livers. Biliary dysplasia, which is suspected as a preneoplastic lesion of ICC, was found in the biliary tree in all 5 ICC cases with hepatolithiasis and in 1 of 5 cases of hepatolithiasis alone. Normal colonic mucosa was used as positive control. In 17 (85%) of 20 ICC cases, hTR and TP1 mRNA were detected in carcinoma cells. There was no correlation between histological subtype of ICC and expression of hTR and TP1 mRNA. Biliary dysplasia was also positive for both RNA. These signals were mainly located in the cytoplasm of carcinoma and dysplastic cells, especially around their nuclei. The signals were homogeneously detected in the carcinoma, while their distribution was more or less heterogeneous in the dysplastic foci. These signals were not detected in nondysplastic biliary epithelia in hepatolithiasis and normal livers. It seems likely that almost all ICC acquired telomerase activities irrespective of histological subtype and more importantly that cellular immortalization has already occurred in biliary dysplasia and this lesion is already involved in the malignant progression of ICC.

Fas ligand-induced apoptosis of hepatocytes in natural killer cell leukaemia

Neoplastic natural killer (NK) cells overexpress Fas ligand (FasL), which may cause damage of Fas-bearing tissues. We report a patient with NK cell leukaemia who developed liver injury after pharyngitis. The NK leukaemic cells expressed functional FasL. In addition to soluble FasL, serum levels of interleukin-6 and interferon-gamma were increased dramatically when liver injury was aggravated. Moreover, hepatocytes expressed Fas and apoptotic hepatocytes were detected in the portal areas. These findings are consistent with the notion that inflammatory cytokines enhance the sensitivity to FasL and trigger apoptosis of hepatocytes in NK cell malignancies.

Neovascularization of the outermost area of herniated lumbar intervertebral discs

In 64 surgically treated herniated lumbar intervertebral discs, we performed histopathological studies of neovascularization in the outermost layer of the herniated mass in various types of hernia. We obtained specimens separately from the capsule tissue covering the herniated mass and the inner tip tissue of the herniated mass for comparison. Histologically, in most cases, the capsule tissue was the outermost layer of the annulus fibrosus or posterior longitudinal ligament, and the inner tip tissue was the nucleus pulposus. In the capsule tissue, newly formed small blood vessels were present in 73.4% of the total cases examined, regardless of the hernia type. However, the frequency and degree of such vessels in the tip tissue were significantly higher in hernias that perforated the posterior longitudinal ligament than in those that did not. When the intervertebral disc herniates, new blood vessels proliferate in the capsule of the hernial tissue. At the stage when the hernial capsule tissue is still present, these vessels were observed to have difficulty reaching the inner tip portion. These findings suggest that when the nucleus pulposus portion of the herniated mass perforates the posterior longitudinal ligament, it may be subject to a stronger neovascularization reaction.

Autoantibodies to FK506 binding protein 12 (FKBP12) in autoimmune diseases

Plasma from 126 patients with various autoimmune diseases and 118 healthy subjects were examined to determine the presence of autoantibodies to FKBP12, one of immunophilins. The frequency of IgG and/or IgM anti-FKBP12 autoantibodies detected by ELISA was as follows; SLE (15/39), SSc (11/27), CREST (4/7), RA (2/8), MCTD (0/5), Graves' disease (4/12), IDDM (2/6), PM/DM (0/3), MG (1/4), AIH (2/6), PBC (4/9), and healthy subjects (5/118). The specificity of the autoantibodies was demonstrated by absorption of the plasma samples with r-FKBP12 and other recombinant proteins. In immunoblotting, IgM anti-FKBP12 autoantibodies reacted with two bands of 12 and 24 kD, the latter representing the dimer. Anti-FKBP12 autoantibodies in some patients reacted more strongly with the dimer than the monomer, suggesting that FKBP12 may also exist as the dimer in vivo. The majority of anti-FKBP12 autoantibodies bound to two synthetic peptides corresponding to amino acid residues of FKBP12, Pro16 approximate to Tyr26 and Thr27 approximate to Phe46. These epitopes are phylogenetically well conserved and responsible for the binding to calcineurin and FK506. The autoantibodies inhibited pentamerization of FKBP12 with FK506, calcineurin, calmodulin, and Ca2+ in vitro. These data define the frequent occurrence of a novel set of autoantibodies to a cytosolic protein involved in the regulation of the immune response.

[Utility of the paraffin-embedded section method on the detection of estrogen receptor from breast cancer tissues--comparison of the paraffin-embedded section method (6F11 and 1D5) with frozen section (H222) and dextran-coated charcoal (DCC) ones]

From March 1988 to December 1990, we detected estrogen receptor (ER) from breast cancer tissues with the dextran-coated charcoal (DCC) method. From September 1990 to March 1998, we repeated the above with the frozen section method (cloneH222; DAINABOT). With the paraffin-embedded section method using two antibodies of anti-ER (clone6F11; NOVOCASTRA and clone 1D5; MBL), we examined the ER of the same 185 primary breast cancer tissues. We had already detected these tissues with the frozen section method, and we also applied the same procedure for the 43 primary breast cancer tissues which had already been detected with the DCC method. We compared these data. The positive rates of ER with DCC, H222, 6F11 and 1D5 were 49%, 53%, 53% and 52% respectively, which were within the reported range. The accuracy between H222 and 6F11 which was calculated as the percentage that were in positive and negative concordance by the two methods, was 88%. The accuracies between H222 and 1D5, between 6F11 and 1D5, between DCC and 6F11, between DCC and 1D5 were respectively 89%, 96%, 79%, and 77%. Although the accuracy between DCC and the paraffin-embedded section was not necessarily high, we obtained a higher concordance between the frozen and paraffin-embedded sections. The highest concordance existed between 6F11 and 1D5. The 30% of negative cases with DCC were positive with paraffin-embedded section. Among these methods of ER detection from breast cancer tissues, the paraffin-embedded section method seemed to be the most useful.

Cytogenetic alterations in pituitary adenomas detected by comparative genomic hybridization

Pituitary adenomas are benign monoclonal tumors that are either hormonally functional or nonfunctional. Although their histologic and immunocytologic characteristics have been studied extensively, cytogenetic studies are scarce. We have investigated the cytogenetic alterations and DNA ploidy patterns of 12 sporadic pituitary adenomas, including 2 growth-hormone-secreting tumors, 1 prolactinoma, and 9 nonfunctional adenomas, by comparative genomic hybridization (CGH) and laser scanning cytometry (LSC). CGH revealed that the mean number of sites of copy gain was significantly higher in functioning adenomas than in nonfunctioning tumors (P < 0.01). The most frequent change detected was loss of 13q (5 cases), with a minimal common overlapping region at 13q14. These findings suggest that a putative tumor suppressor gene on 13q14 may play an important role in the development of pituitary adenomas. DNA aneuploidy was detected by LSC in 3 of the 12 cases. The DNA aneuploid adenomas showed cytogenetic changes more frequently than did the DNA diploid tumors (P < 0.02).

Sensitive measurement of serum abnormal prothrombin (PIVKA-II) as a marker of hepatocellular carcinoma

BACKGROUND/AIMS

The usefulness of abnormal prothrombin (PIVKA-II) for diagnosis of small HCC has been limited by its low sensitivity, despite a high specificity.

METHODOLOGY

The serum concentration of PIVKA-II was determined by using a new sensitive enzyme immunoassay (EIA) kit in patients with hepatocellular carcinoma (HCC), liver cirrhosis (LC), or chronic hepatitis (CH) and normal controls (NC). alpha-Fetoprotein (AFP) was simultaneously determined in same patients.

RESULTS

This kit has made it possible to detect low concentrations of PIVKA-II in the NC. The serum PIVKA-II concentration (mean +/- SE) was 15.7 +/- 1.1 mAu/ml, 16.1 +/- 2.0 mAu/ml, 26.3 +/- 7.2 mAu/ml and 5420.3 +/- 3960.0 mAu/ml in NC, CH, LC and HCC, respectively. Among 106 patients with HCC, 74 patients (69.8%) were positive for PIVKA-II (> or = 40 mAu/ml), while only 9 patients out of 68 patients with LC were positive (13.2%) and only 2 out of 90 patients with CH were positive (2.2%). No significant correlation was observed between AFP and PIVKA-II levels. With combined assay of AFP and PIVKA-II, the positive rate for HCC was increased to 78.3%. Among 14 patients with HCC < 20 mm in diameter. 7 were positive for PIVKA-II, and 6 out of 10 patients with HCC between 20 and 30 mm in diameter were positive for PIVKA-II. There was a correlation between tumor size and the PIVKA-II level.

CONCLUSIONS

Determination of PIVKA-II by this new EIA kit could be useful for the diagnosis of HCC, especially combined with determination of AFP.

In situ nucleic acid detection of PDC-E2, BCOADC-E2, OGDC-E2, PDC-E1alpha, BCOADC-E1alpha, OGDC-E1, and the E3 binding protein (protein X) in primary biliary cirrhosis

The characteristic serological feature of primary biliary cirrhosis (PBC) is the presence of antimitochondrial antibodies (AMAs), and the major proteins recognized by AMAs are subunits of the 2-oxo acid dehydrogenase complexes (2-OADC), including the E2 components of the pyruvate dehydrogenase complex (PDC), the 2-oxo-glutarate dehydrogenase complex (OGDC), the branched-chain 2-oxoacid dehydrogenase complex (BCOADC), the E3 binding protein (E3BP or protein X) and the E1a component of mammalian PDC. Previous work has postulated that either E3BP, or a molecule cross-reactive with the PDC-E2 molecule, is uniquely expressed on the surface of biliary epithelial cells in PBC. To address this issue, we performed in situ hybridization for all of the major 2-OADC components at the mRNA level, including PDC-E2, BCOADC-E2, OGDC-E2, PDC-E1a, BCOADC-E1a, OGDC-E1, and E3BP using 13 PBC and 9 control livers using 7 mitochondrial antisense probes. In both PBC and controls, the expression of all 2-OADC component mRNA studied herein were found in hepatocytes and infiltrating mononuclear cells, without significant differences. Interestingly, however, despite published data on immunohistochemical staining, interlobular bile ducts including the injured bile ducts in PBC were generally negative or only faintly positive, with the exception of 1 bile duct in 1 of 13 cases of PBC and 1 of 9 control liver specimens. Moreover, confocal microscopic examination and image analysis revealed that the mRNA signal intensity of each of the 2-OADC components in the bile ducts of PBC was relatively lower in comparison with control liver diseases. These data suggest that continuous enhanced synthesis of the 2-OADC components is not likely to be occurring in the biliary epithelial cells in PBC, and that an increase of PDC-E2 or E3BP immunoreactivity in PBC is caused by exogenous imported or cross-reactive molecules.

Genetic alterations in pediatric medulloblastomas detected by comparative genomic hybridization

Children with medulloblastomas show diverse clinical courses even when receiving similar treatments. In this study, comparative genomic hybridization, which allows the detection of losses and gains in DNA copy number along the entire genome, was used to investigate the genetic alterations in 6 cases of medulloblastoma with adequate follow-up periods and similar treatments, and in a medulloblastoma cell line. In the cell line, the number of aberrations was the highest of all samples examined. In 6 clinical samples, frequently altered regions (more than 3 cases) observed in all medulloblastomas were gains of 7q and 17q (4 cases each), and of 2p, 2q and 7p (3 cases each). High-grade amplification was observed at the loci 8q, 17q and 21q, each in a single case. The case with the most favorable outcome 9 years after surgery had the smallest number of chromosomal changes among the cases examined. Our results may indicate that further acquisition of genetic alterations detected by comparative genomic hybridization are associated with unfavorable prognosis in patients with medulloblastomas.

Pharmacological properties of J-104132 (L-753,037), a potent, orally active, mixed ETA/ETB endothelin receptor antagonist

J-104132 [(+)-(5S,6R, 7R)-2-butyl-7-[2-((2S)-2-carboxypropyl)-4-methoxyphenyl]-5-(3, 4-methylenedioxyphenyl)cyclopenteno[1,2-b]pyridine-6-carboxylic; also referred to as L-753,037] is a potent, selective inhibitor of ETA and ETB endothelin (ET) receptors (e.g., Ki: cloned human ETA = 0.034 nM; cloned human ETB = 0.104 nM). In both ligand-binding and isolated tissue preparation protocols, the inhibition of ET receptors with J-104132 is reversible and competitive. In vitro, J-104132 is a potent antagonist of ET-1-induced accumulation of [3H]inositol phosphates in Chinese hamster ovary cells stably expressing cloned human ETA receptors (IC50 = 0.059 nM), ET-1-induced contractions in rabbit iliac artery (pA2 = 9.70) and of BQ-3020-induced contractions in pulmonary artery (pA2 = 10.14). J-104132 is selective for ET receptors because it had no effect on contractions elicited by norepinephrine or KCl in the vascular preparations. The in vivo potency of J-104132 was assessed using challenges with exogenous ET-1. In conscious mice, 5 nmol/kg i.v. ET-1 causes death. Pretreatment with J-104132 prevents the lethal response to ET-1 when administered i.v. (ED50 = 0.045 mg/kg) or p.o. in fed animals (ED50 = 0.35 mg/kg). In conscious, normotensive rats, pressor responses to 0.5 nmol/kg i.v. ET-1 are inhibited by J-104132 after i.v. (0.1 mg/kg) or p.o. (1 mg/kg) administration. In anesthetized dogs, ET-1 was administered directly into the renal artery or brachial artery to generate dose-response (blood flow) curves, and the inhibitory potency of J-104132 (i.v. infusion) was quantified. J-104132 produced greater than 10-fold shifts in the ET-1 dose-response curves at 0.03 mg/kg/h (renal) and 0.3 mg/kg/h (brachial). Oral bioavailability of J-104132 in rats was approximately 40%. These studies indicate that J-104132 is a selective, potent, orally active antagonist of both ETA and ETB receptors and is an excellent pharmacological tool to explore the therapeutic use of a mixed ETA/ETB receptor antagonist.

High mobility group (HMG) non-histone chromosomal proteins HMG1 and HMG2 are significant target antigens of perinuclear anti-neutrophil cytoplasmic antibodies in autoimmune hepatitis

BACKGROUND

High mobility group (HMG) non-histone chromosomal proteins HMG1 and HMG2 have been identified as novel antigens of perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCAs), and the existence of anti-HMG1 and anti-HMG2 antibodies in a population of patients with ulcerative colitis has been reported.

AIMS

To investigate whether HMG1 and HMG2 are target antigens for p-ANCAs in autoimmune hepatitis (AIH).

PATIENTS

Serum samples from 28 patients with AIH, 44 patients with primary biliary cirrhosis (PBC), 27 patients with chronic hepatitis C, and 23 patients with chronic hepatitis B were tested.

METHODS

ANCAs were detected by routine indirect immunofluorescence (IIF). Anti-HMG1 and anti-HMG2 antibodies were assayed by enzyme linked immunosorbent assay.

RESULTS

p-ANCAs were detected in 89% (25/28) of patients with AIH, 36% (16/44) of patients with PBC, 11% (3/27) of patients with chronic hepatitis C, and 13% (3/23) of patients with chronic hepatitis B. Anti-HMG1 and/or anti-HMG2 antibodies were detected in 89% (25/28) of patients with AIH, 70% (31/44) with PBC, 26% (7/27) with chronic hepatitis C, and 9% (2/23) with chronic hepatitis B. In AIH, anti-HMG1 and/or anti-HMG2 antibodies were detected in 96% (24/25) of p-ANCA positive patients. The p-ANCA staining pattern detected by IIF using sera from patients with AIH disappeared or decreased in titre after preincubation with a mixture of HMG1/HMG2. The presence and titres of those antibodies in AIH correlated significantly with those of p-ANCA, but not with those of anti-nuclear antibody or anti-smooth muscle antibody.

CONCLUSIONS

HMG1 and HMG2 are significant target antigens of p-ANCA in AIH.

Biclonal lymphoplasmacytic immunocytoma associated with Crohn's disease

A 33-year-old man with a 4-year history of Crohn's disease presented with marked ascites and an abdominal tumor. Two M-protein peaks, immunoglobulin (Ig) G-kappa and IgA-kappa, were detected in the serum. Neoplastic lymphoplasmacytic cells were infiltrated in the bone marrow and ascites. Histological examination of the abdominal tumor showed marked proliferation of lymphoplasmacytic cells that were positive for either IgG or IgA. Moreover, DNA sequences of the expressed IgG and IgA genes were different in the complementarity-determining region 3. These results suggest that chronic inflammation in Crohn's disease contributes to the simultaneous development of biclonal lymphoplasmacytic immunocytoma of the small intestine.

Humanized anti-HM1.24 antibody mediates myeloma cell cytotoxicity that is enhanced by cytokine stimulation of effector cells

To develop a new immunotherapy for multiple myeloma, we have generated a monoclonal antibody (MoAb) that detects a human plasma cell-specific antigen, HM1.24. Our previous study has shown that mouse anti-HM1.24 MoAb inhibits the proliferation of human myeloma cells implanted into severe combined immunodeficiency mice. In this report, we evaluated the antitumor activity of the humanized anti-HM1.24 MoAb (IgG1kappa), which was constructed by grafting the complementarity-determining regions. In contrast to the parent mouse MoAb, humanized anti-HM1.24 MoAb mediated antibody-dependent cellular cytotoxicity (ADCC) against both myeloma cell lines and myeloma cells from patients in the presence of human peripheral blood mononuclear cells (PBMCs). The PBMCs from untreated myeloma patients exhibited ADCC activity as efficiently as those of healthy donors. Although decreased ADCC activity of PBMCs was observed in patients who responded poorly to conventional chemotherapy, it could be significantly augmented by the stimulation with interleukin-2 (IL-2), IL-12, or IL-15. There was a strong correlation between the percentage of CD16(+) cells and ADCC activity in the PBMCs of myeloma patients. Moreover, peripheral blood stem cell collections from myeloma patients contained higher numbers of CD16(+) cells than PBMCs and exhibited ADCC activity that was enhanced by IL-2. These results indicate that humanized anti-HM1.24 MoAb has potential as a new therapeutic strategy in multiple myeloma and that treatment of effector cells with immunomodulating cytokines can restore the effect of humanized anti-HM1.24 MoAb in patients with diminished ADCC activity.

Isolation and characterization of CA XIV, a novel membrane-bound carbonic anhydrase from mouse kidney

Carbonic anhydrase (CA) is involved in various physiological processes such as acid-base balance and transport of carbon dioxide and ions. In this study, we have succeeded in the isolation of a novel CA from the mouse kidney by use of the signal sequence trap method. It is a 337-amino acid polypeptide with a calculated molecular mass of 37.5 kDa, consisting of a putative amino-terminal signal sequence, a CA domain, a transmembrane domain, and a short hydrophilic carboxyl terminus, which we designated CA XIV. The CA domain of CA XIV is highly homologous with those of known CAs, especially extracellular CAs including CA XII, IX, VI, and IV. The expression study of an epitope-tagged protein has suggested that CA XIV is located on the plasma membrane. When expressed in COS-7 cells, CA XIV exhibits CA activity that is predominantly associated with the membrane fraction. By Northern blot analysis, the gene expression of CA XIV is most abundant in the kidney and heart, followed by the skeletal muscle, brain, lung, and liver. In situ hybridization has revealed that, in the kidney, the gene is expressed intensely in the proximal convoluted tubule, which is the major segment for bicarbonate reabsorption and also in the outer border of the inner stripe of the outer medulla. In conclusion, we have cloned a functional cDNA encoding a novel membrane-bound CA. This study will bring new insights into our understanding of carbon dioxide metabolism and acid-base balance.

The human retina and retinal pigment epithelium are abundant sources of vitronectin mRNA

Vitronectin (Vn), a multifunctional plasma protein synthesized primarily in the liver, is often present as a component of the extracellular plaques and deposits that accompany various age-related human diseases. Recently, we reported that Vn is also a prominent molecular constituent of drusen, the extracellular deposits associated with age-related macular degeneration (AMD) (1). The cellular source(s) of the Vn in drusen, as well as in these other plaques and deposits, remains uncertain. In this study, we used real-time quantitative RT-PCR to measure the relative levels of Vn mRNA in the cells and tissues that lie in close proximity to drusen. The results confirm that the human liver is an abundant source of Vn mRNA. Levels of Vn mRNA in kidney, lung, and fetal or adult brain are <3% of those in liver. Remarkably, mean Vn mRNA levels in the neural retina significantly exceed those in brain and represent close to 40% of the Vn mRNA value measured in human liver. Substantial levels of Vn mRNA are also present in the adjacent retinal pigment epithelium (RPE). These results identify the neural retina, for the first time, as an abundant source of Vn mRNA. They also suggest that both the neural retina and RPE are potent biosynthetic sources of Vn in humans, and potentially significant local contributors to the Vn that accumulates in drusen.

Molecular cloning and characterization of a surface antigen preferentially overexpressed on multiple myeloma cells

HM1.24 antigen has been identified as a surface molecule preferentially expressed on terminally differentiated B cells, and its overexpression is observed in multiple myeloma cells. The HM1.24 antigen is, therefore, expected as a most potent target molecule for antibody-based immunotherapy for multiple myeloma. Here, we have identified the cDNA for human HM1.24 antigen and also analyzed its gene structure including the promoter region. The HM1.24 antigen is a type II membrane glycoprotein, which has been reported as a bone marrow stromal cell surface antigen BST2, and may exist as a homodimer on myeloma cell surface. Although a reason for the overexpression in myeloma cells is not understood, very interestingly, the promoter region of the HM1.24 gene has a tandem repeat of three cis elements for a transcription factor, STAT3, which mediates interleukin-6 (IL-6) response gene expression. Since IL-6 is a differentiation factor for B cells, and known as a paracrine/autocrine growth factor for multiple myeloma cells, the expression of HM1.24 antigen may be regulated by the activation of STAT3. Importantly, a humanized anti-HM1.24 antibody effectively lysed the CHO transformants which expressed HM1.24 antigen as high as human multiple myeloma cells, but not the cells with lower antigen expression. This evaluation shows that ADCC heavily depends on the expression level of target antigens and, therefore, the immunotherapy targeting the HM1.24 antigen should have a promising potential in clinical use.

Rostrocaudal progression in the development of periodic spontaneous activity in fetal rat spinal motor circuits in vitro

Rostrocaudal progression in the development of periodic spontaneous activity in fetal rat spinal motor circuits in vitro. Developmental changes in the periodic spontaneous bursts in cervical and lumbar ventral roots (VRs) were investigated using isolated spinal cord preparations obtained from rat fetuses at embryonic days (E) 13.5-18. 5. Spontaneous bursts were observed in the cervical VR at E13.5-17.5, and in the lumbar VR at E14.5-17.5. Bursts occurrence in the cervical and lumbar VRs was correlated in a 1:1 fashion at E14.5-16. 5. The bursts in the cervical VR preceded those in the lumbar VR at E14.5, but the latter came to precede the former by E16.5. The interval between spontaneous bursts in the lumbar VR was greatly prolonged after spinal cord transection at the midthoracic level at E14.5, whereas that in the cervical VR became significantly longer at E14.5-16.5. These results suggest that the dominant neuronal circuit initiating the spontaneous bursts shifts from cervical to lumbar region during this period. Bath application of a glutamate receptor antagonist, kynurenate (4 mM), had little effect on the spontaneous bursts in either cervical or lumbar VRs at E14.5-15.5. At E16.5, kynurenate abolished the spontaneous bursts in the cervical VR. Concomitant application of kynurenate and strychnine (5 microM), a glycine receptor antagonist, abolished all spontaneous bursts, suggesting that the major transmitter mediating the spontaneous bursts changes from glycine to glutamate in the cervical region by E16.5, but not in the lumbar region during this period.

Multiwave coupling in a high-gain photorefractive polymer

The characteristics of a new high-gain photorefractive polymer composite with a PNP chromophore are investigated. Competition between beam fanning and two-wave coupling (TWC) is predicted and verified experimentally. The intensity dependence of TWC gain is studied. Higher diffraction order and forward phase conjugation in a TWC geometry are observed and explained.

The enabler cannula pump: a novel circulatory support system

BACKGROUND

The enabler circulatory support system is a catheter pump which expels blood from the left or right ventricular cavity and provides pulsatile flow in the ascending aorta or pulmonary artery. It is driven by a bedside installed pulsatile driving console. The device can easily be implanted by a minimal invasive approach, similar to the Hemopump.

PURPOSE

To demonstrate the hemodynamic performance of this new intracardiac support system.

METHODS

In a series of 9 sheep, hemodynamic evolutions were recorded in various conditions of myocardial contractility (the non-failing, the moderately failing and the severely failing heart). Heart failure was induced by injection of microspheres in the coronary arteries.

RESULTS

Introduction of the cannula through the aortic valve was feasible in all cases. Pump flow by the enabler was gradually increased to a maximum of 3.5 L/min. Diastolic (and mean) aortic blood pressure is significantly increased in the non-failing and moderately failing condition (counterpulsation mode). In heart failure, cardiac output is significantly increased by the pump (p < 0.0001). A drop in left atrial pressure (indicating unloading) is achieved in all conditions but reaches significant levels only during heart failure (p=0.0068).

CONCLUSIONS

This new circulatory support system contributes to stabilization of the circulation in the presence of cardiac unloading. In heart failure it actually supports the circulation by increasing cardiac output and perfusion pressure.

Reevaluation of discograms not classified into usual classifications

Discograms of images that were eccentrically dyed because of insufficient infiltration of contrast medium are difficult to classify into the usual past discogram patterns. In this study, these types of images were detected in 40 discs of 36 patients with lumbar disc disease. We classified these images into the following three types, and analyzed the dye mechanisms in each case by computed tomography discographic findings: (1) type A (image of the annulus fibrosus only). Nine discs in nine cases. A part of the marginal annulus fibrosus was dyed. (2) type B (image of the right or left half of the nucleus pulposus). Eighteen discs in 15 cases. Unilateral dyeing was considered nucleus pulposus existing in the central region of the disc. (3) type C (partial image of the superior or inferior half of the nucleus pulposus). Thirteen discs in 12 cases. Only the superior or inferior half showing a cotton-ball pattern was dyed.

The humanized anti-HM1.24 antibody effectively kills multiple myeloma cells by human effector cell-mediated cytotoxicity

A mouse monoclonal antibody, anti-HM1.24 (IgG2a/kappa), binds to a surface antigen preferentially overexpressed on multiple myeloma (MM) cells, and exhibits potent antitumor cell activity against MM cells by antibody-dependent cell-mediated cytotoxicity (ADCC). To develop an antibody-based immunotherapy against MM, a humanized anti-HM1.24 antibody, in which all FRs correspond to naturally processed human FRs, has been successfully constructed with the aid of both the hybrid variable region and two-step design methods. This humanized anti-HM1.24 antibody (IgG1/kappa) is able to effectively induce ADCC against human myeloma KPMM2 and ARH77 cells in the presence of human PBMCs as effectively as a chimeric anti-HM1.24 antibody. The humanized anti-HM1.24 antibody, therefore, could be expected as a potent immunotherapeutic agent for MM patients.

A novel A-isoform-like inositol 1,4,5-trisphosphate 3-kinase from chicken erythrocytes exhibits alternative splicing and conservation of intron positions between vertebrates and invertebrates

Based on the partial peptide sequence of inositol 1,4, 5-trisphosphate 3-kinase purified with 135 000-fold enrichment from chicken erythrocytes, cDNA-fragments were cloned by RT-PCR using degenerate oligonucleotides. Subsequent hybridization screening of an embryonic chicken cDNA library and 5'-RACE yielded a cDNA-contig of 2418 bp, encoding a 452 amino acid protein. The amino acid sequence shows the highest degree of homology with A-isoforms of inositol 1,4,5-trisphosphate 3-kinase (65% identities), whereas homology towards B and C isoforms was lower (57% and 52% amino acid identities respectively). These findings reveal a new tissue-specific pattern of A-isoform expression, a form which so far has only been found in brain and testes. Two overlapping lambda-genomic clones for chicken inositol 1,4,5-trisphosphate 3-kinase, isolated by hybridization screening, covered 18 499 bp of genomic sequence. This contig included four exons: three of them were present in all cDNA clones, whereas one was only represented in a single cDNA clone. In addition, the sequence of the latter differed from the other cDNAs by an in-frame deletion of 72 bp within the coding region for the catalytic domain of the enzyme. This divergent cDNA suggests the existence of alternative splice products, at least in embryonic tissue.A comparison of the position of introns, with the respective introns known from the corresponding gene from Caenorhabditis elegans, revealed a high degree of conservation of intron positions between vertebrates and invertebrates. Functional data for the enzyme suggests that the conserved exons represent defined functional protein modules.

An angiographically occult arteriovenous malformation in the medial parietal lobe presenting as seizures of medial temporal lobe origin

We present an unusual case of a patient who was diagnosed with temporal lobe epilepsy and whose seizures were reduced markedly after excision of an angiographically occult arteriovenous malformation (AVM) located in the left medial parietal lobe. A 38-year-old man had complex partial seizures characterized by motionless staring with oroalimentary and behavioral automatisms since the age of 15 years. Magnetic resonance imaging (MRI) demonstrated a small lesion extending from the left posterior cingulate gyrus to the precuneus. There was no MRI evidence of mesial temporal sclerosis. Intracranial EEG recordings showed ictal onset from the left medial parietal lobe propagating to the medial temporal lobes. Clinical signs appeared when these discharges reached the temporal lobes. After excision of the lesion (which was histologically confirmed as an AVM), together with the marginal cortex, seizures were reduced significantly. Careful diagnostic evaluation of lesions such as the this one may reveal an epileptogenic lesion (zone) far from the region where scalp ictal discharges seem to arise. In our case, we hypothesize that false localization was due to propagation of ictal discharges from the parietal focus through the limbic system.