Implantation on the suture material and efficacy of povidone-iodine solution

Suture implantation of viable exfoliated tumour cells may be responsible for local recurrence of colorectal cancer. Using a colon cancer cell line, we obtained a suture implantation without intraperitoneal metastasis in about 80% of the control animals, when sacrificed on the 2nd postoperative week. The cytotoxic efficacy of povidone-iodine (PVP-I) was tested in vivo by a rat model with viable intracaecal tumour cells, and in vitro by trypan blue exclusion and the MTT assay. In vivo PVP-I at 5% significantly reduced the incidence of tumour growth, while the product at 2.5% had a significant effect in only the monofilament polypropylene group. In an in vitro toxicity study, PVP-I higher than 0.16% was effective at killing almost all tumour cells. PVP-I had effective cytotoxicity in vivo and in vitro, being less cytotoxic in vivo than in vitro.

Failure of germinal center formation and impairment of response to endotoxin in tumor necrosis factor alpha-deficient mice

To study the pathophysiologic roles of TNF alpha, we produced TNF alpha gene-disrupted mice by gene targeting. TNF alpha-deficient mice develop normally without any alteration in the lymphocyte populations. However, in these mice, the germinal center formation in the peripheral lymphoid organs failed in response to the T cell-dependent antigens. TNF alpha-deficient mice are resistant to lethal doses of endotoxin and D-galactosamine without hepatocyte apoptosis, yet demonstrate thymus apoptosis. Our results indicated an important role for TNF alpha in germinal center formation and in the sepsis-induced hepatocyte apoptosis that precedes liver failure.

Coupled vs. uncoupled pericardial constraint: effects on cardiac chamber interactions

The effects of pericardial constraint on cardiac chamber interactions were evaluated by mathematical model analyses based on a novel concept of coupled vs. uncoupled pericardial constraint. We hypothesized that the nature of pericardial constraint can be classified as a "coupled" constraint exerted by uniform liquid pressure or an "uncoupled" constraint exerted by regional surface pressure. The numerical solution of the model of atrioventricular interaction produced the characteristic waveforms in venous flows and right atrial/ventricular pressures in classical pericardial diseases. Coupled constraint accounted for the patterns in cardiac tamponade; uncoupled constraint accounted for those in constrictive pericarditis. Analytic solution of the model of ventricular interdependence demonstrated that coupled constraint (tamponade) produced greater gains in ventricular interdependence, increasing the occurrence of pulsus paradoxus, whereas uncoupled constraint (constriction) produced a greater effective right ventricular elastance, increasing the likelihood of Kussmaul's sign. Thus the concept of coupled vs. uncoupled constraint may offer a coherent framework to understand the characteristic steady-state and respiratory-induced hemodynamic events in multiple forms of pericardial diseases.

CedA is a novel Escherichia coli protein that activates the cell division inhibited by chromosomal DNA over-replication

We isolated and characterized a new gene related to the control of cell division regulation in Escherichia coli. At 30 degrees C, the dnaAcos mutant causes over-replication of the chromosome, and colony formation is inhibited. We found that, at this temperature, the dnaAcos cells form filaments; therefore, septum formation is inhibited. This inhibition was independent of SfiA, an inhibitor of the septum-forming protein, FtsZ. To identify factors involved in this pathway of inhibition, we isolated seven multicopy suppressors for the cold-sensitive phenotype of the dnaAcos mutant. One of these proved to be a previously unknown gene, which we named cedA. This gene encoded a 12 kDa protein and resided at 38.9min on the E. coli genome map. A multicopy supply of the cedA gene to the dnaAcos cells did not repress over-replication of the chromosome but did stimulate cell division of the host, the result being growth of cells with an abnormally elevated chromosomal copy number. Therefore, the expression level of the cedA gene seems to be important for inhibiting cell division of the dnaAcos mutant at 30 degrees C. We propose that over-replication of the chromosome activates a pathway for inhibiting cell division and that the cedA gene modulates this division control. In the dnaA+ background, cedA also seems to affect cell division.

The effects of long-term treatment on left ventricular hypertrophy in patients with essential hypertension: relation to changes in neurohumoral factors

This study compared the effects of 1 year of monotherapy with a calcium-channel antagonist (nilvadipine; NIL), an angiotensin-converting enzyme (ACE) inhibitor (temocapril; TEM), or a new vasodilator (cadralazine; CAD) on left ventricular (LV) hypertrophy in essential hypertension. Furthermore, to elucidate the mechanism responsible for regression of LV hypertrophy after treatment, LV mass index (LVMI) by echocardiography, plasma renin activity (PRA), aldosterone (PAC), norepinephrine, and atrial natriuretic peptide (ANP) concentration were measured before and after treatment. Thirty-six patients were randomly assigned to the NIL, TEM, or CAD groups. Blood pressure (BP) before treatment was 174 +/- 10/104 +/- 7, 173 +/- 18/103 +/- 8, and 171 +/- 16/103 +/- 7 mm Hg (mean +/- SD) in NIL, TEM, and CAD groups, respectively. BP was lower after treatment with each of the three test drugs than after the placebo period, and there were no differences in BP reduction among three groups. LVMI, in NIL and TEM, was reduced from 129 +/- 48 to 115 +/- 39 g/m2 and from 117 +/- 39 to 88 +/- 20 g/m2 (p < 0.05 and p < 0.01, respectively), whereas, in the CAD group, it was increased (110 +/- 30 to 138 +/- 27 g/m2; p < 0.01). In the CAD group, PAC decreased and ANP increased significantly. The change in LVMI correlated with that in BP for TEM and with that in ANP in all patients. These data indicated that LV volume overload as well as LV pressure overload may contribute to LV hypertrophy and that monotherapy with CAD is not desirable from the point of view of LV mass reduction in essential hypertension.

Expression of platelet-derived growth factor in lupus nephritis in MRL/MpJ-1pr/1pr mice

Platelet-derived growth factor (PDGF) plays an important role in the pathogenesis of mesangial proliferative glomerulonephritis. We examined PDGF expression and glomerular changes in lupus nephritis-prone MRL/MpJ-1pr/1pr (MRL/1) mice. The total number of nuclei per glomerular section and blood urea nitrogen (BUN) level were significantly increased in MRL/1 mice aged 20 weeks compared to those aged 8 weeks. A positive correlation existed between numbers of PDGF beta-chain-positive cells and glomerular cells in MRL/1 mice (r = 0.77, p < 0.01). The BUN level did not differ among MRL/MP-+2 (MRL/n) mice of different ages, but the glomerular cell number increased modestly with age. At the age of 20 weeks, the incidence of crescent formation per kidney tissue ranged from 9 to 32% (mean 19%) in MRL/1 mice but was 0 in MRL/n mice. PDGF beta-chain protein was expressed in the mesangium and crescents in 20-week-old MRL/1 mice but was expressed rarely in the glomeruli of MRL/n mice. These results suggest that the PDGF beta-chain plays an important role in glomerular cell proliferation and crescent formation in murine lupus nephritis.

Phosphoinositide 3-kinase is required for insulin-induced but not for growth hormone- or hyperosmolarity-induced glucose uptake in 3T3-L1 adipocytes

The(1) regulatory mechanism of glucose uptake in 3T3-L1 adipocytes was investigated with the use of recombinant adenovirus vectors encoding various dominant negative proteins. Infection with a virus encoding a mutant regulatory subunit of phosphoinositide (PI) 3-kinase that does not bind the 110-kDa catalytic subunit (delta p85) inhibited the insulin-induced increase in PI 3-kinase activity co-precipitated by antibodies to phosphotyrosine and glucose uptake in a virus dose-dependent manner. Overexpression of a dominant negative RAS mutant in which Asp57 is replaced with tyrosine (RAS57Y) or of a dominant negative SOS mutant that lacks guanine nucleotide exchange activity (delta SOS) abolished the insulin-induced increase in mitogen-activated protein kinase activity, but had no effect on PI 3-kinase activity or glucose uptake. Although GH and hyperosmolarity attributable to 300 mM sorbitol each promoted glucose uptake and translocation of glucose transporter (GLUT)4 to an extent comparable to that of insulin, these stimuli triggered little or no association of PI 3-kinase activity with tyrosine-phosphorylated proteins. Overexpression of delta p85 or treatment of cells with wortmannin, an inhibitor of PI 3-kinase activity, had no effect on glucose uptake or translocation of GLUT4 stimulated by GH or hyperosmolarity. Moreover, overexpression of delta SOS or RAC17N also did not affect the increase in glucose uptake induced by these stimuli. A serine/threonine kinase Akt, a constitutively active mutant of which was previously shown to stimulate glucose uptake, is activated by insulin, GH, and hyperosmolarity to approximately 4-fold, approximately 2.1-fold, and approximately 2.3-fold over basal level, respectively. These results suggest that insulin-induced but neither GH- or hyperosmolarity-induced glucose uptake is PI 3-kinase-dependent, and neither RAS nor RAC is required for glucose uptake induced by these stimuli in 3T3-L1 adipocytes.

Molecular cloning of bovine CD14 gene

Genomic DNA encoding bovine CD14 was isolated from a bovine (Holstein) genomic library. Utilizing PCR fragment of mouse CD14 gene as a probe, we screened 9 x 10(5) plaques and obtained 3 clones containing the bovine CD14 gene. DNA sequencing showed that bovine CD14 gene encodes 373 amino acids, and the coding sequence was separated by a 90 nt intron. The identity of the deduced amino acid sequence of bovine CD14 was 61-73% to those of mouse, rabbit and human. Northern blot analysis revealed that CD14 mRNA (1.5 kb) was expressed in the lung. Expression of CD14 mRNA was stimulated about 2-fold in bovine peripheral blood macrophage activated with LPS in vitro.

Intraalveolar expression of tumor necrosis factor-alpha gene during conventional and high-frequency ventilation

The effects of conventional mechanical ventilation (CMV) and high-frequency oscillatory ventilation (HFO) on intraalveolar expression of the tumor necrosis factor-alpha (TNF-alpha) gene were studied in surfactant-depleted rabbits. After lung lavage with saline, 13 rabbits were administered either CMV (n = 6) or HFO (n = 7) for 1 h at an FiO2 of 1.0 and a mean airway pressure of 13 cm H2O. Lung lavage was then repeated. The rabbits' RNA was extracted from the lavage cells, and mRNA for TNF-alpha was quantitated by reverse-transcription polymerase chain reaction using glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as an internal standard. At 1 h of ventilation, PaO2 was slightly lower with CMV than HFO, while lavage cell counts and cytology were similar between the two groups. The ratio of TNF-alpha mRNA to GAPDH mRNA increased with CMV (control, 0.48 +/- 0.04 [SE] versus 1 h, 1.02 +/- 0.14, p < 0.01) but did not change with HFO (0.55 +/- 0.07 versus 0.73 +/- 0.09). In a separate series of experiments, ten surfactant-depleted rabbits continued to be ventilated for 4 h either by CMV (n = 5) or HFO (n = 5). Conventional mechanical ventilation resulted in a progressive hypoxemia, decreased lung compliance, increased number of neutrophils in lung lavage fluid, and substantial morphological changes including hyaline membrane formation and neutrophil accumulation, whereas HFO was associated with minimal changes in such physiological and pathological abnormalities. These results suggest that activation of alveolar macrophages and production of proinflammatory cytokines may play a pivotal role in the early stage of ventilator-induced lung injury, and that ventilator mode (CMV or HFO) substantially modulates macrophage activation and hence the degree of lung injury.

A catalytic amino acid and primary structure of active site in Aspergillus niger alpha-glucosidase

The catalytic amino acid residue of Aspergillus niger alpha-glucosidase (ANGase) was identified by modification with conduritol B epoxide (CBE), a mechanism-based irreversible inactivator. The inactivation by CBE followed pseudo-first order kinetics. The interaction of CBE and ANGase conformed to a model with a reversible enzyme-inhibitor complex formed before covalent inactivation. A competitive inhibitor, Tris, decreased the inactivation rate. The incorporation of one mole of CBE per mole of ANGase was completely abolished the enzyme activity. A dissociated carboxyl group (-COO-) in the active site was suggested to attack the C-1 of CBE. ANGase was composed of two subunits (P1 and P2), of which P2 was modified by CBE. The labelled residue was included in a peptide (LY3) that was obtained from Lys-C protease digestion of CBE-bound P2. The sequence analysis of CBE-labelled LY3 showed that an Asp was the modified residue, that is, one of the catalytic amino acid residues of ANGase. The primary structure of LY3 was determined by analyzing the sequence of peptide fragments prepared by several proteases.

Genetic evidence for involvement of type 1, type 2 and type 3 inositol 1,4,5-trisphosphate receptors in signal transduction through the B-cell antigen receptor

Stimulation of B-cell antigen receptor (BCR) induces a rapid increase in cytoplasmic free calcium due to its release from intracellular stores and influx from the extracellular environment. Inositol 1,4,5-trisphosphate receptors (IP3Rs) are ligand-gated channels that release intracellular calcium stores in response to the second messenger, inositol 1,4,5-trisphosphate. Most hematopoietic cells, including B cells, express at least two of the three different types of IP3R. We demonstrate here that B cells in which a single type of IP3R has been deleted still mobilize calcium in response to BCR stimulation, whereas this calcium mobilization is abrogated in B cells lacking all three types of IP3R. Calcium mobilization by a transfected G protein-coupled receptor (muscarinic M1 receptor) was also abolished in only triple-deficient cells. Capacitative Ca2+ entry, stimulated by thapsigargin, remains unaffected by loss of all three types of IP3R. These data establish that IP3Rs are essential and functionally redundant mediators for both BCR- and muscarinic receptor-induced calcium mobilization, but not for thapsigargin-induced Ca2+ influx. We further show that the BCR-induced apoptosis is significantly inhibited by loss of all three types of IP3R, suggesting an important role for Ca2+ in the process of apoptosis.

Simultaneous measurement of serum 5-S-cysteinyldopa, circulating intercellular adhesion molecule-1 and soluble interleukin-2 receptor levels in Japanese patients with malignant melanoma

Serum 5-S-cysteinyl dopa (5-S-CD), circulating intercellular adhesion molecule-1 (cICAM-1) and soluble interleukin-2 receptor (sIL-2R) have each been reported as useful markers for melanoma progression. To assess the clinical relevance of these three markers, we simultaneously assayed their serum levels in 30 Japanese melanoma patients. Pre-surgical serum levels of 5-S-CD, cICAM-1 and sIL-2R were elevated in six, 13 and five patients respectively. These abnormal values returned to normal after curative surgery in most of the patients, suggesting a direct relationship to the presence of the primary tumour. Pre-surgical values of these three markers, either individually or in combination, did not predict the development of subsequent metastases. The sequential measurements of the three markers in eight patients who had relapse after surgery showed that serum 5-S-CD is the most useful marker for disease progression, although it is dependent on the melanin-producing ability of individual recurrent tumours. sIL-2R seemed to reflect in vivo activation of the host immune system and was a good indicator for predicting occult metastasis in selected cases. Circulating ICAM-1 levels were less relevant to the clinical disease course in our cases, although they tended to increase strikingly after liver metastasis. Our results in this limited number of cases show that the significance of the three markers varied with the individual and suggest that the simultaneous measurement of these markers may facilitate the early detection of metastases and proper therapeutic intervention.

p53 mutation spectrum in Japanese Bowen's disease suggests a role for mutagens other than ultraviolet light

The Japanese have a much lower incidence of nonmelanoma skin cancers (NMSCs) than Caucasians, presumably due in part to their skin type conferring relative protection from ultraviolet light radiation (UVR). To examine the contribution of environmental or endogenous mutagens other than UVR, which are expected to be relatively more important to the overall burden of NMSCs in the Japanese, we directly sequenced exons 5-8 of the p53 tumour suppressor gene in 29 Japanese patients with Bowen's disease, an in situ squamous-cell carcinoma of the skin. We found 9 mutations, including two CC:GG to TT:AA tandem transitions (presumably related to UVR), 3 transversions and 4 frameshift mutations. The mutational spectrum seen in our study contrasts with that we previously found in Bowen's disease from a Caucasian population, in keeping with a different aetiology for Bowen's disease in the respective populations. The unexpectedly high prevalence of frameshift mutations suggests that environmental mutagens other than UVR that preferentially induce deletion or insertion mutations may play an important role in the tumorigenesis of Japanese Bowen's disease, and warrants further investigation.

Evaluation of an extracorporeal membrane oxygenation system using a nonporous membrane oxygenator and a new method for heparin coating

A new heparin binding method was applied to a miniature extracorporeal membrane oxygenation (ECMO) system with a nonporous membrane oxygenator (the priming volume, 45 mL; the membrane surface area, 0.4 m2; maximal flow rate, 2 L/min) that is resistant to plasma leakage. The authors evaluated the stability of the immobilized heparin in vitro and the feasibility of this system in animals. Samples of hollow fibers and tubing were rinsed at 40 degrees C for 4 days in normal saline, Ringer's lactate, and 1 mol/L NaCl solution. Heparin activities on hollow fibers after rinsing were 99 +/- 2.3% (mean +/- SD), 96 +/- 3.9%, and 93 +/- 2.0% of the control in each solution, while those of the tubing were 87 +/- 4.1%, 86 +/- 3.1%, and 76 +/- 8.6%, respectively. Veno-arterial ECMO using this heparin-coated system was performed on five beagles (8 to 12 kg) for 10 hours. Neither major thrombus formation nor plasma leakage was detected during the procedure in spite of a low flow rate (300 mL/min) and a reduced activated clotting time (mean, 128 seconds). Platelets decreased to 52% of the control (P < .01) at 1 hour, but no progressive decrease was seen thereafter. Antithrombin-III decreased (P < .01) and thrombin/antithrombin III complex increased (P < .05 at 4 hours and P < .01 at 6, 8, and 10 hours) during bypass, but the changes of fibrinogen and fibrinopeptide A were not significant. Fibrinogen/fibrin degeneration products, fibrinopeptide B beta 15-42, and plasma-free hemoglobin levels did not rise significantly. O2 transfer of the oxygenators at a flow rate of 300 mL/min were 12.3 +/- 0.4 mL/min at 30 minutes, 14.3 +/- 1.2 mL/min at 5 hours, and 14.7 +/- 1.7 mL/min at 10 hours (no statistical difference). Histological examination of the brains and the kidneys showed no evidence of thromboembolic sequela in any of the animals. These results suggest that this new system is a promising device for long-term ECMO in which the amount of systemic heparinization can be reduced with the minimal possibility of plasma leakage.

Excitation of hypoglossal motoneurons responsible for tongue protrusions is associated with palatally induced jaw-closing reflex

The excitation of hypoglossal motoneurons innervating the genioglossus and geniohyoid muscles during transient jaw closing, the so-called jaw-closing reflex, was studied in cats. The application of diffuse pressure stimulation to the posterior palatal surface produced the jaw-closing reflex, and it was found that mechanosensory inputs from the posterior palatal mucosa sent excitatory synaptic inputs to both genioglossus and geniohyoid motoneurons. We demonstrated that, during the palatally induced jaw-closing reflex, the tongue extended at jaw closure and was still extended forward in the initial part of the opening phase. In five of 27 genioglossus motoneurons and nine of 23 geniohyoid motoneurons, the onset of burst was elicited before the onset of jaw closure. The remaining cells produced the onset of burst in the closing phase and in the initial part of the occlusal phase. However, the onset of excitatory postsynaptic potentials was 75-180 ms (n=20), earlier than that of jaw closure. During the jaw-closing reflex, the genioglossus and geniohyoid motoneurons were excited during the same phase of jaw movements and there was no difference in the onset of firing between the genioglossus and geniohyoid motoneurons. It is concluded that the excitation of the genioglossus and geniohyoid motoneurons may be associated with tongue protrusions during the palatally induced jaw-closing reflex.

[Repeated low-flow sevoflurane anesthesia: effects on hepatic and renal function in beagles]

We studied the effects of repeated low-flow sevoflurane anesthesia for 6 hours. Five beagle dogs received 1.3 MAC (3%) sevoflurane anesthesia. Anesthesia of 6 hours was repeated on at the 7th day after the first anesthesia. Compound A gas samples were collected from the inspiratory limb during anesthesia. Concentrations of serum and renal fluoride, hepatic and renal function parameters were measured during and up to 7 days after the first and second anesthesia. The peak concentration of compound A was 23.7 +/- 3.6 ppm at 2 hours and the same level remained during the anesthesia. Plasma fluoride level exceeded 50 mmol.l-1 during anesthesia and rapidly decreased to the preanesthesia level thereafter. Serum GOT increased slightly only on the first postanesthesia day. No significant changes in other blood chemistry studies were observed. The excretion of renal tubular enzymes did not increase during and after anesthesia. Repeated low flow sevoflurane anesthesia in beagles did not affect hepatic and renal function significantly.

Tape stripping induces marked epidermal proliferation and altered TGF-alpha expression in non-lesional psoriatic skin

Psoriasis is a chronic inflammatory disorder characterized by epidermal hyperproliferation. Although recent evidence suggests that T cell activation is a primary trigger for psoriasis lesions, there may be alterations in the keratinocyte growth regulatory pathways which induce epidermal hyperproliferation in psoriatic patients. To test this hypothesis, we investigated the proliferative activity of epidermal keratinocytes 48 h after tape stripping, one of the standard mechanical ways to stimulate the epidermis, in 20 psoriasis patients and in 18 controls. Epidermal cell kinetics were assessed with DNA flow cytometry, the mitotic index, bromodeoxyuridine incorporation, Ki-67 antigen expression and DNA polymerase alpha expression. The expression of TGF-alpha and EGF receptors, critical mediators of keratinocyte proliferation, were also investigated immunohistochemically. The results of multiparameter assays showed that the baseline proliferative activity in uninvolved skin was the same in psoriasis patients and normal controls. After tape stripping, although both psoriasis patients and the normal controls showed significant increases in epidermal cell proliferation, the values of all the parameters investigated were significantly greater in the psoriasis patients than in the normal controls. EGF receptors were overexpressed in basal and suprabasal keratinocytes after tape stripping in both the psoriasis patients and the normal controls. In contrast, overexpression of TGF-alpha was only observed in the patients with psoriasis, which may explain their increased proliferative response to trauma.

Low frequency of allelic loss in skin tumours from immunosuppressed individuals

Organ transplant recipients receiving immunosuppression show a dramatically increased risk of non-melanoma skin cancer. The cause of this increase is not known. We report that the rate of loss of heterozygosity (at all the loci we examined) was significantly lower in tumours from immunosuppressed individuals than in tumours from immunocompetent subjects [20 out of 148 (14%) vs 157 out of 428 (37%); P< 0.0001]. These results suggest that tumours in immunosuppressed individuals have a different molecular pathogenesis.

Tumour cells of extramammary Paget's disease do not show either p53 mutation or allelic loss at several selected loci implicated in other cancers

Extramammary Paget's disease is a particular form of skin cancer of unknown histogenesis. To look for the genetic defects underlying the pathogenesis of this tumour, we have examined loss of heterozygosity (LOH), p53 and human papillomavirus (HPV) status, and the expression of c-erbB-2 and bcl-2 proteins in 14 cases. Unexpectedly, no LOH was detected at several loci commonly lost in other human cancers (namely 3p, 9p, 9q, 13q, 16q, 17p, and 17q) in 12 tumours examined. Altered p53 protein expression was entirely or mostly negative in all 14 cases. Direct sequencing of exons 5-8 of the p53 gene in eight cases revealed no mutation. Polymerase chain reaction amplification of the L1 gene of human papillomavirus (HPV) did not detect the virus that could inactivate p53 and retinoblastoma tumour-suppressor gene products. As expected, c-erbB-2 proto-oncogene protein was overexpressed in six cases. The expression of bcl-2 was negative in all cases. The results presented in this study suggest that molecular events underlying extramammary Paget's disease differ from those of other common epithelial malignancies and that tumour-suppressor genes located in chromosome regions not examined in this study may be important.

Disruption of the hslU gene, which encodes an ATPase subunit of the eukaryotic 26S proteasome homolog in Escherichia coli, suppresses the temperature-sensitive dnaA46 mutation

The Escherichia coli hslVU genes encode subunits of an ATP-dependent protease, a homolog of the eukaryotic 26S proteasome. We found that the hslU gene is required for the temperature (40 degrees C)-sensitive phenotype of the dnaA46 mutant, while other soluble ATP-dependent proteases, La (Lon) and Ti (Clp), were unrelated to this dnaA46 phenotype. Disruption of the hslU gene inhibited cell growth at high temperatures. These observations suggest a specific in vivo role for HslVU protease in denatured proteins. As the absence of HslU produces minicells in M9 medium, the protease may be involved in the cell cycle regulation.