Nitric oxide inhibits the synthesis of type-II collagen without altering Col2A1 mRNA abundance: prolyl hydroxylase as a possible target

The addition of human recombinant interleukin-1beta (IL-1beta) to cultures of lapine articular chondrocytes provoked the synthesis of large amounts of NO and reduced the production of type-II collagen. NG-Monomethyl-l-arginine (L-NMA), an inhibitor of NO synthase, strongly suppressed the production of NO and partially relieved the inhibition of collagen synthesis in response to IL-1beta. The NO donor S-nitrosoacetylpenicillamine (SNAP), on the other hand, inhibited collagen production. IL-1 lowered the abundance of Col2A1 mRNA in an NO-independent manner. Collectively, these data indicate that IL-1 suppresses collagen synthesis at two levels: a pretranslational level which is NO-independent, and a translational or post-translational level which is NO-mediated. These effects are presumably specific as L-NMA and SNAP had no effect on total protein synthesis or on the distribution of newly synthesized proteins between the cellular and extracellular compartments. Prolyl hydroxylase is an important enzyme in the post-translational processing of collagen, and its regulation and cofactor requirements suggest possible sensitivity to NO. Extracts of cells treated with IL-1 or SNAP had lower prolyl hydroxylase activity, and L-NMA was partially able to reverse the effects of IL-1. These data suggest that prolyl hydroxylase might indeed be a target for NO. Because underhydroxylated collagen monomers fail to anneal into stable triple helices, they are degraded intracellularly. Inhibition of prolyl hydroxylase by NO might thus account for the suppressive effect of this radical on collagen synthesis.

Purification and characterization of myofibril-bound serine proteinase from carp Cyprinus carpio ordinary muscle

1. A novel myofibril-bound serine proteinase (MBP) has been purified from ordinary muscle of the carp Cyprinus carpio. 2. It was solubilized from the myofibril fraction with acid treatment (under the conditions of 0.6 M KCl, pH 4.0), then purified by column chromatographic steps on Ultrogel AcA 54, and Arginine-Sepharose 4B. 3. The purified enzyme revealed a single protein band on SDS-PAGE, and its molecular mass was estimated to be 30 kDa by SDS-PAGE and gel filtration. 4. The optimum pH and temperature of the enzyme were 8.0 and 55 degrees C, respectively, when Boc-Phe-Ser-Arg-MCA and casein were used as substrates. 5. The enzyme hydrolyzed Boc-Gln-Arg-Arg-MCA most rapidly, and also hydrolyzed the substrates for trypsin-type proteinase, but not for chymotrypsin. The enzyme was inhibited by serine proteinase inhibitors such as DFP, STI and leupeptin. These results suggested that the enzyme was a trypsin-type serine proteinase. 6. Boc-Phe-Ser-Arg-MCA hydrolyzing activity of the purified enzyme was reduced by addition of NaCl, but the caseinolytic activity and Boc-Phe-Ser-Arg-MCA hydrolyzing activity of the partially purified enzyme were activated by NaCl.

Effect of growth factors on matrix synthesis by ligament fibroblasts

Although it has been reported that several growth factors modulate soft-tissue healing, the specific effects of growth factors on protein synthesis during ligament healing have not been widely investigated. In this study, we examined the effects of basic and acidic fibroblast growth factors, transforming growth factor beta 1, and epidermal growth factor on collagen and noncollagenous protein synthesis by cultured fibroblasts from medial collateral ligament and anterior cruciate ligament in vitro. Uptake of tritiated proline was used to measure synthesis of collagen and noncollagenous protein, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze the type of collagens synthesized. Our data showed that transforming growth factor beta 1 increased both collagen and noncollagenous protein synthesis by medial collateral and anterior cruciate ligament fibroblasts on a dose-dependent basis. Collagen synthesis by cultured fibroblasts from the medial collateral and anterior cruciate ligaments was increased by treatment with transforming growth factor beta 1 by as much as approximately 1.5 times that of untreated controls. Although the response to transforming growth factor beta 1 by anterior cruciate ligament fibroblasts was equal to that by medial collateral ligament fibroblasts, the amounts of matrix proteins synthesized by anterior cruciate ligament fibroblasts were approximately half of that by medial collateral ligament fibroblasts. The increase was mostly in type-I collagen. Treatment of anterior cruciate ligament fibroblasts with epidermal growth factor increased collagen synthesis by approximately 25% but had little effect on medial collateral ligament fibroblasts. Neither basic nor acidic fibroblast growth factor increased either collagen or noncollagenous protein synthesis. These findings suggest that topical application of transforming growth factor beta 1, alone or in combination with epidermal growth factor, may have the potential to strengthen the ligament by increasing matrix synthesis during its remodeling and healing processes.

Detection of right ventricular ischaemia during coronary surgery by means of a right precordial lead

This study was designed to determine the intra-operative incidence of right-sided ventricular ischaemia and any association with left ventricular ischaemia. In 60 patients, undergoing coronary artery bypass grafting surgery, a right-sided precordial lead V5R was used. ST segment deviation of more than 1 mm in V5R was considered significant for myocardial ischaemia. Right ventricular ischaemia occurred in 14 patients (23.3%) but was not associated with left ventricular inferior wall ischaemia. In 4 patients (6.6%) presenting with right ventricular ischaemia, ischaemia of the left inferior wall also developed but in all cases was transient and disappeared by the end of surgery. No myocardial infarction was detected in the post-operative period. The present study showed that the use of a right-sided lead may improve intra-operative electrocardiographic monitoring, by revealing ischaemia in those patients in whom ECG abnormalities were not detected by conventional leads. The transient right ventricular ischaemia recorded in this study was probably related to a reduced hypothermic protection of the right ventricle during aortic cross clamping.

[Stroke in the young: a diagnostic protocol]

This study attempts to propose guidelines for diagnostic procedures in young adults with focal cerebral ischemia. Our data indicate that the most common etiologies are atherothrombosis (primarily in 40-47-year-old subjects), and cardioembolism (more prevalent in subjects under 30 years old). Autoimmune conditions were observed in 12.6%, and arterial dissections in 11% of our patients. Despite extensive diagnostic studies, we were unable to determine the etiology of the cerebral ischemic event in 10% of our patients.

SCG10, a neuron-specific growth-associated protein in Alzheimer's disease

Neuronal growth-associated proteins (nGAPs) are markers of neuronal process outgrowth and are associated with both degenerative and sprouting responses in Alzheimer's disease (AD) brain. To study possible involvement of SCG10, an nGAP, in AD, we cloned human SCG10 cDNA and analyzed SCG-10 at mRNA and protein levels in control and AD brains. The deduced amino acid sequence of human SCG10 was 69% identical to stathmin, another nGAP. By in situ hybridization, both SCG10 and stathmin mRNAs were detected in selected neuronal populations in aged human brains. Quantitative analysis by RNase protection revealed that levels of neither SCG10 nor stathmin mRNAs were significantly altered in AD. Using an SCG10-specific antibody, Western blot analysis did not reveal any quantitative changes of SCG10 in AD. However, when the concentration of SCG10 protein was plotted against the number of tangles, a positive correlation was found. SCG10 levels did not correlate with plaque numbers. Furthermore, immunohistochemical study revealed that neuronal SCG10 protein accumulated in the cell bodies in AD-affected regions. Thus, SCG10 compartmentalization and metabolism may be altered in AD possibly due to mechanisms related to tangle formation in this disease.

Reduced expression of the molecular markers of dopaminergic neuronal atrophy in the aging rat brain

Expression of mRNAs encoding the dopamine transporter (DAT) and tyrosine hydroxylase (TH) in dopaminergic neurons of the substantia nigra (SN) was examined in young and aged Fischer 344 rats by in situ hybridization. Quantitative analysis revealed a statistically significant decline in both DAT and TH mRNA expression in 24-month-old rats in comparison to 6-month-old rats. In addition, it was noted that DAT mRNA expression tended to decrease by 18 months, while TH mRNA reduction did not occur until 24 months. The age-related loss of DAT and TH mRNA expressions was accompanied by diminished expression of mRNA for a neuronal growth-associated protein GAP-43, but not for SCG10 or alpha 1-tubulin. The loss of GAP-43 mRNA became evident when both DAT and TH gene expression declined with advanced age. Our findings indicate that DAT may be a marker of atrophy in dopamine neurons during normal aging.

Preparation and characterization of monoclonal antibodies against aflatoxin B1

Five hybridoma cell lines producing monoclonal antibodies (MAb) against Aflatoxin B1 (AFB1) were established after fusion of mouse myeloma cells (SP-2/O-Ag-14) with spleen cells isolated from male BALB/c mice immunized with AFB1-BSA conjugate. Among these, one MAb, designated AFB1-2H8, was of the subtype IgG3 and the acidic fluid of which gave high dilution titers (1:5 x 10(5). The sensitivity of a competitive inhibition enzyme immunoassay (CIEIA) using AFB1-2H8 for AFB1 demonstrated that the linear range was 0.5-50 ng/ml and the minimum detectable concentration of AFB1 was 0.01 ng/ml. The specificity of the MAb was determined and showed no significant crossreaction with any of the metabolites tested. So th-- MAb and the CIEIA described may be useful in the detection of AFB1 in food and feed.

Free-space regular optical interconnections: a mathematical analysis

The matrix descriptions for three types of free-space regular optical interconnection networks, the perfect shuffle, the banyan, and the crossover, are given. Some new properties of the perfect shuffle are presented in matrix equations, and the equivalence of the three types of interconnection networks is simply shown.

Cloning, expression, and characterization of Cryptococcus neoformans dihydrofolate reductase

The Cryptococcus neoformans dihydrofolate reductase (DHFR) gene has been isolated from cDNA and genomic DNA libraries. The 690-base pair coding sequence codes for a 25,152-Da protein, which is the largest monofunctional DHFR yet reported. The gene contains two introns, and several putative regulatory sequences have been identified. The coding sequence was placed in a pUC-based expression vector, which expresses C. neoformans DHFR in Escherichia coli at a level of about 5% of the total soluble extract. The expressed DHFR was purified to homogeneity by methotrexate-Sepharose affinity chromatography, followed by anion exchange chromatography on Q-Sepharose. On SDS-polyacrylamide gel electrophoresis, the purified enzyme migrates as a single protein with apparent mass of 28 kDa. The molecular weight, as determined by electrospray mass spectral analysis, and the amino-terminal sequence are in accord with what was predicted from the DNA sequence. Steady state kinetic parameters, effects of pH, salts, and inhibition constants of several anti-folates have been determined.

Optical perfect-shuffle-exchange interconnection network using a liquid-crystal spatial light switch

The perfect-shuffle-exchange interconnection network (e.g., the omega network) is a type of free-space regular multistage interconnection network. An equivalent omega network that consists of left- and right-perfect-shuffle interconnects as well as spatial light switch devices is described. An optical omega network that uses two special polarization prisms and a liquid-crystal spatial light switch is presented. The experimental results of a 8 x 8 omega network are reported. The optical omega network has the features of simple architecture and ease of integration.

Enhancement of the protective effect of inactivated influenza virus vaccine by cytokines

The authors examined whether or not cytokines in conjunction with inactivated influenza virus vaccine enhance protection from influenza virus infection in mice. Mice were infected with influenza virus A/PR/8/34 (PR/8) at 10 LD50 by nebulizer after intranasal administration of the cytokine and the vaccine. The survival rate of the group which received both the vaccine and mouse recombinant interferon-beta (MuIFN-beta; 1 x 10(4) IU/mouse) or mouse recombinant interferon-gamma (MuIFN-gamma; 1 x 10(4) IU/mouse) was significantly higher than that of the control group given the vaccine alone. These results show that MuIFN-beta and MuIFN-gamma have an adjuvant effect on this vaccination. In contrast, human recombinant interleukin-2 (HuIL-2) and human recombinant tumour necrosis factor (HuTNF) did not have an adjuvant effect. In order to examine the mechanism of the enhancing effect of MuIFN-gamma on this vaccination, we determined the specific IgA and IgG antibodies present in bronchoalveolar lavage fluid (BALF) and serum, and haemagglutination inhibition (HI) antibody in serum. In the early stage of infection, the titres of IgA and IgG antibodies in the combined group receiving the vaccine with MuIFN-gamma showed a tendency to be higher than those in the group given the vaccine alone. In the late stage of infection, the titre of HI antibody in the group given the vaccine with MuIFN-gamma was significantly lower than that in the group given vaccine alone. It can be concluded from these results that a part of the adjuvant effect of MuIFN-gamma on this vaccination was due to an increase in production of antibodies which neutralized the virus in the lesion.

Treatment of Staphylococcus aureus nasal carriers in CAPD with mupirocin

We have studied the efficacy of topical Mupirocin for elimination of Staphylococcus aureus (Staph. aureus) nasal carriage in CAPD patients. Staph. aureus nasal carriers in our CAPD program were randomized to one of two groups: Group 1, treated with Mupirocin, and Group 2, treated with neomycin sulphate nasal ointment. The prevalence of Staph. aureus nasal colonization was 44% for patients (24/54) and 17% for dialysis partners (5/29). Group 1 included 11 patients and 1 partner, and Group 2, 8 patients and 2 partners. In Group 1, the eradication rate was 100%, and the recolonization rate was 0, 8, 41, 55 and 66% at 1, 2, 3, 6 and 10 months. In Group 2, the eradication rate was 40%, with a recolonization rate of 0.25 and 75% at 1, 2 and 3 months. Re-treatment with mupirocin was successful in 66% of the cases, compared to 20% for neomycin. The MIC90 of mupirocin for Staph. aureus was 0.5 mcg/mL, with an increase to 4 mcg/mL towards the end of the study. During the study period, there was a very low incidence of Staph. aureus peritonitis or catheter-related infections in patients treated with mupirocin. Secondary effects of mupirocin were negligible. Mupirocin is more effective than neomycin sulphate for the elimination of Staph. aureus nasal colonization in patients undergoing CAPD. Periodic re-treatment is frequently necessary, given the significant recolonization rate.

[A comparison between antigliadin antibodies and blood xylose in celiac disease]

We have compared serum antigliadin antibodies (AGA) with xylose absorption test in diagnosis and follow-up of pediatric celiac disease. Three groups of children were investigated: celiacs, affected by other gastrointestinal disease, healthy controls. On gluten diet AGA IgA, IgG and xylose test were abnormal in all celiac children. After only three months of gluten-free diet, abnormal AGA IgA values were found in 3%, AGA IgG in 63%, xylose test in 28% of children. Normal values for AGA IgA and IgG and for xylose test were found between 7 and 20 months. On challenge, after 1-4 months of gluten diet, abnormal AGA IgA and IgG values were found in 90% of cases, xylose test only in 27%. As far as the children with other gastrointestinal disease are concerned, 2% had abnormal values for AGA IgA, 22% for AGA IgG and 42% for xylose test. All healthy children had normal AGA IgA, IgG values and xylose test. Our date show AGA IgA the most specific laboratory test, among these investigated, for diagnosis and follow-up of celiac disease.

Low frequency hearing threshold determination in newborns, infants and mentally retarded children by middle latency responses

Middle latency (10-50 ms) responses (MLR) evoked by tone-pips (1,000 Hz 500 Hz) and early (0-10 ms) auditory evoked potentials (EAEP) evoked by chicks were recorded on 68 newborn babies (premature or at term), infants and children, some with central nervous system or psychiatric disorders, who had normal or impaired hearing. MLR were obtained either during sleep, chloral-hydrate sedation or ketamine anesthesia. Thresholds estimated from MLR and EAEP were compared to those from subsequent psychoacoustic pure tone testing. We confirm that MLR provide good threshold estimates for hearing in the low frequency range, whereas click evoked EAEP are good threshold indicators only for high frequencies.

Isolation and expression of the Pneumocystis carinii dihydrofolate reductase gene

Pneumocystis carinii dihydrofolate reductase (DHFR; 5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) cDNA sequences have been isolated by their ability to confer trimethoprim resistance to Escherichia coli. Consistent with the recent conclusion that P. carinii is a member of the Fungi, sequence analysis and chromosomal localization show that DHFR is neither physically nor genetically linked to thymidylate synthase. Expression of recombinant P. carinii DHFR in heterologous hosts provides an abundant source of the enzyme that may form a basis for the development of new therapies for this enigmatic pathogen. Studies with the recombinant enzyme show that trimethoprim is a very poor inhibitor of P. carinii DHFR and, in fact, is a more potent inhibitor of human DHFR.

Enhancing effects of immunoactive peptide FR48217 on immunological responses to vaccination by inactivated influenza virus

The adjuvant effect of an immunoactive peptide, FR48217 (FR), was investigated in mice vaccinated with inactivated influenza virus with and without FR (designated as V + FR and V - FR, respectively). Mice were infected with influenza virus A/PR/8/34 28 days after vaccination. The survival rate indicated a strong adjuvant effect of FR on vaccination with inactivated influenza virus. No difference in interferon activity in the pulmonary lavage fluid was found between the V + FR and V - FR groups. The titres of virus-specific IgA and IgG antibodies in the serum increased after vaccination in both V + FR and V - FR groups and were significantly higher in the V + FR group than in the V - FR group. On days 2 and 4 after viral infection, the serum antibody titres decreased sharply and then increased again rapidly. The free IgA and IgG antibody levels in the pulmonary lavage fluid of vaccinated mice started to increase after day 4. It is proposed that one of the mechanisms by which FR has the adjuvant effect on vaccination is the increase of virus-specific IgA and IgG antibodies in the serum, which are diffused into the infection sites of the epithelial tissues in the respiratory tract to neutralize the virus at the early stages of viral infection.

Rapid detection of cutaneous herpes simplex virus infection with the polymerase chain reaction

A simple and specific method for detecting herpes simplex virus infection in routinely processed paraffin-embedded biopsy specimens is described. DNA is extracted from paraffin blocks, and subjected to DNA amplification with the polymerase chain reaction. After 40 rounds, an amplified band can be detected after agarose gel electrophoresis and ethidium bromide staining. This band is specific for herpes simplex virus, because tissues infected with related viruses do not give this amplified band. We have been able to detect viral DNA in small punch skin biopsies with this procedure, which can take as little as 6 h.