Serum markers for fibrosis and plasma transforming growth factor-β1 in patients with hepatocellular carcinoma in comparison with patients with liver cirrhosis

In order to elucidate collagen metabolism in hepatocellular carcinoma (HCC) tissue, we compared levels of different potential markers of collagen metabolism and plasma transforming growth factor-β₁ in patients with HCC and in patients with liver cirrhosis. Serum levels of prolyl hydroxylase and the tissue inhibitor of metalloproteinase-1 in patients with HCC were significantly higher than those in patients with liver cirrhosis and increased with the size of the HCC tumour, whereas the serum levels of procollagen type III propeptide and type IV collagen 7S domain were similar in the two groups. In HCC, the increased plasma transforming growth factor-β₁ levels were closely correlated with serum levels of prolyl hydroxylase and the tissue inhibitor of metalloproteinase-1. These findings suggest that, in HCC tissue, the intracellular biosynthesis of collagen is enhanced, whereas the secretion of procollagen is disturbed and the degradation of collagen is suppressed by the excess production of the tissue inhibitor of metalloproteinase-1. The results also suggest that plasma transforming growth factor-β₁ plays an important role in the altered metabolism of collagen in HCC.     

Induction of antibody responses to breast carcinoma associated mucins using synthetic peptide constructs as immunogens

A strategy for directing and enhancing B cell immune responses against synthetic peptide determinants has been developed in order to produce antibodies specifically against protein epitopes of clinical relevance. A peptide sequence based upon the MUC-1 mucin protein core was selected for this purpose since anti-MUC-1 antibodies have proven diagnostic application and therapeutic potential in human breast and ovarian cancer. Peptide constructs were synthesised co-linearly linking the immunodominant B cell determinant region, PDTRPAP, in the protein core of the MUC-1 mucin, to sequence 111 – 120 of influenza haemagglutinin A/X-31, a determinant recognised by T helper cells through association with MHC class II molecules. Induction of anti-MUC-1 antibodies to the B cell determinant region by immunisation with peptide was shown to be dependent upon both the presence and the position of the T cell determinant. In addition, haplotype mismatching with respect to the T cell determinant resulted in a significant lowering of the anti-MUC-1 antibody response in peptide construct immunised mice. These findings are relevant to the design of immunogens to produce antibodies against peptide epitopes of tumour associated proteins and glycoproteins.     

Guided bone regeneration for immediate non‐submerged implant placement using bioabsorbable materials in Beagle dogs

The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri‐implant defects after placement of non‐submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow‐screw non‐submerged dental implants. For each animal, the coronal peri‐implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site: 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures ( P >0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%. P <0.05) or sites grafted with HA (22.2%, P <0.02). Total BIC in sites treated with the HA‐membrane combination (43%) was only significantly different from sites treated with HA ( P <0.10). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained.     

Collagen abnormalities in the spinal cord from patients with amyotrophic lateral sclerosis

During the last 10 years, we have demonstrated morphological and biochemical abnormalities of skin extracellular matrices in amyotrophic lateral sclerosis (ALS). However, currently little is known concerning collagen of the spinal cord in ALS. We measured the amount of collagen and characterized collagen at light and electron microscopic levels in posterior funiculus, posterior half of lateral funiculus and anterior horn of cervical enlargement of the spinal cord obtained from ten patients with ALS, 11 patients with other neurologic diseases (control group A), and ten patients without neurologic ones (control group B). In posterior half of lateral funiculus and anterior horn, (1) by light microscopy, there was no significant difference in vessel wall area between ALS patients and control groups A and B; (2) ultrastructurally, collagen bundles were more fragmented and widely separated, and the fibrils were randomly oriented in the perivascular space of capillaries in ALS patients, which were not observed in any areas of control groups or in posterior funiculus of ALS patients; and (3) the collagen contents in ALS were significantly lower (P<0.001 and P<0.001, respectively) than those in control groups A and B. Fragmented and widely separated collagen bundles in the interstitial tissue surrounding capillaries and markedly decreased amount of collagen in posterior half of lateral funiculus and in anterior horn of ALS could be related to the degeneration of the upper and lower motor neurons in the spinal cord in ALS, that is, selective neuronal vulnerability in ALS.     

Peritonsillar abscess — Do we need anaerobic cover?

Objective To find out the usability and advantage with regard to the advent of new and more costly antibiotics. In the treatment of Peritonsillar abscess the demonstration of, both aerobic and anaerobic organisms has raised the question of possible need to treat with antibiotics effective against anaerobes. It was in this very context that this study was planned to find out if we still have an economically and easily available antibiotic to treat Peritonsillar abscess. Conclusions Injectable penicillin is the drug of choice in PTA as GABHS and staphylococcus aureus coagulase positive are the most common organism associated with this condition. Even where penicillin resistant organism is present, effective management of the abscess is possible if it is drained well and weak hydrogen peroxide gargles are used along with injectable penicillin.     

Diabetes alters μ and κ opioid binding in rat brain regions: comparison with effects of food restriction

Diabetic rats display changes in opioid pharmacology and brain regional levels of opioid peptides and prodynorphin mRNA. Previous investigations of opioid receptor binding, carried out in whole-brain homogenates, have, however, failed to detect changes. In the present study, quantitative autoradiography was used to measure μ and κ opioid receptor binding in discrete brain regions of streptozotocin-treated diabetic rats. Measurement was limited to regions that previously displayed opioid binding changes in chronically food-restricted rats, since our primary aim is to identify brain mechanisms that mediate adaptive responses to persistent metabolic need and adipose depletion. Diabetics displayed strong trends or statistically significant changes which matched seven of the thirteen binding changes observed in food-restricted rats. In no case did diabetics display changes in the opposite direction. The two statistically significant changes common to food-restricted and diabetic rats are increased κ binding in the medial preoptic area and decreased μ binding in the lateral habenula. The possible functional significance of these changes is discussed.     

INVOLVEMENT OF PHOSPHOPROTEIN PHOSPHATASE 1 IN COLLAGEN-PLATELET INTERACTION

The binding of type I collagen to its receptor initiates platelet aggregation, but the relationship of the receptor to other signal transduction components is not yet established. Correlation of platelet aggregation and anti-type I collagen receptor antibody immunoprecipitation of type I collagen treated [³²PO4]-labeled platelets showed that there are two phosphoproteins (M_r 53 kDa and 21 kDa) that coprecipitated with the 65 kDa platelet type I collagen receptor. In the present investigation, we have identified one of the phosphoproteins. A soluble component the 100,000×g supernatant fraction of 53 kDa protein is recognized by polyclonal anti-PP1 antibody. The activity of the precipitated phosphatase is inhibited by okadaic acid and inhibitor 1, suggesting that it is protein phosphatase 1 (PP 1). Phosphorylation decreases PP 1 activity as was found with [³²PO4]-phosphorylase b as the substrate. The immunocoprecipitation of the type-1 collagen receptor and PP 1 inot the result of cross reactivity of the anti-type I collagen receptor antibody with the PP I protein. These results indicate that the platelet type I collagen receptor, PP 1, and unidentified 21 kDa protein are in close association with the platelet type I collagen receptor upon the binding of type I collagen by the receptor. Copyright © 1996 Elsevier Science Ltd     

Synthetic peptides corresponding to the sequence of noxiustoxin indicate that the active site of this K+ channel blocker is located on its amino-terminal portion

Summary A nonapeptide Thr-Ile-Ile-Asn-Val-Lys-Cys-Thr-Ser (NTX_1–9) and a decapeptide Met-Asn-Gly-Lys-Cys-Lys-Cys-Tyr-Asn-Asn (NTX_30–39) corresponding to the N-terminal and C-terminal sequences respectively of Noxiustoxin (NTX) were synthesized by the solid phase method of Merrifield (1963). The first synthetic peptide (NTX_1–9) was shown to be toxic to mice independently of the route of administration: intraperitoneally, subcutaneously or intraventricularly (100–200 g/20 g mouse weight). The second (NTX_30–39) was not toxic even at higher dose (400 g/20 g mouse). When the effects of the peptide NTX_1–9 and of the authentic toxin (Noxiustoxin) were studied on the liberation of [³H] 4-aminobutyric acid (³H-GABA) from mouse synaptosomes, both gave essentially the same results, except that peptide NTX_1–9 was needed at higher concentration. Synthetic peptide NTX_30–39 had no effect in the same preparation at even higher doses. The GABA release produced by toxic peptide NTX_1–9 was not affected by tetrodotoxin but was completely abolished by the presence of the K⁺ ionophore valinomycin, mimicking the effect of native NTX in the same system (Sitges et al., 1986). These results indicate that the toxic active site of Noxiustoxin is possibly located in or near the N-terminal amino acid portion of the molecule.Abbreviations used BOC amino acids ter-butyloxycarbonyl-amino acids - BOC amino acid-PAM-resin ter-butyloxycarbonyl-aminoacyl-4-(oxymethyl)-phenacetamidomethyl-resin - GABA 4 aminobutyric acid - HPLC high performance liquid chromatography - MSA mouse serum albumin - NTX Noxiustoxin - NTX _(numbers) synthetic peptides with amino acid sequences of NTX at position start (first number) to position end (second number) of the sequence according to Fig. 1 - TTX tetrodotoxin Supported in part by the Mexican Council of Science and Technology (CONACyT), grants PVT/QF/NAL/84/2182, PVT/AI/NAL/85/3029 to L.D.P.; PCSACNA 022640 to A.B. A patent request claiming rights on the use of synthetic NTX and related peptides was presented in Washington, DC (U.S.A.), Serial number 07/132,169, filing date December 14, 1987.