Effect of Phenolic Acids and Esters on Respiration and Reproduction of Bacteria in Urine

Vanillic, syringic, gallic, and protocatechuic acids, methyl-p-hydroxybenzoate, and propyl-p-hydroxybenzoate generally inhibited respiration in vitro of Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, and Aerobacter aerogenes in human urine. In the absence of any other available carbon source, certain of the phenolic compounds were utilized. Reproduction was generally suppressed in urine buffered to pH 7, 5.6, 4.5, and 4.0. The phenolic compounds were used in the range of 0.11 to 0.99 μmole/ml.     

In vitro differentiation of rabbit blastocyst cells

Summary Six- and seven-day post-coitus (p.c.) rabbit embryos have been cultured in an attempt to establish a trophectodermal cell line. Results indicate that cells with epithelial characteristics (i.e. positive staining for cytokeratin) will survive in culture until Passage 3. At that time a fibroblastlike cell becomes predominant. In addition, we have found that the presence of the inner cell mass is required for embryo explants often results in the development of cells that spontaneously contract. These cells stain positively for myosin, which indicates that they may be precardiac cells. Maximum diastolic potential was −59±1.2 mV and the threshold potential was −53±2.3 mV. Spontaneously contracting cells did not respond to atropine, acetylcholine, epinephrine, isoproterenol, or propranolol. Action potential seems to be a result of an inward calcium current, because the beating rate is decreased in a dose-related manner with the calcium channel blocker verapamil, whereas the voltage-sensitive sodium channel blocker tetrodotoxin was without effect. This work was supported by grants HD21302, HD07069, DK31091, and HL37320 from the National Institutes of Health, Bethesda, MD, with additional support from a University of Alabama at Birmingham Cardviovascular Research and Training Center Award.     

Medicolegal considerations in the initiation and termination of resuscitation in Canada.

Medicolegal issues in cardiopulmonary resuscitation (CPR) and emergency cardiac care were considered in the United States by the National Conference on Cardiopulmonary Resuscitation in 1985. This paper discusses these issues in the Canadian context. Although there is little legislation or case precedent in Canada to guide providers of CPR in decision-making, there appears to be little risk of liability or prosecution for competently rendered care. Providers should be cautious in withholding or withdrawing resuscitative measures from incompetent patients when brain death has not occurred and cardiovascular unresponsiveness has not been demonstrated. However, resuscitation may be withheld when a competent patient refuses it or if there is another medically and legally valid reason to do so.     

Complement phenotypes in patients with psoriasis

Phenotype frequencies for the complement proteins C4A, C4B, Bf (factor B) and C3 were performed for 49 Caucasian patients with psoriasis. The C4*A6 allele was present in 26.6% of the patients as compared to 5.4% of healthy regional Caucasian controls, p less than 0.001, relative risk = 6.28. The C4*A6 allele is known to be in linkage disequilibrium with the HLA B17 allele and to produce a non-functional gene product when it occurs with the B17 allele. HLA B17 is known to be associated with psoriasis in many Caucasian populations. Additional findings in the present study were a significant reduction in the C4B*2 allele frequency, a non-significant increase in the Bf*F allele frequency and no difference for Bf or C3 phenotype frequencies in the patients with psoriasis as compared to the controls.     

Combined effects of interferon α and interleukin 2 on the induction of a vascular leak syndrome in mice

Summary Immunotherapy with interleukin 2 (IL-2) alone or in combination with lymphokine-activated killer cells can mediate tumor regression in mice and in man. Further dose escalation of IL-2 along with lymphokine-activated killer cells has been prevented by the development of a vascular leak syndrome produced by IL-2. Because we have found that interferon (IFN-) or tumor necrosis factor (TNF-) has synergistic antitumor effects when administered together with IL-2, we have tested the vascular leakage induced by these lymphokine combinations. We used a murine model to quantify vascular leakage by measuring the extravasation of ¹²⁵I-albumin from the intravascular space as well as the wet and dry lung weights after treatment with different cytokines. Cytokines (or Hanks balanced salt solution) were administered to C57BL/6 mice and 4 h after the last injection the vascular leak was quantified. IFN- alone did not cause extravasation of radiolabel or increase in wet lung weights, though when given in combination with IL-2, significantly greater extravasation (P<0.01) as well as increase in lung water weights (P<0.05) was observed compared to the response in mice treated with IL-2 alone. IFN- in combination with IL-2 induced significant vascular leakage earlier than the response induced by IL-2 alone. For example treatment with IFN- and IL-2 induced accumulation of 14674±605 cpm in the lungs at day 1 while IL-2 alone induced 12340±251 cpm. The degree of vascular leakage was highly related to the dose of IFN- administered along with IL-2 and increased vascular leak syndrome was evident even at low doses (5000 units) of IFN-. Immunosuppression of mice by pretreatment irradiation (500 rad) markedly decreased the development of vascular leak syndrome induced by IL-2 and IFN-. Interestingly IFN- and TNF- did not induce vascular leakage in the lungs when given alone, and did not add or synergize with IL-2 in causing the syndrome. Thus the administration of IFN- in combination with IL-2 produces a dose-limiting vascular leakage that is more severe than that caused by IL-2 alone, and may be mediated, directly or indirectly by host radiosensitive cells. Abbreviations used: LAK, lymphokine-activated killer; IFN, interferon; TNF, tumor necrosis factor; IL-2, interleukin-2     

Chromosomal localization of ARSB,the gene for human N-acetylgalactosamine-4-sulphatase

Summary A deficiency of N-acetylgalactosamine-4-sulphatase (G4S, gene symbol ARSB), results in the accumulation of undegraded substrate and the lysosomal storage disorder, Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI). In situ hybridization using an ³H-labelled human G4S genomic DNA fragment to human metaphase chromosomes localized ARSB to chromosome 5q13–5q14. This location is consistent with, an refines, previous chromosomal assignments based on the expression of human G4S in somatic cell hybrids.     

Comparison of the nucleotide and amino acid sequences of the RsrI and EcoRI restriction endonucleases

The RsrI endonuclease, a type-II restriction endonuclease (ENase) found in Rhodobacter sphaeroides, is an isoschizomer of the EcoRI ENase. A clone containing an 11-kb BamHI fragment was isolated from an R. sphaeroides genomic DNA library by hybridization with synthetic oligodeoxyribonucleotide probes based on the N-terminal amino acid (aa) sequence of RsrI. Extracts of E. coli containing a subclone of the 11-kb fragment display RsrI activity. Nucleotide sequence analysis reveals an 831-bp open reading frame encoding a polypeptide of 277 aa. A 50% identity exists within a 266-aa overlap between the deduced aa sequences of RsrI and EcoRI. Regions of 75-100% aa sequence identity correspond to key structural and functional regions of EcoRI. The type-II ENases have many common properties, and a common origin might have been expected. Nevertheless, this is the first demonstration of aa sequence similarity between ENases produced by different organisms.     

Tumor-specific cytolysis by lymphocytes infiltrating human melanomas

Tumor infiltrating lymphocytes (TIL) were grown in IL-2 from single cell tumor suspensions of 14 human melanomas resected from 12 patients. As a function of time in culture, 4 of 14 TIL cultures eventually expressed highly specific cytolytic activity against fresh autologous melanoma targets in short term chromium release assays, failing to lyse multiple allogeneic tumors or autologous normal cells. These highly specific TIL were identified as CTL by phenotype (CD3+/CD4-/CD8+/Leu7-) and by function (lysis inhibited by antibodies directed against CD3 and MHC class I molecules). Cell separation experiments using immunomagnetic beads identified a highly tumor-specific CTL subpopulation within a nonspecific TIL culture, suggesting that the lytic activity of tumor-specific CTL may be diluted by the nonspecific killer activity present in heterogeneous TIL cultures. These studies provide evidence for specific MHC-restricted human immune responses against autologous tumor in cancer-bearing patients, and may be of importance to ongoing clinical trials using TIL in the immunotherapy of advanced malignancies.