Sciatic neuritis as initial symptom of spontaneous clostridial myonecrosis.

A 21-year-old woman is reported with aplastic anaemia, who presented with pain in the leg. Rapid loss of sciatic nerve function followed. MRI showed irregular streaks of low intensity in the muscles of the pelvic region. A diagnosis of sciatic neuritis as initial symptom of clostridial myonecrosis was made.     

Cyclic GMP release and vasodilatation induced by EDRF and atrial natriuretic factor in the isolated perfused kidney of the rat.

1. Guanosine 3':5'-cyclic monophosphate (cyclic GMP) release and vascular tone was measured in the isolated kidney of the rat perfused at constant flow with Krebs-Henseleit solution. The effects of 3 vasodilators, acetylcholine (ACh), atrial natriuretic factor (ANF) and sodium nitroprusside (SNP) on the renal release of cyclic GMP and vascular tone were examined. The ability of the endothelial-derived relaxing factor (EDRF) inhibitors, haemoglobin and gossypol, to modify vasodilatation and vasodilator-induced changes in cyclic GMP releases from the kidney was also investigated. 2. Renal cyclic GMP release was elevated 8 fold by ANF (0.01 microM), 5 fold by SNP (1 microM) and 3 fold by ACh (0.3 microM). 3. For ACh, both the increase in renal cyclic GMP release and the vasodilatation were reduced by the EDRF inhibitors, haemoglobin (1 microM) and gossypol (15 microM). For SNP, neither the increase in renal cyclic GMP release nor vasodilatation were inhibited by gossypol (15 microM). 4. For ANF, neither the increase in cyclic GMP release from the kidney nor its vasodilator activity were affected by haemoglobin (1 microM). 5. EDRF inhibitors reduced the basal release of cyclic GMP from 0.32 +/- 0.06 pmol min-1 to 0.18 +/- 0.03 pmol min-1, gossypol being more effective than haemoglobin. 6. The results are consistent with the ability of ACh to induce EDRF-mediated vasodilatation in the isolated perfused kidney of the rat. Basal EDRF release appears to contribute approximately 50% to the basal release of cyclic GMP from this preparation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Atriopeptins and nitroprusside provoke opposite changes in cGMP and cAMP levels in human macrophages.

Atrial natriuretic factor (ANF, 10(-7) M) and, even more potently, sodium nitroprusside (SNP, 10(-5)-10(-3) M) stimulated cGMP formation in human peritoneal macrophages. This suggests that the two forms of guanylate cyclase, the particulate form stimulated by ANF and the soluble form activated by SNP, coexist in this cell type. A fall in cAMP levels in parallel with the rise of cGMP levels provoked by ANF and SNP was noticed that was amplified by an increase in the concentration of the phosphodiesterase inhibitor, IBMX. Our finding that ANF, contrary to its action in other tissues, was unable to exert direct inhibitory effects on the adenylate cyclase activity in isolated macrophage membranes, together with the observation that SNP was able to mimic the effect of ANF on cAMP levels indicates that the cAMP-lowering effect of ANF is most likely mediated through the cGMP signal.     

Topoisomerase I inhibitors: the relevance of prolonged exposure for present clinical development.

Topoisomerase I inhibitors constitute a new class of anti-cancer agents. Recently, topotecan and irinotecan were registered for clinical use in ovarian cancer and colorectal cancer respectively. Cytotoxicity of topoisomerase I inhibitors is S-phase specific, and in vitro and in vivo studies have suggested that, for efficacy, prolonged exposure might be more important than short-term exposure to high concentration. Clinical development of those topoisomerase I inhibitors that have reached this stage is also focused on schedules aiming to achieve prolonged exposure. In this review, we summarize all published preclinical studies on this topic for topoisomerase I inhibitors in clinical development, namely 20-S-camptothecin, 9-nitro-camptothecin, 9-amino-camptothecin, topotecan, irinotecan and GI147211. In addition, preliminary data on clinical studies concerning this topic are also reviewed. The data suggest that prolonged exposure may indeed be relevant for anti-tumour activity. However, the optimal schedule is yet to be determined. Finally, clinical data are yet too immature to draw definitive conclusions.     

Chequerboard titrations: the influence of the composition of serial dilutions of antibiotics on the fractional inhibitory concentration index and fractional bactericidal concentration index

Chequerboard titrations carried out with modified serial dilutions of antibiotics such that consecutive concentrations in these series were four times smaller than those in two-fold serial dilutions enable MICs and MBCs to be determined with greater accuracy. Interaction indices calculated by this method can differ markedly from those calculated on the basis of two-fold serial dilutions. The differences calculated in this study ranged from -0.30 to +1.06.     

Design and application of sensor for recording sounds over human eye and nose

The recording of sounds over the oribt of the eye has been found to be useful in the detection of intracranial aneurysms. A hydrophone for auscultation over the eye has been developed and is tested under controlled conditions. The tests consist of measurement over the eyes in three healthy volunteers at rest, during voluntary breathing, during eyeball movements and during sustained orbicular muscular contractions. Furthermore, measurements are performed at the side of the nose. Major features of the hydrophonic transducer are high sensitivity to physiological sounds and a high degree of insensitivity to environmental sounds propagated through the air. It can be concluded that the hydrophone may be useful for the early detection of intracranial aneurysms and also for apnoea detection.     

Functional activity of antibodies against the recombinant OpaJ protein from Neisseria meningitidis

The opacity proteins belong to the major outer membrane proteins of the pathogenic Neisseria and are involved in adhesion and invasion. We studied the functional activity of antibodies raised against the OpaJ protein from strain H44/76. Recombinant OpaJ protein was obtained from Escherichia coli in two different ways: cytoplasmic expression in the form of inclusion bodies followed by purification and refolding and cell surface expression followed by isolation of outer membrane complexes (OMCs). Immunization with purified protein and Quillaja saponin A (QuilA) induced high levels of Opa-specific antibodies, whereas the E. coli OMC preparations generally induced lower levels of antibodies. Two chimeric Opa proteins, hybrids between OpaB and OpaJ, were generated to demonstrate that the hypervariable region 2 is immunodominant. Denatured OpaJ with QuilA induced high levels of immunoglobulin G2a (IgG2a) in addition to IgG1, whereas refolded OpaJ with QuilA induced IgG1 exclusively. These sera did not induce significant complement-mediated killing. However, all sera blocked the interaction of OpaJ-expressing bacteria to CEACAM1-transfected cells. In addition, cross-reactive blocking of OpaB-expressing bacteria to both CEACAM1- and CEA-transfected cells was found for all sera. Sera raised against purified OpaJ and against OpaJ-containing meningococcal OMCs also blocked the nonopsonic interaction of Opa-expressing meningococci with human polymorphonuclear leukocytes.     

Detection by polymerase chain reaction of Treponema pallidum DNA in cerebrospinal fluid from neurosyphilis patients before and after antibiotic treatment.

A polymerase chain reaction with nested primer pairs based on the DNA sequence of the 39-kDa bmp gene of Treponema pallidum subsp. pallidum is described. The method allowed the detection of purified T. pallidum DNA equivalent to the amount of DNA in a single bacterium and was specific for T. pallidum subspecies. After concentration of DNA, using diatomaceous earth, it was possible to detect about 100 treponemes in 1 ml of cerebrospinal fluid. Cerebrospinal fluid samples from a total of 29 symptomatic and asymptomatic patients with neurosyphilis were tested for the presence of treponemal DNA before and at various intervals after intravenous treatment with penicillin. Prior to the penicillin treatment, we detected T. pallidum DNA in 5 of 7 patients with acute symptomatic neurosyphilis, in none of the 4 patients with chronic symptomatic neurosyphilis tested before treatment, and in 2 of 16 patients with asymptomatic neurosyphilis. Unexpectedly, T. pallidum DNA was also often detected in cerebrospinal fluid long after intervenous treatment with penicillin, sometimes up to 3 years after therapy.     

Sequential Measurements of Chemokines in Urosepsis and Experimental Endotoxemia

Chemokines are a superfamily of small chemotactic proteins. While increased levels of interleukin-8 have been measured in serum and urine during urinary tract infection, little is known about other chemokines in this condition. Monocyte chemoattractant protein (MCP)–1, macrophage inflammatory protein (MIP)–1, MIP-1 and interferon- inducible protein (IP)–10 were measured in 30 patients with culture-proven urosepsis during a 3-day follow-up and in 11 healthy humans after intravenous injection of endotoxin (4 ng/kg). Urine and serum levels of MCP-1, MIP-1, and IP-10, but not of MIP-1, were elevated in patients on admission, and decreased after initiation of antibiotic treatment. Endotoxin administration to healthy subjects induced increases in plasma and urine concentrations of all four chemokines. These data indicate that clinical and experimental gram-negative infection in humans is associated with enhanced production of chemokines that act mainly on mononuclear cells and that these chemokines are at least in part locally produced.     

Activation of ion transport by combined effects of ionomycin,forskolin and phorbol ester on cultured HT-29cl.19A human colonocytes

The differentiated clone 19A of the HT-29 human colon carcinoma cell line was used as a model to study the intracellular electrophysiological effects of interaction of the cAMP, the protein kinase C (PKC) and the Ca²⁺ pathways, (a) A synergistic effect between ionomycin and forskolin was observed. From intracellular responses it was concluded that the synergistic effect is caused by activation of an apical Cl^– conductance by protein kinase A and a basolateral K⁺ conductance by Ca²⁺. (b) A transient synergistic effect of ionomycin and the phorbol ester phorbol dibutyrate (PDB) was found. The decrease of the response appeared to be due to PKC-dependent inactivation of the basolateral K⁺ conductance. The synergism is caused by PKC-dependent increase of the apical Cl^– conductance and Ca²⁺-dependent increase of the basolateral K⁺ conductance. (c) The effects of carbachol and PDB were not fully additive presumably because of their convergence on PKC activation, (d) Forskolin and PDB, when added in this order, had a less than additive effect. Results of cell-attached patch-clamp studies, presented in the accompanying paper, showed a synergistic effect of forskolin and PDB on non-rectifying small-conductance Cl^– channels. Assuming that these channels are involved in the transepithelial responses it is suggested that forskolin and PDB induce a modulatory, synergistic increase of the apical Cl^– conductance when both pathways are activated simultaneously. (e) The HT-29cl.19A cells differ from T₈₄ cells in that the latter did not respond with an increase of the short-circuit current to addition of phorbol ester. This may be due to a very low expression of PKC.