Identification of a conjugative plasmid carrying antibiotic resistance and salmonella plasmid virulence (spv) genes in epidemic strains of Salmonella typhimurium phage type 193

A plasmid pDEP34 that codes for resistance to ampicillin, streptomycin, sulphonamides and tetracyclines has been identified in strains of Salmonella typhimurium phage type 193 which have become increasingly common in England and Wales since 1988. pDEP34 is also self-conjugative, carries the genes responsible for the virulence of host strains for BALB/c mice ( spv genes) and is closely related to the Salm. typhimurium 'serotype-specific' plasmid pSLT.     

The effects of warming by active and passive means on the subsequent responses to cold water immersion

Two experiments were undertaken to investigate the effects of warming the body upon the responses during a subsequent cold water immersion (CWI). In both experiments the subjects, wearing swimming costumes, undertook two 45-min CWIs in water at 15° C. In experiment 1, 12 subjects exercised on a cycle ergometer until their rectal temperatures (T _re) rose by an average of 0.73°C. They were then immediately immersed in the cold water. Before their other CWI they rested seated on a cycle ergometer (control condition). In experiment 2, 16 different subjects were immersed in a hot bath (40° C) until their T _re rose by an average of 0.9° C; they were then immediately immersed in the cold water. Before their other CWI they were immersed in thermoneutral water (35° C; control condition). Heart rate in both experiments and respiratory frequency in experiment 1 were significantly (P < 0.05) higher during the first 30 s of CWI following active warming. In experiment 1, the rate of fall of T _re during the final 15 min of CWI was significantly (P < 0.01) faster when CWI followed active warming (2.46° C · h^–1) compared with the control condition (1.68°C · h^–1). However, this rate was observed when absolute T _re was still above that seen in the control CWIs. It is possible, therefore, that if longer CWIs had been undertaken, the two temperature curves may have converged and thereafter fallen at similar rates; this was the case with the aural temperature (T _au) seen in experiment 1 and the T _au and T _re in experiment 2. It is concluded that pre-warming is neither beneficial nor detrimental to survival prospects during a subsequent CWI.     

Characteristics of the core protein of the aggregating proteoglycan from the Swarm rat chondrosarcoma

A ternary complex of hyaluronic acid-binding region and link protein bound to hyaluronic acid was isolated from limit clostripain digests of proteoglycan aggregates isolated from the Swarm rat chondrosarcoma. Under these conditions, the hyaluronic acid-binding region has a molecular weight of ? 65,000 (HA-BR₆₅). N-terminal amino acids in the complex were selectively ^l4C-carbamylated. The resulting derivatized HA-BR₆₅ was isolated, and tryptic peptide maps were prepared and developed on two-dimensional TLC sheets. A single, labeled peptide was obtained which gave a M_r by ? 8,000 by SDS-PAGE. Chymotrypsin digestion of the ternary complex reduced the molecular weight of HA-BR₆₅ to a polypeptide of ? 55,000 (HA-BR₅₅) which still retains the same N-terminal tryptic peptide. Partial digestion of proteoglycan aggregates with clostripain generated a series of larger intermediates with the hyaluronic acid-binding region. Direct SDS-PAGE analysis revealed one major intermediate with M_r ? 109,000 (HA-BR₁₀₉) as well as HA-BR₆₅. After chondroitinase digestion, two additional prominent intermediates were observed on a SDS-PAGE gel at M_r ? 120,000 (HA-BR₁₂₀) and ? 140,000 (HA-BR₁₄₀). All the intermediates were recognized by a monoclonal antibody specific for the hyaluronic acid-binding region, and all of them contained the same N-terminal tryptic peptide. The results indicate that the N terminus of the core protein is at the hyaluronic acid-binding end of the proteoglycan and that the chondroitin sulfate chains are first present on the core protein in a region between 109,000 and 120,000 molecular weight away from the N terminus.     

Home care for patients with suspected myocardial infarction: use made by general practitioners of a hospital team for initial management.

Two hundred and sixty three general practitioners were offered the use of a hospital based service consisting of a medical senior house officer, a nurse attached to a coronary care unit, and a specially equipped ambulance estate car to help with the initial management of patients with suspected myocardial infarction who might be suitable for home care. One hundred and sixty nine general practitioners registered as potential users of this service; during 22 months they called the hospital team to see 271 patients, 235 of whom the team suspected had indeed suffered a myocardial infarction. During the same period, however, these general practitioners also admitted 317 patients with suspected myocardial infarction directly to hospital. Other general practitioners admitted 323 patients and deputising doctors 258. A further 529 patients with suspected infarction were admitted without the intervention of a general practitioner. Of the patients seen by the team, 54 required immediate admission to hospital; 17 of the remaining patients who initially appeared suitable for home care later required admission to hospital. In a large city such as Nottingham the provision of hospital based facilities to help general practitioners with home management is unlikely to make an appreciable impact on the overall pattern of care of patients with suspected myocardial infarction.     

Serological identification of group D streptococci using commercial antisera

Three commercial group D streptococcal antisera were tested for the serological identification of 100 group D enterococci; 20 Streptococcus bovis; 5 isolated from each of the following streptococcal groups: A, B, C and G; and 3 isolates from serological group F. Antisera from Difco Laboratories, BBL, and Wellcome Reagents Limited were used in the classic capillary tube precipitin test on extracts prepared using the Rantz and Randall procedure. No false positive precipitin reactions were observed. Of the enterococcal isolates, all 100 reacted with the Wellcome, 99 reacted with the BBL, and 96 reacted with the Difco group D antisera. However, of the 20 S. bovis isolates, only 2 reacted with the BBL, and 1 reacted with both the Difco and the Wellcome antisera. Each antiserum was then used to prepare staphylococcal coagglutination (CoA) reagents and each isolate was subsequently tested. A simple extraction procedure was performed by suspending colonies of an isolate in a loopful of salin on a microscope slide and gently heating the slide directly in the flame of a Bunsen burner. All 100 enterococci and all 20 S. bovis gave positive results with the BBL and the Wellcome CoA reagents. Using the Difco reagent, 2 S. bovis isolates failed to produce postitive results. No false positive results were observed with the non-Group D isolates. Our results indicate that the CoA technique using commercial group D antisera may provide faster and sometimes more sensitive serological identification than the classic capillary tube precipitin test.     

Characterization and mapping of microdissected genomic clones from the adenomatous polyposis coli (APC) region.

The gene associated with adenomatous polyposis coli (APC) has been mapped to the long arm of chromosome 5. To saturate the APC region with DNA markers, two independent microdissection libraries with an emphasis on 5q21.2-21.3 and 5q22 have been constructed from GTG-banded human metaphase chromosomes. PCR-amplified insert DNA of the primary amplificate used as a probe in chromosomal in situ suppression (CISS) hybridization of human metaphase spreads revealed region-specific signals at the chromosomal site that was excised for cloning. One hundred forty-two inserts, derived from both libraries, have been characterized in more detail. Deletion mapping analysis was performed with 17 single-copy clones on a hamster-human hybrid cell panel. Seven of these clones were located within two interstitial deletions of 6-8 Mb from APC-affected individuals around chromosome bands 5q21-22. The identification of new microclones mapping into these deletions and their use in isolating YAC clones should contribute to the construction of a contiguous physical map of the APC region.     

PR39, a peptide regulator of angiogenesis

Although tissue injury and inflammation are considered essential for the induction of angiogenesis, the molecular controls of this cascade are mostly unknown. Here we show that a macrophage-derived peptide, PR39, inhibited the ubiquitin-proteasome-dependent degradation of hypoxia-inducible factor-1alpha protein, resulting in accelerated formation of vascular structures in vitro and increased myocardial vasculature in mice. For the latter, coronary flow studies demonstrated that PR39-induced angiogenesis resulted in the production of functional blood vessels. These findings show that PR39 and related compounds can be used as potent inductors of angiogenesis, and that selective inhibition of hypoxia-inducible factor-1alpha degradation may underlie the mechanism of inflammation-induced angiogenesis.     

Neisseria lactamica attenuates TLR-1/2-induced cytokine responses in nasopharyngeal epithelial cells using PPAR-γ

The upper respiratory tract commensal Neisseria lactamica (Nlac) induces protective humoral immunity against pathogenic Nmen serogroup B (Nmen), but whether it also affords anti-inflammatory mucosal protection, as reported for several gut commensals, has not been investigated. Here we demonstrate for the first time that Nlac weakly induces inflammatory responses compared with Nmen in the nasopharyngeal epithelial cell line, Detroit 562, and that Nlac achieves this by attenuation of secretory cytokine (TNF-α and IL-6) and to a lesser extent chemokine (IL-8 and RANTES) responses. Culture of Detroit cells with Nlac inhibited the induction of cytokine-chemokine mRNA by Nmen, reduced Nmen-induced NF-κβ activity and increased constitutive PPAR-γ protein expression. Pretreatment of Detroit cells with a PPAR-γ antagonist abrogated the attenuation of inflammatory IL-6 by Nlac, as did heat-killing of the organisms and preventing their invasion with cytochalasin D. Inflammatory responses from Detroit cells were readily attenuated by Nlac following stimulation with pathogenic Nmen but more specifically following stimulation with the TLR-1/2 agonist Pam3Cys and pro-inflammatory cytokines (IL-1β, TNF-α) but not LTA or LPS. These results indicate that Nlac plays an important role in suppressing pathogen-induced inflammation in the nasopharyngeal mucosa, mediated through TLR-1/2 stimulation, by activating PPAR-γ and inhibiting NF-κβ activity.     

Dose dependent radiation-induced hypotension in the canine

Radiation-induced early transient incapacitation (ETI) is often accompanied by severe systemic hypotension. However, postradiation hypotension does not occur with equal frequency in all species and is not reported with consistency in the canine. In an attempt to clarify the differences in reported canine postradiation blood pressures, canine systemic blood pressures were determined both before and after exposure to gamma radiation of either 80 Gy or 100 Gy. Data obtained from six sham-radiated beagles and 12 radiated beagles indicated that 100 Gy, whole-body, gamma radiation produced a decrease in systemic mean blood pressure while 80 Gy, whole-body, gamma radiation did not. Analysis of this data could be consistent with a quantal response to a gamma radiation dose between 80 Gy and 100 Gy.