Suppression of cellular immune activity following severe head injury

Infection is a major cause of morbidity following multiple traumatic and head injury. Although immunosuppression has been demonstrated after multiple traumatic injury, the effects of head injury on immune function have not been thoroughly investigated. In a prospective study of 10 severely head-injured patients, in vitro and in vivo parameters of cellular immune activity were assessed. In vitro measurements of lymphocyte surface antigen expression following mitogen stimulation were made serially over a 3-week period in 10 patients with severe head injury. The control group consisted of 20 healthy subjects. Phenotyping of peripheral blood lymphocytes (PBLs) was performed following incubation with and without mitogens. Phenotypes were determined by flow cytometry using monoclonal antibodies (MABs) to T lymphocyte subsets and the alpha subunit of interleukin 2 (IL-2) receptors. In vivo cellular immune function was determined by measuring patient responses to delayed-type hypersensitivity (DTH) skin testing within 24 h of injury. When head-injured patients were compared to controls, PBLs incubated in the presence of phytohemagglutinin (PHA) demonstrated a decrease in cells marking as T cells (p = 0.005), helper-inducer T cells (p = 0.001), and in the number of IL-2 receptor-bearing cells (p = 0.001). The functional ability of these lymphocyte subpopulations to proliferate in the presence of PHA was significantly suppressed within 24 h of injury and normalized within 3 weeks of injury. DTH skin testing to Candida, mumps, trichophyton, and PPD antigens was performed within 24 h of injury and resulted in anergic responses in all 10 patients when measured at 24, 48, and 72 h following administration. The overall infection rate was 60%, with the majority of infections occurring within the first 4 days following injury. The results of this study indicate that severe head injury results in suppression of cellular immune function with a corresponding high rate of infection. The possible significance of the decrease in the percentage of helper-inducer T cells and in the number of cells bearing IL-2 receptors following mitogen stimulation is discussed.

Characterization, cloning, curing, and distribution in lactic acid bacteria of pLP1, a plasmid from Lactobacillus plantarum CCM 1904 and its use in shuttle vector construction

A small 2.1-kb plasmid called pLP1 was extracted from Lactobacillus plantarum CCM 1904 (ATCC 8014) and cloned into the Escherichia coli pUC19 plasmid. As determined by DNA-DNA Southern hybridization with a pLP1-radioactively labeled probe, other lactic acid bacteria such as L. curvatus, L. sake, Carnobacterium, and Leuconostoc mesenteroides harbor pLP1-related plasmids. Shuttle vectors based on the pLP1 replicon were constructed by inserting the erythromycin-resistance gene from pVA891 into the various pUC19-pLP1 constructions. pLP1-based shuttle vector transformation efficiencies (TE) by electroporation were compared to TE of a broad-host-range plasmid pGK12 in different lactobacilli strains. Expression of the pUC19-pLP1 plasmids in Escherichia coli maxicells showed that pLP1 encodes for a 37,000 MW protein which can act in trans allowing the replication of plasmids in which this protein is truncated. The pLP1-based shuttle vectors producing this protein replicate in lactobacilli and also in Bacillus subtilis. A pLP1-free strain was obtained by incompatibility with a pLP1-based shuttle vector introduced in L. plantarum CCM 1904 by electroporation. The absence of pLP1 has no incidence on the strain phenotype suggesting that pLP1 is not essential for the strain in our laboratory conditions.

Structural organization of pLP1, a cryptic plasmid from Lactobacillus plantarum CCM 1904

To construct shuttle vectors based on an endogenous replicon, we isolated a small cryptic plasmid (pLP1) from Lactobacillus plantarum CCM 1904. The nucleotide sequence (2093 bp, 38.25 GC mol%) revealed one major open reading frame encoding for a 317 amino acid protein (Rep). Comparisons with proteins encoded by other Gram-positive bacteria plasmids strongly suggest that the protein encoded by pLP1 has a replicative role. The presence of a consensus sequence including a tyrosine residue known to be the replication protein binding site to the DNA (in phage phi X174) strengthens this hypothesis. The DNA sequence contains also a sequence similar to the pC194 origin nick sequence, which initiates the plasmid replication at the plus origin, characteristic of plasmids which replicate following a rolling circle mechanism via single-stranded DNA intermediates. A set of 13 direct repeats of 17 bp could be involved in the expression of the incompatibility or in the copy number control as in the other plasmids. A promoter sequence located at the rep 5' region has been identified and is functional in Bacillus subtilis.

Long-term observation following traumatic-hemorrhagic shock in the dog: a comparison of crystalloidal vs. colloidal fluids

The effect of volume replacement with crystalloidal and colloidal solutions was analyzed in 40 anesthetized Foxhounds subjected to a standardized traumatic-hemorrhagic shock. Following trauma and hypotension (MAP 40 mmHg; 3.0 +/- 0.5 hr) the animals were randomized to treatment with autologous blood and hydroxyethyl starch 6% (HES 450/0.7), or human serum albumin 5% (ALB), dextran-60 6% (DX), Ringer's lactate (RL), and hyperosmolar saline 1.3% (HS), respectively. While analgesia and sedation were maintained, the hemodynamic measurements were continued for a 24-hr period. Crystalloids and colloids were found equally effective in maintaining the macrohemodynamics following resuscitation from traumatic-hemorrhagic shock. To keep central hemodynamics at pre-shock level required at least four times higher volumes of crystalloids than colloids. No specific advantage for one of the substitutes tested was found with regard to accumulation of water in the lung during the first 24 hr following shock in dogs. Extravascular lung water (thermo-dye) and organ water (gravimetry) were not different between the groups. However, fluid loss into the abdominal cavity as well as albumin extravasation into lung interstitium and abdominal cavity were more pronounced in the crystalloid-treated animals, whereas albumin redelivery by the lymph was decreased. The deterioration of tissue oxygen extractions as well as the changes in acid-base balance in both crystalloid-treated groups reflect the persistent microcirculatory inhomogeneity in spite of normal macrohemodynamics.

Emission from ionic cesium fluoride excimers excited by a laser-produced plasma

CsF vapor generated in a heat pipe was excited by a laser-produced plasma. Temporally integrated spectra and time-resolved fluorescence on the ionic excimer transition Cs(2+)F(-) ? Cs(+)F were observed at 185 nm. The pressure dependence of the fluorescence is influenced by self-absorption in the CsF vapor. The fluorescence is assigned to the Cs(2+)F(-) ((2)Sigma(1/2), B)? Cs(+)F ((2)Sigma(1/2),X) transition.

In vivo allergen tachyphylaxis in guinea pig lung is mediated by endogenous prostaglandin E biosynthesis

The term "allergen tachyphylaxis" (AT) describes a progressively decreased bronchial reactivity to allergen exposition after repeated allergen challenge [in our test system measured by sequential inhalative antigen challenge of sensitized guinea pigs (GP)]. The hypothesis that AT is mediated by endogenous prostaglandin E (PGE) biosynthesis was tested in vivo on GP sensitized to ovalbumin (OA). Different groups of animals were challenged with simultaneous inhalation of OA (repeatedly at time 0, 10, 20, 60 and 70 min) together with inhibitors of PGE-biosynthesis ( parachloromercurobenzoic acid = PCMB, copper sulfate = Cu, copper dithiotreitol complex = CuDTT , dithiotreitol = DTT and dimercaptopropanol = DMP) or agents increasing PGE production (aurothioglucose = Au, zinc dithiotreitol complex = ZnDTT and reduced glutathion = GSH). Bronchial obstruction was measured by whole body plethysmography . PCMB, Cu, CuDTT , DTT and DMP inhibited AT, whereas Au and ZnDTT enhanced AT. Acetylsalicylic acid (ASA) treatment prevented AT. Aerosols of PGE2, but not of prostacyclin or prostaglandin D2 restored AT in ASA treated animals. In addition to these in vivo experiments in vitro investigations showed that PCMB, Cu and DTT decreased while ZnDTT increased PGE biosynthesis of allergen challenged GP lungs. It is concluded that AT, an important self-protecting mechanism of GP bronchial asthma, is mediated at least in part via endogenous PGE.

Allergen tachyphylaxis of guinea pigs in vivo; a prostaglandin E mediated phenomenon?

Ovalbumin (OA) sensitized guinea pigs were repeatedly challenged with 1% OA in saline nebulized ultrasonically at the 0, 10, 20, 60 and 70th min. The intensity of bronchial obstruction was measured by body plethysmography. The first three challenges (0. 10, 20 min) caused strong asthmatic reactions in all animals, the last two (60, 70 min) only mild one in 10 out of 15 animals. The development of this "tachyphylaxis" was markedly reduced by pretreatment of the animals with cyclooxygenase inhibitors (indomethacin 10 mg/kg intraperitoneally resp, acetylsalicylic acid 10 mg/kg orally 2 h before tests). The effect of both inhibitors (i.e. inhibition of tachyphylaxis) was abolished by supplementing prostaglandin E2 as aerosol simultaneously to the allergen (100-200 ng per inhalation). The results suggest that allergen tachyphylaxis we have observed in vivo might be due to synthesis of cyclooxygenase products, e.g. prostaglandin E.

[Anti-platelet-aggregation drugs and atherosclerosis]

The relationship between hyperlipidaemia and thrombophilic state in atherosclerosis was appraised by evaluation of platelet aggregation according to Breddin in 20 patients with clinically established atherosclerosis, 10 normal controls, and 22 subjects taken from the average population of a medical department aged 12-58 yr with no history of atherosclerosis. Normal screening for the disease was carried out in all patients. Drugs inhibiting platelet-aggregation were given to all subjects in Breddin's 3rd or 4th stage. A relationship was noted between Breddin stage and the seriousness of atherosclerosis, while the former was a pointer to thrombophilic states. The drugs administered were able to reverse the aggregation stage.