The role of chloride anion and CFTR in killing of Pseudomonas aeruginosa by normal and CF neutrophils

Chloride anion is essential for myeloperoxidase (MPO) to produce hypochlorous acid (HOCl) in polymorphonuclear neutrophils (PMNs). To define whether chloride availability to PMNs affects their HOCl production and microbicidal capacity, we examined how extracellular chloride concentration affects killing of Pseudomonas aeruginosa (PsA) by normal neutrophils. PMN-mediated bacterial killing was strongly dependent on extracellular chloride concentration. Neutrophils in a chloride-deficient medium killed PsA poorly. However, as the chloride level was raised, the killing efficiency increased in a dose-dependent manner. By using specific inhibitors to selectively block NADPH oxidase, MPO, and cystic fibrosis transmembrane conductance regulator (CFTR) functions, neutrophil-mediated killing of PsA could be attributed to three distinct mechanisms: CFTR-dependent and oxidant-dependent; chloride-dependent but not CFTR- and oxidant-dependent; and independent of any of the tested factors. Therefore, chloride anion is involved in oxidant- and nonoxidant-mediated bacterial killing. We previously reported that neutrophils from CF patients are defective in chlorination of ingested bacteria, suggesting that the chloride channel defect might impair the MPO-hydrogen peroxide-chloride microbicidal function. Here, we compared the competence of killing PsA by neutrophils from normal donors and CF patients. The data demonstrate that the killing rate by CF neutrophils was significantly lower than that by normal neutrophils. CF neutrophils in a chloride-deficient environment had only one-third of the bactericidal capacity of normal neutrophils in a physiological chloride environment. These results suggest that CFTR-dependent chloride anion transport contributes significantly to killing PsA by normal neutrophils and when defective as in CF, may compromise the ability to clear PsA.     

Probing in vivo Mn2+ speciation and oxidative stress resistance in yeast cells with electron-nuclear double resonance spectroscopy

Manganese is an essential transition metal that, among other functions, can act independently of proteins to either defend against or promote oxidative stress and disease. The majority of cellular manganese exists as low molecular-weight Mn²⁺ complexes, and the balance between opposing “essential” and “toxic” roles is thought to be governed by the nature of the ligands coordinating Mn²⁺. Until now, it has been impossible to determine manganese speciation within intact, viable cells, but we here report that this speciation can be probed through measurements of ¹H and ³¹P electron-nuclear double resonance (ENDOR) signal intensities for intracellular Mn²⁺. Application of this approach to yeast (Saccharomyces cerevisiae) cells, and two pairs of yeast mutants genetically engineered to enhance or suppress the accumulation of manganese or phosphates, supports an in vivo role for the orthophosphate complex of Mn²⁺ in resistance to oxidative stress, thereby corroborating in vitro studies that demonstrated superoxide dismutase activity for this species.     

Allergy to insect sting : III. Allergenic cross-reactivity among the vespid venoms

Recent reports have indicated that venoms may be more beneficial than whole body extracts for the diagnosis and treatment of Hymenoptera sensitive patients. These studies were undertaken to determine the cross-reactivity among the vespid venoms. Eighteen patients who were anaphylactically sensitive to vespid venoms were studied using in vitro leukocyte histamine release. The results (venom concentration for 50% histamine release) were analyzed by linear regression analysis; there was no allergenic cross-reactivity between any of the venoms, except for a modest association between yellow hornet and white hornet venom. In spite of this result 13 of the 18 patients studied were sensitive to three or four of the venoms tested. There is no clear explanation for this observation, but it suggests the existence of multiple major allergens in the vespid venoms, some of which are cross-reactive. Since immunotherapy with inappropriate proteins may lead to the development of IgE and the possibility of clinical sensitivity and since the majority of patients were not sensitive to all venom preparations, we suggest that appropriate diagnostic studies be carried out before the institution of therapy.     

Prospective observations on stopping prolonged venom immunotherapy

After a decade spent establishing the safety, efficacy, and optimal techniques for venom immunotherapy, we have begun a series of studies to determine how long venom immunotherapy must be continued. In retrospective surveys, patients who had stopped venom immunotherapy after 1 to 2 years had a substantial risk (25%) of systemic sting reactions, but this was less than 50% of the risk in untreated patients. In this first prospective study, 30 patients elected to stop venom immunotherapy after at least 5 years of therapy. Skin test sensitivity had decreased significantly during therapy in 18/30 patients but remained clearly positive in 23/30 (seven patients became equivocal or negative). Serum venom-specific IgE antibodies were at the lower limit of detection (1 ng/ml) in 11/30 patients. After stopping treatment, the mean serum venom-specific IgG antibody level declined from 5.5 +/- 0.6 micrograms/ml to 2.4 +/- 0.3 micrograms/ml by 9 months, which is the same as the mean venom IgG in untreated patients. After 12 months without therapy, live sting challenge caused no systemic reaction in 29 patients. The mean venom IgG level 1 month after the sting had risen significantly to 4.1 +/- 0.5 micrograms/ml, but there was no significant increase of venom IgE. These results suggest that prolonged venom immunotherapy leads to isotype-specific suppression of the venom IgE antibody response and may provide persistent clinical protection by mechanisms other than IgG blocking antibodies. The observations are to be interpreted very cautiously. Further investigations are needed to extend these observations in additional patients and for longer periods of time, and to examine possible mechanisms for this apparent loss of clinical reactivity.     

Effect of magnesium supplementation containing mineral bishofit (MgCl2 x 6H2O) solution and pyridoxine hydrochloride on erythrocyte magnesium depletion and behaviour of rats after three-month alcoholization.

In therapy it is known that the combination of vitamin B6 and magnesium is beneficial in the treatment of several forms of primary magnesium deficiency. The purpose of the present study was to investigate the effect of complex magnesium supplementation containing mineral bishofit solution (MgCl2 x 6H2O) and pyridoxine hydrochloride on behavioural and biochemical parameters of magnesium-deficient alcoholic rats. A complex magnesium supplementation containing mineral bishofit solution and pyridoxine hydrochloride led both to restoration of magnesium level, and to some correction of behavioural disturbances of animals during chronic alcoholization.     

A case of maple syrup urine disease misdiagnosed as Tetanus neonatorum on admission

A case of Maple Syrup Urine Disease (MSUD) is presented with clinical signs and symptoms on admission resembling neonatal tetanus. Diagnosis had to be differentiated between MSUD and other metabolic disorders and neonatal infections (especially neonatal tetanus because of severe opisthotonos) and generalized seizures of the patient. Early diagnosis of the MSUD patient is very important for effective therapy and better long-term prognosis as well as genetic counselling and prenatal diagnosis for future pregnancies.     

THE CASH NEXUS: OR HOW THE THERAPEUTIC FEE IS A FORM OF COMMUNICATION

ABSTRACT Money is significant in many relationships, including that of psychotherapy. Yet within analytic writing it is often neglected. The early writings of Freud and Ferenczi are somewhat limited in identifying its potential importance, compared perhaps with Winnicott's exploration of its transactional significance within an object relations framework. Perhaps surprisingly, the early philosophical writings of Karl Marx, as he struggled to understand the symbolic importance of money in terms of its power to represent alienation and objectification, indicate a possible way of developing further understanding. The paper illustrates some of these points with two clinical case discussions.