Factors associated with rifampin resistance in staphylococcal periprosthetic joint infections (PJI): a matched case-control study.

PURPOSE: Rifampin combination therapy plays an important role in the management of staphylococcal periprosthetic joint infection (PJI). However, the emergence of rifampin resistance is a feared complication. We retrospectively analysed predetermined potential risk factors in patients with rifampin-resistant staphylococcal PJI in a multicentre case-control study. METHODS: Cases (n = 48) were defined as PJI caused by rifampin-resistant staphylococci. Rifampin-susceptible controls (n = 48) were matched for microorganism and type of prosthetic joint. Uni- and multivariable conditional logistic regression analyses were performed to estimate odds ratios (OR) with 95 % confidence intervals (95 % CI). RESULTS: Forty-eight cases (31 men; median age 67 years; age range 39-88 years) with hip- (n = 29), knee- (n = 13), elbow- (n = 4), shoulder- (n = 1) or ankle-PJI (n = 1) were enrolled in the study. Staphylococcus aureus and coagulase-negative staphylococci were isolated in ten and 38 episodes, respectively. Most of the cases (n = 44, 92 %) had a previous PJI, and 93 % (n = 41) of these had been treated with rifampin. There was an independent association of emergence of rifampin resistance with male sex (OR 3.6, 95 % CI 1.2-11), ≥ 3 previous surgical revisions (OR 4.7, 95 % CI 1.6-14.2), PJI treatment with high initial bacterial load (inadequate surgical debridement, <2 weeks of intravenous treatment of the combination medication; OR 4.9, 95 % CI 1.6-15) and inadequate rifampin therapy (OR 5.4, 95 % CI 1.2-25). CONCLUSIONS: Based on our results, extensive surgical debridement and adequate antibiotic therapy are needed to prevent the emergence of rifampin resistance.

Factors associated with positive blood cultures in outpatients with suspected bacteremia.

Blood cultures are routinely taken in outpatients with fever and suspected bacterial infections. However, in the majority of cases, they are not informative and of limited value for clinical decision making. The aim of this study was therefore to investigate factors associated with positive blood cultures in outpatients presenting to an outpatient clinic and emergency room. This was a case-control study of all outpatients with positive blood cultures from January 1, 2006 to October 31, 2007 and matched control patients with negative blood cultures in the same time period. Microbiology results and medical charts were reviewed to determine factors associated with positive blood cultures. The presence of a systemic inflammation response syndrome (SIRS) (OR 2.7, 95% Cl 1.0-7.2) and increased C-reactive protein (CRP) (OR 1.1 per 10 mg/l, 95% Cl 1.0-1.2) were the most powerful predictive values for the development of positive blood cultures. In positive cases serum albumin was lower (35 mg/l versus 39 mg/l) than in controls. SIRS, increasing CRP and low albumin were associated with positive blood cultures in outpatients. With simple clinical assessment and few laboratory tests indicative of infection, it is possible to define a group at higher risk for bacteremia in outpatients.

Is phosphorus recovery from waste water feasible?

Phosphorus (P) recovery from waste water must become a predominant goal of all countries to face the limited resources of this essential nutrient. The induced crystallisation of calcium phosphates straight from the waste water phase applying tobermorite-rich calcium silicate hydrate compounds (CSH) from the construction industry as the trigger material has proved to be a suitable method. Laboratory and semi-technical scale experiments were carried out in fixed bed, stirred reactor and expanded bed mode. P-loads of the crystallisation substrates of up to 13 wt-% total P (P-tot) (30 wt-% P2O5) were achieved. Recycling options of the generated products, both as substitute for phosphate rock in the phosphate industry and as a new fertiliser in agriculture, were demonstrated. Indicative operating and investment costs were estimated for conversion of conventional waste water treatment plants (WWTP) designed for nutrient removal and P-precipitation with iron and aluminium reagents to the proposed new crystallisation technology for simultaneous P-removal and P-recovery.

[Antiviral treatment of influenza in humans]. / Antivirale Medikamente zur Behandlung und Prophylaxe der Influenza.

Antiviral agents are the most effective treatment option for influenza. Two classes of drugs are available, the adamantanes and the neuraminidase inhibitors. Neuraminidase inhibitors were a major breakthrough in the treatment options for influenza and were licensed in the year 2000. They have an excellent safety profile and effectively reduce viral shedding, symptoms, duration of illness, secondary complications, hospitalizations and consumption of antibiotics. Patients have also shown a more rapid return to everyday activities. The therapeutic efficacy is highly dependent on the time between the onset of symptoms and the starting of therapy. Very early initiation is primordial to have a maximal effect. Neuraminidase inhibitors are also effective in primary and secondary prophylaxis during epidemic influenza. They are a key point in the pandemic preparedness. Resistance to neuraminidase inhibitors does occur but has not become an extensive problem so far.

Phosphorus removal and recovery from wastewater by tobermorite-seeded crystallisation of calcium phosphate.

Investigations were focused on the development of a technology for phosphorus (P) recovery straight from wastewater. Facing the finiteness of the natural resources of this essential nutrient, the declared goal must be the sustainable use of available phosphorus sinks such as wastewater treatment plants (WWTP) for the generation of P rock substitutes. A feasible method for simultaneous elimination and recovery of phosphorus from wastewater proved to be the P-RoC process - the phosphorus recovery from wastewater by induced crystallisation of calcium phosphate, applying tobermorite-rich waste compounds of the construction industry. The experiments were performed in fixed bed-, stirred- and expanded bed reactors in laboratory--as well as in pilot-scale experiments. The efficiency and longevity of the P-RoC process was determined by the supply of Ca ions and the initial P concentration. Total P (P-tot) contents in the generated crystallisation products of up to 13% P-tot (30% P2O5) were achieved. Mineralogical investigations proved the formation of a hydroxy-apatite-(HAP)-like coating onto the seed material's surface. Reuse options for the generated crystallisation products, such as substitute for phosphate rock or as new fertiliser, were assessed.

Phosphate elimination and recovery from wastewater by active filtration using crushed gas concrete.

Laboratory long-term upstream fixed-bed experiments were carried out to investigate the efficiency of phosphorus elimination with the effluent of a biological sewage treatment plant using crushed gas concrete. The development of the pH-value in the column outflow as well as the reaction kinetics was investigated. Furthermore, the phosphorus yield was balanced for phosphorus recovery and the calcium phosphate compounds generated were specified by mineralogical analysis methods. These activities were followed by a study with respect to the suitability of the material as raw material for the phosphate industry.

[Worms and the lung]. / Der Wurm in der Lunge.

Due to international travel and migration helminthic infections are increasingly imported to countries were they are not endemic. A vast variety of helminthes may involve the lung. The lungs are either site of the infection or temporarily involved during maturation of helminthic larvae. In many affected patients the clinical picture is not specific and not typical. A thorough patient's history including a detailed travel history will lead to diagnosis, which must be confirmed by detecting the parasite either directly or with serological tests. The appropriate method depends on the parasite suspected and its life cycle within the human body. A combination of these methods will show the best results for most helminthes. As specific therapy is widely available for most helminthiases a precise diagnosis is important.

The Fas receptor in HIV infection: expression on peripheral blood lymphocytes and role in the depletion of T cells.

OBJECTIVE: To analyse the role of the apoptosis-inducing Fas receptor in the depletion of CD4+ and CD8+ T cells in HIV-infected individuals. METHODS: Peripheral blood lymphocytes (PBL) obtained from HIV-infected subjects of all 1993 Centers for Disease Control and Prevention (CDC) stages and from non-infected controls were examined. A two-colour cytofluorometry was employed using monoclonal antibodies against Fas receptor (CD95) in combination with the surface markers CD4, CD8, CD28, CD26 and CD45RO. CD4+ and CD8+ T-cell-enriched PBL were used as target cells to assess their susceptibility to lysis by CD4+ cytotoxic T lymphocytes (CTL) which kill via the Fas pathway. RESULTS: Fas+PBL are more elevated in HIV-infected individuals than in HIV-negative controls and increase significantly from CDC stages A to C. Whereas Fas+CD4+ and Fas-CD4+ T-cell populations decline in parallel with the progression of HIV infection, the Fas+CD8+, but not of the Fas-CD8+ fraction, significantly increases. The Fas+CD8+ lymphocytes are susceptible to Fas-mediated lysis as they are efficiently killed by Fas-ligand+CD4+CTL. CONCLUSION: The Fas receptor may contribute, but not as a unique cause, to the decline of CD4+ T cells in HIV-infected individuals. This and the significant increase of the number of Fas+ CD8+ T cells indicates that Fas-mediated immune regulation is disturbed.

Effects of cilazapril on vascular structure and function in essential hypertension.

Hypertension is associated with an altered design of resistance vessels and decreased endothelium-dependent vasodilator response to acetylcholine. A role of angiotensin II in both defects is suggested by animal experiments in which angiotensin-converting enzyme inhibition reverted structural and functional changes. We investigated the effects of 20 weeks of therapy with the angiotensin-converting enzyme inhibitor cilazapril (5 mg twice daily) on the endothelium-dependent response to brachial artery infusions of acetylcholine and the endothelium-independent vascular relaxation after sodium nitroprusside in 22 subjects with mild to moderate essential hypertension. In addition, we measured minimal forearm vascular resistance (ratio of mean arterial pressure and forearm blood flow after heating, ischemia, and ischemic exercise) as an indirect estimate of vascular structure. Cilazapril decreased blood pressure (151 +/- 14/99 +/- 7 mm Hg during placebo to 138 +/- 17/89 +/- 8 mm Hg after cilazapril treatment, P<.01) and baseline (42.2 +/- 12.6 to 37.1 +/- 10.6 U, P<.05) and minimal (3.0 +/- 1.1 to 2.4 +/- 0.7 U, 15.9 +/- 20.2%; P<.05) forearm vascular resistances. The change in minimal forearm vascular resistance was unrelated to age, duration of hypertension, or changes in blood pressure. Sodium nitroprusside increased forearm blood flow from 2.6 +/- 1.0 to 11.4 +/- 5.9 mL/min per 100 mL and acetylcholine to 21.5 +/- 17.8. Both responses did not change after cilazapril. The data provide indirect evidence that cilazapril therapy may improve vascular structure in human hypertension. The lack of relationship between vascular and blood pressure changes would be compatible with experimental evidence supporting a role for angiotensin II in the development and regression of vascular changes, but this needs further study. Therapy with cilazapril for 20 weeks, like other antihypertensive therapy, does not seem to influence endothelial vasodilator function in humans to a significant degree.

A comparison of efficacy and specificity of three NK depleting antibodies.

This study compares in vivo efficacy and specificity of the three NK cell depleting antibodies anti-asialo GM1, anti-NK 1.1 and the recently described TM beta 1, which is directed against the interleukin-2 receptor beta chain. All three antibodies are equally efficacious as assessed by abolishing NK mediated cytolytic activity induced by a high dose virus infection or Poly IC against YAC-1 targets. Similarly, the generation of virus-specific cytotoxic T cells (CTL) was unimpaired after NK depletion in two different virus infections. However, if mice are treated with the antibodies several days after virus infection, when strong CTL responses have already been generated, anti-asialo GM1 and-to a lesser extent-also TM beta 1 have a significant effect on CTL activity. Only after treatment with anti-NK 1.1 antibody, CTL activity was not significantly impaired. We conclude, that of the NK depleting antibodies currently available, anti-NK 1.1 allows the best differentiation of activated CTL and NK cells in vivo.

Thrombocytopenia after kidney transplantation.

We report a case of posttransplant malaria in which the patient developed progressive thrombocytopenia after receiving living related donor kidney transplantation. The donor, who flew in from Sri Lanka for the procedure, had suffered from malaria 18 months earlier. Malaria should be suspected in transplant patients receiving organs from donors originating from countries with a high prevalence of malaria.

Hospital admissions for malaria in Basel, Switzerland: an epidemiological review of 150 cases.

The increase in international travel and immigration from tropical countries has led to a growing number of imported malaria cases in industrialized countries. We analyzed the charts of every patient hospitalized for malaria from 1970-1992 in Basel, Switzerland. A period lasting from 1970-1986 was compared to 1987-1992. There were 150 malaria-episodes recorded. Over time, the number of immigrants increased from 12 to 27% (p <.05). More patients were admitted with Plasmodium falciparum-infection (49 vs. 75%, p <.005). The number of untypable malaria decreased from 30 to 9% (p <.005). In the more recent period, more diagnosis were done within a week (66 vs. 50%, p <.05). Twenty-three (15%) patients were admitted to the ICU, four (2. 6%) patients died of cerebral malaria. Twenty-seven (18%) patients developed malaria while taking correct prophylaxis. Despite some progress, malaria is still causing considerable morbidity and mortality. Non adherence to chemoprophylaxis was a major risk factor for acquiring malaria in hospitalized patients.

Plasma and urine carnitine concentrations in well-trained athletes at rest and after exercise. Influence of L-carnitine intake.

L-carnitine is essential to cellular energy production mainly because of its acyl- and acetyl-carrier properties. Athletes commonly take L-carnitine, which is thought to improve exercise performance. There are no reports on carnitine plasma concentrations and carnitine excretion in short-duration maximal exercise in well-trained athletes taking this substance. We measured plasma and urine carnitine concentrations before and 10 min after maximal treadmill ergometry in nine well-trained sportsmen with and without oral supplementation with 1 g L-carnitine. In athletes without L-carnitine intake, plasma free carnitine concentration decreased significantly from 45.2 +/- 5.3 to 41.6 +/- 5.0 mumol/l (mean +/- SD, p < 0.001) 10 min after exercise compared with baseline. In athletes with oral L-carnitine supplementation, plasma free carnitine concentration at baseline was 71.3 +/- 10.2 mumol/l and did not change after maximal exercise (71.8 mumol/l +/- 10.7 mumol/l). The elevated plasma concentration of free carnitine without decrease after maximal exercise in well-trained athletes taking L-carnitine could be important in view of the newly postulated direct vascular effects of L-carnitine in improving skeletal muscle performance.

Relation between insufficient response to antihypertensive treatment and poor compliance with treatment: a prospective case-control study.

OBJECTIVES: To prospectively compare compliance with treatment in patients with hypertension responsive to treatment versus patients with treatment resistant hypertension. DESIGN: Prospective case-control study. SETTING: Outpatient department in a large city hospital in Switzerland, providing primary, secondary, and tertiary care. PARTICIPANTS: 110 consecutive medical outpatients with hypertension and taking stable treatment with at least two antihypertensive drugs for at least four weeks. MAIN OUTCOME MEASURES: Treatment compliance assessed with MEMS devices; blood pressure determined by 12 hour daytime ambulatory monitoring (pressure <135/85 mm Hg in patients aged 60 indicated hypertension responsive to treatment). RESULTS: Complete data were available for 103 patients, of whom 86 took >/=80% of their prescribed doses ("compliant") and 17 took <80% ("non-compliant"). Of the 49 patients with treatment resistant hypertension, 40 (82%) were compliant, while 46 (85%) of the 54 patients responsive to treatment were compliant. CONCLUSION: Non-compliance with treatment was not more prevalent in patients with treatment resistant hypertension than in treatment responsive patients.

[Headaches and aphasia in an immunocompromised patient]. / Kopfschmerzen und Wortfindungsstörungen bei einem immunsupprimierten Patienten.

We report the case of a 81-year-old, immunocompromised Patient, admitted to our hospital with new-onset headaches and word-finding difficulties. The MRI of the brain revealed a temporal mass on the left with marginal contrast-enhancement. During the next days Listeria monocytogenes grew in the bloodcultures so that the diagnosis of a brain-abscess caused by Listeria was established. Due to the localisation, surgical drainage of the abscess was not possible, so that a prolonged antibiotic therapy lasting over 4.5 months was initiated. The MRI after therapy demonstrated no abscess persistence. Listeria mostly cause infections in the immunocompromised, elderly, newborn or pregnant host. Next to bacteraemia without a focus, CNS-invasion with meningitis, meningoencephalitis or less frequent abcess-formation (5-10%) is the most important manifestation.

[Tuberculous lymphadenitis]. / Zervikale Lymphknotenschwellung.

We report a case of a 49-year-old woman from the Philippines, who has been living for many years in Switzerland, with chronic unilateral swelling of the cervical lymphnodes. After the serological exclusion of several microorganisms, a fine needle aspiration was performed without conclusive result. However, patient history and a strongly positive PPD skin test were highly suspicious for tuberculous lymphadenitis, which was finally confirmed by lymphnode biopsy on histopathological and cultural workup. Therefore tuberculostatic treatment was initiated for 6 months.

[Hyperprolactinemia in a man's world]. / Hyperprolaktinämie - in a man's world.

A 60-years old patient was admitted for mamillary pain for several weeks, without galactorrhea. Erectile dysfunction had been present for several years but diminished libido had developed only recently. Ultrasonography of the mamillary gland was not definite for gynecomastia but repeated serum prolactin concentrations were elevated 5-fold the upper limit of normal. Furthermore serum level of testosterone was decreased and levels of luteinizing hormone and follicle-stimulation hormone were within normal range. Magnetic resonance imaging (MRI) of the pituitary gland could not identify a tumoral mass. In review of the laboratory features and the absence of a tumoral mass on MRI, idiopathic hyperprolactinemia was diagnosed and therapy with a dopamine-agonist was started.