Peptide conjugated chitosan foam as a novel approach for capture-purification and rapid detection of hapten--example of ochratoxin A.

A novel bioassay for the detection and monitoring of Ochratoxin A (OTA), a natural carcinogenic mycotoxin produced by Aspergillus and Penicillium fungi, has been developed and applied for the screening of red wine. Here we report the immobilization and orientation of NOF4, a synthetic peptide, onto 3-D porous chitosan supports using a N-terminal histidine tag to allow binding to M(++) ions that were previously adsorbed onto the high surface area biopolymer. Three divalent cations (M(++)=Zn(++), Co(++), Ni(++)) were evaluated and were found to adsorb via a Langmuir model and to have binding capacities in the order Zn(++)>Co(++)>Ni(++). Following Zn(++) saturation and washing, C-terminus vs. the N-terminus His-tagged NOF4 was evaluated. At 1000 µg L(-1) OTA the N-terminus immobilization was more efficient (2.5 times) in the capture of OTA. HRP labeled OTA was added to the antigen solutions (standards or samples) and together competitively incubated on biospecific chitosan foam. The chemiluminescence substrate luminol was then added and after 5 min of enzymatic reaction, light emission signals (λmax=425 nm) were analyzed. Calibration curves of %B/B0 vs. OTA concentration in PBS showed that half-inhibition occurred at 1.17 µg L(-1), allowing a range of discrimination of 0.25 and 25 µg L(-1). In red wine, the minimum concentration of OTA that the system can detect was 0.5 µg L(-1) and could detect up to 5 µg L(-1). Assay validation was performed against immunoaffinity column (IAC) tandem reversed-phase high pressure liquid chromatography with fluorescence detection (HPLC-FLD) and provided quite good agreement. The association of chitosan foam and specific peptide represents a new approach with potential for both purification-concentration and detection of small molecules. In the future this assay will be implemented in a solid-sate bioelectronic format.

A series of five adult cases of respiratory syncytial virus-related acute respiratory distress syndrome.

Respiratory syncytial virus is a common cause of respiratory tract disease in children, predominantly presenting with mild symptoms. We present five cases of respiratory syncytial virus infection of the lower respiratory tract in immunocompromised adults suffering from severe respiratory insufficiency leading to bilateral pneumonia and fulfilling the criteria for acute respiratory distress syndrome. Respiratory syncytial virus was cultured as the only pathogen in the bronchoalveolar lavage fluid in four of these patients. Despite various therapeutic interventions, only one patient survived. Respiratory syncytial virus was implicated as a direct cause of respiratory failure. Respiratory syncytial virus may be an underestimated cause of severe respiratory failure and acute respiratory distress syndrome in the immunocompromised adult admitted to the intensive care unit.

Selective ambulatory management of imported falciparum malaria: a 5-year prospective study.

The ambulatory management of imported Plasmodium falciparum malaria is controversial because criteria for safe selection of patients are imprecise. The aim of the present study was to investigate the evolution and outcome of patients diagnosed with Plasmodium falciparum malaria at a Belgian referral institute in order to assess the safety of the institute's current selective ambulatory management protocol. From 2000 to 2005, all patients diagnosed with P. falciparum infection at the Institute of Tropical Medicine and the University Hospital of Antwerp were enrolled prospectively. Ambulatory treatment was offered to nonvomiting patients if they exhibited none of the 2000 World Health Organization criteria of severity and had parasitemia below 1% at the initial assessment. The treatment of choice was quinine (plus doxycycline or clindamycin) for inpatients and atovaquone-proguanil for outpatients. P. falciparum malaria was diagnosed in 387 patients, of whom 246 (64%) were Western travelers or expatriates and 117 (30%) were already on antimalarial therapy. At diagnosis, 60 (15%) patients had severe malaria. Vital organ dysfunction was initially seen in 34 and developed later in five others. Five patients died. Of the 327 patients initially assessed as having uncomplicated malaria, 113 (35%) were admitted immediately; of these, 4 developed parasitemia >/=5% at a later stage but without any clinical consequence. None of the 214 individuals initially treated as outpatients experienced any malaria-related complications, including 10 who were admitted later. Vital organ dysfunction was observed in only 2 of the 214 patients with initial parasitemia <1% who had not taken antimalarial agents (both patients had impaired consciousness at presentation). Ambulatory treatment is safe in treatment-naive malaria patients with parasitemia <1% who do not vomit and who do not exhibit any criteria of severe malaria.

High-dose cefepime as an alternative treatment for infections caused by TEM-24 ESBL-producing Enterobacter aerogenes in severely-ill patients.

This study evaluated retrospectively the efficacy of treatment with cefepime vs. a carbapenem, in combination with amikacin or ciprofloxacin, for seriously-ill patients infected with ESBL-producing Enterobacter aerogenes who were admitted to an intensive care unit. Forty-four episodes of infection were investigated in 43 patients: 21 treated with cefepime; 23 with a carbapenem. The two treatment groups did not differ statistically in terms of age, APACHE II scores, and infection sites, but the average duration of antibiotic exposure was significantly shorter in the cefepime group (8.5 days vs. 11.4 days; p 0.04). Clinical improvement was seen in 62% of patients receiving cefepime vs. 70% of patients receiving a carbapenem (p 0.59). Bacteriological eradication was achieved in 14% of patients receiving cefepime vs. 22% of patients receiving a carbapenem (p 0.76). The 30-day mortality rates related to infection were 33% in the cefepime group and 26% in the carbapenem group (p 0.44). Thus, outcome parameters did not differ significantly between the two groups. Nevertheless, a statistically significant increase in failure to eradicate ESBL-producing E. aerogenes was observed as the MICs of cefepime rose (p 0.017). Pulsed-field gel electrophoresis revealed three distinct clones, but one predominant clone harbouring the bla(TEM-24) gene was associated with most (42/44) of the episodes of infection. It was concluded that cefepime may be an alternative agent for therapy of severe infections caused by TEM-24 ESBL-producing E. aerogenes, although further studies are required to confirm these observations.

Early diagnosis of cerebral fat embolism syndrome by diffusion-weighted MRI (starfield pattern).

BACKGROUND: Cerebral fat embolism syndrome is a rare, but potentially lethal, complication of long bone fractures. Neurological symptoms are variable, and the clinical diagnosis is difficult. The purpose of this case study is to demonstrate the value of diffusion-weighted MRI of the brain for early diagnosis of fat embolism syndrome. Case Description- A non-head-injured 18-year-old woman suffered acute mental status changes 21 hours after an uncomplicated fracture of the left tibia. MRI of the brain was performed 48 hours after injury. T2-weighted images showed multiple nonconfluent areas of high signal intensity, which, on the diffusion-weighted scans, were revealed as bright spots on a dark background ("starfield" pattern). We suggest that this indicates areas of restricted diffusion that are due to cytotoxic edema, resulting from multiple microemboli. CONCLUSIONS: High-intensity lesions in the brain on diffusion-weighted images may serve as an early-appearing and more sensitive indicator of the diagnosis of fat embolism in the clinical context of long bone injury without head trauma.

A cluster of airport malaria in Belgium in 1995.

In Europe 64 cases of airport malaria have been registered between 1969 and 1996, most of them in France, Switzerland and Belgium. In the summer of 1995 six cases of airport malaria occurred at the International airport of Brussels, Belgium. Of the six patients three were airport employees, three were occasional visitors. One patient died, the diagnosis was made by PCR amplification and DNA sequencing after exhumation. Two different species of Plasmodium were detected, and infections occurred on at least two different floors of the airport. An inquiry revealed that the cabin of airplanes is correctly sprayed, according to WHO recommendations, but that the inside of the hand luggage, the cargo hold, the animal compartment, the wheel bays and container flights remain possible shelters for infected mosquitoes. In a case of fever of unknown origin, airport malaria should be considered in the differential diagnosis, especially during hot summers, and when thrombocytopenia is present. Additional antimosquito measures should be generalised, encompassing highly exposed personnel, container content and handling buildings, animal cages, wheel bays, and the boundary between the sorting and the reception of luggage.

Splenic rupture as a complication of P. falciparum malaria after residence in the tropics. Report of two cases.

Splenic rupture is an uncommon complication of malaria, which requires urgent medical investigation, close follow-up and adequate treatment. Until present, this complication was reported more often in P. vivax infections than in infections with other species. Rupture can happen spontaneously or as a result of trauma, which may be minor and unnoticed. The diagnosis is made by physical examination, ultrasound and CT-scan. Especially in malaria endemic areas the management of splenic rupture in malaria should be focused on splenic preservation. We describe two cases of splenic rupture during a P. falciparum infection, both requiring finally splenectomy.

Exchange blood transfusion in severe falciparum malaria: retrospective evaluation of 61 patients treated with, compared to 63 patients treated without, exchange transfusion.

The rationale for exchange blood transfusion (ET) in severe falciparum malaria is threefold: reduction of parasitaemia, reduction of presumptive 'toxic' factors, and improvement of the rheological quality of the blood. We evaluated the records of 61 patients treated with ET to describe the present status of malaria treatment in Germany, Austria and Switzerland and to assess the efficacy of ET. Clinical data of 61 patients treated with ET were compared to data of 63 patients treated in 2 hospitals where ETs were generally not performed. We found that exchange transfusion is applied according to the clinician's subjective impression rather than strict guidelines. Logistic regression analysis adjusting for the differences in clinical parameters between patients treated with or without ET did not identify treatment as a prognostic indicator (odds ratio for relative risk of death with ET: 1.3; 95% CI: 0.4-4.9). Exchange transfusion did not significantly improve the unfavourable prognosis in cases of severe falciparum malaria. However, failure to reach statistical significance may be due to the retrospective design of the study and therefore non-systematic approach.

Acute poisoning with amphetamines (MDEA) and heroin: antagonistic effects between the two drugs.

A case of oral ingestion of large doses of both the amphetamine-derivative 3,4-methylene dioxyethamphetamine (MDEA) and heroin is reported. Despite high serum levels of both drugs, the patient did not present with the classic signs and symptoms normally seen during intoxication with these drugs. The patient recovered after symptomatic treatment. The possibility that opposite pharmacological properties of the two drugs prevented the patients death is discussed.

Combined type B aortic dissection and fusiform abdominal aortic aneurysm. Case reports.

Two patients are described with a combined type B aortic dissection and a fusiform abdominal aortic aneurysm, the dissection not involving the aneurysm. In a seventy-year-old man a type B aortic dissection and a large abdominal aneurysm were found. An infrarenal aortic bifurcation graft was inserted. He died fifteen months later of cardiogenic shock. In a sixty-six-year-old man diagnosis of a primary aortoduodenal fistula was made together with a limited type B dissection. A straight aortic interposition graft was inserted. He died eleven months later of the complications of a secondary aortoduodenal fistula. Although combination of aortic dissection and abdominal aneurysm is a rare occurrence, conservative management of the aortic dissection and interposition graft for the abdominal aneurysm was successful as initial treatment in these 2 patients.

Twelve patients with severe malaria treated with partial exchange transfusion. Comparison between mathematically predicted and observed effect on parasitaemia.

Imported malaria is increasing in Western countries, which results in considerable morbidity and mortality, the latter mainly due to delayed diagnosis and treatment. Partial exchange transfusion has been proposed as a therapy for very severe falciparum malaria, but the utility of this procedure has not been proven. We report on 12 patients with severe Plasmodium falciparum malaria, treated with exchange transfusion in 5 Belgian hospitals between 1987 and 1991. The mean parasitaemia before exchange was 17.2% (range 6-35%). An average of 3.1 l was exchanged within 3 to 7 hours. Ten of the 12 patients survived. One patient recovered initially, but died as a consequence of a cascade of complications of dialysis. Three patients developed the adult respiratory distress syndrome (ARDS), two had less serious pulmonary involvement, and five had temporary renal failure; none of the survivors had sequelae. A formula is proposed to calculate the expected reduction in parasitized erythrocytes by exchange transfusion in function of the initial parasitaemia, the initial haemoglobin level and the volume of blood exchanged. Comparison between the mathematically predicted and the observed decline in parasitaemia shows on average a 25% excess of observed over predicted efficacy per unit of blood exchanged. After introducing this correction the formula enables the clinician to estimate roughly the volume of blood that has to be exchanged in order to bring the initial parasitaemia down to a desired level.

Adult respiratory distress syndrome associated with Mycoplasma pneumoniae infection.

A 13-year-old boy is described who developed severe adult respiratory distress syndrome (ARDS), biochemical pancreatitis and skin vasculitis after an acute respiratory infection due to Mycoplasma pneumoniae. The boy was mechanically ventilated for 17 days, but could be discharged in good clinical condition after 36 days of hospitalization. However, major disturbances of the lung function tests persisted, suggesting interstitial fibrosis. To the best of our knowledge, this is the first case of ARDS after M. pneumoniae infection in childhood.

Haemodynamic monitoring. Problems, pitfalls and practical solutions.

The synthesis of adenosine triphosphate (ATP) depends on the coordinated interaction of oxygen delivery and glucose breakdown in the Krebs cycle. Cellular oxygen depots are non-existent, therefore the peripheral cells are totally dependent on the circulation for sufficient oxygen delivery. Shock is the clinical manifestation of cellular oxygen craving. The commonly measured variables--blood pressure, heart rate, urinary output, cardiac output and systemic vascular resistance--are not sensitive or accurate enough to warn of impending death in acutely ill patients nor are they appropriate for monitoring therapy. Calculated oxygen transport and oxygen consumption parameters provide the best available measures of functional adequacy of both circulation and metabolism. In order to optimise oxygen delivery (DO2), 4 interacting factors must be taken into account: cardiac output, blood haemoglobin content, haemoglobin oxygen saturation and avidity of oxygen binding to haemoglobin. For viscosity reasons, the optimal haemoglobin concentration is in the vicinity of 90 to 100 g/L, but for optimising the oxygen transport 100 to 115 g/L or a haematocrit of 30 to 35% seems better. The p50 (the pO2 at which haemoglobin is 50% saturated) describes the oxygen-haemoglobin dissociation curve; normally its value is +/- 27 mm Hg. It can be influenced by attaining normal body temperature, pH, pCO2 and serum phosphorous levels. In order to obtain an arterial blood saturation (SaO2) of more than 90% with acceptable haemodynamics, the ventilation mode and inspired oxygen fraction (FiO2) must be adapted; care must be taken not to stress the labile circulation with haemodynamic compromising ventilation techniques [e.g. high positive end expiratory pressure (PEEP) levels, inverse-ratio ventilation, etc.]. The factor most amenable to manipulation is the cardiac output, with its 4 determinants--preload, afterload, contractility and heart rate. In daily clinical practice, heart rate should be between 80 and 120 beats/min; small variations are acceptable. Important deviations must be treated by chemically [isoprenaline (isoproterenol)] or electrically (pacing techniques) accelerating the heart, or with the different antiarrhythmic drugs. A wide variety of agents is available to decrease the preload: diuretics [especially furosemide (frusemide)], venodilators like nitroglycerin (glyceryl trinitrate), isosorbide dinitrate (sorbide nitrate) and sodium nitroprusside, ACE inhibitors, phlebotomy, and haemofiltration techniques (peritoneal or haemodialysis, continuous arteriovenous haemofiltration). To increase the preload, volume loading using a rigid protocol ('rule of 7 and 3'), preferably with colloids, or vasopressor agents [norepinephrine (noradrenaline), epinephrine (adrenaline), dopamine] are useful. Arterial vasopressors are needed to improve perfusion pressure of 'critical' (coronary and cerebral) arteries. Afterload can be decreased by arterial vasodilators. Predominantly arterial dilators are hydralazine and clonidine, while sodium nitroprusside, nitroglycerin and isosorbide dinitrate have combined arterial and venous dilating actions.(ABSTRACT TRUNCATED AT 400 WORDS)

Pneumoperitoneum--a rare complication of cardiopulmonary resuscitation.

Pneumoperitoneum following cardiopulmonary resuscitation (CPR) results from a thoracic air leak (pneumothorax, pneumomediastinum) with escape of the air through diaphragmatic apertures (mostly foramen of Winslow) or primary perforation of the gastrointestinal tract (stomach or esophagus). We report three cases of pneumoperitoneum complicating CPR. As there was no clinical evidence of peritonitis, and the patients remained stable, a conservative approach was followed without surgical exploration. All patients recovered completely.