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Biomedical subjects

P G Jorens

Publications and source records attributed to P G Jorens.

At least 19 recordsLinked to original sources

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.

Adult↗

Post-traumatic severe fat embolism syndrome with uncommon CT findings.

Although the diagnosis of fat embolism syndrome is usually based on clinical findings, we describe ill-defined centrilobular and subpleural nodules in addition to ground-glass opacities and consolidation on a computed tomography scan of the chest in a trauma patient with fat embolism syndrome. The nodules presumably represent alveolar oedema, microhaemorrhage and an inflammatory response secondary to ischaemia and cytotoxic emboli in fat embolism syndrome. The literature of computed tomography findings in patients with fat embolism syndrome is reviewed and summarized.

Accidents, Traffic↗

Messenger RNA electroporation is highly efficient in mouse embryonic stem cells: successful FLPe- and Cre-mediated recombination.

Development of efficient short-term gene transfer technologies for embryonic stem (ES) cells is urgently needed for various existing and new ES cell-based research strategies. In this study, we present a highly efficient, nonviral non-DNA technology for genetic loading of mouse ES cells based on electroporation of defined mRNA. Here, we show that mouse ES cells can be efficiently loaded with mRNA encoding a green fluorescent reporter protein, resulting in a level of at least 90% of transgene expression without loss of cell viability and phenotype. To show that transgenes, introduced by mRNA electroporation, exert a specific cellular function in transfected cells, we electroporated stably transfected ES cell lines with mRNA encoding FLPe or Cre recombinase proteins in order to excise an FRT- or LoxP-flanked reporter gene. The results, as determined by the disappearance and/or appearance of a fluorescent reporter gene expression, show that FLPe and Cre recombinase proteins, introduced by mRNA electroporation, efficiently exert their function without influence on further culture of undifferentiated ES cell populations and their ability to differentiate towards a specific lineage.

Animals↗

Inadvertent intrathecal use of ionic contrast agent.

Intrathecal administration of ionic contrast media may cause severe and fatal neurotoxic reactions due to their hyperosmolarity and ionic nature. They are therefore strictly contraindicated for all radiologic applications involving the central nervous system (e.g., myelography). We present a case in which ioxitalamate was accidentally injected intrathecally. The patient recovered completely due to a combination of the different therapeutic options reported in the literature, including early mechanical ventilation and neuromuscular paralysis, aggressive control of seizures, elevation of head and trunk to prevent cephalad migration of contrast, steroids, cerebrospinal fluid drainage and lavage and prophylactic antibiotics.

Contrast Media↗

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.

Accidents, Traffic↗

Natural inhibitors of neutrophil function in acute respiratory distress syndrome.

OBJECTIVE: Neutrophils play a key role in the physiopathogenesis of acute lung injury in general and acute respiratory distress syndrome (ARDS) in particular. To identify the anti-inflammatory mediators with a protective effect on lung tissue damage in ARDS, we correlated the concentration of the Clara cell 16-kD protein (CC16; an inhibitor of neutrophil chemotaxis), angiogenin (an inhibitor of degranulation), and the total radical oxygen neutralizing activity with the amount of elastase (a marker of neutrophil activation) and with the Pao2/Fio2 ratio, which is inversely related to lung injury. SETTING: University hospital. PATIENTS: Patients with ARDS (n = 12) and patients at risk for developing ARDS (n = 14). INTERVENTIONS: Patients underwent bronchoalveolar lavage 12 hrs after diagnosis of ARDS or at-risk status. MEASUREMENTS AND MAIN RESULTS: The amount of CC16 and radical oxygen neutralizing activity was not significantly different in patients with or at risk for ARDS. In contrast, the amount (mean +/- sem) of angiogenin in the bronchoalveolar lavage of ARDS patients (45 +/- 14 ng/mL, n = 12) was increased 11-fold (p <.05) compared with patients at risk for ARDS (4 +/- 1 ng/mL, n = 14). In patients with ARDS, the amount of protein and angiogenin in bronchoalveolar lavage increased with decreasing concentration of CC16 (p <.05). In addition, CC16 correlated with the Pao2/Fio2 ratio (p <.05) and inversely with the amount of elastase (p <.05) and thus may be regarded as a reliable protective agent for lung injury. CONCLUSION: A high concentration of CC16, a natural inhibitor of neutrophil function, decreases neutrophil-mediated lung damage of patients with ARDS. Strategies to increase natural anti-inflammatory agents, and thus influence the disruption of the balance between natural inflammatory and anti-inflammatory or protective factors, could be useful to modulate the tissue destruction and the course of ARDS.

Acute Disease↗

Perforating oesophageal carcinoma presenting as necrotizing fasciitis of the neck.

A patient with a history of schizophrenia was admitted to our hospital in an already severe stage of necrotizing fasciitis of the neck, complicated with mediastinitis and gangrene. Later on, he also developed a vena cava superior syndrome and sepsis. In the few cases and small series described in the literature, necrotizing fasciitis of the neck is usually associated with surgery or trauma. Less frequently, an orodental or pharyngeal infection, often innocuous, is the underlying cause. None of these causes could be identified in our patient. Initially, on computer-assisted tomography (CT) scan, a tracheal rupture was suspected, but this diagnosis could not be confirmed on bronchoscopic examination. On gastroscopy, a stenotic oesophageal segment was discovered. Biopsy of this segment showed a poorly differentiated squamous cell carcinoma. The patient died in sepsis. Autopsy confirmed the presence of a large proximal oesophageal tumour with perforation. As far as we know, no case of a necrotizing fasciitis of the neck caused by perforation of a formerly unknown oesophageal carcinoma has been reported. Even mediastinitis, with or without gangrene, is rarely associated with oesophageal cancer, and in the few cases reported it is always due to fistulization after surgery.

Adult↗

Surprising findings following a Belgian food contamination with polychlorobiphenyls and dioxins.

We found that 12.1% of Belgian export meat samples from chicken or pork, unrelated to the PCB/dioxin crisis from 1999, contained more than 50 ng polychlorinated biphenyls (PCBs)/g fat and that 6.5% of samples contain more than 20 ng/g fat for the sum of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites. Part of this background contamination stems from imported animal feed ingredients (fish flour and grains), sometimes contaminated by recent use of DDT, as can be deduced from the ratio between DDT and its main metabolite, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE). However, after comparing PCB concentrations in fish flour and grains with those found in meat, we suggest that the high concentrations stem from recycled fat. This is the first paper describing background concentrations of PCBs in animal meat from Belgium.

Animal Feed↗

Encephalomyelitis-associated antimyelin autoreactivity induced by streptococcal exotoxins.

OBJECTIVE: After implicating Streptococcus pyogenes as causing acute disseminated encephalomyelitis (ADEM) in a child, we wanted to prove that in vivo activation of autoreactive T lymphocytes by superantigens of this Streptococcus contributed to the dramatic demyelination. BACKGROUND: ADEM is a demyelinating disorder of the CNS sharing many similarities with MS. Demyelination in MS is considered to be the result of an autoimmune process mediated by autoreactive T lymphocytes with specificity for myelin antigens. METHODS: Phenotypic analysis and proliferation assays on blood monocytes, as well as isolation of myelin basic protein (MBP)-reactive T-cell lines/clones; and TCR repertorium analysis by PCR-ELISA and cytokine production. RESULTS: 1) The blood T-cell receptor (TCR) repertoire was compatible with in vivo expansion induced by S. pyogenes exotoxins. 2) TCR expression analysis indicated clonal expansion of CD8+ MBP-reactive T cells, suggesting in vivo activation. MBP-reactive T cells showed crossreactivity to S. pyogenes supernatant and exotoxins. 3) Cytokine mRNA quantification of the mononuclear cells revealed a Th2-biased profile. CONCLUSION: In vivo exposure to S. pyogenes may have induced activation of pathogenic myelin reactive T cells, contributing to the dramatic inflammatory demyelination.

Autoimmunity↗

Successful recovery after ventricular fibrillation in a patient with Kawasaki disease.

Kawasaki disease (KD) is an uncommon cause of sudden death in young adults in Europe. Angiographically, the disease is characterized by coronary artery aneurysms which can be fully obstructed by acute thrombosis or by progression of the disease. If diagnosis of KD is made, immediate investigation should be made to determine whether ischemia is occurring and if so, to establish optimal time for revascularisation or cardiac transplantation. We describe an 18-year-old Caucasian male who was not previously known to have KD and who suffered from an acute myocardial infarction complicated by ventricular fibrillation, caused by acute thrombosis of a coronary artery aneurysm.

Adolescent↗

Reperfusion injury after focal myocardial ischaemia: polymorphonuclear leukocyte activation and its clinical implications.

The only way to rescue ischaemic tissue is to re-instate the oxygen supply to the tissue. However reperfusion of the ischaemic area not only oxygenates the tissue but also initiates a cascade of processes, which may in some cases result in temporary dysfunction of the myocardium. In order to devise protective measures, it is essential to understand the mechanisms and the triggers of this reperfusion phenomenon. In this review we will mainly focus on the inflammatory response caused by reperfusion. We will cover the different steps of polymorphonuclear leukocyte activation and will briefly discuss the molecular biology of the receptors involved. The currently used pharmacological medications in acute cardiology will be reviewed and in particular their actions on polymorphonuclear leukocyte activation, adhesion and degranulation. This review is a compilation of the current knowledge in the field and the therapeutic progress in the prevention of reperfusion injury made today.

Adenosine↗

Oxidatively modified proteins in bronchoalveolar lavage fluid of patients with ARDS and patients at-risk for ARDS.

Oxidative stress in acute respiratory distress syndrome (ARDS) is considered as an important pathophysiological mechanism in acute impairment of lung function. The present study investigated whether a pulmonary oxidant-antioxidant imbalance is indicated by substantial oxidative modification of proteins in bronchoalveolar lavage (BAL) fluid. Oxidatively modified proteins in BAL fluid, as measured by the reduction of protein carbonyl groups with tritiated borohydride, were studied in control subjects, patients with clinically established ARDS, and patients considered at-risk for ARDS because they had had coronary bypass surgery. Subsets of these at-risk patients were pretreated either with methylprednisolone or N-acetylcysteine. The carbonyl content of BAL fluid proteins was greatly increased in ARDS patients (5.0+/-13 nmol carbonyl x mL(-1) BAL fluid; mean+/-SEM; p=0.0004; n=10) and moderately increased in the untreated patients at-risk for ARDS (1.3+/-0.2 nmol x mL(-1); p=0.027; n=19) compared with controls (0.8+/-0.2 nmol x mL(-1); n=12). The two other at-risk groups pretreated either with methylprednisolone or N-acetylcysteine showed carbonyl values that were statistically not different from the controls (1.2+/-0.2 nmol x mL(-1); p=0.13; n=13, and 1.1+/-0.3 nmol x mL(-1); p=0.40; n=8, respectively). These results show that oxidatively modified proteins clearly accumulated in bronchoalveolar lavage fluid of acute respiratory distress syndrome patients, and to a minor extent in untreated at-risk patients. These data suggest a severe oxidant-antioxidant imbalance in acute respiratory distress syndrome.

Acetylcysteine↗

Traumatic basilar artery dissection in a child: need for anticoagulation?

Dissection of a cerebral blood vessel is a rare complication of acute neurotrauma with a high incidence of morbidity and mortality. We report on a case of a pediatric patient with severe neurological symptoms in whom angiography showed evidence of a basilar artery dissection. The patient was heparinized and recovered uneventfully.

Basilar Artery↗

Decreased release of nitric oxide (NO) by alveolar macrophages after in vivo loading of rats with either iron or ethanol.

Alveolar macrophages were isolated by pulmonary lavage from rats which had been either chronically overloaded with iron by intraperitoneal injections of iron dextran for four weeks, or rendered alcoholic by administration of increasing concentrations of alcohol vapour, also for four weeks. Although the hepatic iron content increased in both groups of animals, only the macrophages isolated from the iron-loaded animals showed a significant increase in iron content (P = < 0.05). Furthermore, in these macrophages there was a significant increase in oxidative tone as demonstrated by a six fold increase in superoxide dismutase activity. In both the iron-loaded and chronically alcoholised macrophages, there was a significant diminution in nitric oxide release after stimulation with lipopolysaccharide and/or interferon-gamma, which impaired the ability of both of these groups of macrophages to inhibit the germination of spores from the fungus Rhizopus, a nitric oxide-dependent process. Such an alteration in nitric oxide release reduces the macrophage's microbicidal activity.

Alcoholism↗

Diagnosis and nonsurgical management of bile leak complicated by biloma after blunt liver injury: report of two cases.

We report on two patients with biliary tract injury and associated biloma following blunt abdominal trauma. Both patients underwent emergency surgery because of hemodynamic instability and bloody peritoneal aspiration. Computed tomography in the postoperative days showed severe hepatic parenchymal injury and the presence of hypodense collections with intraparenchymal and subcapsular extension, suggestive for biloma, but otherwise failed to demonstrate the exact location of the bile duct injury. One of them underwent temporary percutaneous drainage. Bile duct injury was well demonstrated on endoscopic retrograde cholangiography (ERCP) and treated by endobiliary stent placement. This report advocates the use of ERCP and endobiliary stenting in the management of biliary injury resulting from liver trauma.

Abdominal Injuries↗

Localization of extracellular superoxide dismutase in rat lung: neutrophils and macrophages as carriers of the enzyme.

Immunohistochemistry (IHC) and in situ hybridization (ISH) was used to localize extracellular superoxide dismutase (EC-SOD) and its mRNA in rat lung before and after a lipopolysaccharide (LPS)- and hyperoxia-induced inflammation. In control rats, EC-SOD mRNA was synthesized in macrophages and in cells of the arterial vessel walls and the alveolar septa. The EC-SOD protein was mainly localized in plasma and on the apical side of the epithelial cells located near bronchus-associated lymphoid tissue (BALT). ISH did not reveal major changes in the distribution of EC-SOD mRNA upon induction of inflammation. In contrast, IHC demonstrated a progressive staining of the epithelium of the larger bronchi for the protein. Neutrophils and macrophages invading the lung showed an intensive staining for the EC-SOD protein concomitantly with a decrease of the enzyme in the plasma. Twenty-four hours after LPS stimulation only a spotty positivity remained on neutrophils in and between the alveolar spaces. In the bronchoalveolar lavage fluid (BALF), only macrophages showed a strong positivity for EC-SOD mRNA while the protein was detected in macrophages and neutrophils. Exposure to hyperoxia did not affect the distribution of EC-SOD mRNA and protein. The presented data demonstrated that in lung tissue the EC-SOD enzyme may have a protective function for activated macrophages, neutrophils, and lympoid tissue-associated epithelial cells.

Animals↗