Necrotizing fasciitis in haematological patients: a different scenario.

To describe and compare the characteristics of necrotizing fasciitis (NF) in patients with and without haematological malignancy. All adult patients diagnosed with NF and treated at our hospital were included (January 2010-March 2019). Diagnosis was based on intraoperative findings or consistent clinical/radiological characteristics, and patients were classified as group A (with haematological malignancy) or group B (without haematological malignancy). Student's t (quantitative), Fisher's exact (qualitative), and Kaplan-Meyer tests were used for the statistical analysis. The study included 29 patients: 8 in group A and 21 in group B. All haematological patients had severe neutropenia (0.2 [0.02-0.5] ×109 cells/L; p < 0.001) and positive blood cultures (100% vs. 61.9%; p = 0.04) at diagnosis. Gram-negative bacilli NF was more common in group A (87.5% vs. 9.5%; p = 0.001), predominantly due to Escherichia coli (50% vs. 9.5%; p = 0.056). Surgical treatment was less common in haematological patients (5 [62.5%] vs. 21 [100%]; p = 0.015). Overall, 9 (31%) patients died: 4 (50%) in group A and 5 (23.8%) in group B (p = 0.17). The univariate analysis showed that mortality tended to be higher (OR 3.2; 95%CI 0.57-17.7; p = 0.17) and to occur earlier (2.2 ± 2.6 vs. 14.2 ± 19.9 days; p = 0.13) in haematological patients. The LRINEC index > 6 did not predict mortality in either group. In our study, NF in patients with haematological malignancies was mainly due to Gram-negative bacilli, associated to high and early mortality rates. In our experience, the LRINEC scale was not useful for predicting mortality.

"Reverse" hip spacer for massive distal femur defects in peri-prosthetic knee infections. / Espaciador de cadera «invertido¼ para defectos masivos de fémur distal en infecciones periprotésicas de rodilla.

BACKGROUND: Bone loss in the distal femur is a common problem in knee revision surgeries. The problem is exacerbated in the context of an active infection. In extreme cases this bone loss could compromise the feasibility of a two-stage exchange protocol using dynamic spacers due to the inherent instability of this type of spacers. Use of a hip prefabricated spacer in a "reverse" way forming a ball-and- socket joint is a therapeutic option in cases of massive bone defect and infection. MATERIAL AND METHODS: A retrospective review was performed of our institutional database to identify all cases of massive distal femoral defect in which this technique was used from January 2010 to December 2013. A record was made of the epidemiological data, characteristics of the infection (clinical and microbiological), and adverse event during the spacer stage. The main end-point was the infection eradication rate (minimum: 18 months of follow-up). The complications associated with the technique were also assessed. Finally, each patient completed a visual analogue pain scale, and a satisfaction questionnaire (SAPS). RESULTS: This technique was successfully used in six cases so far, controlling the infection in all cases. Mean femoral defect was 117cm (range: 32-191cm). Mean time with spacer was 7.6 months, with no major complications. All but one patient reached second stage reconstruction with a mega-prosthesis, and mean time since second stage was 34.7 months. All patients stated high levels of satisfaction with the technique employed, as well as and low pain scores (mean visual analogue pain scale: 1; range: 0-4). CONCLUSION: A reproducible and safe technique is described. Patients report a high level of satisfaction with the procedure, and there were no cases of recurrence of the infection after a minimum follow-up of 18 months.

A combined in silico/in vitro approach unveils common molecular requirements for efficient BVDV RdRp binding of linear aromatic N-polycyclic systems.

In this work, we present and discuss a comprehensive set of both newly and previously synthesized compounds belonging to 5 distinct molecular classes of linear aromatic N-polycyclic systems that efficiently inhibits bovine viral diarrhea virus (BVDV) infection. A coupled in silico/in vitro investigation was employed to formulate a molecular rationale explaining the notable affinity of all molecules to BVDV RNA dependent RNA polymerase (RdRp) NS5B. We initially developed a three-dimensional common-feature pharmacophore model according to which two hydrogen bond acceptors and one hydrophobic aromatic feature are shared by all molecular series in binding the viral polymerase. The pharmacophoric information was used to retrieve a putative binding site on the surface of the BVDV RdRp and to guide compound docking within the protein binding site. The affinity of all compounds towards the enzyme was scored via molecular dynamics-based simulations, showing high correlation with in vitro EC50 data. The determination of the interaction spectra of the protein residues involved in inhibitor binding highlighted amino acids R295 and Y674 as the two fundamental H-bond donors, while two hydrophobic cavities HC1 (residues A221, I261, I287, and Y289) and HC2 (residues V216, Y303, V306, K307, P408, and A412) fulfill the third pharmacophoric requirement. Three RdRp (K263, R295 and Y674) residues critical for drug binding were selected and mutagenized, both in silico and in vitro, into alanine, and the affinity of a set of selected compounds towards the mutant RdRp isoforms was determined accordingly. The agreement between predicted and experimental data confirmed the proposed common molecular rationale shared by molecules characterized by different chemical scaffolds in binding to the BVDV RdRp, ultimately yielding compound 6b (EC50 = 0.3 µM; IC50 = 0.48 µM) as a new, potent inhibitor of this Pestivirus.

Benzotriazole: An overview on its versatile biological behavior.

Discovered in late 1960, azoles are heterocyclic compounds class which constitute the largest group of available antifungal drugs. Particularly, the imidazole ring is the chemical component that confers activity to azoles. Triazoles are obtained by a slight modification of this ring and similar or improved activities as well as less adverse effects are reported for triazole derivatives. Consequently, it is not surprising that benzimidazole/benzotriazole derivatives have been found to be biologically active. Since benzimidazole has been widely investigated, this review is focused on defining the place of benzotriazole derivatives in biomedical research, highlighting their versatile biological properties, the mode of action and Structure Activity Relationship (SAR) studies for a variety of antimicrobial, antiparasitic, and even antitumor, choleretic, cholesterol-lowering agents.

Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study.

We aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement>30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68-81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13-0.40; p<0.001), whereas chronic renal impairment predicted failure (aHR, 2.56; 95% CI, 1.14-5.77; p 0.0232). Our results confirm a 79% success rate in ciprofloxacin-susceptible GN-PJI treated with debridement, ciprofloxacin and implant retention. New therapeutic strategies are needed for ciprofloxacin-resistant PJI.

Temporary cement tectoplasty: a technique to improve prefabricated hip spacer stability in two-stage surgery for infected hip arthroplasty.

This technical note describes an intraoperatively custom-made, antibiotic-loaded bone cement roof, used in conjunction with a prefabricated hip spacer to improve component stability, as part of the first stage of a two-stage procedure for an infected hip implant. This technique was successfully used in seven cases who presented with extensive superior and/or posterio-superior acetabular defect, which created a risk of spacer dislocation. With this technique we were able to avoid any further dislocation in these seven cases. We believe that the technique may reduce postoperative spacer dislocation in cases with extensive acetabular defects, while improving clinical outcomes.

Quinoxaline 1,4-dioxide: a versatile scaffold endowed with manifold activities.

Since 1940s, Quinoxaline 1,4-dioxides (QdNO's) are known as potent antibacterial agents, and subtherapeutic levels have been used to promote growth and improve efficiency of feed conversion in animal feed. They have also shown a selective cytotoxicity against hypoxic cells present in solid tumours. Furthermore, recent studies have put in evidence that QdNO's are endowed with antitubercular, antiprotozoal and anticandida activities. On the other hand, several authors have reported about photoallergic and mutagenic effects of some derivatives. QdNO's may also cause the development of antibiotic-resistant bacteria and influence the horizontal transfer of virulence genes between bacteria. In this review article we report the biological properties, the mode of action and Structure Activity Relationship (SAR) studies of the QdNO derivatives. Furthermore, some cytogenetic and genotoxic effects, classical and more recent method of synthesis, the quinoxaline 1,4-dioxides, and some of their most important reactions, were also reported.

Novel heteroplasmic mtDNA mutation in a family with heterogeneous clinical presentations.

The protean manifestations of a novel maternally inherited point mutation of the mitochondrial genome are reported. The proband showed isolated, spastic paraparesis. A brother, who had suffered from a multisystem progressive disorder, ultimately died of cardiomyopathy. Another brother is healthy. The proband's mother showed truncal ataxia, dysarthria, severe hearing loss, mental regression, ptosis, ophthalmoparesis, distal cyclones, and diabetes mellitus. A muscle biopsy performed in the proband failed to show the morphological abnormalities typical of mitochondrial disorders; the activities of respiratory chain complexes were normal. However, complex I and IV activities were low in the muscle homogenate of the affected mother and brother. Sequence analysis of mtDNA showed a heteroplasmic mutation of the tRNA(Ile) gene (G4284A). The mutation load was approximately 55%, 80%, and 90% in the muscle mtDNA of the proband, his mother, and his affected brother, respectively. Mutation was undetected in the healthy brother, as well as in 100 control samples. Several cybrid clones containing homoplasmic mutant mtDNA from the proband showed significant reductions of complex IV activity and maximum oxygen consumption rate, compared with homoplasmic wild-type clones derived from the same subject.

A novel mtDNA mutation in the ND5 subunit of complex I in two MELAS patients.

We identified a novel heteroplasmic mutation in the mitochodrial DNA gene encoding the ND5 subunit of complex I. This mutation (13514A-->G) hits the same codon affected by a previously reported mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS)-associated mutation (13513G-->A), but the amino acid replacement is different (D393G vs D393N). The 13514A-->G mutation was found in two unrelated MELAS-like patients. However, in contrast to typical MELAS, lactic acidosis was absent or mild and the muscle biopsy was morphologically normal. Strongly positive correlation between the percentage of heteroplasmy and defective activity of complex I was found in cybrids. We found an additional 13513G-->A-positive case, affected by a progressive mitochondrial encephalomyopathy. Our results clearly demonstrate that the amino acid position D393 is crucial for the function of complex I. Search for D393 mutations should be part of the routine screening for mitochondrial disorders.

A novel frameshift mutation of the mtDNA COIII gene leads to impaired assembly of cytochrome c oxidase in a patient affected by Leigh-like syndrome.

We report on a novel frameshift mutation in the mtDNA gene encoding cytochrome c oxidase (COX) subunit III. The proband is an 11-year-old girl with a negative family history and an apparently healthy younger brother. Since 4 years of age, she has developed a progressive spastic paraparesis associated with ophthalmoparesis and moderate mental retardation. The presence of severe lactic acidosis and Leigh-like lesions of putamina prompted us to perform muscle and skin biopsies. In both, a profound, isolated defect of COX was found by histochemical and biochemical assays. Sequence analysis of muscle mtDNA resulted in the identification of a virtually homoplasmic frameshift mutation in the COIII gene, due to the insertion of an extra C at nucleotide position 9537 of mtDNA. Although the 9537C(ins) does not impair transcription of COIII, no full-length COX III protein was detected in mtDNA translation assays in vivo. Western blot analysis of two-dimensional blue-native electrophoresis showed a reduction of specific crossreacting material and the accumulation of early-assembly intermediates of COX, whereas the fully assembled complex was absent. One of these intermediates had an electrophoretic mobility different from those seen in controls, suggesting the presence of a qualitative abnormality of COX assembly. Immunostaining with specific antibodies failed to detect the presence of several smaller subunits in the complex lacking COX III, in spite of the demonstration that these subunits were present in the crude mitochondrial fraction of patient's cultured fibroblasts. Taken together, the data indicate a role for COX III in the incorporation and maintenance of smaller COX subunits within the complex.

Quinoxaline chemistry. Part 13: 3-Carboxy-2-benzylamino-substituted quinoxalines and N-[4-[(3-carboxyquinoxalin-2-yl) aminomethyl]benzoyl]-L-glutamates: synthesis and evaluation of in vitro anticancer activity.

Among a new series of 28 3-carboxy or carbethoxy quinoxalines bearing a substituted benzylamino or N-[4-(aminomethyl)benzoyl]glutamate group on position 2 of the ring and various substituents at C-6, 7 positions, 21 were selected at the National Cancer Institute for evaluation of their in vitro anticancer activity. The results obtained seem to confirm that the carboxy or carbethoxy group on position 3 is not helpful, with a few exceptions, for the anticancer activity.

Nuclear gene defects in mitochondrial disorders.

An increasing number of nuclear genes have been associated with abnormalities of oxidative phosphorylation and mitochondrial disorders. The protein products of these genes can be grouped into three categories: structural components of the respiratory chain, factors influencing the structural integrity or the copy number of mitochondrial DNA, and proteins which control the formation, assembly and turnover of the respiratory complexes. Loss-of-function mutations in SURF-1, a gene belonging to the third category, have been associated with Leigh syndrome with cytochrome c oxidase deficiency. Mature Surf-1 protein (Surf-1p) is a 30 kDa hydrophobic polypeptide whose function is still unknown. Using antibodies against human Surf-1p, we demonstrated that this protein is imported into mitochondria as a larger precursor. The same analysis revealed that no protein is present in cell lines harboring loss-of-function mutations of SURF-1, regardless of their type and position. We also generated several constructs with truncated or partially deleted SURF-1 cDNAs. None of these constructs, expressed into SURF-1 null mutant cells, were able to rescue the COX phenotype, suggesting that different regions of the protein are all essential for function. Finally, experiments based on 2D gel electrophoresis indicated that assembly of COX in SURF-1 null mutants is blocked at an early step, most likely before the incorporation of subunit II in the nascent intermediates composed of subunit I alone or subunit I plus subunit IV.

Quinoxaline chemistry. Part 11. 3-Phenyl-2[phenoxy- and phenoxymethyl]-6(7) or 6,8-substituted quinoxalines and N-[4-(6(7)-substituted or 6,8-disubstituted-3-phenylquinoxalin-2-yl)hydroxy or hydroxymethyl] benzoylglutamates. Synthesis and evaluation of in vitro anticancer activity and enzymatic inhibitory activity against dihydrofolate reductase and thymidylate synthase.

Twenty-four out of twenty-nine quinoxalines were selected at the National Cancer Institute, Bethesda, Md, USA, for in vitro anticancer screening. Among these, 10 derivatives exhibited high values of percent tumor growth inhibition at a concentration of 10(-4) M in all cancer cell lines. Four of these compounds maintained these values at 10(-5) M, whereas a certain number exhibited significant values of percent inhibition at the most diluted concentrations (10(-8)-10(-6) M). Inhibitory activity against dihydrofolate reductase (DHFR) (bovine and rat liver) was determined for the most active compounds. This test showed that this type of quinoxaline exhibited an appreciable activity in comparison with the previously described aza analogues. In the other test (Lactobacillus casei, thymidylate synthase (TS), human HTS) no or poor activity was detected in both series of compounds.

Quinoxaline chemistry. Part 10. Quinoxaline 10-oxa-analogues of trimetrexate (TMQ) and of 5,8-dideazafolic acid. Synthesis and evaluation of in vitro anticancer activity.

Among twenty-eight novel compounds (twenty-two 2,3-disubstituted-6-[(substituted-phenoxy)methyl-quinoxalines and six 4-[(2,3-disubstituted-quinoxalin-6-yl)methoxy]benzoylglutamates ) only thirteen were selected at NCI for evaluation of their in vitro anticancer activity. The results have shown that compounds 3l,c,b,e and 4b were endowed with significantly high values of percent tumor growth inhibition on several tumor cell lines at 10(-4) M, while compound 3t was characterized by a high selectivity, being still strongly inhibiting on three cell lines at 10(-5) M. Comparison of the presently observed activity with that of the previously described aza-analogues confirms that the effected isosteric substitution is highly valuable in some cases.

Quinoxaline chemistry. Part 12. 3-Carboxy-2[phenoxy]-6(7)substituted quinoxalines and N-[4-(6(7) substituted-3-carboxyquinoxalin-2-yl)hydroxy] benzoylglutamates. Synthesis and evaluation of in vitro anticancer activity.

Thirty quinoxalines bearing a substituted phenoxy or hydroxybenzoylglutamate group on position 2, a carboethoxy or carboxy group on position 3 and a trifluoromethyl group on position 6 or 7 of the heterocycle were prepared in order to evaluate the in vitro anticancer activity. Screening over 21 compounds selected at the National Cancer Institute (Bethesda, MD) showed that only few derivatives exhibited a moderate growth inhibition activity on various tumor panel cell lines at 10(-4) molar concentration. The acid derivatives showed no growth inhibition activity. The results obtained in this series seem to indicate that in general carboxy or carboethoxy groups close to O-link with phenyl or benzoyl glutamates on position 2 are detrimental for anticancer activity.

Laminin-alpha2 but not -alpha1-mediated adhesion of human (Duchenne) and murine (mdx) dystrophic myotubes is seriously defective.

It has been suggested that alpha-dystroglycan links the dystrophin-associated protein complex and extracellular matrix and that the absence of dystrophin and alpha-dystroglycan in Duchenne muscular dystrophy (DMD) may lead to the breakdown of this linkage. In the present study, myotubes from DMD patients and murine X-linked muscular dystrophic mice (mdx) were used to measure their adhesive force to the physiological laminin-alpha2 substrate, and it was found that the dystrophic myotubes were selectively unable to sustain adhesion. However, normal and dystrophic myotubes attached equally well to the laminin-alpha1 substrate. As far as we know, this is the first experimental evidence that the absence of dystrophin causes the complete loss of a still unknown laminin-alpha2-dependent adhesion force, therefore suggesting that the primary consequence of Duchenne dystrophy consists of the loss of an authentic mechanical linkage at the level of the alpha-dystroglycan/basal lamina interface.

[Return to work following myocardial infarction. Medical and socio-professional factors]. / Reprise du travail après infarctus du myocarde. Facteurs médicaux et socioprofessionnels.

The aim of this study was to assess the influence of medical and socioprofessional factors on return to work after myocardial infarction. The authors studied a continuous series of 174 patients with an average age of 51.3 years, all of whom were active before their illness. The average follow-up period was 33 months. One hundred and thirty of the patients (75%) returned to work. The only clinical factors predictive of not returning to work were older age short exercise time and fall in blood pressure on exercise. On the other hand, nearly all socioprofessional factors, social class, type of occupation, size of company, length of employment in their company, physical stresses related to their occupation, were related to return to work. The average time before returning to work was 5.5 +/- 1 month. Though certain immediate criteria of severity of infarction such as previous myocardial infarction or anterior wall infarction were related to a more delayed return to work. The cardiac status evaluated by complementary investigations (left ventricular ejection fraction, exercise testing and Holter monitoring) was not related to the time before return to work. Of the socioprofessional factors, only difficulties related to the patients' work (modification or change of job) were associated with a more delayed return to work. Forty-four patients (33.8%) returned to work after a change in working hours (28 patients), the tasks involved (20 patients) or position (7 patients). Only the lower socioprofessional classes, independent workers and extremes of age could benefit from these measures.

[Detection and prognostic value of silent myocardial ischemia]. / Détection et valeur pronostique de l'ischémie myocardique silencieuse.

Silent myocardial ischaemia (SMI) is a common manifestation of coronary artery disease. Continuous electrocardiographic recordings have shown that 75% of ischemic episodes are asymptomatic. In addition, SMI has the same consequences as symptomatic ischaemia on myocardial perfusion and ventricular function. There are many means of detecting SMI, continuous electrocardiographic monitoring, exercise stress testing with or without methods of analysis of myocardial perfusion or wall motion using radioactive tracers or echocardiography. The latter techniques seem to improve the sensitivity of exercise stress testing. More recently, pharmacological stress testing coupled with myocardial scintigraphy or echocardiography has been introduced. In coronary patients, the prevalence of SMI on Holter monitoring is about 50% in angina and 25% after myocardial infarction. The prognostic value of SMI has been the object of much research. In asymptomatic patients with documented coronary artery disease, SMI is associated with a relative risk of a cardiac event 2 to 3 times greater than that of subjects without ischaemia. In angina pectoris, the relative risk of future cardiac events is 5.3 times greater, and that of death is 2.3 times greater. These results reported with the Holter method have been confirmed by those of exercise stress testing with and without coupled imaging techniques. In unstable angina, the results are the same: the relative risk of cardiac events in patients with SMI on Holter monitoring is increased by a factor of 4.5, and that of death by a factor of 4. This increased risk is also observed after myocardial infarction whether SMI is recorded by Holter monitoring or exercise stress testing. However, these observations are not confirmed in all reports.(ABSTRACT TRUNCATED AT 250 WORDS)

Dexamethasone isonicotinate inhibits dual and late asthmatic reactions but not the increase of airway responsiveness induced by toluene diisocyanate in sensitized subjects.

To determine whether treatment with aerosolized dexamethasone isonicotinate inhibits asthmatic reactions and the associated increase in airway responsiveness induced by toluene diisocyanate (TDI), we studied six sensitized subjects with previously demonstrated dual or late asthmatic reaction after inhalation challenge with TDI. Dexamethasone isonicotinate (four puffs bid for seven days, ie, 0.5 mg bid for seven days; last four puffs 30 minutes before TDI) was administered for seven days before the inhalation challenge with TDI (0.010 to 0.015 ppm for 10 to 30 minutes) to each subject, according to a single-blind study design. When the subjects received no treatment, FEV1 markedly decreased and airway responsiveness increased after exposure to TDI. By contrast, when the subjects were treated with dexamethasone-isonicotinate, FEV1 decreased significantly less, but airway responsiveness still significantly increased after exposure to TDI. These results suggest that aerosolized dexamethasone isonicotinate may be used in the prophylaxis of TDI-induced late asthmatic reactions.