Targeted modifications of neomycin and paromomycin: Towards resistance-free antibiotics?

Despite their clinical importance, saving numerous human lifes, over- and mis-uses of antibiotics have created a strong selective pressure on bacteria, which induces the emergence of (multi)resistant strains. Antibioresistance is becoming so pregnant that since 2017, WHO lists bacteria threatening most human health (AWaRe, ESKAPE lists), and those for which new antibiotics are urgently needed. Since the century turn, this context is leading to a burst in the chemical synthesis of new antibiotics, mostly derived from natural antibiotics. Among them, aminoglycosides, and especially the neomycin family, exhibit broad spectrum of activity and remain clinically useful drugs. Therefore, numerous endeavours have been undertaken to modify aminoglycosides with the aim of overcoming bacterial resistances. After having replaced antibiotic discovery into an historical perspective, briefly surveyed the aminoglycoside mode of action and the associated resistance mechanisms, this review emphasized the chemical syntheses performed on the neomycin family and the corresponding structure activity relationships in order to reveal the really efficient modifications able to convert neomycin and its analogues into future drugs. This review would help researchers to strategically design novel aminoglycoside derivatives for the development of clinically viable drug candidates.

Prevention of potentially inappropriate medication in internal medicine patients: A prospective study using the electronic application PIM-Check.

WHAT IS KNOWN: Potentially inappropriate medication (PIM) is a risk factor for drug-related problems (DRPs) and an important inpatient safety issue. PIM-Check is a screening tool designed to detect PIM in internal medicine patients. OBJECTIVE: This study aimed to determine whether PIM-Check could help to identify and reduce DRPs. METHOD: Prospective interventional study conducted on patients admitted to internal medicine wards in a university hospital between 1 September 2015 and 30 October 2015. Adult patients were included if they were hospitalized for more than 48 hours. Patients received either usual care (period 1 = control) or usual care plus medication screening by the wards' chief residents using PIM-Check (period 2 = intervention). An expert panel, composed of a clinical pharmacist, a clinical pharmacologist and two attending physicians in internal medicine, blinded to patient groups, identified DRPs. RESULTS: A total of 297 patients were included (intervention: 109). The groups' demographic parameters were similar. The expert panel identified 909 DRPs (598: control; 311: intervention). The mean number of DRPs per patient was similar in the control (3.2; 95% CI: 2.9-3.5) and intervention groups (2.9; 95% CI: 2.4-3.3) (P = .12). PIM-Check displayed 33.4% of the 311 DRPs identified in the intervention group. WHAT IS NEW AND CONCLUSION: In this study, PIM-Check had limited value, as the average number of DRPs per person was similar in both groups. Although one-third of DRPs counted in intervention group had been identified by PIM-Check, this did not lead to a reduction in DRPs. This lack of impact of PIM-Check on drug prescription may be explained by the number of alerts displayed by the application and hospital physicians' reluctance to modify the treatments for chronic conditions previously prescribed by general practitioners.

A comparison of two tools to screen potentially inappropriate medication in internal medicine patients.

WHAT IS KNOWN: Potentially inappropriate medication (PIM) is an important issue for inpatient management; it has been associated with safety problems, such as increases in adverse drugs events, and with longer hospital stays and higher healthcare costs. OBJECTIVE: To compare two PIM-screening tools-STOPP/START and PIM-Check-applied to internal medicine patients. A second objective was to compare the use of PIMs in readmitted and non-readmitted patients. METHOD: A retrospective observational study, in the general internal medicine ward of a Swiss non-university hospital. We analysed a random sample of 50 patients, hospitalized in 2013, whose readmission within 30 days of discharge had been potentially preventable, and compared them to a sample of 50 sex- and age-matched patients who were not readmitted. PIMs were screened using the STOPP/START tool, developed for geriatric patients, and the PIM-Check tool, developed for internal medicine patients. The time needed to perform each patient's analysis was measured. A clinical pharmacist counted and evaluated each PIM detected, based on its clinical relevance to the individual patient's case. The rates of screened and validated PIMs involving readmitted and non-readmitted patients were compared. RESULTS: Across the whole population, PIM-Check and STOPP/START detected 1348 and 537 PIMs, respectively, representing 13.5 and 5.4 PIMs/patient. Screening time was substantially shorter with PIM-Check than with STOPP/START (4 vs 10 minutes, respectively). The clinical pharmacist judged that 45% and 42% of the PIMs detected using PIM-Check and STOPP/START, respectively, were clinically relevant to individual patients' cases. No significant differences in the rates of detected and clinically relevant PIM were found between readmitted and non-readmitted patients. WHAT IS NEW AND CONCLUSION: Internal medicine patients are frequently prescribed PIMs. PIM-Check's PIM detection rate was three times higher than STOPP/START's, and its screening time was shorter thanks to its electronic interface. Nearly half of the PIMs detected were judged to be non-clinically relevant, however, potentially overalerting the prescriber. These tools can, nevertheless, be considered useful in daily practice. Furthermore, the relevance of any PIM detected by these tools should always be carefully evaluated within the clinical context surrounding the individual patient.

Prisoners and skin diseases in Toulouse, France: epidemiological analysis and evaluation of life impact.

BACKGROUND: Dermatology in a penitentiary environment is an under-researched field. OBJECTIVES: To study the prison population seeking medical advice for skin diseases and to assess among detainees the life impact of these diseases, an approach that to the best of our knowledge has not previously been reported. METHODS: This prospective study was carried out in the male population of two penal institutions in the region of Toulouse, south-western France. RESULTS: One hundred seventy-eight men were seen, for a total of 234 diagnoses and 281 consultations. The five most frequent diagnoses, in order of decreasing frequency, were disorders of the pilosebaceous follicle, fungal diseases, benign skin tumours, warts and eczemas, which are common skin diseases. However, 72% of inmates believed their skin disease was directly related to detention. This belief was related to the conditions of life in prison (seclusion and its effects) and to frequent psychological problems. CONCLUSIONS: The disorders observed were generally benign skin conditions that could be expected in a population of young men living in a closed community. They led to a high demand for care and treatment: skin diseases represented the largest specialist consultation in our institutions. Skin problems can easily be managed in an outpatient unit, which confirms the usefulness of a dedicated dermatology clinic within the outpatient consultation units of penal institutions in order to provide care of equivalent quality to that available in a free environment. The dermatologist can have an important role in the medical management and the health education of prisoners.

The coat protein of the yeast double-stranded RNA virus L-A attaches covalently to the cap structure of eukaryotic mRNA.

The eukaryotic mRNA 5' cap structure m7GpppX (where X is any nucleotide) interacts with a number of cellular proteins. Several of these proteins were studied in mammalian, yeast, and drosophila cells and found to be involved in translation initiation. Here we describe a novel cap-binding protein, the coat protein of L-A, a double-stranded RNA virus that is persistently maintained in many Saccharomyces cerevisiae strains. The results also suggest that the coat protein of a related double-stranded RNA virus (L-BC) is likewise a cap-binding protein. Strikingly, in contrast to the cellular cap-binding proteins, the interaction between the L-A virus coat protein and the cap structure is through a covalent bond.

His-154 is involved in the linkage of the Saccharomyces cerevisiae L-A double-stranded RNA virus Gag protein to the cap structure of mRNAs and is essential for M1 satellite virus expression.

The coat protein (Gag) of the double-stranded RNA virus L-A was previously shown to form a covalent bond with the cap structure of eukaryotic mRNAs. Here, we identify the linkage as a phosphoroimidazole bond between the alpha phosphate of the cap structure and a nitrogen in the Gag protein His-154 imidazole side chain. Mutations of His-154 abrogate the ability of Gag to bind to the cap structure, without affecting cap recognition, in vivo virus particle formation from an L-A cDNA clone, or in vitro specific binding and replication of plus-stranded single-stranded RNA. However, genetic analyses demonstrate that His-154 is essential for M1 satellite virus expression.

TIF4631 and TIF4632: two yeast genes encoding the high-molecular-weight subunits of the cap-binding protein complex (eukaryotic initiation factor 4F) contain an RNA recognition motif-like sequence and carry out an essential function.

The 5' ends of eukaryotic mRNAs are blocked by a cap structure, m7GpppX (where X is any nucleotide). The interaction of the cap structure with a cap-binding protein complex is required for efficient ribosome binding to the mRNA. In Saccharomyces cerevisiae, the cap-binding protein complex is a heterodimer composed of two subunits with molecular masses of 24 (eIF-4E, CDC33) and 150 (p150) kDa. p150 is presumed to be the yeast homolog of the p220 component of mammalian eIF-4F. In this report, we describe the isolation of yeast gene TIF4631, which encodes p150, and a closely related gene, TIF4632. TIF4631 and TIF4632 are 53% identical overall and 80% identical over a 320-amino-acid stretch in their carboxy-terminal halves. Both proteins contain sequences resembling the RNA recognition motif and auxiliary domains that are characteristic of a large family of RNA-binding proteins. tif4631-disrupted strains exhibited a slow-growth, cold-sensitive phenotype, while disruption of TIF4632 failed to show any phenotype under the conditions assayed. Double gene disruption engendered lethality, suggesting that the two genes are functionally homologous and demonstrating that at least one of them is essential for viability. These data are consistent with a critical role for the high-molecular-weight subunit of putative yeast eIF-4F in translation. Sequence comparison of TIF4631, TIF4632, and the human eIF-4F p220 subunit revealed significant stretches of homology. We have thus cloned two yeast homologs of mammalian p220.

Decoying the cap- mRNA degradation system by a double-stranded RNA virus and poly(A)- mRNA surveillance by a yeast antiviral system.

The major coat protein of the L-A double-stranded RNA virus of Saccharomyces cerevisiae covalently binds m7 GMP from 5' capped mRNAs in vitro. We show that this cap binding also occurs in vivo and that, while this activity is required for expression of viral information (killer toxin mRNA level and toxin production) in a wild-type strain, this requirement is suppressed by deletion of SKI1/XRN1/SEP1. We propose that the virus creates decapped cellular mRNAs to decoy the 5'-->3' exoribonuclease specific for cap- RNA encoded by XRN1. The SKI2 antiviral gene represses the copy numbers of the L-A and L-BC viruses and the 20S RNA replicon, apparently by specifically blocking translation of viral RNA. We show that SKI2, SKI3, and SKI8 inhibit translation of electroporated luciferase and beta-glucuronidase mRNAs in vivo, but only if they lack the 3' poly(A) structure. Thus, L-A decoys the SKI1/XRN1/SEP1 exonuclease directed at 5' uncapped ends, but translation of the L-A poly(A)- mRNA is repressed by Ski2,3,8p. The SKI2-SKI3-SKI8 system is more effective against cap+ poly(A)- mRNA, suggesting a (nonessential) role in blocking translation of fragmented cellular mRNAs.

[Pleural effusion complicating a totally implanted venous device]. / Un épanchement pleural liquidien compliquant une chambre à cathéter implantable.

INTRODUCTION: Totally implanted venous devices (TIVD) are an essential tool for repeated intravenous treatments such as chemotherapy for cancer and antibiotics for cystic fibrosis. CASE REPORT: A woman of 76 years was treated for bronchiectasis, colonised by Pseudomonas aeruginosa, with courses of intravenous antibiotics. On account of poor peripheral veins a TIVD was implanted. The implantation and subsequent antibiotic injections were uncomplicated. Three years later a further course of antibiotics was prescribed. As no reflux of blood was obtained on puncturing the device the position of the catheter was checked radiologically. The patient complained of right shoulder pain following each infusion. The chest x-ray showed a pleural effusion. The sudden onset of the effusion, the absence of signs of infection and the patient's good clinical condition suggested pleural extravasation of the antibiotic infusion from the TIVD. Pleural aspiration yielded 1400 mls of watery fluid. Injection of contrast into the TIVD confirmed intra-pleural extravasation. CONCLUSION: When using a TIVD it is important to bear in mind the possibility of late pleural complications.

Relationship between the levels of cyclic cytidine 3':5'-monophosphate, cyclic guanosine 3':5'-monophosphate, and cyclic adenosine 3':5'-monophosphate in urines and leukocytes and the type of human leukemias.

Cyclic cytidine 3':5'-monophosphate (cyclic CMP), cyclic guanosine 3':5'-monophosphate (cyclic GMP), and cyclic adenosine 3':5'-monophosphate (cyclic AMP) contents of leukocytes and urines of leukemic patients have been investigated. We have studied four types of leukemia: acute myeloblastic leukemia; chronic myelocytic leukemia; acute lymphoblastic leukemia; and chronic lymphocytic leukemia. As controls, the cyclic nucleotide content of leukocytes and urines of healthy volunteers and patients with solid tumors selected for their normal hemogram has been determined. It has also been measured in phytohemagglutinin-stimulated lymphocytes. Our data show that: (a) the concentration of cyclic CMP is always lower than that of cyclic GMP or cyclic AMP; (b) in urines, the concentrations of the three nucleotides are higher in patients than in healthy volunteers, the greatest differences being observed between the cyclic CMP concentrations of acute leukemia patients and controls; and (c) in white blood cells, cyclic AMP concentration is lower in leukemic than in normal cells. The cyclic GMP concentration is the same everywhere except in monoblastic cells and leukocytes from solid tumor patients. High cyclic CMP levels are associated only with acute leukemia, whether myeloblastic, monoblastic, or lymphoblastic, a fact which suggests that cyclic CMP could be a biochemical marker of hematopoietic stem cell malignancy.

Band slippage after laparoscopic adjustable gastric banding: etiology and treatment.

BACKGROUND: Laparoscopic adjustable gastric banding is a safe and effective procedure for the management of morbid obesity. However, band slippage is a common complication with variable presentation that can be rectified by a second laparoscopic procedure. METHODS: We studied case series of 125 consecutive patients who suffered from band slippage between November 1996 and May 2001 from a group of 1,480 laparoscopic adjustable gastric banding procedures performed during this time. The decision of whether to remove or replace/reposition the band was made prior to the operation, although the specific method used when replacement or repositioning was deemed suitable was determined by the operative findings. A laparoscopic approach was used in all but three patients. RESULTS: A total of 125 patients (8.4%) suffered band slippage (posterior slippage, 82.4%; anterior slippage, 17.6%). In 70 patients (56%), the band was removed, whereas in 55 patients (44%) it was repositioned or replaced immediately. Of these 55 patients, six underwent later removal, five due to recurrent slippage and one due to erosion. Fourteen patients suffered complications, including gastric perforation (n = 8), intraoperative bleeding (n = 1), postoperative fever (n = 3), aspiration pneumonia (n = 1), upper gastrointestinal bleeding (n = 1), and pulmonary embolism (n = 1). CONCLUSION: Band slippage is not a rare complication after laparoscopic adjustable gastric banding. The decision to remove or replace the band or convert to another bariatric procedure should be made preoperatively, taking both patient preference and etiology into consideration. Short-term results indicate that band salvage is successful when the patient population is chosen correctly.

Increased incidence of chronic GvHD and CMV disease in patients with vitamin D deficiency before allogeneic stem cell transplantation.

Vitamin D has emerged as a central player in the immune system, with its deficiency being implicated in the pathogenesis of several autoimmune diseases, including chronic GvHD. This is a retrospective cohort analysis of 166 patients, who underwent allogeneic hematopoietic stem cell transplantation (HSCT) at the Karolinska University Hospital, evaluating GvHD, graft failure, infectious complications and survival after HSCT in relation to pre-transplantation vitamin D levels. Most of the patients were deficient in vitamin D before HSCT (median 42 nmol/L). In multivariate analysis, vitamin D level before HSCT was identified as a significant independent risk factor for development of cGvHD. The increased incidence of cGvHD was not coupled to better disease-free survival; instead there was a trend towards lower overall survival in the vitamin D-deficient patients. In addition, we found a significant correlation between vitamin D deficiency and incidence of CMV disease, with no case of CMV disease occurring in patients with sufficient levels of vitamin D before HSCT. Our results support a role of vitamin D in immune tolerance following HSCT. These findings could be highly relevant for the care of HSCT patients, and prospective, randomized studies on the effect of vitamin D supplementation are therefore needed.

Allogeneic or autologous bone marrow transplantation for acute lymphoblastic leukemia in first complete remission.

Forty-seven patients with high risk acute lymphoblastic leukemia (ALL) received an allogeneic (allo) or autologous (auto) bone marrow transplant (BMT). Patients in both groups were comparable in terms of age, initial presentation of ALL and induction chemotherapy. Allo patients were transplanted earlier (median 3 months after CR) than auto patients (median 6.5 months after CR). Auto patients received more consolidation chemotherapy before BMT. All patients received total body irradiation 2.2 Gy/day x 5 days after cyclophosphamide 60 mg/kg x 2 (18 allo and five auto) or melphalan 140 mg/m2 (seven allo and 17 auto). Prevention of graft-versus-host disease (GVHD) was by conventional immunosuppression in 17 patients and T cell depletion in eight. Seven patients (28%) developed moderate to severe acute GVHD. Auto marrow was treated in vitro in each case. Seven patients died in CR from BMT complications (five allo and two auto). The probability of relapse was 9% for patients receiving allo BMT and 52% for patients receiving auto BMT (p less than 0.01). The disease-free survival was 71% for allo BMT and 40% for auto BMT (p = NS). Early BMT is an effective form of consolidation for high risk patients with ALL in first CR. An allogeneic anti-leukemia effect was demonstrated in this study.

Bone marrow transplantation in 63 adult patients with acute lymphoblastic leukemia in first complete remission.

Over a 10 year period, we transplanted 63 patients with acute lymphoblastic leukaemia (ALL) who had achieved first complete remission (CR). All were > 15 years old and 45 (71%) had at least one poor prognostic factor. Twenty-nine patients with a suitable sibling underwent autologous bone marrow transplantation (BMT). Beginning in 1984, patients without a donor received an allogeneic BMT (34 patients). Preparation consisted of cyclophosphamide (CY)/TBI (78%) or melphalan (Mel)/TBI (22%); marrow was treated in vitro in 31 patients (allogeneic: 7; autologous: 24). Kaplan-Meier estimates of the probability at 6 years of relapse, survival and DFS were 41% (allogeneic: 10%, autologous: 65%, p < 0.05), 44% (allogeneic: 62%, autologous: 26%, p = NS) and 42% (allogeneic: 62%, autologous: 27%, p < 0.06), respectively. This report confirms that allogeneic BMT permits long-term remissions giving high levels of survival when performed shortly after entering first CR while autologous BMT, when performed in the same setting, is less successful at preventing relapse. This study also confirms the high sensitivity of ALL to the graft-versus-leukemia effect provided by allogeneic BMT. Chemoradiotherapy dose intensification delivered at autologous BMT is not sufficient to prevent relapses. Autologous BMT must therefore be augmented by other approaches of which immunotherapy may be one.

A novel variant of transthyretin (Glu42Asp) associated with sporadic late-onset cardiac amyloidosis.

A sixty-three year old French man presented with isolated late-onset amyloid cardiomyopathy proven by endomyocardial biopsy. There was no known family history of amyloidosis. Immunohistochemistry of cardiac deposits suggested that amyloi fibrils were derived from transthyretin. DNA sequencing revealed a point mutation in exon 2 of the transthyretin gene responsible for a novel amyloidogenic variant Asp42.

Hypoxia and angiotensin II infusion redistribute lung blood flow in lambs.

To assess the effects of alveolar hypoxia and angiotensin II infusion on distribution of blood flow to the lung we performed perfusion lung scans on anesthetized mechanically ventilated lambs. Scans were obtained by injecting 1-2 mCi of technetium-labeled albumin macroaggregates as the lambs were ventilated with air, with 10-14% O2 in N2, or with air while receiving angiotensin II intravenously. We found that both alveolar hypoxia and infusion of angiotensin II increased pulmonary vascular resistance and redistributed blood flow from the mid and lower lung regions towards the upper posterior region of the lung. We assessed the effects of angiotensin II infusion on filtration pressure in six lambs by measuring the rate of lung lymph flow and the protein concentration of samples of lung lymph. We found that angiotensin II infusion increased pulmonary arterial pressure 50%, lung lymph flow 90%, and decreased the concentration of protein in lymph relative to plasma. These results are identical to those seen when filtration pressure increases during alveolar hypoxia. We conclude that alveolar hypoxia and angiotensin II infusion both increase fluid filtration in the lung by increasing filtration pressure. The increase in filtration pressure may be the result of a redistribution of blood flow in the lung with relative overperfusion of vessels in some areas and transmission of the elevated pulmonary arterial pressure to fluid-exchanging sites in those vessels.

Influence of respiration on heart rate and blood pressure fluctuations.

The dynamics of the respiratory and cardiovascular systems were studied by continuously slowing respiration from 0.46 to 0.05 Hz. The time-frequency distribution and global spectral analysis were used to assess the R-R interval (R-R) and the systolic and diastolic blood pressure fluctuations in 16 healthy subjects. During rest, the nonrespiratory-to-respiratory frequency ratios were not affected by occasional slow breathing, whereas the low- (0.01-0.15 Hz) to high- (0.15-0.3 Hz) frequency indexes for blood pressure were increased (P < 0.05). The respiratory fluctuations in R-R and the systolic and diastolic pressures were paced over the 0.46- to 0.05-Hz range. As respiration slowed to 0.07-0.09 Hz, the frequency content of the respiration and cardiovascular variables increased sharply and nonlinearly to a maximum that exceeded values at higher frequencies (P < 0.001). The nonrespiratory frequency content remained stable in the 0.01- to 0.05-Hz range and did not significantly differ from that at rest. In contrast, the nonstable 0.05- to 0.1-Hz component was suppressed. A slow 0.012- to 0.017-Hz rhythm modulated respiration and hemodynamic fluctuations at both respiratory and nonrespiratory frequencies. The study indicated that respiration input should be considered in the interpretation of global spectra. Furthermore the time-frequency distributions demonstrated that a close nonlinear coupling exists between the respiratory and cardiovascular systems.

Direct acridine orange fluorescence examination of blood slides compared to current techniques for malaria diagnosis.

The renewed interest in the use of fluorochromes for malaria diagnosis prompted us to evaluate the acridine orange fluorescence technique on blood slides, and to compare it with established techniques using thick and thin blood films and the QBC malaria test, using the Giemsa-stained thick film technique as our standard method for comparison. We compared 123 positively diagnosed cases and 120 negative cases. For primary samples (day 0), the sensitivity of the thin blood film fluorescence acridine orange technique (AO) was 96.4%, and its specificity was 95.1%. In cases of imported malaria, with a prevalence rate of 16.2%, the positive predictive value was 79.2% and the negative predictive value 99.3%. Sensitivity of AO was significantly higher than that of Giemsa-stained thin blood films for parasitaemias < 5000/microL. The potential of AO for species diagnosis of Plasmodium was 85.2%, using Giemsa-stained thin films as the reference technique. Where QBC imposes a cost limitation, especially in developing countries, despite its high performance, the AO diagnostic technique is a valuable alternative, because of its simplicity, almost negligible cost, and its diagnostic reliability. The method may also have potential value in the diagnosis of other microbiological diseases.

Malaria, cause of ahaptoglobinaemia in Africans.

The lack of serum haptoglobin in Africans has been investigated in the Congo, Central Africa, where HpO prevalence is about 30%. This study shows that it is possible to suppress ahaptoglobinaemia within a few weeks by antimalarial chemoprophylaxis, that it does not occur in protected individuals, that ahaptoglobinaemia reappears at its original incidence levels after interruption of chemoprophylaxis, and that some individuals are more susceptible in relation to Hp2 gene. Malaria is the only significant cause of ahaptoglobinaemia in subjects both with and without detectable parasitaemia. The possible mechanisms involved are discussed.