Polymerization of Epoxides at a Static Oil-Alkaline Water Interface.

'On-water' catalysis entails the significant enhancement of a chemical reaction by water, even when those reactions are known to be water-sensitive. Here, the findings about the anionic ring opening polymerization of epoxides at the static interface between oil and alkaline water are shared. Unexpectedly, high molar mass fractions are observed with the interfacial system presented herein, albeit at very low conversions (< 5%). Styrene oxide, a notably unreactive epoxide, is chosen as the model compound to investigate the influence of several reaction parameters (i.e., pH, type of the initiator salt, polymerization time, interfacial area, solvent, shaking) on the polymerization. Poly(styrene oxide) (PSO) with an Mn of 5300 g mol-1 is observed via MALDI-ToF MS, with species of at least 8000 g mol-1. The feasibility of expanding the system to (cyclic) aliphatic and aromatic epoxides, and glycidyl ethers is also explored. The system appears to promote polymerization of epoxides that position at the interface, in such a way that initiation and propagation can occur. A mechanistic interpretation of the interfacial polymerization is suggested. The surprising results obtained in this work urge to revisit the role of water in ionic polymerizations.

Orphan lysosomal solute carrier MFSD1 facilitates highly selective dipeptide transport.

Orphan solute carrier (SLC) represents a group of membrane transporters whose exact functions and substrate specificities are not known. Elucidating the function and regulation of orphan SLC transporters is not only crucial for advancing our knowledge of cellular and molecular biology but can potentially lead to the development of new therapeutic strategies. Here, we provide evidence for the biological function of a ubiquitous orphan lysosomal SLC, the Major Facilitator Superfamily Domain-containing Protein 1 (MFSD1), which has remained phylogenetically unassigned. Targeted metabolomics revealed that dipeptides containing either lysine or arginine residues accumulate in lysosomes of cells lacking MFSD1. Whole-cell patch-clamp electrophysiological recordings of HEK293-cells expressing MFSD1 on the cell surface displayed transport affinities for positively charged dipeptides in the lower mM range, while dipeptides that carry a negative net charge were not transported. This was also true for single amino acids and tripeptides, which MFSD1 failed to transport. Our results identify MFSD1 as a highly selective lysosomal lysine/arginine/histidine-containing dipeptide exporter, which functions as a uniporter.

Metastases-directed local therapies (MDT) beyond genuine oligometastatic disease (OMD): Indications, endpoints and the role of imaging.

To further personalise treatment in metastatic cancer, the indications for metastases-directed local therapy (MDT) and the biology of oligometastatic disease (OMD) should be kept conceptually apart. Both need to be vigorously investigated. Tumour growth dynamics - growth rate combined with metastatic seeding efficiency - is the single most important biological feature determining the likelihood of success of MDT in an individual patient, which might even be beneficial in slowly developing polymetastatic disease. This can be reasonably well assessed using appropriate clinical imaging. In the context of considering appropriate indications for MDT, detecting metastases at the edge of image resolution should therefore suggest postponing MDT. While three to five lesions are typically used to define OMD, it could be argued that countability throughout the course of metastatic disease, rather than a specific maximum number of lesions, could serve as a better parameter for guiding MDT. Here we argue that the unit of MDT as a treatment option in metastatic cancer might best be defined not as a single procedure at a single point in time, but as a series of treatments that can be delivered in a single or multiple sessions to different lesions over time. Newly emerging lesions that remain amenable to MDT without triggering the start of a new systemic treatment, a change in systemic therapy, or initiation of best supportive care, would thus not constitute a failure of MDT. This would have implications for defining endpoints in clinical trials and registries: Rather than with any disease progression, failure of MDT would only be declared when there is progression to polymetastatic disease, which then precludes further options for MDT.

Repeated Evolution of Unorthodox Feeding Styles Drives a Negative Correlation between Foot Size and Bill Length in Hummingbirds.

AbstractDifferences among hummingbird species in bill length and shape have rightly been viewed as adaptive in relation to the morphology of the flowers they visit for nectar. In this study we examine functional variation in a behaviorally related but neglected feature: hummingbird feet. We gathered records of hummingbirds clinging by their feet to feed legitimately as pollinators or illegitimately as nectar robbers-"unorthodox" feeding behaviors. We measured key features of bills and feet for 220 species of hummingbirds and compared the 66 known "clinger" species (covering virtually the entire scope of hummingbird body size) with the 144 presumed "non-clinger" species. Once the effects of phylogenetic signal, body size, and elevation above sea level are accounted for statistically, hummingbirds display a surprising but functionally interpretable negative correlation. Clingers with short bills and long hallux (hind-toe) claws have evolved-independently-more than 20 times and in every major clade. Their biomechanically enhanced feet allow them to save energy by clinging to feed legitimately on short-corolla flowers and by stealing nectar from long-corolla flowers. In contrast, long-billed species have shorter hallux claws, as plant species with long-corolla flowers enforce hovering to feed, simply by the way they present their flowers.

Is Elective Total Hip Arthroplasty Safe in Nonagenarians?: An Arthroplasty Registry Analysis.

BACKGROUND: An increasing number of elderly patients are becoming candidates for elective total hip arthroplasty (THA). Conflicting results exist with regard to the safety of THA in nonagenarians. The aims of this study were to evaluate postoperative mortality and morbidity after THA in nonagenarians and underlying risk factors. We hypothesized that nonagenarians undergoing elective THA would show higher morbidity than younger patients and higher mortality than nonagenarians in the general population. METHODS: This was an observational cohort study using data from the German Arthroplasty Registry (Endoprothesenregister Deutschland [EPRD]). Of 323,129 THAs, 263,967 (including 1,859 performed on nonagenarians) were eligible. The mean follow-up (and standard deviation) was 1,070 ± 641 days (range, 0 to 3,060 days). The exclusion criteria were age of <60 years at admission and nonelective THAs or hemiarthroplasties. The cohort was divided into 4 age groups: (1) 60 to 69 years, (2) 70 to 79 years, (3) 80 to 89 years, and (4) ≥90 years. Comorbidities representing independent risk factors for postoperative complications and mortality were identified via a logistic regression model. Mortality rates were compared with those from the general population with data from the Federal Statistical Office. The end points of interest were postoperative major complications, minor complications, and mortality. RESULTS: Among the greatest risk factors for major and minor complications and mortality were congestive heart failure, pulmonary circulation disorders, insulin-dependent diabetes, renal failure, coagulopathy, and fluid and electrolyte disorders. Compared with younger groups, the risks of major and minor complications and mortality were significantly higher in nonagenarians. Mortality increased when major complications occurred. After 1 year, the survival rate in patients without a major complication was 94.4% compared with 79.8% in patients with a major complication. The mortality rates of nonagenarians in the study population were lower than those in the corresponding age group of the general population. The 1-year mortality rates at 90 years of age were 10.5% for men and 6.4% for women within the study group compared with 18.5% for men and 14.7% for women among the general population. CONCLUSIONS: Comorbidities favor the occurrence of complications after elective THA in nonagenarians and thus increase postoperative morbidity. In the case of complications, mortality is also increased. The fact that mortality is still lower than within the general population shows that this aspect can be controlled by careful patient selection and adequate preparation. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Ang II Promotes ET-1 Production by Regulating NOX2 Activity Through Transcription Factor Oct-1.

BACKGROUND: Increasing evidence suggests that superoxide ions produced by NOX (nicotinamide adenine dinucleotide phosphate oxidases) mediate vascular effects of Ang II (angiotensin II) evoked by atherogenic diets. Here, we analyzed the mechanism by which NOX2 contributes to Ang II-induced ET-1 (endothelin 1) production in human microvascular endothelial cells. METHODS: The effects of high-fat diet were compared between WT (wild type) and Nox2 (mouse NOX2 gene)-deficient mice. ET-1 production and NOX2 expression by human microvascular endothelial cells in vitro were analyzed by ELISA, reverse transcription quantitative polymerase chain reaction, electrophoretic mobility shift assay, promoter deletions, RNA interference, and pharmacological inhibition. Production of superoxide anions was visualized by fluorescent cell labeling. RESULTS: Feeding mice high-fat diet for 10 weeks increased cardiac expression and plasma levels of Ang II and ET-1 in WT but not in Nox2-deficient animals. Exposure of human microvascular endothelial cells to Ang II resulted in increased ET-1 production, which could be blocked by silencing NOX2 (human NOX2 gene). Ang II promoted NOX2 expression through induction of the Oct-1 (human/mouse octamer binding transcription factor 1 protein) and activation of the NOX2 promoter region containing Oct-1-binding sites. Stimulation of NOX2 expression by Ang II was associated with increased production of superoxide anions. Inhibition of Oct-1 by small interfering RNA reduced Ang II-induced NOX2 expression and superoxide anion production, and neutralization of superoxide by SOD (superoxide dismutase) abolished Ang II-stimulated ET1 (human ET-1 gene) promoter activity, ET1 mRNA expression, and ET-1 release. CONCLUSIONS: Ang II may promote ET-1 production in the endothelium in response to atherogenic diets through a mechanism that involves the transcription factor Oct-1 and the increased formation of superoxide anions by NOX2.

Structural basis of a two-step tRNA recognition mechanism for plastid glycyl-tRNA synthetase.

Two types of glycyl-tRNA synthetase (GlyRS) are known, the α2 and the α2ß2 GlyRSs. Both types of synthetase employ a class II catalytic domain to aminoacylate tRNAGly. In plastids and some bacteria, the α and ß subunits are fused and are designated as (αß)2 GlyRSs. While the tRNA recognition and aminoacylation mechanisms are well understood for α2 GlyRSs, little is known about the mechanisms for α2ß2/(αß)2 GlyRSs. Here we describe structures of the (αß)2 GlyRS from Oryza sativa chloroplast by itself and in complex with cognate tRNAGly. The set of structures reveals that the U-shaped ß half of the synthetase selects the tRNA in a two-step manner. In the first step, the synthetase engages the elbow and the anticodon base C35 of the tRNA. In the second step, the tRNA has rotated ∼9° toward the catalytic centre. The synthetase probes the tRNA for the presence of anticodon base C36 and discriminator base C73. This intricate mechanism enables the tRNA to access the active site of the synthetase from a direction opposite to that of most other class II synthetases.

Fibula pro tibia and cancellous allograft vitalised with autologous bone for non-union of the distal tibia diaphysis: Surgical technique.

Background: The management of medium-sized osseous defects and pseudoarthrosis of the tibia is challenging. This surgical technique aims to bridge medium-sized tibial defects using the fibula as a lead structure. The fibula and cancellous bone graft fuse with the tibia leading to synostosis. Methods: Cortico-cancellous bone is harvested from the anterior iliac crest. The bone is shredded into small pieces of about 5 mm and mixed with stem cell-rich blood from the situs. Additionally, cancellous allografts can be used for expansion. The approach is extended along the interosseous membrane to reach the tibial defect. The pseudarthrosis is debrided and the tibial bone adjacent to the defect is decorticated. A 3.5 mm 1/3 tube plate is positioned to the fibula and fixed. Four quadricortical screws are positioned. Autograft is secured into the tibial bone defect and between the fibula and the tibia directly on the anterior surface of the interosseous membrane. Results: 15 patients were followed up for a mean of 17 months. Osseous consolidation was achieved in 73.3% of all cases. On average, bone healing has occurred 17 weeks postoperatively. These patients did not have any pain walking with full weight bearing and without any walking aids at the last follow-up. Conclusion: The fibula pro tibia procedure is a sufficient tool for treating non-unions of the mid and distal third of the tibia diaphysis in cases with a bony defect size of 1 cm-6 cm.

Missed or delayed diagnosis of anorectal malformations: a review of the literature, current training and practice in the UK in relation to detection via the NIPE programme.

Anorectal malformations (ARMs) are a spectrum of congenital anomalies where there is abnormal development of the anus and rectum. With an incidence of 1:5000 live births and affecting both males and females, these anomalies vary in their appearance and presentation, lack features enabling antenatal detection and should be detected at birth by the examining midwife or within 72 hours through the newborn and infant physical examination (NIPE) screening programme. However, it is recognised that the diagnosis of ARMs can be missed or delayed leading to morbidity and mortality. In the UK, despite the existence of the NIPE screening programme and NICE guidelines, published literature shows that nearly a quarter of ARMs are not diagnosed at birth. This review takes a critical look at the frequency of missed/delayed diagnosis of ARMs at birth, the implications of delayed diagnosis, and the possible reasons for this related to education and training of healthcare professionals involved in newborn examination, focusing on the UK national screening programme for NIPE. We propose a strategy for enhancing detection of ARMs in a timely manner through the existing framework of the NIPE screening programme.

The Female Pelvis Is Associated with a Lateralized Ischium and a Reduced Ischiofemoral Space.

BACKGROUND: Pelvi-femoral conflicts are increasingly recognized for their explanatory role in the pathology of extra-articular hip impingement. Ischiofemoral impingement (IFI) is a type of impingement between the femur and the ischium that causes high femoral antetorsion and valgus femoral neck orientation. It is unknown whether obstetric adaptation of the female pelvis renders the female hip at a higher risk of sustaining IFI. The aim of this study was to determine the influence of the pelvic morphology on the ischiofemoral space (IFS). METHODS: Plain radiographs of healthy individuals with no symptomatic hip disease were obtained in a functional standing position in a standardized manner and utilized for measurement of the interischial and ischiofemoral widths, subpubic angle, and centrum collum diaphyseal (CCD) angle. Linear regression was performed to determine the influence of morphometric measures on the ischiofemoral space. RESULTS: Sixty-five radiographs (34 females and 31 males) were included. The cohort was stratified according to gender. Significant gender-related differences were noted regarding the ischiofemoral distance (31% increase in males, p < 0.001), pubic-arc angle (30% increased in females, p < 0.001), and the interischial space (7% increase in females, p < 0.001). CCD did not significantly differ between genders (p = 0.2). Factors influencing the IFS include the pubic-arc angle (ß = -0.01 (CI -0.02--0.00), p = 0.003), interischial distance (ß = -0.11 (CI -0.23--0.00), p = 0.049) and CCD (ß = -0.06 (CI -0.09--0.04), p < 0.001). CONCLUSIONS: Obstetric adaptation is associated with an increased subpubic angle that shifts the ischia laterally and away from the symphysis. The resultant reduction in the ischiofemoral space renders the female pelvis at a higher risk for a pelvi-femoral conflict, or more precisely, an ischiofemoral conflict, due to the reduced ischiofemoral space of the hip. The CCD angle of the femur was shown not to be gender specific. However, the CCD angle demonstrates an influence on the ischiofemoral space, rendering the proximal femur a target for corresponding osteotomies.

Survival of the dysplastic hip after periacetabular osteotomy: a meta-analysis.

BACKGROUND: Periacetabular osteotomy (PAO) has become a popular procedure for re-orientation of the acetabulum in patients with a developmental pathomorphology. Since its first description by Reinhold Ganz in 1988, many institutions worldwide have adopted the procedure for the treatment of developmental hip dysplasia (DDH) and have subsequently reported their results. The aim of this study was to provide a meta-analysis of the likelihood of long-term survival of a dysplastic hip after PAO. METHODS: A systematic literature review was conducted using Medline, Cochrane and "Web of Science" databases to identify articles reporting survival estimates for PAO in patients with DDH. To be included in the analysis, studies had to include patient cohorts aged <40 years, with Osteoarthritis grade < Tönnis III and no form of neuromuscular dysplasia. Adjustment for cohort overlap was performed. Quality assessment included level of evidence (LOE) according to the oxford center for LOE criteria and the "Methodological index for non-randomized studies (MINORS)". After data extraction, a random-effects meta-analytical model was applied to provide weighted mean estimates of survival at 5 years, 10 years, 15 years and 20 years. RESULTS: Nine relevant articles included 2268 dysplastic hips that underwent PAO in 9 institutions. Of the included studies, 5 presented level III evidence and 4 presented level IV evidence. The MINORS score was 11 for 3 studies, 12 for 4 studies and 13 for 2 studies. The 5-year survival after PAO was 96.1% (95% CI, 94.9-97.3), the 10-year survival was 91.3% (95% CI, 87.7-94.8), 15-year survival 85.0% (95% CI, 78.9-91.1), 20-year survival 67.6% (95% CI, 53.9-81.3). CONCLUSIONS: The results provide a representative survival estimate of a dysplastic hip after PAO based on global evidence. This should provide clinicians and patients with an adequate reflection of prognostic expectations after this kind of surgery.

Transcription-Translation Coupling in Bacteria.

In bacteria, transcription and translation take place in the same cellular compartment. Therefore, a messenger RNA can be translated as it is being transcribed, a process known as transcription-translation coupling. This process was already recognized at the dawn of molecular biology, yet the interplay between the two key players, the RNA polymerase and ribosome, remains elusive. Genetic data indicate that an RNA sequence can be translated shortly after it has been transcribed. The closer both processes are in time, the less accessible the RNA sequence is between the RNA polymerase and ribosome. This temporal coupling has important consequences for gene regulation. Biochemical and structural studies have detailed several complexes between the RNA polymerase and ribosome. The in vivo relevance of this physical coupling has not been formally demonstrated. We discuss how both temporal and physical coupling may mesh to produce the phenomenon we know as transcription-translation coupling.

Full-length standing radiographs can be used for determination of the Femoral neck-shaft angle but not acetabular coverage.

INTRODUCTION: The exact evaluation of hip morphology is essential for surgical planning. A wide range of morphometric measures of the acetabulum is deduced from conventional anterior-posterior (ap) pelvic radiographs. Full-length weight-bearing radiographs (FLWBR) also depict the acetabulum and are commonly used for osteotomy planning of the lower limb. This study aimed to determine whether FLWBR can be used to evaluate acetabular morphology. METHODS: Radiographs of patients receiving a hip workup that included a conventional ap pelvic X-ray and FLWBR were utilized for radiographic measurements. The following parameters were measured: extrusion index of the femoral head, anterior wall index, posterior wall index, lateral center edge angle (LCE), acetabular index, pubic arc angle (subpubic angle), and centrum-collum-diaphyseal angle (CCD). RESULTS: FLWBR depicted a significantly reduced anterior coverage (p = 0.049) and increased posterior coverage (p < 0.001), higher acetabular index (p = 0.015), and higher pubic-arc angle (p = 0.02) compared to conventional ap pelvic radiographs. There were no significant differences regarding the CCD angle (p = 0.28), extrusion index (p = 0.31), and LCE (p = 0.16). DISCUSSION: The CCD angle of the femur can be measured on conventional ap radiographs and full-length weight-bearing X-rays for lower limb deformity analysis. However, FLWBR will depict an anteverted acetabular morphology, rendering conventional ap radiographs necessary for planning pelvic osteotomies.

Addition of the nuclear export inhibitor selinexor to standard intensive treatment for elderly patients with acute myeloid leukemia and high risk myelodysplastic syndrome.

Treatment results of AML in elderly patients are unsatisfactory. In an open label randomized phase II study, we investigated whether addition of the XPO1 inhibitor selinexor to intensive chemotherapy would improve outcome in this population. 102 AML patients > 65 years of age (median 69 (65-80)) were randomly assigned to standard chemotherapy (3 + 7) with or without oral selinexor 60 mg twice weekly (both arms n = 51), days 1-24. In the second cycle, cytarabine 1000 mg/m2 twice daily, days 1-6 with or without selinexor was given. CR/CRi rates were significantly higher in the control arm than in the investigational arm (80% (95% C.I. 69-91%) vs. 59% (45-72%; p = 0.018), respectively). At 18 months, event-free survival was 45% for the control arm versus 26% for the investigational arm (Cox-p = 0.012) and overall survival 58% vs. 33%, respectively (p = 0.009). AML and infectious complications accounted for an increased death rate in the investigational arm. Irrespective of treatment, MRD status after two cycles appeared to be correlated with survival. We conclude that the addition of selinexor to standard chemotherapy does negatively affect the therapeutic outcome of elderly AML patients. (Netherlands Trial Registry number NL5748 (NTR5902), www.trialregister.nl ).

Anterolateral Extraarticular Stabilisation of the Knee: Modified Lemaire Procedure.

The anterolateral aspect of the knee is prone to laxity or symptomatic instability, if the anterior cruciate ligament (ACL) is torn. It is necessary to address this issue in patients with general joint hyperlaxity, overextension of the knee, massive anterolateral instability, or re-tear of the ACL with chronic instability. In these cases, and in addition to a preoperative bony workup and revision ACL reconstruction, anterolateral stabilisation should be considered to avoid persistent anterolateral rotation instability and failure of the ACL reconstruction.To stabilise the anterolateral corner of the knee, the modified Lemaire procedure as presented and illustrated here is a straight forward surgical technique that can be performed right after standard ACL reconstruction surgery, if indicated. It is independent from the graft choice for the ACL reconstruction, and the surgical setting in the operating room remains unchanged.

Chronic post-COVID-19 syndrome and chronic fatigue syndrome: Is there a role for extracorporeal apheresis?

As millions of patients have been infected by SARS-CoV-2 virus a vast number of individuals complain about continuing breathlessness and fatigue even months after the onset of the disease. This overwhelming phenomenon has not been well defined and has been called "post-COVID syndrome" or "long-COVID" [1]. There are striking similarities to myalgic encephalomyelitis also called chronic fatigue syndrome linked to a viral and autoimmune pathogenesis. In both disorders neurotransmitter receptor antibodies against ß-adrenergic and muscarinic receptors may play a key role. We found similar elevation of these autoantibodies in both patient groups. Extracorporeal apheresis using a special filter seems to be effective in reducing these antibodies in a significant way clearly improving the debilitating symptoms of patients with chronic fatigue syndrome. Therefore, such a form of neuropheresis may provide a promising therapeutic option for patients with post-COVID-19 syndrome. This method will also be effective when other hitherto unknown antibodies and inflammatory mediators are involved.

Frontal knee alignment influences the vertical orientation of the femoral neck in standing position.

AIMS: The aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck. METHODS: Long-leg standing radiographs of patients undergoing realignment surgery around the knee were used. The hip-knee-ankle angle (HKA) and the vertical orientation of the femoral neck in relation to the floor were measured, prior to surgery and after osteotomy-site-union. Linear regression was performed to determine the influence of knee alignment on the vertical orientation of the femoral neck. RESULTS: The cohort included 147 patients who underwent knee realignment-surgery. The mean age was 51.5 years (SD 11). Overall, 106 patients underwent a valgisation-osteotomy, while 41 underwent varisation osteotomy. There was a significant association between the orientation of the knee and the coronal neck-orientation. In the varus group, the median orientation of the femoral neck was 46.5° (interquartile range (IQR) 49.7° to 50.0°), while in the valgus group, the orientation was 52.0° (IQR 46.5° to 56.7°; p < 0.001). Linear regression analysis revealed that HKA demonstrated a direct influence on the coronal neck-orientation (ß = 0.5 (95% confidence interval (CI) 0.2 to 0.7); p = 0.002). Linear regression also showed that realignment surgery was associated with a significant influence on the change in the coronal femoral neck orientation (ß = 5.6 (95% CI 1.5 to 9.8); p = 0.008). CONCLUSION: Varus or valgus knee alignment is associated with either a more horizontal or a more vertical femoral neck orientation in standing position, respectively. Subsequently, osteotomies around the knee alter the vertical orientation of the femoral neck. These aspects are of importance when planning osteotomies around the knee in order to appreciate the effects on the adjacent hip joint. The concept may be of even more relevance in dysplastic hips. Cite this article: Bone Jt Open 2021;2(12):1057-1061.

The Lysozyme Inhibitor Thionine Acetate Is Also an Inhibitor of the Soluble Lytic Transglycosylase Slt35 from Escherichia coli.

Lytic transglycosylases such as Slt35 from E. coli are enzymes involved in bacterial cell wall remodelling and recycling, which represent potential targets for novel antibacterial agents. Here, we investigated a series of known glycosidase inhibitors for their ability to inhibit Slt35. While glycosidase inhibitors such as 1-deoxynojirimycin, castanospermine, thiamet G and miglitol had no effect, the phenothiazinium dye thionine acetate was found to be a weak inhibitor. IC50 values and binding constants for thionine acetate were similar for Slt35 and the hen egg white lysozyme. Molecular docking simulations suggest that thionine binds to the active site of both Slt35 and lysozyme, although it does not make direct interactions with the side-chain of the catalytic Asp and Glu residues as might be expected based on other inhibitors. Thionine acetate also increased the potency of the beta-lactam antibiotic ampicillin against a laboratory strain of E. coli.