A case of subacute cutaneous lupus erythematosus as a result of ranibizumab (Lucentis) treatment

Cutaneous lupus erythematosus is a previously undiagnosed side-effect of ranibizumab. Here, we present a case of an 82-year-old female Caucasian patient with wet age-related macular degeneration. Following a single intraocular injection of Lucentis (ranibizumab), she developed a subacute cutaneous lupus erythematosus which, with treatment, took nearly 12 months to resolve. This shows that cutaneous lupus erythematosus is a potential side-effect of many medications, including ranibizumab, as in our case and, in an aging population where polypharmacy is a growing reality, clinicians should be aware of how to diagnose and best manage such cases.     

Maximizing the visual outcome in traumatic cataract cases: The value of a primary posterior capsulotomy and anterior vitrectomy

Objective:

The objective was to provide evidence-based care for patients with traumatic cataracts, we assessed whether a posterior capsulotomy and anterior vitrectomy, as part of the primary surgical procedure, could be a positive predictor of final visual outcome.

Materials and Methods:

This is a prospective randomized control trial. Patients presenting at our hospital between January 2010 and December 2012 having ocular trauma and traumatic cataracts were enrolled, according to the inclusion criteria. We enrolled two groups: Those with and without primary posterior capsulotomy and vitrectomy. Information regarding demographic and ocular trauma were collected using the World Eye Trauma Registry form at the first visit and follow-up, and specific information was collected for both the group who underwent posterior capsulectomies and vitrectomies as a part of the primary procedure, and the control group. Data were analyzed to evaluate the predictive value of primary posterior capsulectomy and anterior vitrectomy.

Results:

We enrolled 120 cases, 60 in each group, comprising 31 females and 89 males. When all other variables were controlled for, the visual outcome (best corrected visual acuity) differed significantly (P < 0.001) between the groups.

Conclusion:

Performance of posterior capsulectomy and anterior vitrectomy as part of the primary procedure improves the final visual outcome.     

Pregnancy and intimate partner violence: how do rural, low-income women cope?

We conducted 32 in-depth interviews with 20 rural, low-income, women residing in the United States who were pregnant (n = 12) or 3 months postpartum (n = 8) and had experienced intimate partner violence (IPV). Using purposive sampling and the grounded theory method, we generated a conceptual model of coping. The urge to protect the unborn baby was the primary influence for participants' decisions about separating from or permanently leaving an abusive relationship. Implications include universal screening for IPV in child-bearing women, inquiry into maternal identity development during pregnancy, and improved resource access for rural, low-income women.     

Monosomy 7/del (7q) in inherited bone marrow failure syndromes: A systematic review

Inherited bone marrow failure syndromes (IBMFS) are rare cancer predisposition syndromes with an especially high risk of transformation to myelodysplastic syndrome (MDS) and/or acute myeloid leukemia (AML). We performed a retrospective systematic review of reported MDS/AML arising in the eight most common IBMFS to determine the frequency and outcome of chromosome 7 abnormalities. We identified 738 MDS/AML cases of 4,293 individuals. Monosomy 7 or del (7q) occurred in ～17%. Greater understanding of the roles played by sequential acquisition of genetic and cytogenetic changes will provide insights into myeloid leukemogenesis and improve the surveillance and hopefully outcomes for individuals with IBMFS.     

Extraction of Value-Added Minerals from Various Agricultural,Industrial and Domestic Wastes

Environmental pollution is one of the major concerns throughout the world. The rise of industrialization has increased the generation of waste materials, causing environmental degradation and threat to the health of living beings. To overcome this problem and effectively handle waste materials, proper management skills are required. Waste as a whole is not only waste, but it also holds various valuable materials that can be used again. Such useful materials or elements need to be segregated and recovered using sustainable recovery methods. Agricultural waste, industrial waste, and household waste have the potential to generate different value-added products. More specifically, the industrial waste like fly ash, gypsum waste, and red mud can be used for the recovery of alumina, silica, and zeolites. While agricultural waste like rice husks, sugarcane bagasse, and coconut shells can be used for recovery of silica, calcium, and carbon materials. In addition, domestic waste like incense stick ash and eggshell waste that is rich in calcium can be used for the recovery of calcium-related products. In agricultural, industrial, and domestic sectors, several raw materials are used; therefore, it is of high economic interest to recover valuable minerals and to process them and convert them into merchandisable products. This will not only decrease environmental pollution, it will also provide an environmentally friendly and cost-effective approach for materials synthesis. These value-added materials can be used for medicine, cosmetics, electronics, catalysis, and environmental cleanup.     

Opening of a cryptic pocket in β-lactamase increases penicillinase activity

Understanding the functional role of protein-excited states has important implications in protein design and drug discovery. However, because these states are difficult to find and study, it is still unclear if excited states simply result from thermal fluctuations and generally detract from function or if these states can actually enhance protein function. To investigate this question, we consider excited states in β-lactamases and particularly a subset of states containing a cryptic pocket which forms under the Ω-loop. Given the known importance of the Ω-loop and the presence of this pocket in at least two homologs, we hypothesized that these excited states enhance enzyme activity. Using thiol-labeling assays to probe Ω-loop pocket dynamics and kinetic assays to probe activity, we find that while this pocket is not completely conserved across β-lactamase homologs, those with the Ω-loop pocket have a higher activity against the substrate benzylpenicillin. We also find that this is true for TEM β-lactamase variants with greater open Ω-loop pocket populations. We further investigate the open population using a combination of NMR chemical exchange saturation transfer experiments and molecular dynamics simulations. To test our understanding of the Ω-loop pocket’s functional role, we designed mutations to enhance/suppress pocket opening and observed that benzylpenicillin activity is proportional to the probability of pocket opening in our designed variants. The work described here suggests that excited states containing cryptic pockets can be advantageous for function and may be favored by natural selection, increasing the potential utility of such cryptic pockets as drug targets.

While it is well established that proteins are dynamic molecules (1), it is often unclear what these dynamics mean for function. An experimentally derived structural snapshot of a protein, such as a crystal structure, is frequently assumed to represent the (highest probability, lowest energy) ground state. This snapshot is also frequently assumed to be the functional state of the protein. In fact, rigidifying the active site or increasing the probability of the ground-state conformation is often used as a design strategy for improving catalytic activity (2, 3). In opposition to this common assumption, there are several compelling examples of functionally relevant excited states (4–9). However, it is still unclear if excited states in general play a role in function.Here, we consider an important class of excited states that contain a “cryptic” pocket, or a pocket which is absent in the ligand-free, experimentally determined structure(s). These states are of particular interest because of the potential utility of cryptic pockets as drug targets (10). These pockets provide a means to drug otherwise “undruggable” proteins and a means to enhance a desired protein activity rather than just inhibit an undesired one (11, 12). One concern, however, with the use of cryptic pockets as drug targets is that it is uncertain if there is a selective pressure to maintain the existence of a given pocket or if drug binding to that pocket could be trivially evolved away. This is at least partially because it is unknown if excited states containing cryptic pockets are simply a byproduct of the dynamic nature of proteins or if they play a bigger role in protein function.Despite the many examples of systems which are known to contain cryptic pockets (13–15), their functional relevance remains unclear because these pockets are notoriously difficult to find and study. Identification of a cryptic pocket often requires simultaneous discovery of a ligand that binds to it (16). Fortunately, recent advances in computational and experimental tools allow us to better identify and study these pockets (1, 17). To increase sampling during molecular dynamics simulations, adaptive sampling methods like fluctuation amplification of specific traits (FAST) (18) and replica exchange methods like sampling water interfaces through scaled Hamiltonians (SWISH) (19) have been developed. To analyze these datasets, methods such as Markov state models (MSMs) (20) and exposons (21) have been developed. These computational tools can then be used to inform experimental methods like room temperature crystallography (22), NMR relaxation techniques (23–25), and thiol-labeling assays (26). Previous work using these methods has shown that many different kinds of proteins have cryptic pockets and that these pockets can be targeted with drugs to allosterically affect functional sites (11, 12, 27, 28). However, it is still unclear if cryptic pockets have implications for function in the absence of ligand binding.To explore the functional relevance of excited states containing cryptic pockets, we consider a set of class A β-lactamases. β-lactamases are enzymes that confer bacteria with antibiotic resistance by hydrolyzing β-lactam antibiotics such as benzylpenicillin and cefotaxime. TEM β-lactamase in particular is an established model system for studying cryptic pockets. TEM has two known and well-characterized cryptic pockets. The first, which was found serendipitously during a drug-screening campaign, is between helices 11 and 12 (16). The second, which was more recently identified in our laboratory (21), forms when the Ω-loop undocks from the protein, so we call this pocket the Ω-loop pocket (Fig. 1). The Ω-loop pocket was discovered in molecular dynamics simulations, confirmed using thiol-labeling experiments, and subsequently shown to exert control over catalysis at the adjacent active site (21). We know the Ω-loop structure is important as it is necessary for the deacylation of β-lactam antibiotics (29), and it has been previously shown that changes in Ω-loop conformations are connected to cefotaxime activity (30, 31).Open in a separate windowFig. 1.The Ω-loop pocket seen in TEM may open in other β-lactamase homologs. The structures of four β-lactamase homologs (Left) overlay well. TEM (Protein Data Base [PDB]: 1xpb) is shown in green, CTX-M-9 (PDB: 1ylj) is shown in cyan, MTB (PDB: 2gdn) is shown in orange, and GNCA (PDB: 4b88) is shown in magenta. The open Ω-loop pocket structure in TEM (Right) was identified in molecular dynamics simulations.As we have also found that the Ω-loop pocket is present in CTX-M-9 β-lactamase (21), we hypothesize that this pocket may play a role in the enzyme’s function. To test this hypothesis, we first examine if the Ω-loop pocket is conserved across β-lactamase homologs and if the presence of the pocket is correlated with increased activity against classic β-lactam substrates. Here, we mean conservation of the phenomenon of cryptic pocket opening rather than conservation of the specific amino acid identities in that region of the protein. We then use activity data for TEM variants and combine NMR with molecular dynamics to gain insight into how the open Ω-loop pocket affects the hydrolysis reaction for different substrates. Finally, we design mutations to modulate the population of the open Ω-loop pocket to explicitly test whether pocket dynamics are predictive of enzymatic activity.     

Relation of urinary endothelin-1 to stress-induced pressure natriuresis in healthy adolescents

We hypothesize that delayed natriuresis during mental stress increases the risk of hypertension and other diseases. Our preclinical studies demonstrate an important role for renal endothelin-1 (ET-1) in regulating sodium excretion. Thus, we predict ET-1 may be linked to the delayed stress response in at-risk individuals. We hypothesize that reduced renal ET-1 accounts for derangements in sodium handling under stress, a link never explored in a large human cohort. We determined urinary ET-1 excretion in three observational studies of changes in sodium excretion during mental stress, in which 776 healthy youth (15–19 years) enrolled in a 5-hour protocol (2 hours of rest before and after 1 hour of mental stress). In all studies, 60-minute urine samples were obtained throughout the protocol. Subjects were grouped as retainers (reduced sodium excretion during stress relative to baseline) or excreters (increased sodium excretion during stress relative to baseline). In excreters, ET-1 excretion was significantly increased from baseline to stress (+0.02 pg/min; P < .001). In contrast, ET-1 excretion was significantly higher (P = .028) in retainers than excreters at baseline but significantly reduced in retainers under stress (?0.02 pg/min; P < .001). ET-1 excretion declined further in retainers during recovery but returned to prestress levels in excreters. Albumin excretion and albumin-to-creatinine ratio were significantly higher in retainers (P = .022, P < .001, respectively). Thus, loss of ET-1–dependent natriuresis may account for sodium retention during stress and may predispose retainers to renal diseases such as hypertension and kidney disease.