Spliced FKBP51s predicts unfavorable prognosis of glioblastoma patients

The primary treatment for glioblastoma (GBM) is removing the tumor mass as defined by magnetic resonance imaging (MRI). However, MRI has limited diagnostic and predictive value. Tumor-associated macrophages (TAMs) are abundant in GBM microenvironment (TME) and are found in peripheral blood (PB). FKBP51 expression, with its canonical and spliced isoforms, is constitutive in immune cells and aberrant in GBM. Spliced FKBP51s supports M2-polarization. To find an immunological signature that combined with MRI could advance in diagnosis, we immunophenotyped the macrophages of TME and PB from 37 GBM patients using FKBP51s and classical M1-M2 markers. We also determined the tumor levels of FKBP51s, PD-L1, and HLA-DR. Tumors expressing FKBP51s showed an increase in various M2 phenotypes and Tregs in PB, indicating immunosuppression. Tumors expressing FKBP51s also activated STAT3 and were associated with reduced survival. Correlative studies with MRI and tumor/macrophages co-cultures allowed to interpret TAMs. Tumor volume correlated with M1 infiltration of TME. Co-cultures with spheroids produced M1 polarization, suggesting that M1 macrophages may infiltrate alongside cancer stem-cells. Co-cultures of adherent cells developed the M2 phenotype CD163/FKBP51s expressing pSTAT6, a transcription factor enabling migration and invasion. In patients with recurrences, increased counts of CD163/FKBP51s monocyte/macrophages in PB correlated with callosal infiltration and was accompanied by a concomitant decrease in TME-infiltrating M1 macrophages. PB PD-L1/FKBP51s connoted necrotic tumors. In conclusion, FKBP51s identifies a GBM subtype that significantly impairs the immune system. Moreover, FKBP51s marks PB macrophages associated with MRI features of glioma malignancy that can aid in patient monitoring.

Metabolic vulnerability of cancer stem cells and their niche

Cancer stem cells (CSC) are the leading cause of the failure of anti-tumor treatments. These aggressive cancer cells are preserved and sustained by adjacent cells forming a specialized microenvironment, termed niche, among which tumor-associated macrophages (TAMs) are critical players. The cycle of tricarboxylic acids, fatty acid oxidation path, and electron transport chain have been proven to play central roles in the development and maintenance of CSCs and TAMs. By improving their oxidative metabolism, cancer cells are able to extract more energy from nutrients, which allows them to survive in nutritionally defective environments. Because mitochondria are crucial bioenergetic hubs and sites of these metabolic pathways, major hopes are posed for drugs targeting mitochondria. A wide range of medications targeting mitochondria, electron transport chain complexes, or oxidative enzymes are currently investigated in phase 1 and phase 2 clinical trials against hard-to-treat tumors. This review article aims to highlight recent literature on the metabolic adaptations of CSCs and their supporting macrophages. A focus is provided on the resistance and dormancy behaviors that give CSCs a selection advantage and quiescence capacity in particularly hostile microenvironments and the role of TAMs in supporting these attitudes. The article also describes medicaments that have demonstrated a robust ability to disrupt core oxidative metabolism in preclinical cancer studies and are currently being tested in clinical trials.

NLRP3, the inflammasome and COVID-19 infection

Severe coronavirus disease 2019 (COVID-19) is characterized by respiratory failure, shock or multiorgan dysfunction, often accompanied by systemic hyperinflammation and dysregulated cytokine release. These features are linked to the intense and rapid stimulation of the innate immune response. The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome is a central player in inflammatory macrophage activation which via caspase-1 activation leads to the release of the mature forms of the proinflammatory cytokines interleukin (IL)-1β and IL-18, and via cleavage of Gasdermin D pyroptosis, an inflammatory form of cell death. Here, we discuss the role of NLRP3 activation in COVID-19 and clinical trials currently underway to target NLRP3 to treat severe COVID-19.

FKBP51 plays an essential role in Akt ubiquitination that requires Hsp90 and PHLPP

FKBP51 plays a relevant role in sustaining cancer cells, particularly melanoma. This cochaperone participates in several signaling pathways. FKBP51 forms a complex with Akt and PHLPP, which is reported to dephosphorylate Akt. Given the recent discovery of a spliced FKBP51 isoform, in this paper, we interrogate the canonical and spliced isoforms in regulation of Akt activation. We show that the TPR domain of FKBP51 mediates Akt ubiquitination at K63, which is an essential step for Akt activation. The spliced FKBP51, lacking such domain, cannot link K63-Ub residues to Akt. Unexpectedly, PHLPP silencing does not foster phosphorylation of Akt, and its overexpression even induces phosphorylation of Akt. PHLPP stabilizes levels of E3-ubiquitin ligase TRAF6 and supports K63-ubiquitination of Akt. The interactome profile of FKBP51 from melanoma cells highlights a relevant role for PHLPP in improving oncogenic hallmarks, particularly, cell proliferation.

Alternative splicing of FKBP5 gene exerts control over T lymphocyte expansion

FKBP51 is constitutively expressed by immune cells. As other FKBP family members, FKBP51 acts as a coreceptor for the natural products FK506 and rapamycin, which exhibit immunosuppressive effects. However, little is known about the intrinsic role of this large FKBP in the primary function of lymphocytes, that is, the adaptive immune response against foreign antigens, for example, pathogens. This paper aimed to investigate whether FKBP51 expression was modulated during lymphocyte activation. Moreover, as we recently identified a splicing isoform of FKBP51, namely FKBP51s, we also measured this splice protein, along with the canonical one, at different times of a peripheral blood mononuclear cell culture stimulated via T cell receptor. Our results show that the two FKBP51 isoforms were alternatively induced during the proliferative burst. Canonical FKBP51 increased in the time window between 48 and 96 h and its expression levels correlated with cyclin D levels. FKBP51s transiently increased earlier, at 24-36 h to reappearing later, at 120 h, when cyclin D expression returned at resting levels and proliferation ceased. Interestingly, within these two specific timeframes, FKBP51s accumulated in the nucleus. Here FKBP51s colocalized with the Foxp3 transcription factor at 36 h. Regulatory T cell (Treg) counts significantly decreased when FKBP51s was downmodulated. The coculture suppression assay suggested that FKBP51s supports the suppressive capability of Tregs. At 120 h, chromatin immunoprecipitation experiments found FKBP51s linked to CCND1 gene, suggesting a possible effect on gene transcription regulation, as previously demonstrated in melanoma. In conclusion, our study shows that FKBP5 isoforms are upregulated during lymphocyte activation, albeit on different timeframes. The activation of canonical FKBP51 coincides with proliferation hallmarks; FKBP5 splicing occurs early to sustain Treg development and late when proliferation ceases.

Behavioral avoidance of contagious and non-contagious adults

Evolutionary theories of disease avoidance propose that humans have a set of universal psychological processes to detect environmental cues indicative of infectious disease. These processes then initiate cognitive, emotional, and behavioral responses that function to limit contact with harmful pathogens. Here, we study the conditions under which people exhibit behavioral avoidance of others with a contagious illness or a physical injury (i.e., a broken leg), and the potential mechanisms that underlie this behavior. Across three studies, participants were given the option of sitting at one of two workstations previously occupied by two confederates, one of whom either showed visible symptoms of a cold (contagion condition), wore a lower-leg orthopedic boot and used crutches (broken leg condition), or showed no signs of illness or physical injury (control). We found strong evidence that adults explicitly avoid contact with individuals who show symptoms of a contagious illness. Further, we provide some evidence that adults also avoid individuals with a physical injury, but that this behavior might be driven by implicit, unconscious processes. The findings are discussed in terms of implications for the healthy avoidance of contagion, and the risk for potential stigmatization of non-contagious groups.

Death Related to a Congenital Vascular Anomaly of Pulmonary Hamartoma Type: Malpractice or Tragic Fatality?

In forensic pathology, apparently straightforward cases can often hide rarities that, if not correctly interpreted, can alter the results of the entire investigation, leading to misinterpretations. This occurs when the investigation is conducted to assess medical malpractice. An unexpected death, with no known apparent cause, is often linked to an underlying disease process of unclear etiological origin whose nature can, unfortunately, be properly investigated only post-mortem. This presentation shows a case study, in which it was possible to reconduct the death of a patient to a natural pathology and not to medical treatment. Here, the authors illustrate a case with a hamartoma developed in chronic inflammatory conditions (bronchiectasis) that was difficult to differentiate from lung cancer due to the inability to perform specific instrumental examinations. The hamartoma, usually benign and identifiable by standard instrumental investigations, in this case, led to the patient's death precisely during the execution of a bronchoscopy. However, in the absence of a certain cause of death, public opinion unanimously attributes a patient's disease to medical error. Indeed, a routine practice such as bronchoscopy should not cause death and consequently, the doctor must have made a mistake. Fortunately, the autopsy not only demonstrated the origin of the bleeding but also unveiled the reason for this, as rare congenital lung disease. Fate, one might say.

Long-chain polyphosphates impair SARS-CoV-2 infection and replication

Long-chain, inorganic polyphosphates (polyPs), which are found in many cells in the blood, have cytoprotective and antiviral activities, particularly against HIV-1 infection. Ferrucci et al. tested the effects of polyPs of various lengths on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. Molecular docking and binding analyses showed that polyPs bound to the host receptor ACE2, which facilitates viral entry, and a viral RNA polymerase required for replication. Both proteins underwent proteasomal degradation in cells incubated with polyP120, the optimal species tested, resulting in inhibition of SARS-CoV-2 replication and a reduced inflammatory response. Given that polyPs have low toxicity, these results suggest that their potential therapeutic use should be further explored.

Inorganic polyphosphates (polyPs) are linear polymers composed of repeated phosphate (PO₄³⁻) units linked together by multiple high-energy phosphoanhydride bonds. In addition to being a source of energy, polyPs have cytoprotective and antiviral activities. Here, we investigated the antiviral activities of long-chain polyPs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In molecular docking analyses, polyPs interacted with several conserved amino acid residues in angiotensin-converting enzyme 2 (ACE2), the host receptor that facilitates virus entry, and in viral RNA-dependent RNA polymerase (RdRp). ELISA and limited proteolysis assays using nano– LC-MS/MS mapped polyP120 binding to ACE2, and site-directed mutagenesis confirmed interactions between ACE2 and SARS-CoV-2 RdRp and identified the specific amino acid residues involved. PolyP120 enhanced the proteasomal degradation of both ACE2 and RdRp, thus impairing replication of the British B.1.1.7 SARS-CoV-2 variant. We thus tested polyPs for functional interactions with the virus in SARS-CoV-2–infected Vero E6 and Caco2 cells and in primary human nasal epithelial cells. Delivery of a nebulized form of polyP120 reduced the amounts of viral positive-sense genomic and subgenomic RNAs, of RNA transcripts encoding proinflammatory cytokines, and of viral structural proteins, thereby presenting SARS-CoV-2 infection in cells in vitro.

Prune-1 drives polarization of tumor-associated macrophages (TAMs) within the lung metastatic niche in triple-negative breast cancer

M2-tumor-associated macrophages (M2-TAMs) in the tumor microenvironment represent a prognostic indicator for poor outcome in triple-negative breast cancer (TNBC).

Here we show that Prune-1 overexpression in human TNBC patients has positive correlation to lung metastasis and infiltrating M2-TAMs. Thus, we demonstrate that Prune-1 promotes lung metastasis in a genetically engineered mouse model of metastatic TNBC augmenting M2-polarization of TAMs within the tumor microenvironment. Thus, this occurs through TGF-β enhancement, IL-17F secretion, and extracellular vesicle protein content modulation.

We also find murine inactivating gene variants in human TNBC patient cohorts that are involved in activation of the innate immune response, cell adhesion, apoptotic pathways, and DNA repair. Altogether, we indicate that the overexpression of Prune-1, IL-10, COL4A1, ILR1, and PDGFB, together with inactivating mutations of PDE9A, CD244, Sirpb1b, SV140, Iqca1, and PIP5K1B genes, might represent a route of metastatic lung dissemination that need future prognostic validations.

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Prune-1 correlates to M2-TAMs confirming lung metastatic dissemination in GEMM

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Cytokines and EV proteins are responsible of M2-TAMs polarization processes

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A small molecule with immunomodulatory properties ameliorates metastatic dissemination

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Identification of gene variants within immune response and cell adhesion in TNBC

Early interventions in a US military FIRST episode psychosis program

AIM

Naval Medical Center San Diego's Psychiatric Transition Program is a specialized first episode psychosis treatment program that delivers coordinated specialty care to military service members with psychotic disorders. Due to the unique military environment, military service members with first episode psychosis are hypothesized to receive care very early after the emergence of first psychotic symptoms, resulting in significantly reduced duration of untreated psychosis. This study's aim is to calculate the duration of untreated psychosis for patients enrolled in Naval Medical Center San Diego's Psychiatric Transition Program (NMCSD PTP) from 01JUL2014-31DEC2016.

METHODS

Patients included in this study had a diagnosis of schizophreniform disorder (13.04%), schizophrenia (43.48%), schizoaffective disorder (8.70%), other specified schizophreniform disorder (30.43%), or brief psychotic disorder (4.35%) upon discharge from military service and NMCSD PTP. Duration of untreated psychosis was defined as the interval from emergence of positive psychotic symptoms to antipsychotic medication initiation. Duration of untreated psychosis was measured through retrospective review of the electronic medical record. A total of 69 subjects in the Naval Medical Center San Diego's Psychiatric Transition Program met inclusion criteria. Mean and median values as well as standard deviations were calculated for all included subjects.

RESULTS

The mean duration to scheduled (non-PRN) neuroleptic medication was 37 days (median: 4 days). The mean duration to PRN neuroleptic medication was 21 days (median: 2 days).

CONCLUSIONS

These data support our view that the structure of the military and military healthcare system markedly shortens the DUP for military service members who experience first episode psychosis.

Structural and Kinetic Studies of the Potent Inhibition of Metallo-β-lactamases by 6-Phosphonomethylpyridine-2-carboxylates

There are currently no clinically available inhibitors of metallo-β-lactamases (MBLs), enzymes that hydrolyze β-lactam antibiotics and confer resistance to Gram-negative bacteria. Here we present 6-phosphonomethylpyridine-2-carboxylates (PMPCs) as potent inhibitors of subclass B1 (IMP-1, VIM-2, and NDM-1) and B3 (L1) MBLs. Inhibition followed a competitive, slow-binding model without an isomerization step (IC₅₀ values of 0.3-7.2 μM; K_i values of 0.03-1.5 μM). Minimum inhibitory concentration assays demonstrated potentiation of β-lactam (Meropenem) activity against MBL-producing bacteria, including clinical isolates, at concentrations at which eukaryotic cells remain viable. Crystal structures revealed unprecedented modes of binding of inhibitor to B1 (IMP-1) and B3 (L1) MBLs. In IMP-1, binding does not replace the nucleophilic hydroxide, and the PMPC carboxylate and pyridine nitrogen interact closely (2.3 and 2.7 Å, respectively) with the Zn2 ion of the binuclear metal site. The phosphonate group makes limited interactions but is 2.6 Å from the nucleophilic hydroxide. Furthermore, the presence of a water molecule interacting with the PMPC phosphonate and pyridine N-C2 π-bond, as well as the nucleophilic hydroxide, suggests that the PMPC binds to the MBL active site as its hydrate. Binding is markedly different in L1, with the phosphonate displacing both Zn2, forming a monozinc enzyme, and the nucleophilic hydroxide, while also making multiple interactions with the protein main chain and Zn1. The carboxylate and pyridine nitrogen interact with Ser221 and -223, respectively (3 Å distance). The potency, low toxicity, cellular activity, and amenability to further modification of PMPCs indicate these and similar phosphonate compounds can be further considered for future MBL inhibitor development.

Outcomes associated with fetal hepatobiliary cysts: systematic review and meta-analysis

OBJECTIVE

To explore the outcomes associated with fetal hepatobiliary cysts.

METHODS

MEDLINE and EMBASE were searched for studies reporting on outcomes of fetal hepatobiliary cysts. Outcomes observed were resolution/reduction and increase in cyst size, associated congenital anomalies of the biliary tract and liver, abnormal postnatal liver function tests, clinical symptoms, need for surgery, postsurgical complications and predictive accuracy of prenatal ultrasound in identifying correctly hepatobiliary cysts. Meta-analysis of proportions was used to analyze the data.

RESULTS

The search identified 1498 articles, and 22 studies (252 fetuses) were included in the systematic review. For fetal hepatic cysts, resolution or reduction in cyst size either pre- or postnatally occurred in 59.3% (95% CI, 30.9-84.7%) of cases, while an increase in cyst size occurred in 8.7% (95% CI, 1.1-22.4%). No case of hepatic cyst had associated malformations of the biliary tract at birth. Clinical symptoms occurred in 14.8% (95% CI, 6.3-26.1%) of cases and, in 5.4% (95% CI, 0.9-13.6%), they were related to the presence of bile obstruction due to compression of the cyst on the biliary tract. No case of hepatic cyst had abnormal liver function at birth. For fetal biliary cysts, resolution or reduction in cyst size occurred in 8.7% (95% CI, 2.7-17.5%) of cases and an increase in size occurred in 34.4% (95% CI, 20.5-49.8%). Congenital anomalies of the biliary tract and liver, such as fibrosis, occurred in 21.5% (95% CI, 10.2-35.6%) and 17.4% (95% CI, 5.4-34.4%) of cases, respectively. 57.3% (95% CI, 33.9-79.0%) of cases showed impairment in liver function after birth, while 55.0% (95% CI, 37.5-71.9%) showed clinical symptoms, mainly due to bile obstruction (47.9% (95% CI, 29.4-66.7%)). Postsurgical complications occurred in 10.9% (95% CI, 3.7-21.3%) of operated cases. Risk assessment according to different cut-offs of cyst size could not be performed in view of the very small number of included studies.

CONCLUSIONS

Fetal hepatic cysts are benign, with a low likelihood of associated anomalies of the hepatobiliary tract, abnormal liver function or clinical symptoms. Congenital biliary cysts are associated with a high rate of progression, abnormal liver function after birth and clinical symptoms. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Outcome of fetal ovarian cysts diagnosed on prenatal ultrasound examination: systematic review and meta-analysis

OBJECTIVE

To explore the outcome of fetuses with a prenatal diagnosis of ovarian cyst.

METHODS

The electronic databases MEDLINE and EMBASE were searched using keywords and word variants for 'ovarian cysts', 'ultrasound' and 'outcome'. The following outcomes in fetuses with a prenatal diagnosis of ovarian cyst were explored: resolution of the cyst, change of ultrasound pattern of the cyst, occurrence of ovarian torsion and intracystic hemorrhage, need for postnatal surgery, need for oophorectomy, accuracy of prenatal ultrasound examination in correctly identifying ovarian cyst, type of ovarian cyst at histopathological analysis and intrauterine treatment. Meta-analyses using individual data random-effects logistic regression and meta-analyses of proportions were performed. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale.

RESULTS

Thirty-four studies (954 fetuses) were included. In 53.8% (95% CI, 46.0-61.5%) of cases for which resolution of the cyst was evaluated (784 fetuses), the cyst regressed either during pregnancy or after birth. The likelihood of resolution was significantly lower in complex vs simple cysts (odds ratio (OR), 0.15 (95% CI, 0.10-0.23)) and in cysts measuring ≥ 40 mm vs < 40 mm (OR, 0.03 (95% CI, 0.01-0.06)). Change in ultrasound pattern of the cyst was associated with an increased risk of ovarian loss (surgical removal or autoamputation) (pooled proportion, 57.7% (95% CI, 42.9-71.8%)). The risk of ovarian torsion was significantly higher for cysts measuring ≥ 40 mm compared with < 40 mm (OR, 30.8 (95% CI, 8.6-110.0)). The likelihood of having postnatal surgery was higher in patients with cysts ≥ 40 mm compared with < 40 mm (OR, 64.4 (95% CI, 23.6-175.0)) and in complex compared with simple cysts, irrespective of cyst size (OR, 14.6 (95% CI, 8.5-24.8)). In cases undergoing prenatal aspiration of the cyst, rate of recurrence was 37.9% (95% CI, 14.8-64.3%), ovarian torsion and intracystic hemorrhage were diagnosed after birth in 10.8% (95% CI, 4.4-19.7%) and 12.8% (95% CI, 3.8-26.0%), respectively, and 21.8% (95% CI, 0.9-40.0%) had surgery after birth.

CONCLUSION

Size and ultrasound appearance are the major determinants of perinatal outcome in fetuses with ovarian cysts. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Systematic review and meta-analysis of persistent left superior vena cava on prenatal ultrasound: associated anomalies, diagnostic accuracy and postnatal outcome

OBJECTIVES

To quantify the prevalence of chromosomal anomalies in fetuses with persistent left superior vena cava (PLSVC), assess the strength of the association between PLSVC and coarctation of the aorta and ascertain the diagnostic accuracy of antenatal ultrasound in correctly identifying isolated cases of PLSVC.

METHODS

MEDLINE, EMBASE, CINHAL and the Cochrane databases were searched from the year 2000 onwards using combinations of keywords 'left superior vena cava' and 'outcome'. Two authors reviewed all abstracts independently. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale for cohort studies. The rates of the following outcomes were analyzed: chromosomal abnormalities; associated intracardiac anomalies (ICAs) and extracardiac anomalies (ECAs) diagnosed prenatally; additional ICAs and ECAs detected only at postnatal imaging or clinical evaluation but missed at prenatal imaging; and association of PLSVC and coarctation of the aorta. Meta-analyses of proportions were used to combine data.

RESULTS

In total, 2708 articles were identified and 13 (n = 501) were included in the systematic review. Associated ICAs and ECAs were detected at the prenatal ultrasound examination or at a follow-up assessment in 60.7% (95% CI, 44.2-75.9%) and 37.8% (95% CI, 31.0-44.8%) of cases, respectively. Chromosomal anomalies occurred in 12.5% (95% CI, 9.0-16.4%) of cases in the overall population of fetuses with PLSVC and in 7.0% (95% CI, 2.7-13.0%) of isolated cases. Additional ICAs and ECAs were detected only after birth and missed at ultrasound in 2.4% (95% CI, 0.5-5.8%) and 6.7% (95% CI, 2.2-13.2%) of cases, respectively. Coarctation of the aorta was associated with isolated PLSVC in 21.3% (95% CI, 13.6-30.3%) of cases.

CONCLUSIONS

PLSVC is commonly associated with ICAs, ECAs and chromosomal anomalies. Fetuses with isolated PLSVC should be followed up throughout pregnancy in order to rule out coarctation of the aorta. As most of the data in this review were derived from high-risk pregnancies, the rate of associated abnormalities is likely to be higher than that in the general population of fetuses with PLSVC, for which more data are needed. Revisión sistemática y metaanálisis de la persistencia de la vena cava superior izquierda en la ecografía prenatal: anomalías asociadas, precisión del diagnóstico y resultado postnatal RESUMEN OBJETIVOS: Cuantificar la prevalencia de anomalías cromosómicas en fetos con vena cava superior izquierda persistente (VCSIP), evaluar la solidez de la asociación entre la VCSIP y la coartación aórtica, y determinar la precisión del diagnóstico de la ecografía prenatal como método para identificar correctamente casos aislados de VCSIP. MÉTODOS: Se buscó en las bases de datos de MEDLINE, EMBASE, CINHAL y Cochrane artículos publicados desde el año 2000 en adelante, usando combinaciones de las palabras clave "vena cava superior izquierda" y "resultado". Dos de los autores revisaron de forma independiente todos los resúmenes encontrados. La evaluación de calidad de los estudios incluidos se realizó mediante la escala Newcastle-Ottawa para estudios de cohortes. Se analizaron las tasas de los siguientes resultados: anomalías cromosómicas; anomalías intracardíacas (AIC) y anomalías extracardíacas (AEC) asociadas diagnosticadas prenatalmente; AIC y AEC adicionales detectadas sólo en ecografías postnatales o mediante evaluación clínica, pero no observadas en ecografías prenatales; y la asociación entre la VCSIP y la coartación aórtica. Se utilizó un meta-análisis de proporciones para combinar los datos.

RESULTADOS

En total, se identificaron 2708 artículos y se incluyeron 13 (n = 501) en la revisión sistemática. En la ecografía prenatal o en una revisión de seguimiento se detectaron AIC y AEC asociadas en el 60,7% (IC 95%, 44,2-75,9%) y el 37,8% (IC 95%, 31,0-44,8%) de los casos, respectivamente. Se produjeron anomalías cromosómicas en el 12,5% (IC 95%, 9,0-16,4%) de los casos en la población general de fetos con VCSIP y en el 7,0% (IC 95%, 2,7-13,0%) de casos aislados. Las AIC y AEC adicionales sólo se detectaron después del nacimiento y en el 6,7% (IC 95%, 2,2-13,2%) de los casos, respectivamente. La coartación aórtica se encontró asociada con la VCSIP aislada en un 21,3% (IC 95%, 13,6-30,3%) de los casos.

CONCLUSIONES

La VCSIP está comúnmente asociada a AIC, AEC y anomalías cromosómicas. Los fetos con VCSIP aislada deben ser objeto de seguimiento durante todo el embarazo, con el fin de descartar la coartación aórtica. Como la mayoría de los datos de esta revisión proceden de embarazos de alto riesgo, es probable que la tasa de anomalías asociadas sea más alta que la de la población general de fetos con VCSIP, por lo que se necesitan más datos.

Assay for drug discovery: Synthesis and testing of nitrocefin analogues for use as β-lactamase substrates

We report on the synthesis of three nitrocefin analogues and their evaluation as substrates for the detection of β-lactamase activity. These compounds are hydrolyzed by all four Ambler classes of β-lactamases. Kinetic parameters were determined with eight different β-lactamases, including VIM-2, NDM-1, KPC-2, and SPM-1. The compounds do not inhibit the growth of clinically important antibiotic-resistant gram-negative bacteria in vitro. These chromogenic compounds have a distinct absorbance spectrum and turn purple when hydrolyzed by β-lactamases. One of these compounds, UW154, is easier to synthesize from commercial starting materials than nitrocefin and should be significantly less expensive to produce.

Clinical outcomes of diabetic patients at a student-run free clinic project

OBJECTIVES

Our objective was to determine if the quality of care of diabetic patients at a Student-Run Free Clinic Project (SRFCP) meets the standard of care, is comparable with other published outcomes, and whether pertinent diabetic clinical indicators improve over time.

METHODS

The authors conducted a retrospective chart review of diabetic patients at three University of California-San Diego (UCSD) SRFCP sites from December 1, 2008 to December 1, 2009 (n=182), calculated the percentage who received recommended screening tests, percent at goal, and compared these to published outcomes using Fisher's exact tests. Baseline measures were compared to most recent values using paired t tests.

RESULTS

The percentage of patients who received recommended screening tests (process measures) was blood pressure (BP) 100%, HbA1c 99.5%, creatinine 99.5%, LDL 93%, HDL and triglycerides 88%, microalbumin/creatinine ratio 80%, and ophthalmology exam 32%. Intermediate outcomes included: 70% of patients were at LDL goal <100, 70% had microalbumin/creatinine ratio <30, 61% of males were at HDL goal %gt;40, 47% of females at HDL goal>50, 52% with triglycerides <150, 45% had BP <130/80, and 30% of patients had HbA1c <7. Mean HbA1c, LDL, HDL, triglycerides and blood pressure improved significantly over time.

CONCLUSIONS

Diabetic patients at UCSD SRFCP reached goals for both process measures and intermediate outcomes at rates that meet or exceed published outcomes of insured and uninsured diabetics on nearly all measures, with the exception of ophthalmology screening. Glycemic control, cholesterol levels, and blood pressure improved significantly during care at the UCSD SRFCP.

Structural studies of the final enzyme in the alpha-aminoadipate pathway-saccharopine dehydrogenase from Saccharomyces cerevisiae

The 1.64 A structure of the apoenzyme form of saccharopine dehydrogenase (SDH) from Saccharomyces cerevisiae shows the enzyme to be composed of two domains with similar dinucleotide binding folds with a deep cleft at the interface. The structure reveals homology to alanine dehydrogenase, despite low primary sequence similarity. A model of the ternary complex of SDH, NAD, and saccharopine identifies residues Lys77 and Glu122 as potentially important for substrate binding and/or catalysis, consistent with a proton shuttle mechanism. Furthermore, the model suggests that a conformational change is required for catalysis and that residues Lys99 and Asp281 may be instrumental in mediating this change. Analysis of the crystal structure in the context of other homologous enzymes from pathogenic fungi and human sources sheds light into the suitability of SDH as a target for antimicrobial drug development.

N-arylsulfonyl hydrazones as inhibitors of IMP-1 metallo-beta-lactamase

Members of a family of N-arylsulfonyl hydrazones have been identified as novel inhibitors of IMP-1, a metallo-beta-lactamase of increasing prevalence. Structure-activity relationship studies have indicated a requirement for bulky aromatic substituents on each side of the sulfonyl hydrazone backbone for these compounds to serve as efficient inhibitors of IMP-1. Molecular modeling has provided insight into the structural basis for the anti-metallo-beta-lactamase activity exhibited by this class of compounds.

Characterization of function and activity of domains A, B and C of xylanase C from Fibrobacter succinogenes S85

Xylanase C from the ruminant bacterium Fibrobacter succinogenes is comprised of two catalytic domains, A and B, and a third domain, C, of unknown function. The DNA coding for domains A and B of xylanase C were separately cloned and expressed in Escherichia coli as fusion proteins with glutathione-S:-transferase. The fusion proteins were isolated by affinity chromatography on glutathione-Sepharose 4B, cleaved with thrombin and the released xylanase C catalytic domains A and B were purified to apparent homogeneity by anion-exchange chromatography on Mono Q. Electrospray mass spectrometry provided a molecular mass of 27 818 Da (expected, 27 820 Da) for domain B. The pH and temperature optima for activity of domain B on oat spelt xylan were 5.0 and 52 degrees C, respectively. A kinetic analysis of the activity of the catalytic domain A on oat spelt xylan, birch wood xylan and xylooligomers at pH 6.5 and 37 degrees C provided data significantly different to those obtained previously with a protease-derived form of the enzyme [Zhu et al. (1994) J. Bacteriol. 176, 3885-3894]. The isolated domain A was more active on barley-glucan than the protease-derived form and its affinity for birch wood xylan was enhanced resulting in greater overall catalytic efficiency as reflected by k(cat)/K:(M) values. Likewise, significant differences in the Michaelis-Menten parameters K:(M), k(cat) and k(cat)/K:(M) were obtained with domain B compared with values previously reported with this domain attached to domain C. In general, the presence of domain C appeared to decrease the overall efficiency of domain B 7- and 36-fold with birch wood xylan and xylopentaose as substrates, respectively, as reflected by values of k(cat)/K:(M). The removal of domain C also affected the mode of action of domain B such that it more closely resembled that of catalytic domain A. However, no change in either pH and temperature optima or stability were found with domain B compared with the combined domains B and C. The function of domain C remains unknown, but hydrophobic cluster analysis indicated that it may belong to a class of dockerin domains involved in the protein-protein interactions of cellulolytic and xylanolytic complexes.

The role of tryptophan residues in substrate binding to catalytic domains A and B of xylanase C from Fibrobacter succinogenes S85

Oxidation of the isolated catalytic domain B of xylanase C (XynC-B) from Fibrobacter succinogenes with N-bromosuccinimide (NBS) resulted in the modification of five of the seven Trp residues present in the enzyme. Hydrolytic activity of the enzyme was rapidly lost upon initiation of oxidation as a molar ratio of about two NBS molecules per molar equivalent of protein was sufficient to cause 50% inhibition of enzyme activity, and the addition of five molar equivalents of NBS resulted in less than 10% activity. Pre-incubation of XynC-B with the competitive inhibitor D-xylose resulted in the apparent protection of two Trp residues from oxidation. Xylose protection of the enzyme also resulted in a maintenance of activity, with 60% activity still evident after addition of 8-9 molar equivalents of NBS. This protection from inactivation was enhanced by the inclusion of xylohexaose in reaction mixtures. Under these conditions, however, a further Trp residue was protected from NBS oxidation. The three protected Trp residues were identified as Trp135, Trp161 and Trp202 by differential labelling and peptide mapping of NBS-oxidized preparations of the xylanase employing a combination of electrospray mass spectroscopic analysis and N-terminal sequencing. By analogy to the known structures of the family 11 xylanases, the fully conserved Trp202 residue is located on the only alpha-helix present in the enzymes, at the interface between it and the back of the beta-sheet which forms the active site cleft. Trp135 represents a highly conserved aromatic residue in family 11, but it is replaced with Thr in domain A of F. succinogenes xylanase C. To investigate the role of Trp135 in conferring the different activity profile of domain B relative to domain A, the Trp135Thr and Trp135Ala derivatives of domain B were prepared by site-directed mutagenesis. However, the kinetic parameters of the two domain B derivatives were not significantly different compared to the wild-type enzyme as reflected by K(M) and k(cat) values and product distribution profiles. Similar results were obtained with the Trp161Ala derivative of domain B, indicating that these two residues do not directly participate in the binding of substrate but likely form the foundation for binding subsite 2.

Lysine: N6-hydroxylase: stability and interaction with ligands

Recombinant lysine:N6-hydroxylase, rIucD, which is isolated as an apoenzyme, requires FAD and NADPH for its catalytic function. rIucD preparations have been found to undergo time-dependent loss in monooxygenase function due to aggregation from the initial tetrameric state to a polytetrameric form(s), a process which is reversible by treatment with thiols. Ligand-induced conformational changes in rIucD were assessed by monitoring its CD spectra, DSC profile, and susceptibility to both endo- as well as exopeptidases. The first two methods indicated the absence of any significant conformational change in rIucD, while the last approach revealed that FAD, and its analog ADP, can protect the protein from the deleterious action of proteases. NADPH was partially effective and L-lysine was ineffective in this regard. Deletion of the C-terminal segment, either by treatment with carboxypeptidase Y or by mutagenesis of iucD, results in the loss of rIucD's monooxygenase activity. These findings demonstrate the crucial role of the C-terminal segment in maintaining rIucD in its native conformation.

Suppression of protein synthesis in brain during hibernation involves inhibition of protein initiation and elongation

Protein synthesis (PS) has been considered essential to sustain mammalian life, yet was found to be virtually arrested for weeks in brain and other organs of the hibernating ground squirrel, Spermophilus tridecemlineatus. PS, in vivo, was below the limit of autoradiographic detection in brain sections and, in brain extracts, was determined to be 0.04% of the average rate from active squirrels. Further, it was reduced 3-fold in cell-free extracts from hibernating brain at 37 degreesC, eliminating hypothermia as the only cause for protein synthesis inhibition (active, 0.47 +/- 0.08 pmol/mg protein per min; hibernator, 0.16 +/- 0.05 pmol/mg protein per min, P < 0.001). PS suppression involved blocks of initiation and elongation, and its onset coincided with the early transition phase into hibernation. An increased monosome peak with moderate ribosomal disaggregation in polysome profiles and the greatly increased phosphorylation of eIF2alpha are both consistent with an initiation block in hibernators. The elongation block was demonstrated by a 3-fold increase in ribosomal mean transit times in cell-free extracts from hibernators (active, 2.4 +/- 0.7 min; hibernator, 7.1 +/- 1.4 min, P < 0.001). No abnormalities of ribosomal function or mRNA levels were detected. These findings implicate suppression of PS as a component of the regulated shutdown of cellular function that permits hibernating ground squirrels to tolerate "trickle" blood flow and reduced substrate and oxygen availability. Further study of the factors that control these phenomena may lead to identification of the molecular mechanisms that regulate this state.

Effect of selective cysteine --> alanine replacements on the catalytic functions of lysine: N6-hydroxylase

Recombinant lysine: N6-hydroxylase, rIucD, catalyzes the conversion of L-lysine to its N6-hydroxy derivative. Re-examination of the nucleotide sequence of iucD, the gene encoding for the enzyme, has revealed a few discrepancies in the data documented in literature and the corrected version is presented. The revised nucleotide sequence predicts the presence of five cysteine residues in the primary structure of IucD. Two of these residues, cysteine 51 and cysteine 158 are alkylatable by iodoacetate in the native conformation of the protein resulting in a loss of monooxygenase activity while their replacement with alanine has no such adverse effect. Site directed mutagenesis studies have enabled an assessment of the reactivity of these cysteine residue(s) towards thiol modifying agents.