Clinical Reasoning: A 24-Year-Old Pregnant Woman With Headache and Behavioral Change Progressing to Coma

The broad differential diagnosis associated with progressive subacute encephalopathy can be intimidating, especially in a young, pregnant woman. In this case, a 24-year-old woman at 21 weeks of gestation presented with persistent, drug-resistant fronto-parietal headache, with subsequent progressive development of psychomotor lentification and inappropriate behavior. Physical examination was normal, as were routine laboratory parameters and CT findings, and these symptoms were initially interpreted in the context of chronic depression. Later, the patient developed generalized dystonia and fever, with rapid clinical deterioration, depression of consciousness and, eventually, progression to coma. This case emphasizes the complexity and challenges involved in the diagnostic approach to a patient with progressive subacute encephalopathy framed by worsening CNS symptoms. It highlights the clinical considerations and complementary investigation of various etiologies, in a step-by-step approach, ultimately leading to the final diagnosis. Early recognition and appropriate treatment of these conditions can lead to more favorable outcomes, particularly in gestating patients, where prompt intervention is crucial, and where critical decisions may have to be made regarding pregnancy and the safety of treatment options.

Revisiting predictions of movie economic success: random Forest applied to profits

Previous studies have employed machine learning tools to classify films according to success to guide a reduction in the degree of uncertainty of film production. We revisited the literature to contribute to three relevant issues in classifying films according to economic success. First, we explored the differences between the results of the shortest or longest samples in terms of time to study possible changes in patterns of consumption mainly due to technological changes and between total and wide-released films. Second, we used profits free of price inflation as measures of economic success instead of the usual box office nominal revenues. Third, we employed a smaller set of features, only the ones available at the time of production, to help producers maneuver contingencies since little or nothing can be done by the time a film is in the theaters. We followed the literature to choose the classifiers - Random Forest, Support Vector Machine, and Neural Network - and designed sub-datasets to model and compare the performance of our results. Our dataset includes all films with budgets disclosed at the Box Office Mojo website, resulting in 3167 movies released at theaters worldwide between 1980 and 2019. The Random Forest results outperform previous similar studies with different sampling in time, including results for a less usual larger sample, with the best data sample about 97% both in accuracy and F1-score.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11042-023-15169-4.

3D Biocomposites Comprising Marine Collagen and Silica-Based Materials Inspired on the Composition of Marine Sponge Skeletons Envisaging Bone Tissue Regeneration

Ocean resources are a priceless repository of unique species and bioactive compounds with denouement properties that can be used in the fabrication of advanced biomaterials as new templates for supporting the cell culture envisaging tissue engineering approaches. The collagen of marine origin can be sustainably isolated from the underrated fish processing industry by-products, while silica and related materials can be found in the spicules of marine sponges and diatoms frustules. Aiming to address the potential of biomaterials composed from marine collagen and silica-based materials in the context of bone regeneration, four different 3D porous structure formulations (COL, COL:BG, COL:D.E, and COL:BS) were fabricated by freeze-drying. The skins of Atlantic cod (Gadus morhua) were used as raw materials for the collagen (COL) isolation, which was successfully characterized by SDS-PAGE, FTIR, CD, and amino acid analyses, and identified as a type I collagen, produced with a 1.5% yield and a preserved characteristic triple helix conformation. Bioactive glass 45S5 bioglass® (BG), diatomaceous earth (D.E.) powder, and biosilica (BS) isolated from the Axinella infundibuliformis sponge were chosen as silica-based materials, which were obtained as microparticles and characterized by distinct morphological features. The biomaterials revealed microporous structures, showing a porosity higher than 85%, a mean pore size range of 138-315 μm depending on their composition, with 70% interconnectivity which can be favorable for cell migration and ensure the needed nutrient supply. In vitro, biological assays were conducted by culturing L929 fibroblast-like cells, which confirmed not only the non-toxic nature of the developed biomaterials but also their capability to support cell adhesion and proliferation, particularly the COL:BS biomaterials, as observed by calcein-AM staining upon seven days of culture. Moreover, phalloidin and DAPI staining revealed well-spread cells, populating the entire construct. This study established marine collagen/silica biocomposites as potential scaffolds for tissue engineering, setting the basis for future studies, particularly envisaging the regeneration of non-load-bearing bone tissues.

The Factor Structure of the Portuguese Version of the Personality Inventory for DSM-5 (PID-5)

Introduction

The DSM-5 Section III proposes a dimensional-categorical model of conceptualizing personality and its disorders, which includes assessment of impairments in personality functioning (criterion A) and maladaptive personality traits (criterion B). The Personality Inventory for DSM-5 (PID-5) is a self-report, composed of 220 items, organized into 25 facets nested in five domains of personality differences, and was developed to operationalize criterion B.

Objectives

This study explores the factor structure of the Portuguese adaptation of the PID-5.

Aims

The five-factor structure that has emerged in previous studies with the PID-5 (cf. Krueger & Markon) is expected to be replicated in the current study.

Methods

Exploratory factor analyses with varimax oblique rotation were conducted on a sample of Portuguese adults from the general population (n = 379, Mage = 31.49, SD = 14.16, 25.3% males, 74.7% females).

Results

A six factor structure was retained in which the first 5 factors resemble the PID-5 domains. The model showed good fit indices (KMO = 0.897). The total explained variance was 68.25%. All the facets but four had primary loadings on the expected factor.

Conclusions

The similarity of results across studies and nationalities contributes to the validation of the Portuguese translation of the PID-5 and highlights the structural resemblance among the DSM-5 model and the five factor model (FFM) and the personality psychopathology-five model (PSY-5), drawing attention to the relevance of these models for the diagnosis of Personality Disorders.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Evaluation of multi-class support-vector machines strategies and kernel adjustment levels in hand posture recognition by analyzing sEMG signals acquired from a wearable device

One-vs-One (OVO) and One-vs-All (OVA) are decomposition methods for multi-class strategies used to allow binary Support-Vector Machines (SVM) to transform a given k-class problem into pairwise small problems. In this context, the present work proposes the analysis of these two decomposition methods applied to the hand posture recognition problem in which the sEMG data of eight participants were collected by means of an 8-channel armband bracelet located on the forearm. Linear, Polynomial and Radial Basis Function kernels functions and its adjustments level were implemented combined to the strategies OVO and OVA to compare the performance of the SVM when mapping posture data into the classification spaces spanned by the studied kernels. Acquired sEMG signals were segmented considering 0.16 s e 0.32 s time windows. Root Mean Square (RMS) feature was extracted from each time window of each posture and used for SVM training. The present work focused in investigating the relationship between the multi-class strategies combined to kernels adjustments levels and SVM classification performance. Promising results were observed using OVA strategy which presents a reduced number of binary SVM implementation achieved a mean accuracy of 97.63%.

OBP fused with cell-penetrating peptides promotes liposomal transduction

Cell-penetrating peptides (CPPs) have been applied as novel transport systems with the ability to facilitate the delivery of peptides, proteins, and oligonucleotides into cells. Herein, we designed different fusion proteins composed by pig odorant binding protein (OBP-I) and three CPPs, namely Tat, pVEC and Pep-1. A new methodology using liposomes as reservoirs and OBP:CPPs as carriers was developed as an advanced system to capture odorant molecules. 1-aminoanthracene (1-AMA) was used as a model molecule to evaluate the transduction ability of OBP:CPPs into the reservoirs. The transduction efficiency was dependent on the initial capacity of OBP:CPPs to bind 1-AMA and on the penetration of liposomes promoted by the CPPs. An encapsulation efficiency of 42% was obtained with OBP:Tat fusion protein. The presence of Tat peptide increased the 1-AMA transduction of 1.3 and 2.5 fold compared with Pep-1 and pVEC, respectively. This work expands the application of OBPs and CPPs on the design of promising capture and delivery systems for textile and cosmetic applications.

Mitochondrial DNA analysis of Tunisians reveals a mosaic genetic structure with recent population expansion

Tunisia is a country of great interest for human population genetics due to its strategic geographic position and rich human settlement history. These factors significantly contributed to the genetic makeup of present-day Tunisians harbouring components of diverse geographic origins. Here, we investigated the genetic structure of Tunisians by performing a mitochondrial DNA (mtDNA) comparison of 15 Tunisian population groups, in order to explore their complex genetic landscape. All Tunisian data were also analysed against 40 worldwide populations. Statistical results (Tajima's D and Fu's F_S tests) suggested recent population expansion for the majority of studied populations, as well as showed (AMOVA test) that all populations were significantly different from each other, which is evidence of population structure even if it is not guided by geographic and ethnic effects. Gene flow analysis revealed the assignment of Tunisians to multiple ancestries, which agrees with their genetic heterogeneity. The resulting picture for the mtDNA pool confirms the evidence of a recent expansion of the Tunisian population and is in accordance with a mosaic structure, composed by North African, Middle Easterner, European and Sub-Saharan lineages, resulting from a complex settlement history.

Therapy-Induced Cellular Senescence Induces Epithelial-to-Mesenchymal Transition and Increases Invasiveness in Rectal Cancer

INTRODUCTION

DNA damaging agents and ionizing radiation used in the therapy of human cancers can induce senescence of cancer cells. Senescent cells exhibit a secretory phenotype (senescence-associated secretome [SAS]) that can affect cancer cell behavior and, eventually, clinical prognosis. We assessed the effects of the SAS on the induction of epithelial-to-mesenchymal transition (EMT) in vitro and in clinical samples from patients with rectal cancer who had undergone neoadjuvant chemoradiotherapy (CRT).

MATERIALS AND METHODS

Colorectal cancer cells (HCT 116) were induced into senescence by exposure to either 5-fluorouracil (5-FU) or doxorubicin. The senescent state was confirmed by staining for senescence-associated β-galactosidase (SA-β-Gal). The paracrine effects of SASs were assessed on proliferating HCT 116 cells. The quantified parameters were cell proliferation, invasive capacity, and induction of EMT. Senescence and EMT in clinical samples were assessed by the expression levels (reverse transcriptase-quantitative polymerase chain reaction) of genes related to senescence and EMT after laser-assisted microdissection of cancer cell clusters that stained either positive or negative for SA-β-Gal.

RESULTS

We have shown that cultured colon cancer cells induced into senescence by exposure to 5-FU exhibit a SAS capable of paracrine induction of EMT in colon and rectal cancer cell lines and increased cell invasion in vitro. Using laser-assisted microdissection, we found that in rectal cancer samples from patients treated with neoadjuvant CRT, tumor cell niches enriched for senescent cells bookmark regions of increased mRNA expression levels of EMT-related proteins (Slug, Snail, vimentin) compared with the nearby senescent-null tumor cell niches.

CONCLUSION

We have provided, first-hand, strongly suggestive evidence that senescent cancer cells emerging in the context of neoadjuvant CRT for rectal cancer influenced the tumor microenvironment by promoting EMT by way of short-range interactions.

Prognostic Factors after Liver Resection for Colorectal Liver Metastasis

INTRODUCTION

Surgery is the only potentially curative treatment for patients with colorectal liver metastases, resulting in 5-year survival rates of 36 -€“ 58. Although many studies have been performed to determine prognostic factors for tumor recurrence and survival after resection of colorectal liver metastases, there are few prognostic scoring systems stratifying patients undergoing surgery for colorectal liver metastases into risk group models.

OBJECTIVES

To identify, evaluate and compare the existing prognostic scores for survival after surgery for resection of colorectal liver metastases.

MATERIAL AND METHODS

Electronic search in PubMed, Cochrane and Embase from 1990 to 2013 using the terms '€˜hepatic resection', '€˜colorectal cancer'€™, 'liver metastasis', '€˜hepatectomy', '€˜prognostic'€™, and '€˜score'€˜. Only studies proposing a prognostic model or risk stratification based on clinical and/or pathological variables were included.

RESULTS

From 1996 to June 2013, 19 scoring systems were identified, including one nomogram. Thirty prognostic factors were identified although none of the factors was common to all prognostic models. The 4 factors most often included were: number of liver metastases, regional lymph node metastization of primary tumor, preoperative CEA level and maximum size of metastases. The median study sample size was 305 patients (81-1 568 patients) and median follow-up was 33 months (16-54 months). All studies were retrospective and used the Cox proportional hazards model for multi-variable analysis.

CONCLUSION

Several factors have been constantly reported as having prognostic value after liver resection of colorectal livermetastases, although there is no consensus on the ideal scoring system.

Observation of Efimov resonances in a mixture with extreme mass imbalance

We observe two consecutive heteronuclear Efimov resonances in an ultracold Li-Cs mixture by measuring three-body loss coefficients as a function of magnetic field near a Feshbach resonance. The first resonance is detected at a scattering length of a_((0))=-320(10)a_((0)), corresponding to ∼7(∼3) times the Li-Cs (Cs-Cs) van der Waals range. The second resonance appears at 5.8(1.0)a_((0)), close to the unitarity-limited regime at the sample temperature of 450 nK. Indication of a third resonance is found in the atom loss spectra. The scaling of the resonance positions is close to the predicted universal scaling value of 4.9 for zero temperature. Deviations from universality might be caused by finite-range and temperature effects, as well as magnetic field-dependent Cs-Cs interactions.

Metadherin expression and lung relapse in patients with colorectal carcinoma

Colorectal cancer (CRC) is the third most common malignant disease in men and the second in women worldwide. CRC relapse occurs mostly in liver and lungs, decreasing the 5-year survival to 6 %. Metadherin (MTDH) is overexpressed in several types of cancer, has been implicated in proliferation, invasion, metastasis, angiogenesis, and chemoresistance, and is a factor of poor prognosis in CRC. In this work we addressed the prognostic significance of MTDH expression in CRC progression to the lungs. We found that MTDH gene was more frequently amplified (copy number >1.8) in patients with CRC and relapse to the lung, when compared to patients without lung metastases (17.4 vs 100 %; p < 0.001). We observed a correlation between MTDH gene copy number and MTDH expression by IHC (p = 0.0001). Next we also analyzed MTDH expression by IHC in samples from 85 patients diagnosed with CRC, stage II or III, M0, with at least 3 years of follow-up. Kaplan-Meier survival analysis showed that lung relapse-free survival (HR 5.29, 95 % CI 1.90-14.77, p = 0.0004), liver relapse-free survival (HR 8.59, 95 % CI 0.99-74.18, p = 0.003), relapse-free survival (HR 4.85, 95 % CI 1.88-12.45, p = 0.0003) and overall survival (HR 3.75, 95 % CI 1.15-12.18, p = 0.018) were significantly lower in the group with high MTDH expression. Multivariate analysis showed that high MTDH expression was an independent factor for all outcomes. This study demonstrates that high MTDH expression is a biomarker of relapse in CRC, including lung-specific relapse. Determination of MTDH expression in primary CRC may be useful in the earlier detection of lung metastases in patients with high expression and increased risk.

Immobilization of bioactive factor-loaded liposomes on the surface of electrospun nanofibers targeting tissue engineering

Dexamethasone-loaded liposomes immobilized at the surface of electrospun polycaprolactone nanofiber meshes successfully promoted the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells.

RANKL enhances the effect of an antagonist of inhibitor of apoptosis proteins (cIAPs) in RANK-positive breast cancer cells

Objective

Between 65% and 75% of patients with metastatic breast cancer will have decreased 5-year survival and increased morbidity due to cancer relapse in bone. At this stage of disease treatment is palliative, but tumor-targeted compounds could add to the benefits of anti-resorptive agents, improving clinical outcome. Inhibitor-of-apoptosis proteins (IAPs) are overexpressed in many tumors and second mitochondria-derived activator of caspases (Smac) mimetics have been designed to antagonize IAPs. In this work we explored the use of AT-406, a Smac mimetic, to target the tumor compartment of bone metastases.

Methods

Effect of AT-406 on cancer cells apoptosis, expression of IAPs and osteogenic potential was addressed in vitro using the RANK-positive MDA-MB-231 breast cancer cell line. Effect of AT-406 on osteoclastogenesis was determined by inducing the differentiation of the RAW 264.7 mouse monocytic cell line. Osteoclastogenesis was measured by TRAP staining and TRACP 5b quantification.

Results

AT-406 increased apoptosis in MDA-MB-231 breast cancer cells in vitro, and activation of RANK-pathway improved this effect. RANKL stimuli induced a strong increase in c-IAP2. AT-406 increased osteoclast differentiation and activity, by up-regulating the osteogenic transcription factor Nfatc1, but also increased the apoptosis of mature osteoclasts in the absence of RANKL.

Conclusions

Our results indicate that despite the anti-tumoral effect of AT-406, its use in the context of bone metastatic disease needs to be carefully monitored for the induction of increased bone resorption. We also hypothesize that the combination of AT-406 with anti-RANKL directed therapies could have a beneficial effect, especially in RANK-positive tumors.

RANKL/RANK/MMP-1 molecular triad contributes to the metastatic phenotype of breast and prostate cancer cells in vitro

The osteolytic nature of bone metastasis results from a tumor-driven increased bone resorption. Bone remodeling is orchestrated by the molecular triad RANK-RANKL-OPG. This process is dysregulated in bone metastases, mostly via induction of RANKL by tumor-derived factors. These factors increase expression of RANKL, which induce osteoclast formation, function, and survival, thereby increasing bone resorption. RANK is unexpectedly expressed by cancer cells, and the activation of RANKL-RANK pathway correlates with an increased invasive phenotype. To investigate the interaction between RANK expression in human breast and prostate cancer cells and their pro-metastatic phenotype we analyzed the activation of RANKL-RANK pathway and its effects on cell migration, invasion, gene expression in vitro, and osteolysis-inducing ability in vivo. RANKL activates kinase signaling pathways, stimulates cell migration, increases cell invasion, and up-regulates MMP-1 expression. In vivo, MMP-1 knockdown resulted in smaller x-ray osteolytic lesions and osteoclastogenesis, and decreased tumor burden. Therefore, RANKL inhibition in bone metastatic disease may decrease the levels of the osteoclastogenesis inducer MMP-1, contributing to a better clinical outcome.

MTA1 promotes STAT3 transcription and pulmonary metastasis in breast cancer

Overexpression of the prometastatic chromatin modifier protein metastasis tumor antigen 1 (MTA1) in human cancer contributes to tumor aggressiveness, but the role of endogenous MTA1 in cancer has not been explored. Here, we report the effects of selective genetic depletion of MTA1 in a physiologically relevant spontaneous mouse model of breast cancer pulmonary metastasis. We found that MTA1 acts as a mandatory modifier of breast-to-lung metastasis without effects on primary tumor formation. The underlying mechanism involved MTA1-dependent stimulation of STAT3 transcription through action on the MTA1/STAT3/Pol II coactivator complex, and, in turn, on the expression and functions of STAT3 target genes including Twist1. Accordingly, we documented a positive correlation between levels of MTA1 and STAT3 in publicly available breast cancer data sets. Together, our findings reveal an essential modifying role of the physiologic level of MTA1 in supporting pulmonary metastasis of breast cancer.

Description of macrolide-resistant and potential virulent clones of Streptococcus pyogenes causing asymptomatic colonization during 2000-2006 in the Lisbon area

The asymptomatic oropharyngeal colonization rate by Streptococcus pyogenes was 10.7% in children (901 among 8,405 children 0-16 years old) and 3.3% in adults (37 among 1,126 households of children) in the Lisbon area during 2000-2006. Macrolide-resistant S. pyogenes from children (n = 149) was variable with time: 9.8-10.7% in 2000-2002, 28.1% in 2003, 19.6-2.7% in 2004-2005 and 14.6% in 2006. Eight lineages (97.3% of isolates) were identified based on at least 80% similarity of PFGE patterns, T types, emm types and multilocus sequence types (ST). The elevated frequency of macrolide resistance was associated with M phenotype lineages I (emm12/ST36) and V (emm4, emm75/ST39 and a novel emmstMrp6 type) and with one cMLS(B) lineage IV (emm28/ST52) known to be associated with upper respiratory tract and invasive infections. Significant associations (p < 0.05) between emm type/virulence genotype were found, such as emm1/speA (+) ssa (-), emm4/ssa (+) prtF1 (+), emm12/speA (-) ssa (-). The high prevalence (>20%) of speC, prtF1 or ssa was probably caused either by clonal dissemination (speC), or to horizontal gene transfer events (prtF1 and ssa). This report contributes to a better understanding of the molecular epidemiology and evolution of macrolide-resistant S. pyogenes causing symptom-free oropharyngeal colonization. These colonizing strains carry macrolide resistance and virulence genes capable of being transferred to other bacterial species sharing the same niche.

A crescent-shaped ALIX dimer targets ESCRT-III CHMP4 filaments

ALIX recruits ESCRT-III CHMP4 and is involved in membrane remodeling during endosomal receptor sorting, budding of some enveloped viruses, and cytokinesis. We show that ALIX dimerizes via the middle domain (ALIX(-V)) in solution. Structural modeling based on small angle X-ray scattering (SAXS) data reveals an elongated crescent-shaped conformation for dimeric ALIX lacking the proline-rich domain (ALIX(BRO1-V)). Mutations at the dimerization interface prevent dimerization and induce an open elongated monomeric conformation of ALIX(-V) as determined by SAXS modeling. ALIX dimerizes in vivo and dimeric ALIX colocalizes with CHMP4B upon coexpression. We show further that ALIX dimerization affects HIV-1 budding. C-terminally truncated activated CHMP4B retaining the ALIX binding site forms linear, circular, and helical filaments in vitro, which can be bridged by ALIX. Our data suggest that dimeric ALIX represents the active form that interacts with ESCRT-III CHMP4 polymers and functions as a scaffolding protein during membrane remodeling processes.

Helical structures of ESCRT-III are disassembled by VPS4

During intracellular membrane trafficking and remodeling, protein complexes known as the ESCRTs (endosomal sorting complexes required for transport) interact with membranes and are required for budding processes directed away from the cytosol, including the budding of intralumenal vesicles to form multivesicular bodies; for the budding of some enveloped viruses; and for daughter cell scission in cytokinesis. We found that the ESCRT-III proteins CHMP2A and CHMP3 (charged multivesicular body proteins 2A and 3) could assemble in vitro into helical tubular structures that expose their membrane interaction sites on the outside of the tubule, whereas the AAA-type adenosine triphosphatase VPS4 could bind on the inside of the tubule and disassemble the tubes upon adenosine triphosphate hydrolysis. CHMP2A and CHMP3 copolymerized in solution, and their membrane targeting was cooperatively enhanced on planar lipid bilayers. Such helical CHMP structures could thus assemble within the neck of an inwardly budding vesicle, catalyzing late steps in budding under the control of VPS4.

Investigation of oxidative stress parameters in treated phenylketonuric patients

Phenylketonuria (PKU) is the most frequent disturbance of amino acid metabolism being caused by severe deficiency of phenylalanine hydroxylase activity. Untreated PKU patients present severe mental retardation whose pathophysiology is not completely estabilished. Despite the low-Phe diet, a considerable number of phenylketonuric patients present a mild to moderate psychomotor delay and decreased cognitive functions. In the present study we evaluated various parameters of oxidative stress namely thiobarbituric acid-reactive species (TBA-RS), total antioxidant reactivity (TAR) and activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in two groups of treated PKU patients, one with well controlled and the other with high Phe blood levels in order to investigate whether blood Phe concentrations could be correlated with the extend of oxidative stress. We initially verified a marked increase of TBA-RS, and a decrease of TAR in plasma, as well as a reduction of erythrocyte GSH-Px activity which were similar in both groups of PKU patients, when compared to controls of similar ages. In contrast, CAT and SOD activities were not altered in PKU patients. These results show that oxidative stress occurs in PKU patients and that this pathogenic process is probably not directly correlated to Phe blood levels.

Assessment of a Pioneer Metabolic Information Service in Brazil

The Information Service on Inborn Errors of Metabolism (SIEM), a pioneer toll-free service in both Brazil and South America, is based in Porto Alegre, Southern Brazil. SIEM has been operating since October 2001 providing support to health care professionals involved in the diagnosis and management of suspected metabolic diseases. We analyzed the demographic and clinical characteristics of the 376 consults received and followed in the first two and half years of SIEM. Our results show that the suspicion of a metabolic disease was most often associated with neurological symptoms. Among the consults, 24.4% were eventually confirmed as inborn errors of metabolism (IEM), with organic acidurias and amino acid disorders being the two most frequent diagnostic groups. Our conclusion shows this kind of service to provide helpful support to the diagnosis and acute management of IEM, especially to health professionals working in developing countries who are often far from reference centers.

Group A Streptococci from carriage and disease in Portugal: evolution of antimicrobial resistance and T antigenic types during 2000-2002

In this study, we analyzed the antimicrobial resistance properties and T antigenic types of 511 isolates collected in Lisbon district, Portugal, from throat swabs of healthy subjects (n=341), during 2000-2002 and from diverse infection sites (n=170) of outpatients and inpatients, during 1999-2002. Erythromycin resistance was higher in tonsillitis/pharyngitis (27.4%) and skin infection isolates (21.1%), than in carriage and invasive isolates (<or=10%). Differences in erythromycin resistance among children and adults were noticed only for carriage isolates (9.3% in children and 21.1% in adults). Most erythromycin-resistant isolates from carriage (82.4%) and tonsillitis/pharyngitis (71.9%) showed the M phenotype. All M phenotype isolates (n=53) carried mef(A), whereas all MLS(B) phenotype isolates (n=19) carried erm(B) and not erm(A). Resistance to tetracycline [mediated by tet(M) in most isolates] was <or=6% in tonsillitis/pharyngitis and carriage isolates, 36.8% in skin infection isolates, and 44.1% in invasive isolates. The M phenotype increased since 2000, linked to a decrease of tetracycline resistance, and was predominantly associated with T1 in 2000-2001 and T12 in 2002 among carriage isolates, and with T8/25/Imp19 through 2000-2002 among tonsillitis/pharyngitis isolates. The majority (53%) of the tetracycline-resistant invasive isolates were nontypable. All isolates were susceptible to penicillin and chloramphenicol. This study showed that tetracycline and macrolide resistance frequency and phenotypes differ among GAS from various origins and changed over time. Moreover, T typing suggested that most drug-resistant isolates causing oropharyngeal carriage are distinct from the majority of isolates causing noninvasive and invasive infection.

Sensitivity comparison of real-time PCR probe designs on a model DNA plasmid

We investigated three probe design strategies used in quantitative polymerase chain reaction (PCR) for sensitivity in detection of the PCR amplicon. A plasmid with a 120-bp insert served as the DNA template. The probes were TaqMan, conventional molecular beacon (MB), and shared-stem molecular beacon (ATssMB and GCssMB). A shared-stem beacon probe combines the properties of a TaqMan probe and a conventional molecular beacon. It was found that the overall sensitivities for the four PCR probes are in the order of MB>ATssMB>GCssMB>TaqMan. The fluorescence quantum yield measurements indicate that incomplete or partial enzymatic cleavage catalyzed by Taq polymerase is the likely cause of the low sensitivities of two shared-stem beacons when compared with the conventional beacon probe. A high-fluorescence background associated with the current TaqMan probe sequence contributes to the relatively low detection sensitivity and signal-to-background ratio. The study points out that the nucleotide environment surrounding the reporting fluorophore can strongly affect the probe performance in real-time PCR.

Gaucher disease type 1: Revised recommendations on evaluations and monitoring for adult patients

For patients with type 1 Gaucher disease, challenges to patient care posed by clinical heterogeneity, variable progression rates, and potential permanent disability that can result from untreated or suboptimally treated hematologic, skeletal, and visceral organ involvement dictate a need for comprehensive, serial monitoring. An updated consensus on minimum recommendations for effective monitoring of all adult patients with type 1 Gaucher disease has been developed by the International Collaborative Gaucher Group (ICGG) Registry coordinators. These recommendations provide a schedule for comprehensive and reproducible evaluation and monitoring of all clinically relevant aspects of this disease. The initial assessment should include confirmation of deficiency of beta-glucocerebrosidase, genotyping, and a complete family medical history. Other assessments to be performed initially and at regular intervals include a complete physical examination, patient-reported quality of life using the SF-36 survey, and assessment of hematologic (hemoglobin and platelet count), visceral, and skeletal involvement, and biomarkers. Specific radiologic imaging techniques are recommended for evaluating visceral and skeletal pathology. All patients should undergo comprehensive regular assessment, the frequency of which depends on treatment status and whether therapeutic goals have been achieved. Additionally, reassessment should be performed whenever enzyme therapy dose is altered, or in case of significant clinical complication.

Stray-field imaging and multinuclear magnetic resonance spectroscopy studies on the setting of a commercial glass-ionomer cement

A commercial glass-ionomer (Fuji II) was studied using different NMR techniques. 1H and 19F stray-field imaging (STRAFI) were used to monitor the curing kinetics of the cement and two processes were distinguished: the gelation and maturation phases. Characterization of the aluminium and silicon species present in the glass component and cement was performed by conventional 27Al and 29Si MAS and two-dimensional 27Al triple quantum MAS NMR (MQMAS) techniques. Quantification of the aluminium in the glass component and in the cement indicates the leaching of about 32% of the 4-coordinate aluminium, about 100% of the 5-coordinate aluminium and about 41% of the 6-coordinate aluminium, during the setting reaction. It is also shown that the 5-coordinate aluminium is only present in the surface layer created by the acid attack during the cement formation process. In the cement, silicon maintains species with four bridging oxygens after the leaching of tetrahedral (4-coordinate) aluminium. The silicon analysis correlates well with the aluminium determinations.

Fluorescence resonance energy transfer between donor-acceptor pair on two oligonucleotides hybridized adjacently to DNA template

We use fluorescein as the energy donor and rhodamine as the acceptor to measure the efficiency of fluorescence resonance energy transfer (FRET) in a set of hybridized DNA constructs. The two fluorophores are covalently attached via linkers to two separate oligonucleotides with fluorescein at the 3' end of one oligonucleotide and rhodamine at the 5' end or in the middle of another nucleotide. For the FRET analysis both fluorophore-labeled oligonucleotides are hybridized to adjacent sections of the same DNA template to form a three-component duplex with a one base gap between the two labeled oligonucleotides. A similar configuration is implemented for a quantitative real-time polymerase chain reaction (PCR) with LightCycler technology, where a 1-5 base separation between donor and acceptor is recommended to optimize energy transfer efficiencies. Our constructs cover donor-acceptor separations from 2 to 17 base pairs (approximately 10-70 A). The results show that, when the two fluorophores are located at close distances (less than 8 base separation), FRET efficiencies are above 80%, although there may be ground-state interactions between fluorophores when the separation is under about 6 bases. Modeling calculations are used to predict the structure of these three-component constructs. The duplex mostly retains a normal double helical structure, although slight bending may occur near the unpaired base in the DNA template. Stable and reproducible energy transfer is also observed over the distance range investigated here in real-time thermal cycling. The study identifies important parameters that determine FRET response in applications such as real-time PCR.

Molecular characterization of phenylketonuria in South Brazil

Phenylketonuria (PKU) is an autosomal recessive disorder due to phenylalanine hydroxylase (PAH) deficiency. The PAH gene, located at 12q22-q24.1, includes about 90kb and contains 13 exons. To date, more than 420 different alterations have been identified in the PAH gene. To determine the nature and frequency of PAH mutations in PKU patients from South Brazil, mutation analysis was performed on genomic DNA from 23 unrelated PKU patients. The 13 exons and flanking regions of the PAH gene were amplified by PCR and the amplicons were analyzed by single strand conformation polymorphism (SSCP). Amplicons that showed abnormal migration patterns were analyzed by restriction endonuclease digestion and/or sequencing. Twenty-two previously reported mutations were identified including R261X, R408W, IVS2nt5g-->c, R261Q, and V388M. Polymorphisms were observed in 48.8% of the PKU patients, the most frequent being IVS2nt19t-->c, V245V, and IVS12nt-35c-->t. In addition, two novel sequence variants were identified: 1378g-->t in the 3(')-untranslated region in exon 13 which may be disease-causing and an intron 12 polymorphism, IVS12nt-15t-->c. The mutation spectrum in the patients from Southern Brazil differed from that observed in patients from other Latin American countries and further defined the molecular heterogeneity of this disease.

Detection of organic acidemias in Brazil

BACKGROUND

Organic acidurias or organic acidemias are inherited metabolic disorders in which organic acids (carboxylic acids) accumulate in tissues and physiologic fluids of affected individuals. They are considered the most frequent metabolic disorders among severely ill children. Patients frequently present acute symptoms in early life. Metabolic acidosis and neurologic symptoms are the most common signs.

METHODS

Urine specimens obtained from 1,926 children from January 1994 to July 2001 were used in analyses. Venous blood specimens were also collected from some patients. Samples were initially submitted to screening tests for detection of inborn errors of metabolism. Identification and semi-quantitation of organic acids in urine were performed by gas chromatography or gas chromatography coupled to mass spectrometry using capillary column (DB-5) and flame ionization detection.

RESULTS

Ninety three (4.8%) cases of organic acidemias were diagnosed among 1,926 patients investigated from January 1994 to July 2001. Prompt therapy was instituted after diagnosis in a considerable number of patients and resulted in rapid improvement in their symptomatology, distinct from our previous cases diagnosed abroad where patients representing index cases died before any measure could be taken.

CONCLUSIONS

Results demonstrate the importance of diagnosing organic acidurias in loco in developing countries despite implied extra costs.

Effect of CuCl2, NaCl and EDTA on the enzyme alpha-L-iduronidase in the plasma of normal individuals and heterozygotes for MPS I

BACKGROUND

It has been previously demonstrated that the enzyme alpha-L-iduronidase (IDUA) of patients with MPS I shows a different biochemical behavior in each of the three clinical forms of these. In heterozygotes, its biochemical behavior has been recently established in leukocyte and plasma samples, demonstrating that it is possible to distinguish individuals heterozygous for MPS I within an unselected population.

METHODS

We evaluated the effect of copper chloride, EDTA and sodium chloride on the activity of the enzyme alpha-L-iduronidase in the plasma of normal individuals and of MPS I heterozygotes and observed the type of inhibition caused, the Ki, the apparent Km and the apparent Vmax for each inhibitor.

RESULTS

Sodium chloride inhibited the enzyme in normal individuals and in 40% of the heterozygotes evaluated and activated it in 60% of heterozygotes. The remaining compounds inhibited IDUA in both heterozygotes and normal individuals.

CONCLUSIONS

We detected significant differences capable of differentiating MPS I heterozygotes from normal individuals by simply adding sodium chloride, EDTA or copper chloride to the incubation medium at the time of IDUA activity determination, with a potential use in carrier detection protocols.

Biventricular pacing--early experience

INTRODUCTION

Biventricular pacing has been studied for the treatment of chronic heart failure (CHF). This technique seems to be able to improve symptoms and exercise tolerance, in patients with advanced CHF and prolonged QRS duration.

OBJECTIVE

To present our experience with biventricular pacing in the management of severe CHF.

METHODS

Between June 2000 and March 2001, 8 patients with dilated cardiomyopathy and left bundle branch block (LBBB) were selected for transvenous biventricular pacing system implantation. Mean age: 54.12 +/- 16.8 years; 5 males. The etiology was: idiopathic in 6 cases; operated congenital heart disease in 1, and ischemic in the other. Despite tailored treatment of CHF (with all patients taking diuretics and angiotensin-converting enzyme inhibitors), 7 patients remained in NYHA class III and 1 in IV. The quality of life score (assessed by the "Minnesota living with heart failure questionnaire") was 62.25 +/- 11.29. Seven patients had sinus rhythm and only one chronic atrial fibrillation; mean PQ duration--220 +/- 76.37 ms; mean QRS duration--168.75 +/- 20.31 ms.

RESULTS

Implant failure, due to coronary sinus dissection and to excessive fluoroscopy time, with no coronary sinus catheterization, occurred in 2 cases (success rate: 75%). Implant data: mean implant procedure duration: 122.5 +/- 47.82 min; mean fluoroscopy time: 35.66 +/- 22.06 min; QRS duration, after implant: 133.33 +/- 15.05 ms. Left ventricular lead final position: anterolateral in 2 patients and lateral in 4. Pacing thresholds: biventricular--1.36 +/- 0.6 V; right ventricle--0.28 +/- 0.04 V; right atrium--0.32 +/- 0.08 V. Pacing impedance (left ventricle): 1013.33 +/- 147.87 omega. Follow-up (1st and 3rd month): one patient died, suddenly, 15 days after the procedure. In the others, an improvement in the quality of life index and functional class was found. These results were independent of echocardiography data. There were no significant differences in the pacing threshold and impedance during the follow-up.

CONCLUSIONS

Patients with advanced CHF and widened QRS benefited from biventricular stimulation, in which improvement on the clinical status was evident.

Detection of mucopolysaccharidosis type I heterozygotes on the basis of the biochemical properties of plasma alpha-L-iduronidase

BACKGROUND

Mucopolysaccharidosis type I (MPS I) is a disease caused by deficiency of the enzyme alpha-L-iduronidase (IDUA). Since no treatment is currently available for this disorder, the detection of heterozygotes is very important for genetic counseling and prenatal diagnosis. The objective of the present study was to characterize plasma IDUA from MPS I heterozygotes in an attempt to distinguish it from that of normal individuals.

METHODS

We determined the optimum pH, Km, Vmax and Calpha (Vmax/Km) of the reaction and the thermal stability of IDUA at 50 degrees C.

RESULTS

MPS I heterozygotes can be separated from normal individuals on the basis of Km, Calpha and thermal stability of the enzyme.

CONCLUSIONS

Taking into consideration the clinical status of the homozygous offspring, we were able to subdivide the MPS I heterozygotes into various subgroups (Hurler, Scheie or Hurler/Scheie compound), and verified that the Hurler subgroup had a lower optimum pH for IDUA activity than controls and other MPS I subgroups, and that all MPS I subgroups had higher Km and lower Calpha when compared to controls.

[Organic aciduria: diagnosis in high-risk Brazilian patients]

OBJECTIVE: To determine the prevalence of organic acidurias in high-risk Brazilian patients. METHODS: Laboratory techniques for the detection and quantification of organic acids by gas chromatography/mass spectrometry were implemented in Porto Alegre, Brazil. We investigated 1,480 patients suspected of organic aciduria between January 1994 and June 2000. RESULTS: Seventy three (4.9%) cases of organic acidemias (acidurias) were diagnosed among the tested individuals. In most of these patients, prompt therapy resulted in rapid symptom improvement; these results are completely different from our previous cases diagnosed in other laboratories in Europe and the United States, where several patients died before any measures could be taken. CONCLUSIONS: These results demonstrate the importance of diagnosing organic acidurias in loco even in developing countries, in spite of the extra costs involved.

[Mitral flow propagation velocity assessed with M-mode color Doppler in patients with dilated cardiomyopathy]

BACKGROUND

The role of diastolic disfunction in the setting of severe left ventricular (LV) disfunction is usually forgotten due to difficulties in quantification and interpretation. The propagation velocity (PV) of mitral inflow into the left ventricle has been proposed as a load independent indicator of LV diastolic function. Our aim was to correlate PV with age, body surface, chambers dimensions, wall thickness and with classic parameters of systolic and diastolic function. We had in mind the validation of this index in the quantification of LV filling and in risk stratification of patients with dilated cardiomyopathy (DC).

MATERIAL AND METHODS

We prospectively studied 32 consecutive patients, mean age 56.1 +/- 15.7 years, 22 (68.75%) male, mean ejection fraction 28.1 +/- 7.5%. All of them were in NYHA class < or = II and on ACE inhibitors. Eight (25%) were on beta-blockers. Patients without sinus rhythm, paced or with significant hypertensive, congenital or valvular heart disease were previously excluded. The following parameters of LV systolic function were assessed by echocardiography: fractional shortening, ejection fraction and cardiac output. LV filling was assessed by transmitral flow pulsed Doppler analysis: isovolumic relaxation time (IVRT), peak E and A wave velocities, E wave deceleration time (DT). We also evaluated a new Doppler index of combined systolic and diastolic myocardial performance (Tei index). PV (cm/s) was calculated by Color M-mode. Univariate regression analysis was performed (PV as dependent variable).

RESULTS

We detected a high prevalence of diastolic function disturbances: 25 (78.1%) patients with a delayed relaxation pattern and only 3 (9.4%) with a restrictive pattern. PV did not correlate with age, body surface and LV geometry. There was a significant correlation between PV and E/A ratio (r = 0.61; p < 0.0001), IVRT (r = -0.50; p = 0.006), DT (r = -0.41; p = 0.01) and Tei index (r = -0.36; p = 0.04).

CONCLUSIONS

Our results indicate that, in patients with a predominance of delayed relaxation, there is a strong relationship between PV and the classic parameters of LV filling. For similar levels of systolic impairment, PV could be an easy, fast and reproducible quantitative indicator of severity on DC.

Detection of Leishmania in immunocompromised patients using peripheral blood spots on filter paper and the polymerase chain reaction

The aim of the present study was to investigate whether the polymerase chain reaction could be used to detect Leishmania infantum in peripheral blood spots of immunocompromised patients. Although visceral leishmaniasis in immunocompromised individuals is routinely diagnosed by direct microscopy or by culture of biopsy material, both methods have disadvantages. In order to evaluate an alternative method of diagnosis, blood spots were collected on filter paper from 24 immunocompromised individuals with visceral leishmaniasis diagnosed by bone marrow microscopy or culture. The samples were tested using the polymerase chain reaction. Leishmania DNA was detected in 15 of 20 patients who had not yet begun treatment for Leishmania infection and in two of four patients undergoing treatment. Using microscopy or culture, parasites were detected in 5 of 19 and 8 of 19 fresh blood samples, respectively. The results suggest that the polymerase chain reaction can be used with blood spots on filter paper as an initial screening method for immunocompromised patients suspected to have Leishmania infection.

Biological effects of a bifunctional DNA crosslinker. I. Generation of triradial and quadriradial chromosomes

Interduplex crosslinks by a bifunctional anthramycin DNA crosslinker produced triradial and quadriradial chromosomes. The crosslinker alkylates guanine at N-2. Bovine chromosomes contain GC-rich density satellite DNAs at the centromeric heterochromatin and is the basis for the formation of triradial and quadriradial chromosomes at the centromeres. The in situ crosslinking of interphase chromosomes indicates that the distance between centromeres is 17.5 A. We conclude that the nuclear matrix associated DNA in the centromeric heterochromatin of interphase chromosomes are positioned close enough for crosslinking to occur. We propose a model for the generation of triradial and quadriradial chromosomes based upon the number of interduplex crosslinks between two chromosomes.