Parkin mRNA Expression Levels in Peripheral Blood Mononuclear Cells in Parkin-Related Parkinson's Disease

INTRODUCTION

Pathogenic variants in parkin (PRKN gene) are the second most prevalent known monogenic cause of Parkinson's disease (PD). How monoallelic or biallelic pathogenic variants in the PRKN gene may affect its transcription in patient-derived biological material has not been systematically studied.

METHODS

PRKN mRNA expression levels were measured with real-time polymerase chain reaction (RT-PCR) in peripheral blood mononuclear cells (PBMCs). PBMCs were derived from PRKN-mutated PD patients (PRKN-PD) (n = 12), sporadic PD (sPD) (n = 21) and healthy controls (n = 21). Six of the PRKN-PD patients were heterozygous, four were compound heterozygous, and two were homozygous for PRKN variants.

RESULTS

A statistically significant decrease in PRKN expression levels was present, compared to healthy controls and sPD, in heterozygous (P = 0.019 and 0.031 respectively) and biallelic (P < 0.001 for both) PRKN-PD. PRKN expression levels in biallelic PD patients were uniformly very low and were reduced, albeit not significantly, compared to heterozygotes. Based on receiver operating characteristic analysis, low PRKN expression levels were a sensitive and extremely specific indicator for the presence of PRKN pathogenic variants.

CONCLUSIONS

Assessment of PRKN mRNA levels in PBMCs may be a useful way to screen for biallelic pathogenic variants in the PRKN gene. Suspicion for certain variants in a heterozygous state may also be raised based on low PRKN mRNA levels. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Clinical differences between early-onset and mid-and-late-onset Parkinson's disease: Data analysis of the Hellenic Biobank of Parkinson's disease

BACKGROUND

Age at onset is one of the most critical factors contributing to the clinical heterogeneity of Parkinson's disease (PD), and available evidence is rather conflicting.

OBJECTIVE

The aim of this study is to investigate the clinical differences between early-onset PD (EOPD) and mid-and-late-onset PD (MLOPD) in the Greek population, based on the existing data of the Hellenic Biobank of PD (HBPD).

METHODS

HBPD contains information of PD cases from two centers in Greece during 2006-2017. Patients with the A53T mutation in the SNCA gene or mutations in the GBA1 gene were excluded. Associations between clinical characteristics (motor and non-motor symptoms, side of onset, first symptom, motor complications) and MLOPD versus EOPD were explored with a single logistic regression model adjusting for gender, family history of PD, disease and dopaminergic therapy duration, disease severity (UPDRS III), levodopa equivalent daily dose, as well as each of the other clinical characteristics.

RESULTS

675 patients (129 EOPD, 546 MLOPD) were included. EOPD was more frequently associated with dystonia (OR 0.19, 95% CI 0.08-0.50, p < 0.01) and motor complications (0.23, 0.07-0.76, 0.02), compared to MLOPD. Bilateral onset (9.38, 1.05-84.04, 0.045) and autonomic dysfunction (2.31, 1.04-5.11, 0.04) were more frequently associated with MLOPD.

CONCLUSIONS

EOPD and MLOPD display distinct clinical profiles, regarding motor and non-motor symptoms, side of onset and motor complications in the Greek population. These differences may reflect diverse pathophysiological backgrounds, potentially attributed to genetic or age-related epigenetic influences.

Nurr1 repression mediates cardinal features of Parkinson's disease in α-synuclein transgenic mice

Duplication/triplication mutations of the SNCA locus, encoding alpha-synuclein (ASYN), and loss of function mutations in Nurr1, a nuclear receptor guiding midbrain dopaminergic neuron development, are associated with familial Parkinson’s disease (PD). As we age, the expression levels of these two genes in midbrain dopaminergic neurons follow opposite directions and ASYN expression increases while the expression of Nurr1 decreases. We investigated the effect of ASYN and Nurr1 age-related expression alterations in the pathogenesis of PD by coupling Nurr1 hemizygous with ASYN(s) (heterozygote) or ASYN(d) (homozygote) transgenic mice. ASYN(d)/Nurr1+/− (2-hit) mice, contrary to the individual genetic traits, developed phenotypes consistent with dopaminergic dysfunction. Aging ‘2-hit’ mice manifested kyphosis, severe rigid paralysis, L-DOPA responsive movement impairment and cachexia and died prematurely. Pathological abnormalities of phenotypic mice included SN neuron degeneration, extensive neuroinflammation and enhanced ASYN aggregation. Mice with two wt Nurr1 alleles [ASYN(d)/Nurr1+/+] or with reduced ASYN load [ASYN(s)/Nurr1+/−] did not develop the phenotype or pathology. Critically, we found that aging ASYN(d), in contrast to ASYN(s), mice suppress Nurr1-protein levels in a brain region–specific manner, which in addition to Nurr1 hemizygosity is necessary to instigate PD pathogenesis. Our experiments demonstrate that ASYN-dependent PD-related pathophysiology is mediated at least in part by Nurr1 down-regulation.

A Novel SNCA A30G Mutation Causes Familial Parkinson's Disease

BACKGROUND

The SNCA gene encoding α-synuclein (αSyn) is the first gene identified to cause autosomal-dominant Parkinson's disease (PD).

OBJECTIVE

We report the identification of a novel heterozygous A30G mutation of the SNCA gene in familial PD and describe clinical features of affected patients, genetic findings, and functional consequences.

METHODS

Whole exome sequencing was performed in the discovery family proband. Restriction digestion with Bbvl was used to screen SNCA A30G in two validation cohorts. The Greek cohort included 177 familial PD probands, 109 sporadic PD cases, and 377 neurologically healthy controls. The German cohort included 136 familial PD probands, 380 sporadic PD cases, and 116 neurologically healthy controls. We also conducted haplotype analysis using 13 common single nucleotide variants around A30G to determine the possibility of a founder effect for A30G. We then used biophysical methods to characterize A30G αSyn.

RESULTS

We identified a novel SNCA A30G (GRCh37, Chr4:90756730, c.89 C>G) mutation that co-segregated with the disease in five affected individuals of three Greek families and was absent from controls. A founder effect was strongly suggested by haplotype analysis. The A30G mutation had a local effect on the intrinsically disordered structure of αSyn, slightly perturbed membrane binding, and promoted fibril formation.

CONCLUSION

Based on the identification of A30G co-segregating with the disease in three families, the absence of the mutation in controls and population databases, and the observed functional effects, we propose SNCA A30G as a novel causative mutation for familial PD. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Quantitative determination of aloin, antioxidant activity, and toxicity of Aloe vera leaf gel products from Greece

BACKGROUND

Aloe vera is a popular medicinal plant used widely by the cosmetic, pharmaceutical, and food industries. The A. vera leaf gel, which is used mostly for its positive effects on human health, contains over 75 different bioactive compounds, including aloin. Aloin is a toxic compound, and its content in A. vera leaf gel products depends on the different cultivation conditions and especially on leaf processing.

RESULTS

In this study, A. vera leaf gel products, varied in terms of leaf processing, were analyzed using liquid chromatography for their aloin content, their antioxidant activity by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS^·+ ) and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH^· ) antioxidant activity assays and their toxicity against Aliivibrio fisheri and SH-SY5Y cells. In the samples processed with industrial methods and in those filtered in the lab, the content of aloin was found below the limit (0.1 mg L^-1 ) of the EU legislation however, the unprocessed and unfiltered samples were found to contain more than 10 mg L^-1 . Antioxidant activity was estimated to vary from 1.64 to 9.21 μmol Trolox mL^-1 for DPPH^· and from 0.73 to 5.14 μmol Trolox mL^-1 for ABTS^·+ . Toxicity values on A. fisheri, expressed as the concentration at 50% loss of initial luminescence, ranged from 0.03 to 0.09 mg mL^-1 . The cytotoxic study indicated that aloin A at low concentrations (1 and 10 μg mL^-1 ) protects SH-SY5Y cells from toxicity induced by hydrogen peroxide.

CONCLUSIONS

Consequently, the filtration process of A. vera leaf gels, either laboratory or industrial, resulted in aloin A content below the EU legislation detection limits. © 2020 Society of Chemical Industry.

Differentially Expressed Circular RNAs in Peripheral Blood Mononuclear Cells of Patients with Parkinson's Disease

Background

New noninvasive and affordable molecular approaches that will complement current practices and increase the accuracy of Parkinson's disease (PD) diagnosis are urgently needed. Circular RNAs (circRNAs) are stable noncoding RNAs that accumulate with aging in neurons and are increasingly shown to regulate all aspects of neuronal development and function.

Objectives

Τhe aims of this study were to identify differentially expressed circRNAs in blood mononuclear cells of patients with idiopathic PD and explore the competing endogenous RNA networks affected.

Methods

Eighty‐seven circRNAs were initially selected based on relatively high gene expression in the human brain. More than half of these were readily detectable in blood mononuclear cells using real‐time reverse transcription‐polymerase chain reaction. Comparative expression analysis was then performed in blood mononuclear cells from 60 control subjects and 60 idiopathic subjects with PD.

Results

Six circRNAs were significantly down‐regulated in patients with PD. The classifier that best distinguished PD consisted of four circRNAs with an area under the curve of 0.84. Cross‐linking immunoprecipitation‐sequencing data revealed that the RNA‐binding proteins bound by most of the deregulated circRNAs include the neurodegeneration‐associated FUS, TDP43, FMR1, and ATXN2. MicroRNAs predicted to be sequestered by most deregulated circRNAs have the Gene Ontology categories “protein modification” and “transcription factor activity” mostly enriched.

Conclusions

This is the first study that identifies specific circRNAs that may serve as diagnostic biomarkers for PD. Because they are highly expressed in the brain and are derived from genes with essential brain functions, they may also hint on the PD pathways affected. © 2021 Biomedical Research Foundation, Academy of Athens. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Circulating Brain-enriched MicroRNAs for detection and discrimination of idiopathic and genetic Parkinson's disease

BACKGROUND

A minimally invasive test for early detection and monitoring of Parkinson's disease (PD) is a highly unmet need for drug development and planning of patient care. Blood plasma represents an attractive source of biomarkers. MicroRNAs (miRNAs) are conserved noncoding RNA molecules that serve as posttranscriptional regulators of gene expression. As opposed to ubiquitously expressed miRNAs that control house-keeping processes, brain-enriched miRNAs regulate diverse aspects of neuron development and function. These include neuron-subtype specification, axonal growth, dendritic morphogenesis, and spine density. Backed by a large number of studies, we now know that the differential expression of neuron-enriched miRNAs leads to brain dysfunction.

OBJECTIVES

The aim was to identify subsets of brain-enriched miRNAs with diagnostic potential for familial and idiopathic PD as well as specify the molecular pathways deregulated in PD.

METHODS

Initially, brain-enriched miRNAs were selected based on literature review and validation studies in human tissues. Subsequently, real-time reverse transcription polymerase chain reaction was performed in the plasma of 100 healthy controls and 99 idiopathic and 53 genetic (26 alpha-synuclein^A53T and 27 glucocerebrosidase) patients. Statistical and bioinformatics analyses were carried out to pinpoint the diagnostic biomarkers and deregulated pathways, respectively.

RESULTS

An explicit molecular fingerprint for each of the 3 PD cohorts was generated. Although the idiopathic PD fingerprint was different from that of genetic PD, the molecular pathways deregulated converged between all PD subtypes.

CONCLUSIONS

The study provides a group of brain-enriched miRNAs that may be used for the detection and differentiation of PD subtypes. It has also identified the molecular pathways deregulated in PD. © 2019 International Parkinson and Movement Disorder Society.

Autophagy dysfunction in peripheral blood mononuclear cells of Parkinson's disease patients

BACKGROUND

Alpha-synuclein aggregation is considered one of the main causes of Parkinson's Disease (PD). Malfunction of autophagy-lysosomal pathways is believed to be an underlying mechanism of α-synuclein aggregation. Although such malfunction has been observed in PD brains, it is unclear whether it may also occur in extraneuronal tissues.

OBJECTIVES

To assess lysosome-mediated protein degradation in cultured Peripheral Blood Mononuclear Cells (PBMCs) of PD patients and healthy controls.

METHODS

Total protein degradation in cultured PBMCs was measured by labelling the cells with ³H-leucine using pulse-chase experiments. Different inhibitors were used to measure a range of autophagic pathways.

RESULTS

Protein degradation through the main autophagic pathways is reduced in PD patients (n = 18) compared to age- and sex-matched healthy controls (n = 18), (macroautophagy, p = .018; Chaperone-Mediated autophagy, p = .04; and total lysosomal function, p = .007).

CONCLUSIONS

Lysosomal dysfunction is present in cultured PBMCs of PD patients, suggesting that it may reflect a systemic feature of the disease.

Motor and Nonmotor Features of Carriers of the p.A53T Alpha-Synuclein Mutation: A Longitudinal Study

BACKGROUND

G209A SNCA mutation carriers represent an important group of genetic PD. We describe motor and nonmotor features of G209A SNCA mutation carriers.

METHODS

Longitudinal clinical assessments over 2 years were collected in 22 symptomatic and 8 asymptomatic G209A SNCA mutation carriers. Motor and nonmotor rating scales were administered. Correlations were performed between clinical variables and disease duration or age. Penetrance was calculated using Kaplan-Meier survival curves.

RESULTS

Asymptomatic carriers did not manifest clear premotor symptoms, but symptomatic carriers often reported that olfactory dysfunction and rapid eye movement sleep behavior disorder preceded motor symptoms. Prominent motor decline and deterioration of autonomic and cognitive function occurred at follow-up; such nonmotor features correlated with disease duration, but not age. Disease penetrance was estimated at around 90%.

CONCLUSIONS

This study may help to inform clinical trials and provide the basis for studies of disease modifiers in genetic synucleinopathy cohorts. © 2016 International Parkinson and Movement Disorder Society.

Lysosomal alterations in peripheral blood mononuclear cells of Parkinson's disease patients

BACKGROUND

Reduced expression of lysosomal-associated membrane protein 2a and heatshock-cognate 70 proteins, involved in chaperone-mediated autophagy and of glucocerebrosidase, is reported in PD brains. The aim of this study was to identify systemic alterations in lysosomal-associated membrane protein 2a, heatshock cognate-70, and glucocerebrosidase levels/activity in peripheral blood mononuclear cells from PD patients.

METHODS

Protein/mRNA levels were assessed in PD patients from genetically undetermined background, alpha-synuclein (G209A/A53T), or glucocerebrosidase mutation carriers and age-/sex-matched controls.

RESULTS

Heatshock cognate 70 protein levels were reduced in all PD groups, whereas its mRNA levels were decreased only in the genetically undetermined group. Glucocerebrosidase protein levels were decreased only in the genetic PD groups, whereas increased mRNA levels and decreased activity were detected only in the glucocerebrosidase mutation group.

CONCLUSIONS

Reduced heatshock cognate-70 levels are suggestive of an apparent systemic chaperone-mediated autophagy dysfunction irrespective of genetic background. Glucocerebrosidase activity may serve as a screening tool to identify glucocerebrosidase mutation carriers with PD.

Genetic assessment of familial and early-onset Parkinson's disease in a Greek population

BACKGROUND AND PURPOSE

Although the first mutation associated with Parkinson's disease (PD) was identified several years ago in the alpha-synuclein (SNCA) gene in families of Greek and Italian ancestry, a more systematic study of this and other known PD mutations has not been performed in the Greek population.

METHODS

A genetic analysis in 111 familial or sporadic with early-onset (≤50 years, EO) PD patients was performed for the presence of the A53T SNCA mutation. In separate subgroups of these patients, further mutations in the SNCA, LRRK2, Parkin, PINK1 and DJ-1 genes were searched for. Additionally, a subgroup of familial cases was analysed for mutations in the glucocerebrosidase (GBA) gene.

RESULTS

In total, five patients (4.5% of our whole population) were identified with the A53T SNCA mutation, two with a heterozygote dosage mutation and one with a heterozygote point mutation in the Parkin gene, and seven patients (10.3% of our familial cohort) with GBA gene mutations.

CONCLUSIONS

The A53T mutation in the SNCA gene, although uncommon, does represent a cause of PD in the Greek population, especially of familial EOPD with autosomal dominant inheritance. GBA mutations in the familial cohort tested here were as common as in a cohort of sporadic cases previously examined from the same centres. For the remainder of the genes, genetic defects that could definitively account for the disease were not identified. These results suggest that further Mendelian traits that lead to PD in the Greek population remain to be identified.

Inflammatory and oxidative stress biomarkers in allergic rhinitis: the effect of smoking

BACKGROUND

Accumulating evidence confirms the presence of pan-airway inflammation in allergic rhinitis patients. Smoking is known to affect the asthmatic airway inflammation. However, no study has evaluated the impact of smoking on airway inflammation of allergic rhinitis patients.

OBJECTIVE

The aim of the present study was to evaluate the impact of smoking on inflammatory and oxidative stress biomarkers in patients with seasonal allergic rhinitis, using non-invasive methods for sample collection.

METHODS

Forty patients with seasonal allergic rhinitis (20 smokers and 20 non-smokers) and 30 healthy subjects (15 smokers and 15 non-smokers) were recruited for the study during pollen season. All subjects were submitted to measurement of the fraction of exhaled NO (FeNO), exhaled breath condensate (EBC) collection, nasal lavage collection, pre- and post- bronchodilation spirometry and metacholine bronchial challenge testing. pH, leukotriene B(4) (LTB(4)) and 8-isoprostane were determined in EBC and nasal lavage samples.

RESULTS

Patients with allergic rhinitis presented higher LTB(4) and 8-isoprostane levels in nasal lavage (P<0.0001 for both comparisons), with no significant differences between smokers and non-smokers. Patients with allergic rhinitis also presented higher LTB(4) levels and lower pH in EBC (P<0.001 and P=0.004, respectively), with prominent differences between smokers and non-smokers (P<0.0001 and P=0.003, for LTB(4) and pH, respectively). A significant correlation between nasal lavage and EBC LTB(4) values was observed (r(s)=0.313, P=0.048).

CONCLUSIONS

Patients with allergic rhinitis present increased LTB(4) and 8-isoprostane in their nasal cavity, however, with no significant differences between smokers and non-smokers. In contrast, smokers with allergic rhinitis present higher LTB(4) levels and lower pH in EBC, suggesting that these patients may be more susceptible to the deleterious effects of smoking, compared with non-smokers.

Spread of efflux pump-overexpressing, non-metallo-β-lactamase-producing, meropenem-resistant but ceftazidime-susceptible Pseudomonas aeruginosa in a region with blaVIM endemicity

OBJECTIVES

To investigate the resistance mechanisms of meropenem-resistant, ceftazidime-susceptible Pseudomonas aeruginosa isolates, in a clinical setting where VIM-2 or VIM-4 metallo-beta-lactamase (MBL)-producing pseudomonads are common.

METHODS

During May to December 2003, 13 consecutive meropenem-resistant, ceftazidime-susceptible P. aeruginosa isolates were recovered from separate patients at the University Hospital of Larissa, Thessaly, Greece. The isolates were studied by Etest MBL, PCR for blaVIM, blaIMP and blaSPM genes and PFGE. Experiments were performed to detect synergy between meropenem or other antimicrobials and the efflux pump inhibitor carbonyl cyanide-m-chlorophenylhydrazone (CCCP). The isolates were also tested by PCR and RT-PCR for the expression of the genes mexB and mexY, which encode the efflux pumps MexAB-OprM and MexXY-OprM.

RESULTS

Twelve of the isolates, belonging to six distinct PFGE types, gave negative results in the MBL Etest and lacked genes encoding MBLs but exhibited synergy between meropenem and CCCP, indicating that efflux pump activity contributed to the meropenem resistance. All 12 isolates were positive for mexB and 11 were also positive for mexY genes. RT-PCR showed that 10 and five isolates over-expressed mexB and mexY, respectively. One isolate was blaVIM-2-positive and did not show synergy with CCCP, or harbour mexB or mexY.

CONCLUSIONS

In our hospital, where MBL-producing P. aeruginosa were previously prevalent, meropenem resistance due to the overexpression of efflux pumps has also now emerged. Early recognition of this resistance mechanism should allow the use of alternative beta-lactams, such as ceftazidime, which would be inactive even against phenotypically susceptible MBL producers.

Apoptosis and the conformational change of Bax induced by proteasomal inhibition of PC12 cells are inhibited by bcl-xL and bcl-2

The function of the proteasome has been linked to various pathologies, including cancer and neurodegeneration. Proteasomal inhibition can lead to death in a variety of cell types, however the manner in which this occurs is unclear, and may depend on the particular cell type. In this work we have extended previous findings pertaining to the effects of pharmacological proteasomal inhibitors on PC12 cells, by examining in more detail the induced death pathway. We find that cell death is apoptotic by ultrastructural criteria. Caspase 9 and 3 are processed, cytochrome c is released from the mitochondria and a dominant negative form of caspase 9 prevents death. Furthermore, Bax undergoes a conformational change and is translocated to the mitochondria in a caspase-independent fashion. Total cell levels of Bax however do not change, whereas levels of the BH3-only protein Bim increase with proteasomal inhibition. Transient overexpression of bcl-xL or, to a lesser extent, of bcl-2, significantly decreased apoptotic death and prevented Bax conformational change. We conclude that death elicited by proteasomal inhibition of PC12 cells follows a classical "intrinsic" pathway. Significantly, antiapoptotic bcl-2 family members prevent apoptosis by inhibiting Bax conformational change. Increased levels of Bim may contribute to cell death in this model.

RAIDD is required for apoptosis of PC12 cells and sympathetic neurons induced by trophic factor withdrawal

Caspase 2 has been implicated in trophic deprivation-induced neuronal death. We have shown that overexpression of the caspase 2-binding protein RAIDD induces neuronal apoptosis, acting synergistically with trophic deprivation. Currently, we examine the role of endogenous RAIDD in apoptosis of PC12 cells and sympathetic neurons. Expression of a truncated caspase recruitment domain-only form of caspase 2, which presumably disrupts the RAIDD interaction with endogenous caspase 2, attenuated trophic deprivation-induced apoptosis. Furthermore, downregulation of RAIDD by small interfering RNA led to inhibition of trophic deprivation-induced death, whereas death induced by DNA damage, which is not caspase 2-mediated, was not inhibited. Therefore, RAIDD, likely through interaction with caspase 2, is involved in trophic deprivation-induced neuronal apoptosis. This is the first demonstration of the involvement of RAIDD in apoptosis, and provides further support for the idea that apoptotic pathways in the same system may differ depending on the initiating stimulus.

Clonal dissemination of mupirocin-resistant staphylococci in Greek hospitals

OBJECTIVES

To determine the rates of mupirocin resistance in staphylococci during a 4 year period (1999-2002) in Greece.

MATERIALS

A total of 1200 Staphylococcus aureus and 2760 coagulase-negative staphylococci (CoNS), consecutively collected from four Greek hospitals located in different geographical areas, were tested for susceptibility to mupirocin using the Etest and a reference agar dilution method.

RESULTS

Twenty-four S. aureus (2%) and 532 CoNS (19.2%) were found to be mupirocin-resistant during the study period. High-level mupirocin resistance was detected in 20 S. aureus (1.6%) and in 440 CoNS (15.9%), respectively. No variations in the rates of mupirocin-resistant S. aureus in relation to the year of collection were observed. In contrast, the rate of mupirocin-resistant CoNS increased dramatically from 9% in 1999, to 14% in 2000, 20% in 2001 and reached 33% in 2002. PFGE analysis revealed the presence of one main clone (A) among mupirocin-resistant S. aureus and two main clones (i and a) among Staphylococcus epidermidis isolates.

CONCLUSIONS

In Greece, the rate of mupirocin-resistant S. aureus has remained low and steady since 1999. The high rate of mupirocin-resistant CoNS (33%) in 2002 was due mainly to clonal dissemination of epidemic hospital clones.

Evaluation of a novel method based on PCR Restriction Fragment Length Polymorphism Analysis of the tuf gene for the identification of Staphylococcus species

A novel method, based on PCR Restriction Fragment Length Polymorphism Analysis (PRA) of a part of the tuf gene (370 bp), was designed for the identification of 11 staphylococcal species, including the most common staphylococcal pathogens. A total of 258 clinical isolates were validated by this assay, and the results were in concordance with those obtained by the reference method of Kloos and Schleifer.

Multicenter evaluation of the fully automated bactec MGIT 960 system and three molecular methods for the isolation and the identification of mycobacteria from clinical specimens

A combination of Bactec MGIT 960 system, a PCR-based assay and a PCR-Restriction Analysis procedure (PRA) was assessed for the detection and identification of mycobacteria from clinical samples. The MGIT recovered 243 from 266 mycobacterial isolates. The PCR-based assay correctly identified all (234) Mycobacterium tuberculosis isolates, while 35 nontuberculous mycobacterial isolates were identified by PRA.

Hospital outbreak of multiple clones of Pseudomonas aeruginosa carrying the unrelated metallo-beta-lactamase gene variants blaVIM-2 and blaVIM-4

OBJECTIVES

The possible contribution of metallo-beta-lactamases in the frequent detection of carbapenem-resistant Pseudomonas aeruginosa isolates in a tertiary Greek hospital in Central Greece was investigated.

MATERIALS AND METHODS

All carbapenem-resistant (imipenem- and/or meropenem-resistant) P. aeruginosa isolates recovered from separate patients during a 1 year period in the Clinical Microbiology Laboratory at the University Hospital of Thessaly, Larissa, Greece, were studied for metallo-beta-lactamases. They were tested by Etest MBL, PCR analysis and nucleotide sequencing. DNA fingerprints were obtained by pulsed-field gel electrophoresis (PFGE) of XbaI-digested chromosomal DNA.

RESULTS

A blaVIM gene was detected in 47 of the 53 (88.7%) carbapenem-resistant P. aeruginosa isolates. PFGE grouped the blaVIM-positive isolates in six unrelated genotypes; one type included two subtypes. Nucleotide sequencing of the PCR amplicons of a randomly selected isolate from each one of the seven subtypes, detected the variant sequences blaVIM-2 in four and blaVIM-4 in three cases, respectively. They were carried as single gene cassettes or along with an aminoglycoside resistance gene (aacA29a) in class 1 integrons.

CONCLUSIONS

These findings suggest that different strains of P. aeruginosa carrying unrelated metallo-beta-lactamase gene variants predominate in our hospital environment.

Survey of methicillin-resistant coagulase-negative staphylococci in the hospitals of central Greece

A sample of 450 consecutive, non-replicated coagulase-negative staphylococci (CoNS), collected from clinical specimens during the period 2000-2001 from the five major hospitals of Thessaly district (Central Greece) were investigated for resistance to methicillin. Most of the isolates had been collected in a sporadic fashion from the intensive care units and the surgical wards of the participating hospitals. The majority of the isolates (76%) were Staphylococcus epidermidis (50%), Staphylococcus haemolyticus (14.8%) and Staphylococcus hominis (11.1%). All 316 isolates (70%) were classified as resistant according to NCCLS breakpoints (MIC > or =0.5 mg/l); 268 (59.5%) of them were mecA-positive in a PCR-based assay. All isolates with MIC > or =8 mg/l carried the gene, while, only 23.8% of isolates with MIC, 0.5-4 mg/l were carriers. Only 9% of the mecA-positive isolates were found to be sensitive to various non-beta-lactams, while 41.8% of the isolates were resistant to more than three antimicrobial groups apart from beta-lactams. Molecular typing by PFGE showed apparent heterogeneity among isolates of each species and the absence of predominant clones.

Methicillin-resistant Staphylococcus aureus in the hospitals of central Greece

A total of 250 consecutive Staphylococcus aureus clinical isolates were collected during the period 1999-2000 from the five major hospitals of the district of Thessaly (Central Greece). Thirty seven (14.8%) of the isolates were mecA-positive (MRSA) in a PCR-based assay; all exhibited resistance to oxacillin (agar dilution MICs > or =4 mg/L) and were also resistant to multiple antibiotics. Most of the MRSA isolates had been collected in the intensive care units and the surgical wards of the participating hospitals in a sporadic fashion. The MRSA incidence found here was significantly lower than reported in previous studies from Greece. Molecular typing by PFGE showed that the MRSA isolates were distributed between three pulsotypes. Evaluation of various conventional methods for assessing methicillin resistance showed that oxacillin agar dilution and immunological detection of PBP2a with the Slidex MRSA Detection kit were the most reliable in this setting. Misclassifications of isolates exhibiting low-level resistance (oxacillin MIC 2-4 mg/L) occurred with the salt agar screen, the oxacillin disk diffusion and the ATB Staph System methods.

Maternal expressed emotion and metabolic control of children and adolescents with diabetes mellitus

BACKGROUND

The objectives of this study of children and adolescents with diabetes were to: (1) examine whether maternal expressed emotion (EE), in the form of critical comments (CC), hostility and emotional overinvolvement (EOI), is related to metabolic control; (2) determine if CC and EOI are separately related to poor metabolic control, and (3) ascertain whether high EE is related to psychopathology in these children.

METHODS

The Present Episode version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children (Kiddie-SADS-P/K-SADS-P) interview was administered to 55 children and adolescents with diabetes and the parental EE instrument, the 5-min speech sample, to 55 mothers. The same instruments were utilized with the 54 controls and their mothers. Glycosylated hemoglobin A1 values were used as a measure of metabolic control.

RESULTS

More than half of the children with diabetes (58.2%) had mild to moderate symptoms of anxiety or depression as compared to 9.3% of the controls. High EE was exhibited by 70.9% of the index group mothers in contrast to only 29.6% of the control group mothers. High maternal EE was not related to the psychopathology of children with diabetes. High maternal EE and in particular its EOI component and excessive detail (a subcategory of EOI) were related to poor metabolic control of the index children.

CONCLUSIONS

Maternal EE is related to metabolic control in childhood diabetes; maternal EOI in particular is related to poor metabolic control. Mental health professionals should work with mothers of children with diabetes in an effort to modify such attitudes and emotions.

Lung involvement in primary Sjögren's syndrome is mainly related to the small airway disease

OBJECTIVE

To evaluate lung involvement in patients with primary Sjögren's syndrome.

METHODS

Sixty one consecutive, non-smoking patients, 58 women and three men, were evaluated clinically, physiologically, and radiologically. A bronchial and/or transbronchial biopsy was performed on 13 of the patients. Physiological data were compared with that of a control group of 53 healthy non-smoking subjects matched for age and sex.

RESULTS

In 41% of the patients the main symptom was dry cough. Physiological studies revealed that the patients presented significantly lower expiratory flow values (% pred) when compared with those of the control group: the forced expiratory volume in one second (FEV1) (mean (SD)) was 96% (16) v 111% (13) (p < 0.0001), the maximal expiratory flow at the 50% of the vital capacity (MEF50) was 72% (24) v 103% (17) (p < 0.0001), and the maximal expiratory flow at the 25% of the vital capacity (MEF25) was 49% (25) v 98% (20) (p < 0.0001). No significant difference was noted for the carbon monoxide diffusion value (% pred), between patients and controls. Blood gases were evaluated in 44 patients: mild hypoxemia was observed, and the alveolo-arterial oxygen difference (P(A-a)O2) correlated significantly with MEF50 (r = 0.35, p < 0.01) and MEF25 (r = 0.33, p < 0.01) values. Chest radiography showed mild, interstitial-like changes in 27 patients while slightly increased markings were present in 21. High resolution computed tomography of the lungs was performed in 32 patients (four with a normal chest radiograph, six with suspected interstitial pattern, 19 with apparent interstitial pattern, and three with hyperinflation) and revealed predominantly wall thickening at the segmental bronchi. All positive findings by computed tomography derived from the patients with abnormal chest radiographs. Transbronchial and/or endobronchial biopsy specimens in 10 of the 11 sufficient tissue samples revealed peribronchial and/or peribronchiolar mononuclear inflammation, while interstitial inflammation coexisted in two patients.

CONCLUSION

The airway epithelia seem to be the main target of the inflammatory lesion of the lung in patients with primary Sjögren's syndrome. It seems to be common, subclinically leading to obstructive small airway physiological abnormalities.