Pharmacokinetics of gentamicin in critically ill patients: pilot study evaluating the first dose

Gentamicin is extensively used in the treatment of severe Gram-negative bacterial infections. A loading dose of 7 mg/kg is recommended to achieve a maximum concentration (C(max)) above 16 mg/L. We studied gentamicin pharmacokinetic data from patients treated between January 2006 and June 2008 in two intensive-care units. The Sawchuk and Zaske one-compartment pharmacokinetic model was used to estimate the gentamicin volume of distribution (the 32 patients had a median age of 68 years (23 men)). The median volume of distibution (V(d)) per kilogram of body weight (V(d)/kg) was 0.41 L/kg (interquartile range of 0.36-0.46 L/kg), with no correlations with age, Charlson comorbidity score, sequential organ failure assessment (SOFA) score and creatinine serum level (r(2) = 0.016, 0.058, 0.037, and 0.067, respectively). Women had a significantly higher median V(d)/kg (0.50 vs. 0.40 L/kg, p 0.002) and lower C(max) (15.2 vs. 18.5 mg/L, p 0.016), despite similar dose/kg. In a logistic regression model, only sex (female: OR 0.032; 95% CI 0.03-0.387) and dose/kg (per mg/kg: OR 3.21; 95% CI 1.17-8.79) were significantly associated with the achievement of C(max) above 16 mg/L. Gentamicin clearance was 57 mL/min (interquartile range of 44.7-78 mL/min) and decreased with age (r(2) = 0.178, p 0.016), SOFA score (r(2) = 0.199, p 0.011) and creatinine clearance (r(2) = 0.258, p 0.003). Gentamicin V(d) was increased in critically ill patients, particularly in women. Therefore, high gentamicin loading doses should be given to all patients, especially women, independently of organ failure. Gentamicin clearance decreases with age, SOFA score, and renal failure.

Expression, mutation and copy number analysis of platelet-derived growth factor receptor A (PDGFRA) and its ligand PDGFA in gliomas

BACKGROUND

Malignant gliomas are the most prevalent type of primary brain tumours but the therapeutic armamentarium for these tumours is limited. Platelet-derived growth factor (PDGF) signalling has been shown to be a key regulator of glioma development. Clinical trials evaluating the efficacy of anti-PDGFRA therapies on gliomas are ongoing. In this study, we intended to analyse the expression of PDGFA and its receptor PDGFRA, as well as the underlying genetic (mutations and amplification) mechanisms driving their expression in a large series of human gliomas.

METHODS

PDGFA and PDGFRA expression was evaluated by immunohistochemistry in a series of 160 gliomas of distinct World Health Organization (WHO) malignancy grade. PDGFRA-activating gene mutations (exons 12, 18 and 23) were assessed in a subset of 86 cases by PCR-single-strand conformational polymorphism (PCR-SSCP), followed by direct sequencing. PDGFRA gene amplification analysis was performed in 57 cases by quantitative real-time PCR (QPCR) and further validated in a subset of cases by chromogenic in situ hybridisation (CISH) and microarray-based comparative genomic hybridisation (aCGH).

RESULTS

PDGFA and PDGFRA expression was found in 81.2% (130 out of 160) and 29.6% (48 out of 160) of gliomas, respectively. Its expression was significantly correlated with histological type of the tumours; however, no significant association between the expression of the ligand and its receptor was observed. The absence of PDGFA expression was significantly associated with the age of patients and with poor prognosis. Although PDGFRA gene-activating mutations were not found, PDGFRA gene amplification was observed in 21.1% (12 out of 57) of gliomas. No association was found between the presence of PDGFRA gene amplification and expression, excepting for grade II diffuse astrocytomas.

CONCLUSION

The concurrent expression of PDGFA and PDGFRA in different subtypes of gliomas, reinforce the recognised significance of this signalling pathway in gliomas. PDGFRA gene amplification rather than gene mutation may be the underlying genetic mechanism driving PDGFRA overexpression in a portion of gliomas. Taken together, our results could provide in the future a molecular basis for PDGFRA-targeted therapies in gliomas.

An AcrAB-mediated multidrug-resistant phenotype is maintained following restoration of wild-type activities by efflux pump genes and their regulators

In this study, we aimed to answer the following question: 'How does a bacterium become so resistant to a given antibiotic even though the levels of antibiotic to which it has become resistant remained constant in the patient?'Escherichia coli AG100 strain induced to high-level resistance due to overexpression of an AcrAB efflux pump was serially cultured in 10mg/L tetracycline for 60 passages. Between each passage it became increasingly resistant to tetracycline, beta-lactams and quinolones with concomitant restoration of wild-type AcrAB activity. Because the multidrug-resistant phenotype could not be reversed with transfer to drug-free medium or with efflux pump inhibitors, it may have resulted from activation of a 'mutator gene' system that reduced the 'energy consumption' associated with an overexpressed efflux pump system.

Feline sporotrichosis in the southern region of rio grande do sul, Brazil: clinical, zoonotic and therapeutic aspects

Clinical cases of feline sporotrichosis, originating in the Pelotas region and diagnosed at the Laboratory of Infectious Diseases (UFPel), were studied in the period from 2002 to 2006. The animals were evaluated according to the clinical forms of the mycosis, time of lesion appearance, severity of the clinical diagnosis and evolution of cutaneous lesions throughout the treatment period. Mycological analyses, carried out through direct examination, cultivation of tissue samples and exudates of feline lesions all confirmed the diagnosis of sporotrichosis in the 15 animals under study. The cutaneous dissemination form was observed in 10 animals, of which three showed prostration, anorexia and dehydration. The zoonosis occurred in 20% of case studies, and the pet owners and one attendant at a veterinary clinic were infected, developing the fixed and disseminated cutaneous forms. The treatment of mycosis was carried out with itraconazole, 10 mg kg(-1), once a day, on 12 animals. The cure of the clinical symptoms was observed on 50% of the felines. This study demonstrates a good clinical response of felines with sporotrichosis, when they were treated itraconazole and calls the attention for the incidence of human sporotrichosis on people related to the veterinary activity as well as for pet owners.

Biomonitoring hospital effluents by the Allium cepa L. test

Hospital effluents are serious problems in developing countries like Brazil, and when not treated adequately, can cause mutagenic effects on live organisms. Biomonitors, like Allium cepa L., which is one of the most used plant species when monitoring effluent genotoxicity, have been used to alert the world population about environmental contamination and genotoxic chemical emissions. The Allium cepa test was used to evaluate the genotoxicity of a hospital effluent in Santa Maria, Rio Grande do Sul State, Brazil. During the study, chromosomal disruptions, anaphasic bridges, and micronuclei during telophase were observed, indicating environmental toxicity risk.

Degradable particulate composite reinforced with nanofibres for biomedical applications

Nanofibre-based structures and their composites are increasingly being studied for many biomedical applications, including tissue engineering scaffolds. These materials enable architectures resembling the extracellular matrix to be obtained. The search for optimized supports and carriers of cells is still a major challenge for the tissue engineering field. The main purpose of this work is to develop a novel composite structure that combines microparticles and nanofibres in reinforced polymeric microfibres. This innovative combination of materials is obtained by melting extrusion of a particulate composite reinforced with chitosan nanofibre meshes (0.05 wt.%) produced by the electrospinning technique. The reinforced microfibres were analysed by scanning electron microscopy and showed a considerable alignment of the chitosan nanofibres along the longitudinal main axis of the microfibre composite structure. The tensile mechanical properties revealed that the introduction of the nanofibre reinforcement in the particulate microfibre composite increased the tensile modulus by up to 70%. The various structures were subjected to swelling and degradation tests immersed in an isotonic saline solution at 37 degrees C. The presence of chitosan nanofibres in the particulate microfibres enhances the water uptake by up to 24%. The combination of good mechanical properties and enhanced degradability of the developed structures is believed to have great potential for various biomedical applications, including three-dimensional fibre mesh scaffolds to be applied in the field of bone tissue engineering.

Dayhospital of the Psychiatry Department of Hospital De São João: The Last Three and a Half Years

The Day Hospital of Hospital de São João was one of the pioneers in Portugal, and it began to work in July 1970. In those days, the main purpose was to reduce the number of full hospitalizations, and to aid the reinsertion of patients discharged from the Inpatient Unit. In a previous study, presented in the I Congresso Nacional de Psiquiatria (2005, Portugal), the first 34 years of this Day Hospital (from 1970 to 2004) were analyzed - some changes were noted during that period, namely the type of diagnosis and the hospitalization length. The main purpose of the present study was to characterize the patients that were treated in the Day Hospital of Hospital de São João during the last 3 and half years (Jan 2005- Jul 2008; n = 302), according to age, gender, diagnosis, length of hospitalization, and occupation rate. Then, these data were compared to the data of the previous study (firsts 34 years, in groups of 5 years). For this purpose, the authors used the Qui Square Test and the Kruskal - Wallis Test. It was also analyzed the distribution of the diagnosis according to gender and to length of hospitalization.

Compared Diagnostic Stability Between Mood Disorders and Psychotic Disorders in a Day-care Psychiatric Unit

Psychiatric diagnosis depends more from the experts' opinion than from the biological basis of the diseases. Therefore the lack of diagnostic stability among the psychiatric practice is not a rare situation. This usually results in increased costs in treatment and sometimes in worst outcome for the patient who is misdiagnosed at the onset of the illness.

The authors evaluated diagnostic stability among a population of 302 patients receiving psychiatric treatment in a day-care unit of a central hospital between January/2005 and June/2008. The study compared diagnostic stability of 146 patients diagnosed as mood disorder with diagnostic stability of 83 patients diagnosed as psychotic disorder.

There was high diagnostic stability either for mood disorders as for psychotic disorders. This fact provides the chance of planning more accurate treatment strategies and better outcome.

224 USE OF STATISTICAL MODELS BASED ON BAYESIAN INFERENCE TO ESTIMATE FIELD FERTILITY OF NELORE BULLS BY USING DATA OBTAINED IN AN IN VITRO FERTILIZATION PROGRAM

The aim of the present study was to analyze the use of in vitro fertilization to predict the field fertility of Nelore bulls by using statistical models based on Bayesian inference. A total of 407 oocytes were obtained from slaughterhouse ovaries and submitted to in vitro maturation in TCM-199 and fertilization in Tyrode’s + BSA + lactate + pyruvate. Sperm cells from 3 different bulls, namely, V, T, and G, were used. All bulls had a known field gestational rate. After 18 h of IVF, a sample of zygotes (n = 40/bull) was stripped and stained with acetic orcein (1%) to estimate the number of pronuclei. The remaining zygotes (n = 287) were cultured in SOF for 7 to 8 days. The results are based on 3 replicates with 32 to 33 oocytes/bull per replicate. All 3 bulls analyzed presented similar percentages of oocytes with at least 2 pronuclei (52.5, 40, and 40% for bulls V, T, and G, respectively). However, when cleavage rate was analyzed, bull T presented a significantly (P = 0.0022) lower rate (57.4%) compared with bulls V (77.9%) and G (78.1%). In contrast, blastocyst formation rates were similar between bulls (27.9, 22.8, and 30.5% for bulls V, T, and G, respectively). When the cleavage and blastocyst rates were analyzed in comparison with the field pregnancy rates previously obtained for bulls V, T, and G by using statistic models based on Bayesian inference, the predictions of conception rate based on cleavage were 59.8 ± 2.5%, 54.2 ± 4.7%, and 59.8 ± 2.5% for bulls V, T, and G, respectively. When blastocyst formation rates were used, the predicted conception rate was 58.5 ± 2.2%, 52.3 ± 4.5%, and 61.5 ± 2.8% for bulls V, T, and G, respectively. The predicted conception rates obtained by using the cleavage and blastocyst data together were 54.7 ± 3.9%, 54.1 ± 4.8%, and 63.0 ± 3.1% for bulls V, T, and G, respectively, which was very similar to the real field conception rates for the same bulls (54.4, 54.1, and 63.3%, respectively). The statistical model obtained through the use of Bayesian inference with the combined data for cleavage and blastocyst rates presented a good correlation with the real field fertility of bulls used in this experiment. This result indicates that this statistical method could be a good and efficient alternative to predict the fertility of Nelore bulls. However, a larger number of animals will need to be tested by the same methodology to confirm these results. FAPESP.

Day Hospital and Then…follow-up Two and a Half Years After the Hospitalization

Psychiatry Day Hospitals deal with a wide spectrum of disorders, being responsible for a psychosocial intervention that intends to improve patient's quality of life. The Psychiatry Day Hospital Department of Hospital de São João has thirty-eight years of activity, and has been one of the first in Portugal. The aim of this Psychiatry Unit, composed by a multidisciplinary team, is to prevent relapses and rehospitalisations, promoting the patients’ social rehabilitation, building a bridge between inpatient hospitalization and their re-entry into the community.

The primary objective of this cross-sectional study was to evaluate important aspects of service's quality, such as the use of health resources and results in functional terms. The authors made the follow-up of the patients that had been admitted in 2005 (Jan 2005 - Dez 2005; n= 77). For this purpose, it was assessed the number of attendances to the Emergency Department and hospitalizations two and a half years before and after the treatment in Day Hospital. It was also compared their current employment situation to that which preceded the Day Hospital care.

This study was performed in clinical setting among a reduced sample, with the inherent limitations. It would be appealing to replicate this investigation in a larger population and including some other variables.

Diagnostic Stability of Psychotic Disorders: A Retrospective Study

Background:

An essential condition to validate a diagnosis is its stability over time. Since there are no biological markers for psychiatric disorders, the diagnosis relies on clinical expertise, with several consequences in treatment planning, disease burden and disability, affecting outcome and public health.

Objectives:

The aims of this study were:

1.

Methods:

This was a retrospective study carried out in the Department of Psychiatry of a large University Hospital (Hospital S. João, Porto, Portugal). Patients enrolled were admitted in the inpatient unit from 2000 to 2003 (n=190, 12.41% of 1531 patients admitted), experienced a first psychotic episode, and fulfilled criteria for one of the following diagnosis: schizophrenia, schizoaffective disorder, bipolar disorder, drug induced psychosis, acute and transient psychotic disorders, schizophreniform disorder and psychosis NOS (ICD-10 classification). the diagnoses were extracted from clinical records, and reassessed five years after the initial diagnosis. the analysis focuses on diagnostic agreement over time; clinical and demographic variables were also collected and putative associations with diagnostic shift considered.

Results:

The study is now under statistic evaluation.

[Grey platelet disease]

Grey Platelet disease is a rare disease characterized by morphologic changes in platelets alpha-granules. These proteins are essential for the homeostasis, so the patients with this blood defect present hemorrhagic disturbs. The blood discrasia is usually mild, however some patients could present more serious manifestations, usually after a severe trauma. The authors present the following clinical report about a patient that was admitted in a Medical Department with a severe bleeding and mild thrombocytopenia. The patient was submitted to an extensive study to determine the etiology (autoimmunity serology, myelogram, coagulation study) that were all normal. The diagnosis of Idiopathic Thrombocytopenic Purpura was considered. Six months after a worsening of the hemorrhagic discrasia and thrombocytopenia the patient was assisted. Corticotherapy was initiated without improvement. The morphology of the platelets was revised and the blood smear with Wright coloration revealed the presence of large, pale and grey platelets. The electronic microscopy confirmed the diagnosis of Grey Platelet disease. The family of the patient was studied and we found that two direct relatives were affected with the same disease. In these family these syndrome probably has autossomic dominant inherence.

Diagnostic Stability of Mood Disorders in a Psychiatry Day-hospital

Mood disorders are common and account for one of the greatest causes of disability worldwide. Accordingly, those conditions are frequent among patients treated in Psychiatry Day-Hospitals facilities. Patients referred for treatment in Hospital de São João Day-Hospital have a previous variable period of follow-up in ambulatory clinic or hospitalization, commonly, with an established diagnosis. Notwithstanding, during the Day-Hospital stay, diagnosis may be reviewed because of new clinical data. Diagnostic stability over time is an important issue in clinical practice because it may influence treatment and, therefore, the final outcome. It is closely related with the contact between the patient and the healthcare system. Diagnostic instability is commonly due to fluctuation of disease manifestation over time or presence of co-morbid psychiatric illness in combination with rigid diagnostic criteria. The main objective of this study is to evaluate the diagnosis stability of Mood Disorders among patients treated in a Psychiatry Day-Hospital, applying ICD-10. The clinical sample includes patients admitted to Hospital de São João Psychiatry Day-Hospital whose main diagnosis is a Mood Disorder (F30-39), in the period between January 2005 and June 2008. Admission and delivery diagnosis were compared for each patient in this diagnostic category. Results suggest a high level of stability in this diagnostic group in the Day Hospital setting. For global conclusions about stability of Mood Disorders it would be interesting to replicate this study with larger samples and in different settings.

Screening BRCA1 and BRCA2 unclassified variants for splicing mutations using reverse transcription PCR on patient RNA and an ex vivo assay based on a splicing reporter minigene

BACKGROUND

Many unclassified variants (UV) of BRCA1 or BRCA2 may have an effect on pre-mRNA splicing. Patient blood samples suitable for RNA extraction are not always available for testing UVs at the RNA level.

METHODS

Analyses of RNA from patient peripheral blood were performed, using a one-step reverse transcriptase-PCR (RT-PCR) protocol, and were compared with an ex vivo splicing assay based on PCR-amplified patient DNA inserted into a splicing reporter minigene. Using both methods 20 variants found in 17 patients were examined.

RESULTS

Data from patient RNA and from the minigene assay were fully concordant, but the ex vivo splicing assay, which is monoallelic, clarified several ambiguities in the patient RNA data. Two intronic variants induced strong splicing defects: BRCA1 c.4987-5T-->A (IVS16-5T-->A) induced exon 17 skipping and BRCA2 c.316+5G-->C (IVS3+5G-->C) induced complete skipping of exon 3. Of the exonic variants, BRCA2 c.7805G-->C (p.Arg2602Thr), at the last base of exon 16, induced both exon skipping and activation of a cryptic exonic donor site, and BRCA2 c.8023A-->G (p.Ile2675Val) generated a strong donor site within exon 18. These four variants were thus classified as pathogenic, because of the total absence of a normal transcript from the corresponding allele. Variant BRCA2 c.9501+3A-->T (IVS25+3A-->T) induced incomplete skipping of exon 25, suggesting a mutation with incomplete penetrance, and BRCA2 c.8257_8259del (p.Leu2753del) modified the alternative splicing of exons 17 and 18.

CONCLUSIONS

We show that functional analysis using a splicing reporter minigene is sensitive and specific, and should be used for initial screening of potential splicing defects, especially when patient RNA is not readily available.