Analysis of a direct access testing system for the detection of SARS-CoV-2 in the paediatric population attending school

Background

During the COVID-19 pandemic, the paediatric population plays a minor role in the spread of the SARS-CoV-2 virus. However, in order to keep schools open and reduce SARS-CoV spreading, it is necessary to identify and isolate early SARS-CoV-2 positive paediatric patients even if they are asymptomatic. The aim of this study was to describe a setting for SARS-CoV 2 testing based on the spontaneous presentation of paediatric patients attending school without a medical prescription and explore its appropriateness.

Study design

Cross-sectional study.

Methods

The study performed between September 2020 and March 2021 among a sample of 13,283 paediatric patients who underwent a swab in four different hospital settings (school hot spot, emergency department, day hospital setting and hospital wards). For each patients we collected: date of swab execution, type of swab, execution setting of the swab, result of the swab, information about community spread of the virus in the 14 days prior to the swab execution, sex and age.

Results

In our sample, females accounted for 45.8%. The median age was 6.8 years (IQR 3.0-11.2) and the most frequent age category was between 6 and 11 years (27.9%). At multivariable models with a swab tested positive as outcome. The swabs executed in all the hospital settings had a lower likelihood of resulting positive compared with the school hot spot setting. Compared with adolescents aged between 14 and 19 years old, new-borns below 3 months (adjOR 1.83, 95% C.I. 1.14-3) and patients aged between 11 and 14 years old (adjOR 1.32, 95% C.I. 1.07-1.63) reported a higher probability of a swab tested positive. Instead, children aged between 3 months and 3 years (adjOR 0.77, 95% C.I. 0.61-0.96) and children aged between 3 years and 6 years (adjOR 0.66, 95% C.I. 0.53-0.83) were less likely to result positive. The higher was the mean of pooled Rt in the 14 days preceding the swab, the higher was the likelihood of resulting positive (adjOR 1.75, 95% C.I. 1.53-1.99).

Conclusion

In conclusion, we found a high incidence of paediatric patients positive to the test for the detection of SARS-CoV-2 at the school hot spot compared with other settings during the period of observation. The free access modality to the nasopharyngeal swab was effective in identifying patients with COVID-19. Public health authorities should implement these testing modality in order to help reduce the spread of SARS-CoV-2 in school settings.

Clinical and microbiological characteristics of bacterial infections in patients with cirrhosis. A prospective cohort study from Argentina and Uruguay

INTRODUCTION AND OBJECTIVES

there is insufficient data regarding bacterial infections in patients with cirrhosis to support recommendations for empiric antibiotic treatments, particularly in Latin America. This study aimed to evaluate bacterial infection's clinical impact and microbiological characteristics, intending to serve as a platform to revise current practices.

MATERIALS AND METHODS

a multicenter prospective cohort study of patients with cirrhosis and bacterial infections from Argentina and Uruguay. Patients and infection-related information were collected, focusing on microbiology, antibiotic susceptibility patterns, and outcomes.

RESULTS

472 patients were included. Spontaneous bacterial infections and urinary tract infections (UTI) were registered in 187 (39.6%) and 116 (24.6%) patients, respectively, representing the most common infections. Of the 256 culture-positive infections, 103 (40.2%) were caused by multidrug-resistant organisms (reaching 50% for UTI), and 181 (70.7%) received adequate initial antibiotic treatment. The coverage of cefepime and ceftriaxone was over 70% for the empirical treatment of community-acquired spontaneous infections, but ceftazidime´s coverage was only 40%. For all cases of UTI and for healthcare-associated or nosocomial spontaneous bacterial infections, the lower-spectrum antibiotics that covered at least 70% of the isolations were imipenem and meropenem. During hospitalization, a second bacterial infection was diagnosed in 9.8% of patients, 23.9% required at least one organ support, and 19.4% died.

CONCLUSIONS

short-term mortality of bacterial infections in patients with cirrhosis is very high, and a high percentage were caused by multidrug-resistant organisms, particularly in UTIs. The information provided might serve to adapt recommendations, particularly related to empirical antibiotic treatment in Argentina and Uruguay. The study was registered in Clinical Trials (NCT03919032).

Norfloxacin prophylaxis effect on multidrug resistance in patients with cirrhosis and bacterial infections

It is unclear whether norfloxacin predisposes to infections by multidrug-resistant organisms (MDROs). We aimed to evaluate if patients with cirrhosis receiving norfloxacin prophylaxis at the time of the diagnosis of bacterial infections were more likely to present a multidrug-resistant isolate than those without prophylaxis. This is a cross-sectional study of hospitalized patients with cirrhosis and bacterial infections from Argentina and Uruguay (NCT03919032) from September 2018 to December 2020. The outcome variable was a multidrug-resistant bacterial infection. We used inverse probability of treatment weighting to estimate the odds ratio (OR) of norfloxacin on infection caused by MDROs considering potential confounders. Among the 472 patients from 28 centers, 53 (11%) were receiving norfloxacin at the time of the bacterial infection. Patients receiving norfloxacin had higher MELD-sodium, were more likely to have ascites or encephalopathy, to receive rifaximin, beta-blockers, and proton-pump inhibitors, to have a nosocomial or health-care-associated infection, prior bacterial infections, admissions to critical care units or invasive procedures, and to be admitted in a liver transplant center. In addition, we found that 13 (24.5%) patients with norfloxacin and 90 (21.5%) of those not receiving it presented infections caused by MDROs (adjusted OR 1.55; 95% CI: 0.60-4.03; p = 0.360). The use of norfloxacin prophylaxis at the time of the diagnosis of bacterial infections was not associated with multidrug resistance. These results help empiric antibiotic selection and reassure the current indication of norfloxacin prophylaxis in well-selected patients.Study registration number: NCT03919032.

Analysis of a test system for the detection of SARS-CoV-2 in children attending school

Background

During the COVID-19 pandemic, in order to keep schools open and reduce SARS-CoV spreading, SARS-CoV-2 positive paediatric patients (PP) need to be isolated early. The aim of this study was to describe the appropriateness of school hot spot (HS) for SARS-CoV 2 testing based on open access of PP in a paediatric hospital in Turin, Italy.

Methods

A cross-sectional study was performed between September 2020 and March 2021. The data collected included: date of swab execution, type of swab, execution setting of the swab, result of the swab, sex, age of PP and the mean value of the Rt (reproductive number) of pandemic in the Piedmont region. We collected data about PP from four different hospital settings (HS, Emergency department, day hospital and hospital wards) of Regina Margherita Children’s Hospital (Turin, Italy). We analyzed a sample of 13,283 PP (aged 0-19 years) testing for SARS-CoV-2. The main outcome was the likelihood of testing positive in different settings and in different age groups.

Results

In Our sample, females were 45.8%. The median age was 6.8 years (IQR 3.0-11.2). The swabs executed in all the hospital settings had a lower likelihood of resulting positive compared with the school HS setting. Newborns below 3 months (adj OR 1.85, 95%CI 1.14 - 3) and patients aged between 11 and 13 years old (adj OR 1.32, 95%CI 1.07 - 1.63) reported a higher probability of a swab tested positive compared to adolescents. Instead, children aged between 3 months and 2 years (adj OR 0.77, 95%CI 0.61 - 0.96) and aged between 3 years and 5 years (adj OR 0.66, 95%CI 0.53 - 0.83) were less likely to result positive.

Conclusions

We found a high prevalence of PP positive to the test for the detection of SARS-CoV-2 at the school hot spot compared with other settings. The open access modality to the nasopharyngeal swab was effective in identifying PP with COVID-19. Public health authorities should implement this testing modality in order to reduce SARS-CoV-2 infections in PP.

Key messages

• Open access testing system to detect SARS-CoV-2 is important to do as many tests as possible to identify COVID-19 patients and isolate them in the pediatric population.

• The open access testing modality to detect COVID-19 patients saves time for doctors who, instead of carrying out the patient history, can devote themselves to other clinical activities.

P-720 Frequency of recessive genetic mutations in gamete donation program participants

Study question

Is it possible to determine which are the most prevalent genetic diseases in our argentinian gamete donor population to develop a regional genetic panel and carry out correct pre-reproductive counseling?

Summary answer

We found the most frequent recessive genetic diseases in the gamete donor population, and determined the frequency of positives and negatives for all analyzed mutations.

What is known already

The access of the population with fertility problems to the gamete donation program is every day more frequent. The analysis of recessive genetic mutations of both recipients and gamete donors is essential to ensure the absence of some diseases in the offspring. There are different ways to study the carrier of monogenic diseases, one of them is the CGT® (CARRIER GENETIC TEST), which could be performed on individuals with no previous personal or family history of disease in order to have knowledge of the asymptomatic carrier status and to reduces the incidence of genetic abnormalities.

Study design, size, duration

Retrospective descriptive study. 586 blood samples obtained in Nascentis (Cordoba) from December 2016 to November 2019 were analyzed. Of these, 159 were from donors who belonged to the gamete donation program.

Participants/materials, setting, methods

CGT® results of 159 donors of both sexes were analyzed. A blood sample was drawn from each patient and the kit was sent to Igenomix® for the corresponding CGT® analysis. A complete list of mutations was obtained, the most frequent were identified and the frequency of each one was calculated. We also created the ranking of the fifteen most frequent mutations in the population of oocyte and sperm donors.

Main results and the role of chance

The 159 CGT® analysis allowed us to compile a list of a total of 63 diseases present in the sample. 78.3% of the donors presented one or more mutations. 69.4% of women and 78.5% of men were positive for at least one mutation. Among men, the most frequent mutation was phenylketonuria (18.1%). Among women, the most frequent were Usher syndrome (8%), Oculocutaneous albinism type 2, Glycine encephalopathy and cystic fibrosis (5%). Other frequent ones were Wilson's disease, central core congenital myopathy, and retinitis pigmentosa.

Limitations, reasons for caution

It is possible that an increase in the number of CGT® analyzed slightly modifies some of the positions in the ranking of diseases, so it is suggested to carry out studies with a larger sample size in order to obtain more comprehensive conclusions.

Wider implications of the findings

The analysis of recessive genetic mutations of the gamete donors represents a fundamental tool to avoid the appearance of diseases in the offspring. Each fertility center should know the frequency of occurrence of the most common and/or serious diseases in order to obtain safer results in each of their treatments.

Trial registration number

not applicable

A water-filled garment to protect astronauts during interplanetary missions tested on board the ISS

As manned spaceflights beyond low Earth orbit are in the agenda of Space Agencies, the concerns related to space radiation exposure of the crew are still without conclusive solutions. The risk of long-term detrimental health effects needs to be kept below acceptable limits, and emergency countermeasures must be planned to avoid the short-term consequences of exposure to high particle fluxes during hardly predictable solar events. Space habitat shielding cannot be the ultimate solution: the increasing complexity of future missions will require astronauts to protect themselves in low-shielded areas, e.g. during emergency operations. Personal radiation shielding is promising, particularly if using available resources for multi-functional shielding devices. In this work we report on all steps from the conception, design, manufacturing, to the final test on board the International Space Station (ISS) of the first prototype of a water-filled garment for emergency radiation shielding against solar particle events. The garment has a good shielding potential and comfort level. On-board water is used for filling and then recycled without waste. The successful outcome of this experiment represents an important breakthrough in space radiation shielding, opening to the development of similarly conceived devices and their use in interplanetary missions as the one to Mars.

Biomarkers of Tuberculosis Severity and Treatment Effect: A Directed Screen of 70 Host Markers in a Randomized Clinical Trial

More efficacious treatment regimens are needed for tuberculosis, however, drug development is impeded by a lack of reliable biomarkers of disease severity and of treatment effect. We conducted a directed screen of host biomarkers in participants enrolled in a tuberculosis clinical trial to address this need. Serum samples from 319 protocol-correct, culture-confirmed pulmonary tuberculosis patients treated under direct observation as part of an international, phase 2 trial were screened for 70 markers of infection, inflammation, and metabolism. Biomarker assays were specifically developed for this study and quantified using a novel, multiplexed electrochemiluminescence assay. We evaluated the association of biomarkers with baseline characteristics, as well as with detailed microbiologic data, using Bonferroni-adjusted, linear regression models. Across numerous analyses, seven proteins, SAA1, PCT, IL-1β, IL-6, CRP, PTX-3 and MMP-8, showed recurring strong associations with markers of baseline disease severity, smear grade and cavitation; were strongly modulated by tuberculosis treatment; and had responses that were greater for patients who culture-converted at 8weeks. With treatment, all proteins decreased, except for osteocalcin, MCP-1 and MCP-4, which significantly increased. Several previously reported putative tuberculosis-associated biomarkers (HOMX1, neopterin, and cathelicidin) were not significantly associated with treatment response. In conclusion, across a geographically diverse and large population of tuberculosis patients enrolled in a clinical trial, several previously reported putative biomarkers were not significantly associated with treatment response, however, seven proteins had recurring strong associations with baseline radiographic and microbiologic measures of disease severity, as well as with early treatment response, deserving additional study.

Unusual pleural effusion from vulvar squamous cell carcinoma: report of a case and review of the literature

Vulvar tumors are not very common and account for about 4% of all cancers affecting the female genital organs. Frequently, malignant neoplasia of this site have squamous phenotype and the rare cases of metastasization are reported in the locoregional lymph nodes and in the surrounding organs. We report a case of metastasization of a vulvar squamous cell carcinoma in an unusual place such as the parietal pleura, in a relapsing patient that was submitted to a surgical vulvectomy the previous year.

Caspase-8 as a regulator of tumor cell motility

The caspases are a family of ubiquitously expressed cysteine proteases best known for their roles in programmed cell death. However, caspases play a number of other roles in vertebrates. In the case of caspase-8, loss of expression is an embryonic lethal phenotype, and caspase-8 plays roles in suppressing cellular necrosis, promoting differentiation and immune signaling, regulating autophagy, and promoting cellular migration. Apoptosis and migration require localization of caspase-8 in the periphery of the cells, where caspase-8 acts as part of distinct biosensory complexes that either promote migration in appropriate cellular microenvironments, or cell death in inappropriate settings. In the cellular periphery, caspase-8 interacts with components of the focal adhesion complex in a tyrosine-kinase dependent manner, promoting both cell migration in vitro and metastasis in vivo. Mechanistically, caspase-8 interacts with components of both focal adhesions and early endosomes, enhancing focal adhesion turnover and promoting rapid integrin recycling to the cell surface. Clinically, this suggests that the expression of caspase-8 may not always be a positive prognostic sign, and that the role of caspase-8 in cancer progression is likely context-dependent.

Coaxial biopsy during percutaneous vertebroplasty in patients with presumed osteoporotic vertebral compression fractures: retrospective review of biopsy results

PURPOSE

This study retrospectively analysed the results of biopsies obtained during percutaneous vertebroplasty (PVP) in patients with presumed osteoporotic vertebral compression fractures, with a view to highlighting the importance of coaxial biopsy in determining the aetiology of vertebral fractures and planning subsequent treatment.

MATERIALS AND METHODS

Between November 2003 and March 2009, 98 patients (78 women; 20 men) with a clinical and imaging suspicion of osteoporotic vertebral compression fractures underwent coaxial biopsy in conjunction with PVP of the thoracic and lumbar vertebrae. Mean age at the time of the procedure was 72.6 years. A pathologist interpreted all the biopsy samples.

RESULTS

In 83 patients, the biopsy results were consistent with the presumed osteoporotic aetiology. In two patients, a malignancy was identified. Biopsy samples from 13 patients were considered insufficient or unsuitable by the pathologist for evaluation.

CONCLUSIONS

Despite the number of biopsy samples considered insufficient or unsuitable, coaxial biopsy during PVP is useful in verifying the presumed aetiology of vertebral compression fractures, which is often unclear on the basis of clinical and imaging examinations. It is therefore both convenient and advisable to perform a vertebral coaxial biopsy in all patients undergoing a PVP.

Patient and operator exposure during percutaneous vertebroplasty

PURPOSE

The purpose of this study was to compare exposure of patient and operator to ionising radiation during percutaneous vertebroplasty performed under combined computed tomography (CT) and fluoroscopic guidance or fluoroscopic guidance alone.

MATERIALS AND METHODS

With the collaboration of our physics department, we measured exposure on ten patients undergoing vertebroplasty with combined CT and fluoroscopic guidance and on ten undergoing vertebroplasty with fluoroscopic guidance alone.

RESULTS

Mean operator dose was approximately 0.8 microSv during vertebroplasty done with combined CT and fluoroscopic guidance and 5.8 microSv in procedures with fluoroscopic guidance alone. Mean patient dose was approximately 6 mSv for combined guidance and 8 mSv for fluoroscopic guidance, a difference that was not found to be statistically significant.

CONCLUSIONS

Although combined CT and fluoroscopic guidance is normally preferred for difficult areas such as the cervical and upper thoracic vertebrae, to ensure operator radiation protection, the technique should also be considered for areas normally treated under fluoroscopic guidance alone. However, a larger patient series is needed to correctly evaluate the real contribution of low-dose CT to patient exposure.

Femoral haemostosis with Vasoseal ES: experience in 150 patients

PURPOSE

The aim of this study is to assess the effectiveness and safety of the use of Vasoseal ES collagen plug in heavily anticoagulated patients with high risk of complications at the vascular access site who had undergone vascular radiological intervention.

MATERIALS AND METHODS

Between January 2002 and March 2003 180 consecutive transfemoral arterial accesses in 169 patients subjected to vascular radiological procedures were performed (bilateral access was performed in 11 patients): 140 percutaneous transluminal angioplasties and 40 transarterial chemoembolisations. All the patients who underwent angioplasty were given 3,000 IU of sodic heparin intravenously during the procedure and later a prolonged antiaggregant therapy was undertaken (ticlopidine 500 mg/day and aspirin 150 mg/day). The sheaths were removed at the end of the surgical manoeuvre and two cartridges of collagen were positioned on the external surface of the artery. The mean values of platelets and partial thromboplastin time were 42,000/ml and 170 s, respectively, in cirrhotic patients against 250,000/ml and 200 s in patients with peripheral arteriopathy. The next day a colour Doppler examination was performed at the puncture site.

RESULTS

The technique proved successful in 89.4% of cases (161/180). In 19/180 vascular accesses placement of the haemostatic cartridges was not possible owing to the inability to compress the common femoral artery proximal to the release site (4/19), owing to a pre-existing haematoma (5/19) and owing to the limited presence of subcutaneous tissue (10/19). The mean time required for the placement of Vasoseal ES was 4 min. The mean time-to-haemostasis was 6 min. The mean time-to-mobilisation was 4 hr. Only in two patients was there an onset of a pseudoaneurysm of the right common femoral artery; the lesions were treated with ultrasonography -guided compression. In addition, 16 small local haematomas were recorded. In 4 cases early re-puncture of the femoral artery was performed (24-48 hr following the use of the device) without consequences.

CONCLUSIONS

Vasoseal ES is a safe collagen closure device characterised by a high success rate. In anticoagulated patients the device can reduce the time-to-mobilisation and the incidence of complications.

Optical response to LASIK surgery for myopia from total and corneal aberration measurements

PURPOSE

To evaluate the optical aberrations induced by LASIK refractive surgery for myopia on the anterior surface of the cornea and the entire optical system of the eye.

METHODS

Total and corneal aberrations were measured in a group of 14 eyes (preoperative myopia ranging from -2.5 to -13 D) before and after LASIK surgery. Total aberrations were measured using a laser ray-tracing technique. Corneal aberrations were obtained from corneal elevation maps measured using a corneal system and custom software. Corneal and total wave aberrations were described as Zernike polynomial expansions. Root-mean-square (RMS) wavefront error was used as a global optical quality metric.

RESULTS

Total and corneal aberrations (third-order and higher) showed a statistically significant increase after LASIK myopia surgery, by a factor of 1.92 (total) and 3.72 (corneal), on average. This increase was more pronounced in patients with the highest preoperative myopia. There is a good correlation (r = 0.97, P < 0.0001) between the aberrations induced in the entire optical system and those induced in the anterior corneal surface. However, the anterior corneal spherical aberration increased more than the total spherical aberration, suggesting also a change in the spherical aberration of the posterior corneal surface. Pupil centration and internal optical aberrations, which are not accounted for in corneal topography, play an important role in evaluating individual surgical outcomes.

CONCLUSIONS

Because LASIK surgery induces changes in the anterior corneal surface, most changes in the total aberration pattern can be attributed to changes in the anterior corneal aberrations. However, because of individual interactions of the aberrations in the ocular components, a combination of corneal and total aberration measurements is critical to understanding individual outcomes, and by extension, to designing custom ablation algorithms. This comparison also reveals changes in the internal aberrations, consistent with the posterior corneal changes reported using scanning slit corneal topography.

HIV-1 Tat causes apoptotic death and calcium homeostasis alterations in rat neurons

We investigated the role of the HIV-1 protein Tat in AIDS-associated dementia, by studying its toxicity on rat cortical and hippocampal neurons in vitro. We evaluated the involvement of astroglial cells and of caspase transduction pathway in determining Tat toxicity. Here we report that synthetic Tat(1-86) induced apoptotic death on cultured rat neurons in a time-dependent manner that was not influenced by glial coculture, and that was abolished by blocking caspase transduction pathway. A microfluorimetric analysis on the Tat excitatory properties on neurons, and its effect on intracellular calcium concentrations, revealed that Tat(1-86) induced increase in cytoplasmic free calcium concentrations in rat hippocampal and cortical neurons. This effect required extracellular calcium and was differently reduced by voltage dependent calcium channel blockers and both NMDA and non-NMDA glutamate receptors antagonists. Furthermore, we observed that Tat(1-86)-treated neurons showed increased sensitivity to the glutamate excitotoxicity. Thus, the Tat-induced neuronal injury seems to occur through a direct interaction of the protein with neurons, requires activation of caspases, and is likely to derive from Tat(1-86)-induced calcium loads and disruption of glutamatergic transmission.

Chemokines and their receptors in the central nervous system

Chemokines are a family of proteins associated with the trafficking of leukocytes in physiological immune surveillance and inflammatory cell recruitment in host defence. They are classified into four classes based on the positions of key cystiene residues: C, CC, CXC, and CX3C. Chemokines act through both specific and shared receptors that all belong to the superfamily of G-protein-coupled receptors. Besides their well-established role in the immune system, several recent reports have demonstrated that these proteins also play a role in the central nervous system (CNS). In the CNS, chemokines are constitutively expressed by microglial cells, astrocytes, and neurons, and their expression can be increased after induction with inflammatory mediators. Constitutive expression of chemokines and chemokine receptors has been observed in both developing and adult brains, and the role played by these proteins in the normal brain is the object of intense study by many research groups. Chemokines are involved in brain development and in the maintenance of normal brain homeostasis; these proteins play a role in the migration, differentiation, and proliferation of glial and neuronal cells. The chemokine stromal cell-derived factor 1 and its receptor, CXCR4, are essential for life during development, and this ligand-receptor pair has been shown to have a fundamental role in neuron migration during cerebellar formation. Chemokine and chemokine receptor expression can be increased by inflammatory mediators, and this has in turn been associated with several acute and chronic inflammatory conditions. In the CNS, chemokines play an essential role in neuroinflammation as mediators of leukocyte infiltration. Their overexpression has been implicated in different neurological disorders, such as multiple sclerosis, trauma, stroke, Alzheimer's disease, tumor progression, and acquired immunodeficiency syndrome-associated dementia. An emerging area of interest for chemokine action is represented by the communication between the neuroendocrine and the immune system. Chemokines have hormone-like actions, specifically regulating the key host physiopathological responses of fever and appetite. It is now evident that chemokines and their receptors represent a plurifunctional family of proteins whose actions on the CNS are not restricted to neuroinflammation. These molecules constitute crucial regulators of cellular communication in physiological and developmental processes.

Stromal cell-derived factor-1alpha induces astrocyte proliferation through the activation of extracellular signal-regulated kinases 1/2 pathway

Stromal cell-derived factor-1 (SDF-1), the ligand of the CXCR4 receptor, is a chemokine involved in chemotaxis and brain development that also acts as co-receptor for HIV-1 infection. We previously demonstrated that CXCR4 and SDF-1alpha are expressed in cultured type-I cortical rat astrocytes, cortical neurones and cerebellar granule cells. Here, we investigated the possible functions of CXCR4 expressed in rat type-I cortical astrocytes and demonstrated that SDF-1alpha stimulated the proliferation of these cells in vitro. The proliferative activity induced by SDF-1alpha in astrocytes was reduced by PD98059, indicating the involvement of extracellular signal-regulated kinases (ERK1/2) in the astrocyte proliferation induced by CXCR4 stimulation. This observation was further confirmed showing that SDF-1alpha treatment selectively activated ERK1/2, but not p38 or stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK). Moreover, both astrocyte proliferation and ERK1/2 phosphorylation, induced by SDF-1alpha, were inhibited by pertussis toxin (PTX) and wortmannin treatment indicating the involvement of a PTX sensitive G-protein and of phosphatidyl inositol-3 kinase in the signalling of SDF-1alpha. In addition, Pyk2 activation represent an upstream components for the CXCR4 signalling to ERK1/2 in astrocytes. To our knowledge, this is the first report demonstrating a proliferative effect for SDF-1alpha in primary cultures of rat type-I astrocytes, and showing that the activation of ERK1/2 is responsible for this effect. These data suggest that CXCR4/SDF-1 should play an important role in physiological and pathological glial proliferation, such as brain development, reactive gliosis and brain tumour formation.

Ocular aberrations before and after myopic corneal refractive surgery: LASIK-induced changes measured with laser ray tracing

PURPOSE

To determine objectively the changes in the ocular aberrations (3rd order and above) induced by myopic LASIK refractive surgery and its impact on image quality.

METHODS

The ocular aberrations of 22 normal myopic eyes (preoperative refraction ranged from -13 to -2 D) were measured before (2.9 +/- 4.3 weeks) and after (7.7 +/- 3.2 weeks) LASIK refractive surgery using a laser ray tracing technique. A set of laser pencils is sequentially delivered onto the eye through different pupil locations. For each ray, the corresponding retinal image is collected on a CCD camera. The displacement of the image centroid with respect to a reference provides direct information of the ocular aberrations. Root-mean-square (RMS) wavefront error was taken as image quality metric.

RESULTS

RMS wavefront error increased significantly in all eyes but two after surgery. On average, LASIK induced a significant (P = 0.0003) 1.9-fold increase in the RMS error for a 6.5-mm pupil. The main contribution was due to the increase (fourfold, P < 0.0001) of spherical aberration. The increase in the RMS for a 3-mm pupil (1.7-fold) was also significant (P = 0.02). The modulation transfer (computed for 6.5-mm pupil) decreased on average by a factor of 2 for middle-high spatial frequencies.

CONCLUSIONS

(1) Laser ray tracing is a well-suited, robust, and reliable technique for the evaluation of the change of ocular aberrations with refractive surgery. (2) Refractive surgery induces important amounts of 3rd and higher order aberrations. The largest increase occurs for spherical aberration. Decentration of the ablation pattern seems to generate 3rd order aberrations. (3) This result is important for the design of customized ablation algorithms, which should cancel existing preoperative aberrations while avoiding the generation of new aberrations.

Immunofluorescence and biochemical techniques to detect nuclear localization of ciliary neurotrophic factor in glial cells

Ciliary neurotrophic factor (CNTF) promotes the survival of several populations of neurons, including sensory and motor neurons. It is mainly produced by Schwann cells and astrocytes and exerts its biological function via a specific membrane receptor. We recently determined the nuclear localization of CNTF in producing cells, after transfection and in the heterologous system of Xenopus oocytes. In the present paper, we describe in detail the techniques for the detection of CNTF in the nucleus of rat astrocytes, transfected cells, isolated nuclei and injected Xenopus oocytes.

Glial and neuronal cells express functional chemokine receptor CXCR4 and its natural ligand stromal cell-derived factor 1

Chemokines are a family of proteins that chemoattract and activate cells by interacting with specific receptors on the surface of their targets. The chemokine stromal cell-derived factor 1, (SDF1), binds to the seven-transmembrane G protein-coupled CXCR4 receptor and acts to modulate cell migration, differentiation, and proliferation. CXCR4 and SDF1 are reported to be expressed in various tissues including brain. Here we show that SDF1 and CXCR4 are expressed in cultured cortical type I rat astrocytes, cortical neurons, and cerebellar granule cells. In cortical astrocytes, prolonged treatment with lipopolysaccharide induced an increase of SDF1 expression and a down-regulation of CXCR4, whereas treatment with phorbol esters did not affect SDF1 expression and down-modulated CXCR4 receptor expression. We also demonstrated the ability of human SDF1alpha (hSDF1alpha) to increase the intracellular calcium level in cultured astrocytes and cortical neurons, whereas in the same conditions, cerebellar granule cells did not modify their intracellular calcium concentration. Furthermore, in cortical astrocytes, the simultaneous treatment of hSDF1alpha with the HIV-1 capside glycoprotein gp120 inhibits the cyclic AMP formation induced by forskolin treatment.

Expression of chemokine receptors in the rat brain

Human immunodeficiency virus (HIV-1) infects the brain and causes a progressive encephalopathy in 20 to 30% of infected children and adults called AIDS dementia complex. Evidence from in vitro and in vivo studies suggests a role for the viral envelope glycoprotein gp120, as a mediator of neurotoxicity. However, the site of interaction of gp120 with neurons and astrocytes to mediate neuronal death is still unknown. Recently the chemokine receptors, CCR5 and CXCR4, have been identified as co-receptors together with CD4 for HIV-1 entry into the target cells, suggesting a possible role for these receptors in the pathogenesis of the HIV-1 infection in the brain. Here we report the expression of CCR5 and CXCR4 in many different rat brain areas. We also found both receptors in cultured type I astrocytes demonstrating that glial cells may represent an important target for chemokines in vivo. Indeed, the functional capacity of CXCR4 receptor in astrocytes was demonstrated showing that SDF 1 alpha induced an increase of intracellular calcium concentration.

Transcatheter arterial chemoembolization in hepatocellular carcinoma. Our experience

BACKGROUND

The results of transcatheter arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) in comparison to other treatments are investigated.

METHODS

121 patients were treated in 186 sessions in our Institute from January 1991 to January 1996.

RESULTS

The mean survival rates at 1 year were 41.5 and 24.4% at 2 years. The patient's survival period was significantly longer in Child A-B patients, and in those on whom multiple sessions were performed. Personal experience in chemoembolization on HCC are better when compared to the natural history of those untreated patients but worse when compared to the data reported in literature about surgery and PEI (Percutaneous Ethanol Injection). It must be made clear though the all surgery case reports do not included class C Child patients whereas PEI is not carried out on those lesions with a diameter greater than 5 cm and plurifocal ones. Our case reports, on the other hand, as most other case reports found in the literature on chemoembolization having results similar to ours, include those patients normally not included in surgical or PEI case reports; this obviously causes the worsening of the results on global patient survival.

CONCLUSIONS

Our hypothesis is that in the future the first choice in non-surgical treatment will be an association of TACE and other treatments (PEI and radiofrequency) on Child A and B patients having capsulated lesions >3 cm.

Detection of high- and moderately high-level resistance to gentamicin and streptomycin in Enterococcus faecium by a disc diffusion method

We evaluated an agar disc diffusion test for the detection of high-level (> or = 2000 mg/L) and moderately high-level resistance to gentamicin (MIC, > or = 128- < or = 1024 mg/L) and streptomycin (MIC, > or = 256- < or = 1024 micrograms/ml) with 70 clinical isolates of Enterococcus faecium. Results obtained using disks containing 120 micrograms gentamicin and 300 micrograms streptomycin were compared with MICs determined by an agar dilution method. Based on the scattergrams, the closest zone diameter correlations with MIC breakpoints were as follows: susceptible, > or = 16 mm; and resistant, < or = 10 mm, for both streptomycin and gentamicin. No major or very major errors were found with either aminoglycoside using these values. We conclude that agar disk diffusion test can be used to accurately detect high-level or moderately high-level gentamicin and streptomycin resistance in E. faecium.

[Neonatal diseases with onset during fetal life. Clinical and etiopathogenetic considerations]

A modern definition is given of the perinatal period. The boundary between embryonal and foetal life is drawn to enable diseases than occur solely during the foetal period to be distinguished. Placental physiology, exchanges between mother and foetus and the general pathology of the foetus, with particular regard to immunological phenomena, are examined. An account is given of the carriage by the placenta of substances foreign to the body, the transplacental passage of drugs, and the permeability of the placenta to micro-organism. The several factors involved in this process are discussed. The effect of various micro-organisms on the foetus is illustrated. Modern views concerning the immunological position of the foetus are expounded and various situations where the foetus is at risk with respect to infection of the mother are considered.