Complications of lumboperitoneal shunts. A retrospective study of a series of 195 patients (214 procedures)

BACKGROUND AND PURPOSE: We report our experience with the lumboperitoneal shunt (LPS) in 195 patients. The aim of this retrospective study was to assess and compare the rate of complications and to discuss 4 indications. MATERIAL AND METHOD: Between January 1983 and July 1994, 195 patients including 14 pediatric cases were treated with a LPS. Sex ratio was 1.24. The mean age at insertion was 59.5 years (from 6 months to 88 years) and the follow-up in this series was from 6 months to 12.5 years. The indications for a LPS were: chronic idiopathic hydrocephalus (115 cases), post-hemorrhagic hydrocephalus (37 cases), cerebrospinal fluid fistula (11 cases), post-traumatic hydrocephalus (9 cases), post-surgical hydrocephalus (8 cases), hydrocephalus of the child (6 cases), post-meningitis hydrocephalus (4 cases), benign intracranial hypertension (4 cases), post-radiotherapy hydrocephalus (1). Forty patients (20.5%) presented with at least one complication. A total of 47 complications were observed: chronic subdural effusion (8 cases), meningitis (10 cases), mechanical failures (28 cases), acquired Chiari abnormality (1 case). Mechanical complications varied with the type of shunt. CONCLUSION: Complications of LPS in adults are less frequent than is usually reported after ventricular atrial or peritoneal shunting. In adults, LPS can be used as the first valuable treatment in case of chronic communicating hydrocephalus. LPS is also valuable in the treatment of benign intracranial hypertension or recurrent CSF fistulae. Conversely, in the pediatric cases general and specific complications are frequent, so an indication for LPS must be strictly discussed.     

Locating interesting geothermal areas in the Tuscany Region (Italy) by geochemical and isotopic methods

In the western and central part of Siena province some zones have been individuated for the first time as being of considerable interest to geothermal fluid research.Geochemical prospecting on the thermal manifestations in this area has permitted the delimitation of the zones where the Na-K-Ca ratio reveals high underground temperatures. On the other hand isotopic analyses show that, in these same localities, there is an isotopic exchange between the oxygen of the water and that of the rocks. This exchange has previously been noted in geothermal fluids.These observations lead to the conclusion that the thermal manifestations under study, which also seem to be situated where there are important basement fractures, are the result of a mixing of geothermal steam condensate and the shallow circulation waters.     

A procedure for assessing the functional reliability of hospital systems

An effective reliability-based procedure is presented to assess the capability of hospitals to be functional after a seismic event of a given intensity. Every major function in a hospital depends on the joint action of various cooperating services, which in turn are made up from a certain number of sub-services. Such a complex organization is described in terms of a logical scheme and subsequently reduced to a minimal cut-set representation. For each sub-service a collapse criterion is defined, by which the strength is compared to the action load, both represented as random variables. Strengths are evaluated through assessment analyses based on design drawings. Loads are evaluated from 3-D linear dynamic analyses under seismic input. This is given by the Eurocode 8 elastic response spectrum, scaled at a given peak ground acceleration and account for the position of the sub-service within the building. By calculating the failure probability of each service by FORM (First Order Reliability Method) or SORM (Second Order Reliability Methods), the probability of functional interruption is obtained in terms of Didevsen bounds, conditional on a given earthquake intensity. The method helps to single out weak elements and potential sources of damage (structural, non-structural, equipment) within the hospital. This allows: (a) to investigate quantitatively the effectiveness of different upgrading criteria, (b) to select rationally intervention hypotheses, both in the retrofitting and rehabilitation of existing hospitals and in the design optimization of new ones, and (c) to evaluate different investment options for seismic vulnerability mitigation. As an example, an application to a case study hospital is presented.     

Network Analysis of Gut Microbiome and Metabolome to Discover Microbiota-Linked Biomarkers in Patients Affected by Non-Small Cell Lung Cancer

Several studies in recent times have linked gut microbiome (GM) diversity to the pathogenesis of cancer and its role in disease progression through immune response, inflammation and metabolism modulation. This study focused on the use of network analysis and weighted gene co-expression network analysis (WGCNA) to identify the biological interaction between the gut ecosystem and its metabolites that could impact the immunotherapy response in non-small cell lung cancer (NSCLC) patients undergoing second-line treatment with anti-PD1. Metabolomic data were merged with operational taxonomic units (OTUs) from 16S RNA-targeted metagenomics and classified by chemometric models. The traits considered for the analyses were: (i) condition: disease or control (CTRLs), and (ii) treatment: responder (R) or non-responder (NR). Network analysis indicated that indole and its derivatives, aldehydes and alcohols could play a signaling role in GM functionality. WGCNA generated, instead, strong correlations between short-chain fatty acids (SCFAs) and a healthy GM. Furthermore, commensal bacteria such as Akkermansia muciniphila, Rikenellaceae, Bacteroides, Peptostreptococcaceae, Mogibacteriaceae and Clostridiaceae were found to be more abundant in CTRLs than in NSCLC patients. Our preliminary study demonstrates that the discovery of microbiota-linked biomarkers could provide an indication on the road towards personalized management of NSCLC patients.     

Unraveling Structural Information of Turkevich Synthesized Plasmonic Gold–Silver Bimetallic Nanoparticles

For the synthesis of gold–silver bimetallic nanoparticles, the Turkevich method has been the state‐of‐the‐art method for several decades. It is presumed that this procedure results in a homogeneous alloy, although this has been debatable for many years. In this work, it is shown that neither a full alloy, nor a perfect core–shell particle is formed but rather a core–shell‐like particle with altering metal composition along the radial direction. In‐depth wet‐chemical experiments are performed in combination with advanced transmission electron microscopy, including energy‐dispersive X‐ray tomography, and finite element method modeling to support the observations. From the electron tomography results, the core–shell structure can be clearly visualized and the spatial distribution of gold and silver atoms can be quantified. Theoretical simulations are performed to demonstrate that even though UV–vis spectra show only one plasmon band, this still originates from core–shell type structures. The simulations also indicate that the core–shell morphology does not so much affect the location of the plasmon band, but mainly results in significant band broadening. Wet‐chemistry experiments provide the evidence that the synthesis pathway starts with gold enriched alloy cores, and later on in the synthesis mainly silver is incorporated to end up with a silver enriched alloy shell.     

Selective Capture of Anti-N-glucosylated NTHi Adhesin Peptide Antibodies by a Multivalent Dextran Conjugate

Tentacle-like polymers decorated with several copies of peptide antigens can be interesting tools for increasing the ability to capture circulating antibodies in patient sera, using cooperative effects for stronger avidity. We previously showed that antibodies from multiple sclerosis (MS) patient sera preferentially recognize hyperglucosylated adhesin protein HMW1ct of non-typeable Haemophilus influenzae (NTHi). We selected the C-terminal HMW1ct(1347–1354) minimal epitope and prepared the diglucosylated analogue Ac-KAN(Glc)VTLN(Glc)TTG-K(N₃)-NH₂ to graft a 40 kDa dextran scaffold modified with glycidyl-propargyl moieties to perform a copper catalyzed alkyne-azide coupling reaction (CuAAC). Quantitative NMR measurements allowed the characterization of the peptide loading (19.5 %) on the multivalent dextran conjugate. This novel polymeric structure displayed optimal capturing properties of both IgG and, more interestingly, IgM antibodies in MS sera. Specific antibodies from a representative MS serum, were successfully depleted using a Sepharose resin bearing the new glucosylated multivalent conjugate, as confirmed by ELISA. These results may offer a promising proof-of-concept for the selective purification of high affinity autoantibodies from sera of autoimmune patients, in general, and of specific high affinity antibodies against a minimally glcosylated epitope Asn(Glc) from sera of multiple sclerosis (MS) patients, in particular.