Predicting Time to and Average Quality of Future Offers for Kidney Transplant Candidates Declining a Current Deceased Donor Kidney Offer: A Retrospective Cohort Study

Background

At the time a kidney offer is made by an organ donation organization (ODO), transplant physicians must inform candidates on the pros and cons of accepting or declining the offer. Although physicians have a general idea of expected wait time to kidney transplantation by blood group in their ODO, there are no tools that provide quantitative estimates based on the allocation score used and donor/candidate characteristics. This limits the shared decision-making process at the time of kidney offer as (1) the consequences of declining an offer in terms of wait-time prolongation cannot be provided and (2) the quality of the current offer cannot be compared with that of offers that could be made to the specific candidate in the future. This is especially relevant to older transplant candidates as many ODOs use some form of utility matching in their allocation score.

Objective

We aimed to develop a novel method to provide personalized estimates of wait time to next offer and quality of future offers for kidney transplant candidates if they refused a current deceased donor offer from an ODO.

Design

A retrospective cohort study.

Setting

Administrative data from Transplant Quebec.

Patients

All patients who were actively registered on the kidney transplant wait list at any point between March 29, 2012 and December 13, 2017.

Measurements

The time to next offer was defined as the number of days between the time of the current offer and the next offer if the current one were declined. The quality of the offers was measured with the 10-variable Kidney Donor Risk Index (KDRI) equation.

Methods

Candidate-specific kidney offer arrival was modeled with a marked Poisson process. To derive the lambda parameter for the marked Poisson process for each candidate, the arrival of donors was examined in the 2 years prior to the time of the current offer. The Transplant Quebec allocation score was calculated for each ABO-compatible offer with the characteristics that the candidate presented at the time of the current offer. Offers where the candidate's score was lower than the scores of actual recipients of the second kidneys transplanted were filtered out from the candidate-specific kidney offer arrival. The KDRIs of offers that remained were averaged to provide an estimate of the quality of future offers, to be compared with that of the current offer.

Results

During the study period, there were 848 unique donors and 1696 transplant candidates actively registered. The models provide the following information: average time to next offer, time to which there is a 95% probability of receiving a next offer, average KDRI of future offers. The C-index of the model was 0.72. When compared with providing average group estimates of wait time and KDRI of future offers, the model reduced the root-mean-square error in the predicted time to next offer from 137 to 84 days and that of predicted KDRI of future offers from 0.64 to 0.55. The precision of the model's predictions was higher when observed times to next offer were 5 months or less.

Limitations

The models assume that patients declining an offer remain wait-listed until the next one. The model only updates wait time every year after the time of an offer and not in a continuous fashion.

Conclusion

By providing personalized quantitative estimates of time to and quality of future offers, our new approach can inform the shared decision-making process between transplant candidates and physicians when a kidney offer from a deceased donor is made by an ODO.

GLUT1-DS Italian registry: past, present, and future: a useful tool for rare disorders

BACKGROUND

GLUT1 deficiency syndrome is a rare, genetically determined neurological disorder for which Ketogenic Dietary Treatment represents the gold standard and lifelong treatment. Patient registries are powerful tools providing insights and real-world data on rare diseases.

OBJECTIVE

To describe the implementation of a national web-based registry for GLUT1-DS.

METHODS

This is a retrospective and prospective, multicenter, observational registry developed in collaboration with the Italian GLUT1-DS association and based on an innovative, flexible and configurable cloud computing technology platform, structured according to the most rigorous requirements for the management of patient's sensitive data. The Glut1 Registry collects baseline and follow-up data on the patient's demographics, history, symptoms, genotype, clinical, and instrumental evaluations and therapies.

RESULTS

Five Centers in Italy joined the registry, and two more Centers are currently joining. In the first two years of running, data from 67 patients (40 females and 27 males) have been collected. Age at symptom onset was within the first year of life in most (40, 60%) patients. The diagnosis was formulated in infancy in almost half of the cases (34, 51%). Symptoms at onset were mainly paroxysmal (mostly epileptic seizure and paroxysmal ocular movement disorder) or mixed paroxysmal and fixed symptoms (mostly psychomotor delay). Most patients (53, 79%) are currently under Ketogenic dietary treatments.

CONCLUSIONS

We describe the principles behind the design, development, and deployment of the web-based nationwide GLUT1-DS registry. It represents a stepping stone towards a more comprehensive understanding of the disease from onset to adulthood. It also represents a virtuous model from a technical, legal, and organizational point of view, thus representing a possible paradigmatic example for other rare disease registry implementation.

The promise of machine learning applications in solid organ transplantation

Solid-organ transplantation is a life-saving treatment for end-stage organ disease in highly selected patients. Alongside the tremendous progress in the last several decades, new challenges have emerged. The growing disparity between organ demand and supply requires optimal patient/donor selection and matching. Improvements in long-term graft and patient survival require data-driven diagnosis and management of post-transplant complications. The growing abundance of clinical, genetic, radiologic, and metabolic data in transplantation has led to increasing interest in applying machine-learning (ML) tools that can uncover hidden patterns in large datasets. ML algorithms have been applied in predictive modeling of waitlist mortality, donor–recipient matching, survival prediction, post-transplant complications diagnosis, and prediction, aiming to optimize immunosuppression and management. In this review, we provide insight into the various applications of ML in transplant medicine, why these were used to evaluate a specific clinical question, and the potential of ML to transform the care of transplant recipients. 36 articles were selected after a comprehensive search of the following databases: Ovid MEDLINE; Ovid MEDLINE Epub Ahead of Print and In-Process & Other Non-Indexed Citations; Ovid Embase; Cochrane Database of Systematic Reviews (Ovid); and Cochrane Central Register of Controlled Trials (Ovid). In summary, these studies showed that ML techniques hold great potential to improve the outcome of transplant recipients. Future work is required to improve the interpretability of these algorithms, ensure generalizability through larger-scale external validation, and establishment of infrastructure to permit clinical integration.

Morphological and Functional Evaluation of Isolated Rat Hepatocytes in three Dimensional Culture Systems

Various three-dimensional configurations, such as polyester tissue and woven-nonwoven, hydrophilic polyester fabric, either collagen-coated or uncoated, were investigated as potential scaffold for hepatocyte culture, in view of their use in bioreactors for hybrid liver support systems. Attachment, morphology and ultrastructure of primary adult rat hepatocytes were evaluated, as well as urea production and ammonium detoxification during a 24h incubation period in serum-free tissue culture medium. As control, hepatocytes were also plated onto collagen-coated dextran microcarriers and on plastic petri dishes, either collagen-coated or uncoated. In all the three-dimensional cultures, hepatocytes appeared morphologically intact without any statistically significant difference in metabolic activity. Collagen-coating did not influence cell attachment to polyester substrates, whereas woven-nonwoven hydrophilic polyester fabric may offer some potential advantages as three-dimensional system for hepatocyte culture in hybrid liver support systems.

Design of an Irreversible Electroporation System for Clinical Use

Irreversible electroporation is an ablation modality in which microseconds, high-voltage electrical pulses are applied to induce cell necrosis in a target tissue. To perform irreversible electroporation it is necessary to use a medical device specifically designed for this use.

The design of an irreversible electroporation system is a complex task in which the effective delivery of high energy pulses and the safety of the patient and operator are equally important. Pulses of up to 3000 V of amplitude and 50 A of current need to be generated to irreversibly electroporate a target volume of approximately 50 to 70 cm3 with as many as six separate electrodes; therefore, a traditional approach based on high voltage amplifiers becomes hard to implement.

In this paper, we present the process that led to the first irreversible electroporator capable of such performances approved for clinical use. The main design choices and its architecture are outlined. Safety issues are also explained along with the solutions adopted.

Forecasting future needs and optimal allocation of medical residency positions: the Emilia-Romagna Region case study

OBJECTIVES

Italian regional health authorities annually negotiate the number of residency grants to be financed by the National government and the number and mix of supplementary grants to be funded by the regional budget. This study provides regional decision-makers with a requirement model to forecast the future demand of specialists at the regional level.

METHODS

We have developed a system dynamics (SD) model that projects the evolution of the supply of medical specialists and three demand scenarios across the planning horizon (2030). Demand scenarios account for different drivers: demography, service utilization rates (ambulatory care and hospital discharges) and hospital beds. Based on the SD outputs (occupational and training gaps), a mixed integer programming (MIP) model computes potentially effective assignments of medical specialization grants for each year of the projection.

RESULTS

To simulate the allocation of grants, we have compared how regional and national grants can be managed in order to reduce future gaps with respect to current training patterns. The allocation of 25 supplementary grants per year does not appear as effective in reducing expected occupational gaps as the re-modulation of all regional training vacancies.

Determination of the purity of valine by isocratic liquid chromatography coupled with charged aerosol detection (CAD)

A liquid chromatography coupled with charged aerosol detection (LC-CAD) procedure; capable of separating and quantifying the most common impurities of valine at levels as low as 0.05 per cent (m/m), has been developed. The procedure is simple (isocratic), rapid, linear, sensitive and repeatable. It employs a widely available and inexpensive stationary phase (C18).

Choline kinase inhibition in rheumatoid arthritis

OBJECTIVES

Little is known about targeting the metabolome in non-cancer conditions. Choline kinase (ChoKα), an essential enzyme for phosphatidylcholine biosynthesis, is required for cell proliferation and has been implicated in cancer invasiveness. Aggressive behaviour of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA) led us to evaluate whether this metabolic pathway could play a role in RA FLS function and joint damage.

METHODS

Choline metabolic profile of FLS cells was determined by (1)H magnetic resonance spectroscopy ((1)HMRS) under conditions of ChoKα inhibition. FLS function was evaluated using the ChoKα inhibitor MN58b (IC₅₀=4.2 μM). For arthritis experiments, mice were injected with K/BxN sera. MN58b (3 mg/kg) was injected daily intraperitoneal beginning on day 0 or day 4 after serum administration.

RESULTS

The enzyme is expressed in synovial tissue and in cultured RA FLS. Tumour necrosis factor (TNF) and platelet-derived growth factor (PDGF) stimulation increased ChoKα expression and levels of phosphocholine in FLS measured by Western Blot (WB) and metabolomic studies of choline-containing compounds in cultured RA FLS extracts respectively, suggesting activation of this pathway in RA synovial environment. A ChoKα inhibitor also suppressed the behaviour of cultured FLS, including cell migration and resistance to apoptosis, which might contribute to cartilage destruction in RA. In a passive K/BxN arthritis model, pharmacologic ChoKα inhibition significantly decreased arthritis in pretreatment protocols as well as in established disease.

CONCLUSIONS

These data suggest that ChoKα inhibition could be an effective strategy in inflammatory arthritis. It also suggests that targeting the metabolome can be a new treatment strategy in non-cancer conditions.

Determination of water content by capillary gas chromatography coupled with thermal conductivity detection

This article presents some experience obtained by applying capillary gas chromatography coupled with thermal conductivity detection (GC/TCD) to the determination of water in substances for pharmaceutical use. This technique represents a useful, orthogonal tool complementary to water determination methods based on volumetric or coulometric titration. It can also represent an alternative technique when such titrations are not applicable. This article presents the preliminary results obtained in a number of case studies where a GC/TCD procedure was applied in comparison with pharmacopoeial methods to substances with different water contents.

Biogas production and valorization by means of a two-step biological process

The scope of this research work was to investigate biogas production and purification by a two-step bench-scale biological system, consisting of fed-batch pulse-feeding anaerobic digestion of mixed sludge, followed by methane enrichment of biogas by the use of the cyanobacterium Arthrospiraplatensis. The composition of biogas was nearly constant, and methane and carbon dioxide percentages ranged between 70.5-76.0% and 13.2-19.5%, respectively. Biogas yield reached a maximum value (about 0.4 m(3)(biogas)/kg COD(i)) at 50 days-retention time and then gradually decreased with a decrease in the retention time. Biogas CO(2) was then used as a carbon source for A. platensis cultivation either under batch or fed-batch conditions. The mean cell productivity of fed-batch cultivation was about 15% higher than that observed during the last batch phase (0.035+/-0.006 g(DM)/L/d), likely due to the occurrence of some shading effect under batch growth conditions. The data of carbon dioxide removal from biogas revealed the existence of a linear relationship between the rates of A. platensis growth and carbon dioxide removal from biogas and allowed calculating carbon utilization efficiency for biomass production of almost 95%.

An unusual bilateral areolar dermatitis

This article describes an uncommon clinical manifestation of contact dermatitis due to dyed tissues, showing bilateral plaque lesions on the mammary areolas. The clinical history, histological and patch testing examinations confirmed the diagnosis. The possible triggering factors related with this kind of contact dermatitis and possible differential diagnosis are briefly discussed.

Cadmium biosorption on Spirulina platensis biomass

Dry biomass of Spirulina platensis re-hydrated for 48 h was employed as a biosorbent in tests of cadmium(II) removal from water. Various concentrations of biomass (from 1 to 4 g l(-1)) and metal (from 100 to 800 mg l(-1)) were tested. Low biomass levels (X(o)2 g l(-1)) ensured metal removal up to 98% only at Cd(0)= 100 and 200 mg l(-1), while X(o)2.0 g l(-1) were needed at Cd(0)=400 mg l(-1) to achieve satisfactory results. Whereas X(o)=4.0 g l(-1) was effective to remove up to Cd(0)=500 mg l(-1), a further increase in metal concentration (Cd(0)=600 and 800 mg l(-1)) led to progressive worsening of the system performance. At a given biomass levels, the kinetics of the process was better at low Cd(2+) concentrations, while, raising the adsorbent level from 1.0 to 2.0 g l(-1) and then to 4.0 g l(-1), the rate constant of biosorption increased by about one order of magnitude in both cases and the adsorption capacity of the system progressively decreased from 357 to 149 mg g(-1).

The evolution of the pharmacopoeial test for heavy metals

This article describes some recent improvements to simplify the test for heavy metals, avoiding loss of analytes and increasing sensitivity.

Inter-laboratory reproducibility of the LC-ELSD method for the control of composition of sesame oil recently introduced in the Ph. Eur

Evaporative light-scattering detection (ELSD) is an increasingly important technology for the control of substances for pharmaceutical use. A LC-ELSD method has recently been introduced in the Ph. Eur. monograph for sesame oil, refined to control the composition of triglycerides. A collaborative study was run to assess the reproducibility of the new method and to confirm that it was suitable for pharmacopoeial use.

A liquid chromatographic method using a reversed-phase hybrid stationary phase to control potential impurities of imipramine hydrochloride

A reversed-phase liquid chromatographic method has been developed for the detection and control of impurities of imipramine hydrochloride at a level of 0.2 microg/ml (corresponding to 0.02 per cent in the procedure described). This method is included in a proposed revision of the monograph (Pharmeuropa 18.4) and replaces the thin-layer chromatographic method currently employed.

Copper removal by dry and re-hydrated biomass of Spirulina platensis

Dried and re-hydrated biomass of Spirulina platensis was employed as a sorbent in tests of copper removal from water. Biomass re-hydrated for 24 h before use exhibited a shorter adsorption time as well as an increased percentage removal when compared with simply dried biomass. The combined effects of the concentrations of re-hydrated biomass (from 1.0 to 4.0 g l-1) and copper (from 0.1 to 0.4 g l-1) were then investigated. Copper was almost entirely removed (91% removal) at relatively high biomass levels (X0>or=2.0 gDM l-1), while 1.0 gDM l-1 removed only 81% of copper present initially, suggesting a situation of excess metal with respect to the adsorption capacity of biomass. Additional tests performed with biomass re-hydrated for variable time demonstrated that no less than 48 h of this treatment are needed to ensure a satisfactory copper removal, while no significant improvement was detected using biomass re-hydrated for longer times.

Evaporative light scattering detection (ELSD): a tool for improved quality control of drug substances

Thanks to the recent technological advancements, evaporative light-scattering detection (ELSD) is regarded as a valuable alternative to UV detection for liquid chromatographic analysis of substances that do not contain a chromophore. In the field of substances for pharmaceutical use, LC-ELSD appears to be suitable for aminoglycosides, most of which (for ex. gentamicin) are presently controlled in the Ph. Eur. by pulsed amperometric detection. Other substances (ex sugars, triglycerides) presently employing refractometrric detection, could be conveniently analysed by LC-ELSD. ELS detection is regarded as robust and relatively simple, although not particularly sensitive. A key feature of ELSD is that - unlike refractometry - it can operate in gradient mode, thus allowing application of more selective liquid chromatographic methods. ELSD can also be used to set up MS-compatible methods, as the mobile phase constraints are essentially the same. Due to all the above, ELSD is becoming increasingly used in pharmacopoeial methods.

Ammonium and urea removal by Spirulina platensis

Different concentrations either of ammonium chloride or urea were used in batch and fed-batch cultivations of Spirulina platensis to evaluate the possibility of substituting nitrate by cheaper reduced nitrogen sources in wastewaters biotreatment. The maximum nitrogen concentration able to sustain the batch growth of this microalga without inhibition was 1.7 mM in both cases. Ammonium chloride was limiting for the growth at lower concentrations, whereas inhibition took place at higher levels. This inhibition effect was less marked with urea, likely because the enzymatic hydrolysis of this compound by urease controlled the ammonia transfer into the cell. Fed-batch experiments carried out by pulse-feeding either ammonium or urea proved that the use of these compounds as nitrogen sources can sustain the long term-cultivation of S. platensis, provided that the conditions for their feeding are accurately optimized.

The control of impurities in amitriptyline hydrochloride using a reversed-phase hybrid stationary phase

An isocratic reversed-phase liquid chromatographic method is described using a hybrid column for the control of synthetic impurities potentially found in amitriptyline hydrochloride. The method has been validated and is capable of controlling impurities to 0.1 per cent.

The control of impurities in chlortalidone using a reversed-phase stationary phase

A reversed-phased liquid chromatographic method for the control of impurities of nine impurities in Chlortalidone drug substance is presented. The method is sufficiently sensitive to quantify down to the level of 0.0015 per cent equivalent to a concentration of 15 microg/ml.

Nitrate and phosphate removal by Spirulina platensis

The cyanobacterium Spirulina platensis was used to verify the possibility of employing microalgal biomass to reduce the contents of nitrate and phosphate in wastewaters. Batch tests were carried out in 0.5 dm3 Erlenmeyer flasks under conditions of light limitation (40 micromol quanta m(-2) s(-1)) at a starting biomass level of 0.50 g/dm3 and varying temperature in the range 23-40 degrees C. In this way, the best temperature for the growth of this microalga (30 degrees C) was determined and the related thermodynamic parameters were estimated. All removed nitrate was used for biomass growth (biotic removal), whereas phosphate appeared to be removed mainly by chemical precipitation (abiotic removal). The best results in terms of specific and volumetric growth rates (mu=0.044 day(-1), Qx=33.2 mg dm(-3) day(-1)) as well as volumetric rate and final yield of nitrogen removal (Q(N-NO3-)=3.26 mg dm(-3) day(-1), Y(N-NO3-)=0.739) were obtained at 30 degrees C, whereas phosphorus was more effectively removed at a lower temperature. In order to simulate full-scale studies, batch tests of nitrate and phosphate removal were also performed in 5.0 dm3 vessels (mini-ponds) at the optimum temperature (30 degrees C) but increasing the photon fluence rate to 80 micromol quanta m(-2) s(-1) and varying the initial biomass concentration from 0.25 to 0.86 g/dm3. These additional tests demonstrated that an increase in the inoculum level up to 0.75 g/dm3 enhanced both NO3- and PO4(3-) removal, confirming a strict dependence of these processes on biomass activity. In addition, the larger surface area of the ponds and the higher light intensity improved removal yields and kinetics compared to the flasks, particularly concerning phosphorus removal (mu=0.032-0.050 day(-1), Qx=34.7-42.4 mg dm(-3) day(-1), Q(N-NO3-)=3.24-4.06 mg dm(-3) day(-1), Y(N-NO3-)=0.750-0.879, Q(P-PO4(3-))=0.312-0.623 mg dm(-3) day(-1), and Y(P-PO4(3-))=0.224-0.440).

The control of nitrilotriacetic acid in edetic acid and its salts by liquid chromatography

Two liquid chromatographic methods have been developed and validated for the determination of nitrilotriacetic acid (NTA) in edetic acid (EDTA) and its salts. In one method NTA and EDTA are separated on a polymer column without pretreatment, and are detected amperometrically using a glassy-carbon electrode. In the other method NTA and EDTA are complexed with ferric ions and the complexes separated on a porous graphite carbon stationary phase with ultraviolet detection at 215 nm. Both methods were sufficiently selected and sensitive to allow the control of NTA (0.1% m/m) in sample of EDTA and its salts.

Bioleaching of zinc and aluminium from industrial waste sludges by means of Thiobacillus ferrooxidans

Biological solubilisation of heavy metals contained in two different kinds of industrial wastes was performed in batches employing a strain of Thiobacillus ferroxidans. The wastes tested were: a dust coming from the iron-manganese alloy production in an electric furnace (sludge 1) and a sludge coming from a process treatment plant of aluminium anodic oxidation (sludge 2). The experimental results pointed out the ability of the used strain to maintain the environment, that initially has a pH about 8, at strongly acid conditions (pH 2.5-3.5), producing sulphuric acid that is the chemical agent responsible for the metals solubilisation. At wastes initial concentration of 1%, the percentage of solubilised metals was 76 and 78% for the wastes 1 and 2, respectively, but the lag phase was considerably longer for sludge 2 than for sludge 1, indicating a different affinity of microorganisms for the solid phase. Increasing the initial slurry concentration, the percentage of removed metal reached 72-73% for the sludge 1, while in case of sludge 2, the total amount of solubilized metal progressively decreased. Two kinetic models are proposed to describe the trends of metals solubilization curves.

Treatment of effluent containing micropollutants by means of activated carbon

Different amounts of granular activated carbon (GAC) have been tested for the removal of aliphatic and aromatic micropollutants contained in a liquid stream coming from an industrial plant. Tests have been carried out in a JAR-Test apparatus, using plugged flasks, in order to eliminate the oxygen influence on the adsorption process and to obtain information for studying the process in a pilot plant. The removal of aliphatic compounds resulted better than aromatic ones, probably because these substances are enveloped by water molecules which make adsorption on the GAC surface easier; in contrast, aromatic compounds show a lower affinity for the GAC, owing to their steric conformation. The good results obtained confirm that the proposed system is applicable to the examined effluent, even when the concentration of the pollutant load varies. In the latest part of this work, a plan for the construction of a full-scale plant to treat the examined wastewater has been developed.

Epidemiology of occupational contact dermatitis in a North Italian population

Occupational contact dermatitis (OCD) is a very important skin disease both for its high frequency and for its social and economic implications. The aim of our work is to evaluate the epidemiology of occupational contact dermatitis in a north-Italian population and the possibility of a correct etiological diagnosis using the patch test standard series of GIRDCA (Italian Group of Resarch on Contact Dermatitis). We patch tested 1,565 out-patients affected by dermatitis with standard series GIRDCA and with other specific professional haptens. The manifestations were suspected of being of occupational origin by a dermatologist on the basis of clinical and anamnestic data. Of all the recorded professions we have considered only the more numerically significant: food industry, building industry, textile industry, employees, cleaners, hospital personnel, hairdressers, housewives, mechanics and metallurgists. Sixty-nine percent of contact dermatitis was found in women, the hairdressers had the greatest number of patients in the younger group (68.7% in the 11-20 years age group) and the textile industry workers in older group (100% in the 41-50 years age group). A positive allergological anamnesis emerged in 32.3% of allergic contact dermatitis. Irritant contact dermatitis (10.6%) was more frequent than allergic contact dermatitis (8.4%). The hands are the most common localization (94. 4%). The allergen with the highest frequency of positive reactions is p-phenylenediamine (25.3%). We discuss the frequency of positives to various groups of allergens in each profession and the principal means of contact. Because of the frequency of this type of occupational skin disease, we stress the importance of prevention. The standard series GIRDCA was found to be adequate for recognizing occupational contact dermatitis in most of our patients (74%).

Morphological and functional evaluation of isolated rat hepatocytes in three dimensional culture systems

Various three-dimensional configurations, such as polyester tissue and woven-nonwoven, hydrophilic polyester fabric, either collagen-coated or uncoated, were investigated as potential scaffold for hepatocyte culture, in view of their use in bioreactors for hybrid liver support systems. Attachment, morphology and ultrastructure of primary adult rat hepatocytes were evaluated, as well as urea production and ammonium detoxification during a 24h incubation period in serum-free tissue culture medium. As control, hepatocytes were also plated onto collagen-coated dextran microcarriers and on plastic petri dishes, either collagen-coated or uncoated. In all the three-dimensional cultures, hepatocytes appeared morphologically intact without any statistically significant difference in metabolic activity. Collagen-coating did not influence cell attachment to polyester substrates, whereas woven-nonwoven hydrophilic polyester fabric may offer some potential advantages as three-dimensional system for hepatocyte culture in hybrid liver support systems.

Relationship between intrathyroid calcifications and thyroglobulin in endemic goiter

Intrathyroid calcifications represent a common finding within simple or nodular goiters, but, as far as they can be found also inside papillary and medullary thyroid carcinomas, an ultrasonographic detection of intrathyroid calcifications stands as a different diagnosis problem. We have been looking for the presence of parameters associated with thyroid calcifications in patients affected by simple or nodular goiter, either sporadic or endemic. We studied 284 euthyroid subjects, 250 females, ageing from 24 to 90 years, affected by a simple goiter, in the 9.51% of the cases, and by a nodular goiter in the remaining part. 69.37% of the patients came from an endemic goiter area, while the others were affected by sporadic goiter. We tested fT3, fT4, TSH, hTG, Ab-TG, Ab-TPO and performed an ultrasonography in all the subjects, 57.75% of patients shown intrathyroid calcifications in the 57.75% of them. We applied a multistep discriminant analysis taking for the presence/absence of calcifications as dependent variable and we tried to find which variable, by itself or in combination with others, could foretell its presence. We also created a new variable (TG1) to differentiate normal from supraphysiologic concentrations of hTG (< 60 ng/ml). The variable with the highest significance F originated from endemic goiter area (F = 96.36), followed by TG1 (F = 24.46) and age (F = 10.61). On the contrary hTG did not relate to calcifications, due to non-proportionally direct relationship between these two parameters, afterwards we used the multistep logistic regression that gave overlapping significances. This means that supraphysiologic hTG rates are sufficient to predict the possible presence of intrathyroid calcifications. In conclusion, as far as a follicular hyperstimulation can be assumed, especially if long-lasting, the presence of intrathyroid calcifications should rise a clinical suspect toward an old goiter rather than a neoplastic lesion.

In vitro stability of polymerase chain reaction-generated DNA fragments in serum and cell extracts

The potential use of polymerase chain reaction (PCR)-generated DNA fragments (PCR-DNAs) as pharmaceutical agents has previously been suggested, with the demonstration of the in vitro cellular internalization and biologic activity of PCR-DNA decoy molecules targeted to human estrogen receptor gene. In order to provide information on the stability of these double-stranded DNA molecules, the nuclease resistance of PCR-DNAs of different sizes was studied in different conditions and experiments. Simulating in vitro and in vivo transfection protocol, we demonstrated that PCR-DNAs exhibited good stability toward fetal bovine serum (FBS) and adult human serum nuclease digestion. In addition, when the protective activity of liposome-based formulations toward nuclease digestion was tested, it was shown that the stability of PCR-DNAs could be further increased (up to 7 days) when a liposome-mediated delivery system was employed.