Molecular nanomagnets: a viable path toward quantum information processing?

Molecular nanomagnets (MNMs), molecules containing interacting spins, have been a playground for quantum mechanics. They are characterized by many accessible low-energy levels that can be exploited to store and process quantum information. This naturally opens the possibility of using them as qudits, thus enlarging the tools of quantum logic with respect to qubit-based architectures. These additional degrees of freedom recently prompted the proposal for encoding qubits with embedded quantum error correction (QEC) in single molecules. QEC is the holy grail of quantum computing and this qudit approach could circumvent the large overhead of physical qubits typical of standard multi-qubit codes. Another important strength of the molecular approach is the extremely high degree of control achieved in preparing complex supramolecular structures where individual qudits are linked preserving their individual properties and coherence. This is particularly relevant for building quantum simulators, controllable systems able to mimic the dynamics of other quantum objects. The use of MNMs for quantum information processing is a rapidly evolving field which still requires to be fully experimentally explored. The key issues to be settled are related to scaling up the number of qudits/qubits and their individual addressing. Several promising possibilities are being intensively explored, ranging from the use of single-molecule transistors or superconducting devices to optical readout techniques. Moreover, new tools from chemistry could be also at hand, like the chiral-induced spin selectivity. In this paper, we will review the present status of this interdisciplinary research field, discuss the open challenges and envisioned solution paths which could finally unleash the very large potential of molecular spins for quantum technologies.

Burden of phenylketonuria in Latin American patients: a systematic review and meta-analysis of observational studies

Background

Phenylketonuria (PKU) is an inborn error of metabolism caused by a deficiency of the enzyme phenylalanine hydroxylase. If untreated, the complications of PKU lead to significant neucognitive and neuropsychiatric impairments, placing a burden on both the individual’s quality of life and on the healthcare system. We conducted a systematic literature review to characterize the impact of PKU on affected individuals and on healthcare resources in Latin American (LATAM) countries.

Methods

Searches of the global medical literature as well as regional and local medical literature up to September 2021. Observational studies on patients with PKU from any LATAM country. Pairs of reviewers independently screened eligible articles, extracted data from included studies, and assessed their risk of bias.

Results

79 unique studies (47 cross-sectional studies, 18 case series, 12 case reports, and two cohort studies) with a total of 4090 patients were eligible. Of these studies, 20 had data available evaluating early-diagnosed PKU patients for meta-analysis of burden outcomes. Intellectual disability in the pooled studies was 18% [95% Confidence Interval (CI) 0.04–0.38; I² = 83.7%, p = 0.0133; two studies; n = 114]. Motor delay was 15% [95% CI 0.04–0.30; I² = 74.5%, p = 0.0083; four studies; n = 132]. Speech deficit was 35% [95% CI 0.08–0.68; I² = 93.9%, p < 0.0001; five studies; n = 162].

Conclusions

There is currently evidence of high clinical burden in PKU patients in LATAM countries. Recognition that there are many unmet neuropsychological needs and socioeconomic challenges faced in the LATAM countries is the first step in planning cost-effective interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02450-2.

Theoretical Design of Optimal Molecular Qudits for Quantum Error Correction

We pinpoint the key ingredients ruling decoherence in multispin clusters, and we engineer the system Hamiltonian to design optimal molecules embedding quantum error correction. These are antiferromagnetically coupled systems with competing exchange interactions, characterized by many low-energy states in which decoherence is dramatically suppressed and does not increase with the system size. This feature allows us to derive optimized code words, enhancing the power of the quantum error correction code by orders of magnitude. We demonstrate this by a complete simulation of the system dynamics, including the effect of decoherence driven by a nuclear spin bath and the full sequence of pulses to implement error correction and logical gates between protected states.

Assessing the Nature of Chiral-Induced Spin Selectivity by Magnetic Resonance

Understanding chiral-induced spin selectivity (CISS), resulting from charge transport through helical systems, has recently inspired many experimental and theoretical efforts but is still the object of intense debate. In order to assess the nature of CISS, we propose to focus on electron-transfer processes occurring at the single-molecule level. We design simple magnetic resonance experiments, exploiting a qubit as a highly sensitive and coherent magnetic sensor, to provide clear signatures of the acceptor polarization. Moreover, we show that information could even be obtained from time-resolved electron paramagnetic resonance experiments on a randomly oriented solution of molecules. The proposed experiments will unveil the role of chiral linkers in electron transfer and could also be exploited for quantum computing applications.

Erratum: Many-Body Models for Molecular Nanomagnets [Phys. Rev. Lett. 110, 157204 (2013)]

This corrects the article DOI: 10.1103/PhysRevLett.110.157204.

Molecular Nanomagnets as Qubits with Embedded Quantum-Error Correction

We show that molecular nanomagnets have a potential advantage in the crucial rush toward quantum computers. Indeed, the sizable number of accessible low-energy states of these systems can be exploited to define qubits with embedded quantum error correction. We derive the scheme to achieve this crucial objective and the corresponding sequence of microwave/radiofrequency pulses needed for the error correction procedure. The effectiveness of our approach is shown already with a minimal S = 3/2 unit corresponding to an existing molecule, and the scaling to larger spin systems is quantitatively analyzed.

Molecular Nanomagnets as Qubits with Embedded Quantum-Error Correction

We show that molecular nanomagnets have a potential advantage in the crucial rush toward quantum computers. Indeed, the sizable number of accessible low-energy states of these systems can be exploited to define qubits with embedded quantum error correction. We derive the scheme to achieve this crucial objective and the corresponding sequence of microwave/radiofrequency pulses needed for the error correction procedure. The effectiveness of our approach is shown already with a minimal S = 3/2 unit corresponding to an existing molecule, and the scaling to larger spin systems is quantitatively analyzed.

DARR: A Free-text Analysis System for the Automatic Documentation of Radiological Reports

A software system for the automatic free-text analysis and retrieval of radiological reports is presented. Such software involves: (1) automatic translation of the specific natural language in a formalized metalanguage in order to transform the radiological report in a »normalized report« analyzable by computer; (2) content processing of the normalized report to select desired information. The approach used to accomplish point (1) is described in detail referring to a specific application.

Magnetic Exchange Interactions in the Molecular Nanomagnet Mn_{12}

The discovery of magnetic bistability in Mn_{12} more than 20 years ago marked the birth of molecular magnetism, an extremely fertile interdisciplinary field and a powerful route to create tailored magnetic nanostructures. However, the difficulty to determine interactions in complex polycentric molecules often prevents their understanding. Mn_{12} is an outstanding example of this difficulty: although it is the forefather and most studied of all molecular nanomagnets, an unambiguous determination of even the leading magnetic exchange interactions is still lacking. Here we exploit four-dimensional inelastic neutron scattering to portray how individual spins fluctuate around the magnetic ground state, thus fixing the exchange couplings of Mn_{12} for the first time. Our results demonstrate the power of four-dimensional inelastic neutron scattering as an unrivaled tool to characterize magnetic clusters.

Impact of resection margin status on oncological outcomes after CO2 laser cordectomy

The management of positive resection margins in micro-endoscopic glottic laser surgery remains a controversial and critical point. This study aims to assess the impact of margin status after transoral laser surgery on local control, survival and organ preservation rates; the decision-making process and treatment options in cases with positive margins are also discussed. We retrospectively reviewed the clinical and histological records of 308 consecutive patients with primary early glottic carcinoma (T1a, T1b, selected T2) and treated with endoscopic laser cordectomy. Recurrence rates and survival related to margin status were analysed using the Kaplan-Meier method. Local relapses and disease-free-survival rates were significantly related to excision margin status (p < 0.001). In the T1a category (n = 228) no significant differences were observed in disease-free-survival (p = 0.889) and overall survival (p = 0.426) between patients submitted to further treatment (revision endoscopic surgery or radiotherapy) for positive excision margins and patients who were left untreated. In 20 of 24 (83%) patients with positive margins that were surgically re-excised, no residual carcinoma was detected. Margin status (mainly multifocal and deep positive margins) at first surgery was significantly related to the final organ preservation rate (p < 0.001). Margin status during laser cordectomy in early glottic cancer has a prognostic impact on local control of disease without compromising survival. Patients with multifocal and deep positive borders should be surgically retreated and strictly monitored to increase the organ preservation rates. Careful preparation and mapping of the surgical specimen enhances the accuracy of pathological examination by reducing the risk of overestimate positive margins.

L'angiografia a risonanza magnetica nello studio del circolo cerebrale

Le recenti acquisizioni tecniche hanno rapidamente reso l'angiografia RM una delle più importanti indagini vascolari non invasive. Scopo della nostra ricerca è verificare l'applicabilità clinica dell'angiografia RM e valutare la sua accuratezza diagnostica nei confronti dell'angiografia per via arteriosa (angiografia invasiva) nello studio degli aneurismi del circolo cerebrale. Sono stati esaminati con «Angiografia Tridimensionale a Risonanza Magnetica», basata sul fenomeno del «tempo di volo», 23 pazienti, con un numero complessivo di 25 aneurismi, di cui 4 con dimensioni superiori ad 1,5 cm (macroaneurismi). In tutti i casi sono state utilizzate sequenze ad «Eco di Gradiente» 3D con compensazione per il flusso, mentre nei 4 casi di macroaneurisma sono state impiegate anche sequenze ad «Eco di Gradiente» 2D «single slice». In tutti i pazienti l'angiografia RM è stata associata ad una valutazione con sequenze Spin-Echo del parenchima cerebrale allo scopo di documentare l'eventuale presenza di aree di sofferenza parenchimale. L'angiografia invasiva per via arteriosa era disponibile per il confronto in tutti i casi. 18 pazienti sono stati sottoposti ad intervento chirurgico di «legatura» dell'aneurisma. Nei confonti dell'angiografia invasiva la sensibilità dell'angiografia RM è risultata complessivamente dell' 88% e la specificità del 90%, con un'accuratezza diagnostica dell'89%. Lo studio dimostra come l'angiografia RM, basata sul fenomeno del «tempo di volo», sia in grado di identificare aneurismi di dimensioni fino a 3mm e possa essere utilmente impiegata nella valutazione clinica dell'encefalo come fonte di informazioni supplementari sul circolo cerebrale.

Quantum information processing with hybrid spin-photon qubit encoding

We introduce a scheme to perform quantum information processing that is based on a hybrid spin-photon qubit encoding. The proposed qubits consist of spin ensembles coherently coupled to microwave photons in coplanar waveguide resonators. The quantum gates are performed solely by shifting the resonance frequencies of the resonators on a nanosecond time scale. An additional cavity containing a Cooper-pair box is exploited as an auxiliary degree of freedom to implement two-qubit gates. The generality of the scheme allows its potential implementation with a wide class of spin systems.

Association of metabolic syndrome with kidney function and histology in living kidney donors

The selection of living kidney donors is based on a formal evaluation of the state of health. However, this spectrum of health includes subtle metabolic derangements that can cluster as metabolic syndrome. We studied the association of metabolic syndrome with kidney function and histology in 410 donors from 2005 to 2012, of whom 178 donors were systematically followed after donation since 2009. Metabolic syndrome was defined as per the NCEP ATPIII criteria, but using a BMI > 25 kg/m(2) instead of waist circumference. Following donation, donors received counseling on lifestyle modification. Metabolic syndrome was present in 50 (12.2%) donors. Donors with metabolic syndrome were more likely to have chronic histological changes on implant biopsies than donors with no metabolic syndrome (29.0% vs. 9.3%, p < 0.001). This finding was associated with impaired kidney function recovery following donation. At last follow-up, reversal of metabolic syndrome was observed in 57.1% of donors with predonation metabolic syndrome, while only 10.8% of donors developed de novo metabolic syndrome (p < 0.001). In conclusion, metabolic syndrome in donors is associated with chronic histological changes, and nephrectomy in these donors was associated with subsequent protracted recovery of kidney function. Importantly, weight loss led to improvement of most abnormalities that define metabolic syndrome.

Many-body models for molecular nanomagnets

We present a flexible and effective ab initio scheme to build many-body models for molecular nanomagnets, and to calculate magnetic exchange couplings and zero-field splittings. It is based on using localized Foster-Boys orbitals as a one-electron basis. We apply this scheme to three paradigmatic systems, the antiferromagnetic rings Cr8 and Cr7Ni, and the single-molecule magnet Fe4. In all cases we identify the essential magnetic interactions and find excellent agreement with experiments.

Influence of Processing Conditions on Productivity, Thermal and Rheological Properties of Reprocessed Low Density Polyethylene

The market for recycled thermoplastic polymers is undergoing a sharp increase, although recyclate polymers are regarded as materials with inferior properties when compared to the virgin material. This study investigates the behavior of non-contaminated scraps of low density polyethylene (LDPE) from the plastic packaging industry after single processing stage, in terms of the productivity and the thermal and rheological properties. The LDPE used was reprocessed on a single-screw extruder (Miotto) of 90 mm screw diameter and L/D = 25. Three screw speeds (80, 90 and 100 min−1) were investigated at three processing temperatures (200, 250 and 300°C). The reprocessed materials were characterized by thermogravimetric analysis TGA, parallel plates rheometry and productivity. The results obtained by TGA showed a typical range of polyolefin degradation (350 to 450°C). The viscoelastic properties did not show significant changes in relation to the rheological behavior. Increasing the temperature and screw speed promoted a productivity gain of approximately 30%. This suggests that under the conditions studied it is possible to reprocess this material with good productivity ensuring its thermal, mechanical and rheological properties.

DAOA Variants on Diagnosis and Response to Treatment in Patients with Major Depressive Disorder and Bipolar Disorder

OBJECTIVE: This study investigated whether selected D-amino acid oxidase activator ( DAOA) gene single nucleotide polymorphisms (SNPs; rs3916966, rs3916967, rs2391191, rs3916968, rs7139958, rs9558571, rs778293) are associated with major depressive disorder (MDD) and bipolar disorder (BD), and whether they can predict clinical outcomes in Korean in-patients treated with antidepressants and mood stabilizers, respectively. METHODS: In total, 145 patients with MDD, 132 patients with BD and 170 psychiatrically healthy controls were genotyped for the DAOA SNPs. Baseline and final clinical assessments included the Montgomery—Asberg Depression Rating Scale and Young Mania Rating Scale for patients with MDD and BD, respectively. RESULTS: There was no association between DAOA SNP genotypes or alleles with diagnosis, clinical improvement, response rates or remission rates for MDD and BD. Haplotype analyses found no association with MDD or BD diagnosis or clinical outcomes. CONCLUSIONS: The findings suggest that the DAOA SNPs investigated may not affect MDD or BD phenotype, clinical symptoms or other clinical factors, and are unlikely to be involved in MDD or BD development and treatment outcomes. Given the study's limitations, further investigation should be carried out.

Virologic and immunologic monitoring of cytomegalovirus to guide preemptive therapy in solid-organ transplantation

Control of human cytomegalovirus (HCMV) infection during the posttransplant period was investigated in 134 solid-organ transplant recipients by monitoring in parallel virologic and immunologic parameters for at least 1 year of follow-up. Virologic monitoring was achieved by determining HCMV DNAemia with real-time PCR, using the threshold of 300 000 DNA copies/mL blood as a cutoff for starting preemptive therapy. Immunologic monitoring included measurement of HCMV-specific CD4+ and CD8+ T cells by cytokine flow cytometry, using HCMV-infected dendritic cells as a stimulus. HCMV infection was diagnosed in 110 (82%) and required treatment in 49 (36%) patients. At 12 months after transplantation 'protective' immunity (≥0.4 CD4+ and CD8+ HCMV-specific T cells/μL blood) was achieved in 115/129 (89%) patients. During the entire study period, 122 patients reconstituting HCMV-specific CD4+ and CD8+ T-cell immunity at 60 days posttransplant onward were able to control HCMV infection, except for one patient who developed HCMV disease because of a rejection episode. Patients reconstituting HCMV-specific CD8+ only did not control HCMV infection. In conclusion, the presence of both HCMV-specific CD4+ and CD8+ T cells ≥ 0.4/μL blood appears to be protective against HCMV disease. This result does not apply to patients undergoing antirejection treatment, or reconstituting HCMV-specific CD8+ T cells only.

[Diagnosis of congenital endocrinological disease in newborns with prolonged jaundice and hypoglycaemia]

INTRODUCTION

The association of prolonged neonatal jaundice and hypoglycaemia may be secondary to an endocrinological disease. Pituitary insufficiency and primary adrenal insufficiency are the most likely endocrine diseases that need to be ruled out.

MATERIAL AND METHODS

We retrospectively analysed the clinical and laboratory characteristics of thirteen patients referred to the Hospital de Niños Ricardo Gutiérrez between years 2003 and 2008 due to prolonged neonatal jaundice and hypoglycaemia secondary to pituitary insufficiency in twelve patients, and in one secondary to primary adrenal insufficiency.

RESULTS

All patients had a history of neonatal hypoglycaemia. Ten patients had conjugated hyperbilirubinaemia and six also had elevated transaminases. Combined pituitary hormone deficiency was observed in the twelve hypopituitarism patients. Hormonal replacement normalised liver function and resolved the prolonged jaundice in all the patients. None of them underwent liver biopsy. Hypoglycaemia also remitted after hormonal therapy.

CONCLUSIONS

Prolonged or cholestatic jaundice associated with neonatal hypoglycaemia is highly likely to be due to pituitary hormone deficiency or primary adrenal insufficiency. Early diagnosis and treatment of these children reverts the prolonged jaundice and prevents morbidity and mortality due to recurrent hypoglycaemia and hormone deficiencies.

Early onset of primary hypogonadism revealed by serum anti-Müllerian hormone determination during infancy and childhood in trisomy 21

Male patients with an extra sex chromosome or autosome are expected to present primary hypogonadism at puberty owing to meiotic germ-cell failure. Scarce information is available on trisomy 21, a frequent autosomal aneuploidy. Our objective was to assess whether trisomy 21 presents with pubertal-onset, germ-cell specific, primary hypogonadism in males, or whether the hypogonadism is established earlier and affects other testicular cell populations. We assessed the functional status of the pituitary-testicular axis, especially Sertoli cell function, in 117 boys with trisomy 21 (ages: 2months-20year). To compare with an adequate control population, we established reference levels for serum anti-Müllerian hormone (AMH) in 421 normal males, from birth to adulthood, using a recently developed ultrasensitive assay. In trisomy 21, AMH was lower than normal, indicating Sertoli cell dysfunction, from early infancy, independently of the existence of cryptorchidism. The overall prevalence rate of AMH below the 3rd percentile was 64.3% in infants with trisomy 21. Follicle-stimulating hormone was elevated in patients <6months and after pubertal onset. Testosterone was within the normal range, but luteinizing hormone was elevated in most patients <6months and after pubertal onset, indicating a mild Leydig cell dysfunction. We conclude that in trisomy 21, primary hypogonadism involves a combined dysfunction of Sertoli and Leydig cells, which can be observed independently of cryptorchidism soon after birth, thus prompting the search for new hypotheses to explain the pathophysiology of gonadal dysfunction in autosomal trisomy.

A systematic review of neurobiological and clinical features of mindfulness meditations

BACKGROUND

Mindfulness meditation (MM) practices constitute an important group of meditative practices that have received growing attention. The aim of the present paper was to systematically review current evidence on the neurobiological changes and clinical benefits related to MM practice in psychiatric disorders, in physical illnesses and in healthy subjects.

METHOD

A literature search was undertaken using Medline, ISI Web of Knowledge, the Cochrane collaboration database and references of retrieved articles. Controlled and cross-sectional studies with controls published in English up to November 2008 were included.

RESULTS

Electroencephalographic (EEG) studies have revealed a significant increase in alpha and theta activity during meditation. Neuroimaging studies showed that MM practice activates the prefrontal cortex (PFC) and the anterior cingulate cortex (ACC) and that long-term meditation practice is associated with an enhancement of cerebral areas related to attention. From a clinical viewpoint, Mindfulness-Based Stress Reduction (MBSR) has shown efficacy for many psychiatric and physical conditions and also for healthy subjects, Mindfulness-Based Cognitive Therapy (MBCT) is mainly efficacious in reducing relapses of depression in patients with three or more episodes, Zen meditation significantly reduces blood pressure and Vipassana meditation shows efficacy in reducing alcohol and substance abuse in prisoners. However, given the low-quality designs of current studies it is difficult to establish whether clinical outcomes are due to specific or non-specific effects of MM.

DISCUSSION

Despite encouraging findings, several limitations affect current studies. Suggestions are given for future research based on better designed methodology and for future directions of investigation.

Sexual side effects of pharmacological treatment of psychiatric diseases

Since the introduction of psychiatric medications with relatively good safety profiles, such as selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors, increasing attention has been given to side effects such as sexual dysfunction (SD), which, although unrelated to risks of mortality, could undermine compliance with treatment regimens and impair quality of life. Indeed,there is consistent evidence to suggest that a large number of psychiatric medications adversely affect one or more of the three phases of normal sexual response: desire, arousal, and orgasm.

Association between the estrogen receptor TA polymorphism and Harm avoidance

In the last decade a large number of studies focused on the recognition of gene variants modulating temperamental traits. The gene coding for the estrogen receptor alpha (ESR1) appears to be an interesting candidate and it has been found to be linked to Harm avoidance (HA). The aim of the present study was to investigate whether the ESR1 TA dinucleotide repeat polymorphism is associated with HA temperamental trait in a sample of Caucasian University students. One hundred ninety healthy subjects were genotyped for ESR1 TA dinucleotide repeat polymorphism and were administered the Temperament and Character Inventory (TCI). ESR1 TA repeat lengths were dichotomized into short and long categories. ANOVA was used to examine the influence of ESR1 variants (short/long) on the means of the TCI HA scores. HA was significantly associated with age and gender in our sample, being higher in older and female subjects. In the global sample as well as in men and women separately, individuals carrying the S/S variant showed significantly higher HA scores. Further analysis on the HA subscales revealed that specific differences could exist between men and women. Our results further suggest a possible role of ESR1 variants on HA. Further research is needed to replicate our findings as well as to better explore the neuro-biological mechanisms of the modulation of ESR1 on HA.

Use of a D-optimal mixture design to estimate the effects of diverse chloride salts on the growth parameters of Lactobacillus pentosus

The effects of NaCl, KCl, CaCl(2), and MgCl(2) and their mixtures on the ionic strength (IS) of the medium and the growth parameters of Lactobacillus pentosus were studied by means of a D-optimal mixture experimental design with constrains (total salt concentration<or=9.0%, wt/vol) and the generalized z-value. The IS was linearly related to the concentrations of the diverse salts and its increase, for similar concentrations of salts, followed the order MgCl(2)>CaCl(2)>NaCl>KCl. Within the experimental region, the lag phase duration (lambda) was mainly affected by NaCl and CaCl(2) and the interaction KCl with MgCl(2). The maximum specific growth rate (mu(max)) decreased as NaCl (the highest effect), CaCl(2), and MgCl(2) increased (regardless of the presence or not of previous NaCl); low KCl concentrations had a stimulating effect on mu(max), but its overall effect showed a similar trend to the other salts. The maximum population reached (N(max)) was the least affected parameter and decreased as NaCl and CaCl(2) concentrations increased regardless of the presence of the other salts. The equations that expressed the growth parameters as a function of the diverse chloride salts, within the limits assayed, were developed and the corresponding z- and harmonic Z-values were estimated.

Treatment Emergent Sexual Dysfunction Related to Antidepressants: A Meta-analysis

Objective:

Sexual dysfunction is an important under-estimated side effect of antidepressant drugs. Patients, in fact, if not directly questioned, tend to scarcely report them. Thus, the aim of the present meta-analysis is to quantify sexual dysfunction caused by antidepressants on the basis of studies where sexual functioning was purposely investigated through direct inquiry and specific questionnaires.

Methods:

A literature search was conducted using Medline, Isi web of Knowledge and references of selected articles. Selected studies performed on patients without previous sexual dysfunction were entered in the Cochrane Collaboration Review Manager Software (RevMan version 4.2). Our primary outcome measure was the rate of total treatment emergent sexual dysfunction. Our secondary outcome measures were the rates of treatment emergent desire, arousal and orgasm dysfunction.

Results:

Our analyses indicated significantly higher rates of treatment emergent sexual dysfunction as well as specific phases dysfunction compared to placebo for the following drugs: citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, duloxetine, venlafaxine, clomipramine, imipramine and phenelzine, whereas no significant difference with placebo was found for the following antidepressants: amineptine, bupropion, moclobemide, mirtazapine and nefazodone. Nonetheless sufficient evidences (>100 subjects) are available only for bupropion, citalopram, fluoxetine, paroxetine, sertraline and venlafaxine.

Discussion:

Present evidence on treatment emergent sexual dysfunction caused by antidepressant is sufficiently studied only for few drugs. Furthermore some statistical limiting assumptions, as the inclusion of open label or small studies and the presence of an evident publication bias, could reduce the significativity of our findings. Thus, treatment emergent sexual dysfunction should be more deeply investigated.

Control of human cytomegalovirus infection in patients infected with human immunodeficiency virus by high levels of specific CD8+ T-cells

A new technique was used to simultaneously determine human cytomegalovirus (HCMV)-specific CD4(+) and CD8(+) T-cells in highly active anti-retroviral therapy (HAART)-naive and HAART-treated patients infected with human immunodeficiency virus (HIV). HIV-infected patients with HCMV infection, but without HCMV disease, showed low numbers of HCMV-specific CD4(+) cells and high numbers of CD8(+) T-cells, both before and during HAART. HIV-infected patients with HCMV disease had no HCMV-specific CD4(+) T-cells and extremely low levels of CD8(+) T-cells. Resolution of disease during HAART was associated with rescue of specific CD4(+) T-cells and a large increase in the specific CD8(+) T-cell count. Thus, HAART does not completely restore the normal immune function. In HIV-infected patients, sustained control of HCMV infection requires high frequencies of specific CD8(+) T-cells.

Distribution of killer cell immunoglobulin-like receptors genes in the Italian Caucasian population

Background

Killer cell immunoglobulin-like receptors (KIRs) are a family of inhibitory and activatory receptors that are expressed by most natural killer (NK) cells. The KIR gene family is polymorphic: genomic diversity is achieved through differences in gene content and allelic polymorphism. The number of KIR loci has been reported to vary among individuals, resulting in different KIR haplotypes. In this study we report the genotypic structure of KIRs in 217 unrelated healthy Italian individuals from 22 immunogenetics laboratories, located in the northern, central and southern regions of Italy.

Methods

Two hundred and seventeen DNA samples were studied by a low resolution PCR-SSP kit designed to identify all KIR genes.

Results

All 17 KIR genes were observed in the population with different frequencies than other Caucasian and non-Caucasian populations; framework genes KIR3DL3, KIR3DP1, KIR2DL4 and KIR3DL2 were present in all individuals. Sixty-five different profiles were found in this Italian population study. Haplotype A remains the most prevalent and genotype 1, with a frequency of 28.5%, is the most commonly observed in the Italian population.

Conclusion

The Italian Caucasian population shows polymorphism of the KIR gene family like other Caucasian and non-Caucasian populations. Although 64 genotypes have been observed, genotype 1 remains the most frequent as already observed in other populations. Such knowledge of the KIR gene distribution in populations is very useful in the study of associations with diseases and in selection of donors for haploidentical bone marrow transplantation.

[Hapten selection for patch tests in the diagnosis of allergic contact dermatitis: epidemiologic data]

Aim of the study was to verify the reliability in clinical practice of patch testing with "standard" series and additional series of haptens for the diagnosis of occupational and non-occupational allergic contact dermatitis, evaluating positive reactions and relating those reactions to professional categories. A total of 392 out of 937 patients (41.8%) showed at least one positive reaction to "standard" series testing; the hapten most frequently noted as the cause of positive reaction was nickel sulphate. Professional categories that showed positive reactions to "standard" series most frequently were clerks, hairdressers and hospital auxiliary workers. Among 897 patients tested with nonstandard allergens, only 124 (13.8%) elicited at least one positive reaction, ammonium persulphate being the most frequently positive hapten. A dominant percentage of positive results was seen in hairdressers and cleaning personnel. No positive reactions were observed in a large number of haptens, tested more than 200 times. Haptens of "standard series" elicited a higher number of positive reaction than the additional series, even though there was a high specificity of few additional series haptens in some professional categories. Data suggest some caution in systematically testing additional series, despite a higher accuracy and diagnostic efficacy in some job categories.

Retreatment with interferon plus ribavirin of chronic hepatitis C non-responders to interferon monotherapy: a meta-analysis of individual patient data

BACKGROUND AND AIMS

Retreatment with a combination of alpha interferon (IFN) plus ribavirin of patients with chronic hepatitis C who did not respond to IFN monotherapy has not been assessed in large controlled studies.

METHODS

To assess the effectiveness and tolerability of IFN/ribavirin retreatment of non-responders to IFN and to identify predictors of complete (biochemical and virological) sustained response, we performed a meta-analysis of individual data on 581 patients from 10 centres. Retreatment with various IFN schedules (mean total dose 544 mega units) and a fixed ribavirin dose (1000-1200 mg/daily depending on body weight) was given for 24-60 (mean 39.5) weeks.

RESULTS

Biochemical end of treatment and sustained responses were observed in 271/581 (46.6%; 95% confidence interval (CI) 42.6-50.7%) and in 109/581 (18.7%; 95% CI 15.6-22.0%) cases, respectively. Two hundred and six of 532 patients (38.7%; 95% CI 34.6-42.9%) had an end of treatment complete response to retreatment while a complete sustained response occurred in 88 of 559 (15.7%; 95% CI 12.8-18.8%). Fifty four of 581 patients (9.2%; 95% CI 7.0-11.7%) stopped retreatment due to adverse effects. By logistic regression, complete sustained response was predicted independently by age <45 years (p=0.04), by normal pretreatment gamma-glutamyltransferase levels (p=0.01), and by a second course total IFN dose of at least 432 mega units (p=0.008).

CONCLUSIONS

The overall low probability of effectiveness argues against indiscriminate retreatment of all IFN monotherapy non-responders with IFN/ribavirin. Patients less than 45 years old with normal gamma-glutamyltransferase levels who were retreated with high dose long course combination therapy had a complete sustained response rate of 30%.

Thyroid dysfunction and high thyroid stimulating hormone levels in children with Down's syndrome

In order to delineate the spectrum of thyroid abnormalities in children with Down's syndrome (DS), first visit height data (SDS) and serum TSH, T4 and antiperoxidase antibodies concentrations were retrospectively evaluated in 137 children (71 girls) with DS (0.04-16 years).

RESULTS

Congenital hypothyroidism was detected in 2.9% of patients. Thyroid disease occurred in 9%: four hyperthyroidism and eight hypothyroidism. Overt thyroid disease was always related to thyroid autoimmunity. The remaining 121 patients had normal T4 levels but increased mean TSH compared with controls (4.7 +/- 2.8 vs 2.3 +/- 1.3 mU/l). According to TSH levels, they were divided into two groups: G1 (n = 68) with normal TSH (<5 mU/l), and G2 (n = 53) with high TSH (> 5 mU/l). T4 levels were significantly lower in G2 (p < 0.01 vs G1 and controls). Height SDS was not different.

CONCLUSIONS

Thyroid disorders are frequent in children with DS. Subtle thyroid abnormalities found in patients with DS with no evidence of clinical dysfunction need further investigation to demonstrate whether there is a need for therapeutic intervention.

Neonatal screening program for congenital adrenal hyperplasia: adjustments to the recall protocol

OBJECTIVE

To evaluate the influence of gestational age (GA) and birth weight (BW) on 17 alpha-OH-progesterone (17-OHP) levels with respect to their impact on the recall rate of neonatal screening programs for congenital adrenal hyperplasia (CAH).

PATIENTS AND METHODS

In June 1997 we began a pilot screening program for CAH measuring 17-OHP using a fluoroimmunoassay method (DELFIA) on dried blood spots. Until September 1999, 24,153 babies were screened. Among them, we analyzed the levels of 17-OHP in 1,313 samples from healthy preterm babies (23-36 weeks) and 1,500 term babies (>37 weeks), grouped according to GA and BW. All preterm babies underwent another sampling in their 2nd week of life.

RESULTS

5 CAHs were detected. The 30-nmol/l cutoff limit for 17-OHP in blood corresponded to the calculated 99th percentile in term newborns, while in preterm babies higher levels were found. GA and BW correlated inversely with 17-OHP levels.

CONCLUSION

GA and BW were useful tools to adjust cutoff levels, obtaining a significant reduction in follow-up testing and psychological stress for families. The high false-positive recall rate in preterm babies can be substantially lowered with adjusted GA and/or BW criteria.

Higher levels of HIV DNA in memory and naive CD4(+) T cell subsets of viremic compared to non-viremic patients after 18 and 24 months of HAART

The degree of infection of memory and naive CD4(+) T cells in patients treated with HAART and with durable undetectable or detectable viral load in plasma was evaluated. The following two groups of patients were analyzed cross-sectionally: (i) patients with undetectable HIV RNA plasma levels during follow-up (responders); (ii) patients with no reduction or with rebound in HIV RNA levels during treatment (non-responders). Patients were examined following 6, 12, 18 and 24 months of HAART, respectively, by quantifying: (i) plasma HIV RNA load; (ii) CD4(+) T cells; (iii) memory and naive CD4(+) T cells; (iv) HIV DNA levels in memory and naive CD4(+) T cells. HIV RNA plasma levels were significantly higher in non-responders vs responders at each time point (P<0.02), while CD4(+) T cell counts as well as memory and naive CD4(+) T cell levels were comparable in both viremic and non-viremic patients. However, higher HIV DNA values were observed in both memory and naive CD4(+) T cells of non-responders vs responders after 18 and 24 months of HAART (P<0.02), suggesting an increased amount of HIV-infected naive CD4(+) T cells and a sustained high degree of infection of memory CD4(+) T cells. Immunological reconstitution following HAART might potentially be hampered in viremic patients despite the absolute increase in CD4(+) T cell counts.

Recombinant aequorin and green fluorescent protein as valuable tools in the study of cell signalling

Luminous proteins include primary light producers, such as aequorin, and secondary photoproteins that in some organisms red-shift light emission for better penetration in space. When expressed in heterologous systems, both types of proteins may act as versatile reporters capable of monitoring phenomena as diverse as calcium homoeostasis, protein sorting, gene expression, and so on. The Ca(2+)-sensitive photoprotein aequorin was targeted to defined intracellular locations (organelles, such as mitochondria, endoplasmic reticulum, sarcoplasmic reticulum, Golgi apparatus and nucleus, and cytoplasmic regions, such as the bulk cytosol and the subplasmalemmal rim), and was used to analyse Ca(2+) homoeostasis at the subcellular level. We will discuss this application, reviewing its advantages and disadvantages and the experimental procedure. The applications of green fluorescent protein (GFP) are even broader. Indeed, the ability to molecularly engineer and recombinantly express a strongly fluorescent probe has provided a powerful tool for investigating a wide variety of biological events in live cells (e.g. tracking of endogenous proteins, labelling of intracellular structures, analysing promoter activity etc.). More recently, the demonstration that, using appropriate mutants and/or fusion proteins, GFP fluorescence can become sensitive to physiological parameters or activities (ion concentration, protease activity, etc.) has further expanded its applications and made GFP the favourite probe of cell biologists. We will here present two applications in the field of cell signalling, i.e. the use of GFP chimaeras for studying the recruitment of protein kinase C isoforms and the activity of intracellular proteases.

Usefulness of thyroxine and free thyroxine filter paper measurements in neonatal screening for congenital hypothyroidism of preterm babies

INTRODUCTION

Low thyroxine (T4) with normal thyroid stimulating hormone (TSH) is a well known condition in preterm (PT) infants. The establishment of T4 and freeT4 (FT4) values in filter paper dried blood spots in PT could provide useful information in the neonatal period.

OBJECTIVE

To study T4 and FT4 levels in dried blood filter paper samples of PT and full term (FT) babies.

METHODS

We measured T4 by fluoroimmunoassay (FIA) DELFIA and TSH by IFMA DELFIA (Wallac Inc Turku, Finland) in 193 PT (26 to 37 weeks of gestational age (GA)) in samples from the first and second week of life and in 153 FT babies in the first week of life. In 131 PT and 31 FT we determined FT4 in filter paper blood spots using FIA (Alonso Fernandez J). Infants were grouped according to GA.

RESULTS

There was a significant difference in T4 between PT and FT (p < 0.001). The lowest T4 levels were at 26 to 29 weeks GA. T4 values were lower in the second week. FT4 in PT up to 35 weeks GA, during the first week, was significantly different with FT infants (G1 to G3 p < 0.01, G4 p < 0.05). FT4 values in the first and second weeks of life did not vary.

CONCLUSIONS

T4 values were significantly lower in PT than in FT neonates, increasing with GA. PT infants had low T4 with normal FT4 values. This could suggest a decreased thyroxine binding globulin (TBG) or decreased protein binding and/or an adaptative mechanism that would not require therapeutical intervention.

Nocturnal TSH surge and TRH test response in the evaluation of thyroid axis in hypothalamic pituitary disorders in childhood

We studied, by means of TSH nocturnal secretion and TRH test, 42 children (4.2-19.9 years) with hypothalamic pituitary disorders and 24 healthy euthyroid children (5.7-15.4 years) as control group. Patients were divided according to their serum values of FT4 in group 1 (n = 27) with FT4 >/=10.3 pmol/l and group 2 (n = 15) with FT4 <10.3 pmol/l. TSH was measured by immunoradiometric assay. TSH nadir, TSH peak and TSH surge were calculated. Both groups differed significantly from control group in TSH surge values: group 1 (p < 0. 05), group 2 (p < 0.01). TRH test was abnormal in 11/27 patients of group 1 and 10/15 patients of group 2. In group 1, 7 patients had normal tests, 2 had abnormalities in both tests, 9 had only TSH nocturnal surge altered and 9 showed only TRH alterations. All patients of group 2 presented thyroid axis abnormalities. In conclusion, in patients with hypothalamic pituitary disorders with low FT4, no further investigation is required to demonstrate thyroid axis alterations, however in patients with normal FT4, nocturnal TSH secretion and TRH test may be required to evidence thyroid abnormalities.

Congenital absence of portal vein with nodular regenerative hyperplasia of the liver

Congenital absence of the portal vein is a very rare anomaly. The intestinal and splenic venous drainage bypasses the liver and drain into the inferior vena cava (IVC). Two cases of such anomaly are described. Both cases were investigated by US coupled with echo-colour Doppler examination, CT and MR imaging, followed by digital subtraction angiography (DSA) and liver biopsy. In the first case the splenic and superior mesenteric vein formed a venous trunk which emptied directly into the IVC; in the second case, the splanchnic blood flowed into a dilated hepatofugal inferior mesenteric vein which connected to the left internal iliac vein. In both cases nodular regenerative hyperplasia of the liver was present, presumably due to an abnormal hepatic cell response to the absent portal flow. The particular contribution of MR imaging to the diagnosis of both vascular abnormalities and liver parenchyma derangement and its advantages over the other diagnostic techniques is emphasized. The clinical and radiological features of 17 previously reported cases are reviewed.

Focal liver lesions: evaluation of the efficacy of gadobenate dimeglumine in MR imaging--a multicenter phase III clinical study

PURPOSE

To evaluate gadobenate dimeglumine (Gd-BOPTA) for dynamic and delayed magnetic resonance (MR) imaging of focal liver lesions.

MATERIALS AND METHODS

In 126 of 214 patients, MR imaging was performed before Gd-BOPTA administration, immediately after bolus administration of a 0.05- mmol/kg dose of Gd-BOPTA, and 60-120 minutes after an additional intravenously infused 0.05-mmol/kg dose. In 88 patients, imaging was performed before and 60-120 minutes after a single, intravenously infused 0.1-mmol/kg dose. T1- and T2-weighted spin-echo and T1-weighted gradient-echo images were acquired. On-site and blinded off-site reviewers prospectively evaluated all images. Intraoperative ultrasonography, computed tomography (CT) during arterial portography, and/or CT with iodized oil served as the reference methods in 110 patients.

RESULTS

Significantly more lesions were detected on combined pre- and postcontrast images compared with on precontrast images alone (P <. 01). All reviewers reported a decreased mean size of the smallest detected lesion and improved lesion conspicuity on postcontrast images. All on-site reviewers and two off-site reviewers reported increased overall diagnostic confidence (P <.01). Additional lesion characterization information was provided on up to 109 (59%) of 184 delayed images and for up to 50 (42%) of 118 patients in whom dynamic images were assessed. Gd-BOPTA would have helped change the diagnosis in 99 (47%) of 209 cases and affected patient treatment in 408 (23%) of 209 cases.

CONCLUSION

Gd-BOPTA increases liver lesion conspicuity and detectability and aids in the characterization of lesions.