Correction to: Characteristics of taste dysfunction in COVID‑19 subjects coming from two different countries

Journal of NeuroVirology - A correction to this paper has been published: https://doi.org/10.1007/s13365-021-00976-y     

Paediatric focal nodular hyperplasia: A case study of typical contrast-enhanced ultrasound findings with quantitative analysis and correlated with magnetic resonance imaging

IntroductionFocal nodular hyperplasia, a benign liver tumour, is the second most common focal benign liver lesion, after a cavernous haemangioma. Contrast-enhanced ultrasound is used increasingly for the diagnostic work up and follow-up of focal liver lesions in adults, but is particularly valuable in the paediatric population, with the ability to reduce radiation and the nephrotoxic contrast agents used in computed tomography or magnetic resonance imaging. Confident recognition of focal nodular hyperplasia is important; it is benign, usually asymptomatic, of no clinical significance, of no clinical consequence or malignant potential. We present a case of focal nodular hyperplasia of the liver with its characteristic findings on conventional ultrasound, contrast-enhanced ultrasound with quantitative analysis and correlated with magnetic resonance imaging.Case presentation: A 15-year-old female with right upper quadrant abdominal pain was referred for liver ultrasound. A focal liver lesion was detected on B-mode ultrasound examination, and colour Doppler demonstrated no specific features. Contrast-enhanced ultrasound examination demonstrated early arterial enhancement, with a characteristic spoke-wheel pattern, centrifugal uniform filling of the lesion on the late arterial phase and sustained enhancement on the portal venous phase. Quantitative contrast-enhanced ultrasound has been performed, showing a typical curve of enhancement, as well as characteristic parametric images, supporting the interpretation of contrast-enhanced ultrasound and assisting the diagnosis. Magnetic resonance imaging demonstrated a central T2 hyperintense scar and similar enhancement characteristics as contrast-enhanced ultrasound on T1 gadolinium-enhanced sequences.ConclusionContrast-enhanced ultrasound is a useful technique for the differentiation of benign from malignant liver lesions and has the potential to establish the diagnosis of focal nodular hyperplasia, based on the enhancement pattern, which is similar to that observed on magnetic resonance imaging but can be better appreciated with superior temporal, contrast and spatial resolution of contrast-enhanced ultrasound.     

Common carotid intima-media thickness in growth hormone (GH)-deficient adolescents: a prospective study after GH withdrawal and restarting GH replacement

We prospectively investigated the risk of early atherosclerosis, by classical cardiovascular risk factors and intima-media thickness (IMT) at the common carotid arteries, in 23 adolescents diagnosed as GH deficient (GHD) during childhood and in 23 healthy sex-, age-, and BMI-matched controls. Measurements were performed in all subjects before stopping GH replacement. Because the diagnosis of GHD had been confirmed in 15 of the 23 adolescents, the protocol changed according to the diagnosis as follows: measurements were repeated after 6 months of GH withdrawal and 6 months of GH reinstitution in the 15 with GHD, and after 6 and 12 months of GH withdrawal, measurements were also taken in the eight non-GHD subjects. Serum IGF-I levels were in the normal range for age in all patients before GH withdrawal. When compared with controls, before GH withdrawal, GHD adolescents had reduced high-density lipoprotein cholesterol levels and increased total/high-density lipoprotein cholesterol ratio, fibrinogen, low-density lipoprotein cholesterol, and glucose levels; non-GHD adolescents had increased glucose, insulin, and homeostasis model assessment score. IMT at the common carotid arteries was similar in GHD and controls (0.52 +/- 0.03 vs. 0.55 +/- 0.06 mm; P = 0.23) and was higher in non-GHD than in controls (0.62 +/- 0.03 vs. 0.54 +/- 0.06 mm; P = 0.01). In GHD adolescents, 6 months of GH treatment withdrawal and 6 months of GH treatment reinstitution modified IGF-I levels, lipid profile, and insulin resistance but not IMT or systolic and diastolic peak velocities at the common carotid arteries. In non-GHD subjects, 12 months of GH treatment withdrawal significantly decreased IGF-I levels, IMT (to 0.54 +/- 0.06 mm; P < 0.001 vs. baseline), systolic and diastolic peak velocities, and improved insulin resistance. In conclusion, the discontinuation of GH in confirmed GHD adolescents is not followed by significant alterations of the common carotid arteries, despite the profound negative alterations of the lipid profile. In adolescents who were not confirmed to have GHD, IMT was increased while on GH therapy and normalized when they were taken off of GH.     

Metabolic and cardiopulmonary effects of detraining after a structured exercise training programme in young PCOS women

Objective The aim of the present study was to determine if the favourable cardiopulmonary and metabolic benefits induced by exercise training (ET) programme are maintained after its cessation. Patients Thirty‐two young overweight polycystic ovary syndrome (PCOS) women matched for age and body mass index (BMI) with other 32 PCOS patients was enrolled. The first group [PCOS‐T (trained)] underwent 24‐week ET programme, whereas the second [PCOS‐DT (detrained)] underwent 12‐week ET programme followed by 12‐week detraining period. Methods At baseline, after 12‐ and 24‐week follow‐up, all PCOS women were studied for their hormonal (ovarian and adrenal androgens), metabolic (glucose and insulin) and lipid profile, and underwent cardiopulmonary exercise test. Results After the initial 12‐week ET programme, both PCOS‐T and PCOS‐DT groups, without differences between groups, showed a similar significant (P < 0·05) improvement in BMI, fasting insulin, areas under curve insulin (AUC_INS), glucose and insulin AUC (AUC_GLU/INS), high‐density lipoprotein‐cholesterol (HDL‐C), low‐density lipoprotein‐cholesterol (LDL‐C) and maximal oxygen consumption at cardiopulmonary exercise test (VO_2max). At 24‐week follow‐up, PCOS‐T group showed a significant (P < 0·05) improvement in BMI, fasting insulin, AUC_INS, AUC_GLU/INS, LDL‐C, HDL‐C and VO_2max, in comparison to baseline and 12‐week follow‐up. At same follow‐up visit, the all parameters resulted significantly (P < 0·05) worsened in PCOS‐DT group in comparison to 12‐week follow‐up and PCOS‐T group. In PCOS‐DT group, no parameter assessed at 24‐week follow‐up was significantly different in comparison with baseline. Conclusion In young PCOS women, 12‐week detraining resulted in a complete loss of the favourable adaptations obtained after ET.     

New perspectives on the long-term outcome of segmental colectomy for Crohn’s colitis: an observational study on 200 patients

Background and aims

Surgical management of Crohn’s colitis represents one of the most complex situations in colorectal surgery. Segmental colectomy (SC) and total abdominal colectomy with ileorectal anastomosis (TAC-IRA) are the most common procedures, but there are few available data on their long-term outcome. The aim of the present study was to analyze the long-term outcome of patients who underwent segmental colectomy for Crohn’s colitis, with regard to the risk for total abdominal colectomy.

Methods

In this observational, monocentric, retrospective analysis, we analyzed patients who received a segmental colectomy for Crohn’s colitis at our institution. The database was updated by asking patients to complete a questionnaire by telephone or at the outpatient clinic. Only patients followed up at our Hospital were included. Patients were followed up by a specialized multidisciplinary team (IBD Unit). The primary endpoint was the interval between segmental colectomy and, when performed, total abdominal colectomy.

Results

Between 1973 and 2014, 200 patients underwent segmental colectomy for Crohn’s colitis. The median follow-up was 13.5 years (interquartile range [IQR] 7.8–21.5). Overall, 62 patients (31%) had a surgical recurrence, of these, 42 (21%) received total abdominal colectomy. At multivariate analysis, the presence of ≥?3 sites (HR =?2.47; 95% CI 1.22–5.00; p?=?0.018) and perianal disease (HR =?3.23; 95% CI 1.29–8.07; p?=?0.006) proved to be risk factors for total abdominal colectomy.

Conclusions

The risk for surgical recurrence after SC for Crohn’s colitis is acceptable. We recommend a bowel-sparing policy for the treatment of Crohn’s colitis in any case in which the extent of the disease at the moment of surgery makes the conservative approach achievable.

     

Neurological examination findings to predict limitations in mobility and falls in older persons without a history of neurological disease

PURPOSE: To estimate the prevalence of neurological signs and their association with limitations in mobility and falls in a sample of older persons without known neurological disease. METHODS: A neurologist examined 818 participants from the InCHIANTI study who were aged > or =65 years and who did not have cognitive impairment, treatment with neuroleptics, and a history of neurological disease. Mobility was assessed as walking speed and self-reported ability to walk at least 1 km without difficulty. Participants were asked to report falls that had occurred in the previous 12 months. RESULTS: Less than 20% (160/818) of participants had no neurological signs. Neurological signs were more prevalent in older participants and those with impaired mobility. When all neurological signs were included in sex-and age-adjusted multivariate models, 10 were mutually independent correlates of poor mobility. After adjusting for age and sex, the number of neurological signs was associated with progressively slower walking speed (P <0.001), a higher probability of reported inability to walk 1 km (P <0.001), and a history of falls (P <0.05). CONCLUSION: Neurological signs are independent correlates of limitations in mobility and falls in older persons who have no clear history of neurological disease.     

Nanocomposites Based on Luminescent Colloidal Nanocrystals and Polymeric Ionic Liquids towards Optoelectronic Applications

Polymeric ionic liquids (PILs) are an interesting class of polyelectrolytes, merging peculiar physical-chemical features of ionic liquids with the flexibility, mechanical stability and processability typical of polymers. The combination of PILs with colloidal semiconducting nanocrystals leads to novel nanocomposite materials with high potential for batteries and solar cells. We report the synthesis and properties of a hybrid nanocomposite made of colloidal luminescent CdSe nanocrystals incorporated in a novel ex situ synthesized imidazolium-based PIL, namely, either a poly(N-vinyl-3-butylimidazolium hexafluorophosphate) or a homologous PIL functionalized with a thiol end-group exhibiting a chemical affinity with the nanocrystal surface. A capping exchange procedure has been implemented for replacing the pristine organic capping molecules of the colloidal CdSe nanocrystals with inorganic chalcogenide ions, aiming to disperse the nano-objects in the PILs, by using a common polar solvent. The as-prepared nanocomposites have been studied by TEM investigation, UV-Vis, steady-state and time resolved photoluminescence spectroscopy for elucidating the effects of the PIL functionalization on the morphological and optical properties of the nanocomposites.     

Regulation of photosystem I light harvesting by zeaxanthin

In oxygenic photosynthetic eukaryotes, the hydroxylated carotenoid zeaxanthin is produced from preexisting violaxanthin upon exposure to excess light conditions. Zeaxanthin binding to components of the photosystem II (PSII) antenna system has been investigated thoroughly and shown to help in the dissipation of excess chlorophyll-excited states and scavenging of oxygen radicals. However, the functional consequences of the accumulation of the light-harvesting complex I (LHCI) proteins in the photosystem I (PSI) antenna have remained unclarified so far. In this work we investigated the effect of zeaxanthin binding on photoprotection of PSI–LHCI by comparing preparations isolated from wild-type Arabidopsis thaliana (i.e., with violaxanthin) and those isolated from the A. thaliana nonphotochemical quenching 2 mutant, in which violaxanthin is replaced by zeaxanthin. Time-resolved fluorescence measurements showed that zeaxanthin binding leads to a previously unrecognized quenching effect on PSI–LHCI fluorescence. The efficiency of energy transfer from the LHCI moiety of the complex to the PSI reaction center was down-regulated, and an enhanced PSI resistance to photoinhibition was observed both in vitro and in vivo. Thus, zeaxanthin was shown to be effective in inducing dissipative states in PSI, similar to its well-known effect on PSII. We propose that, upon acclimation to high light, PSI–LHCI changes its light-harvesting efficiency by a zeaxanthin-dependent quenching of the absorbed excitation energy, whereas in PSII the stoichiometry of LHC antenna proteins per reaction center is reduced directly.In eukaryotic photosynthetic organisms, photosystem I (PSI) and photosystem II (PSII) comprise a core complex hosting cofactors involved in electron transport and an outer antenna system made of light-harvesting complexes (LHCs): Lhcas for PSI and Lhcbs for PSII. The core complexes bind chlorophyll a (Chl a) and β-carotene, whereas the outer antenna system, in addition to Chl a, binds chlorophyll b (Chl b) and xanthophylls. Despite their overall similarity, PSI and PSII differ in the rate at which they trap excitation energy at the reaction center (RC), with PSI being faster than PSII (1–9). They also differ in their structure (10–12). PSI is monomeric and carries its antenna moiety on only one side as a half-moon–shaped structure whose size is not modulated by growth conditions (13, 14). PSII, on the other hand, is found mainly as a dimeric core surrounded by an inner layer of antenna proteins (Lhcb4–6) and an outer layer of heterotrimeric LHCII complexes (Lhcb 1–3) whose stoichiometry varies depending on the growth conditions (7, 12, 13, 15). Acclimation to high irradiance leads to a lower number of trimers per PSII RC accompanied by loss of the monomeric Lhcb6. These slow acclimative responses regulate the excitation pressure on the PSII RC, preventing saturation of the electron transport chain (16) and the oxidative stress in high light (HL), leading to photoinhibition. The response to rapid changes in light level is managed by turning on some photoprotective mechanisms, such as the nonphotochemical quenching (NPQ) of the excess energy absorbed by PSII (16), which is activated by the acidification of the thylakoid lumen and protonation of the trigger protein PsbS or LhcSR. Low luminal pH also activates violaxanthin de-epoxidase (VDE), catalyzing the de-epoxidation of the xanthophyll violaxanthin to zeaxanthin (17, 18), a scavenger of reactive oxygen species (ROS) produced by excess light (9, 13). Zeaxanthin also enhances NPQ, as observed in vivo by a decrease of PSII fluorescence (19). The short-term effects of exposure to HL on PSI have been disregarded thus far. Because of its rapid photochemistry, PSI shows low fluorescence emission, implying a low ¹Chl* concentration and a low probability that chlorophyll triplet states will be formed by intersystem crossing. This characteristic suggests that the formation of oxygen singlet excited states (¹O*₂) is reduced and that NPQ phenomena in photoprotection are less relevant in PSI (20, 21). Nevertheless, several reports have shown that, especially in the cold (22–29), PSI can exhibit photo-inhibition, with its Lhca proteins being the primary target (24, 30). Upon synthesis in HL, zeaxanthin binding could be traced to two different types of binding site. One, designated “V1,” is located in the periphery of LHCII trimers (31–33). The second, designated “L2,” has an inner location in the dimeric Lhca1–4 and the monomeric Lhcb4–6 members of the LHC family (34–37). Experimental determination of the efficiency of the violaxanthin-to-zeaxanthin exchange yielded a maximal score in the Lhca3 and Lhca4 subunits (24, 25). Interestingly, Lhca1/4 and Lhca2/3 are bound to the PSI core as dimers that can be isolated in fractions identified as “LHCI-730” and “LHCI-680,” respectively, both accumulating zeaxanthin to a de-epoxidation index of ∼0.2 (20, 38). Lhca3 and Lhca4 carry low-absorption-energy chlorophyll forms known as “red forms” (39, 40) that are responsible for the red-shifted PSI emission peak at 730–740 nm at 77 K. The molecular basis for red forms is an excitonic interaction of two chromophores: chlorophylls 603 and 609 located a few angstroms from the xanthophyll in site L2, which can be either violaxanthin or zeaxanthin depending on light conditions (41, 42). It is unclear whether the binding of zeaxanthin to the PSI–LHCI complex has specific physiological function(s) or is simply a result of its common origin with Lhcb proteins.The goal of this study was to understand whether zeaxanthin plays a role in PSI–LHCI photoprotection. To investigate the role of zeaxanthin bound to Lhca proteins, we analyzed the changes in antenna size and Chl a fluorescence dynamics in PSI supercomplexes binding either violaxanthin or zeaxanthin. We found a zeaxanthin-dependent regulation of PSI antenna size and an enhanced resistance to excess light upon zeaxanthin binding. These results show that dynamic changes in the efficiency of light use and in photoprotection capacity are not exclusive to PSII, as previously thought; instead, eukaryotic photosynthetic organisms modulate the function of both photosystems in a coordinated manner.     

Ceftolozane/tazobactam for the treatment of serious Pseudomonas aeruginosa infections: a multicentre nationwide clinical experience

This study describes the largest clinical experience using ceftolozane/tazobactam (C/T) for different Pseudomonas aeruginosa infections. A retrospective study was performed at 22 hospitals in Italy (June 2016–March 2018). All adult patients treated with ≥4 days of C/T were enrolled. Successful clinical outcome was defined as complete resolution of clinical signs/symptoms related to P. aeruginosa infection and lack of microbiological evidence of infection. C/T treatment was documented in 101 patients with diverse infections, including nosocomial pneumonia (31.7%), acute bacterial skin and skin-structure infection (20.8%), complicated UTI (13.9%), complicated IAI (12.9%), bone infection (8.9%) and primary bacteraemia (5.9%). Over one-half of P. aeruginosa strains were XDR (50.5%), with 78.2% of isolates resistant to at least one carbapenem. C/T was used as first-line therapy in 39 patients (38.6%). When used as second-line or later, the most common reasons for discontinuation of previous antibiotics were in vitro resistance of P. aeruginosa and clinical failure of previous therapy. Concomitant antibiotics were reported in 35.6% of patients. C/T doses were 1.5 g q8h in 70 patients (69.3%) and 3 g q8h in 31 patients (30.7%); median duration of C/T therapy was 14 days. Overall clinical success was 83.2%. Significant lower success rates were observed in patients with sepsis or receiving continuous renal replacement therapy (CRRT). Mild adverse events were reported in only three patients. C/T demonstrated a favourable safety and tolerability profile regardless of the infection type. Clinicians should be aware of the risk of clinical failure with C/T therapy in septic patients receiving CRRT.