Effects of a ketogenic mediterranean diet on physiological and psychological variables

Ketogenic diets (KDs) are diets in which the net carbohydrate intake, calculated by subtracting fibres from total carbohydrates, is between 20 and 50 g/day (<10% of total energy intake) with a variable proportion of proteins and fats (Noakes, Windt 2017). In these conditions, glycogen stores are depleted (Paoli, Canato et al. 2011), insulin level is low and energy metabolism is mainly dependent from fat oxidation. KDs lead a significant increase in circulating levels of ketone bodies (KBs) β-hydroxybutyrate (βOHB), acetoacetate (AcAc) and acetone (Veldhorst, Westerterp et al. 2010). While AcAc and βOHB are used as energy, acetone is a volatile compound and is eliminated through expiration, giving the “sweet” breath odour typical of ketosis, or via renal excretion (Paoli, Canato et al. 2011). The concentration of KBs in the blood of healthy individuals during the carbohydrate fed state is about 0.1 mmol/L and increases to about 0.3 mmol/L after an overnight fast, but after prolonged fasting up to 20 days KBs can increase to more than 10 mmol/L. A diet is considered “ketogenic” when produces a stable increase in the level of βOHB higher than 0.6 mmol/L (Wiggam, O'Kane et al. 1997) or when the molar ratio of blood glucose to blood ketone body βOHB is less than or equal to 1 (Meidenbauer, Mukherjee et al. 2015). Since KBs AcAc and βOHB are acids, the ketosis state implies a condition of acidosis. Given the fact that the pH of the blood is 7.4 and that the pKa of AcAc is 3.8 and that of βOHB is 4.8, these acids circulate in the blood in a completely dissociated form and are eliminated together with sodium and potassium ions (Siliprandi & Tettamanti 2011). This loss of cations implies a decrease of pH, which is normally balanced from the body apart when potassium and sodium intake are impaired (Phinney 2004) or in pathological overproduction of KBs during untreated diabetes type 1 which leads to diabetic ketoacidosis, characterized by a KBs level higher than 20 mmol/L with a decrease of pH. Biochemistry Hans Krebs was the first who diversified physiologic from pathologic ketosis (Krebs 1966). For skeletal and cardiac muscle, which usually oxidize fats, the use of KBs is a relative advantage, while for the central nervous system, in which the entrance of fatty acids is prevented from the blood-brain-barrier (BBB), the availability of KBs is an important surrogate of glucose, which is the habitual substrate of nervous tissue. During starvation, under a ketogenic diet or in new-born infants, the brain can utilize KBs as primary fuel instead of glucose (Laeger, Metges et al. 2010) in proportion to the degree of ketosis (Hartman, Gasior et al.). βOHB is the most abundant circulating ketone body and its transport across the blood-brain barrier is mediated both by diffusion and by several monocarboxylic acid transporters as MCT1 and MCT2, the former being upregulated during a ketogenic diet (Newman, Verdin 2014). This complementary action between the liver, which produces KBs in periods of shortage of carbs, and the CNS which use them, it’s a very important event which was determinant for the survival of the human species over the millennia. My research focused on three important aspects of KDs and weight loss, which needed further investigation: 1. long-term successful weight loss after a KD: the maintenance of weight loss over long time is challenging and the fear of weight regain is common, so that this phenomenon is named “yo-yo” effect. In this regard, low-carbohydrate diets are known to bring better results compared to low-fat diets in terms of weight loss (Shai, Schwarzfuchs et al. 2008) but not of compliance (Greenberg, Stampfer et al. 2009). Recently, Sumithran and colleagues have demonstrated that the increase in circulating ghrelin and in subjective appetite, which accompanied a hypocaloric diet, was reduced with a ketogenic approach (Sumithran, Prendergast et al. 2013). Thus, we hypothesized that certain aspects of the KD such as muscle mass retention, RMR (resting metabolic rate) and orexigenic hormone stability combined with the acknowledged health benefits of traditional Mediterranean nutrition may favour long-term weight loss. The aim of our study was to investigate the effect on weight and body composition of two short periods of a modified KD, i.e., a very low carbohydrate ketogenic diet with phytoextracts (KEMEPHY) (Paoli, Cenci et al. 2010, Paoli 2011, Paoli 2012) interspersed between longer periods of maintenance nutrition, based on the traditional Mediterranean diet, over a total period of 12 months in obese/overweight healthy subjects and was designed as a retrospective study. We analysed 89 male and female subjects, aged between 25 and 65 years who were overall healthy apart from being obese (mean BMI 35.82 ± 4.11 kg/m2). Data from this study demonstrate that the majority of subjects showed significant weight loss (10%) as a result of a two-phase KD and were compliant both during the six month weight loss phase and the six month normocaloric maintenance phase, with no weight regain. Moreover, the proposed protocol led improvements in health risk factors (total cholesterol, LDL cholesterol, triglycerides and glucose levels) in the majority of subjects. Compliance was very high which was a key determinant of the results seen; 2. formulation of new low-carbohydrate ultraprocessed foods to overcome the lack of sweet taste during a KD: a point of interest, which has always been a detrimental aspect of KDs, is the lack of sweet taste, which could be difficult to sustain for long periods, especially for people with a high sweet food preference. During consumption of a KD, it is mandatory to maintain a low level of glycaemia (about 80–90 mg/dL) to avoid insulin spikes (Paoli, Canato et al. 2011). This condition allows subjects to improve their fat oxidation as demonstrated by Paoli et al. (Paoli, Grimaldi et al. 2012) and by Tagliabue et al. (Tagliabue, Bertoli et al. 2012). Today the new food technology, which is able to build ultra-processed products very low in sugar content and high in protein and fibres, can help to solve this problem, formulating products with a high palatability and ready-to-consume format, useful both in ketosis and in easier low carb diets. Usually, ultra-processed products lack in proteins and fibres and produce postprandial glucose and insulin spikes (PAHO WHO 2015). This effect is known to elicit food craving and overeating, with a preference for high-glycaemic index carbohydrates (high-GI CHO) (Lennerz, Alsop et al. 2013), a phenomenon defined as CHO-craving effect (Ventura, Santander et al. 2014). In order to analyse the effect of 10 different high-protein low-CHO proprietary foods on glycaemia, we recruited 14 healthy females, which were tested for their glycaemic response through the glycaemic score (GS) method. All test foods, compared with glucose, produced a significantly lower glycaemic response and their GS resulted lower than 25 (compared to the reference GS value of glucose which is 100). We concluded that the reformulation of ultraprocessed ready-to-consume foods in a low-CHO, high-protein version can produce a significantly lower glycaemic response whilst maintaining the valued ready-to-use format and high palatability demanded by consumers, facilitating the adherence to a KD of individuals who tend to have a high preference for sweet foods; 3. effect of KDs on cognitive functions: the range of variation of glucose and ketone bodies (KBs) in the blood of non-diabetic individuals is wide and both of them can be used as energy from the brain. Data on glycaemia and ketonemia effects on cognitive functions on healthy humans following different diets are scarce. The purpose of this study was then to compare the effects of glycaemia and ketonemia variation after ten days of two different ketogenic diets and a calorie-restricted Mediterranean diet (MD) on working memory and executive functions in 63 sedentary healthy overweight (BMI>25) young women (age: 20-35), which were recruited in the university area. Subjects were divided in groups according to the day of the beginning of their follicular phase in order to minimize hormonal effects on mood and came for the basal measurements five days before the start of the dietary protocol. The following controls were set on the starting day of the diet (t1), on the third (t3), on the fifth (t5), on the seventh (t7) and on the last day (t10). On the basal control day, the weight of the subjects was measured and a body impedance analysis was performed. Subjects took a standard high carb breakfast and afterwards they completed the psychological tests. At t1, t3, t5, t7 and t10 ketone bodies levels and glycaemia were measured, as well as appetite levels. On the last control day (t10) subjects repeated the body impedance analysis, the body weight measure and, after breakfast (each group had a different breakfast according to the prescribed diet), the psychological tests. Psychological tests consisted in a mood test, two cognitive tasks, one to investigate working memory (visuo-spatial n back) and the second to stress executive functions (inhibitory control task) and in a VAS scale to test the appetite level. 45 subjects completed the study. Considering all participants together, pre-diet glucose levels were positively correlated with reaction time in the go-trial of the executive function test (r(43) = 0.358, p = 0.018), but this relation was not found in the post-diet measure both when subjects were analysed all together and when subjects were divided according to the type of diet followed. In the same psychological test, in the post-diet measure ketonemia showed a negative correlation with accuracy of the no-go trials (r(29) = -0.455, p = 0.027). We can conclude that healthy young overweight subjects with fasting glycaemia below prediabetes level were negatively affected by a high-carb breakfast during an executive function test. Moreover, the effect of mild KBs levels (2 ± 1.3 mmol/L) negatively affected accuracy of the no-go trials of the executive functions test

Clinical characteristics and outcome of ceftazidime/avibactam-resistant Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae infections. A retrospective, observational, 2-center clinical study

Background Recently, Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) with resistance to ceftazidime/avibactam (CZA-R) has been described, including KPC variants that restore carbapenem susceptibility. The aim of the study was to analyze the clinical characteristics and outcomes of infections caused by CZA-R KPC-Kp. Methods From 2019 to 2021, a retrospective 2-center study including patients with infections due to CZA-R KPC-Kp hospitalized at 2 academic hospitals in Rome was conducted. Demographic and clinical characteristics were collected. Principal outcome was 30-day all-cause mortality. Statistical analyses were performed with Stata-IC17 software. Results Overall, 59 patients were included (mean age, 64.4 &amp; PLUSMN; 14.6 years; mean Charlson comorbidity index score, 4.5 &amp; PLUSMN; 2.7). Thirty-four patients (57.6%) had infections caused by CZA-R and meropenem (MEM)-susceptible strains. A previous CZA therapy was observed in 40 patients (67.8%), mostly in patients with MEM-susceptible KPC variant (79.4% vs 52%, P = .026). Primary bacteremia was observed in 28.8%, followed by urinary tract infections and pneumonia. At infection onset, septic shock was present in 15 subjects (25.4%). After adjustment for confounders, only the presence of septic shock was independently associated with mortality (P = .006). Conclusions Infections due to CZA-R KPC-Kp often occur in patients who had previously received CZA, especially in the presence of strains susceptible to MEM. Nevertheless, one-third of patients had never received CZA before KPC-Kp CZA-R. Since the major driver for mortality was infection severity, understanding the optimal therapy in patients with KPC-Kp CZA-R infections is of crucial importance.Clinical characteristics and outcomes of infections caused by ceftazidime/avibactam-resistant (CZA-R) Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae were analyzed. Ceftazidime/avibactam-resistant and meropenem-susceptible KPC variants accounted for more than half of patients. Infections due to CZA-R KPC-Kp often occur in patients who had previously received CZA, especially in the presence of strains susceptible to meropenem. Nevertheless, one-third of patients had never received CZA before isolation of CZA strains. Infection severity was the only independent predictor of 30-day mortality

The effects of different high-protein low-carbohydrates proprietary foods on blood sugar in healthy subjects

The aim of this study was to analyze the effects on blood sugar concentrations through the calculation of the glycemic score (GS) of 10 different high-protein low-carbohydrates (CHOs) proprietary foods that are commonly used as meals during very low-CHO ketogenic diets or during low-CHO diets. Fourteen healthy females were tested for their glycemic response curve elicited by 1000 kJ of glucose three times within a 3-week period (one test each week) compared with one of 10 test foods once on separate days twice a week. After determining the GS of each food in each individual, the mean GS of each test food was calculated. All test foods, compared with glucose, produced a significantly lower glycemic response. The GS of all test food resulted in being lower than 25 and the difference between the mean glycemia after the intake of glucose (mean 122 ± 15 mg/dL) and after the intake of the sweet test foods (mean 89 ± 7 mg/dL) was 33 mg/dL (P < .001), whereas the difference between the mean glycemia after the intake of glucose and after the intake of savory test foods (mean 91 ± 8 mg/dL) was of 31 mg/dL (P < .001). Conclusions: The reformulation of ultraprocessed ready-to-consume foods in a low-CHO, high-protein version can produce a significantly lower glycemic response whilst maintaining the valued ready-to-use format and high palatability demanded by consumers. The low impact on postprandial glycemia and the nutritional characteristics of these proprietary foods makes them useful in both weight control management strategies and in the care management of diabetes

Influence of Storage Temperature on Radiochemical Purity of 99mTc-Radiopharmaceuticals

The influence of effective room temperature on the radiochemical purity of 99mTc-radiopharmaceuticals was reported. This study was born from the observation that in the isolators used for the preparation of the 99mTc-radiopharmaceuticals the temperatures can be higher than those reported in the commercial illustrative leaflets of the kits. This is due, in particular, to the small size of the work area, the presence of instruments for heating, the continuous activation of air filtration, in addition to the fact that the environment of the isolator used for the 99mTc-radiopharmaceuticals preparation and storage is completely isolated and not conditioned. A total of 244 99mTc-radiopharmaceutical preparations (seven different types) have been tested and the radiochemical purity was checked at the end of preparation and until the expiry time. Moreover, we found that the mean temperature into the isolator was significantly higher than 25 C, the temperature, in general, required for the preparation and storage of 99mTc-radiopharmaceuticals. Results confirmed the radiochemical stability of radiopharmaceutical products. However, as required in the field of quality assurance, the impact that different conditions than those required by the manufacturer on the radiopharmaceuticals quality have to be verified before human administration

Analysis of a Flexible Dual-Channel Octagonal Coil System for UHF MRI

Nowadays, MRI is focused on using ultra-high static magnetic fields (&gt; 7 T) to increase the signal-to-noise ratio. The use of high fields, on the other hand, requires novel technical solutions as well as more stringent design criteria for specific absorption rate levels, reducing radiative effect and coil resistance. In this paper, two flexible RF coils for 7 T human magnetic resonance, and 298 MHz ultra-high frequency operations were analyzed and characterized. Imaging of lower human limbs is regarded as a case study. The lumped element theory and subsequent numerical simulations were used to fine-tune the single-coil element and the dual-coil array design, respectively. Here, we demonstrate how the shape, size, configuration, and presence of the sample influence the coil performance. The penetration depth of the B 1 -field and the specific absorption rate values have been determined numerically using two numerical surface phantoms: saline and a multilayer human tissue. A preliminary study in the presence of a saline solution phantom has been carried out to develop and validate the dual-coil system. The frequency response of the dual-coil array was measured to assess its robustness when coupled to twelve human volunteers. We found that our design is robust to variations in the anatomical properties of the human thighs, and hence to coil bending. The presented approach can be useful for the implementation of flexible devices with high sensitivity levels and low specific absorption rat

Resistance to Ceftazidime/Avibactam in Klebsiella pneumoniae KPC-Producing Isolates: A Real-Life Observational Study

Background: Ceftazidime/avibactam (CAZ-AVI) resistance amongst Enterobacterales is worryingly increasing worldwide. Objectives: The aim of this study was to collect and describe real-life data on CAZ-AVI-resistant Klebsiella pneumoniae (KP) isolates in our University Hospital, with the ultimate goal of evaluating possible risk factors related to the acquisition of resistance. Methods: This is a retrospective observational study, including unique Klebsiella pneumoniae (KP) isolates resistant to CAZ-AVI (CAZ-AVI-R) and producing only KPC, collected from July 2019 to August 2021 at Policlinico Tor Vergata, Rome, Italy. The pathogen's list was obtained from the microbiology laboratory; clinical charts of the corresponding patients were reviewed to collect demographic and clinical data. Subjects treated as outpatients or hospitalized for &lt;48 h were excluded. Patients were then divided into two groups: S group, if they had a prior isolate of CAZ-AVI-susceptible KP-KPC, and R group, if the first documented isolate of KP-KPC was resistant to CAZ-AVI. Results: Forty-six unique isolates corresponding to 46 patients were included in the study. The majority of patients (60.9%) were hospitalized in an intensive care unit, 32.6% in internal medicine wards and 6.5% in surgical wards. A total of 15 (32.6%) isolates were collected from rectal swabs, representing a colonization. Amongst clinically relevant infections, pneumonia and urinary tract infections were the most commonly found (5/46, 10.9% each). Half of the patients received CAZ-AVI prior to isolation of the KP-KPC CAZ-AVI-R (23/46). This percentage was significantly higher in patients in the S group compared to patients in the R group (69.3% S group vs. 25% R group, p = 0.003). No differences between the two groups were documented in the use of renal replacement therapy or in the infection site. The clinically relevant CAZ-AVI-R KP infections (22/46, 47.8%) were all treated with a combination therapy, 65% including colistin and 55% including CAZ-AVI, with an overall clinical success of 38.1%. Conclusions: Prior use of CAZ-AVI was associated with the emergence of drug resistance

Medium term effects of a ketogenic diet and a Mediterranean diet on resting energy expenditure and respiratory ratio

none6noneAntonio Paoli;Keith Grimaldi;Antonino Bianco;Alessandra Lodi;Lorenzo Cenci;Andrea ParmagnaniPaoli, Antonio; Keith, Grimaldi; Antonino, Bianco; Lodi, Alessandra; Lorenzo, Cenci; Parmagnani, Andre

Detection Analysis and Study of Genomic Region Variability of JCPyV, BKPyV, MCPyV, HPyV6, HPyV7 and QPyV in the Urine and Plasma of HIV-1-Infected Patients

Since it was clearly established that HIV/AIDS predisposes to the infection, persistence or reactivation of latent viruses, the prevalence of human polyomaviruses (HPyVs) among HIV-1-infected patients and a possible correlation between HPyVs and HIV sero-status were investigated. PCR was performed to detect and quantify JCPyV, BKPyV, MCPyV, HPyV6, HPyV7 and QPyV DNA in the urine and plasma samples of 103 HIV-1-infected patients. Subsequently, NCCR, VP1 and MCPyV LT sequences were examined. In addition, for MCPyV, the expression of transcripts for the LT gene was investigated. JCPyV, BKPyV and MCPyV’s presence was reported, whereas HPyV6, HPyV7 and QPyV were not detected in any sample. Co-infection patterns of JCPyV, BKPyV and MCPyV were found. Archetype-like NCCRs were observed with some point mutations in plasma samples positive for JCPyV and BKPyV. The VP1 region was found to be highly conserved among these subjects. LT did not show mutations causing stop codons, and LT transcripts were expressed in MCPyV positive samples. A significant correlation between HPyVs’ detection and a low level of CD4+ was reported. In conclusion, HPyV6, HPyV7 and QPyV seem to not have a clinical relevance in HIV-1 patients, whereas further studies are warranted to define the clinical importance of JCPyV, BKPyV and MCPyV DNA detection in these subjects

Multiparametric MRI dataset for susceptibility-based radiomic feature extraction and analysis

Multiple sclerosis (MS) is a progressive demyelinating disease impacting the central nervous system. Conventional Magnetic Resonance Imaging (MRI) techniques (e.g., T2w images) help diagnose MS, although they sometimes reveal non-specific lesions. Quantitative MRI techniques are capable of quantifying imaging biomarkers in vivo, offering the potential to identify specific signs related to pre-clinical inflammation. Among those techniques, Quantitative Susceptibility Mapping (QSM) is particularly useful for studying processes that influence the magnetic properties of brain tissue, such as alterations in myelin concentration. Because of its intrinsic quantitative nature, it is particularly well-suited to be analyzed through radiomics, including techniques that extract a high number of complex and multi-dimensional features from radiological images. The dataset presented in this work provides information about normal-appearing white matter (NAWM) in a cohort of MS patients and healthy controls. It includes QSM-based radiomic features from NAWM and its tracts, and MR sequences necessary to implement the pipeline: T1w, T2w, QSM, DWI. The workflow is outlined in this article, along with an application showing feature reliability assessment

Deciphering OPA1 mutations pathogenicity by combined analysis of human, mouse and yeast cell models

OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA) and the syndromic form DOA “plus”. Over 370 OPA1 mutations have been identified so far, although their pathogenicity is not always clear. We have analyzed one novel and a set of known OPA1 mutations to investigate their impact on protein functions in primary skin fibroblasts and in two “ad hoc” generated cell systems: the MGM1/OPA1 chimera yeast model and the Opa1−/− MEFs model expressing the mutated human OPA1 isoform 1. The yeast model allowed us to confirm the deleterious effects of these mutations and to gain information on their dominance/recessivity. The MEFs model enhanced the phenotypic alteration caused by mutations, nicely correlating with the clinical severity observed in patients, and suggested that the DOA “plus” phenotype could be induced by the combinatorial effect of mitochondrial network fragmentation with variable degrees of mtDNA depletion. Overall, the two models proved to be valuable tools to functionally assess and define the deleterious mechanism and the pathogenicity of novel OPA1 mutations, and useful to testing new therapeutic interventions