Associations between continuous glucose monitoring (CGM) metrics and psycholinguistic measures: a correlational study

AIM

Recently, the relationship between diabetes and mental health has been widely studied. With the advent of continuous glucose monitoring (CGM), some researchers have been interested in exploring the association between glucose-related metrics and psychological aspects. These studies have primarily relied on self-report questionnaires which present some limitations. Therefore, the present multicenter study aims at testing potential associations between CGM metrics and affective processes derived from narratives about using a CGM sensor.

METHODS

An exploratory correlational design was used. Fifty-eight adults with type 1 diabetes using CGM were enrolled and invited to complete an online survey, where they replied to an open-ended question regarding their personal experience with the CGM sensor. Texts derived from the answers were analyzed through Linguistic Inquiry and Word Count, a widely used text analysis tool that can automatically identify and quantify linguistic patterns related to various psychological dimensions. Psycholinguistic measures were correlated with CGM metrics.

RESULTS

Higher levels of sadness/depression correlated with lower %TIR (r = - 339; p < .01) and higher %TAR (r = .342; p < .01).

CONCLUSIONS

The study highlights the relationship between CGM metrics and psychological variables derived from patients' narratives. In particular, it is possible to hypothesize a positive role of %TIR in reducing depressive feelings in individuals with diabetes, as well as a negative role of depressive feelings in achieving desirable CGM outcomes. Additionally, there is a potential role of glycemic variability, particularly hyperglycemia, in the expression of depressive and sad feelings, which has been less studied compared to the effects of hypoglycemia.

Evaluation of endocrinological sequelae following particle therapy performed on anterior skull base lesions in the adult population

Background

Radiotherapy has increasingly assumed a central role in the multidisciplinary treatment of skull base lesions. Unfortunately, it is often burdened by relevant radio-induced damage to the pituitary function and the surrounding structures and systems. Patients who were treated with radiotherapy around the sellar region especially have a high risk of developing radio-induced hypopituitarism. Particle therapy has the potential advantage of delivering a higher radiation dose to the target while potentially sparing the sellar region and pituitary function. The aim of this study is to evaluate the pituitary function in adult patients who have undergone hadron therapy for anterior skull base lesions involving or surrounding the pituitary gland.

Methods

This is a retrospective, observational, and noncontrolled study. We evaluated pituitary and peripheral hormone levels in all patients referring to National Center for Oncological Hadrontherapy, Pavia, Italy for anterior skull base tumors. Furthermore, we performed a magnetic resonance imaging for every follow-up to evaluate potential tumoral growth.

Results

We evaluated 32 patients with different tumoral lesions with a mean follow-up of 27.9 months. The mean hadron therapy (HT) dose was 60 ± 14 Gray, with a mean dose per fraction of 2.3 ± 2.1 Gray. Six patients were treated with carbon ions and 26 with protons. Pituitary hormone alteration of some kind was reported for six patients. No patient experienced unexpected severe adverse events related to particle therapy.

Conclusion

Particle radiotherapy performed on anterior skull base lesions has proved to cause limited damage to pituitary function in the adult population.

Domiciliary Management of Periodontal Indexes and Glycosylated Hemoglobin (HbA1c) in Type 1 Diabetic Patients with Paraprobiotic-Based Toothpaste and Mousse: Randomized Clinical Trial

Background: Periodontal disease is a chronic inflammation of periodontal tissues. Several systemic diseases are related to this condition. One of the strongest associations is that of periodontitis and type 2 diabetes mellitus (T2DM). On the contrary, the link with type 1 diabetes mellitus (T1DM) has not been extensively investigated. The objective of the present report is to evaluate and compare the effect of two domiciliary oral hygiene protocols on the periodontal clinical status as well as on the metabolic control in patients affected by T1DM. Methods: Sample size calculation required 20 patients per group, therefore 40 patients were equally and randomly assigned to the following home oral care protocols: a probiotic-based one (trial group) and a natural extracts-based one (control group). At the beginning of the study, after 3 and 6 months, the following periodontal indexes were collected: Probing Pocket Depth (PPD), Plaque Index (PI), Clinical Attachment Level (CAL), Bleeding on Probing (BoP), and Glycosylated Hemoglobin (HbA1c). Data underwent statistical analysis (significance threshold: p < 0.05). Results: In both groups, significant decreases in the periodontal clinical indexes were found at various time frames, whereas the levels of HbA1c significantly decreased only in the control group. Conclusions: Both the domiciliary treatments administered can significantly improve PPD, PI, CAL, and BOP parameters, whereas only the natural extracts-based gel seems to decrease HbA1c levels of T1DM patients.

Impact of COVID-19 in immunosuppressive drug-naïve autoimmune disorders: Autoimmune gastritis, celiac disease, type 1 diabetes, and autoimmune thyroid disease

Few conflicting data are currently available on the risk of SARS-CoV-2 infection in patients with autoimmune disorders. The studies performed so far are influenced, in most cases, by the treatment with immunosuppressive drugs, making it difficult to ascertain the burden of autoimmunity per se. For this reason, herein we assessed the susceptibility to COVID-19 in immunosuppressive drug-naïve patients with autoimmune diseases, such as autoimmune gastritis (AIG), celiac disease (CD), type 1 diabetes (T1D), and autoimmune thyroid disease (AITD). Telephone interviews were conducted on 400 patients-100 for each group-in May 2021 by looking at the positivity of molecular nasopharyngeal swabs and/or serology for SARS-CoV-2, the need for hospitalization, the outcome, and the vaccination status. Overall, a positive COVID-19 test was reported in 33 patients (8.2%), comparable with that of the Lombardy general population (8.2%). In particular, seven patients with AIG, 9 with CD, 8 with T1D, and 9 with AITD experienced COVID-19. Only three patients required hospitalization, none died, and 235 (58.7%) were vaccinated, 43 with AIG, 47 with CD, 91 with T1D, and 54 with AITD. These results seem to suggest that autoimmunity per se does not increase the susceptibility to COVID-19. Also, COVID-19 seems to be mild in these patients, as indicated by the low hospitalization rates and adverse outcomes, although further studies are needed to better clarify this issue.

Telemedicine and urban diabetes during COVID-19 pandemic in Milano, Italy during lock-down: epidemiological and sociodemographic picture

BACKGROUND

Since 2010, more than half of World population lives in Urban Environments. Urban Diabetes has arisen as a novel nosological entity in Medicine. Urbanization leads to the accrual of a number of factors increasing the vulnerability to diabetes mellitus and related diseases. Herein we report clinical-epidemiological data of the Milano Metropolitan Area in the contest of the Cities Changing Diabetes Program. Since the epidemiological picture was taken in January 2020, on the edge of COVID-19 outbreak in the Milano Metropolitan Area, a perspective addressing potential interactions between diabetes and obesity prevalence and COVID-19 outbreak, morbidity and mortality will be presented. To counteract lock-down isolation and, in general, social distancing a pilot study was conducted to assess the feasibility and efficacy of tele-monitoring via Flash Glucose control in a cohort of diabetic patients in ASST North Milano.

METHODS

Data presented derive from 1. ISTAT (National Institute of Statistics of Italy), 2. Milano ATS web site (Health Agency of Metropolitan Milano Area), which entails five ASST (Health Agencies in the Territories). A pilot study was conducted in 65 screened diabetic patients (only 40 were enrolled in the study of those 36 were affected by type 2 diabetes and 4 were affected by type 1 diabetes) of ASST North Milano utilizing Flash Glucose Monitoring for 3 months (mean age 65 years, HbA1c 7,9%. Patients were subdivided in 3 groups using glycemic Variability Coefficient (VC): a. High risk, VC > 36, n. 8 patients; Intermediate risk 20 < VC < 36, n. 26 patients; Low risk VC < 20, n. 4 patients. The control group was constituted by 26 diabetic patients non utilizing Flash Glucose monitoring.

RESULTS

In a total population of 3.227.264 (23% is over 65 y) there is an overall prevalence of 5.65% with a significant difference between Downtown ASST (5.31%) and peripheral ASST (ASST North Milano, 6.8%). Obesity and overweight account for a prevalence of 7.8% and 27.7%, respectively, in Milano Metropolitan Area. We found a linear relationship (R = 0.36) between prevalence of diabetes and aging index. Similarly, correlations between diabetes prevalence and both older people depending index and structural dependence index (R = 0.75 and R = 0.93, respectively), were found. A positive correlation (R = 0.46) with percent of unoccupied people and diabetes prevalence was also found. A reverse relationship between diabetes prevalence and University level instruction rate was finally identified (R = - 0.82). Our preliminary study demonstrated a reduction of Glycated Hemoglobin (p = 0.047) at 3 months follow-up during the lock-down period, indicating Flash Glucose Monitoring and remote control as a potential methodology for diabetes management during COVID-19 lock-down.

HYPOTHESIS AND DISCUSSION

The increase in diabetes and obesity prevalence in Milano Metropolitan Area, which took place over 30 years, is related to several environmental factors. We hypothesize that some of those factors may have also determined the high incidence and virulence of COVID-19 in the Milano area. Health Agencies of Milano Metropolitan Area are presently taking care of diabetic patients facing the new challenge of maintaining sustainable diabetes care costs in light of an increase in urban population and of the new life-style. The COVID-19 pandemic will modify the management of diabetic and obese patients permanently, via the implementation of approaches that entail telemedicine technology. The pilot study conducted during the lock-down period indicates an improvement of glucose control utilizing a remote glucose control system in the Milano Metropolitan Area, suggesting a wider utilization of similar methodologies during the present "second wave" lock-down.

Abnormal post-prandial glucagon-like peptide release in patients with Crohn's disease

BACKGROUND AND AIMS

Glucagon-like peptide GLP-1 and -2 have been shown to regulate immune responses in immune-mediated disorders, including Crohn's disease (CD). Our aim was to investigate post-prandial GLP release and its potential link to chronic inflammation, insulin secretion/sensitivity and body composition changes in CD patients.

METHODS

Fifteen patients with CD, 15 healthy controls (HC) and 15 patients with metabolic syndrome (MS) were recruited. All patients underwent assessment of body composition by means of bio-impedance followed by a meal tolerance test (MTT). Only one CD patient did not tolerate the MTT and was excluded.

RESULTS

Basal GLP-1 levels were up-regulated in CD, however, as compared to HC, stimulated GLP-1 secretion was significantly reduced in CD (-31 %, p < 0.05) as in MS (-52 %, p < 0.003). Similarly, basal GLP-2 levels were comparable to that of HC, while response to MTT in CD was virtually absent (p < 0.05). Similar fasting insulin sensitivity, estimated 1^st and 2^nd phase insulin secretion and insulinogenic index were found in CD and in HC. Post-prandial GLP secretion was positively correlated to insulin secretion indices, both in CD and MS. In CD, high-sensitive C reactive protein levels (hsCRP) and extra-cellular to intra-cellular water ratio (ECW/ICW), an index of cellular inflammation, were inversely correlated with stimulated GLP-1 (p < 0.05 and p < 0.01, respectively) levels.

CONCLUSION

CD is characterized by abnormal fasting and post-prandial GLP levels. Circulating GLP influences subclinical inflammation and glucose metabolism in CD patients, but not their body composition parameters.

Sitagliptin Treatment at the Time of Hospitalization Was Associated With Reduced Mortality in Patients With Type 2 Diabetes and COVID-19: A Multicenter, Case-Control, Retrospective, Observational Study

OBJECTIVE

Poor outcomes have been reported in patients with type 2 diabetes and coronavirus disease 2019 (COVID-19); thus, it is mandatory to explore novel therapeutic approaches for this population.

RESEARCH DESIGN AND METHODS

In a multicenter, case-control, retrospective, observational study, sitagliptin, an oral and highly selective dipeptidyl peptidase 4 inhibitor, was added to standard of care (e.g., insulin administration) at the time of hospitalization in patients with type 2 diabetes who were hospitalized with COVID-19. Every center also recruited at a 1:1 ratio untreated control subjects matched for age and sex. All patients had pneumonia and exhibited oxygen saturation <95% when breathing ambient air or when receiving oxygen support. The primary end points were discharge from the hospital/death and improvement of clinical outcomes, defined as an increase in at least two points on a seven-category modified ordinal scale. Data were collected retrospectively from patients receiving sitagliptin from 1 March through 30 April 2020.

RESULTS

Of the 338 consecutive patients with type 2 diabetes and COVID-19 admitted in Northern Italy hospitals included in this study, 169 were on sitagliptin, while 169 were on standard of care. Treatment with sitagliptin at the time of hospitalization was associated with reduced mortality (18% vs. 37% of deceased patients; hazard ratio 0.44 [95% CI 0.29-0.66]; P = 0.0001), with an improvement in clinical outcomes (60% vs. 38% of improved patients; P = 0.0001) and with a greater number of hospital discharges (120 vs. 89 of discharged patients; P = 0.0008) compared with patients receiving standard of care, respectively.

CONCLUSIONS

In this multicenter, case-control, retrospective, observational study of patients with type 2 diabetes admitted to the hospital for COVID-19, sitagliptin treatment at the time of hospitalization was associated with reduced mortality and improved clinical outcomes as compared with standard-of-care treatment. The effects of sitagliptin in patients with type 2 diabetes and COVID-19 should be confirmed in an ongoing randomized, placebo-controlled trial.

Clinical use of a 180-day implantable glucose sensor improves glycated haemoglobin and time in range in patients with type 1 diabetes

AIMS

This real-world study evaluated the changes in glycated haemoglobin (HbA1c) and continuous glucose monitoring (CGM) metrics associated with use of the implantable 180-day Eversense CGM System (Eversense) in patients with type 1 diabetes.

MATERIALS AND METHODS

This was a prospective, multicentre, observational study among adult participants aged ≥18 years with type 1 diabetes across seven diabetes-care centres in Italy who had Eversense inserted for the first time. HbA1c was measured at baseline and at 180 days. Changes in time in range [TIR (glucose 70-180 mg/dL)], time above range [TAR (glucose >180 mg/dL)], time below range [TBR (glucose <70 mg/dL)] and glycaemic variability were also assessed. Data were also analysed by previous CGM use and by mode of insulin delivery.

RESULTS

One-hundred patients were enrolled (mean age 36 ± 12 years, mean baseline HbA1c 7.4 ± 0.92% [57 ± 10 mmol/mol]). Fifty-six per cent of patients were users of the continuous subcutaneous insulin infusion pump and 45% were previous users of CGM. HbA1c significantly decreased in patients after 180 days of sensor wear (-0.43% ± 0.69%, 5 ± 8 mmol/mol, P < 0.0001). As expected, CGM-naïve patients achieved the greatest reduction in HbA1c (-0.74% ± 0.48%, 8 ± 5 mmol/mol). TIR significantly increased and TAR and mean daily sensor glucose significantly decreased while TBR did not change after 180 days of sensor wear.

CONCLUSIONS

Real-world clinical use of the Eversense CGM System for 180 days was associated with significant improvements in HbA1c and CGM metrics among adults with type 1 diabetes. The study is registered on clinicaltrials.gov (NCT04160156).

Metabolic control and complications in Italian people with diabetes treated with continuous subcutaneous insulin infusion

BACKGROUND AND AIM

The objective of this cross-sectional study was to evaluate the degree of glycaemic control and the frequency of diabetic complications in Italian people with diabetes who were treated with continuous subcutaneous insulin infusion (CSII).

METHODS AND RESULTS

Questionnaires investigating the organisation of diabetes care centres, individuals' clinical and metabolic features and pump technology and its management were sent to adult and paediatric diabetes centres that use CSII for treatment in Italy. Information on standard clinical variables, demographic data and acute and chronic diabetic complications was derived from local clinical management systems. The sample consisted of 6623 people with diabetes, which was obtained from 93 centres. Of them, 98.8% had type 1 diabetes mellitus, 57.2% were female, 64% used a conventional insulin pump and 36% used a sensor-augmented insulin pump. The median glycated haemoglobin (HbA_1c) level was 60 mmol/mol (7.6%). The HbA_1c target (i.e. <58 mmol/mol for age <18 years and <53 mmol/mol for age >18 years) was achieved in 43.4% of paediatric and 23% of adult participants. Factors such as advanced pump functions, higher rate of sensor use, pregnancy in the year before the study and longer duration of diabetes were associated with lower HbA_1c levels. The most common chronic complications occurring in diabetes were retinopathy, microalbuminuria and hypertension. In the year before the study, 5% of participants reported ≥1 episode of severe hypoglycaemic (SH) episodes (SH) and 2.6% reported ≥1 episode of ketoacidosis.

CONCLUSIONS

Advanced personal skills and use of sensor-based pump are associated with better metabolic control outcomes in Italian people with diabetes who were treated with CSII. The reduction in SH episodes confirms the positive effect of CSII on hypoglycaemia.

CLINICAL TRIAL REGISTRATION NUMBER

NCT 02620917 (ClinicalTrials.gov).

ACTH-dependent Cushing's Syndrome: Diagnostic Pitfalls in Concomitant Non-secreting Pituitary Adenomas

Objectives

To describe the possible pitfalls in correctly interpreting clinical, radiological and biochemical findings in ACTH-dependent Cushing’s syndrome.

Methods

We describe a case of a pituitary adenoma visualized at MRI not correlated with an ACTH-dependent Cushing’s syndrome.

Results

Radiological imaging and hormonal testing can be misleading in suspected pituitary ACTH-related Cushing’s syndrome.

Conclusion

Correct interpretation of the initial clinical presentation can help in the proper diagnosis and treatment of ACTH-dependent Cushing’s syndrome.

LEARNING POINTS

Haemorrhagic presentation of a craniopharyngioma in a pregnant woman

Objective. Craniopharyngioma is a rare tumour, and, consequently, acute clinical presentation and diagnosis, during pregnancy, of this pathology are quite difficult to find. Only few cases are reported in the literature, and no one describes these two conditions in association. Methods. We report a particular case of craniopharyngioma presenting both of the above conditions. Results. The patient was successfully operated with endoscopic technique. Conclusions. Rare and difficult cases, created by the superposition of different clinical conditions, need multidisciplinary management, with collaboration, integration, and cooperation between different medical specialists.

Effects of uncomplicated vaginal delivery and epidural analgesia on fetal arterial acid-base parameters at birth in gestational diabetes

AIM

To investigate the effects of uncomplicated vaginal delivery and epidural analgesia on fetal acid-base parameters in women with gestational diabetes (GDM) compared with controls.

METHODS

A retrospective case-control study of 142 women with gestational diabetes and 284 controls. To evaluate the effect of diabetes and analgesia on acid-base status correcting for potential confounders we used ordered logistic equations including quartiles of fetal arterial acid-base parameters collected at birth as outcomes and categories of diabetes and epidural analgesia as explanatory variables.

RESULTS

In the GDM group cord base deficit (-2.63 mmol/l, interquartile range [IQR]=4.2 to -0.65 mmol/l vs. -1.9 mmol/l, IQR=-3.3 to -0.2 mmol/l, p=0.009, odds ratio (OR)=1.51, 95% confidence interval (CI)=1.04-2.18) was lower and concentration of calcium higher (1.49 mmol/l, IQR=1.42-1.56 mmol/l vs. 1.47 mmol/l, IQR=1.41-1.51 mmol/l, p=0.009, OR=1.69, 95% CI=1.12-2.56) compared with controls. Epidural analgesia in the GDM group was associated with reduced cord concentration of glucose (84.0mg/dl [4.7 mmol/l], IQR=70-103.3mg/dl vs. 92.5mg/dl [5.1 mmol/l], IQR=76.5-121.8 mg/dl, p=0.004), lactate (2.65 mmol/l (IQR=1.80-4.20) vs. 3.70 mmol/l (IQR=2.90-5.55 mmol/l), p=0.002) and less pronounced base deficit (-2.05 mmol/l, IQR=-3.90 to -0.17 mmol/l vs. -2.8, IQR=-5.57 to -1.05 mmol/l, p=0.01, OR=0.7, 95% CI=0.49-0.99).

CONCLUSIONS

In uncomplicated pregnancies and deliveries, well-controlled gestational diabetes mellitus has potentially significant detrimental effects on fetal acid-base status at birth. Epidural analgesia reduces cord arterial glucose and lactates.

Gestational diabetes mellitus: including serum pregnancy-associated plasma protein-A testing in the clinical management of primiparous women? A case-control study

AIMS

To assess pregnancy-associated plasma protein A (PAPP-A) correlation with GDM and its usefulness in predicting GDM in primiparous women.

METHODS

First trimester data related to 307 pregnant women affected by GDM and 366 control pregnant women were retrieved from a computer data base and integrated with ad hoc data. Clinical data were recorded at delivery. A logistic model was used to analyze the association between first trimester data and subsequent clinical outcomes. We derived a risk score using both classical risk factors for GDM and PAPP-A.

RESULTS

Diabetic and control women were significantly different in terms of age (p<0.001), BMI (p<0.001), weight (p<0.001), family history of diabetes (p<0.001), PAPP-A concentration and PAPP-A corrected multiple of the median (MoM) (p<0.001). The ROC-AUC of the clinical risk score was 0.60 (95%CI 0.56-0.64), the adjusted score including PAPP-A MoM was 0.70 (95%CI 0.66-0.74).

CONCLUSIONS

Low PAPP-A was strongly associated with GDM and lower values were found in diabetic women needing insulin therapy. Adding PAPP-A to first trimester screening could improve the prediction of women at high risk who will develop GDM. Further studies are needed to validate the applicability of our findings in different populations and settings.

Silent familial isolated pituitary adenomas: histopathological and clinical case report

Familial isolated pituitary adenoma (FIPA) is a rare condition independent of Carney Complex or MEN1. An international multicenter study recently described 28 nonfunctioning pituitary adenomas in 26 families with only two homogeneous nonsecreting phenotype families consistent of silent GH and silent gonadotroph adenomas, respectively. We present the clinical, genetic, and morphological analysis of two silent pituitary adenomas occurring in a man and his daughter, and discuss the differential diagnosis associated with their histological, immunohistochemical, and ultrastructural features. The patients developed invasive nonsecreting macroadenomas manifesting only with compressive symptoms. Genetic analysis in the father showed no MEN-1 germ-line mutation. Tissue samples obtained after paraseptal trans-sphenoidal surgery were studied by immunohistochemistry for adenohypophyseal hormones, low molecular weight cytokeratins (CAM 5.2), proliferation markers, and anterior pituitary transcription factors (Pit-1 and SF-1) and by electron microscopy for secretory granules. The clinical, histological, and immunohistochemical features of the lesions posed a differential diagnosis between a null cell adenoma and a silent corticotroph adenoma (Type II); on the basis of immunohistochemical stains for cytokeratin and adenohypophysis cell lineage markers, tumor behavior and ultrastructural studies we concluded for the second. The reported cases represent an as yet undescribed example of homogeneous family with silent corticotroph adenomas (Type II). Our observations support the trend for more aggressive behavior in nonsecreting FIPAs as compared with sporadic adenomas.

Inhibition of cyclooxygenase as potential novel therapeutic strategy in N141I presenilin-2 familial Alzheimer's disease

The present study was designed to further explore the potential cause/effect relationship between the expression of both the N141I presenilin (PS)2 mutant familial Alzheimer's disease (FAD) gene and cyclooxgenase (COX) in respect to the mechanism associated with programmed cell death in Alzheimer's disease (AD). We found that expression of mutant N141I PS2 resulting in apoptotic cell death in H4 neuronal cells coincided with >4-fold induction in the expression of the inducible form of COX-2, but not the constitutive COX-1. Moreover, we found that the expression of the N141I PS2 FAD gene strongly promoted (>2-fold) glycogen synthase kinase (GSK)-3beta activity coincidental with a reduction in the level of beta-catenin translocated from the cytoplasmic to the nuclear compartment. Most interestingly, we found that inhibition of COX-2-mediated generation of prostaglandin (PG)-E2 in H4 neuronal cells with the preferential COX-2 inhibitor nimesulide protects against N141I PS2-mediated apoptotic cell death coincidental with an inhibition of GSK-3beta activity and subsequent normalization of beta-catenin cellular distribution. The clinical relevance of this finding was confirmed by the evidence that COX-2 protein and PG-E2 concentrations were selectively increased >2-fold in the cerebral cortex of subjects harboring the N141I PS2 FAD mutation relative to wild-type PS2 AD cases. This study demonstrates for the first time that COX-2 may be a downstream effector of mutant N141I PS2-mediated apoptotic cell death and that inhibition of COX-2 may neuroprotect in AD through modulation of a GSK-3beta-beta-catenin-mediated response. The study provides support for the potential pharmacogenomic identification of N141I PS2 FAD cases that might preferentially benefit from inhibition of COX-2 during the progression of clinical dementia.

Phosphorylation of tau at THR212 and SER214 in human neuronal and glial cultures: the role of AKT

We have reported recently that the microtubule-associated protein tau is phosphorylated in vitro by Akt, an important kinase in anti-apoptotic signaling regulated by insulin and growth factors. We also established that Akt phosphorylates tau separately at T212 and S214, two sites previously shown to be phosphorylated by glycogen synthase kinase 3beta (GSK3beta) and protein kinase A (PKA), respectively. In the present studies, we examined the relationship between Akt and T212/S214 in primary cultures of human neurons and astrocytes, and evaluated the contribution of two other kinases. In intact cells, we found a very low content of active (phospho-S473) form of Akt. We also found a low content of phospho-S214 but not phospho-T212 of tau, suggesting that only phospho-S212 may depend on Akt activity in situ. We upregulated Akt activity using two experimental models: treatment with a protein phosphatase inhibitor, okadaic acid, and transfection with a constitutively active Akt gene construct (c-Akt). Under these conditions, phosphorylation of tau at T212 and S214 was regulated independently, with little change or downregulation of phospho-T212 and dynamic upregulation of phospho-S214. Our studies revealed that Akt may influence the phospho-S214 content in a meaningful manner. They also revealed that PKA may only partially contribute to the phosphorylation of S214. In comparison, okadaic acid treatment severely depleted the content of GSK3beta and downregulated the remaining GSK3beta activity by Akt-dependent inhibition, consistent with minimal changes in phospho-T212. In summary, these results strongly suggest that in primary cultures, Akt selectively phosphorylates tau at S214 rather than T212. Our studies raise the possibility that tau S214 may participate in Akt-mediated anti-apoptotic signaling.

[Role of high resolution color-Doppler US of the sentinel node in patients with stage I melanoma]

PURPOSE

The aims of the present work are to assess the diagnostic accuracy of high resolution color Doppler ultrasound (US) of the sentinel node (SN) in patients with cutaneous melanoma skin at stage I. The US findings of nodal involvement could spare the patient a surgical step (selective lymphaderectomy) allowing them to undergo radical lymphadenectomy directly.

MATERIAL AND METHODS

From November 1998 to November 2000 94 patients (mean age 52.7 years) underwent lymphoscintigraphy in order to mark the SN site on their skin. An US scan (112 lymphatic basins) was performed within 24 hours with a 10-13 MHz electronic linear probe with color-power-Doppler (Esaote AU5 Idea Scanner, Genoa, Italy). The sonographic features we analysed were: shape (roundness index), hilum displacement, intranodal heterogenicity, eccentric cortical thickness, extranodal invasion, vessel irregularity.

RESULTS

26 nodes showed US findings consistent with malignant involvement, 86 were negative. All the nodes were surgically removed and controlled by histology. Sensitivity and specificity of US scanning were 89.4% and 90.3%, the positive and negative predictive values 65.3% and 97.6%, respectively. US correctly identified the involved SN in 15,1% cases, so that 17 patients could have avoided the selective lymphadenectomy

CONCLUSION

Preoperative lymphoscintigraphy and high-resolution color-Doppler US scanning constitute a useful diagnostic tool in identifying the metastatic SN, with a low margin of error. False negatives were technically induced, even using the more recent scanners, by the low US probe resolution, unable to recognise metastatic microdeposits. The two most reliable parameters in identifying involved lymphnodes were the roundness index and the absence of hilar echo. The advent of technologically more advanced probes should allow better spatial resolution and assessment of lymph node vascularization, enabling diagnosis of metastasis measuring less than 2 mm in diameter.

Genetic polymorphisms of the renin-angiotensin-aldosterone system in end-stage renal disease

BACKGROUND

Hypertension contributes to the progression to renal failure. A genetic susceptibility to hypertension may predispose to the development of end-stage renal disease (ESRD) and promote a more rapid progression to ESRD in patients with renal diseases. Genes encoding for angiotensinogen (AGT), angiotensin-converting enzyme (ACE), and aldosterone synthase (CYP11B2) are candidates for abnormal blood pressure regulation.

METHODS

Genotyping was performed in 327 control subjects and 260 ESRD patients for the M235T-AGT, the insertion/deletion (I/D)-ACE, and the -344T/C-CYP11B2 gene polymorphisms using polymerase chain reaction, gel analysis, and appropriate restriction digest when required.

RESULTS

Genotype frequencies did not differ significantly between ESRD patients and controls. When ESRD diabetic subjects were compared with diabetic patients without nephropathy, the prevalence of the AGT-MM genotype was lower (28.1 vs. 52.8%, P < 0.01), while the AGT-TT genotype was higher (15.6 vs. 2.7%, P < 0.05). The AGT-TT genotype was associated with a faster progression to ESRD in patients with glomerulonephritis (P < 0.05). In the total ESRD population, progression of renal disease was faster with the ACE-DD than with the DI and II alleles (P < 0.05). This association was particularly strong when the interaction with the AGT genotype was analyzed, with a rapid progression in ACE-DD as compared with ACE-DI and II in patients with the AGT-MM genotype (P < 0.01).

CONCLUSIONS

Susceptibility for ESRD and faster progression to ESRD are linked with the AGT genotype in diabetic patients. Faster progression to ESRD is associated with the ACE genotype when the total population with ESRD and with the AGT genotype when patients with glomerulonephritis are considered. Thus, genes of the renin-angiotensin-aldosterone system are candidate genes for further understanding of the interindividual differences in the development and course of ESRD.

The role of the 11beta-hydroxysteroid dehydrogenase type 2 in human hypertension

The 11 beta-hydroxysteroid dehydrogenase type 2 (11 PHSD2) enzyme inactivates 11 betahydroxy steroids in sodium-transporting epithelia such as the kidney, thus protecting the non-selective mineralocorticoid receptor (MR) from occupation by cortisol in humans. Inhibition by xenobiotics such as liquorice or mutations in the HSD11 B2 gene, as occur in the rare monogenic hypertensive syndrome of apparent mineralocorticoid excess (AME), result in a compromised 11 betaHSD2 enzyme activity, which in turn leads to overstimulation of the MR by cortisol, sodium retention, hypokalaemia, low plasma renin and aldosterone concentrations, and hypertension. Whereas the first patients described with AME had a severe form of hypertension and metabolic derangements, with an increased urinary ratio of cortisol (THF+5alphaTHF) to cortisone (THE) metabolites, more subtle effects of mild 11 beta HSD2 deficiency on blood pressure have recently been observed. Hypertension with no other characteristic signs of AME was found in the heterozygous father of a child with AME, and we described a girl with a homozygous gene mutation resulting in only a slightly reduced 11 beta HSD2 activity causing 'essential' hypertension. Thus, depending on the degree of loss of enzyme activity, 11 beta HSD2 mutations can cause a spectrum of phenotypes ranging from severe, life-threatening hypertension in infancy to a milder form of the disease in adults. Patients with essential hypertension usually do not have overt signs of mineralocorticoid excess, but nevertheless show a positive correlation between blood pressure and serum sodium levels, or a negative correlation with potassium concentrations, suggesting a mineralocorticoid influence. Recent studies revealed a prolonged half-life of cortisol and an increased ratio of urinary cortisol to cortisone metabolites in some patients with essential hypertension. These abnormalities may be genetically determined. A genetic association of a HSD11 B2 flanking microsatellite and hypertension in black patients with end-stage renal disease has been reported. A recent analysis of a CA-repeat allele polymorphism in unselected patients with essential hypertension did not find a correlation between this marker and blood pressure. Since steroid hormones with mineralocorticoid action modulate renal sodium retention, one might hypothesize that genetic impairment of 11 beta HSD2 activity would be more prevalent in salt-sensitive as compared with salt-resistant subjects. Accordingly, we found a significant association between the polymorphic CA-microsatellite marker and salt-sensitivity. Moreover, the mean ratio of urinary cortisol to cortisone metabolites, as a measure for 11betaHSD2 activity, was markedly elevated in salt-sensitive subjects. These findings suggest that variants of the HSD11 B2 gene may contribute to the enhanced blood pressure response to salt in some humans.

Molecular basis of human salt sensitivity: the role of the 11beta-hydroxysteroid dehydrogenase type 2

Salt-sensitive subjects (SS) increase their blood pressure with increasing salt intake. Because steroid hormones modulate renal sodium retention, we hypothesize that the activity of the 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2) enzyme is impaired in SS subjects as compared with salt-resistant (SR) subjects. The 11betaHSD2 enzyme inactivates 11-hydroxy steroids in the kidney, thus protecting the nonselective mineralocorticoid receptor from occupation by glucocorticoids. We performed an association study using a recently identified single AluI polymorphism in exon 3 and a polymorphic microsatellite marker of the HSD11B2 gene in 149 normotensive white males (37 SS and 112 SR). The activity of the enzyme 11betaHSD2 was assessed by determining the urinary ratio of cortisol (THF+5alphaTHF) to cortisone (THE) metabolites by gas chromatography in all the 37 SS subjects and in 37 age- and body habitus-matched SR volunteers. Mean (THF+5alphaTHF)/THE ratio was markedly elevated in SS subjects compared with SR subjects (1.51 +/- 0.34 vs. 1.08 +/- 0.26, P < 0.00001), indicating enhanced access of glucocorticoids to the mineralocorticoid receptor in SS subjects. In 58% of SS subjects this ratio was higher than the maximum levels in SR subjects. The salt-induced elevation in arterial pressure increased with increasing (THF+5alphaTHF)/THE ratio (r2 = 0.51, P < 0.0001). A total of 12 alleles of the polymorphic microsatellite marker were detected. Homozygosity for the allele A7 was higher in SS subjects than in SR subjects (41 vs. 28%, P < 0.005), whereas the occurrence of the allele A7 with allele A8 was lower in SS subjects than in SR subjects (8 vs. 15%, P < 0.03). The prevalence of salt sensitivity was 35% in subjects with allele A7/A7, whereas salt sensitivity was present in only 9% of the subjects with allele A7/A8. The (THF+5alphaTHF)/THE ratio was higher in subjects homozygous for the A7 microsatellite allele as compared with the corresponding control subjects. The prevalence of the AluI allele was 8.0% in SR subjects and 5.4% in SS subjects and did not correlate with blood pressure. The decreased activity of the 11betaHSD2 in SS subjects indicates that this enzyme is involved in salt-sensitive blood pressure response in humans. The association of a polymorphic microsatellite marker of the gene with a reduced 11betaHSD2 activity suggests that variants of the HSD 11B2 gene contribute to enhanced blood pressure response to salt in humans.

Serum glucagon concentration and hyperinsulinaemia influence renal haemodynamics and urinary protein loss in normotensive patients with central obesity

OBJECTIVES

Insulin-resistance syndrome and hyperinsulinaemia are linked with cardiovascular disease (CVD) in the obese population. In particular, cardiovascular risk is more frequent in central obesity and is associated with microalbuminuria (MA). MA and changes of glomerular permeability to proteins in obesity might be related with renal haemodynamic modifications (that is glomerular hyperfiltration). Since glucagon is physiologically involved in renal haemodynamic regulation, the purpose of this study was to examine whether changes of circulating glucagon levels might haemodynamically induce MA and proteinuria in patients with central obesity.

SUBJECTS

Forty normotensive obese out-patients, 22 with central (CO group) and 18 with peripheral (PO group) body fat distribution and 11 healthy subjects.

MEASUREMENTS

Serum insulin and glucagon concentrations (fasting and after oral glucose tolerance test (OGTT)) by radio immuno assay (RIA); glomerular filtration rate (GFR, isotopic); total clearances and urinary excretion rates of albumin (AER), IgG (IgGER) and alpha1 microglobulin (computerized immunonephelometry).

RESULTS

GFR and insulin concentrations (fasting and during OGTT) were higher in the CO than the PO group. Fasting glucagon concentrations were increased, and not physiologically suppressed during OGTT in patients with CO (fasting, P<0.05; OGTT 60 and 120 min, P<0.001 vs PO group). Moreover, glucagon concentrations were significantly correlated with GFR in the CO group (fasting, r=0.49, P<0.05; 60 min after OGTT, r=0.58, P<0.01); whereas no correlations were found in the PO group. Higher AER (P<0.001), IgGER (P<0.001) and alpha1 microglobulin (P<0.05) urinary concentrations were found in patients with CO than in the PO group.

CONCLUSIONS

The increase of serum glucagon concentrations may be associated with the enhancement of GFR in patients with central obesity. Glomerular hyperfiltration might influence the development of MA and of proteinuria by means of a haemodynamic mechanism so contributing to increase the risk of renal microvascular complications and of CVD in central obesity.

Regulation of ionotropic glutamate receptors in the rat brain in response to the atypical antipsychotic seroquel (quetiapine fumarate)

The interplay between dopamine and glutamate appears to be relevant in the etiopathology of schizophrenia. Although currently used antipsychotics do not interact with glutamatergic receptors, previous results have demonstrated that the expression profile of ionotropic glutamate receptors can be regulated by drugs such as haloperidol or clozapine. In the present investigation, the mRNA levels for NMDA and AMPA receptor subunits were measured after chronic treatment with the novel antipsychotic agent Seroquel (quetiapine fumarate, quetiapine) as compared to haloperidol and clozapine. Similarly to the prototype atypical clozapine, quetiapine reduced the mRNA expression for NR-1 and NR-2C, two NMDA forming subunits, in the nucleus accumbens. Furthermore, quetiapine, but not haloperidol or clozapine, increased the hippocampal expression for the AMPA subunits GluR-B and GluR-C. The differences between classical and atypical antipsychotics, as well as among the novel agents, might be relevant for specific aspects of their therapeutic activity and could provide valuable information for the role of glutamate in specific symptoms of schizophrenia.

Cortisol increases transfection efficiency of cells

DNA uptake can be facilitated by addition of physiological amounts of 11beta-hydroxy glucocorticosteroids (such as cortisol) during transfection. In the presence of cortisol, but not of the inactive 11-keto glucocorticoid cortisone, twice as many cells uptake and express the reporter gene. The effect is specific and dose-dependent; the amounts of glucocorticosteroids needed to enhance transfection efficiency are in the nanomolar range, which corresponds to the dissociation constant of glucocorticoids for the glucocorticoid receptor in vitro. This effect can be abolished by an excess of the glucocorticoid antagonist RU486. We infer that the activated cytoplasmic glucocorticoid receptors enhance nuclear translocation of the incoming transfected DNA.

Regulation of NMDA receptor subunit messenger RNA levels in the rat brain following acute and chronic exposure to antipsychotic drugs

Based on anatomical and biochemical observations a role of glutamate in schizophrenia has been postulated. In the present work we have investigated the gene expression for two families of NMDA receptor subunits (NR-1 and NR-2) following acute and chronic treatment with typical (haloperidol) and atypical (clozapine) antipsychotic drug (APD) in rats. A single injection of the two drugs elicited a significant increase in the mRNA levels of NR-2B in the nucleus accumbens, whereas only haloperidol was able to elevate NR-2A and NR-2B in the hippocampus. Following a 21 day treatment, significant differences in the regulatory pattern of NMDA-R subunits were observed. Haloperidol increased their mRNA levels in striatum whereas clozapine, consistent with its relatively weaker influence on nigro-striatal dopamine function, did not change the expression of NR subunits in this region. Both APD's were able to decrease the expression of NR-2 subunits in the hypothalamus, but only clozapine was capable of reducing NR-2C in frontal cortex and accumbens. The regulation of NMDA-R subunits in specific brain regions may represent a novel and important mechanism through which APD's exert some of their effects on brain function.

Cyclic AMP-dependent regulation of fibroblast growth factor-2 messenger RNA levels in rat cortical astrocytes: comparison with fibroblast growth factor-1 and ciliary neurotrophic factor

The present study was undertaken to investigate the regulatory mechanisms of fibroblast growth factor-1 and -2 (FGF-1 and FGF-2) gene expression compared with ciliary neurotropic factor (CNTF) in rat cortical astrocytes. Glial cells represent a source of different trophic factors and cytokines that can influence the survival of multiple cell populations within the central nervous system. We found that the beta-adrenergic receptor agonist (betaAR) isoproterenol produced a significant induction of FGF-2 gene expression and protein in type I astrocytes. On the contrary, the gene expression for FGF-1 and CNTF is markedly reduced after exposure to isoproterenol. The changes produced by the beta AR agonist is mimicked by cyclic AMP analogues (8-bromo-cAMP) or 3-isobutyl-1-methyl-xanthine, a cAMP phosphodiesterase inhibitor, which indicates that intracellular elevation of this second messenger is responsible for these effects. The regulation of neurotrophic factors by isoproterenol is not restricted to cortical astrocytes and may take place through different mechanisms. Inhibition of protein synthesis prevents the decrease in CNTF without affecting the changes in FGF-1 and FGF-2 gene expression. Coincubation of isoproterenol with actinomycin D, an inhibitor of gene transcription, prevents the modification of neurotrophic factor biosynthesis, indicating that transcriptional mechanisms are indeed involved in these regulatory pathways. However, the determination of FGF-2 mRNA half-life suggests that the effect of the betaAR agonist can be in part the result of mRNA stabilization. The mechanisms that we describe can be important in the maintenance of neuronal homeostasis and may be relevant in the development of alternative strategies for the treatment of acute and chronic neurodegenerative disorders