Towards Uncovering the Role of Incomplete Penetrance in Maculopathies through Sequencing of 105 Disease-Associated Genes

Inherited macular dystrophies (iMDs) are a group of genetic disorders, which affect the central region of the retina. To investigate the genetic basis of iMDs, we used single-molecule Molecular Inversion Probes to sequence 105 maculopathy-associated genes in 1352 patients diagnosed with iMDs. Within this cohort, 39.8% of patients were considered genetically explained by 460 different variants in 49 distinct genes of which 73 were novel variants, with some affecting splicing. The top five most frequent causative genes were ABCA4 (37.2%), PRPH2 (6.7%), CDHR1 (6.1%), PROM1 (4.3%) and RP1L1 (3.1%). Interestingly, variants with incomplete penetrance were revealed in almost one-third of patients considered solved (28.1%), and therefore, a proportion of patients may not be explained solely by the variants reported. This includes eight previously reported variants with incomplete penetrance in addition to CDHR1:c.783G>A and CNGB3:c.1208G>A. Notably, segregation analysis was not routinely performed for variant phasing-a limitation, which may also impact the overall diagnostic yield. The relatively high proportion of probands without any putative causal variant (60.2%) highlights the need to explore variants with incomplete penetrance, the potential modifiers of disease and the genetic overlap between iMDs and age-related macular degeneration. Our results provide valuable insights into the genetic landscape of iMDs and warrant future exploration to determine the involvement of other maculopathy genes.

SRSF1 haploinsufficiency is responsible for a syndromic developmental disorder associated with intellectual disability

SRSF1 (also known as ASF/SF2) is a non-small nuclear ribonucleoprotein (non-snRNP) that belongs to the arginine/serine (R/S) domain family. It recognizes and binds to mRNA, regulating both constitutive and alternative splicing. The complete loss of this proto-oncogene in mice is embryonically lethal. Through international data sharing, we identified 17 individuals (10 females and 7 males) with a neurodevelopmental disorder (NDD) with heterozygous germline SRSF1 variants, mostly de novo, including three frameshift variants, three nonsense variants, seven missense variants, and two microdeletions within region 17q22 encompassing SRSF1. Only in one family, the de novo origin could not be established. All individuals featured a recurrent phenotype including developmental delay and intellectual disability (DD/ID), hypotonia, neurobehavioral problems, with variable skeletal (66.7%) and cardiac (46%) anomalies. To investigate the functional consequences of SRSF1 variants, we performed in silico structural modeling, developed an in vivo splicing assay in Drosophila, and carried out episignature analysis in blood-derived DNA from affected individuals. We found that all loss-of-function and 5 out of 7 missense variants were pathogenic, leading to a loss of SRSF1 splicing activity in Drosophila, correlating with a detectable and specific DNA methylation episignature. In addition, our orthogonal in silico, in vivo, and epigenetics analyses enabled the separation of clearly pathogenic missense variants from those with uncertain significance. Overall, these results indicated that haploinsufficiency of SRSF1 is responsible for a syndromic NDD with ID due to a partial loss of SRSF1-mediated splicing activity.

Combining computed tomography and biologically effective dose in radiomics and deep learning improves prediction of tumor response to robotic lung stereotactic body radiation therapy

PURPOSE

The aim of this study is to improve the performance of machine learning (ML) models in predicting response of non-small cell lung cancer (NSCLC) to stereotactic body radiation therapy (SBRT) by integrating image features from pre-treatment computed tomography (CT) with features from the biologically effective dose (BED) distribution.

MATERIALS AND METHODS

Image features, consisting of crafted radiomic features or machine-learned features extracted using a convolutional neural network, were calculated from pre-treatment CT data and from dose distributions converted into BED for 80 NSCLC lesions over 76 patients treated with robotic guided SBRT. ML models using different combinations of features were trained to predict complete or partial response according to response criteria in solid tumors, including radiomics CT (Rad_CT ), radiomics CT and BED (Rad_CT,BED ), deep learning (DL) CT (DL_CT ), and DL CT and BED (DL_CT,BED ). Training of ML included feature selection by neighborhood component analysis followed by ensemble ML using robust boosting. A model was considered as acceptable when the sum of average sensitivity and specificity on test data in repeated cross validations was at least 1.5.

RESULTS

Complete or partial response occurred in 58 out of 80 lesions. The best models to predict the tumor response were those using BED variables, achieving significantly better area under curve (AUC) and accuracy than those using only features from CT, including a Rad_CT,BED model using three radiomic features from BED, which scored an accuracy of 0.799 (95% confidence intervals (0.75-0.85)) and AUC of 0.773 (0.688-0.846), and a DL_CT,BED model also using three variables with an accuracy of 0.798 (0.649-0.829) and AUC of 0.812 (0.755-0.867).

CONCLUSION

According to our results, the inclusion of BED features improves the response prediction of ML models for lung cancer patients undergoing SBRT, regardless of the use of radiomic or DL features.

Inherited Retinal Diseases Due to RPE65 Variants: From Genetic Diagnostic Management to Therapy

Inherited retinal diseases (IRDs) are a heterogeneous group of conditions that include retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) and early-onset severe retinal dystrophy (EO[S]RD), which differ in severity and age of onset. IRDs are caused by mutations in >250 genes. Variants in the RPE65 gene account for 0.6-6% of RP and 3-16% of LCA/EORD cases. Voretigene neparvovec is a gene therapy approved for the treatment of patients with an autosomal recessive retinal dystrophy due to confirmed biallelic RPE65 variants (RPE65-IRDs). Therefore, the accurate molecular diagnosis of RPE65-IRDs is crucial to identify 'actionable' genotypes-i.e., genotypes that may benefit from the treatment-and is an integral part of patient management. To date, hundreds of RPE65 variants have been identified, some of which are classified as pathogenic or likely pathogenic, while the significance of others is yet to be established. In this review, we provide an overview of the genetic diagnostic workup needed to select patients that could be eligible for voretigene neparvovec treatment. Careful clinical characterization of patients by multidisciplinary teams of experts, combined with the availability of next-generation sequencing approaches, can accelerate patients' access to available therapeutic options.

Radiomics and deep learning in lung cancer

Lung malignancies have been extensively characterized through radiomics and deep learning. By providing a three-dimensional characterization of the lesion, models based on radiomic features from computed tomography (CT) and positron-emission tomography (PET) have been developed to detect nodules, distinguish malignant from benign lesions, characterize their histology, stage, and genotype. Deep learning models have been applied to automatically segment organs at risk in lung cancer radiotherapy, stratify patients according to the risk for local and distant recurrence, and identify patients candidate for molecular targeted therapy and immunotherapy. Moreover, radiomics has also been applied successfully to predict side effects such as radiation- and immunotherapy-induced pneumonitis and differentiate lung injury from recurrence. Radiomics could also untap the potential for further use of the cone beam CT acquired for treatment image guidance, four-dimensional CT, and dose-volume data from radiotherapy treatment plans. Radiomics is expected to increasingly affect the clinical practice of treatment of lung tumors, optimizing the end-to-end diagnosis-treatment-follow-up chain. The main goal of this article is to provide an update on the current status of lung cancer radiomics.

Electron Density and Biologically Effective Dose (BED) Radiomics-Based Machine Learning Models to Predict Late Radiation-Induced Subcutaneous Fibrosis

Purpose: to predict the occurrence of late subcutaneous radiation induced fibrosis (RIF) after partial breast irradiation (PBI) for breast carcinoma by using machine learning (ML) models and radiomic features from 3D Biologically Effective Dose (3D-BED) and Relative Electron Density (3D-RED). Methods: 165 patients underwent external PBI following a hypo-fractionation protocol consisting of 40 Gy/10 fractions, 35 Gy/7 fractions, and 28 Gy/4 fractions, for 73, 60, and 32 patients, respectively. Physicians evaluated toxicity at regular intervals by the Common Terminology Adverse Events (CTAE) version 4.0. RIF was assessed every 3 months after the completion of radiation course and scored prospectively. RIF was experienced by 41 (24.8%) patients after average 5 years of follow up. The Hounsfield Units (HU) of the CT-images were converted into relative electron density (3D-RED) and Dose maps into Biologically Effective Dose (3D-BED), respectively. Shape, first-order and textural features of 3D-RED and 3D-BED were calculated in the planning target volume (PTV) and breast. Clinical and demographic variables were also considered (954 features in total). Imbalance of the dataset was addressed by data augmentation using ADASYN technique. A subset of non-redundant features that best predict the data was identified by sequential feature selection. Support Vector Machines (SVM), ensemble machine learning (EML) using various aggregation algorithms and Naive Bayes (NB) classifiers were trained on patient dataset to predict RIF occurrence. Models were assessed using sensitivity and specificity of the ML classifiers and the area under the receiver operator characteristic curve (AUC) of the score functions in repeated 5-fold cross validation on the augmented dataset. Results: The SVM model with seven features was preferred for RIF prediction and scored sensitivity 0.83 (95% CI 0.80-0.86), specificity 0.75 (95% CI 0.71-0.77) and AUC of the score function 0.86 (0.85-0.88) on cross-validation. The selected features included cluster shade and Run Length Non-uniformity of breast 3D-BED, kurtosis and cluster shade from PTV 3D-RED, and 10th percentile of PTV 3D-BED. Conclusion: Textures extracted from 3D-BED and 3D-RED in the breast and PTV can predict late RIF and may help better select patient candidates to exclusive PBI.

Impact assessment of an education course on vaccinations in a population of pregnant women: a pilot study

Introduction

Although the benefits of vaccinations have been extensively demonstrated, vaccination coverage remains unsatisfactory as result of many people’s poor knowledge and negative perception of vaccination.

We evaluated the impact of an education course on vaccinations in a population of pregnant women.

Methods

A total of 214 pregnant women were invited to participate in this project, which was undertaken at the Obstetrics and Gynaecology Department of Careggi University Hospital in Florence (Italy). Anonymous questionnaires were administered to women before and after the intervention.

A descriptive and statistical analysis was carried out in order to compare the responses obtained before and after the intervention.

Results

Adherence to the initiative was good (98%): initially, the respondents were not hostile to vaccinations, though many (43%) were poorly or insufficiently informed. The educational intervention had a positive impact. After the intervention, the number of women who rated their level of knowledge of vaccinations as poor or insufficient had decreased by 30% and the number of “hesitant” respondents had decreased with respect to all aspects of the study, especially the decision to be vaccinated during pregnancy.

Conclusions

Hesitancy stems from a lack of accurate information. Healthcare professionals need to improve their communication skills. Appropriate education during pregnancy, when women are more receptive, may have a highly positive impact. These observations need to be considered in the planning of courses to prepare pregnant women for delivery also in other maternal-foetal centres in Italy.

Prediction of skin dose in low-kV intraoperative radiotherapy using machine learning models trained on results of in vivo dosimetry

PURPOSE

The purpose of this study was to implement a machine learning model to predict skin dose from targeted intraoperative (TARGIT) treatment resulting in timely adoption of strategies to limit excessive skin dose.

METHODS

A total of 283 patients affected by invasive breast carcinoma underwent TARGIT with a prescribed dose of 6 Gy at 1 cm, after lumpectomy. Radiochromic films were used to measure the dose to the skin for each patient. Univariate statistical analysis was performed to identify correlation of physical and patient variables with measured dose. After feature selection of predictors of in vivo skin dose, machine learning models stepwise linear regression (SLR), support vector regression (SVR), ensemble with bagging or boosting, and feed forward neural networks were trained on results of in vivo dosimetry to derive models to predict skin dose. Models were evaluated by tenfold cross validation and ranked according to root mean square error (RMSE) and adjusted correlation coefficient of true vs predicted values (adj-R² ).

RESULTS

The predictors correlated with in vivo dosimetry were the distance of skin from source, depth-dose in water at depth of the applicator in the breast, use of a replacement source, and irradiation time. The best performing model was SVR, which scored RMSE and adj-R² , equal to 0.746 [95% confidence intervals (CI), 95% CI 0.737,0.756] and 0.481 (95% CI 0.468,0.494), respectively, on the tenfold cross validation.

CONCLUSION

The model trained on results of in vivo dosimetry can be used to predict skin dose during setup of patient for TARGIT and this allows for timely adoption of strategies to prevent of excessive skin dose.

Optimizing Craniospinal Radiotherapy Delivery in a Pediatric Patient Affected by Supratentorial PNET: A Case Report

New advances in radiation therapy for children allow increased conformability and reduced doses to non-target tissues. We report our experience in treating a 4-year-old child with craniospinal tomotherapy after surgery of the primary tumor, a supratentorial primitive neuroectodermal tumor. The tomotherapy plan was compared with conventional craniospinal irradiation, 3D conformal radiation therapy, and intensity-modulated radiation therapy plans. The possible disadvantages of tomotherapy related to the radiation dose to organs at risk, treatment planning, and anesthesia should be carefully considered as the use of the technique is not suggested in a general manner, but selectively, in critical pediatric radiotherapy cases.

Voxel-by-voxel correlation between radiologically radiation induced lung injury and dose after image-guided, intensity modulated radiotherapy for lung tumors

PURPOSE

To correlate radiation dose to the risk of severe radiologically-evident radiation-induced lung injury (RRLI) using voxel-by-voxel analysis of the follow-up computed tomography (CT) of patients treated for lung cancer with hypofractionated helical Tomotherapy.

METHODS AND MATERIALS

The follow-up CT scans from 32 lung cancer patients treated with various regimens (5, 8, and 25 fractions) were registered to pre-treatment CT using deformable image registration (DIR). The change in density was calculated for each voxel within the combined lungs minus the planning target volume (PTV). Parameters of a Probit formula were derived by fitting the occurrences of changes of density in voxels greater than 0.361gcm^-3 to the radiation dose. The model's predictive capability was assessed using the area under receiver operating characteristic curve (AUC), the Kolmogorov-Smirnov test for goodness-of-fit, and the permutation test (P_test).

RESULTS

The best-fit parameters for prediction of RRLI 6months post RT were D₅₀ of 73.0 (95% CI 59.2.4-85.3.7)Gy, and m of 0.41 (0.39-0.46) for hypofractionated (5 and 8 fractions) and D₅₀ of 96.8 (76.9-123.9)Gy, and m of 0.36 (0.34-0.39) for 25 fractions RT. According to the goodness-of-fit test the null hypothesis of modeled and observed occurrence of RRLI coming from the same distribution could not be rejected. The AUC was 0.581 (0.575-0.583) for fractionated and 0.579 (0.577-0.581) for hypofractionated patients. The predictive models had AUC>upper 95% band of the P_test.

CONCLUSIONS

The correlation of voxel-by-voxel density increase with dose can be used as a support tool for differential diagnosis of tumor from benign changes in the follow-up of lung IMRT patients.

Interaction of vaginal Lactobacillus strains with HeLa cells plasma membrane

Vaginal lactobacilli offer protection against recurrent urinary and vaginal infections. The precise mechanisms underlying the interaction between lactobacilli and the host epithelium remain poorly understood at the molecular level. Deciphering such events can provide valuable information on the mode of action of commensal and probiotic bacteria in the vaginal environment. We investigated the effects exerted by five Lactobacillus strains of vaginal origin (Lactobacillus crispatus BC1 and BC2, Lactobacillus gasseri BC9 and BC11 and Lactobacillus vaginalis BC15) on the physical properties of the plasma membrane in a cervical cell line (HeLa). The interaction of the vaginal lactobacilli with the cervical cells determined two kinds of effects on plasma membrane: (1) modification of the membrane polar lipid organisation and the physical properties (L. crispatus BC1 and L. gasseri BC9); (2) modification of α5β1 integrin organisation (L. crispatus BC2, L. gasseri BC11 and L. vaginalis BC15). These two mechanisms can be at the basis of the protective role of lactobacilli against Candida albicans adhesion. Upon stimulation with all Lactobacillus strains, we observed a reduction of the basal oxidative stress in HeLa cells that could be related to modifications in physical properties and organisation of the plasma membrane. These results confirm the strictly strain-specific peculiarities of Lactobacillus and deepen the understanding of the mechanisms underlying the health-promoting role of this genus within the vaginal ecosystem.

Image-guided volumetric arc radiotherapy of pancreatic cancer with simultaneous integrated boost: Optimization strategies and dosimetric results

PURPOSE

To introduce volumetric modulated arc therapy treatments (VMAT) with simultaneous integrated boost (SIB) for pancreatic cancer and describe dosimetric results on a large patient series.

METHODS AND MATERIALS

45 patients with pancreatic malignancies were treated with 18 MV single-arc VMAT. Image guidance was performed with daily online kilo-volt cone-beam computed tomography (CBCT). The conformity index (CI) and homogeneity index (HI) to the target volumes, PTV45Gy and PTV54Gy, and dose-volume indices to OARs from the QUANTEC task group were reported. The risk of clinical nephritis was evaluated using normal tissue complication probability (NTCP). Treatments were verified in-phantom with the Delta4 system.

RESULTS

Average CI was 1.06 with 95% confidence intervals (95% CI) of 0.97-1.22 for PTV45Gy and 1.17 (0.66-1.61) for PTV54Gy. HI of PTV54Gy was 1.06 (1.04-1.10). OAR constraints were achieved in all patients, except for kidneys V12Gy of 48 (35.4-72.3)%. NTCP of the kidneys was 0.98 (0.6-1.7)%. Kidneys V12Gy and V20Gy were inversely related to PTV54Gy CI and maximum dose. All in-phantom tests had gamma pass rates exceeding 95% with global 3% dose difference and 3 mm distance to agreement. Patient shifts measured with CBCT had 95% CI of -0.8, +0.8 in the RL, -0.7, +0.8 in the SI, and -0.8, +0.7 cm in the AP directions.

CONCLUSIONS

Dosimetric results of VMAT were excellent on PTVs and organs at risk. The kidneys represent the dose-limiting organ at risk for this technique. NTCP indicates that this technique is safe from radiation-induced side effects to the kidneys.

Fiducial markers for image-guided partial breast irradiation

PURPOSE

This study was undertaken to study the role of fiducial markers for image-guided partial breast irradiation (IG-PBI), and to compare the shifts based on bony anatomy and fiducial markers.

MATERIALS AND METHODS

Fifteen patients underwent IGPBI. Three fiducial markers were placed in the tumour bed at the time of surgery. Daily orthogonal anterior/ posterior and lateral kV-images were taken before each fraction and compared with the digitally-reconstructed radiographs, both using bony landmarks and fiducial markers as reference. The Student's t test was used to detect a meaningful difference of 3 mm in between the two methods.

RESULTS

A total of 105 image-guided radiation therapy (IGRT) sessions were obtained. The mean superior/inferior, right/left, and anterior/posterior shifts obtained using the bony landmarks vs. the fiducial markers were 2 mm [standard deviation (SD) 10 mm] vs. 0 mm (SD 7 mm), 0 mm (SD 7 mm) vs. 1 mm (SD 4 mm), and 1 mm (SD 7 mm) vs. 0 mm (SD 5 mm), respectively. The mean shift differences in absolute value between the two methods, along the superior/inferior, right/left and anterior/posterior directions were 5 mm (p=0.001), 3 mm [p=not significant (ns)], and 3 mm (p=ns), respectively.

CONCLUSIONS

Fiducial markers for IG-PBI increase set-up accuracy compared to the bony landmarks, in particular along the superior/inferior direction.

A Case of Relapsed Medulloblastoma Treated with Intensity-Modulated Radiotherapy and Temozolomide

We report a case of relapsed high-risk non-metastatic medulloblastoma in a 14-year-old boy, which was treated with intensity-modulated radiotherapy (IMRT) and temozolomide (TMZ). At the age of 11, the patient underwent an MRI-confirmed incomplete resection of a fourth-ventricle medulloblastoma, followed by conventional chemotherapy, craniospinal irradiation (55.8 Gy, 1.8 Gy/fraction) and then myeloablative chemotherapy followed by peripheral blood progenitor cell rescue. After 18 months of complete remission following the completion of chemotherapy, MRI showed a 2.5-cm mass in the olfactory notch. The patient underwent IMRT (45 Gy, 1.8 Gy/fraction) with concomitant administration of TMZ (180 mg/m2, 5 days every 21 days), which was well tolerated. After 5 cycles of TMZ, MRI showed complete remission with no evidence of the mass. TMZ was continued for another 5 cycles and then stopped. At 14 months from the completion of IMRT, a new MRI scan showed multiple nodular relapses around the fourth ventricle and the patient is currently treated with oral etoposide.

Comparative single-dose kinetics and effects of four sulfonylureas in healthy volunteers

The single-dose kinetics and effects of tolbutamide (500 mg), chlorpropamide (250 mg), glibenclamide (5 mg) and glipizide (5 mg) were compared in 7 healthy male volunteers by measurements of serum concentrations of the drugs and of plasma insulin and blood glucose. The drugs were administered both on an empty stomach and together with a standardized breakfast. The concentrations of tolbutamide and chlorpropamide were measured by gas chromatography, those of glipizide with high-pressure liquid chromatography, those of glibenclamide and insulin by radioimmunoassay and those of glucose by the hexokinase method. Glipizide and glibenclamide were more potent inducers of insulin release and blood glucose reduction than tolbutamide and chlorpropamide. As the concentrations of the former two drugs were in the range of nmol/l and those of the latter two in the mumol/l range, the findings support the notion that the intrinsic activity of the two second-generation sulfonylureas is at least 1 000 times greater than that of the two first-generation drugs. Glipizide seemed to be a more potent and more rapid insulin releaser than glibenclamide, but this may be secondary to biopharmaceutic differences between the two preparations. The bioavailability of glipizide was apparently greater than that of glibenclamide. Both glibenclamide (t 1/2 = 1.8 h) and glipizide (t 1/2 = 4.3 h) showed much shorter elimination half-lives than tolbutamide (7 h) and chlorpropamide (34 h). It seems probable, however, that these half-lives are not fully informative as to the duration of action of the drugs.

Effects of beta 1-adrenoceptor blockade in the treatment of hypertension during pregnancy in diabetic women

The effects of beta 1-blockade were investigated in 18 hypertensive pregnant diabetic women. The same women served as controls, covering a period just before therapy. The blood pressure was reduced in 14 women (p less than 0.01). The change in blood glucose homeostasis was statistically not different from the control period. Insulin doses were not affected. The fetal heart rate was affected by therapy, causing a decrease in baseline rate (p less than 0.05) and in acceleration amplitude (p less than 0.05). Although the incidence of suspect fetal distress, intrauterine growth retardation and preterm delivery was high, all surviving infants had normal Apgar scores at 5 and 10 min. Perinatal mortality consisted of one stillbirth. Except for respiratory problems, the incidence of neonatal complications was low. All survivors were healthy at follow-up. We found beta 1-blockade to be effective and safe in this group of high-risk pregnancies, and suggest it as an alternative for anti-hypertensive therapy in diabetic pregnancy.

Effect of dietary fibre on blood glucose, plasma immunoreactive insulin, C-peptide and GIP responses in non insulin dependent (type 2) diabetics and controls

A high fibre and a low fibre breakfast meal were given to eight non insulin dependent diabetics ( NIDD ), and eight controls. Blood glucose response was monitored continuously for three hours and characterized using a straight line model. After the high fibre meal the rates of increase and decrease in blood glucose concentration were slower both in diabetics and controls than after the low fibre meal. The delay time, however, i.e. the time from meal intake to the start of glucose increase, hypothetically corresponding to gastric emptying time, was the same after both test meals. The postprandial glucose increment calculated as the area under the 0-120 min curve was lower after the high fibre meal in the NIDD , but not in the controls. The two-hour C-peptide and gastric inhibitory polypeptide values were lower for the diabetics after the high fibre breakfast. The results indicate a prolonged carbohydrate digestion and/or absorption after high fibre breakfast.

Plasma high density lipoproteins and lipolytic enzyme activities in diabetic patients

Eighty diabetic patients, consecutively selected from an out-patient clinic, were studied with regard to plasma lipoprotein levels, especially HDL. Patients treated with sulphonylureas had 24% lower HDL cholesterol concentrations (p less than 0.01) but only about 7% lower apo AI levels (n.s.) than those on insulin treatment. This difference could at least partly be explained by differences in age and type of diabetes. There was no relationship between the degree of diabetic control, as measured by fasting blood glucose levels, and HDL levels. In two subgroups of insulin-treated diabetics, selected to represent extremely low and high HDL levels (range 0.5-0.8 and 1.8-2.0 mmol/l, respectively) but matched with regard to age, duration of diabetes, insulin dosage and diabetic control, the activities of lipoprotein lipase and hepatic lipase in postheparin plasma were also recorded. The high HDL group had significantly higher lipoprotein lipase activities (p less than 0.01) and significantly lower hepatic lipase activities (p less than 0.05) than the low HDL group, supporting the hypothetical roles of these enzymes in HDL metabolism, and offering a tentative mechanism behind the large variability of HDL levels in diabetics.

Dietary supplementation of fibre (Lunelax) as a mean to reduce postprandial glucose in diabetics

The postprandial glucose concentrations after a standardized breakfast of 12 type II diabetics were followed and the effect of supplementation of a fibre-containing bulk-purgative (Lunelax) to the meal was investigated. It was found that addition of Lunelax reduced the mean increment glucose concentration with about 9%. The patients reported that Lunelax was convenient to take.

Dietary fibre in type II diabetes

Recent studies have indicated that diets rich in digestible carbohydrates and dietary fibre might be beneficial in the regulation of type II non insulin dependent diabetes (NIDD). Addition of the gel forming type of dietary fibre such as pectin and guar gum to meals or glucose solutions reduces post-prandial glucose and insulin response. Addition of cereal fibres in the form of bran seems to have long term beneficial effect improving glucose tolerance. Little is known, however, concerning effects of dietary fibre naturally occurring in food on postprandial glucose and hormone response. In the present study we prepared two breakfast meals which were similar regarding digestible carbohydrates but differed in their dietary fibre content. One of the meals, including whole grain bread and whole apples, contained 8.4 g of dietary fibre, and the other one, containing white bread and apple juice, 3.1 g. When given to eight NIDD, the fibre rich breakfast gave significantly lower blood glucose increment during the three hours following ingestion. The results indicate that foods rich in dietary fibre might be useful in the regulation of type II diabetes.

Thujone—Cause of absinthism?

Habitual abuse of the wormwood spirit absinthe was described in the 19th and 20th centuries as a cause for the mental disorder "absinthism" including the symptoms hallucinations, sleeplessness and convulsions. A controversial discussion is going on if thujone, a characteristic component of the essential oil of the wormwood plant Artemisia absinthium L., is responsible for absinthism, or if it was merely caused by chronic alcohol intoxication or by other reasons such as food adulterations. To ascertain if thujone may have caused absinthism, absinthes were produced according to historic recipes of the 19th century. Commercial wormwood herbs of two different manufacturers, as well as self-cultivated ones, were used in a concentration of 6 kg/100 l spirit. In addition, an authentic vintage Pernod absinthe from Tarragona (1930), and two absinthes from traditional small distilleries of the Swiss Val-de-Travers were evaluated. A GC-MS procedure was applied for the analysis of alpha- and beta-thujone with cyclodecanone as internal standard. The method was shown to be sensitive with a LOD of 0.08 mg/l. The precision was between 1.6 and 2.3%, linearity was obtained from 0.1 to 40 mg/l (r = 1.000). After the recent annulment of the absinthe prohibition all analysed products showed a thujone concentration below the maximum limit of 35 mg/l, including the absinthes produced according to historic recipes, which did not contain any detectable or only relatively low concentrations of thujone (mean: 1.3 +/- 1.6 mg/l, range: 0-4.3 mg/l). Interestingly, the vintage absinthe also showed a relatively low thujone concentration of 1.8 mg/l. The Val-de-Travers absinthes contained 9.4 and 1.7 mg/l of thujone. In conclusion, thujone concentrations as high as 260 mg/l, reported in the 19th century, cannot be confirmed by our study. With regard to their thujone concentrations, the hallucinogenic potential of vintage absinthes can be assessed being rather low because the historic products also comply with today's maximum limits derived to exclude such effects. It may be deduced that thujone plays none, or only a minor role in the clinical picture of absinthism.

Intraoperative radiation therapy for retroperitoneal soft tissue sarcomas

Treatment of retroperitoneal soft tissue sarcomas is a difficult clinical problem. Despite the improvement in resection rates in the most recent surgical series, local control still remains the main problem because of the high incidence of local recurrences after surgery. Postoperative radiation therapy has not been always successful because of dose-tolerance of surrounding normal structures, which prevent the delivery of adequate doses of radiation. To overcome this limitations, new therapeutic approaches including external-beam radiation and intraoperative radiation therapy (IORT) have been evaluated at some Institutions. The results of IORT with or without external-beam radiation are reviewed and our experience with preoperative radiation and IORT is reported. As treatment of retroperitoneal sarcomas has evolved into combined modalities including preoperative radiation, maximum surgical resection and IORT, a possible improvement in local control rates has been achieved. However, locoregional failures and the incidence of distant metastases remain a challenge, emphasising the need for further improvement in local and distant treatment. The new phase II trial, activated within the Italian Sarcoma Group, with preoperative concurrent chemo-radiation therapy and IORT is presented.

Radiotherapy for patients with early-stage glottic carcinoma: univariate and multivariate analyses in a group of consecutive, unselected patients

BACKGROUND

Radiotherapy (RT) has a remarkable success rate in the treatment of patients with glottic carcinoma. The objectives of the current study were to assess the results in a group of consecutive patients with comparable characteristics who were treated with RT (6-megavolt photon linear accelerator) and to determine the prognostic factors that may influence local control in patients with early-stage glottic carcinoma. The impact on local control of tobacco smoking and second primary malignancies also was investigated.

METHODS

Four hundred ten patients with T1-T2 squamous cell carcinoma of the glottis who were treated between 1986 and 2001 were analyzed retrospectively with regard to local control and overall survival. Potential prognostic factors for local control were evaluated with univariate and multivariate models. The impact of technologic advances also was evaluated.

RESULTS

The 5-year and 10-year overall survival rates were 83% and 63.5%, respectively. The overall 10-year local control rate for patients with T1-T2 glottic carcinoma was 89%. The median time to recurrence was 7 months. Univariate analysis showed that tumor category, tumor size, macroscopic appearance of the lesion, RT fraction size, persistent edema, year of RT treatment, unchanged dysphonia, and surgical option all had a significant influence on local control; whereas multivariate analysis showed that only persistent dysphonia and year of RT treatment were significantly associated with increased local control. A 22.2% rate of second primary malignancies was reported: second primary tumors were the major cause of death in the patients studied. Only 2 patients died of laryngeal carcinoma; 304 patients were alive with their disease in complete remission, 1 patient was alive with recurrent laryngeal carcinoma after undergoing salvage surgery, and 103 patients died of either intercurrent disease or a second primary tumor.

CONCLUSIONS

The use of a 6-megavolt photon linear accelerator achieved a high rate of local control in patients with T1-T2 glottic carcinoma. Dysphonia and the year of RT treatment were the most important prognostically significant factors for patient outcome. The occurrence of a second primary tumor was the most frequent cause of death, especially among patients who did not stop smoking after a diagnosis of glottic carcinoma.

Nasopharyngeal cancer WHO type II-III: monoinstitutional retrospective analysis with standard and accelerated hyperfractionated radiation therapy

The aim of this study is to assess the impact of prognostic factors in patients with locoregionally advanced nasopharyngeal cancer (NPC), WHO type II-III, treated with two different radiation therapy (RT) schedules: standard radiation therapy (SRT), and accelerated hyperfractionated radiation therapy (HART), with or without sequential chemotherapy. Between January 1986 and December 1999, 78 consecutive NPC patients were treated either with SRT (until August 1993) or with HART (from September 1993). Of the 78 patients, 60 were males and 18 females, the median age was 56 years (range 14-83). Nine patients had a non-keratinizing carcinoma (WHO type II) and 69 an undifferentiated carcinoma (WHO type III). Five-year overall survival rate (OS) was 62%. Two months after RT, 73 patients were in complete remission. Disease-free survival (DFS) rates at 5 years were: 85% for the HART and 59% for the SRT group, respectively. A multivariate analysis, age (hazard ratio, HR=4.17 for > or = 60 vs. <50 years) and N-stage (HR=3.56 for N3a-N3b vs. N0-N1) were significant for survival, whereas N-stage (HR=8.23 for N3a-N3b vs. N0-N1) and RT schedule (HR=0.30 for HART vs. SRT) were significant for DFS. In our experience, HART achieved higher DFS rates than SRT; however, HART did not favourably affect OS. Toxicity was comparable in the two RT schedules.

Long-term glycaemic improvement after addition of metformin to insulin in insulin-treated obese type 2 diabetes patients

AIM

To assess the adjunct effect of metformin to insulin in type 2 diabetes.

METHODS

Obese and overweight type 2 diabetes patients treated with insulin for at least 1 year, and with poor glycaemic control (HbA1c > upper reference level + 2%), were included in a randomised, double-blind, placebo-controlled study. Patients were treated for 12 months with either metformin (850 mg b.i.d.) or placebo added to their usual insulin, which was stabilized during a 3-month placebo run-in period, but thereafter attempted to be unchanged.

RESULTS

Thirty-seven patients were included. Two patients dropped out during run-in. There were no differences between the metformin (n = 16) and placebo (n = 19) group at baseline. Most patients received multiple insulin injections. Metabolic control was improved by addition of metformin. Mean change in HbA1c from baseline showed highly significant difference between groups at 3, 6, 9 and 12 months. Mean change (percentage units +/- s.d.) at 12 months was -1.1 +/- 0.7% vs. + 0.3 +/- 0.8% (p < 0.001) for HbA1c and -1.4 +/- 2.1 mmol/l vs. + 0.6 +/- 2.2 mmol/l (p = 0.025) for fasting blood glucose. Mean low density lipoprotein (LDL) cholesterol change differed slightly at 6 months, but not at 12 months. There were no changes in insulin dose, blood pressure, body weight, triglycerides, total- and high density lipoprotein (HDL) cholesterol, fibrinogen, C-peptide and laboratory safety variables, including serum B12. Combination therapy was well-tolerated with the same adverse event rate as insulin alone, but more patients with diarrhoea.

CONCLUSION

Addition of metformin to insulin induced and maintained clinically significant and consistent long-term reduction of hyperglycaemia in obese, insulin-treated type 2 diabetes patients.

Determining the binding capability of the mouse major urinary proteins using 2-naphthol as a fluorescent probe

The mouse major urinary proteins (MUPs) are an ensemble of isoforms secreted by adult male mice and involved in sexual olfactory communication. MUPs belong to the lipocalin superfamily, whose conserved structure is a beta-barrel made of eight antiparallel beta-strands forming a hydrophobic pocket that accommodates small organic molecules. A detailed knowledge of the molecular mechanism associated to the binding of those molecules can guide protein engineering to devise mutated proteins where the ligand specificity, binding affinity, and release rate can be modulated. Proteins with such peculiar properties may have interesting biotechnological applications for pest control, as well as in food and cosmetic industries. In this work, we demonstrate that the fluorescent molecule 2-naphthol binds to the natural ligand's binding site of MUPs with high affinity. In addition, we show that 2-naphthol binds to MUPs in its protonated form, that its fluorescence is blue-shifted, and the quantum yield is increased, thus confirming the high hydrophobicity of the protein pocket and the absence of proton acceptors inside the binding site. At large the results presented, besides demonstrating that the use of 2-naphthol provides a convenient and quick method for testing MUPs binding activity and to ascertain the quality of the protein preparation, suggest that MUPs can represent an interesting system for studying the photophysical characteristics of fluorescent molecules in a highly hydrophobic environment.

Trypanosoma cruzi: conformational preferences of antigenic peptides bearing the immunodominant epitope of the B13 antigen

The Trypanosoma cruzi recombinant protein B13 contains tandemly repeated domains and shows high sensitivity in the serological diagnosis of Chagas' disease. It has been shown that the immunodominant epitope of B13 is contained in the GDKPSLFGQAAAGDKPSLF-NH(2) sequence and that the hexapeptide AAAGDK seems to be the "core" of that epitope. Three peptides containing that "core" sequence, one corresponding to the entire repeat motif GDKPSLFGQAAAGDKPSLF-NH(2), pB13, and two smaller fragments, FGQAAAGDK-NH(2), S4, and QAAAGDKPS-NH(2), S5, have been tested in competitive ELISA with recombinant protein B13 in the solid phase against 40 chagasic sera from Brazilian patients. The median percentage inhibition for pB13, S4, and S5 were, respectively, 91, 86, and 68%. The possibility that the distinct antigenic activity of those peptides correlates with the existence of preferential conformational properties has been investigated by CD and NMR spectroscopy. Results indicate their propensity to adopt a helical configuration, centered in the AAAGDK sequence, and whose extent and stability directly correlates with the peptides' antigenicity. The data are discussed in the light of the existence of conformational preferences involving immunodominant epitopes in tandemly repeated antigens.