Cannabidiol ameliorates mitochondrial disease via PPARγ activation in preclinical models

Mutations in mitochondrial energy-producing genes lead to a heterogeneous group of untreatable disorders known as primary mitochondrial diseases (MD). Leigh syndrome (LS) is the most common pediatric MD and is characterized by progressive neuromuscular affectation and premature death. Here, we show that daily cannabidiol (CBD) administration significantly extends lifespan and ameliorates pathology in two LS mouse models, and improves cellular function in fibroblasts from LS patients. CBD delays motor decline and neurodegenerative signs, improves social deficits and breathing abnormalities, decreases thermally induced seizures, and improves neuropathology in affected brain regions. Mechanistically, we identify peroxisome proliferator-activated receptor gamma (PPARγ) as a key nuclear receptor mediating CBD's beneficial effects, while also providing proof of dysregulated PPARγ expression and activity as a common feature in both mouse neurons and fibroblasts from LS patients. Taken together, our results provide the first evidence for CBD as a potential treatment for LS.

Imbalanced mitochondrial dynamics contributes to the pathogenesis of X-linked adrenoleukodystrophy

The peroxisomal disease adrenoleukodystrophy (X-ALD) is caused by loss of the transporter of very-long-chain fatty acids (VLCFAs), ABCD1. An excess of VLCFAs disrupts essential homeostatic functions crucial for axonal maintenance, including redox metabolism, glycolysis and mitochondrial respiration. As mitochondrial function and morphology are intertwined, we set out to investigate the role of mitochondrial dynamics in X-ALD models. Using quantitative 3D transmission electron microscopy, we revealed mitochondrial fragmentation in corticospinal axons in Abcd1- mice. In patient fibroblasts, an excess of VLCFAs triggers mitochondrial fragmentation through the redox-dependent phosphorylation of DRP1 (DRP1S616). The blockade of DRP1-driven fission by the peptide P110 effectively preserved mitochondrial morphology. Furthermore, mRNA inhibition of DRP1 not only prevented mitochondrial fragmentation but also protected axonal health in a Caenorhabditis elegans model of X-ALD, underscoring DRP1 as a potential therapeutic target. Elevated levels of circulating cell-free mtDNA in patients' CSF align this leukodystrophy with primary mitochondrial disorders. Our findings underscore the intricate interplay between peroxisomal dysfunction, mitochondrial dynamics and axonal integrity in X-ALD, shedding light on potential avenues for therapeutic intervention.

Canonical and uncanonical pathogenic germline variants in colorectal cancer patients by next-generation sequencing in a European referral center

BACKGROUND

Despite increasing use of next-generation sequencing (NGS), data concerning the gain in germline pathogenic variants (PVs) remain scanty, especially with respect to uncanonical ones. We aimed to verify the impact of different cancer predisposition genes (CPGs) on colorectal cancer (CRC) in patients referred for genetic evaluation.

MATERIALS AND METHODS

We enrolled for NGS, by Illumina TruSight Cancer panel comprising 94 CPGs, 190 consecutive subjects referred for microsatellite instability (MSI) CRC, polyposis, and/or family history.

RESULTS

Overall, 51 (26.8%) subjects carried 64 PVs; PVs coexisted in 4 (7.8%) carriers. PVs in mismatch repair (MMR) genes accounted for one-third of variant burden (31.3%). Four Lynch syndrome patients (20%) harbored additional PVs (HOXB13, CHEK2, BRCA1, NF1 plus BRIP1); such multiple PVs occurred only in subjects with PVs in mismatch syndrome genes (4/20 versus 0/31; P = 0.02). Five of 22 (22.7%) patients with MSI cancers but wild-type MMR genes harbored PVs in unconventional genes (FANCL, FANCA, ATM, PTCH1, BAP1). In 10/63 patients (15.9%) with microsatellite stable CRC, 6 had MUTYH PVs (2 being homozygous) and 4 exhibited uncanonical PVs (BRCA2, BRIP1, MC1R, ATM). In polyposis, we detected PVs in 13 (25.5%) cases: 5 (9.8%) in APC, 6 (11.8%) with biallelic PVs in MUTYH, and 2 (3.9%) in uncanonical genes (FANCM, XPC). In subjects tested for family history only, we detected two carriers (18.2%) with PVs (ATM, MUTYH).

CONCLUSION

Uncanonical variants may account for up to one-third of PVs, underlining the urgent need of consensus on clinical advice for incidental findings in cancer-predisposing genes not related to patient phenotype.

In vitro characterization and clinical evaluation of skin hydration by two formulations mimicking the skin's natural components

BACKGROUND

We have developed innovative base formulations that were designed to mimic the skin with respect to its components and galenic structure. Components include water, proteins, lipids, sugars and minerals.

OBJECTIVES

We characterized formulations and their skin penetration using in vitro methods and evaluated their impact on skin hydration in a clinical trial.

METHODS

Scanning electron microscopy (SEM) imaging and X-ray diffraction were used to analyse formulations as well as formulation impact on the stratum corneum (SC) structure. Mass spectrometry imaging (MSI) was used to compare formulation ingredients with SC components and to detect their distribution in the skin. Clinical studies were performed to confirm effects on skin hydration and investigate potential adverse skin effects (irritation and sensitization).

RESULTS

SEM and X-ray diffraction of the formulations showed that lipids were organized in sheets similar to SC lipids. MSI demonstrated similarities between formulation components and skin constituents, as well as a good penetration into the skin. The formulations did not modify the lamellar organization of the SC lipids, but they increased the relative proportion of the crystallized lipids and some of the amorphous lipids. In in vivo studies, a high level of hydration was maintained over 24 h after application with an intense and 'very good hydration'. Both formulations were shown to be non-(photo)sensitizers with excellent tolerance. Sensorial evaluation indicated the formulations were not oily or sticky and maintained the skin's suppleness over time. Formulations had a 'nude skin' touch and created a natural protective film.

CONCLUSIONS

The two formulations were well-tolerated and increased skin hydration in clinical subjects, an effect that could contribute to the alleviation of sensitive skin. The formulations were shown to resemble the lipid organization of the stratum corneum, as well as penetrate the skin without disrupting the lipid lamella organization.

A Methodology for Reconstructing Source Properties of a Conical Piezoelectric Actuator Using Array-Based Methods

We investigated the force produced by a conical piezoelectric (PZT, lead zirconate titanate) transducer actuated by high voltage pulses (HVP) in contact with a steel transfer plate. Using elastic wave propagation theory in a semi-infinite plate, we aimed to quantify the magnitude and estimate the shape of the force-time function via the body waves produced in the transfer plate using the displacement field recorded on an array of 20 absolutely calibrated PZT receivers. We first calibrated the receiver array using glass capillary fracture. We proceeded to use a conical PZT transducer to actively produce a source at the origin, allowing us to study the displacement field produced on the now calibrated PZT receiver array. We studied two types of HVP: An impulsive and step source. The calibrated receiver array was used to estimate the general shape of the force-time functions for each type of HVP. From our hypothesized force-time functions we were able to estimate the peak force produced by the PZT actuator: The impulsive source generated a force of f peak = 2.90 ± 0.42 N and the step source generated f peak = 1.79 ± 0.30 N, respectively, for a peak applied voltage of 273 V. This translates to an applied force of ∼ 0.011 N/V and 0.007 N/V for the impulse and step force-time functions, respectively, which is similar to estimates found in the literature for other conical transducers in contact with metallic transfer media. This measurement was verified directly by independent measurements of the peak force f peak using a dynamic force transducer. We found that our methodology correctly estimated the magnitude of the force but is limited to transducers with incident angles θ < 53 ∘ . Beyond this angle, overestimates of the force were observed due to the lack of body wave energy produced by the source. These results allow us to quantitatively determine the forces produced by active PZT techniques using only the measurement of the displacement field captured on a calibrated conical PZT array. Quantitative understanding of active PZT sources additionally constrains the transfer functions approach, which is commonly used in the non-destructive testing of materials and in other fields, such as rock physics and laboratory seismology.

Prognostic role of immunohistochemical overexpression of the p16 protein in women under the age of 35 and diagnosed with HSIL (CIN2) subjected to "cervix sparing" excision

OBJECTIVE

To evaluate the role of immunohistochemical staining overexpression of p16 protein (p16 IHC) as a prognostic factor of persistence or recurrence of intraepithelial disease after excision procedure in young women diagnosed with HSIL (CIN2).

PATIENTS AND METHODS

62 women with a histological diagnosis of HSIL (CIN2) subjected to "cervix sparing" excisional procedure were included in this retrospective study. All had age less than or equal to 35 years, negative history of immunosuppression, available follow-up, and assessment of the resection margins state. Immunohistochemical staining for the p16 protein was evaluated on reviewed and confirmed HSIL (CIN2) histological specimens with negative resection margins. The post-treatment follow-up, including cytology, colposcopy, and histology, ranged from a minimum of 6 months to a maximum of 60 months. The persistence or recurrence of SIL during the follow-up period was based on histologic referral and defined as "the presence of SIL", "the presence of HSIL" and "progression to HSIL (CIN3)".

RESULTS

31/62 patients were positive for immunostaining (p16 IHC+), and 31/62 were negative (p16 IHC-). Persistence or recurrence after excision occurred more frequently within the p16 IHC+ than in p16 IHC- group, both as SIL (29% p16 IHC- vs. 32.3% p16 IHC+, p = 0.783) and HSIL (6.5% p16 IHC- vs. 12.9% p16 IHC+, p = 0.671). None of the patients in the p16 IHC- group showed progression to CIN3 for the entire observation period, whereas 9.7% of p16 IHC+ women progressed to CIN3 lesion (p = 0.042). The p16 IHC positivity showed a significant association with progression to CIN3 in 5 years of follow-up (p = 0.029) and with the presence of SIL after two years of follow-up (p = 0.031). The differences between the two groups increased after two years post-treatment: the p16 IHC- patients still had SIL only in 3.2% of cases and no longer had HSIL, while the p16 IHC+ women still showed SIL in 19.4% and HSIL in 6.5% of cases. The negative predictive value (NPV) of p16 IHC in predicting SIL's presence after treatment increased with the severity of the lesion (NPV for SIL 70.97%, for HSIL 93.55%, for CIN3 100%).

CONCLUSIONS

The study suggests that young patients with p16 IHC- HSIL (CIN2) have a better post-excisional course of the cervical intraepithelial disease compared to p16 IHC+ women and that p16 IHC could have prognostic utility during the long-term follow-up, especially in forecasting progression to CIN3 in consideration of the high NPV (up to 100%). The efficacy of the adjuvant HPV vaccination in the management of HSIL (CIN2) p16+ young women is to be evaluated as part of the fertility-sparing treatment.

Sensitivity and specificity values of high-risk HPV DNA, p16/ki-67 and HPV mRNA in young women with atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL)

OBJECTIVE

The aim of the study was to evaluate the sensitivity and specificity values of high-risk HPV DNA test, p16/ki-67, and HPV mRNA in histologically high-grade cervical intraepithelial lesions (CIN2-CIN3) in women aged 21-24 years with diagnosis of atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL) at pap smear.

PATIENTS AND METHODS

342 patients between 21-24 years old, attending spontaneously our clinics, 118 with ASCUS and 224 with LSIL, were enrolled in the study. All patients underwent colposcopy and biopsies were performed in the areas with major changes. All patients were tested at the same time for p16/ki-67, high-risk HPV DNA and HPV mRNA.

RESULTS

Nineteen out of 118 women with ASCUS showed a high-grade cervical intraepithelial lesion, 11 out of 118 (9.32%) CIN2, and 8 out of 118 (6.78%) CIN3. The sensitivity of high-risk HPV DNA was 99.9%, and the specificity 23.2%; p16/ki-67 pointed out a sensitivity of 90.9%, and a specificity of 81.8%; HPV mRNA showed a sensitivity of 81.8%, and specificity of 87.9% in CIN2 lesions. In CIN3 lesions, the sensitivity of high-risk HPV DNA was 99.9%, while the specificity was 19.1%; p16/ki-67 showed a sensitivity of 99.9%, and a specificity of 73.7%; HPV mRNA relived a sensitivity of 87.5%, and a specificity of 80.8%. In women with LSIL, a total of 42/224 (18.75%) of CIN2 were found at the histopathological examination, while 17/224 (7.59%) women presented a CIN3. No case of invasive cancer was identified. High-risk HPV DNA was positive in 190/224 (84.8%), p16/ki-67 in 119/224 (53.1%), and HPV mRNA in 104/224 (46.4%). In women with CIN2, the sensitivity of high-risk HPV DNA was of 92.8%, and the specificity 17.5%, the sensitivity of p16/ki-67 was 95.2%, and specificity 61.8%. HPV mRNA showed a sensitivity of 88.8% and a specificity of 87.8%. In women with CIN3, the sensitivity of high-risk HPV DNA was 88.2%, and the specificity 29.7%; p16/ki-67 pointed out a sensitivity of 94.1%, and a specificity of 49%; HPV mRNA showed a sensitivity of 88.2% and a specificity of 80.6.

CONCLUSIONS

Taking into account the high rate of spontaneous regression of high-grade lesions in young women, these tests, in particular, the HPV mRNA test, used as a triage test for ASCUS or LSIL, can modify follow-up triage strategy. In fact, this biomarker, due to its high specificity, could lead to a cytology repetition instead of an immediate colposcopy, avoiding over diagnosis and potential overtreatment in this category of women.

Early extubation following cardiac surgery in adult congenital heart disease improves post-operative haemodynamics and reduces costs

Background

In paediatric cardiac surgery, there has been a paradigm shift in perioperative management from a slow wean of mechanical ventilation in the intensive care unit (ICU), to “ultra fast-track” anaesthesia with early extubation (EE) in theatre to promote a faster recovery. Adults with congenital heart disease (ACHD) have multiple risk factors for prolonged intubation, including a greater proportion of re-do interventions, more co-morbidities and metabolic differences leading to slower emergence from anaesthesia. As a result, EE remains unproven and has not been widely adopted and in this patient group.

Aim

To assess the effects of EE on post-operative haemodynamics, hospital stay and associated healthcare costs.

Methods

Data were collected on ACHD patients, who underwent cardiac surgery in a high-volume tertiary centre between 2012 and 2018. Propensity score matching (1:1 or 2:1 where possible) was performed using the following variables: age, sex, body mass index, CHD complexity, functional class, length of surgery, systemic ventricular function, procedure-specific risk (adult congenital heart score; ACHS), urgent versus elective procedure, active endocarditis, pulmonary hypertension and renal dysfunction.

Results

614 procedures were performed during the study period. After matching, 87 (14.2%) patients receiving EE were compared to 164 patients who received conventional care (CC). The overall complication rate was low, with no difference between the EE and CC groups (8.0% vs. 9.1%, p=0.77), and a very low reintubation rate (&lt;1%). EE patients had a significantly shorter post-operative hospital length of stay in ICU and the high dependency unit (HDU; 48 [43–51] vs. 50 [47–69] hours, p&lt;0.0001). EE patients required less inotropic & vasopressor support, as demonstrated by a lower Vasoactive-Inotropic Score (VIS) compared to patients following NEE (median VIS 0.5 [0.0–1.8] vs. 2.0 [0.0–3.5], p&lt;0.0001). The total fluid balance by the third post-operative day was more positive after CC than EE (1177±737mL vs. 927±780mL, p=0.004). Finally, lower combined ICU and HDU costs were incurred by EE compared with CC (£3.9K[2.8–4.2K] vs. £4.2K[3.9–6.3K], p&lt;0.0001).

Conclusion

In ACHD patients undergoing cardiac surgery, including complex and redo procedures, EE was safe, associated with a shorter ITU and HDU stay and lower hospital costs.

Funding Acknowledgement

Type of funding source: None

Measuring Breathing Patterns in Mice Using Whole-body Plethysmography

Respiratory dysfunction is among the main cause of severe and fatal pathologies worldwide. The use of effective experimental models and methodologies for the study of the pulmonary pathophysiology is necessary to prevent, control and cure these diseases. Plethysmography, a technique for the assessment of lung function, has been widely applied in mice for the characterization of respiratory physiology. However, classical plethysmography methods present technical limitations such as the use of anesthesia and animal immobilization. Whole-body plethysmography (WBP) avoids these issues providing a non-invasive approach for the assessment of the respiratory function in conscious animals. WBP relies on the recording of pressure changes that are produced by the spontaneous breathing activity of an animal placed inside an airtight chamber. During normal respiration, pressure variation is directly proportional to the respiratory pattern of the animal allowing the measurement of the respiratory rate and tidal volume. These parameters are commonly used to evaluate pulmonary function in different physiological and disease models. In contrast to classical plethysmography methods, WBP technique allows reproducible serial measurements as it avoids animal restraint or the use of anesthesia. These key features rend WBP a suitable approach for longitudinal studies allowing the assessment of progressive respiratory alterations in physiological and pathological conditions. This protocol describes the procedures for the measurement of the breathing patterns in mice using the WBP method, the data analysis and results interpretation.

Broad spectrum repairing properties of an extract of Aquaphilus dolomiae on in vitro and ex vivo models of injured skin

BACKGROUND

A biological concentrate was produced from cultures of an Avène aquatic microflora isolate, namely Aquaphilus dolomiae. Some of the beneficial effects on diseased and damaged skin are thought to be due to the presence of this microorganism.

AIMS

An extract of A. dolomiae (A. dolomiae extract-G2, ADE-G2) was evaluated for its wound-healing effects using in vitro and ex vivo models of injured skin.

METHODS

The effect of ADE-G2 on the proliferation of fibroblasts, migration of keratinocytes and re-epithelialization of ex vivo wounded skin explants was measured. Antimicrobial protection by ADE-G2 was measured by analysing the gene expression of a panel of antimicrobial proteins (AMPs) in keratinocytes (RNASE7, S100A7, DEFB4A/B and DEFb103B), as well as the protein encoded by DEFB4A-B (hBD2) in the medium.

RESULTS

ADE-G2 increased fibroblast proliferation and keratinocyte migration, as well as re-epithelialization of wounded ex vivo skin. ADE-G2 induced the expression of all AMP genes analysed in keratinocytes, as well as stimulated the release in to the medium of hBD2 peptide, encoded by DEFB4A/B.

CONCLUSIONS

We have shown the broad spectrum of the repairing properties of the A. dolomiae extract, ADE-G2. These results support the use of ADE-G2 as a promising component for use in formulations aimed at repairing skin, limiting wound superinfection and preventing complicated wounds.

78Predictors of perioperative mortality in adults with congenital heart disease (ACHD): utility of the EuroSCORE and creation of an ACHD-specific score

Introduction

Adult patients with congenital heart disease (ACHD) are a heterogeneous population and a variety of procedures are performed in ACHD centers, which differ significantly from those performed in the general adult population. Therefore, ACHD patients have not been included in the development of risk stratification models, such as the EuroSCORE. We assessed the utility of the components of the EuroSCORE in predicting in-hospital mortality around surgery in a large cohort of ACHD patients and tested a modified risk score for the ACHD population.

Methods

Data were collected retrospectively on all consecutive patients >16 years who underwent congenital heart disease surgery in a large tertiary center in 2015–18. Preoperative characteristics and perioperative outcomes were collected from clinical records and databases. Wilcoxon rank sum test, Fisher's test and Logistic regression analysis were used to identify predictors of in-hospital death. Variables significant on univariate linear regression were used to create a risk score for each patient, either attributing 1 point for each risk factor (unweighted model), or weighing this by its log(Odds ratio) in the logistic regression model (weighted score). Receive operator characteristic (ROC) analysis with calculation of the areas under the curve (AUC) was used to assess the performance of each scoring system in predicting in-hospital mortality.

Results

A total of 476 operations occurred in 459 patients who underwent cardiac surgery during the study period. Age at surgery was 35.9±14.7 years, 258 (56.2%) were male, 231 (51.3%) patients had a previous sternotomy. There were 19 (4.1%) in-hospital deaths. Certain components of EuroSCORE were very rarely observed in our ACHD patients and were not included in the analysis. Of components of the EuroSCORE, female sex (OR 3.79, 95% CI: 1.42–11.89, p=0.01), functional NYHA class>2 (OR 7.65, 95% CI: 2.35–29.26, p=0.001), left ventricle dysfunction (OR 3.14, 95% CI: 1.22–8.01, p=0.02), previous surgery (OR 5.33, 95% CI: 1.41–34.68, p=0.03), emergency or urgent surgery (OR 7.96, 95% CI: 3.1–21.99, p<0.0001), renal dysfunction (MDRD GFR<60 OR 6.56, 95% CI: 1.73–20.52, p=0.002), endocarditis (OR 7.71, 95% CI: 1.6–28.85, p=0.004), and a critical preoperative state (OR 28.65, 95% CI: 5.11–147.93, p<0.0001) were predictive of an adverse perioperative outcome. Moreover, the number of previous sternotomies was predictive of mortality (OR 2.45, 95% CI: 1.58–3.85, p<0.0001). Both the unweighted (AUC 0.78, 95% CI: 70.6–85.3), but especially the weighted risk score (AUC 0.82, 95% CI: 74.8–89) had an optimal discriminative power (Figure).

Conclusions

While several components of the EuroSCORE are relevant to ACHD patients, an ACHD-specific scoring system for predicting perioperative mortality is needed. In this analysis, we propose a simplified risk score for ACHD patients undergoing surgery, which performs well in this population.

Hypertensive disorders during pregnancy and 3 years after delivery in women with gestational hyperglycemia

AIMS

Women with gestational hyperglycemia commonly experience hypertensive disorders during pregnancy. More information is needed about how hypertension develops in these patients over time. We investigated the prevalence of hypertension during and 3 years after pregnancy in Caucasian women with gestational hyperglycemia. We also investigated metabolic syndrome presence, glucose tolerance status, insulin sensitivity and insulin secretion levels in the follow-up period.

METHODS

In a prospective longitudinal study with a 3-year follow-up, we assessed hypertension status and clinical-related characteristics of 103 consecutive women with gestational hyperglycemia sub-grouped according to their hypertensive status during and after pregnancy.

RESULTS

Overall, 29 (28.1%) women had hypertension during pregnancy (24 gestational hypertension; 4 chronic hypertension; 1 preeclampsia). At follow-up 16 (15.5%) women were diagnosed as having hypertension (11 with hypertension in pregnancy; 5 with a normotensive pregnancy). Women with hypertension after pregnancy had higher BMI, metabolic syndrome rate and worse insulin resistance indexes than normotensive women. Weight increase at follow-up (OR 1.17, 95% CI 1.00-1.35) and hypertension in pregnancy (OR 6.72, 95% CI 1.17-38.64) were associated with hypertension after pregnancy.

CONCLUSIONS

Women with gestational hyperglycemia should undergo regular monitoring during and after pregnancy to detect metabolic and clinical impairments and to prevent cardiovascular harm.

Lithium Restores Age-related Olfactory Impairment in the Ts65Dn Mouse Model of Down Syndrome

BACKGROUND & OBJECTIVE

Down syndrome, a genetic condition caused by triplication of chromosome 21, is characterized by widespread neurogenesis reduction and cognitive impairment. Unlike other brain functions, smell is not impaired at early life stages and olfactory deterioration begins to appear in adulthood. Similarly to individuals with Down syndrome, in the Ts65Dn mouse model of Down syndrome smell function is normal at early life stages. Smell impairment only appears in adulthood associated with a reduction in the number of new granule neurons migrated to the olfactory bulb from the subventricular zone. Based on evidence that lithium positively impacts neurogenesis, the goal of current study was to establish whether treatment with lithium restores olfactory bulb neurogenesis and olfactory performance in middle-aged Ts65Dn mice.

METHOD

Euploid and Ts65Dn mice aged 13 months were treated with lithium chow or control chow for one month. Before the end of treatment, mice were injected with BrdU, in order to label proliferating cells. Results showed that in Ts65Dn mice lithium treatment restored the number of neural precursor cells in the subventricular zone of the lateral ventricle, rostral migratory stream and olfactory bulb. This effect was accompanied by restoration of olfactory performance. Unlike in olfactory neurogenic regions, treatment had no neurogenesis-enhancing effect on the subgranular zone of the hippocampal dentate gyrus, indicating that lithium has no generalized positive effect on the brain.

CONCLUSION

Results suggest that lithium may have a positive impact in brain disorders that, similarly to Down syndrome, are characterized by olfactory decline and neurogenesis impairment in the subventricular zone.

Localization of the Sentinel Lymph Node in Breast Cancer by Combined Lymphoscintigraphy, Blue DYE and Intraoperative Gamma Probe

Axillary lymph node status represents the most important prognostic factor in patients with operable breast cancer. A severe limitation of this technique is the relatively high rate of false negative sentinel lymph nodes (>5%). We studied 284 patients suffering from breast cancer; 264 had T1 tumors (16 T1a, 37 T1b and 211 T1c), while 20 had T2 tumors. All patients underwent lymphoscintigraphy 18-h before surgery. At surgery, 0.5 mL of patent blue violet was injected subdermally, and the sentinel lymph node (SN) was searched by gamma probe and by the dye method. The surgically isolated SN was processed for intraoperative and delayed examinations.

The SN was successfully identified by the combined radioisotopic procedure and patent blue dye technique in 278/284 cases (97.9%). Analysis of the predictive value of the SN in relation to the status of the axillary lymph nodes was limited to 191 patients undergoing standard axillary dissection irrespective of the SN status. Overall, 63/191 (33%) identified SNs were metastatic, the SN alone being involved in 37/63 (58.7%) patients; a positive axillary status with negative SN was found in 10/73 (13.7%) patients with metastatic involvement. In T1a-T1b patients the SN turned out to be metastatic in 9/53 patients (17.0%). In 7/9 patients the SN was the only site of metastasis, while in 2/9 patients other axillary lymph nodes were found to be metastatic in addition to the SN. None of the 44 patients in whom the SN proved to be non-metastatic showed any metastatic involvement of other axillary lymph nodes.

Our results demonstrate a good predictive value of SN biopsy in patients with breast cancer; the predictive value was excellent in those subjects with nodules smaller than 1 cm.

Mapping the Sentinel Lymph Node in Malignant Melanoma by Blue Dye, Lymphoscintigraphy and Intraoperative Gamma Probe

Eighty-eight consecutive patients (48 men and 40 women; mean age, 58.9 years; range, 16–84 years) with clinically localized cutaneous melanoma involving the trunk, extremities or head and neck underwent lymphatic mapping at our institution. The primary melanoma had a mean thickness of 2.74 mm (range, 0.95 to 9 mm). Patients were divided into two groups: group A (39 patients) underwent only vital blue dye (VBD) mapping, while group B (49 patients) underwent lymphatic mapping with VBD and radio-guided surgery (RGS) combined. In all patients 1-1.5 mL of VBD was injected subdermally around the biopsy scar 10–20 min before surgery. In group B 37 MBq in 150 μL of 99mTc-HSA nanocolloid was additionally injected intradermally 18 h before surgery (3–6 aliquots injected perilesionally). In all lymphatic basins where drainage was noted the sentinel lymph nodes (SNs) were identified and marked with a cutaneous marker. Final identification of the SN was then performed externally by a hand-held gamma probe. After the induction of anesthesia 0.5–1-0 mL of patent blue V dye was injected intradermally with a 25-gauge needle around the site of the primary melanoma. SNs were examined by routine hematoxylin and eosin (H&E) staining and immunohistochemistry. Patients with histologically positive SN(s) underwent standard lymph node dissection (SLND) in the involved lymph node basin.

The SN was identified in 37/39 patients (94.9%) of group A and in 48/49 patients (98.0%) of group B. Blue dye mapping failed to identify the SN in 5 of the 88 patients (5.8%), while the radioisotope method failed in only 1 of 49 patients (2.0%). Similar results were obtained with the combined use of the two probes. The average number of SNs harvested was 1.9 per basin sampled, which does not differ significantly from the numbers reported by other authors114. The SN was histologically positive in 18 patients (20.5%). None of the 12 patients with a Breslow thickness less than 1.5 mm had positive SNs, whereas 18 of the 77 patients (23.4%) with a Breslow index exceeding 1.5 mm showed metastatic SNs with H&E or immunohistochemistry. The latter all underwent SLND of the affected basin. In 10 patients (55.6%) the SN was the only site of tumor invasion; eight patients (44.4%) with positive SNs had one or more metastatic lymph nodes in the draining basin.

Oxidative stress and mitochondrial dynamics malfunction are linked in Pelizaeus-Merzbacher disease

Pelizaeus‐Merzbacher disease (PMD) is a fatal hypomyelinating disorder characterized by early impairment of motor development, nystagmus, choreoathetotic movements, ataxia and progressive spasticity. PMD is caused by variations in the proteolipid protein gene PLP1, which encodes the two major myelin proteins of the central nervous system, PLP and its spliced isoform DM20, in oligodendrocytes. Large duplications including the entire PLP1 gene are the most frequent causative mutation leading to the classical form of PMD. The Plp1 overexpressing mouse model (PLP‐tg^66/66) develops a phenotype very similar to human PMD, with early and severe motor dysfunction and a dramatic decrease in lifespan. The sequence of cellular events that cause neurodegeneration and ultimately death is poorly understood. In this work, we analyzed patient‐derived fibroblasts and spinal cords of the PLP‐tg^66/66 mouse model, and identified redox imbalance, with altered antioxidant defense and oxidative damage to several enzymes involved in ATP production, such as glycolytic enzymes, creatine kinase and mitochondrial proteins from the Krebs cycle and oxidative phosphorylation. We also evidenced malfunction of the mitochondria compartment with increased ROS production and depolarization in PMD patient's fibroblasts, which was prevented by the antioxidant N‐acetyl‐cysteine. Finally, we uncovered an impairment of mitochondrial dynamics in patient's fibroblasts which may help explain the ultrastructural abnormalities of mitochondria morphology detected in spinal cords from PLP‐tg^66/66 mice. Altogether, these results underscore the link between redox and metabolic homeostasis in myelin diseases, provide insight into the pathophysiology of PMD, and may bear implications for tailored pharmacological intervention.