Near-infrared spectroscopy estimation of combined skeletal muscle oxidative capacity and O2 diffusion capacity in humans

The final steps of the O2 cascade during exercise depend on the product of the microvascular-tointramyocyte PO2 difference and muscle O2 diffusing capacity (DmO2). Non-invasive methods to determine DmO2 in humans are currently unavailable. Muscle oxygen uptake (mVO2) recovery rate constant (k), measured by near-infrared spectroscopy (NIRS) using intermittent arterial occlusions, is associated with muscle oxidative capacity in vivo. We reasoned that k would be limited by DmO2 when muscle oxygenation is low (kLOW), and hypothesized that: i) k in well-oxygenated muscle (kHIGH) is associated with maximal O2 flux in fiber bundles; and ii) Δk (kHIGH-kLOW) is associated with capillary density (CD). Vastus lateralis k was measured in 12 participants using NIRS after moderate exercise. The timing and duration of arterial occlusions were manipulated to maintain tissue saturation index (TSI) within a 10% range either below (LOW) or above (HIGH) half-maximal desaturation, assessed during sustained arterial occlusion. Maximal O2 flux in phosphorylating state was 37.7±10.6 pmol·s−1·mg−1 (~5.8 ml·min−1·100g−1). CD ranged 348 to 586 mm-2. kHIGH was greater than kLOW (3.15±0.45 vs 1.56±0.79 min-1, p\u3c0.001). Maximal O2 flux was correlated with kHIGH (r=0.80, p=0.002) but not kLOW (r=-0.10, p=0.755). Δk ranged -0.26 to -2.55 min-1, and correlated with CD (r=- 0.68, p=0.015). mVO2 k reflects muscle oxidative capacity only in well-oxygenated muscle. Δk, the difference in k between well- and poorly-oxygenated muscle, was associated with CD, a mediator of DmO2. Assessment of muscle k and Δk using NIRS provides a non-invasive window on muscle oxidative and O2 diffusing capacity

Age Dependent Modification of the Metabolic Profile of the Tibialis Anterior Muscle Fibers in C57BL/6J Mice

Skeletal muscle aging is accompanied by mass reduction and functional decline, as a result of multiple factors, such as protein expression, morphology of organelles, metabolic equilibria, and neural communication. Skeletal muscles are formed by multiple fibers that express different Myosin Heavy Chains (MyHCs) and have different metabolic properties and different blood supply, with the purpose to adapt their contraction to the functional need. The fine interplay between the different fibers composing a muscle and its architectural organization determine its functional properties. Immunohistochemical and histochemical analyses of the skeletal muscle tissue, besides evidencing morphological characteristics, allow for the precise determination of protein expression and metabolic properties, providing essential information at the single-fiber level. Aiming to gain further knowledge on the influence of aging on skeletal muscles, we investigated the expression of the MyHCs, the Succinate Dehydrogenase (SDH) activity, and the presence of capillaries and Tubular Aggregates (TAs) in the tibialis anterior muscles of physiologically aging C57BL/6J mice aged 8 (adult), 18 (middle aged), and 24 months (old). We observed an increase of type-IIB fast-contracting fibers, an increase of the oxidative capacity of type-IIX and -IIA fibers, a general decrease of the capillarization, and the onset of TAs in type-IIB fibers. These data suggest that aging entails a selective modification of the muscle fiber profiles

Long-term resveratrol treatment improves the capillarization in the skeletal muscles of ageing C57BL/6J mice

We recently showed that the treatment with Resveratrol (RES) contrasts the effects of ageing on the skeletal muscle (SKM), reduces the appearance of tubular aggregates (TAs), and improves the fatigue resistance. Since fatigue resistance depends on the SKM capillary network, and RES has been described to improve vascularisation, we analysed the SKM capillarization in naturally age- ing C57BL/6J male mice, fed with 0.04% RES in the diet for 6months, which showed a better fatigue resistance in a previous work. Our data show an inverse correlation between the number of capillaries per fibre (CAF) and TAs in both control and treated type IIB fibres, and an increase of CAF in ageing SKM upon RES-treatment. The present work suggests that capillarization is one of the determinants of the development of TAs and fatigue resistance, and that RES can be con- sidered a good candidate to counteract capillary rarefaction in the SKM tissue

A short-term treatment with resveratrol improves the inflammatory conditions of Middle-aged mice skeletal muscles

4noSarcopenia starts around the age of 40, causes the loss of 8% of muscle mass every 10 years, and is accompanied by functional deficit, chronic low-grade inflammation, and can result in several negative health outcomes. Considering the early and gradual onset of sarcopenia, the time window of the potential interventions could be crucial for the exertion of a beneficial effect. We recently showed that the long-term supplementation with Resveratrol contrasts sarcopenia in naturally ageing C57BL/6 mice. Aiming to understand the effects of a short term treatment, we administered intraperitoneally middle aged male mice with 20 mg/kg body weight Resveratrol daily for 5 weeks. Although we could not observe major differences in the histological properties of SKMs, we detected a significant decrease of Cox-2 in RES-treated muscles, confirming the antiinflammatory action of Resveratrol, and suggesting that its anti-inflammatory action precedes modifications to SKM fibres.noneembargoed_20250113Sirago, Giuseppe; Toniolo, Luana; Crea, Emanuela; Giacomello, EmilianaSirago, Giuseppe; Toniolo, Luana; Crea, Emanuela; Giacomello, Emilian

AXL-Receptor Targeted 14FN3 Based Single Domain Proteins (Pronectins™) from 3 Synthetic Human Libraries as Components for Exploring Novel Bispecific Constructs against Solid Tumors

A highly specific AXL-receptor targeted family of non-immunoglobulin, single domain protein binders (Pronectins™) have been isolated from three (3) synthetic libraries that employ the human scaffold of the 14th domain of Fibronectin III (14FN3) and evolutionary CDRs diversity of over 25 billion loop sequences. The three libraries, each containing diversity in two loops, were designed to expand upon a human database of more than 6000 natural scaffold sequences and approximately 3000 human loop sequences. We used a bioinformatic-based approach to maximize "human" amino acid loop diversity and minimize or prevent altogether CDR immunogenicity created by the use of mutagenesis processes to generate diversity. A combination of phage display and yeast display was used to isolate 59 AXL receptor targeted Pronectins with KD ranging between 2 and 100 nM. FACS analysis with tumor cells over-expressing AXL and the use of an AXL knock-out cell line allowed us to identify Pronectin candidates with exquisite specificity for AXL receptor. Based upon several in vitro cell-based tests, we selected the best candidate, AXL54, to further characterize its in vitro cancer cells killing activity. Finally, AXL54 was used to produce the first bi-specific T cell engager protein (AXL54 [Pronectin]-linker-scFV CD3), a "new in class" protein for further testing of its anti-tumor activity in vitro and in vivo

Video-assisted thyroidectomy

BACKGROUND: In 1998, we developed a technique for video-assisted thyroidectomy (VAT). In this article we report on the entire series of patients who underwent VAT and discuss the results obtained. STUDY DESIGN: Forty-seven patients were selected for VAT. Eligibility criteria were: thyroid nodules of 35 mm or less in maximum diameter; estimated thyroid volume within normal range or slightly enlarged; small, low-risk papillary carcinomas; neither previous neck surgery nor irradiation; and no thyroiditis. After a learning period, VAT was proposed also for completion thyroidectomy (of previous video-assisted lobectomy) and nodules with maximum diameter up to 45 mm. The procedure is performed by a totally gasless video-assisted technique through a single 1.5- to 2.0-cm skin incision. Dissection is performed under endoscopic vision using a technique very similar to conventional operation. RESULTS: Fifty-three VATs were attempted on 47 patients. Thirty-three lobectomies, 10 total thyroidectomies, and 6 completion thyroidectomies were successfully performed. Six patients with papillary carcinoma underwent central neck lymph node removal by the same access. Mean operative time was 86.8 minutes for lobectomy, 116.0 minutes for total thyroidectomy, and 77.5 minutes for completion thyroidectomy. Conversion rate was 7.5%. Postoperative complications included one transient recurrent nerve palsy, three transient symptomatic postoperative hypocalcemias, and one wound infection. The cosmetic result was considered excellent by most of the patients who successfully underwent VAT. CONCLUSIONS: VAT is feasible and safe and allows for an excellent cosmetic result. Not all patients are eligible for this procedure, but in selected cases it can be a valid option for the surgical treatment of thyroid diseases

Near‐infrared spectroscopy estimation of combined skeletal muscle oxidative capacity and O2 diffusion capacity in humans

The final steps of the O2 cascade during exercise depend on the product of the microvascular-to-intramyocyte PO2${P}_{{{\rm{O}}}_{\rm{2}}}$ difference and muscle O2 diffusing capacity ( DmO2$D{{\rm{m}}}_{{{\rm{O}}}_2}$ ). Non-invasive methods to determine DmO2$D{{\rm{m}}}_{{{\rm{O}}}_2}$ in humans are currently unavailable. Muscle oxygen uptake (m V̇O2${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ ) recovery rate constant (k), measured by near-infrared spectroscopy (NIRS) using intermittent arterial occlusions, is associated with muscle oxidative capacity in vivo. We reasoned that k would be limited by DmO2$D{{\rm{m}}}_{{{\rm{O}}}_2}$ when muscle oxygenation is low (kLOW ), and hypothesized that: (i) k in well oxygenated muscle (kHIGH ) is associated with maximal O2 flux in fibre bundles; and (ii) ∆k (kHIGH  - kLOW ) is associated with capillary density (CD). Vastus lateralis k was measured in 12 participants using NIRS after moderate exercise. The timing and duration of arterial occlusions were manipulated to maintain tissue saturation index within a 10% range either below (LOW) or above (HIGH) half-maximal desaturation, assessed during sustained arterial occlusion. Maximal O2 flux in phosphorylating state was 37.7 ± 10.6 pmol s-1  mg-1 (∼5.8 ml min-1  100 g-1 ). CD ranged 348 to 586 mm-2 . kHIGH was greater than kLOW (3.15 ± 0.45 vs. 1.56 ± 0.79 min-1 , P < 0.001). Maximal O2 flux was correlated with kHIGH (r = 0.80, P = 0.002) but not kLOW (r = -0.10, P = 0.755). Δk ranged -0.26 to -2.55 min-1 , and correlated with CD (r = -0.68, P = 0.015). m V̇O2${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ k reflects muscle oxidative capacity only in well oxygenated muscle. ∆k, the difference in k between well and poorly oxygenated muscle, was associated with CD, a mediator of DmO2$D{{\rm{m}}}_{{{\rm{O}}}_2}$ . Assessment of muscle k and ∆k using NIRS provides a non-invasive window on muscle oxidative and O2 diffusing capacity. KEY POINTS: We determined post-exercise recovery kinetics of quadriceps muscle oxygen uptake (m V̇O2${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ ) measured by near-infrared spectroscopy (NIRS) in humans under conditions of both non-limiting (HIGH) and limiting (LOW) O2 availability, for comparison with biopsy variables. The m V̇O2${\dot{V}}_{{{\rm{O}}}_{\rm{2}}}$ recovery rate constant in HIGH O2 availability was hypothesized to reflect muscle oxidative capacity (kHIGH ) and the difference in k between HIGH and LOW O2 availability (∆k) was hypothesized to reflect muscle O2 diffusing capacity. kHIGH was correlated with phosphorylating oxidative capacity of permeabilized muscle fibre bundles (r = 0.80). ∆k was negatively correlated with capillary density (r = -0.68) of biopsy samples. NIRS provides non-invasive means of assessing both muscle oxidative and oxygen diffusing capacity in vivo

Choroid Plexus Carcinoma in Adults: Literature Review and First Report of a Location into the Third Ventricle

Choroid plexus carcinoma (CPC) is a rare intraventricular neoplasm originating from choroid plexus. CPC is the most aggressive choroid plexus tumor. Almost all the CPCs are detected in children, and the preferred location is the lateral ventricle. We reviewed the literature to evaluate the state of the art concerning the management of CPC in adults and report the first case described of the extremely rare localization into the third ventricle. A 38-year-old woman presented a medical history of Parinaud syndrome and occasional facial weakness. Brain magnetic resonance imaging revealed a mass lesion in the pineal region and posterior part of the third ventricle with obstructive hydrocephalus. She underwent subtotal resection through a supracerebellar infratentorial approach. After the histopathological diagnosis of CPC, the patient underwent a second surgery with gross total resection and adjuvant radiotherapy. CPC in adults, given its extreme rarity, does not have a standardized treatment. Gross total resection should be the first step of the treatment: however, according to the literature, gross total resection is achieved only in 40-75% of cases in CPC as opposed to 95% in choroid plexus papilloma, mainly due to the difficulty in managing a highly vascularized tumor in such a deep location. Chemotherapy has not an established role and adjuvant treatment is based on radiotherapy. In the case described hereby the gross total resection associated with surgical treatment of hydrocephalus and adjuvant radiotherapy has achieved a good clinical and radiological outcome

Are brown tumours a forgotten disease in developed countries?

Brown tumours (BT), an expression of osteitis fibrosa cystic due to primary hyperparathyroidism (pHPT), can occasionally be mistaken for malignancy. Among 615 patients who underwent parathyroidectomy for pHPT in our institution, the medical records of three patients affected by BT were reviewed. The first patient underwent surgical removal of the orbital mass for a suspected lachrymal gland neoplasm. The remaining two patients underwent, respectively, leg amputation and femur resection for a suspected bone malignancy. Final histology showed a BT in three cases. All three patients were admitted to our Division and underwent successful parathyroidectomy for parathyroid adenoma in two cases and for parathyroid carcinoma in the remaining case. When faced with an osteolithic bone lesion, complete evaluation of medical history, biochemical and radiographic findings can help to reach a correct diagnosis and avoid unnecessary bone resections