Temporal optimization of exercise to lower fasting glucose levels.

Exercise stimulates glucose uptake and increases insulin sensitivity acutely. Temporally optimizing exercise timing may minimize the nocturnal rise in glucose levels. This study examined the effect of exercise timing on evening and overnight glucose concentrations in individuals who were non-obese with normal fasting glucose levels (Non-Ob; n = 18) and individuals with obesity (OB) with impaired fasting glucose levels (OB+IFG) and without (n = 16 and n = 18, respectively). Subjects were studied on three occasions (no exercise (NOEX)), morning exercise (AMEX; 0700 h) and evening exercise (PMEX; 2000 h). The evening meal was provided (1800 h) and blood samples were taken from 1740 to 0700 h and morning endogenous glucose production (EGP) was measured. Glucose and insulin concentrations increased with the dinner meal with peak concentrations being higher in OB+IFG than in OB and Non-Ob (P = 0.04). In OB+IFG, evening glucose concentrations rose above baseline levels at about 2300 h, with the glucose concentrations staying somewhat lower with AMEX and PMEX until ∼0500 h than with NOEX. In OB+IFG, insulin concentrations decreased following the dinner meal and waned throughout the night, despite the rising glucose concentrations. In the OB and Non-Ob individuals following the dinner meal, no increase in glucose concentrations occurred in the evening period and insulin levels mirrored this. No difference was observed in the morning fasting glucose levels between study days or between groups. Regardless of time of day, exercise delays the evening rise in glucose concentrations in adults with OB+IFG but does not lower morning fasting glucose levels or improve the synchrony between glucose and insulin concentrations. KEY POINTS: Insulin resistance and type 2 diabetes have been linked to disturbances of the core clock, and glucose tolerance demonstrates a diurnal rhythm in healthy humans with better glucose tolerance in the morning than in the afternoon and evening. Skeletal muscle is a primary site for insulin resistance in people with impaired glucose tolerance. In individuals with obesity and impaired fasting glucose levels (OB+IFG), following a dinner meal, glucose concentrations started to rise and continues throughout the night, resulting in elevated glucose levels, while concomitantly, insulin levels are waning. Exercise, regardless of the time of day, suppressed the rise in glucose levels in OB+IFG for many hours during the night but did not lower morning fasting glucose levels. Morning exercise was not quite as effective as evening exercise.

Malignant pleural mesothelioma immune microenvironment and checkpoint expression: correlation with clinical-pathological features and intratumor heterogeneity over time.

Background: Tumor immune microenvironment (TME) plays a key role in malignant pleural mesothelioma (MPM) pathogenesis and treatment outcome, supporting a role of immune checkpoint inhibitors as anticancer approach. This study retrospectively investigated TME and programmed death ligand 1 (PD-L1) expression in naïve MPM cases and their change under chemotherapy. Patients and methods: Diagnostic biopsies of MPM patients were collected from four Italian and one Slovenian cancer centers. Pathological assessment of necrosis, inflammation, grading, and mitosis was carried out. Ki-67, PD-L1 expression, and tumor infiltrating lymphocytes were detected by immunohistochemistry. When available, the same paired sample after chemotherapy was analyzed. Pathological features and clinical characteristics were correlated to overall survival. Results: TME and PD-L1 expression were assessed in 93 and 65 chemonaive MPM samples, respectively. Twenty-eight samples have not sufficient tumor tissue for PD-L1 expression. Sarcomatoid/biphasic samples were characterized by higher CD8+ T lymphocytes and PD-L1 expression on tumor cells, while epithelioid showed higher peritumoral CD4+ T and CD20+ B lymphocytes. Higher CD8+ T lymphocytes, CD68+ macrophages, and PD-L1 expression were associated with pathological features of aggressiveness (necrosis, grading, Ki-67). MPM cases characterized by higher CD8+ T-infiltrate showed lower response to chemotherapy and worse survival at univariate analysis. Patients stratification according to a combined score including CD8+ T lymphocytes, necrosis, mitosis, and proliferation index showed median overall survival of 11.3 months compared with 16.4 months in cases with high versus low combined score (P < 0.003). Subgroup exploratory analysis of 15 paired samples before and after chemotherapy showed a significant increase in cytotoxic T lymphocytes in MPM samples and PD-L1 expression in immune cells. Conclusions: TME enriched with cytotoxic T lymphocytes is associated with higher levels of macrophages and PD-L1 expression on tumor cells and with aggressive histopathological features, lower response to chemotherapy and shorter survival. The role of chemotherapy as a tumor immunogenicity inducer should be confirmed in a larger validation set.

Immediate and Catastrophic Antibody-Mediated Rejection in a Lung Transplant Recipient With Anti-Angiotensin II Receptor Type 1 and Anti-Endothelin-1 Receptor Type A Antibodies.

Preexisting donor-specific anti-HLA antibodies (DSAs) have been associated with reduced survival of lung allografts. However, antibodies with specificities other than HLA may have a detrimental role on the lung transplant outcome. A young man with cystic fibrosis underwent lung transplantation with organs from a suitable deceased donor. At the time of transplantation, there were no anti-HLA DSAs. During surgery, the patient developed a severe and intractable pulmonary hypertension associated with right ventriular dysfunction, which required arteriovenous extracorporeal membrane oxygenation. After a brief period of clinical improvement, a rapid deterioration in hemodynamics led to the patient's death on postoperative day 5. Postmortem studies showed that lung specimens taken at the end of surgery were compatible with antibody-mediated rejection (AMR), while terminal samples evidenced diffuse capillaritis, blood extravasation, edema, and microthrombi, with foci of acute cellular rejection (A3). Immunological investigations demonstrated the presence of preexisting antibodies against the endothelin-1 receptor type A (ETA R) and the angiotensin II receptor type 1 (AT1 R), two of the most potent vasoconstrictors reported to date, whose levels slightly rose after transplantation. These data suggest that preexisting anti-ETA R and anti-AT1 R antibodies may have contributed to the onset of AMR and to the catastrophic clinical course of this patient.

Size-dependent bandgap and particle size distribution of colloidal semiconductor nanocrystals.

A new analytical expression for the size-dependent bandgap of colloidal semiconductor nanocrystals is proposed within the framework of the finite-depth square-well effective mass approximation in order to provide a quantitative description of the quantum confinement effect. This allows one to convert optical spectroscopic data (photoluminescence spectrum and absorbance edge) into accurate estimates for the particle size distributions of colloidal systems even if the traditional effective mass model is expected to fail, which occurs typically for very small particles belonging to the so-called strong confinement limit. By applying the reported theoretical methodologies to CdTe nanocrystals synthesized through wet chemical routes, size distributions are inferred and compared directly to those obtained from atomic force microscopy and transmission electron microscopy. This analysis can be used as a complementary tool for the characterization of nanocrystal samples of many other systems such as the II-VI and III-V semiconductor materials.

The Use of Integra Dermal Regeneration Template Versus Flaps for Reconstruction of Full-Thickness Scalp Defects Involving the Calvaria: A Cost-Benefit Analysis.

BACKGROUND: INTEGRA® Dermal Regeneration Template is a well-known and widely used acellular dermal matrix. Although it helps to solve many challenging problems in reconstructive surgery, the product cost may make it an expensive alternative compared to other reconstruction procedures. This retrospective study aims at comparing INTEGRA-based treatment to flap surgery in terms of cost and benefit. PATIENTS AND METHODS: We considered only patients treated for scalp defects with bone exposure in order to obtain two groups as homogeneous as possible. We identified two groups of patients: 17 patients treated with INTEGRA and 18 patients treated with flaps. All patients were admitted in our institution between 2004 and 2010, and presented a defect of the scalp following trauma or surgery for cancer, causing a loss of the soft tissues of the scalp with bone exposure without pericranium. To calculate the cost in constant euros of each treatment, three parameters were evaluated for each patient: cost of the surgical procedure (number of doctors and nurses involved, surgery duration, anesthesia, material used for surgery), hospitalization cost (hospitalization duration, dressings, drugs, topical agents), and outpatient cost (number of dressing changes, personnel cost, dressings type, anti-infective agents). The statistical test used in this study was the Wilcoxon Mann-Whitney (α = 0.05). RESULTS: No significant difference was characterized between the two groups for gender, age, presence of diabetes, mean defect size, and number of surgical procedures. All patients healed with good quality and durable closure. The median total cost per patient was €11,121 (interquartile range (IQR) 8327-15,571) for the INTEGRA group and €7259 (IQR 1852-24,443) for the flap group (p = 0.34). A subgroup of patients (six patients in the INTEGRA group and five patients in the flap group) showing defects larger than 100 cm2 were considered in a second analysis. Median total cost was €11,825 (IQR 10,695-15,751) for the INTEGRA group and €23,244 (IQR 17,348-26,942) for the flap group. CONCLUSION: Both treatments led to a good healing of the lesions with formation of soft and resistant tissue. No significant difference was characterized between the two groups for days of hospitalization and costs. In cases of patients with defects larger than 100 cm2 for whom major surgery is needed, the treatment with INTEGRA seemed to be less expensive than the treatment with free flaps or pedicle flaps. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the A5 online Instructions to Authors. www.springer.com/00266 .

PCDD/Fs in the soils in the province of Trento: 10 years of monitoring.

This paper presents a 10-year overview of the dioxins and furans (PCDD/Fs) content in soils in the province of Trento (Italy). The aim was to compare the results found in the Valsugana valley where there is a steel-making plant with other locations within the province. During 2002 and from 2005 to 2010, campaigns were carried out in order to obtain a background reference in terms of micropollutants, in view of the possible construction of a municipal solid waste (MSW) incinerator in Trento. In 2009, a campaign was performed for the environmental characterization of the Valsugana valley, the town of Trento and its surroundings, in order to help assess the impact of the steel-making plant. In 2012, another campaign was carried out by the Department of Civil and Environmental Engineering of Trento, in order to monitor the soils in the area around the steel mill. All the campaigns showed relatively low concentrations of PCDD/Fs, both in protected areas and in the areas close to the industrial plants. No critical situations were identified, as also confirmed by an estimation of the potential daily PCDD/F intake by children subject to accidental ingestion of soil.

Denture Adhesives Associated with Silver Vanadate: Antimicrobial Approach Against Multi- Species Biofilms on Acrylic Resin Surfaces.

Alternatives have been sought to add an antimicrobial property to denture adhesives. This study evaluated the antimicrobial potential of adhesives associated with nanostructured silver vanadate decorated with silver nanoparticles (ß-AgVO3). Specimens in acrylic resin were treated with the adhesives associated with ß-AgVO3 (1%, 2.5%, 5% and 10%). As control, specimens treated only with Ultra Corega Cream (UCC) or Ultra Corega Powder (UCP) adhesive were used. Multispecies biofilm of Candida albicans, Candida glabrata, Streptococcus mutans and Staphylococcus aureus was evaluated by counting colony forming units per milliliter (CFU/mL), colorimetric assay and fluorescence microscopy. The data were analyzed using the two-way analysis of variance (ANOVA) and Bonferroni multiple comparisons test (α=0.05). For both adhesives, a small amount of ß-AgVO3 (1%) completely inhibited S. mutans (P⟨0.05). For the other microorganisms, there was a reduction in metabolic activity and complete inhibition in the groups with intermediate or greater amounts of nanomaterial (P⟨0.05), except for C. albicans, which was reduced (P⟨0.05) but not completely inhibited in UCP. Microscopy that showed less biofilm in the groups with ß-AgVO3 and in the UCC than UCP. Denture adhesives in powder and cream form with ß-AgVO3 showed potential antimicrobial activity against multispecies biofilm. Powder adhesive showed higher biofilm formation.

New surgical trends in breast cancer treatment: conservative interventions and oncoplastic breast surgery.

AIM: From radical mastectomy by Halstedt to quadrantectomy by Veronesi, surgical treatment of breast cancer has become more and more conservative in order to preserve women quality of life. We analyzed the evolution of breast interventions through a nine-year period. METHODS: We collected data about all breast surgery interventions performed between 2002 and 2010 in our Department Of Surgery, focusing on patients' age, tumor histology, TNM classification, hormonal status, intervention radicality on the breast and axilla, and eventual plastic surgery. Data were analyzed by R (version 2.14.2), considering significant P<0.05. RESULTS: A total of 3320 breast surgery interventions were performed on 2300 patients. Absolute yearly number of interventions has strongly increased with the introduction of the mammography screening (291 to 430). Conservative breast surgery (55% to 62%) and skin-sparing mastectomy (1% to 8%) have been performed more frequently in premenopausal patients, and significantly increased in time, with a consequent decrease of classical radical mastectomy (38 to 15%) but an increase of margins widening after primary surgery (2% to 6%). Sentinel lymph node biopsy is mostly replacing complete axillary lymph node dissection (93% to 31%). Skin-glandular reshaping progressively increased (up to 20%) as also breast reconstruction (23% to 40%), which since 2008 has been performed also in women older than 75 years, while flaps have been used in strictly selected patients. CONCLUSION: Conservative surgery represents the target of current breast cancer treatment where possible, and skin-sparing mastectomy an interesting alternative to classical one when radicality is required. Sentinel lymph node biopsy has replaced complete axillary lymph node dissection by clinically negative nodal status. Breast reshaping and reconstruction are increasing in every age group, including women older than 75 years.

Endobronchial valve for secondary pneumothorax in a severe emphysema patient.

Secondary pneumothorax represents a challenging problem in patients with chronic obstructive pulmonary disease, due to their compromised health status. In this case, an endobronchial one-way valve was inserted in the left lower lobe by flexible bronchoscopy, resulting in a complete resolution of air leak and lung reexpansion. Endobronchial valve could represent a new option for the management of persistent air leak in patients not suitable for surgical procedures.

Synovial sarcoma: CT imaging of a rare primary malignant tumour of the thorax.

PURPOSE: This paper presents computed tomography (CT) features of three patients with primary synovial sarcoma of the lung (PSSL) who came to our attention and underwent surgery; reviews of the literature on this rare thoracic tumour are also presented. MATERIALS AND METHODS: The patients, all men, with a mean age of 58 years, underwent clinical and radiological re-evaluation after receiving a histological diagnosis. None of the patients had multifocal disease or other concomitant neoplasms. All patients had undergone both chest X-rays and computed tomography, and two had also been studied with positron emission tomography (PET)-CT. Two patients underwent surgical removal of the tumour, whereas the third initially underwent surgery (following an incorrect diagnosis) and then thoracoscopic biopsy of the pleural lesions that subsequently arose. RESULTS: In each case, chest X-rays showed changes, with the presence of pulmonary masses noted in all patients. In one patient, pleural effusion was also visible. CT scans showed parenchymal masses that were largely of a colliquative nature (in two out of three patients). Ipsilateral pleural effusion was present in two patients, associated in one with solid nodules within the pleura. Mediastinal lymphadenopathy, which was not radiologically significant, was present in only one patient. The two patients who also underwent PET-CT examination showed pathological tracer uptake confined to the lesion site without other thoracoabdominal or musculoskeletal localisations. CT-guided biopsy, performed in one patient only, was positive for mesenchymal tumour. In the two patients who underwent surgery, a definitive diagnosis of monophasic synovial sarcoma of the lung was made. The diagnosis of monophasic synovial sarcoma in the third patient was confirmed using thoracoscopic biopsy DISCUSSION: Both in the cases described and in those identified in the literature review, standard chest X-rays mainly showed a parenchymal mass of pleural origin with either irregular or well-defined margins. CT characteristics are more definite, with evidence of a mass with regular and sharply defined margins, occasionally polycyclic, with inhomogeneous density due to the presence of colliquative areas within the tumour. CONCLUSIONS: Although PSSL is a rare tumour, a pulmonary mass of inhomogeneous density, associated with pleural effusion but without lymphadenopathy, detected in an asymptomatic or poorly symptomatic patient, should lead to PSSL being considered in the differential diagnosis, provided that metastases from the more common synovial sarcomas of the musculoskeletal system have been excluded.

Theoretical and experimental studies of stressed nanoparticles of II-VI semiconductors.

A theoretical and experimental study of isolated nanoparticles of II-VI semiconductor materials has been done. Using the framework of the effective mass model, the optical absorption spectrum of distributions of spherical quantum dots, freestanding, and under compressive or tensile stress, has been examined theoretically. The theoretical results allow one to foresee the absorption spectra of quantum dots made of a series of materials and having any size. The syntheses of colloidal quantum dots of CdS and CdSe has also been performed through wet chemical routes and characterized by means of optical techniques. The values of the strains in the synthesized quantum dots were inferred from a correlation established between the theoretical and the experimental results.

Growth kinetics of CdTe colloidal nanocrystals.

The growth kinetics of CdTe colloidal nanocrystals has been analyzed quantitatively by means of dynamic light scattering and photoluminescence measurements. The growth rates, size distributions, critical radii, and diffusion constants have been calculated in the framework of the Sugimoto theoretical model. A two-step diffusion-controlled growth regime has been proposed for the reported synthesis and a set of relations for the time evolution of the size distribution has been derived and discussed in the sense of the size distribution focusing concept.

The role of immune microenvironment in small-cell lung cancer: Distribution of PD-L1 expression and prognostic role of FOXP3-positive tumour infiltrating lymphocytes.

INTRODUCTION: The prognosis of small-cell lung cancer (SCLC) is dismal and new effective therapies are needed. Immunotherapy looks promising, but no molecular predictive markers are currently available, and data on immune microenvironment are very limited. METHODS: We retrospectively analysed 104 SCLC cases. Immunohistochemistry evaluation of PD-L1 was performed both on tumour cells (TCs) and on tumour-infiltrating immune cells (TIICs) by using anti-PD-L1 22C3 antibody (DAKO) and categorised by using 1% as cut-off point. Tumour-infiltrating lymphocytes (TILs) were characterised by using anti-CD8 and anti-FOXP3 antibodies. Semi-quantitative score was used and categorised as positive versus negative/low. The relation of molecular markers with prognosis and with clinical variables was evaluated. RESULTS: The analysis included 66 stage I-III patients (48 surgically resected, 18 treated with radical-intent chemoradiotherapy) and 38 metastatic cases. In the overall study population, PD-L1 was expressed on TCs and TIICs in 25% and 40% of cases, respectively. The proportion of PD-L1-positive cases was significantly higher in stage I-III versus metastatic patients (32% versus 13%, p: 0.034 for TCs; 51.5% versus 21% for TIICs, p: 0.002). CD8- and FOXP3-positive TILs were present in 59% and 72% of samples, respectively. The presence of FOXP3-TILs was associated with improved prognosis among non-metastatic patients, with a hazard ratio for survival of 0.32 (95% confidence interval [CI]: 0.16-0.7, p: 0.006) for univariate analysis, and 0.37 (95% CI: 0.17-0.81, p: 0.013) for multivariate analysis. CONCLUSIONS: Immune contexture of SCLC may differ according to stage. The presence of FOXP3-positive TILs is a potential prognostic marker for stage I-III SCLCs and warrants further investigation.

Chromate differentially affects the expression of a high-affinity sulfate transporter and isoforms of components of the sulfate assimilatory pathway in Zea mays (L.).

In this study the chromate accumulation and tolerance were investigated in ZEA MAYS L. in relation to sulfur availability since sulfate may interact with chromate for transport into the cells. Chromate inhibited sulfate uptake when supplied to plants for a short-term period, whereas phosphate uptake remained unchanged. Sulfate absorption was also reduced in S-starved (-S) and S-supplied (+S) plants treated for 2 d with 0.2 mM chromate and the concomitant repression of the root high-affinity sulfate root transporter ZMST1;1 transcript accumulation was observed. Conversely, the plasma membrane H (+)-ATPase MHA2 was unaffected by chromate in +S plants, allowing to exclude a general effect of chromate on the active membrane transport. As observed for sulfate uptake, chromate uptake was enhanced in -S condition and decreased in both +S and -S plants after 2 d of Cr treatment. Chromate reduced the concentration of sulfur and sulfate in +S plants to the basal level of -S plants, and maximum chromium accumulation was recorded in S-deprived plants. Analysis of transcript abundance of genes involved in sulfate assimilation revealed differential regulation by chromate, which was only partly related to sulfur availability and to the levels of thiols. This work shows for the first time that chromate specifically represses sulfate uptake, and such repression occurs without the implication of the candidate regulatory metabolites of the sulfate transport system in plants.

Favorable tissue effects of quantum molecular resonance device (Vesalius) compared with standard electrocautery. A novel paradigm in lung surgery.

BACKGROUND: Electrosurgical devices are largely employed in thoracic surgery but their use is burdened by extensive necrosis and second intention healing. METHODS: A rat model of thoracotomy was performed on 46 adult male rats using a standard electrocautery or a new quantum molecular resonance (QMR) instrument called Vesalius. Skin, muscle and lung specimens were obtained immediately and 2 weeks after surgery to evaluate acute and late effects. RESULTS: Both in the short- and long-term study, Vesalius produced less severe tissue damage than that of standard electrocautery. CONCLUSIONS: The use of the QMR device may provide an alternative to gold-standard electrosurgical devices in thoracic surgery.

Direct link between fluoranthene biodegradation and the mobility and sequestration of its residues during aging.

The aim of this study was to assess the influence of the polycyclic aromatic hydrocarbons (PAH)-degrading activity in the fate of fluoranthene in soils. Three soil samples with different degrading activities (an industrial soil, the same industrial soil after biostimulation, and an agricultural soil) were spiked with 14C-fluoranthene and incubated for 6 mo with monitoring of biodegradation and mineralization. To follow the distribution of the 14C-fluoranthene residues (i.e., 14C-fluoranthene and its degradation products) among the soil compartments, we performed successively leaching, centrifugation (to collect intra-aggregate pore water), solvent extraction, and combustion of the soil columns. In the industrial soil, no mineralization of 14C-fluoranthene was observed, and only 3% of the initial 14C-activity was non-extractable (with acetone:dichloromethane) after 165 d of incubation. The biostimulation (addition of unlabeled polycyclic aromatic hydrocarbons) increased the degrading activity in this soil (59% of 14C-fluoranthene was mineralized) and increased the residues sequestration (13% of 14C-activity was non-extractable). The microflora of the agricultural soil mineralized 14C-fluoranthene more slowly and to a lesser extent (25%) than the biostimulated soil, but a higher amount of 14C-activity was sequestered (41%). Thus, the rate and extent of 14C-fluoranthene mineralization seemed to be related to the 14C-activity sequestration by controlling the accumulation of degradation products in the soil. 14C-Fluoranthene biodegradation enhanced the concentration of 14C-polar compounds in the intra-aggregate pore water. Our results point out the close link between fluoranthene biodegradation and two key aging processes, diffusion and sequestration, in soils. Biodegradation controls the mobility and sequestration of residues by transforming fluoranthene into more polar molecules that can diffuse into the intra-aggregate pore water and then might become bound to the matrix or entrapped in the microporosity.

Delayed effect of nitric oxide synthase inhibition on the survival of rats after acute decompression.

AIM: The formation of bubbles in the blood stream together with the ensuing sickness after rapid decompression is assumed to depend on the physiological condition of the vascular system. In order to gain insight into the vascular function of nitric oxide in acute decompression sickness, the effects of the nitric oxide synthase inhibition by N(omega)-nitro-L-arginine methyl ester was studied in rats. METHODS: Wistar rats under anaesthesia were exposed to hyperbaric conditions for two hours and decompressed approximately 2.5 hours after a single subcutaneous injection of N(omega)-nitro-L-arginine methyl ester. Scalar doses and different pressures were tested. RESULTS: The fraction of the rats that died after decompression was greater in rats treated with N(omega)-nitro-L-arginine methyl ester at doses greater than 8 mg Kg-1 body weight compared to untreated rats. CONCLUSION: Although we have not excluded effects of nitric oxide synthase inhibition on distribution of perfusion and therefore inert gas elimination from tissue during decompression as a factor, this result highlights a delayed benefit of nitric oxide synthase activity in preventing death in acute decompression sickness.

Aminotransferase changes in burned patients.

The time course of serum transaminases (alanine aminotransferase and aspartate aminotransferase) has been followed in 30 selected consecutive patients presenting burn sizes ranging from 10% to 95% of the total body surface (mean 43.13) and a survival index from 0.99 to 0.00 (mean 0.59). The results show that in all the patients both transaminases change in parallel, increasing in 18 patients (60%). In nearly all patients both enzymes increase during the second week after injury and aspartate aminotransferase increases later than alanine aminotransferase. The higher transaminase levels are noted in moderately ill patients. No clear correlation between the overall increase of transaminases and the extent of burned surface area has been found. We conclude that functional liver alterations mostly contribute to the increase of serum transaminases in burns.

Altered surfactant synthesis and function in rats with diet-induced hyperlipidemia.

Altered lung function in hyperlipidemic patients has been reported by many authors. An alteration of surfactant synthesis has been suggested. Isolated lungs of rats rendered hyperlipidemic by suitable diets display an increased distensibility at maximal inflation and a higher degree of alveolar stability during deflation. These alterations are related to modifications of surfactant properties. Lung lavage fluid obtained from hyperlipidemic rats displays an increase in percent content of phosphatidylglycerol and a decrease of phosphatidylethanolamine. The percent content of phosphatidylglycerol correlates with the circulating levels if free fatty acids (FFA). It is suggested that FFA might affect the activity of enzymes operating in lung phospholipid synthesis. The reported increase of surfactant phosphatidylglycerol might explain the increment of alveolar stability observed in hyperlipidemic rats.