Spirituality, Social Support, and Diabetes: A Cross-Sectional Study of People Enrolled in a Nurse-Led Diabetes Management Program in Peru.

INTRODUCTION: In Peru, people living with diabetes mellitus (PLDM) represent 7% of the adult population, each with a $54,000 lifetime cost. For Latinos, spirituality provides meaning and purpose of life while social support affects behavioral choices and adherence decisions. The purpose of this study was to determine the relationship between spirituality and social support for PLDM participating in a nurse-led diabetes management program in a public hospital in Lima, Peru. METHOD: This cross-sectional study included adult PLDM (N = 54). The instrument included demographic items and the Spanish versions of the social/vocational concern dimension of the Diabetes Quality of Life Questionnaire and the Reed's scale of spiritual perspective. RESULTS: There was an inverse relation between social support and spiritually practices (p = .020) and spiritual beliefs (p = .005). PLDM with 5 years or more in the program had significantly higher scores in social support (p = .020) and spiritual practices (p = .010). CONCLUSION: Spirituality and social support are important factors for managing PLDM. Nurse-led diabetes management programs with Latino participants should consider targeted spiritual and social support strategies to expand the holistic management. Future studies should explore the impact and effectiveness of spiritual and social support interventions on clinical outcomes.

Chemoprotective effects of Ulva lactuca (green seaweed) aqueous-ethanolic extract against subchronic exposure to benzo(a)pyrene by CYP1A1 inhibition in mice.

The protective effect of the supplementation with an aqueous-ethanolic extract obtained from Ulva lactuca (Delile) green seaweed on benzo[a] pyrene-induced damage in mice was evaluated. Animals were treated with oral doses of U. lactuca extract (100 and 400 mg/kg) for 9 weeks. They were exposed to 50 mg/kg of oral doses of benzo(a)pyrene starting from the second week and up to the fifth week. Groups treated with benzo(a)pyrene only (second to fifth weeks), sunflower oil (vehicle, 9 weeks), or U. lactuca extract (100 and 400 mg/kg, 9 weeks) were also included in the study. The treatment with 400 mg/kg of the extract ameliorated the oxidative damage, decreased IL-1ß and TNF-α levels, and favorably regulated the antioxidant defenses compared with benzo(a)pyrene-exposed group. The benzo(a)pyrene-induced DNA damage was also reduced, as it was evidenced by the lower micronucleus formation in U. lactuca extract-supplemented animals. The extract protected the hepatic tissue, and it reduced the liver activity/expression of CYP1A1. These results altogether suggested a chemoprotective effect of U. lactuca extract against benzo(a)pyrene-induced-toxicity in mice, probably associated with an inhibitory effect of carcinogen bioactivation.

Osteopathic Manipulative Treatment Including Specific Diaphragm Techniques Improves Pain and Disability in Chronic Nonspecific Low Back Pain: A Randomized Trial.

OBJECTIVE: To investigate the effects of an osteopathic manipulative treatment (OMT), which includes a diaphragm intervention compared to the same OMT with a sham diaphragm intervention in chronic nonspecific low back pain (NS-CLBP). DESIGN: Parallel group randomized controlled trial. SETTING: Private and institutional health centers. PARTICIPANTS: Participants (N=66) (18-60y) with a diagnosis of NS-CLBP lasting at least 3 months. INTERVENTIONS: Participants were randomized to receive either an OMT protocol including specific diaphragm techniques (n=33) or the same OMT protocol with a sham diaphragm intervention (n=33), conducted in 5 sessions provided during 4 weeks. MAIN OUTCOME MEASURES: The primary outcomes were pain (evaluated with the Short-Form McGill Pain Questionnaire [SF-MPQ] and the visual analog scale [VAS]) and disability (assessed with the Roland-Morris Questionnaire [RMQ] and the Oswestry Disability Index [ODI]). Secondary outcomes were fear-avoidance beliefs, level of anxiety and depression, and pain catastrophization. All outcome measures were evaluated at baseline, at week 4, and at week 12. RESULTS: A statistically significant reduction was observed in the experimental group compared to the sham group in all variables assessed at week 4 and at week 12 (SF-MPQ [mean difference -6.2; 95% confidence interval, -8.6 to -3.8]; VAS [mean difference -2.7; 95% confidence interval, -3.6 to -1.8]; RMQ [mean difference -3.8; 95% confidence interval, -5.4 to -2.2]; ODI [mean difference -10.6; 95% confidence interval, -14.9 to 6.3]). Moreover, improvements in pain and disability were clinically relevant. CONCLUSIONS: An OMT protocol that includes diaphragm techniques produces significant and clinically relevant improvements in pain and disability in patients with NS-CLBP compared to the same OMT protocol using sham diaphragm techniques.

Effects of Myofascial Release in Nonspecific Chronic Low Back Pain: A Randomized Clinical Trial.

STUDY DESIGN: Double-blind, randomized parallel sham-controlled trial with concealed allocation and intention-to treat analysis. OBJECTIVE: To investigate the effects of an isolate myofascial release (MFR) protocol on pain, disability, and fear-avoidance beliefs in patients with chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA: MFR is a form of manual medicine widely used by physiotherapists in the management of different musculoskeletal pathologies. Up to this moment, no previous studies have reported the effects of an isolated MFR treatment in patients with CLBP. METHODS: Fifty-four participants, with nonspecific CLBP, were randomized to MFR group (n = 27) receiving four sessions of myofascial treatment, each lasting 40 minutes, and to control group (n = 27) receiving a sham MFR. Variables studied were pain measured by means Short Form McGill Pain Questionnaire (SF-MPQ) and visual analog scale (VAS), disability measured with Roland Morris Questionnaire, and fear-avoidance beliefs measured with Fear-Avoidance Beliefs Questionnaire. RESULTS: Subjects receiving MFR displayed significant improvements in pain (SF-MPQ) (mean difference -7.8; 95% confidence interval [CI]: -14.5 to -1.1, P = 0.023) and sensory SF-MPQ subscale (mean difference -6.1; 95% CI: -10.8 to -1.5, P = 0.011) compared to the sham group, but no differences were found in VAS between groups. Disability and the Fear-Avoidance Beliefs Questionnaire score also displayed a significant decrease in the MFR group (P < 0.05) as compared to sham MFR. CONCLUSION: MFR therapy produced a significant improvement in both pain and disability. Because the minimal clinically important differences in pain and disability are, however, included in the 95% CI, we cannot know whether this improvement is clinically relevant. LEVEL OF EVIDENCE: 2.

Efecto a largo plazo del policosanol en la recuperación funcional de pacientes con ictus isquémico no cardioembólico: estudio de un año / Long-term eff ect of policosanol on the functional recovery of non-cardioembolic ischemic stroke patients: a one year study

Introducción. El ictus es una causa principal de mortalidad y discapacidad. El policosanol ha sido efi caz en modelos de isquemia cerebral. Este estudio investiga si el tratamiento a largo plazo con policosanol, añadido a la terapia con ácido acetilsalicílico (AAS), dentro de los 30 días posteriores a un ictus, es mejor que el placebo + AAS en la recuperación de los pacientes. Pacientes y métodos. Estudio aleatorizado, doble ciego, controlado con placebo. Se incluyeron 80 pacientes (edad media: 69 años) que sufrieron un ictus en los 30 días previos y con una puntuación de 2-4 en la escala de Rankin modifi cada(mRS). Se distribuyeron aleatoriamente en dos grupos y recibieron policosanol + AAS o placebo + AAS durante 12 meses. Resultados. El tratamiento con policosanol + AAS disminuyó signifi cativamente la puntuación en la mRS desde el primer control intermedio (1,5 meses). El efecto del tratamiento incluso mejoró con la terapia a largo plazo. El número de pacientes que alcanzaron valores de mRS menores o iguales a 1 fue superior en el grupo de policosanol + AAS (87,5%) que en el de placebo + AAS (0%). El tratamiento con policosanol + AAS aumentó signifi cativamente el índice de Barthel, disminuyó el colesterol LDL y aumentó el colesterol HDL frente a placebo + AAS. Conclusiones. El tratamiento a largo plazo (12 meses) con policosanol + AAS fue más efectivo que el tratamiento con placebo + AAS en la recuperación funcional de los pacientes después de sufrir un ictus isquémico no cardioembólico de moderada gravedad (AU)

Introduction. Stroke is a leading cause of mortality and disability. Policosanol has been eff ective in brain ischemia models. The aim of this study is to investigate whether policosanol, added to aspirin therapy within 30 days of stroke onset, is better than placebo + aspirine for the long-term recovery of non-cardioembolic ischemic stroke subjects. Patients and methods. Randomized, double-blind, placebo-controlled study. Eighty patients (mean age: 69 years) within 30 days of onset, with a modifi ed Rankin Scale score (mRS) 2 to 4, were included. They were randomized in two groups (policosanol + aspirine or placebo + aspirine) for 12 months. Results. Policosanol + aspirine decreased signifi cantly mean mRS from the fi rst interim check-up (1.5 months). The treatment even improved after long-term therapy. More policosanol + aspirin (87.5%) than placebo + aspirine (0%) patients achieved mRSs ≤ 1. Policosanol + aspirine increased signifi cantly Barthel Index, lowered LDL-cholesterol and increased HDL-cholesterol versus placebo + aspirin. Conclusions. Long-term (12 months) administration of policosanol + aspirin given after suff ering non-cardioembolic ischemic stroke was shown to be better than placebo + aspirin in improving functional outcomes when used among patients with non-cardioembolic ischemic stroke of moderate severity (AU)

Effects of a Combined Therapy With D-002 (Beeswax Alcohols) Plus D-003 (Sugarcane Wax Acids) on Osteoarthritis Symptoms.

Context • Nonsteroidal, anti-inflammatory drugs effectively relieve osteoarthritis (OA) symptoms but also induce adverse effects (AEs) that limit their long-term use, which drives a search for safer treatments. D-002, a mixture of beeswax alcohols, and D-003, a mixture of sugarcane wax acids, have been effective in experimental and clinical studies for patients with OA. Objective • The study intended to investigate the effects on OA symptoms of a combined therapy using D-002 and D-003 (D-002/D-003), which were administered for 6 wk. Design • The study was a randomized, double-blind, placebo-controlled trial. Setting • The study was conducted at the Surgical Medical Research Center in Havana, Cuba. Participants • Participants were patients with mild-to-moderate OA. Intervention • Participants were randomly assigned to 1 of 4 groups-(1) a control group, which received a placebo; (2) the D-002 group (intervention group), which received 50 mg/d of D-002; (3) the D-003 group (intervention group), which received 10 mg/d of D-003; or (4) the D-002/D-003 group (intervention group), which received a combined therapy of 50 mg/d of D-002 plus 10 mg/d of D-003. The control group received tablets that were indistinguishable in appearance from the D-002 and D-003 tablets and had a similar composition, except that the active ingredients were replaced by lactose. The groups took the medications once per day for 6 wk. Outcome Measures • Symptoms were assessed using the Western Ontario and McMaster Individual Osteoarthritis Index (WOMAC) and a visual analogue scale (VAS). The primary outcome was the reduction in the total WOMAC score. The subscale scores on the WOMAC for pain, stiffness, and physical function, the VAS scores, and the use of rescue medications were secondary outcomes. Results • Of the 120 enrolled participants, 116 completed the study. The treatments with D-002, D-003, and D-002/D-003 reduced the mean total WOMAC scores significantly from baseline to postintervention, by 75.1%, 72.8%, and 91.2%, respectively. Compared with the placebo, the treatments decreased the mean WOMAC scores for pain, joint stiffness, and physical function significantly. The VAS scores significantly decreased, showing a 71.4%, a 66.9%, and an 84.7% reduction for the D-002, D-003, and D-002/D-003 groups, respectively. All the reductions were significant from the first week and were enhanced during the trial. The D-002/D-003 treatment was more effective in improving all of the scores than either monotherapy. With respect to rescue medications, 3/30, 2/30, and 2/30 used the medications in the D-002, D-003, and D-002/D-003 groups, respectively, vs 17/30 in the control group. The treatments were well tolerated. Conclusions • Administered for 6 wk, 50 mg/d of D-002 and 10 mg/d of D-003 ameliorated OA symptoms, but the combined therapy, D-002/D-003, was more effective than either monotherapy. All treatments were well tolerated.

Effects of D-002, a mixture of high molecular weight beeswax alcohols, on patients with nonalcoholic fatty liver disease.

BACKGROUND/AIMS: Nonalcoholic fatty liver disease (NAFLD) is intimately related to insulin resistance and ranges from a benign course to liver fibrosis and cirrhosis. NAFLD management mainly involves dietary modification and weight loss. Although no fully successful pharmacological intervention is available, alternative therapies to treat NAFLD have shown promising results. Experimental studies have shown that D-002, a mixture of beeswax alcohols with antioxidant effects, is hepatoprotective. The aim of this study was to investigate the efficacy and safety of D-002 in patients with NALFD. METHODS: Fifty patients with NAFLD were randomized to receive a placebo or D-002 (100 mg/day) for 24 weeks. The primary endpoint was a significant ultrasonography-detected reduction of liver fat infiltration versus a placebo. Secondary endpoints were decreases in the homeostatic model assessment (HOMA) index, insulin levels, serum liver enzymes, increases in plasma total antioxidant status (TAS) and improved clinical symptoms versus the placebo recipients. RESULTS: At randomization, all indicators were comparable in both groups. At study completion, seven (28.0%) D-002-patients, but none of the placebo recipients, exhibited a normal liver echo pattern on ultrasonography (p < 0.01). Also, D-002 significantly reduced (p < 0.01 vs. baseline and placebo) the HOMA index and insulin levels and increased the TAS, but did not affect other parameters. The proportion of D-002-patients (12/25, 48.0%) showing symptom improvement was higher (p < 0.001) than that of the placebo group (1/25, 4.0%). The treatment was safe and well tolerated. Three patients in each group withdrew from the study. CONCLUSIONS: D-002 (100 mg/day) improved ultrasonographic findings, indicators of insulin resistance, plasma TAS and clinical evolution on NAFLD patients. Further studies, however, are needed to confirm these results.

Evaluation of anti-inflammatory and antinociceptive effects of D-002 (beeswax alcohols).

D-002, a mixture of six higher aliphatic alcohols purified from beeswax, displayed anti-inflammatory effects in carrageenan-induced pleurisy and cotton pellet granuloma in rats. The aim of the present study was to confirm the anti-inflammatory properties of D-002 and to explore its potential analgesic effects. Xylene-induced mouse ear oedema was used to assess the anti-inflammatory effect, acetic acid-induced writhing and hot plate responses for the analgesic activity, and the open field and horizontal rotarod tests for motor performance. For anti-inflammatory tests, mice were randomised into a negative vehicle control and five xylene-treated groups: the vehicle, D-002 (25, 50 and 200 mg/kg) and indomethacin 1 mg/kg (reference drug). Treatments were given for 15 days. Effects on oedema formation and myeloperoxidase (MPO) activity were tested. For analgesia and motor performance tests, mice were randomised into a vehicle control and D-002-treated groups (25, 50 and 200 mg/kg). Two sets of experiments were done, which included acute and repeat (15 days) dosing. D-002 (25, 50 and 200 mg/kg) significantly decreased xylene-induced ear oedema (44.7, 60.8 and 76.4%, respectively) and the increase of MPO activity induced by xylene (38.0, 47.0 and 57.0%, respectively), while indomethacin significantly inhibited xylene-induced oedema (59.9%) and MPO activity (57.5%). Single and repeat doses of D-002 (25, 50 and 200 mg/kg) decreased the acetic acid-induced writhing responses by 21.2, 28.2 and 40.1%, for the single doses; 25.2, 35.1 and 43.2%, respectively, for the repeat doses, but did not affect the hot plate, open field and rotarod behaviours. Aspirin 100 mg/kg significantly decreased acetic acid-induced abdominal constrictions and morphine (5 mg/kg) significantly increased the latency of the hot plate response. This study confirmed the anti-inflammatory effects of D-002 and demonstrated its analgesic effects on the acetic acid-induced writhing, but not on the hot plate response, which suggests that the antinociceptive effects of D-002 could be related to its anti-inflammatory activity.

Metabolomic approach to the nutraceutical effect of rosemary extract plus Ω-3 PUFAs in diabetic children with capillary electrophoresis.

Type 1 diabetes mellitus is a major endocrine disorder, affecting approximately 5% of the world's population. It not only leads to hyperglycaemia but also causes many complications, and numerous studies have demonstrated that oxidative stress contributes to these complications. As a new strategy to improve the oxidative damage in diabetes, interest has grown in the usage of natural antioxidants, even more in the long term. Among them, Rosmarinus officinalis (rosemary) has been widely accepted as one of the species with the highest antioxidant activity. In addition, omega-3 polyunsaturated fatty acids were efficient in delaying and decreasing cardiovascular risk factors associated with diabetes. Type 1 diabetic children and the corresponding controls were enrolled in the assay. The aim was evaluating the effect of a special additive containing rosemary extract, vitamin E and PUFAs added to their standard diet through the meat. In the analytical point of view, a metabolomic approach with CE-UV was used to detect possible differences in urine of diabetic children as compared to controls. After the application of the appropriate multivariate statistical tools, clear differences could be observed between treated and non-treated diabetic children and some of the metabolites associated could be identified. This was specially challenging as most of the clinical biochemical parameters measured by target analysis showed no differences between the groups.

Antioxidant effects of D-004, a lipid extract from the Roystonea regia fruit, on the plasma of healthy men

The aim of this study was to conduct a randomized, double-blind and placebo-controlled study to investigate the effects of D-004, a lipid extract of the Roystonea regia fruit that prevents testosterone- and phenylepinephrine-induced prostate hyperplasia in rodents, on plasma oxidative markers in healthy men. We enrolled male volunteers (20–55 years) in good health and without lower urinary tract symptoms. Thirty-four eligible participants were randomized to placebo or D-004 (320 mg) capsules administered daily for 6 weeks. An interim check-up and a final visit were conducted after 3 and 6 weeks of therapy, respectively. Physical examinations were performed at each visit, and laboratory tests were performed at baseline and at treatment completion. Oxidative variables included plasma malondialdehyde (MDA), total hydroxyperoxides (TOH), sulphydryl (SH) groups and total antioxidant status (TAS). We assessed treatment compliance and addressed adverse experiences (AEs) at weeks 3 and 6. At week 6, with D-004, the mean reductions of plasma MDA (26.7 percent), TOH (18.8 percent) and SH groups (31.6 percent), and the mean increase of TAS (35.3 percent) were significantly different from those of placebo (P < 0.001 for plasma TAS, P < 0.0001 for all other comparisons). D-004 did not differ from the placebo in safety indicators. There were two withdrawals (both in the D-004 group), with one due to dyspepsia (the only AE during the trial). In conclusion, D-004 displayed antioxidant effects on plasma oxidative markers in healthy men, which was consistent with findings from laboratory experimental studies(AU)

Antioxidant effects of D-004, a lipid extract from the Roystonea regia fruit, on the plasma of healthy men.

The aim of this study was to conduct a randomized, double-blind and placebo-controlled study to investigate the effects of D-004, a lipid extract of the Roystonea regia fruit that prevents testosterone- and phenylepinephrine-induced prostate hyperplasia in rodents, on plasma oxidative markers in healthy men. We enrolled male volunteers (20-55 years) in good health and without lower urinary tract symptoms. Thirty-four eligible participants were randomized to placebo or D-004 (320 mg) capsules administered daily for 6 weeks. An interim check-up and a final visit were conducted after 3 and 6 weeks of therapy, respectively. Physical examinations were performed at each visit, and laboratory tests were performed at baseline and at treatment completion. Oxidative variables included plasma malondialdehyde (MDA), total hydroxyperoxides (TOH), sulphydryl (SH) groups and total antioxidant status (TAS). We assessed treatment compliance and addressed adverse experiences (AEs) at weeks 3 and 6. At week 6, with D-004, the mean reductions of plasma MDA (26.7%), TOH (18.8%) and SH groups (31.6%), and the mean increase of TAS (35.3%) were significantly different from those of placebo (P<0.001 for plasma TAS, P<0.0001 for all other comparisons). D-004 did not differ from the placebo in safety indicators. There were two withdrawals (both in the D-004 group), with one due to dyspepsia (the only AE during the trial). In conclusion, D-004 displayed antioxidant effects on plasma oxidative markers in healthy men, which was consistent with findings from laboratory experimental studies.

Manejo del sangrado en cirugía ortognática / Handling bleeding in orthognathic surgery

La magnitud y el control del sangrado, junto al requerimiento de transfusión, han sido temas muy controvertidos en la cirugía ortognática. En la literatura se menciona el uso de técnicas y criterios disímiles y contradictorios. Hemos querido actualizar los criterios sobre el manejo del sangrado en la cirugía maxilofacial en base a nuestra experiencia con el uso de técnicas quirúrgicas y anestésicas actuales. Se presenta aquí una revisión crítica de las publicaciones sustentada por la experiencia clínica del equipo quirúrgico. Se discuten temas relacionados con el sangrado intraoperatorio tales como la predonación sanguínea, la reducción del sangrado mediante técnicas de hipotensión controlada, y el uso de vasoconstrictores o antifibrinolíticos junto a los fármacos anestésicos. Se realizan recomendaciones en base a nuestra experiencia clínica. La presente revisión concluye que con las técnicas actuales, como la anestesia hipotensiva y la anestesia basada en la analgesia simpaticolítica, se logra una mínima pérdida de sangre durante la cirugía ortognática. Estas técnicas prácticamente eliminan la necesidad de transfusiones sanguíneas, predonación y el uso rutinario de antifibrinolíticos, y las posibles complicaciones que estos conllevan.

The magnitude and management of blood loss, as well as the necessity of transfusion have been controversial themes in orthognathic surgery. Different and contradictory techniques and criteria have been used and exposed in the current literature. The aim of this study is to bring up to date the criteria concerning management of blood loss in maxillofacial surgery, based on our clinical experience with recent surgical and anesthetic techniques. A critical revision of the literature is exposed, according to the experience of the surgical team of the Maxillofacial department in. Themes related to intraoperative blood loss, preoperative autologous blood donation, drugs used in the anesthetic technique, reduction of blood loss with hypotensive anesthesia, the use of epinephrine and antifibrinolytic agents are discussed. Finally we present some recommendations based on our experience. This study shows that blood loss during orthognathic surgery is minimal with techniques such as hypotensive anesthesia and the analgesic sympathicolytic based anesthesia. These techniques practically eliminate the necessity of transfusion, preoperative autologous donation, the use of habitual antifibrinolytic agents and its complications.

A intensidade e o controle do sangramento, e a necessidade de transfusao, sao assuntos muito controvertidos na cirurgia ortognática. Na literatura se menciona o uso de técnicas e critérios diferentes e contraditórios. Atualizamos os princípios do manejo do sangramento na cirurgia maxilofacial em base a nossa experiencia no uso das técnicas cirúrgicas e anestésicas atuais. Fazemos uma revisao crítica das publicaçoes sustentada pela experiencia clínica da equipe de cirurgia. Sao discutidos temas relacionados com o sangramento intra-operatório, tais como a pre-doaçao de sangue, a reduçao do sangramento mediante técnicas de hipotensao controlada, e o uso de vasoconstritores ou antifibrinolíticos junto aos fármacos anestésicos. Fazemos recomendaçoes em base a nossa experiencia clínica. Conclui-se que com as técnicas atuais, como a anestesia hipotensiva e a anestesia baseada na analgesia simpaticolítica, é possível reduzir ao mínimo a perda de sangre durante a círurgia ortognática. Estas técnicas praticamente eliminam a necessidade de transfusoes sanguíneas, a pré-doaçao e o uso rotineiro de antifibrinolíticos, e as possíveis conseqüentes complicaçoes.

Mechanical unfolding pathways of the enhanced yellow fluorescent protein revealed by single molecule force spectroscopy.

We used single molecule force spectroscopy to characterize the mechanical stability of the enhanced yellow fluorescent protein (EYFP) (a mutant form of the green fluorescent protein (GFP)) and two of its circularly permutated variants. In all three constructs, we found two main unfolding peaks; the first corresponds to a transition state placed close to the termini and the second to a transition state placed halfway through the molecule. We attribute the second transition state to the shear rupture of the beta1- and beta6-strands, which we verified by introducing a point mutation in this region. Although both unfolding peaks were observed in all three EYFP variants, their relative frequency of occurrence varied. Our results demonstrated that the mechanical unfolding pathways in EYFP could be deciphered through the use of circular permutation.

Effect of liquefied petroleum gas on ozone formation in Guadalajara and Mexico City.

Leakages of liquefied petroleum gas (LPG) are suspected to contribute greatly to ozone (O3) formation in Mexico City. We tested such a hypothesis by outdoor captive-air irradiation (CAI) experiments in the two largest Mexican metropolitan areas: Guadalajara (GMA) in 1997 and Mexico City (MCMA) in 2000. O3 was monitored in each city for 20 days (8:00 a.m.-6:00 p.m.) in smog chambers containing unaltered morning air or morning air enriched with either commercial LPG or LPG synthetic mixture 60/40 (propane and butane). Tested additions of both components were 35% (by volume) in GMA and 60% (by volume) in MCMA. The addition effects on O3 (max) were compared with effects from diluting LPG components or total nonmethane hydrocarbons (tNMHCs) by 50%. Diluting tNMHCs had the greatest absolute effect at both cities: it lowered O3 (max) by 24% in GMA and 55% in MCMA. Adding commercial LPG increased O3 (max) by 6% in GMA and 28% in MCMA; whereas adding LPG synthetic mixture 60/40 caused a similar increase in O3 (max), 4 and 21% in GMA and MCMA, respectively. Compared with dilution of tNMHCs, dilution of LPG-associated compounds had a smaller decreasing effect on O3 (max), only 4% in GMA and 15% in MCMA. These results show that commercial LPG and LPG synthetic mixture 60/40 affect O3 formation to a lesser extent than estimated previously.