Correlation between urinary KIM-1 and kidney protein expression of p-ERK following damage in rats exposed to gentamicin or lead acetate.

Kidney injury molecule-1 (KIM-1) is a membrane receptor upregulated in the proximal tubule cells following various types of kidney injuries. Notably, studies have suggested a correlation between KIM-1 expression and extracellular signal-regulated kinase (ERK) activation. In this study, we aimed to investigate the association between the kidney overexpression pattern of cytoplasmic phosphorylated-ERK (p-ERK) protein and increased urinary KIM-1 levels in rats exposed to gentamicin or lead acetate, both at the end of toxic exposure and after a 4-week recovery period. Although other proteins were evaluated, only kidney overexpression of cytoplasmic p-ERK protein correlated with increased urinary KIM-1 levels. For both toxic substances, the increased urinary KIM-1 levels corresponded with kidney inflammation. Our results suggest that KIM-1 and p-ERK share a common mechanism in kidney injury mediated by both toxic substances that induce proximal tubule damage.

Oral Administration of Microencapsulated B. Longum BAA-999 and Lycopene Modulates IGF-1/IGF-1R/IGFBP3 Protein Expressions in a Colorectal Murine Model.

The Insulin-like growth factor-I/Insulin-like growth factor-I receptor (IGF-1/IGF-1R) system is a major determinant in colorectal cancer (CRC) pathogenesis. Probiotics (Bifidobacterium longum, BF) and lycopene (LYC) have been individually researched for their beneficial effects in the prevention of CRC. However, the effect of a combined treatment of microencapsulated BF and LYC on IGF-1/IGF-1R/IGFBPs (Insulin-like growth factor-binding proteins) expression in an azoxymethane (AOM)-dextran sulfate sodium (DSS)-induced CRC model have not been demonstrated. BF was microencapsulated by the spray drying technique, with high viability, and daily gavaged with LYC for 16 weeks to CD-1 mice in an AOM-DSS model. The results indicated that BF- and BF + LYC-treated groups had significantly lower inflammation grade, tumor incidence (13-38%) and adenocarcinoma (13-14%) incidence compared to the AOM + DSS group (80%), whereas LYC treatment only protected against inflammation grade and incidence. Caecal, colonic and fecal pH and ß-glucuronidase (ß-GA) values were significantly normalized by BF and LYC. Similarly, BF and BF + LYC treatments significantly reduced both the positive rate and expression grade of IGF-1 and IGF-1R proteins and normalized Insulin-like growth factor-binding protein-3 (IGFBP3) expression. Based on intestinal parameters related to the specific colon carcinogenesis in an AOM-DSS-induced model, LYC and microencapsulated BF supplementation resulted in a significant chemopreventive potential through the modulation of IGF-1/IGF-1R system.

Lycopene Improves Diet-Mediated Recuperation in Rat Model of Nonalcoholic Fatty Liver Disease.

The aim of the present study was to evaluate the synergic effect of lycopene (LYC) treatment with a dietary control in a nonalcoholic fatty liver disease (NAFLD) model induced with a high-fat diet (HFD). Sprague-Dawley rats were fed during 4 weeks with a normal diet (ND·4w) or an HFD (HFD·4w) to produce an NAFLD model. Then, rats from the ND·4w group continued during 4 weeks with the same diet (ND·8w), and rats from HFD were fed during 4 weeks with an ND (HFD·4w+ND·4w) or an ND plus LYC (HFD·4w+ND+LYC·4w). LYC (20 mg/kg) was administered daily by gavage. ND and ND+LYC diets partially reverted the following alterations due to HFD: liver weight, serum low-density lipoproteins (LDL), hepatic total cholesterol (TC), and catalytic activity of hepatic superoxide dismutase, catalase, and glutathione peroxidase, as well as macroscopic and microscopic images of livers. A higher recuperation to reach normality was obtained with ND+LYC in: liver weight, hepatic TC, serum LDL, and, in some instances, macroscopic and microscopic images of livers. Failures to recovery with both NDs were observed for malondialdehyde level and serum aspartate aminotransferase activity. Taken together, the results from this study suggest the potentially protective role of LYC against NAFLD; however, more clinical trials are needed to support this idea.

[Bilateral and synchronous testicular teratoma: a case report and literature review]. / Teratoma testicular bilateral sincrónico: reporte de un caso y revisión de la literatura.

BACKGROUND: Testicular germ-cell carcinoma is the most frequent neoplasm in males aged 15 to 35 years old. It is bilateral in 2% to 3%, and synchronous in 20% to 25% of the cases. CLINICAL CASE: The case is presented of a 19 year-old male, with abdominal pain. Physical examination revealed abdominal mass in the umbilical region, and the computed tomography scan showed a retroperitoneal tumour, with α-fetoprotein, lactate dehydrogenase, and human chorionic gonadotropin above limits. Testicular ultrasound showed bilateral lesions. Exploratory laparotomy was performed, identifying an unresectable retroperitoneal tumour. Biopsies were taken, reporting mixed germ cell tumour composed of choriocarcinoma and embryonal carcinoma. Six cycles of chemotherapy were given, based on bleomycin, etoposide and cisplatin, with partial tumour response. Later on, the patient underwent bilateral radical orchiectomy, with pathology reporting a synchronous bilateral testicular teratoma. A second line of chemotherapy was given, based on vincristine, etoposide, ifosfamide and cisplatinum. Nevertheless, the disease progressed, with metastatic dissemination and the patient died. DISCUSSION: Germ cells tumours can present in primary extra-gonadal locations. It is difficult to distinguish a retroperitoneum primary germ cell tumour from metastatic disease of a clinically undetected gonadal tumour or one that has regressed, like the situation described in the case presented. CONCLUSIONS: Ninety percent of patients diagnosed with germ cell tumours can be cured. However, delay in diagnosis correlates with an advanced clinical stage and poor prognosis.

Protective effects of dietary avocado oil on impaired electron transport chain function and exacerbated oxidative stress in liver mitochondria from diabetic rats.

Electron transport chain (ETC) dysfunction, excessive ROS generation and lipid peroxidation are hallmarks of mitochondrial injury in the diabetic liver, with these alterations also playing a role in the development of non-alcoholic fatty liver disease (NAFLD). Enhanced mitochondrial sensitivity to lipid peroxidation during diabetes has been also associated to augmented content of C22:6 in membrane phospholipids. Thus, we aimed to test whether avocado oil, a rich source of C18:1 and antioxidants, attenuates the deleterious effects of diabetes on oxidative status of liver mitochondria by decreasing unsaturation of acyl chains of membrane lipids and/or by improving ETC functionality and decreasing ROS generation. Streptozocin-induced diabetes elicited a noticeable increase in the content of C22:6, leading to augmented mitochondrial peroxidizability index and higher levels of lipid peroxidation. Mitochondrial respiration and complex I activity were impaired in diabetic rats with a concomitant increase in ROS generation using a complex I substrate. This was associated to a more oxidized state of glutathione, All these alterations were prevented by avocado oil except by the changes in mitochondrial fatty acid composition. Avocado oil did not prevented hyperglycemia and polyphagia although did normalized hyperlipidemia. Neither diabetes nor avocado oil induced steatosis. These results suggest that avocado oil improves mitochondrial ETC function by attenuating the deleterious effects of oxidative stress in the liver of diabetic rats independently of a hypoglycemic effect or by modifying the fatty acid composition of mitochondrial membranes. These findings might have also significant implications in the progression of NAFLD in experimental models of steatosis.

Salicylic acid elicitation during cultivation of the peppermint plant improves anti-diabetic effects of its infusions.

Peppermint (Mentha piperita) infusions represent an important source of bioactive compounds with health benefits, which can be enhanced by applying salicylic acid (SA) during plant cultivation. The aim of this study was to evaluate the effect of SA (0, 0.5 and 2 mM) during peppermint cultivation on the chemical profile of saponins and alkaloids, as well as the anti-diabetic properties of the resulting infusions. The results showed that a 2 mM SA treatment significantly improved the chemical profiles of the infusions. Furthermore, the administration of 2 mM SA-treated peppermint infusions for 4 weeks to a high-fat diet/streptozotocin-induced diabetic rats decreased serum glucose levels (up to 25%) and increased serum insulin levels (up to 75%) as compared with the diabetic control. This can be related to the observed protection on pancreatic ß-cells. Furthermore, 0.5 and 2 mM SA-treated peppermint infusions decreased LDL (24 and 47%, respectively) and increased HDL levels (18 and 37%, respectively). In addition, all groups treated with peppermint infusions had lower serum and liver triglyceride contents, where 2 mM SA peppermint infusion showed the highest effect (44% and 56%, respectively). This is probably caused by its higher capacity to inhibit pancreatic lipase activity and lipid absorption. Moreover, SA-treated peppermint infusions improved the steatosis score in diabetic rat liver and decreased serum transaminase levels, probably as a result of the increase in steroidal saponins and alkaloids, such as trigonellin. Therefore, the application of 2 mM SA during cultivation of peppermint could be used to improve the anti-diabetic properties of peppermint infusions.

Antioxidant, anti-inflammatory and anticarcinogenic activities of edible red oak (Quercus spp.) infusions in rat colon carcinogenesis induced by 1,2-dimethylhydrazine.

Red oak (Quercus spp.) leaves are traditionally used as food in Mexico, and some of their infusions have potential anticarcinogenic and anti-inflammatory effects; however, these properties have not yet been scientifically tested. The aim of this work was to explore the anti-inflammatory activity in HT-29 cells and anticarcinogenic effect in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis of red oak infusions. Quercus infusions were prepared and administered as the sole source of drink to male Sprague-Dawley rats (1% w/v) for the entire 26-week experimental period. On week 4, rats received 8 subcutaneous injections of DMH (21 mg/kg body weight) once a week. The results showed that mean tumor (0.9 ± 0.2 vs. 2.6 ± 0.3) and multiplicity (1.2 ± 0.1 vs. 2.0 ± 0.23), and ß-catenin protein level (2.2-fold) in adenocarcinomas were significantly lower in Quercus sideroxyla-treated group compared with DMH group. By contrast, Quercus durifolia and Quercus eduardii infusions had no protective effect. Additionally, the experiments in HT-29 cells confirmed that Q. sideroxyla infusion effectively decreased the levels of the inflammatory markers COX-2 and IL-8 by modulating the expression of NF-κB. These results highlight some of the molecular mechanisms related to the chemopreventive effect of Q. sideroxyla infusion and its potential value as a source of bioactive compounds.

Tolerability assessment of a lectin fraction from Tepary bean seeds (Phaseolus acutifolius) orally administered to rats.

Our previous studies have shown that a lectin rich fraction (TBLF) extracted from Tepary bean seeds differentially inhibits cancer cells proliferation in vitro. Before testing the in vivo anticancer effect, the acute and subchronic toxicological assays in rats were conducted, where an oral dose of 50 mg/body weight kg was determined as the NOAEL. This study evaluated the resistance to digestion and complete blood count (CBC) after 24 h of the orally administered 50 mg/kg TBLF. The digestion resistance test showed lectins activity retention after 72 h and the CBC study showed a high level of eosinophils, suggesting an allergic-like response. Tolerability was assayed after 6 weeks of treatment by dosing with an intragastric cannula every third day per week. It was observed a transient reduction in food intake and body weight in the first weeks, resulting in body weight gain reduction of 10% respect to the control group at the end of the study. Additionally, organs weight, histopathological analysis and blood markers for nutritional status and for liver, pancreas and renal function were not affected. Our results suggest that 50 mg/kg TBLF administered by oral route, exhibit no toxicity in rats and it was well tolerated. Further studies will focus on long-term studies.

[Ultrasound diagnosis of an abdominal aortic aneurysm in a 52 year old woman]. / Aneurisma de aorta abdominal en mujer de 52 años. Diagnóstico ecográfico.

The abdominal aortic aneurysm (AAA) is defined as increasing the diameter of the aorta in more than 50 % of its original size and the infra-renal location is the most common (90 %). AAA disease mainly affects older men and white smokers, and has a male: female ratio of 4:1, as well the diagnosis is rare in women under age 55. Aneurysm rupture is the most common complication and cause of death in the general population, its etiology is unclear, but is commonly associated with atherosclerosis. The AAA do not exhibit rupture and it is usually asymptomatic diagnosed incidentally, however, as the aneurysm grows, appears symptoms such as back pain, abdominal or groin pain, well as palpation of a pulse mass on umbilical and supra-umbilical region. Imaging study such as ultrasound and CT scan are the mainstay of diagnosis. We present a case of 52 years old patient with no history related to the diagnosis, who presented sudden and severe abdominal pain. She was admitted to the emergency room with a diagnosis of acute cholecystitis vs. acute pancreatitis. After ultrasound and CT studies, the diagnosis was a complicated abdominal aortic aneurysm.

Association between the Xba I polymorphism of APOB gene and plasma lipid level in Mexican patients with coronary artery disease.

Some studies, that consider polymorphisms of the apolipoprotein B (APOB) gene as risk factors for coronary artery disease (CAD), have reported discordant results. The aim of the present study was to search for associations between plasma lipid profiles with the DNA Xba I polymorphism of the APOB gene in CAD patients diagnosed by angiography (CAD+). In the present study we compared 114 Mexican patients (80 men and 34 women) with CAD+ and 132 control patients (59 men and 73 women) without evidence of ischemia or arterial damage (CAD-). The frequency of X+/X+ genotype of Xba I polymorphism, in CAD+ group, was 23% (26/114) compared with 8% (11/132) in the CAD- (OR 3.25, p = 0.002). The patients with X+/X+ for the Xba I genotype APOB gene had higher concentration of triglycerides (TG) and VLDL in plasma than CAD- (p< 0.05). The genotype X+/X+ in the CAD had an effect increasing the TG and VLDL plasma levels when compared with individuals with X-/X- and X-/X+ genotypes. The present study indicated that the X+X+ genotype of Xba I polymorphism is associated with CAD+ patients and high plasma levels of TG and VLDL, in the Mexican population.

[Secondary Raynaud's syndrome: skin blood flow decrease between the ischemic episodes and prolongation of the vasoconstriction during the respiratory maneuvers]. / Síndrome de Raynaud secundario: disminución del flujo sanguíneo de la piel entre los episodios isquémicos y prolongación de la vasoconstricción con las maniobras respiratorias.

UNLABELLED: The Raynaud's syndrome is an episodic skin ischemia manifested by pallor, cyanosis and erythema of the fingers in response to cold or emotional stress. The exact pathophysiology is unknown but it has been hypothetised that may be due to an autonomic alteration in the sympathetic innervation of skin blood vessels. OBJECTIVE: To study the changes of heart rate and skin blood flow (SBF) in healthy subjects and in patients with secondary Raynaud's syndrome during different respiratory maneuvers: 1. spontaneous respiration; 2. rhythmic respirations (RR), 3. sudden inspirations (SI), and 4. Valsalva maneuver (VM). METHODS: We studied 22 healthy subjects and 22 patients with secondary Raynaud's syndrome. The variables measured were: 1) RR intervals; 2) amplitudes of SBF; 3) percentage of decrease of SBF; 4) latency of the maximum decrease of SBF. RESULTS: In all patients with secondary Raynaud's syndrome the SBF was decreased basally during spontaneous rations and during all respiratory maneuvers (p < 0.001). The mean latency of recovery of the SBF was prolonged during sudden deep inspiration. The patients with Raynaud also had significant basal tachycardia at rest (p < 0.003). CONCLUSIONS: The basal skin blood flow during spontaneous respirations and in asymptomatic periods is decreased in patients with Raynaud's syndrome; this may be related to endothelial arterioral damage. The SBF was also significantly decreased dynamically during sudden inspirations (SI), rhythmic breathing (RR) and Valsalva maneuver (VM). This dynamic change suggests sympathetic hyperactivity.

Síndrome de Raynaud secundario: disminución del flujo sanguíneo de la piel entre los episodios isquémicos y prolongación de la vasoconstricción con las maniobras respiratorias / Secondary Raynaud's syndrome: skin blood flow decrease between the ischemic episodes and prolongation of the vasoconstriction during the respiratory maneuvers

El síndrome de Raynaud se caracteriza por isquemia cutánea digital episódica, manifestada por palidez, cianosis y rubor de los dedos de manos y pies expuestos al frío o cuando el paciente está sujeto a un estrés emocional. No se conoce el mecanismo fisiopatológico exacto; la hipótesis más invocada es una alteración autonómica en la inervación simpática de los vasos sanguíneos de la piel. Objetivo: Estudiar los cambios de la frecuencia cardíaca y el flujo sanguíneo de la piel (FSP) en sujetos sanos y en pacientes con síndrome de Raynaud durante las siguientes condiciones: 1. respiración espontánea (RE), 2. respiración rítmica (RR), 3. inspiración profunda repentina (IPR), 4. maniobra de Valsalva (MV). Método: Se estudiaron 22 sujetos sanos y 22 pacientes con síndrome de Raynaud secundario. Las variables medidas fueron: 1. intervalo R-R; 2. amplitud de FSP; 3. porcentaje de disminución de FSP; 4. latencia de la máxima disminución del FSP. Resultados: Los pacientes con síndrome de Raynaud presentaron mayor taquicardia basal. La amplitud del FSP se encontró disminuido durante la respiración espontánea y durante las maniobras respiratorias (P < 0.001). La vasoconstricción estuvo prolongada ya que la latencia promedio de recuperación del FSP estuvo prolongada en IPR y MV en comparación de los sujetos controles. Conclusión: La amplitud del FSP basal está disminuida en los pacientes con síndrome de Raynaud, durante períodos asintomáticos; esto sugiere daño endotelial. También se encontró disminuido con las diversas maniobras respiratorias (RR, IPR y MV). Este cambio dinámico sugiere hiperactividad simpática hacia los vasos sanguíneos de la piel.

The Raynaud's syndrome is an episodic skin ischemia manifested by pallor, cyanosis and erythema of the fingers in response to cold or emotional stress. The exact pathophysiology is unknown but it has been hypothetised that may be due to an autonomic alteration in the sympathetic innervation of skin blood vessels. Objective: To study the changes of heart rate and skin bloodflow (SBF) in healthy subjects and in patients with secondary Raynaud's syndrome during different respiratory maneuvers: 1. spontaneous respiration; 2. rhythmic respirations (RR), 3. sudden inspirations (SI), and 4. Valsalva maneuver (VM). Methods: We studied 22 healthy subjects and 22 patients with secondary Raynaud's syndrome. The variables measured were: 1) RR intervals; 2) amplitudes of SBF; 3) percentage of decrease of SBF; 4) latency of the maximum decrease of SBF. Results: In all patients with secondary Raynaud's syndrome the SBF was decreased basally during spontaneous respirations and during all respiratory maneuvers (p < 0.001). The mean latency of recovery of the SBF was prolonged during sudden deep inspiration. The patients with Raynaud also had significant basal tachycardia at rest (p < 0.003). Conclusions: The basal skin blood flow during spontaneous respirations and in asymptomatic periods is decreased in patients with Raynaud's syndrome; this may be related to endothelial arterioral damage. The SBF was also significantly decreased dynamically during sudde3n inspirations (SI), rhythmic breathing (RR) and Valsalva maneuver (VM). This dynamic change suggests sympathetic hyperactivity.

[Response of skin blood flow to several respiratory maneuvers in healthy subjects]. / Respuesta del flujo sanguíneo de la piel con diferentes maniobras respiratorias en sujetos sanos.

INTRODUCTION: In the diagnosis of autonomic disturbances, the variability of skin blood flow (SBF) and the sympathetic skin response (SSR) in response to several respiratory maneuvers are not routinely studied. OBJECTIVE: We sought to standardize the method of SBF variability and SSR in healthy subjects during four respiratory maneuvers: 1) spontaneous breathing (SB); 2) rhythmic breathing at a rate of 6 per minute (RB); 3) sudden deep inspiration (SDI); 4) Valsalva maneuver (VM). SUBJECTS, MATERIAL AND METHOD: We studied 30 healthy subjects with a mean age of 32 years, 60% were men and 40% women. We used a photopletysmograph in the finger pad to measure SBF and surface electrodes on the palms of the hand to register the SSR. We also recorded the ECG and the respiratory movements. The variables were: 1) amplitude of SBF; 2) latency and duration of SSR; 3) percentage of decrease of the SBF during the maneuvers compared with the basal flow. RESULTS: During spontaneous breathing there was no respiratory modulation of the SBF and during RB the SBF was modulated with respiration. With SDI there was a 60% decrease of the SBF. VM induced a larger SBF decrease of 72 per cent. A significant statistical difference was revealed when we compared the decrease of SBF basal breathing with SDI and VM (P < 0.001). The difference was also significant between the SDI and VM (P < 0.001). The SBF decrease recovered more slowly after the SDI (beat 7) than after the VM (veat 6). The SBF decrease was more pronounced in magnitude during the VM. The latency of the SSR appears spontaneously and at random in 57% of subjects during normal breathing but it appeared consistently during RB, SDI, and VM. The latency of SSR was longer during SB (1.7 +/- 0.7 s), RB (1.6 +/- 0.7 s) than SDI (0.7 +/- 0.5 s) and VM (0.8 +/- 0.9 s) (P > 0.050). Duration of the SSR was significantly longer in the SDI (around 7.8 +/- 2.4 s) and during the VM (8 +/- 2.5 s) as compared to normal breathing (6.3 +/- 1.0 s) and RB (6.4 +/- 1.5 s) (P < 0.009). CONCLUSIONS: SB and RB induce periodic modulation of sympathetic activity to skin blood vessels and sweat glands. SDI and VM produced a much greater activation of sympathetic skin activity than SB and RB. The increased SSR duration and the profound SBF decrease with SDI and VM as compared to SB or RB are consistent with this hypothesis. The latency of the SSR is much shorter with SDI and VM than with SB or RB. The most likely explanation is that the SSR, under these circumstances, results from a central command. The recovery to normal SBF is faster after the VM as compared to SDI. This suggests that the withdrawal of sympathetic responses is faster after the VM. The explanation for this is unknown but suggests that it might be baroreceptor mediated.

[From tobacco use to other drugs use: does the early use of tobacco increase the probability of use of other drugs]. / Del tabaco al uso de otras drogas: el uso temprano de tabaco aumenta la probabilidad de usar otras drogas?

OBJECTIVE: To assess the likelihood of substance abuse predicted by age of first exposure to tobacco. MATERIAL AND METHODS: Data from the 1998 National Household Survey on Addictions in urban areas were analyzed. RESULTS: The age period of greater likelihood of drug experimentation is between 15 and 19 years; only 5.6% of drug users and 13% of alcohol beverage drinkers reported having experimented with drugs before trying tobacco. The probability of heavy drinking and dependence was higher at early ages of first exposure to tobacco and decreased with increasing age. Experimentation with drugs, continued use, and multiple drug use, are more frequent among smokers who started before 15 years of age. CONCLUSIONS: Early tobacco use increases the likelihood of substance abuse.

Respuesta del flujo sanguíneo de la piel con diferentes maniobras respiratorias en sujetos sanos / Response of skin blood flow to several respiratory maneuvers in healthy subjects

INTRODUCTION: In the diagnosis of autonomic disturbances, the variability of skin blood flow (SBF) and the sympathetic skin response (SSR) in response to several respiratory maneuvers are not routinely studied. OBJECTIVE: We sought to standardize the method of SBF variability and SSR in healthy subjects during four respiratory maneuvers: 1) spontaneous breathing (SB); 2) rhythmic breathing at a rate of 6 per minute (RB); 3) sudden deep inspiration (SDI); 4) Valsalva maneuver (VM). SUBJECTS, MATERIAL AND METHOD: We studied 30 healthy subjects with a mean age of 32 years, 60 were men and 40 women. We used a photopletysmograph in the finger pad to measure SBF and surface electrodes on the palms of the hand to register the SSR. We also recorded the ECG and the respiratory movements. The variables were: 1) amplitude of SBF; 2) latency and duration of SSR; 3) percentage of decrease of the SBF during the maneuvers compared with the basal flow. RESULTS: During spontaneous breathing there was no respiratory modulation of the SBF and during RB the SBF was modulated with respiration. With SDI there was a 60 decrease of the SBF. VM induced a larger SBF decrease of 72 per cent. A significant statistical difference was revealed when we compared the decrease of SBF basal breathing with SDI and VM (P < 0.001). The difference was also significant between the SDI and VM (P < 0.001). The SBF decrease recovered more slowly after the SDI (beat 7) than after the VM (veat 6). The SBF decrease was more pronounced in magnitude during the VM. The latency of the SSR appears spontaneously and at random in 57 of subjects during normal breathing but it appeared consistently during RB, SDI, and VM. The latency of SSR was longer during SB (1.7 +/- 0.7 s), RB (1.6 +/- 0.7 s) than SDI (0.7 +/- 0.5 s) and VM (0.8 +/- 0.9 s) (P > 0.050). Duration of the SSR was significantly longer in the SDI (around 7.8 +/- 2.4 s) and during the VM (8 +/- 2.5 s) as compared to normal breathing (6.3 +/- 1.0 s) and RB (6.4 +/- 1.5 s) (P < 0.009). CONCLUSIONS: SB and RB induce periodic modulation of sympathetic activity to skin blood vessels and sweat glands. SDI and VM produced a much greater activation of sympathetic skin activity than SB and RB. The increased SSR duration and the profound SBF decrease with SDI and VM as compared to SB or RB are consistent with this hypothesis. The latency of the SSR is much shorter with SDI and VM than with SB or RB. The most likely explanation is that the SSR, und

Del tabaco al uso de otras drogas: ¿el uso temprano de tabaco aumenta la probabilidad de usar otras drogas? / x

Objetivo. Analizar la probabilidad de abuso de sustancias en relación con la edad de inicio del consumo de tabaco. Material y métodos. Los datos provienen de la Encuesta Nacional de Adicciones (1998) realizada en población urbana. Resultados. La edad de mayor riesgo para experimentar con sustancias es entre los 15 y los 19 años. Solamente en 5.6 por ciento de los usuarios de drogas y 13 por ciento de los que han consumido alcohol, el uso del tabaco no ocurrió primero. La probabilidad de beber en forma consuetudinaria y de presentar dependencia es mayor cuando la edad de inicio es temprana y disminuye en la medida en que se retrasa la edad de inicio. La experimentación con drogas, el continuar usándolas y el poliuso son más frecuentes entre quienes se iniciaron antes de los 15 años. Conclusiones. El inicio temprano en el consumo de tabaco incrementa la probabilidad de uso y abuso de sustancias.

Objective. To assess the likelihood of substance abuse predicted by age of first exposure to tobacco. Material and Methods. Data from the 1998 National Household Survey on Addictions in urban areas were analyzed. Results. The age period of greater likelihood of drug experimentation is between 15 and 19 years; only 5.6 percent of drug users and 13 percent of alcohol beverage drinkers reported having experimented with drugs before trying tobacco. The probability of heavy drinking and dependence was higher at early ages of first exposure to tobacco and decreased with increasing age. Experimentation with drugs, continued use, and multiple drug use, are more frequent among smokers who started before 15 years of age. Conclusions. Early tobacco use increases the likelihood of substance abuse.