Tempo and mode in coevolution of Agave sensu lato (Agavoideae, Asparagaceae) and its bat pollinators, Glossophaginae (Phyllostomidae).

The genus Agave sensu lato contains ca. 211 described species, many of which are considered keystone species because of their ecological dominance and the quantity of resources they provide with their massive, nectar-rich inflorescences. The large diversity of Agave species has been hypothesized as being related to their reproductive strategy (predominantly monocarpic) and diverse pollinators (e.g., bats, hummingbirds, hawkmoths). In particular, Agave species provide resources that a few genera of nectar feeding bats from the subfamily Glosophaginae are dependent upon. To explore a possible coevolutionary relationship between Agave and the bat species that pollinate them, we calibrated molecular phylogenies of both groups and looked for a correlation in their dates of divergence. One coding and two non-coding regions of the chloroplast genome were sequenced from 49 species of the Agavoideae (Asparagaceae), and the mitochondrial gene Cyt-b and nuclear coding gene RAG2 were either sequenced or obtained from gene bank for 120 Phyllostomid bats. Results from the analyses indicate that Agave sensu lato is a young genus (estimated crown age 2.7-8.5/stem age 4.6-12.3 Ma), with an increasing diversification rate, and the highest speciation rate among Agavoideae's clades. The origin of the Glossophaginae bats (stem age 20.3-23.5 Ma) occurred prior to the stem age of Agave sensu lato, while the origin of the current pollinators of Agave species, members of the genera Glossophaga, Leptonycteris, Anoura, Choeronyscus, Musonycteris and Choeronycteris, was estimated to be around 6.3-16.2 Ma, overlapping with the stem age of Agave sensu lato, supporting the hypothesis of diffuse coevolution.

iSGLT2 y su potencial efecto nefroprotector en pacientes con diabetes mellitus 2 / iSGLT2 and its potential nephroprotector effect in patients with diabetes mellitus 2

Resumen: La diabetes mellitus 2 es una epidemia mundial, aunado a esto, la nefropatía diabética se ha convertido en la principal causa de insuficiencia renal en etapa terminal. En los pacientes con diabetes mellitus 2 existe sobreexpresión de los cotransportadores de glucosa ligados a la vía del sodio tipo 2 (SGLT2) que contribuyen al mantenimiento de la hiperglucemia. Por tanto, los inhibidores de este transportador representan un tratamiento innovador independiente de la acción de la insulina o la función de las células beta pancreáticas. En estudios recientes se ha demostrado que los iSGLT2 tienen efectos benéficos en la microvasculatura, en especial en la progresión de la nefropatía diabética. Este efecto no sólo se debe a la mejora del control glucémico, sino también a efectos directos en el riñón. Los iSGLT2, al inducir la glucosuria, revierten la glucotoxicidad renal. En estudios experimentales se ha observado que, además, se reduce la hiperfiltración, así como los marcadores inflamatorios y fibróticos. También se ha visto reducción del volumen circulante efectivo y aumento en la actividad de bloqueadores del sistema renina-angiotensina-aldosterona (bloqueadores RAA) circulantes, creando así un efecto nefroprotector.

Abstract: Type 2 diabetes mellitus 2 (DM2) is already a worldwide epidemic, in addition, diabetic nephropathy has become the leading cause of end-stage renal failure. In patients with DM2 there is an increased expression of the sodium-glucose cotransporters 2 (SGLT2) that contribute to the maintenance of hyperglycemia. Therefore, the inhibitors of this transporter represent an innovative therapy independent of the action of insulin or the function of pancreatic beta cells. Recent studies have shown that iSGLT2 have beneficial effects on microvasculature, especially in the progression of diabetic nephropathy. This effect is due not only to improved glycemic control but also to direct effects on the kidney. iSGLT2 induce glycosuria to reverse renal glucotoxicity. In experimental studies it has been observed that, in addition, hyper-filtration as well as inflammatory and fibrotic markers are reduced. There has also been a reduction in effective circulating volume and an increase in the activity of circulating renin-angiotensin-aldosterone system blockers (RAA blockers), thus creating a nephroprotective effect.

The relationship between asthma symptoms and anthropometric markers of overweight in a Hispanic population.

BACKGROUND: Previous studies have revealed the relationship between asthma and obesity, but the relationship with other markers of overweight and obesity has not yet been investigated. OBJECTIVE: To establish the relationship between asthma symptoms and simple anthropometric indexes (BMI, waist circumference (WC), and waist-to-hip ratio (WHR)) as markers of overweight in an adult Hispanic population. METHODS: The data were obtained from the PRIT (Prevalence of Cardiovascular Risks in General Hospital Workers) 2001 survey. The participants were workers at the Hospital General de México in Mexico City and included 135 men and 398 women aged 43.8 +/- 11.9 and 43.0 +/- 10.5, respectively. Odds ratios for asthma symptoms at different BMI, WC, and WHR cutoff points associated with excessive weight were calculated. The likelihood ratios for having asthma symptoms in participants with various cutoff values of BMI, WC, and WHR also were calculated. RESULTS: Asthma symptoms were not related to anthropometric markers of overweight or obesity in men, while they were associated in women with WC cutoff levels of 80 and 85 cm, and BMI of 25 and 27 kg/m2. No level of WHR was related to asthma symptoms in women. In women, the likelihood ratio for asthma symptoms increased proportionally from WC levels of 73.5 cm up to 86 cm, while this risk increased significantly from BMI levels of 22 up to 29 kg/m2. CONCLUSION: Overweight as assessed by BMI and WC (but not WHR) was related to asthma symptoms in women in the studied population.

Evolution of the prevalence of obesity in the workers of a general hospital in Mexico.

OBJECTIVE: The objective of this study was to compare the prevalence of overweight and obesity in the first Prevalencia de factores de nesso cardiovascular en Trabajadores survey (1994) with the prevalence of overweight and obesity observed in the second survey (1996). RESEARCH METHODS AND PROCEDURES: For both surveys the following individual data were collected: age, sex, weight, height, and body mass index (BMI). The 1994 survey included 2383 people and the 1996 survey included 2759 people. The degree of BMI was classified according to the current World Health Organization definitions. The population was divided by gender and age group, and the prevalence of each level of overweight was calculated. Additionally, the prevalence of different cutoff levels of BMI was calculated by gender and age groups. RESULTS: The global prevalence of age-adjusted overweight increased from 26.91% to 37.45%. This increase was observed in both genders but the men had a higher increase from 24.51% to 40.21%. Overweight was more frequent in men than in women in all age groups. Male overweight prevalence was higher in the 40- to 59-year-old group and > or = 60-year-old group. Female overweight prevalence was predominant in the 30- to 39-year-old, 40- to 49-year-old, and 50- to 59-year-old groups. Global prevalence of obesity (> or =30 kg/m(2)) changed from 13.8% to 17.2%. Particularly, global prevalence of obesity class I increased from 9.66% to 12.6%; in men this figure increased from 9.04% to 13.05% and in women from 9.9% to 12.71%. DISCUSSION: Prevalence of overweight and obesity has increased significantly in the studied population. It is necessary to implement lifestyle modifications to prevent the increase of prevalence of overweight and obesity.

Second phase of a double-blind study clinical trial on Sibutramine for the treatment of patients suffering essential obesity: 6 months after treatment cross-over.

OBJECTIVE: To evaluate the weight gain after Sibutramine 10 mg daily discontinuation. To evaluate the effect of Sibutramine 10 mg daily in patients who were on a diet for 6 months. DESIGN: After a double-blind, placebo-controlled, parallel, prospective phase for 6 months, the treatments were crossed over and the patients continued in double-blind observation for another 6-month period. SUBJECTS: Forty out of 44 patients who were on Sibutramine and 42/44 who were on placebo switched the trial medication. All the patients were obese at the beginning of the trial (body mass index, BMI>30 kg/m(2)). During the first phase, the weight loss in the Sibutramine group was 7.52 kg (95% confidence intervals (95% CI) 6.15; 8.9) and that in the placebo group 3.56 kg (95% CI 2.41; 4.7) (using last observation carried forward (LOCF)). MEASUREMENTS: Body weight, BMI, waist, medical history, assessment of hunger, satiety and diet compliance, standard laboratory assessments, blood pressure, heart rate and ECG. RESULTS: Thirty out 40 patients in the Sibutramine/placebo (S/P) group and 32 out of 42 in the placebo/Sibutramine (P/S) group completed the second phase of the trial. During the second part of the trial the S/P gained 3.21 (95% CI 2.15; 4.26) kg, 1.21 (0.82; 1.59) kg/m(2), and 2.83 (1.55; 4.12) waist cm. The P/S group lost 1.62 (2.62; 0.61), 0.67 (1.09; -0.25) kg/m(2), and 1.85 (3.18; 0.53) waist cm. Eleven patients in the S/P group suffered 14 adverse events, mainly blood pressure increase (n=4); 19 patients in the P/S group had 29 adverse events, mainly dry mouth (n=8), constipation (n=5) and blood pressure increase (n=4). Only one P/S patient withdrew because of an adverse event. CONCLUSIONS: After Sibutramine discontinuation patients had weight gain but they did not reach the baseline body weight. No significant adverse events presented after Sibutramine discontinuation. When Sibutramine was administrated to patients after 6 months of diet, the weight plateau was broken. Early Sibutramine administration had better effects than late post-diet administration. Sibutramine was well tolerated by the patients.

Anthropometric indexes in the prediction of type 2 diabetes mellitus, hypertension and dyslipidaemia in a Mexican population.

OBJECTIVE: To determine values of simple anthropometric measurements which are associated with the presence of type 2 diabetes mellitus, hypertension and dyslipidaemia and to assess anthropometric cut-off values for predicting the likelihood of these chronic conditions in a Mexican population. DESIGN AND SETTING: The data were obtained from PRIT (Prevalence of Cardiovascular Risk Factors in General Hospital Workers) surveys from 1994 to 2000 adjusted to the structure of the overall Mexican population. SUBJECTS: A total of 2426 men and 5939 women aged 38.99+/-7.11 and 39.11+/-14.25 y, respectively. MEASUREMENTS: The optimal sensitivity and specificity of using various cut-off values of BMI (body mass index), WHR (waist-to-hip ratio), WC (waist circumference) and WTH (waist-to-height ratio) to predict type 2 diabetes mellitus (DM), hypertension (HT), or dyslipidaemia were examined by receiver operating characteristic curve (ROC) analysis. The likelihood ratios for having diabetes, hypertension and dyslipidaemia in subjects with various cut-off values of BMI, WHR, WC and WTH were calculated. Multiple step-wise logistic regression analysis was used to examine the independent relationship between the anthropometric indexes, age and smoking, and the odds ratio of having chronic conditions. RESULTS: The BMI cut-off to predict DM, HT, or dyslipidaemia varied from 25.2 to 26.6 kg/m2 in both men and women. The optimal WC cut-offs were 90 cm in men and 85 cm in women. The WHR cut-off was about 0.90 in men and 0.85 in women, and the optimal WTH cut-off was 52.5 in men and varied from 53 to 53.5 in women. The cut-off levels for WC, WHR and WTH corresponded to the inflexion points in the likelihood ratio graphs. In the case of BMI likelihood ratio graphs, we found a significant increase in the risk for chronic conditions from 22 to 23 BMI levels in both genders. Logistic regression analyses disclosed that only BMI and age were included in all the models as well as the influence of smoking in DM and dyslipidaemia in men. CONCLUSION: Although these results may not be readily applied to the rest of the Mexican population or to other Hispanic populations, they point to the necessity of similar studies with large randomized samples to find the cut-off levels for chronic conditions in different populations.

A clinical trial of the use of sibutramine for the treatment of patients suffering essential obesity.

OBJECTIVE: To evaluate the safety and efficacy of Sibutramine 10 mg per os, once a day in obese patients over a period of 6 months. DESIGN: A monocenter, double-blind, placebo-controlled, parallel, prospective clinical trial. SUBJECTS: 109 male and female obese patients (BMI>30 kg/m2) from 16 to 65 y entered the trial. MEASUREMENTS: Body weight, body mass index (BMI), waist and waist/hip ratio, medical history, assessment of hunger, satiety and diet compliance, standard laboratory assessments, blood pressure, heart rate and ECG. RESULTS: 40 out of 55 patients in the Sibutramine group and 44 out of 54 patients in the placebo group completed the trial. Using the method of last observation carried forward (LOCF), the weight loss in the Sibutramine group was 7.52 kg (95% confidence intervals (95% CI) 6.15; 8.9) and that in the placebo group was 3.56 kg (95% CI 2.41; 4.7). The BMI loss was 3.14 kg/m2 (95% CI 2.58; 3.69) in the Sibutramine group and 1.46 kg/m2 (95% CI 0.99; 1.93) in the placebo group. The waist reduction was 12. 51 cm (95% CI 9.25; 15.77) in the Sibutramine group and 3.26 cm (95% CI 1.38; 5.14) in the placebo group (P<0.05 by paired Student's t-test for all the intragroup comparisons). 32 Sibutramine patients had 45 adverse events, the most frequent adverse events in the Sibutramine group being dry mouth (n=19), increase in blood pressure (n=5), constipation (n=5) and tachycardia (n=5); 23 placebo patients had 29 adverse events, mainly increase in blood pressure (n=11) and dry mouth (n=10). Two Sibutramine patients withdrew from the trial due to adverse events. CONCLUSION: Sibutramine induces significant loss of body weight, BMI and waist, but does not significantly affect cardiovascular function. Sibutramine was well tolerated by most of the patients.

Effects of metformin on fibrinogen levels in obese patients with type 2 diabetes.

OBJECTIVE: To determine fibrinogen levels in obese patients with type 2 diabetes and assess its changes with the use of metformin. METHODS: 60 obese patients (BMI > 27) with type 2 diabetes were studied in an open, two phase, prospective, randomized and comparative study. The pre-treatment phase was a period of four weeks of a controlled diet. In the treatment phase they were divided in two subgroups of 30. One received metformin as a daily single tablet of 850 mg and increasing the dosage to two or three tablets depending on their metabolic control. The second subgroup received 24 units of DNA-recombinant insulin subcutaneously (two thirds of dose before breakfast, and the remaining third before dinner). The insulin dosage was adjusted according to the metabolic response. A control group was formed by 60 non diabetic obese patients with only the controlled diet. RESULTS: The mean values of plasma glucose, fibrinogen levels and body mass index did not change in the pretreatment phase in controls and diabetics. These parameters decreased significantly in the metformin subgroup in the treatment phase (p < 0.001). Only glucose decreased in the insulin subgroup. There were no changes in the controls. CONCLUSIONS: In addition to improving metabolic control, metformin showed to be a good therapeutic alternative in modifying fibrinogen levels in type 2 diabetic patients.

Comparative accuracy of glucose monitors.

BACKGROUND: Self-monitoring of blood glucose levels has become an important instrument for the management of patients with diabetes mellitus. Both patients and physicians expect that the monitors will provide reliable results. Numerous environmental, physiologic, and operational factors can affect system performance, yielding results that are inaccurate or unpredictable. METHODS: This study examined the effect of one factor--high altitude--on the performance of seven blood glucose monitoring systems. The following monitors were compared: two One Touch II; two One Touch Basic; two Reflolux II (Accu-Chec in the USA); two Glucometer 3; one Glucometer 2, and one Accutrend Alpha. Double blood glucose level values were compared with a controlled reference laboratory test value, which was unknown to the investigator until the end of the study because the study was double blind. Blood glucose values were obtained using each of the monitors in 200 patients; 150 with diabetes mellitus, and 50 healthy subjects. RESULTS: The One Touch monitors were the only monitors that reported adjusted straight lines (Y = a+bX) that were very similar for all three techniques. In addition, these adjusted straight lines are those closest to the ideal line, Y = X. These same monitors were the only ones that did not reject the null hypothesis Ho: a = 0. The relative deviation index at the 20% level was less than 3.5% for the One Touch II and One Touch Basic monitors; for the rest of the monitors, the index was over 14%. The clinically accepted EGA region was similar for all study monitors. CONCLUSIONS: In conclusion, the One Touch II and One Touch Basic Monitors showed greater accuracy in comparison to the other devices. The evaluation of the clinically acceptable region shows practical reliability for all of the monitors used.

Prevalence of coronary artery disease risk factors in workers at the general hospital of Mexico of the ministry of health.

OBJECTIVE: To assess the prevalence of coronary risk factors in 2,463 health-care workers at the General Hospital of Mexico. METHODS: The study participants--1,620 women (65.8%) and 843 men (34.2%)--ranged in age from 16 to 65 years old. Study subjects were classified into five occupational subgroups: maintenance workers, 477 (19.4%); administrators, 697 (28.3%); physicians, 495 (20.1%); nursing staff, 559 (22.7%); and students, 235 (9.5%). For each participant, a clinical history was elicited, anthropometric determinations were done, and samples were obtained for determining blood glucose, total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglyceride levels. RESULTS: Cholesterol levels above 6.2 mmol/L (>240 mg/dL) were found in 14.9% of the women and 14.8% of the men in the overall study group. Triglyceride levels of more than 2.25 mmol/L (>200 mg/dL) were found in 471 participants (19.1%). The prevalence of obesity was 13.5%, and high blood pressure was detected in 22.2% of study participants. Only 32.2% of subjects engaged in physical exercise one or more times per week; moreover, 32% of those surveyed smoked. The prevalence for diabetes mellitus was 6.25%. The multifactorial coronary risk index was high in 13.2% of men and 43.2% of women older than 30 years of age. CONCLUSION: This study confirmed the high prevalence of risk factors for cardiovascular diseases in personnel of the General Hospital of Mexico. Because many of these risk factors are modifiable, educational efforts and preventive measures should be implemented.

[The prevalence of risk factors for coronary disease in workers of the Hospital General de México]. / Prevalencia de factores de riesgo de enfermedad coronaria en trabajadores del Hospital General de México.

OBJECTIVE: To evaluate the prevalence of risk factors of coronary heart disease in the personnel of the General Hospital in Mexico City. MATERIAL AND METHODS: We studied 2,228 workers, 1,531 female (68.7%) and 697 male (31.2%) whose ages ranged from 16 to 65 years old in the period of 1993 to 1995. They were divided in work areas: Intendancy 477 (21.4%), Administrative, 697 (31.2%), Physicians, 495 (22.2%) and Nurses, 559 (25.0%). We collected clinical histories, anthropometric measures, and laboratory determinations of glucose, total cholesterol, LDL, HDL and triglicerydes. RESULTS: We found that 367 (14.9%) had total cholesterol above 240 mg/dl, with high values in females of the administrative area (17.1%) and males in the nursing department (26%), which was the highest tendency. Trigliceryde levels above 200 mg/dl were found in 208 males (24.6%) and 263 females (16.2%), with high prevalence in the nursing and administrative departments, in males (39.1 and 34.1% respectively). Obesity was present in 236 females (14.5%) and 97 males (11.5%). High blood pressure in 549 individuals (22.2%), 297 females (18.3%) and 252 males (29.8%) without significance regarding to work area. Smoking habits were positive in 32% of the total with highest prevalence in males from 30 to 45 years and in females from 30 to 50 years. We found an incidence of 6.24% of diabetes in all the subjects studied, 2.27% ignored the diagnosis at the moment they were studied. CONCLUSIONS: In this study we confirmed the high prevalence of risk factors of coronary heart disease in personnel of the General Hospital in Mexico City. In most cases, these risk factors that can be modified and, therefore, prevented.

Metformin's effects on glucose and lipid metabolism in patients with secondary failure to sulfonylureas.

OBJECTIVE: To compare results obtained with metformin versus those obtained with DNA-recombinant insulin in obese patients with NIDDM suffering from secondary failure to sulfonylureas. RESEARCH DESIGN AND METHODS: We conducted an open, prospective, randomized, and comparative study comprising a total of 60 patients selected and placed in two parallel groups. We had previously confirmed that the subjects had secondary failure to high doses of sulfonylureas. The initial metformin dosage was a single 850 mg tablet, and the dosage was increased to two or three tablets depending on the patient's metabolic changes. The initial dosage of DNA-recombinant insulin was 24 U, subcutaneously administered and divided into two portions: two-thirds at around 8:00 A.M., before breakfast, and the remaining third at 8:00 P.M., before dinner. The dosage was adjusted based on the patient's clinical and metabolic response. RESULTS: The initial average glucose value for the metformin group was 269.1 +/- 32.2 mg/dl, decreasing by the end of the study to 159.7 +/- 30.5 mg/dl. For the insulin group, these figures went from 270.7 +/- 24.0 mg/dl at the beginning of the study to 134.8 +/- 26.7 mg/dl. This decrease correlates with the reduction in glycosylated hemoglobin from 12.8 to 8.9% for the first group and from 12.3 to 8.2% for the second, as well as with the reduction in triglyceride values from 230.3 to 183.1 mg/dl and from 218.4 to 186.3 mg/dl, respectively. The BMI (27.5-26.4), blood pressure (systolic from 145.7-132.1 mmHg, diastolic from 90.3-84.8 mmHg), and total cholesterol levels (235-202 mg/dl) decreased in only the metformin group. CONCLUSIONS: Metformin is an effective, safe, and well-tolerated treatment that improves metabolic control and favorably modifies secondary clinical alterations due to insulin resistance, such as arterial hypertension, overweight, and hyperlipidemia, in obese patients with NIDDM suffering from secondary failure to sulfonylureas.

[The efficacy, safety and tolerance of fluvastatin sodium 40 mg in patients with hyperlipidemia type IIA]. / Eficacia, seguridad y tolerabilidad de la fluvastatina sódica 40 mg en pacientes con hiperlipidemia tipo IIA.

Fluvastatin sodium is the first wholly synthetic 3 hydroxy-3-methylglytary 1 coenzyme A reductase inhibitor. It reduces cholesterol synthesis, enhances low density lipoprotein catalysis and hepatocyte LDL receptor expression. To evaluate the efficacy, tolerability and safety of fluvastatin sodium 40 mg once a day, we studied 40 patients with type IIA dyslipidemia. We observed a statistically significant reduction in total cholesterol (20.7%, p < 0.01), low density lipoprotein cholesterol (29.5%, p < 0.01), triglycerides (10.56%, p N.S.), very low density lipoprotein cholesterol (10.56%, p N.S.), C-LDL:C-HDL (33.7%, p < 0.01) and an increase in high density lipoprotein cholesterol (2.8%) after 12 weeks of treatment. No patient reported side effects and no clinically significant modifications in safety parameters were observed during the study. We conclude that fluvastatin sodium 40 mg once daily is efficacious, safe and well tolerated in the treatment of type IIA primary dyslipidemia.

Quiste epidermoide hipotalámico e hiperprolactinemia secundaria / Hypotalamic epidermoid cyst and secundary hyprprolactinemia

La hiperprolactinemia secudaria a tumor hipotalámo es una patología poco frecuente de gran interés clínico. Se presenta el caso de una mujer de 32 añosde edad con padecimiento de siete meses de evolución manifestado por cefalea intermitente, disminución de la agudeza visual, amenorrea y galactorrea. Posteriormente inicia poliuria, polidipsia, hiperfagia, aumento ponderal y trastornos del sueño. a la exploración física se encontró defecto campimétrico visual, alteración de los pares craneales I, II, III y VII y lesión piramidal. Los estudios hormonales fueron compatibles con diabetes insípida y síndrome hiperprolactinémico. La tomografía computada evidenció la presencia de tumoración hipotalámica hiperémica con componenete quístico. La paciente fue intervenida quirúrgicamente, encontrándose tumor quístico de la línea media de la región hipotalámica, el cual no pudo ser extirpado en su totalidad, reportándose como diagnóstico anatomopatológico definitivo quiste epidermoide de la línea media. La evolución postquirúrgica de la paciente fue mala, fallecido 48 horas después de la cirugía.