Tumor necrosis factor haplotype diversity in Mestizo and native populations of Mexico.

The so-called tumor necrosis factor (TNF) block includes the TNFA, lymphotoxin alpha and beta (LTA and LTB) genes with single-nucleotide polymorphisms (SNP) and microsatellites with an allele frequency that exhibits interpopulation variability. To date, no reports have included both SNPs and microsatellites at the TNF block to study Mestizo or Amerindian populations from Mexico. In this study, samples of five Mexican Mestizo populations (Durango, Guadalajara, Monterrey, Puebla, and Tierra Blanca) and four native-Mexican populations (North Lacandonians, South Lacandonians, Tepehuanos, and Yaquis) were genotyped for two SNPs (LTA+252A>G and TNFA-308G>A) and four microsatellites (TNFa, d, e, and f), to analyze the genetic substructure of the Mexican population. Allele and haplotype frequencies, linkage disequilibrium (LD), and interpopulation genetic relationships were calculated. There was significant LD along almost all of the TNF block but the lowest D' values were observed for the TNFf-TNFd pair. Mestizos showed higher allele and haplotype diversity than did natives. The genetic differentiation level was reduced among Mestizos; however, a slightly, but significant genetic substructure was observed between northern and southern Mexican Mestizos. Among the Amerindian populations, the genetic differentiation level was significantly elevated, particularly in both North and South Lacandonians. Furthermore, among Southern Lacandonians, inhabitants of Lacanja town were the most differentiated from all the Mexicans analyzed. The data presented here will serve as a reference for further population and epidemiological studies including these TNF polymorphisms in the Mexican population.

Restoration of endocrine function and fertility with a tubo-ovarian autotransplant as the anatomical-functional unit in rabbits using a vascular microsurgical technique.

Infertility has been considered a global public health problem in many countries worldwide. Our objective was to restore endocrine function and fertility in tubal-oophorectomized rabbits using an orthotopic tubal-ovarian vascularized autotransplant model as the anatomical-functional unit while employing a microvascular surgical technique. Twenty New Zealand white (NZW) sexually mature female rabbits and four male NZW rabbits of proven fertility were divided into two study groups. In group I (n = 10), a left salpingo-oophorectomy was performed. Group II (n = 10) was subjected to a bilateral salpingo-oophorectomy, plus a right orthotopic tubal-ovarian autotransplant. Our testing variables were vascular and tubal-anastomoses permeability, estradiol (E2) and progesterone (P4) serum levels, pregnancy, number of offspring, histopathological study of the uteri, fallopian tubes, and ovaries. One hundred percent immediate permeability of the tubal anastomoses was achieved, while late permeability was found to be 64%. Immediate permeability of vascular anastomoses was 90%, and late permeability was recorded at 80%. E2 serum levels in both groups at different times showed no statistically significant differences. In the case of P4, a small difference was found during pregnancy, especially greater in the control group (P < .05). In the autotransplanted group, four rabbits became pregnant (44%). Endocrine function and fertility were restored in the rabbits with the tubal-ovarian transplant as the anatomical-functional unit. The use of isotransplants and allotransplants should be considered a therapeutic alternative in the infertile woman with irreparable bilateral tubal damage, ovarian dysgenesis, surgical absence of ovaries and fallopian tubes, or when the conventional IVF/TE in these cases has been unsuccessful.

DNA polymorphism analysis of candidate genes for type 2 diabetes mellitus in a Mexican ethnic group.

Type 2 diabetes mellitus is a complex metabolic disorder resulting from the action and interaction of many genetic and environmental factors. It has been reported that polymorphisms in genes involved in the metabolism of glucose are associated with the susceptibility to develop type 2 diabetes mellitus. Although the risk of developing type 2 diabetes mellitus increases with age, as well as with obesity and hypertension, its prevalence and incidence are different among geographical regions and ethnic groups. In Mexico, a higher prevalence and incidence has been described in the south of the country, and differences between urban and rural communities have been observed. We studied 73 individuals from Santiago Jamiltepec, a small indigenous community from Oaxaca State, Mexico. This population has shown a high prevalence of type 2 diabetes mellitus, and the aim of this study was to analyze the relationship between the Pst I (insulin gene), Nsi I (insulin receptor gene) and Gly972Arg (insulin receptor substrate 1 gene) polymorphisms and type 2 diabetes mellitus, obesity and hypertension in this population. Clinical evaluation consisted of BMI and blood pressure measurements, and biochemical assays consisted of determination of fasting plasma insulin and glucose levels. PCR and restriction enzyme digestion analysis were applied to genomic DNA to identify the three polymorphisms. From statistical analysis carried out here, individually, the Pst I, Nsi I and Gly972Arg polymorphisms were not associated with the type 2 diabetes, obese or hypertensive phenotypes in this population. Nevertheless, there was an association between the Nsi I and Pst I polymorphisms and increased serum insulin levels.

Correlation between serum leptin levels and insulin sensitivity in diffuse toxic goiter.

OBJECTIVE: The aim of this survey was to assess the correlation between leptin and insulin sensitivity (IS) in cases of diffuse toxic goiter. DESIGN, PATIENTS, MEASUREMENTS: This is a descriptive study on patients with diffuse toxic goiter (DTG) assessing their body mass index (BMI), serum leptin concentrations, circulating insulin (area under the curve (AuC) of insulin), average insulin level, thyroid hormones, thyroid stimulating hormone (TSH), glycemia and IS (using a hyperinsulinemic-euglycemic clamp and the homeostasis model for assessment of insulin resistance (HOMA-IR) before and after euthyroidism induced with metimazol. RESULTS: The average patient age was 35 years old (range 31-40 years), height was 157 cm (range 151-160 cm), glycemia was 4.3 +/- 0.3 mmol/L and TSH 0.1 +/- 0.1 microU/mL. Average leptin level was 11.3 +/- 2.8 ng/dL, the average insulin level was 10.13 +/- 3.7 mIU/mL and the AuC for insulin was 50.6 +/- 18 microIU x min/mL. No correlation was found between leptin and BMI, thyroid hormones and glycemia. While controlling for the BMI effect, a correlation was found between leptin and TSH (r = -0.77, p = 0.042), as well as between leptin and insulinemia (r = 0.93, r2 = 0.86, p = 0.001) independently from the state of thyroid function. There was a tendency for a high correlation between leptin and the insulin AuC (hyperthyroidism: r = 0.89, p = 0.056; euthyroidism: r = 0.99, p = 0.056). A negative correlation was found between IS and the insulin AuC (rho = -0.58, p = 0.18). There was a high tendency for correlation between leptin and IS when the BMI effect (HOMA-IR: r = 0.70, p = 0.12; PHE: r = -0.55, p = 0.26) was taken into consideration. CONCLUSIONS: There is a high tendency for a negative correlation between leptin and IS when the BMI effect is controlled. There is a high tendency for a positive correlation between leptin and insulin and TSH.

[Effect of induced diabetes on reproduction and development]. / Efecto de la diabetes inducida sobre la reproducción y el desarrollo.

Diabetes mellitus is a major cause of morbidity and mortality and it has been studied in relation to the organs that affects, and the reproduction system is not the exception. Scientists had developed experimental animal models to investigate the effects of diabetes using different substances being streptozotocin (STZ) the most effective. STZ is natural compound produced by the Streptomyces achromogenes that selectively destroys the beta cells of the pancreas breaking the DNA. It has been proved that equilibrated solutions of STZ stored at 6 degrees C, are very effective in inducing diabetes to several animal species such as rat, mouse and hamster. In rats, the disorders in reproduction have been associated to dysfunctions in the hipotalamohipofisis-gonadal axis, given by a reduction in the secretion of GnRH, as well as of LH, FSH, prolactin and alterations in the gonadal secretion of steroids (testosterone, estrogens, progesterone). Due to this situation, male production of spermatozoids as well as its' motility is impair. In females, the principal effects are ovaric atrophy, impaired folliculogenesis, insufficiency of the corpora lutea, and problems associated with the maintenance of pregnancy. Many researchers had associated the prevalens of congenital malformation with a hiperglucemic state, being the most common retardation of the development, defects in the closure of the neural tube, micrognatias, heart malformations, etc.

A diabetic retinopathy screening program as a strategy for blindness prevention.

The most frequent cause of preventable blindness in adults, in the developed world, is diabetic retinopathy (DR). The early treatable phase of this complication is clinically silent. In order to institute effective laser photocoagulation and prevention of blindness, timely detection is crucial. Consequently there is a need for periodic funduscopic examinations of all diabetics. Due to the high prevalence of DM in Mexico most of the primary care facilities are limited. We present the results of a DR screening program (DRSP) using a mobile unit equipped with a fundus photography camera, parked outside of a clinic. We report the prevalence of the various stages of DR and clinical characteristics observed in this population as well as our experience working in such an environment. The study period was from September 1 to December 22, 1995. All the diabetics that presented for care to the clinic were identified and all other persons were invited to participate. A total of 231 participants were invited (112 men, 119 women). Non-stereo fundus photos of two retinal fields (macula and optic disk centered) were taken with technique and classification according to international standards. Response rate to the invitation was 95.3%. Mean age was 62.4 +/- 13 years and 63.5 +/- 10 years and duration of diabetes was 12.3 +/- 10.1 years and 11.0 +/- 7.5 years for men and women, respectively. DR was detected in 38% of the cases, of these only 5.6% have received treatment. DR was uncovered in 84.5% of the cases and was associated with duration of diabetes (p < 0.001 in men and p = 0.04 in women) and hyperglycemia (in men p < 0.005, only). DR has a high prevalence in this population and can be detected through a screening program which reveals undiagnosed high risk DR in an efficient, and standardized manner.

[Torsade de pointes in myxedema. Report of a case and review of the literature]. / Torsade de pointes en mixedema. Informe de un caso y revisión de la literatura.

A 57 years old female suffered from recurrent attacks of ventricular tachycardia including one episode of torsade de pointes, she had hypothyroidism with myxedema secondary to Sheehan Syndrome, following thyroid replacement therapy the tachyarrhythmia did not relapse and there was no need to give specific antiarrhythmic therapy.

Nephropathy in low income diabetics: the Mexico City Diabetes Study.

Among the most serious complications associated with diabetes mellitus (DM) is nephropathy (DN). In Mexico, there is little information on the frequency and clinical characteristics of DN in the Mexican population. We present results of a population-based survey designed to estimate the prevalence of DN. The low income population consisted of 15,532 inhabitants. All 35- to 64-year-old males and non-pregnant women residing in the survey area were identified as eligible for the study (3505; 22.6%). A home interview was obtained in 2810 (80.2%). A physical exam with oral glucose tolerance test was obtained in 2282 (81.2% of those interviewed). DM was diagnosed in 304 (crude rate 13.3%). Mean age for men and women with DM was 51.6 +/- 8.4 and 52.2 +/- 7.5, respectively. Duration of DM in men was 9.2 +/- 8.1 and in women, 7.3 +/- 6.7 years. Hypertension was diagnosed in 19.8% of men and 18.1% of women. Diabetic retinopathy of any level was found in 55.4% of men and 45.7% of women. Mean glycohemoglobin in men was 9.6 +/- 2.1 and in women 9.5 +/- 2.2% (normal 4-8%). At baseline, proteinuria (1+ or more, by dipstick) was found in 24.7% of men and 9.6% of women, microalbuminuria (MA) in 84.4% of men and 63.8% of women. Quantitative albuminuria was abnormally high in 54.7% of men and 40.3% of women. In the 203 diabetics studied with 24 h urine collection for creatinine clearance, normal renal function was found in 69.1% of men and 47.5% of women, reduced renal function was found in 26% of men and 50% of women, renal insufficiency was diagnosed in 4.9% of men and 1.6% of women. One patient was on dialysis and in a subsequent follow up, we found that 2.3% of the patients had died of renal failure, six men (46-63 years) and a woman of 62 years. We conclude that DN is a very serious threat to this population. The high case fatality rate associated with this condition maintains a low prevalence. It is important to develop a program to diminish the frequency of this condition.

The insulin resistance syndrome in Mexico. Prevalence and clinical characteristics: a population based study.

The insulin resistance syndrome (IRS) is recognized as a harbinger of serious morbidity and high mortality. No published data on the prevalence of the IRS in the Mexican population exist. We estimated the prevalence of the IRS in an area that had 15,532 inhabitants, 3505 (22.6%) of whom were eligible (35-64 years of age, men and non-pregnant women). Interviews were obtained on 2810 (80.2%), a physical and laboratory examination with oral glucose tolerance test, insulin determinations and lipid profile was performed on 2282 individuals, 81.2% of those interviewed, 65.1% of eligibles. The IRS was defined as the coexistence of the triad: hypertension, glucose intolerance (diabetes or impaired glucose tolerance) and dyslipidemia (triglycerides > or = 200 mg/dl and HDL < 35 mg/dl). Using this diagnostic criteria the prevalence of IRS in the general population was 2.97% for men and 3.21% for women. In subjects with impaired glucose tolerance (IGT), the IRS was identified in 11.7%. In diabetics, IRS occurred in 13.7%. Subjects with IRS (IGT and diabetics) were significantly more obese (BMI 30 +/- 4.3 vs. 28.4 +/- 4.2 kg/m2 p < 0.001), had central upper body fat pattern distribution (sub/tri skinfolds 1.66 +/- 1.1 vs. 1.5 +/- 0.7 p < 0.02), (waist/hip circumferences 1 +/- 0.07 vs. 0.97 +/- 0.07 p < 0.001) and hyperinsulinemia fasting and post glucose load (25 +/- 17 vs. 15 +/- 13 p < 0.001, 157 +/- 92 vs. 85 +/- 72 p < 0.001, respectively). We conclude that the prevalence of IRS is high, individuals with IRS in Mexico have an anthropometric profile characterized by central, upper body obesity. A significant proportion of the patients with IGT and DM are at the highest cardiovascular risk.

[Alternatives against environmental pollution. The focus of the internist]. / Alternativas contra la contaminación ambiental. El enfoque del internista.

Potential pathogenesis from pollution depends on the kind of contaminant, its concentration, its duration in environment and on host's characteristics. Faced to the threat of medical consequences of pollution, it is necessary to be alert to recognize them, with an anticipated description. Two syndromes can be distinguished, one acute and the other chronic, that may be useful as reference for an eventual epidemiologic surveillance.

[Increase in neuroendocrine secretion granules in submaxillary and parotid glands in patients with non-insulin dependent diabetes mellitus]. / Aumento de los gránulos de secreción neuroendócrina en glándulas submaxilares y parótidas en pacientes con diabetes mellitus no dependiente de insulina.

The amount of neuroendocrine granules in microgranular cells of salivary glands were investigated in necropsies of 20 non-insulin dependent diabetics (NIDDM) and in 20 non-diabetic subjects with Grimelius and Fontana-Masson stainings. Granules in serous acini, and intercalated ducts were observed in both groups; however, a significant higher number of granules and microgranular cells were observed in NIDDM subjects as compared with non-diabetics. Both parotid and submaxillary glands were significantly heavier in NIDDM than in the non-diabetic group. These granules may be related to immunoreactive glucagon which has been found in submaxillary glands of rodents and might play a role in the pathogenesis of NIDDM. Further investigations should be performed to clarify whether these cells are the site of glucagon synthesis and also clarify the pathogenesis of NIDDM.

Influence of nopal intake upon fasting glycemia in type II diabetics and healthy subjects.

To assess if the acute hypoglycemic effect of nopal which occurs in diabetic patients also appears in healthy individuals, 500 g of nopal stems (O. streptacantha Lem.) were given orally to 14 healthy volunteers and to 14 patients with NIDDM. Serum glucose and insulin levels were measured at 0, 60, 120 and 180 minutes after nopal ingestion. A control test was performed with the intake of 400 ml of water. The intake of nopal by the NIDDM group was followed by a significant reduction of serum glucose and insulin concentration reaching 40.8 + 4.6 mg/dl (n = 14) (mean+SEM) and 7.8 + 1.5 uU/ml (n = 7) less than basal value, respectively, at 180 minutes. (P less than 0.001 vs control test). No significant changes were noticed in the healthy group as compared with the control test (P greater than 0.05). Acute hypoglycemic effect of nopal was observed in patients with NIDDM but not in healthy subjects, thus the mechanisms of this effect differs from current hypoglycemic agents.

Persistent fever as the only symptom of familial Mediterranean fever.

We describe a 54-year-old man who suffered from familial Mediterranean fever, but the fever has been the only symptom during a 10-year period. During this period, results of laboratory tests and roentgenographic studies were negative. On the basis of these findings we propose that familial Mediterranean fever can be included in the causes of persistent fever in patients with long periods of fever.

[Duration of the hypoglycemic action of Opuntia streptacantha Lem]. / Duración de la acción hipoglucemiante de Opuntia streptacantha Lem.

To assess the duration of Opuntia streptacantha Lem. hypoglycemic effect, two tests in fasting conditions, one with the intake of 500 g of broiled Opuntia stems and the other one with 400 ml of water as control, were performed in eight type II diabetics. Serum glucose levels were measured hourly during six hours. In the Opuntia test the decrease of serum glucose levels was more pronounced at the fourth hour (P less than 0.01 vs control test), serum glucose levels remained unchanged the following two hours. No significant changes on glycemia occurred in the control test. Difference between both tests was significant from the second to the sixth hour.

[Effect of fever on gastric emptying and on serum gastrin levels]. / Efecto de la fiebre sobre el vaciamiento gástrico y los niveles séricos de gastrina.

We studied the effect of fever on gastric emptying and serum gastrin 17 levels. 8 patients with fever and normal gastric emptying were selected. Blood samples were obtained for measuring serum gastrin 17. We used Tc99m scintiscanning to measure gastric emptying. Differences between fever and normal temperature were significant. Gastric emptying in fever was 118 +/- 54 minutes and 55 +/- 22 minutes for normal temperature (p less than .01). Serum gastrin was 47.7 +/- 13 pg/ml in normal temperature and with febrile patients was 30 +/- 5.7 pg/ml (p less than .002). We conclude that fever retards gastric emptying, perhaps independently of serum gastrin level.

[Effect of different doses of Plantago psyllium mucilage on the glucose tolerance test]. / Efecto de diferentes dosis de mucílago de Plantago psyllium en la prueba de tolerancia a la glucosa.

To assess the effect of different doses of Plantago psyllium mucilage on glucose tolerance test, four oral glucose tolerance tests were performed to eight healthy volunteers. Glucose load (75 g) was mixed with 0 (control test), 10.20 and 30 g of mucilage. Serum glucose levels were measured at 0, 30, 60, 120 and 180 minutes. Maximum peak of glucose at 30 minutes, and the area under the curve of glucose were significantly lower in the test with 20 and 30 g of mucilage than the tests with 0 and 10g. There was a significant relationship (r = 0.44 p less than 0.025) between the dose of P. psyllium mucilage and its attenuating effect of hyperglycemia.

[Hypoglycemic action of different doses of nopal (Opuntia streptacantha Lemaire) in patients with type II diabetes mellitus]. / Acción hipoglucemiante de diferentes dosis de nopal (Opuntia streptacantha Lemaire) en pacientes con diabetes mellitus tipo II.

To assess the relationship between the doses of O. streptacantha Lem. and its acute hypoglycemic action in diabetics, eight patients with type II diabetes mellitus were studied. Four test were performed to each patient with the intake of: (a) 400 ml of water, (b) 100 g (c) 300 g and (d) 500 g of broiled stems of O. streptacantha Lem. Serum glucose was measured at 0, 60, 120 and 180 minutes. Maximal decrease of serum glucose was noticed at 180 minutes, with a mean of 2.3, 10, 30.1 and 46.7 mg/dl less than basal value with 0, 100, 300 and 500 g respectively (P = NS, less than 0.05, less than 0.001 and less than 0.001 respectively). A significant direct correlation (r = 0.690, P less than 0.001) was noticed between the doses and the hypoglycemic effect.