Concentrations of Mercury and Other Inorganic Ions in Wet Precipitation Collected from a Mountain Mining Zone and an Urban Area in Central Mexico.

We measured and compared mercury (Hg) and other ions in rainwater collected in San Joaquin (mining zone) and Juriquilla (urban area), central Mexico, from 2009 to 2012. A total of 274 rainwater samples were collected and analyzed for pH, electrical conductivity, [Formula: see text] Cl-, [Formula: see text] Na+, K+, Ca2+, Mg2+ and Hg. Mercury concentrations in rainwater varied from 24.21 to 248.89 (x-bar = 86.97 ± 10.77) µg L- 1 in San Joaquin (mining zone) and 11.26 to 176.91 (x-bar = 81.51 ± 10.24) µg L- 1 in Juriquilla (urban area). Rainwater sample were collected over periods 1-3 days, depending upon precipitation frequency. Significant correlations (p < 0.05) were found between [Formula: see text] Cl-, [Formula: see text] Na+, K+, Ca2+, Mg2+ and Hg at the San Joaquin site. Significant correlations were obtained between [Formula: see text] Na+, K+, Ca2+, Mg2+ and Hg at the Juriquilla site. In order to determine if there were significant differences among each measured parameter in rainwater collected in San Joaquin and Juriquilla, Kruskal-Wallis test was applied to data. We emphasized that the distribution and concentrations of Hg and the studied ions in rainwater samples were affected by atmospheric dust and local meteorological conditions of wind-speed and direction.

Ultrastructural damage in Streptococcus mutans incubated with saliva and histatin 5.

OBJECTIVE: To study the ultrastructural alterations induced in Streptococcus mutans (ATCC 25175) incubated with saliva, saliva plus histatin 5 and histatin 5. METHODS: S. mutans incubated with saliva histatin 5 or a combination of both were morphologically analyzed and counted. The results were expressed as (CFU)ml-1. Ultrastructural damage was evaluated by transmission electron microscopy. Ultrastructural localization of histatin 5 was examined using immunogold labeling. Apoptotic cell death was determined by flow cytometry (TUNEL). RESULTS: A decrease in the bacteria numbers was observed after incubation with saliva, saliva with histatin 5 or histatin 5 compared to the control group (p<0.0001). Ultrastructural damage in S. mutans incubated with saliva was found in the cell wall. Saliva plus histatin 5 induced a cytoplasmic granular pattern and decreased the distance between the plasma membrane bilayers, also found after incubation with histatin 5, together with pyknotic nucleoids. Histatin 5 was localized on the bacterial cell walls, plasma membranes, cytoplasm and nucleoids. Apoptosis was found in the bacteria incubated with saliva (63.9%), saliva plus histatin 5 (71.4%) and histatin 5 (29.3%). Apoptosis in the control bacteria was 0.2%. CONCLUSIONS: Antibacterial activity against S. mutans and the morphological description of damage induced by saliva and histatin 5 was demonstrated. Pyknotic nucleoids observed in S. mutans exposed to saliva, saliva plus histatin 5 and histatin 5 could be an apoptosis-like death mechanism. The knowledge of the damage generated by histatin 5 and its intracellular localization could favor the design of an ideal peptide as a therapeutic agent.

Securing the appendiceal stump with the Gea extracorporeal sliding knot during laparoscopic appendectomy is safe and economical.

BACKGROUND: Laparoscopic appendectomy (LA) has become very popular. One criticism of this approach is the high cost of the disposable equipment such as the linear stapler. An alternative would be suture ligation of the appendiceal base. To prove the safety of the Gea extracorporeal sliding knot (GESK) for closure of the stump after LA, a retrospective study was conducted. METHODS: For this study, 63 LA procedures performed by one surgeon using the Gea knot (group A) were reviewed and compared with 63 LA procedures performed by two other surgeons (group B) using the linear stapler. The GESK is created with 0-prolene in the manner already described. The main variable was the presence or absence of blowout, leak, or fistula from the appendiceal stump. The secondary variables were abdominal abscess, wound infection, and need for readmission or reoperation. The results were analyzed using the appropriate statistical methods. RESULTS: Both groups were similar in terms of age, gender, and pathologic diagnosis. No patient in group A or B experienced a colonic fistula, stump blowout, or leak. In group A, one patient experienced interloop abscesses. There were two wound infections. In group B, one patient experienced a wound infection, and another patient had a wound dehiscence of the umbilical port, which required reoperation. No statistical differences were noted between the two groups. CONCLUSIONS: There are surgeons who routinely use sutures to secure the stump of the appendectomy. This study aimed to demonstrate that the GESK is as secure as the stapler for closure of the appendiceal stump. The GESK could be passed through a 5-mm trocar, potentially avoiding complications of a larger trocar site. The GESK seems to be an economic and safe alternative to the stapler.

Polymorphisms in candidate genes for type 2 diabetes mellitus in a Mexican population with metabolic syndrome findings.

The metabolic or insulin resistance syndrome, characterized by hypertension, dyslipidemia, glucose intolerance and hyperinsulinemia, may have genetic determinants. The insulin gene (INS), insulin receptor gene (INSR) and insulin receptor substrate 1 gene (IRS1) have been proposed as candidate genes. We examined eight polymorphisms in these genes in 163 individuals from Yucatan, Mexico; this population has a high prevalence of obesity, type 2 diabetes mellitus and dyslipidemia. Subjects were evaluated for body mass index (BMI) and blood pressure. Blood samples were collected to determine glucose, insulin, triglycerides and cholesterol levels, as well as for DNA isolation. Restriction fragment length polymorphisms in INS, INSR and IRS1 were identified by polymerase chain reaction and digestion with selected restriction enzymes. Among the eight polymorphisms analyzed, the PstI polymorphism in INS was significantly associated with hypertriglyceridemia and with the presence of at least one abnormality related to the metabolic syndrome (P=0.007 and 0.004, respectively). The MaeIII polymorphism in INS was associated with fasting hyperinsulinemia (P=0.045). In multilocus analyses including both INS polymorphisms, significant associations were seen with hypertriglyceridemia (P=0.006), hypercholesterolemia (P=0.031) and with presence of at least one metabolic abnormality (P=0.009). None of the polymorphisms in INSR or IRS1 was associated with any of these traits. These findings suggest that the insulin gene may be an important determinant of metabolic syndrome, and particularly of dyslipidemia, in this population.

Macroscopic and microscopic ionization constants of the thiol and amine groups in 1-methyl-4-mercaptopiperidine.

The acid dissociation constants of 1-methyl-4-mercaptopiperidine (pK(1) = 9.51, pK(2) = 11.33), the 1,1-dimethyl-4-mercaptopiperidinium ion (pK(A) = 9.59) and 1-methyl-4-(methylthio)piperidine (pK(B) = 10.18) have been determined potentiometrically in 3M sodium perchlorate (10% methanol) medium. The ultraviolet absorption of the mercaptide ion has been used to determine the relative proton affinity of the sulphur and nitrogen functions in 1-methyl-4-mercaptopiperidine under the same conditions, and its four microscopic constants (pK(a) = 9.49, pK(b) = 10.23, pK(c) = 11.34, pK(d) = 10.60) have been calculated; pK(A) has also been determined spectrophotometrically. From the results obtained, it can be concluded that the thiol group is more acidic than the amine group and that the Adams relation, K(a) + K(b) = K(1), holds very well when it is assumed that the spectrophotometric values for K(a), and K(b), can be replaced by K(A) and K(B) respectively.

[Polymorphism of the gene of vitamin D receptor and bone mineral density in postmenopausal women]. / Polimorfismo del gen del receptor de la vitamina D y densidad mineral ósea en mujeres posmenopáusicas.

BACKGROUND: Conflicting results have been reported on the association between restriction fragment length polymorphism at the vitamin D receptor (VDR) gene locus and bone mineral density (BMD). Population differences in environmental factors, such as calcium intake and calcidiol levels which have strong influence in BMD, may alter this association. PATIENTS AND METHODS: We analyzed the Bsml RFLP at the eight introm of the VDR gene in a population sample (n = 204) of postmenopausal Spanish women aged 50-65 years being seen clinically and studied calcium intake (dietetic questionnaire) and biochemical parameters (PTH and calcidiol). In parallel bone densitometry were measured in lumbar spine and proximal femur. RESULTS: We identified low BMD of the proximal femur in the BB group. This effect was not observed at other body locations. The calcium intake was lees than 500 mg/day in 60% of the studied population as calcidiol levels were lower than 10 ng/l in 36% of it. The total group population with normal calcium intake (> 1,000 mg/day) showed higher BMD (proximal femur and spine) than the group with low calcium intake, this variation not being observed in group BB alleles. Interestingly, we observed significant differences in BMD proximal femur between genotype groups BB versus Bb + bb when calcidiol levels were < 10 ng/l. Moreover, within the BB subgroup, those subjects with normal calcidiol levels have higher proximal femur BMD compared with those with low calcidiol levels. CONCLUSIONS: Our results indicate an effect of the VDR genotype on BMD proximal femur which is clearly influenced by calcium intake and calcidiol serum levels.

[Effectiveness of oral hypoglycemic drugs in the metabolic control of patients with gestational diabetes]. / Eficacia de los hipoglicemiantes orales en el control metabólico de pacientes con diabetes mellitus gestacional.

Gestational Diabetes is characterized by different degrees of glucose intolerance that produce a series of fetal and perinatal alterations. During many years, in those cases of gestational diabetes that did not respond to nutritional interventions, the use of insulin was a proven treatment to achieve metabolic control and thus a better perinatal outcome. At present, some new oral hypoglycemic drugs, from the family of sulfonylureas and biguanides, have been shown to be safe, of low cost, and apparently effective in the metabolic control of this disease. We review the publications that propose the use of oral hypoglycemic drugs for the metabolic control of gestational diabetes that does not respond to nutritional measures.

Obesidad y Embarazo / Obesity and Pregnancy

La mujer en edad reproductiva y especialmente la embarazada muestra cifras alarmantes de mal nutrición por exceso. El año 2009 el sobrepeso alcanzaba 32,0 por ciento y la obesidad 20,9 por ciento en embarazadas, según cifras del INE. La retención de peso a los seis meses post parto mostraba valores de 33,4 por ciento y 22,2 por ciento de sobrepeso y obesidad, respectivamente. En estas mujeres se observa mayor incidencia de aborto, mayor tasa de fracaso en técnicas de fertilidad y mayor incidencia de parto prematuro, preeclampsia, diabetes gestacional, tasa de cesáreas y macrosomía fetal. Por otra parte, los hijos de mujeres obesas tienen mayor riesgo de desarrollar obesidad y secuelas metabólicas. Variadas estrategias se han diseñado a objeto de regular el incremento de peso durante el embarazo, así como requerimientos específicos en el control prenatal, tendientes a un cuidado de las gestantes obesas. La cirugía bariátrica se presenta como una auspiciosa alternativa.

Women of childbearing age and pregnant women especially alarming figures show excess malnutrition. 2009 the figures reached overweight and obesity 32.0 percent 20.9 percent in pregnant women, according to figures from INE. and weight retention at six months postpartum showed values of 33.4 percent and 22.2 percent of overweight and obesity respectively. In these women have the largest incidence of abortion, higher technical failure rate of infertility and increased incidence of preterm delivery, preeclampsia, gestational diabetes, cesarean rate and fetal macrosomia Moreover, children of obese women at higher risk of developing obesity and metabolic consequences. Various strategies have been designed to regulate weight gain during pregnancy, as well as specific requirements for antenatal care. Bariatric surgery is presented as an auspicious choice.

Rol de las trombofilias en infertilidad: ¿juegan un rol? / The role of thrombophilias in infertility: do they have a role?

Las trombofilias son un grupo de enfermedades que favorecen la formación de trombosis, tanto arteriales como venosas, y han sido asociadas con diferentes complicaciones durante el embarazo, entre las cuales podemos mencionar: aborto recurrente, preclampsia, restricción de crecimiento intrauterino y muerte fetal in útero, entre otras. Recientemente, se ha sugerido una asociación entre trombofilias e infertilidad. Las mutaciones de la enzima Metilentetrahidrofolato Reductasa (MTHFR) y de Leiden se encuentran con mayor frecuencia en pacientes con infertilidad de causa desconocida, al compararlas con grupos controles. Durante la etapa de estimulación ovárica diversas trombofilias han sido vinculadas con la aparición de sindrome de hiperestimulación ovárica severo. Por último, las pacientes con historia de falla recurrente de implantación, luego de múltiples ciclos de fertilización in Vitro, demuestran una mayor prevalencia de trombofilias que las pacientes con éxito en dichas terapias. Este artículo presenta una revisión de las publicaciones relevantes que abordaran los distintos aspectos de la relación entre trombofilias e infertilidad hasta agosto de 2009. El objetivo es describir los estudios utilizados y sus implicancias en el manejo de la pareja infértil.

Thrombophilias are a group of conditions that favor the genesis of arterial/venous thrombosis. Several complications throughout pregnancy have been associated with trhombophilias, including recurrent spontaneous abortion, preeclampsia, intrauterine growth restriction and fetal demise. Recently, an asociation has been sugested between infertility and thrombophilias, involving diferent aspects of the infertile couple therapy. MTHFR and Leiden mutations can be found more frecuently in patients with diagnosis of unknown infertility when compared with control groups. During ovarian estimulation, thrombophilias have been linked with severe ovarian hiperstimulation syndrome. Furthermore, patients with recurrent implantation failure after in vitro fertilization therapy show a higher rate of thrombophilias than patients with succesful IVF therapy. A review of the relevant publications concerning the topic thrombophilia and infertility until august 2009 is presented in this article. The aim of this article is to describe the results of the studies and its relevance in the infertile couple treatment.

Characteristics of the movement of K+ across the mitochondrial membrane and the inhibitory action of Tl+.

The incubation of mitochondria in mixtures that contain phosphate, NaCl, oxidizable substrate, and ethylenediaminetetraacetate induces the efflux of K-+. This process depends on electron transport and on the cyclic movement of phosphate across the membrane. Sodium ions, Li-+, or Cs-+ to a smaller extent, are required for maximal release of K-+. Potassium ions do not induce net efflux of internal K-+, but instead prevent the Na-+-induced release of K-+. Significant K-+ influx takes place in K-+-depleted mitochondria through a process with characteristics which are almost identical with those in which K-+ release takes place. As Na-+ inhibits the uptake of K-+, it is suggested that the movement of K-+ across the membrane is controlled by the cationic environment. Thallous ion, at concentrations that do not affect oxidative phosphorylation, was found to be an effective inhibitor of the influx and the efflux of K-+. The inhibitory effect of Tl-+ seems to be specific for K-+ since it does not affect the movement of Na-+. Mitochondria bind 10 to 15 nmol of 204-Tl-+ per mg of protein through an energy-independent process.

In vitro antitumor activity of rebeccamycin analog (NSC# 655649) against pediatric solid tumors.

PURPOSE: This study determined the in vitro antitumor activity of a rebeccamycin analog (NSC# 655649) using tetrazolium/formazan (MTT) and clonogenic assays against established pediatric cell lines and solid tumor specimens obtained from children. MATERIALS AND METHODS: Tumor cells from 14 established cell lines and 20 patient specimens were exposed in vitro for 1 hour to NSC# 655649 at concentrations ranging from 0.015 to 15.0 microM. The cytotoxicity (IC50) of this agent against established cell lines was determined using both the MTT (cytotoxic) and clonogenic/soft agar cloning (cytostatic) assays. Tumor specimens from children undergoing biopsy or surgical resection were also evaluated in vitro against NSC# 655649 using the clonogenic assay. For studies using patient specimens, antitumor activity was measured by comparing the number of tumor colonies from NSC# 655649-treated cells with those from solvent-treated controls. RESULTS: These studies showed that the mean IC50S using the MTT and clonogenic assays using established solid tumor cell lines were 0.94 and 0.51 microM, respectively. In general, for cell lines tested using both types of assays, the clonogenic assay resulted in a smaller IC50. The overall in vitro responses (< or = 50% survival compared to controls) using patient tumor specimens and the clonogenic assay were 35% (1.5 microM), 60% (7.5 microM), and 80% (15.0 microM). Of the 9 patients with neuroblastoma, responses to NSC# 655649 were seen in 33% (1.5 microM), 58% (7.5 microM), and 92% (15.0 microM) of the specimens. Prior chemotherapy did not appear to adversely affect in vitro responses. CONCLUSIONS: NSC# 655649 appears to have broad antitumor activity in vitro against pediatric malignancies at drug concentrations achieved during adult phase I clinical trials. These studies support the further development of NSC# 655649 for solid tumors in children.

Molecular analysis of SRY gene in patients with mixed gonadal dysgenesis.

Mixed gonadal dysgenesis (MGD) includes a group of heterogeneous conditions consisting of a dysgenetic testis with a streak gonad. MGD is probably due to a disturbance in testicular determination/differentiation. The objective of this study is to analyze the SRY gene in MGD patients. A molecular investigation was undertaken in sixteen patients with this disorder in an attempt to determine mutations in SRY through polymerase chain reaction, single strand conformational polymorphism and direct sequencing. Eleven patients showed 45,X/46,XY and five 46,XY karyotype. Mutations in SRY gene were shown to be absent in these patients. This study confirms the findings of other studies. The etiology of MGD is heterogeneous, and cytogenetics mosaicism typically seen in these patients may be a cause of this condition, although, the presence of mutations in testicular organizing genes downstream of SRY is still to rule out.

MGI 114: augmentation of antitumor activity when combined with topotecan.

PURPOSE: 6-Hydroxymethylacylfulvene (HMAF; MGI 114; Irofulven) is a semisynthetic analogue of the mushroom toxin illudin S that has been shown to be a potent cytotoxic agent with an improved therapeutic index compared with its parent compound. The studies were conducted to evaluate the antitumor activity of MGI 114 as a single agent and in combination with topotecan against pediatric solid tumor cell lines and xenograft models. MATERIALS AND METHODS: In vitro studies were designed to determine the cytotoxic potential of MGI 114 using the MTT assay and 13 pediatric tumor cell lines. In addition, combination in vitro studies were performed with MGI 114 and topotecan to generate isoeffect plots. Single agent and combination in vivo studies were also performed using MGI 114 against rhabdomyosarcoma and neuroblastoma xenograft models. RESULTS: After a 1-hour exposure to MGI 114, the mean IC50 (+/-standard error of mean) for medulloblastoma, neuroblastoma, Ewing sarcoma/primitive neuroectodermal tumor, and rhabdomyosarcoma cell lines were 1.58+/-0.51, 1.60+/-0.82, 1.18+/-0.08, and 3.99+/-1.69 microg/mL, respectively. When tumor cells were exposed concurrently to MGI 114 and topotecan, evidence of synergy was observed in 10 of 12 (83%) cell lines. Single agent and combination in vivo studies with MGI 114 showed that this agent had substantial, and at times curative, antitumor activity against rhabdomyosarcoma and neuroblastoma xenograft tumors. CONCLUSIONS: These data suggest that MGI 114 has significant efficacy as a single agent in preclinical studies against pediatric tumors. In addition, based on previous reports and the results presented here, combining MGI 114 with topotecan appears to be an attractive approach to the treatment of pediatric malignancies. After completion of the pediatric phase I studies of MGI 114, consideration should be given to phase II single agent and phase I combination studies with a topoisomerase I inhibitor such as topotecan or irinotecan.

Eficacia de los hipoglicemiantes orales en el control metabólico de pacientes con diabetes mellitus gestacional / Effectiveness of oral hypoglycemic drugs in the metabolic control of patients with gestational diabetes

Gestational Diabetes is characterized by different degrees of glucose intolerance that produce a series of fetal and perinatal alterations. During many years, in those cases of gestational diabetes that did not respond to nutritional interventions, the use of insulin was a proven treatment to achieve metabolic control and thus a better perinatal outcome. At present, some new oral hypoglycemic drugs, from the family of sulfonylureas and biguanides, have been shown to be safe, of low cost, and apparently effective in the metabolic control of this disease. We review the publications that propose the use of oral hypoglycemic drugs for the metabolic control of gestational diabetes that does not respond to nutritional measures.

Ruptura hepática espontanea en hipertensión inducida por el embarazo / Spontaneous liver rupture in pregnancy induced hipertension

La ruptura de hematoma subcapsular hepático es una complicación muy infrecuente durante la gestación complicada con hipertensión, y se asocia con una alta mortalidad materna. Comunicamos el caso de una paciente de 34 años, que cursando embarazo de 29 semanas, presentó esta rara complicación y que evolucionó satisfactoriamente, practicándose terapia quirúrgica conservadora

Displasia esquelética letal: experiencia de nueve años y aproximación diagnóstica actual / Lethal skeletal dysplasia: experience of nine years and present diagnostic approach

Se presenta la experiencia de nueve años en el diagnóstico de las displasias esqueléticas letales mediante la descripción de seis casos clínicos. Se realiza una revisión actualizada del diagnóstico de estas patologías en el período antenatal.