Sensor fault detection and isolation via high-gain observers: application to a double-pipe heat exchanger.

This paper deals with fault detection and isolation (FDI) in sensors applied to a concentric-pipe counter-flow heat exchanger. The proposed FDI is based on the analytical redundancy implementing nonlinear high-gain observers which are used to generate residuals when a sensor fault is presented (as software sensors). By evaluating the generated residual, it is possible to switch between the sensor and the observer when a failure is detected. Experiments in a heat exchanger pilot validate the effectiveness of the approach. The FDI technique is easy to implement allowing the industries to have an excellent alternative tool to keep their heat transfer process under supervision. The main contribution of this work is based on a dynamic model with heat transfer coefficients which depend on temperature and flow used to estimate the output temperatures of a heat exchanger. This model provides a satisfactory approximation of the states of the heat exchanger in order to allow its implementation in a FDI system used to perform supervision tasks.

[Factors of risk of bacterial vaginosis]. / Factores de riesgo asociados a vaginosis bacteriana.

OBJECTIVES: To recognise factors in the host that might condition the appearance of the bacterial vaginosis (BV) syndrome, whether gynae-obstetrical factors, habits of sexual conduct, hygiene, or other factors. DESIGN: Cross-sectional, observational study. SETTING: The study was conducted from January 2002 to June 2003 in the Primary Care Dr. Jose Castro Villagrana Community Health Centre at Tlalpan, Mexico City. PARTICIPANTS: 968 patients with an active sexual life who had not taken antibiotics for at least 15 days before the study and who were not menstruating at the moment of taking a swab, 859 of whom had a diagnosis of cervico-vaginitis and 109 had no symptoms. MAIN MEASUREMENTS: Confidential questionnaire and a cervical-vaginal culture. The Amsel criteria were used to make the diagnosis of bacterial vaginosis. RESULTS: There was 32.9% prevalence of BV. There was a statistically significant association with factors such as age, start of active sexual life, the number of sexual relations per week, the number of sexual partners, and pregnancy. CONCLUSIONS: Bacterial vaginosis is the main cause of infectious processes in the vagina. Its appearance appears to be linked to factors involving sexual transmission. Interventions to reduce its prevalence and complications are recommended.

Presence of keratinophilic fungi with special reference to dermatophytes on the haircoat of dogs and cats in México and Nezahualcoyotl cities.

In order to study the presence of keratinophilic fungi with special reference to dermatophytes on the coat of dogs and cats living in the cities of Mexico and Nezahualcoyotl in the Metropolitan area of Mexico City, two hundred samples were collected from dogs and one hundred from cats by using the MacKenzie's tooth brush technique, they were processed by routine mycological methods for dermatophyte fungi, results were analyzed by means of the statistical packages SAS. There were isolated 67 and 90 keratinophilic strains from cats and dogs samples, respectively. The most commonly fungi isolated in pure culture in this study were Chrysosporium spp (25%), followed by Trichophyton terrestre (22%), Microsporum gypseum (5%), M. canis (4%), as well as mixed cultures like Chrysosporium spp. & M. gypseum (2%) and T. terrestre & T. mentagrophytes (1%). Keratinophilic fungi were found in higher numbers in the cat haircoat (67%) than in the dog's (45%) and the same was true with regard to dermatophytes with 12 isolates out of a 100 samples in cats and 7 Isolates out of 200 samples from dogs. This may represent a health risk for humans in contact with a dermatophyte infected cat or dog.

[Vaginal candidiasis: diagnosis and treatment in a primary care clinic]. / Candidiasis vaginal: diagnóstico y tratamiento en el primer nivel de atención médica.

OBJECTIVE: To assess the frequency of Candida species others than Candida albicans isolation, in patients with chronic as well as relapsing vaginitis. To analyze the clinical pictures and the treatments routinely employed in patients with Candida albicans infection, compared to those with other Candida species infection, in a Primary Care Clinic. DESIGN: Prospective, comparative, transverse study. SETTING: Primary health center from January, 1995 to May, 1997. MATERIAL: Two hundred and thirty four women (234) in ages between 16 and 55 years, with cervicovaginitis and a positive culture to any species of Candida, were the subject of the present study. RESULTS: From the total of 234 patients studied, 142 (60.5%) were infected by Candida albicans and 92 (39.5%) by other Candida species; no difference in symptomatology was recorded in both groups. Nistatine alone or combined with imidazole derivatives were the antimycotics more commonly employed, with Candida albicans resistance of 9.6% in the first case and 11.2% in the second one. CONCLUSIONS: It is stressed the importance that has the identification of Candida species causing vaginitis. It is also acknowledged the well handled treatment, despite of the species to be treated.

Isolation of Chlamydia psittaci involved in abortion of goats in Mexico: first report.

A group of 35 healthy adult goats ranging from two to six years old were bought from a chlamydiosis and brucellosis-free flock; they were vaccinated against Brucella melitensis with Rev1 vaccine at reduced doses, and one month later placed in isolation units. The animals were one month pregnant at the moment of purchase, and during the third month of pregnancy 10 out of the 35 dams aborted. Necropsy of the aborted fetus and examination of the foetal membranes was performed where no macroscopic lesions were observed. Abomasal liquid, foetal lung and liver, and placenta samples were taken for bacteriological analysis while sera from the goats that aborted was collected for serological investigation. Chlamydia psittaci was isolated in all cases, while no Brucella was detected. All sera reacted positive to anti-Chlamydia antibodies by the indirect immunofluorescence test. This represents the first report of Chlamydia psittaci isolation from cases of goat abortion in Mexico.

[Current state of conservative management of ectopic pregnancy]. / Estado actual del manejo conservador del embarazo ectópico.

The ectopic pregnancy constitutes a disease that require the most diagnostic accuracy, not only for the biologic importance of its clinical manifestations, but for the sequelae of its treatment too, in relation with the fertility of a patient frequently affected with infertility so far. The increase in its frequency, by multiple factors, including treatment of infertility itself and Assisted Reproduction techniques, make the clinician must be alert and have availability of all diagnostic tools for the establishment of an oportune and conservative treatment, directed to prevent an acute alteration of the hemostasis and a shadowy reproductive future. The present review of the literature about the conservative management of the ectopic pregnancy let us have to know the criteria neccessary for giving the optimum treatment to our patients and offering them a better reproductive future.

[Preoperative management of uterine leiomyomatosis using pituitary gonadotropin-releasing hormone analogues]. / Tratamiento médico preoperatorio de leiomiomatosis uterina con análogos de hormona liberadora de gonadotropinas hipofisarias.

Uterine leiomyomatosis shows a frequency from 25 to 30% in reproductive age women. Traditional treatment is hysterectomy or myomectomy independently from fertility wishes of the woman. Its growth has been associated to estrogenic activity. Because of this, several substances have been used to diminish tumour size, pre-operatively. The use of analogues of liberating hormone of hypophysiary gonadotropins (GnRH), given to favor surgical technique, to diminish trans-operative bleeding and to avoid blood transfusions. Clinical efficiency of the use of nafarelin acetate in women with uterine leyomiomatosis, pre-operatively during three months, was studied in this paper. The study was prospective, comparative, blind and with longitudinal measurements. Twenty eight women were included. Group I (n = 13) and Group II (n = 15) control without treatment. Observation units included FSH, LH, E2, BHC, HCT, USG basal, 30, 60, 90 days. Results showed a diminution of more than 80% of the initial uterine volume, and of 30% of the myomas independently measured. Side effects, tolerance and efficacy of the used compound, are mentioned.

[Evidence of luteotropic activity of chorionic gonadotropin in patients with controlled ovarian stimulation]. / Evidencia de actividad luteotrópica de la gonadotropina coriónica en pacientes sometidas a estimulación ovárica controlada.

Fourty seven women with infertility with controlled ovarian hyperstimulation with menotropins, were studied to corroborate the evidence of the luteotropic activity after the administration of human chorionic gonadotropin (hCG). They were divided in two groups: Group 1; 23 patients with (hCG). Group 2; 24 patients without (hCG). Seric progesterone level was determined at the 21 day of the cycle in both groups, with a significant difference (P < 0.05). We report 7 pregnancies; 5 in Group 1, and 2 in Group 2.

[Pyo-ovary as a complication of transvaginal follicular aspiration]. / Pioovario como complicación de aspiración folicular por vía transvaginal.

Patient with primary sterility; antecedent of tubal surgery and damaged tuboperitoneal factor; she was programmed for in vitro fertilization with embryo transference. She had ovarian hyperstimulation with pure FSH and menotropins; follicular aspiration, via vagina with ultrasonographic guidelines. Seven days after, she presented with colic pain at left iliac region a hard, painful mass was found at left iliac region. Uterus deviated to the right, painful to movement; left vaginal cul de sac increased in volume and left adnexal tumor, without limits; left pararectal tumor. Exploratory laparoscopy was done, with pelvic abscess drainage, 10 to 12 cm, and left oophorectomy; the diagnosis was left pyo-ovary. Normal evolution.

[The ovarian hyperstimulation syndrome. Institutional experience]. / Síndrome de hiperestimulación ovárica. Experiencia institucional.

Thirty patients with OHS were analyzed; all of them had to be hospitalized. There was no difference as to sterility time and syndrome appearance. The use of menotropines caused more frequently the syndrome. There was multiple pregnancy in 33%. Abortion incidence was 16%. As the etiology is unknown there is not an adequate treatment, and care is for maintenance. Prevention is the best option.

[The evaluation of the usefulness of ultrasound independent of estradiol as a prognostic criterion for ovular capture and maturity. A comparative double-blind study]. / Evaluación de la utilidad del ultrasonido independiente de estradiol como criterio pronóstico para captura y madurez ovular. Estudio comparativo doblemente ciego.

One hundred and twenty women were studied which had primary or secondary sterility, and underwent into the GIFT or IVF-ET program at the INPer. They were divided in two groups. Group I had 96 women in which only was taken in account the follicular development measured by vaginal ultrasound to decide continuation or cancellation, in this group estradiol serum levels determination was done, but it was not used for decision making; group II had 24 women in which estradiol was taken in account in addition with ultrasound. There were no differences in the number of follicles seen by ultrasound neither in the estradiol serum levels between the groups. Correlation coefficients between follicles seen by ultrasound and retrieved oocytes and mature oocytes, thus partial correlation coefficients for follicles seen by ultrasound plus estradiol serum levels and retrieved oocytes and captured oocytes were higher in group I in all days with the exception of day 10 in which they were similar. By the aforementioned in can be concluded that in this group of patients the ultrasound was the most reliable variable to give a quantitative and qualitative prognostic of oocyte retrieval.

[Obstetrical analysis of pregnancies obtained by GIFT or FIV at the National Institute of Perinatology]. / Análisis del comportamiento obstétrico de los embarazos logrados por GIFT y FIV-TE en el Instituto Nacional de Perinatología.

The obstetrical outcome of 47 pregnancies which was achieved by assisted reproduction techniques was analyzed. 38 were achieved by GIFT and 9 by IVF-ET. In both series we found that the analyzed parameters are similar to those described by other groups. But in discordance with Angle-Saxon groups, in Latino-American series the principal delivery way was by cesarean section.

[Ovarian hyperstimulation syndrome. Current concepts]. / Síndrome de hiperestimulación ovárica. Conceptos actuales.

The ovarian hyperstimulation syndrome is the most severe iatrogenic complication of ovarian stimulation. Currently, the number of women receiving drugs for ovulation induction has markedly increased with the advent of different medically assisted reproduction programs. Consequently, this potentially life-threatening situation has become a frequent clinical problem. Since its pathophysiology is poorly understood, it is the clinician's responsibility to ensure its accurate prevention, prediction and active management. Although severe and critical ovarian hyperstimulation syndrome may be not completely avoided, it is the responsibility of the clinician to be aware of an early recognition of high-risk factors and make a judicious prevention to reduce the complication and sequelae of this iatrogenic syndrome. The present work offers an overview of the current world literature on ovarian hyperstimulation syndrome.

[Biological process in patients having been impregnated through GIFT or IVF-ET. Clinical experience]. / Comportamiento biológico en pacientes que lograron embarazo por GIFT o FIVTE. Experiencia institucional.

There were analyzed in a retrospective way the results of pre-retrieval hormonal levels as well as the number of retrieved oocytes, mature oocytes and transferred embryos in three groups of patients (2 GIFT, 1 IVF-ET) which achieved a pregnancy, and were matched with groups with no pregnancy. There were no statistically significant differences in most of the analyzed parameters, by the aforementioned we can suppose that pregnancy depends of endometrial quality and in this moment we are not able to modify it satisfactorily.

[The functional ovarian reserve in assisted reproduction. A clinical dilemma]. / Reserva ovárica funcional en reproducción asistida. Dilema clínico.

The response to supraphysiological ovarian stimulation in Assisted Reproduction (particularly FIV-TE and GIFT) may be very heterogeneous, despite the fact that selected patients have clinical and paraclinical characteristics very homogeneous. Highly significant differences, were found, in two groups of patients with similar clinical characteristics, who were stimulated with the same scheme. Group I (Adequate response = 22 patients) and Group II (Inadequate response = 13 patients), regarding to basal seric levels of FSH (P = 0.007) and to quality of follicular response (P = 0.000). These results suggest that quality of response to supraphysiological ovarian stimulation, may reflect a "Functional ovarian reserve" and that this can be predicted (partially) with basal seric levels of FSH; but, may be, the inadequate response, paradoxical to certain point, would not represent an ovarian failure or a resistant ovarian syndrome, incipient or transitory during the reproductive age?

[An orthotopic pregnancy after 2 ectopic ones. A report of 2 cases and review of the literature]. / Embarazo ortotópico posterior a dos ectópicos. Informe de dos casos y revisión de la literatura.

The prognosis as to reproduction of patients with two surgical procedures for the tubes for managing ectopic pregnancy, is very bad. Two cases of live intrauterine pregnancy, after two tubal pregnancies surgically managed, are presented. Salpingectomy and salpingostomy were carried out in one patient, and salpingostomy and salpingectomy in the other one. In world literature there are only 23 reported cases, since 1947.

[Corpus luteum defect. Analysis of 30 cases in clinical pregnancy]. / Cuerpo lúteo deficiente. Análisis de 30 casos con embarazo clínico.

Deficient corpus luteum (DCL) is an ovulatory dysfunction little defined but real. It is said that is frequency is 3 and 10% of sterile couples and 30 to 40% of habitual abortion. Is part of the group of ovulatory aberrations together with in situ luteinization and syndrome of not broken luteinized folicle. The diagnosis is based in endometrial morphology and progesterone determination. The objective of this work is to analyze 30 cases of DCL that achieved pregnancy. The diagnosis was done based on low determination of progesterone in serum, biopsy of irregular or indysphase endometrium and all the factors, remaining normal of esterility. Average age of patients was 36 years and for sterility 3.1. Treatment consisted in clomiphen cytrate (CC) administration 100 mg daily of hCG in 21 cases, CC only in eight cases and associated to bromocriptine in one case (concomitant hyper-prolactinemia); 26 pregnancies went to term, seven of them with support of exogenous progesterone the first weeks. There were three abortions and an ectopic one. It is concluded that with a complete study of sterility that only shows low seric progesterone and/or endometrium in dysphase or irregular, the diagnosis of DCL is probable and should be treated first with CC plus hCG. The evolution of pregnancies is normal and according to these results is little acceptable the use of progesterone as a support in pregnancy.

[Heterotopic pregnancy in intrauterine insemination. Presentation of a case]. / Embarazo heterotópico con inseminación intrauterina. Presentación de un caso.

The heterotopic (ectopic and orthotopic simultaneous) pregnancy shows a frequency of 1 to 15,000 to 1 to 30,000 gestations. The clinical diagnosis is difficult due to the lack of precise indicators, as to diagnose an intrauterine pregnancy eliminates the possibility of ectopic pregnancy. The methods of Assisted Reproduction seem to be factors that have influenced on the increment of this type of gestations. A case of a 32 year patient with primary sterility by pelvic adhesions process, that was surgically treated, as there was no pregnancy after surgery, she was given intrauterine insemination with her husband's semen (IU) pregnancy was obtained, determined at 15 days of menstrual lack by presence of subunit B of HCG in serum and vaginal ultrasound that confirmed gestational sac. One month after she presented at Urgencies with an acute abdominal condition; laparotomy was done and salpingectomy was carried out for ruptured tubal pregnancy confirmed by histopathology. The evolution on intrauterine pregnancy was normal culminating with cesarean section at week 35 by inminence of eclampsia/Mother and child in good conditions.

[Presentation of a mathematics formula of duplicated times of estradiol predictive for ovular harvesting]. / Presentación de una fórmula matemática de tiempos de duplicación de estradiol pronóstica para captura ovular.

30 patients were studied, that were included in the IVF program of the INPer. The estradiol response was studied and was correlated with the number of retrieved oocytes. The previously known E2 values considered as indicative for cancellation did no were observed in this series, and there are proposed new ones, also prognostic criterion for oocyte retrieval are proposed.