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M Sandoval

Publications and source records attributed to M Sandoval.

At least 19 recordsLinked to original sources
PubMed1995

Role of inducible nitric oxide synthase expression and peroxynitrite formation in guinea pig ileitis.

BACKGROUND & AIMS: Inflammatory bowel disease is characterized by increased synthesis of nitric oxide. The aim of this study was to determine if inducible NO synthase (iNOS) was responsible for tissue injury, potentially via peroxynitrite formation, in the guinea pig model of gut inflammation. METHODS: Inflammation was induced in guinea pig ileum by intraluminal administration of the hapten trinitrobenzene sulfonic acid in 50% ethanol. iNOS gene expression was assessed by reverse-transcriptase polymerase chain reaction and Western blotting, immunohistochemistry was determined by its localization, and activity was inhibited with the specific inhibitor aminoguanidine administered via the drinking water for 7 days. Nitration of tyrosines was assessed by immunohistochemistry. RESULTS: In control animals, iNOS gene expression was minimal to absent, whereas, in hapten, inflammation-marked iNOS gene expression was evident from day 1 to 7. Nitrotyrosine and iNOS immunohistochemistry were colocalized, and positive staining was most intense in epithelia and neurons. Inhibition of NO formation prevented nitrotyrosine formation. Aminoguanidine inhibited the inflammatory response and restored morphology. CONCLUSIONS: The colocalization of tyrosine nitration with iNOS immunoreactivity suggests that iNOS may be responsible for tissue injury and the formation of NO-dependent nitrating species, potentially peroxynitrite. Inhibition of iNOS may afford a new therapeutic approach to the treatment of inflammatory bowel disease.

Amino Acid Sequence↗
PubMed1995

Role of metallothionein and cysteine-rich intestinal protein in the regulation of zinc absorption by diabetic rats.

Hyperzincuria and low Zn absorption in diabetic animals and humans have prompted speculation that diabetics are more susceptible to Zn deficiency. There is little information, however, describing the effects of diabetes on the biochemical mechanisms of intestinal Zn transport. We evaluated Zn absorption in streptozotocin-induced diabetic rats based on a model of Zn transport in which cysteine-rich intestinal protein serves as an intracellular carrier that is inhibited by metallothionein (MT). Apparent absorption and retention of Zn and Cu in rats fed a purified diet were measured in a balance study 15-17 d after induction of diabetes. The rate of 65Zn absorption from isolated intestinal segments, molecular distribution of 65Zn in mucosal cytosol, and tissue MT levels were measured on d 20-22. Food consumption, and thus Zn and Cu intake, by diabetic rats was twice that of controls. Although fractional absorption (percent) of Zn and Cu was lower in the diabetic rats, net absorption (micrograms/100 g body weight/d) was higher. The higher net absorption in the diabetic group was offset, however, by higher urinary excretion, so that Zn and Cu retention was similar in both groups of animals. Low fractional absorption is attributable to the down-regulation of intestinal Zn transport, as indicated by the lower rate of 65Zn absorption from isolated intestinal segments in the diabetic rats. Down-regulation of intestinal transport is in turn attributable to higher concentrations of intestinal MT, which resulted in more 65Zn in the mucosal cytosol bound to MT, an inhibitor of Zn transport, and less to cysteine-rich intestinal protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Prognostic value of the cellular expression of carcinoembryonic antigen (CEA) in gastric adenocarcinoma].

Fifty resected gastric adenocarcinomas were studied retrospectively to evaluate survival factors. Eleven different criteria were assessed using multivariate analysis. Only two criteria were significant: 1--cellular expression of carcinoembryonic antigen (p less than 0.0001 - CCR = 1.48) 2--intravascular or lymphatic tumor emboli (p less than 0.006 - CCR = 2.06). Thus, it is suggested that in addition to the various prognostic factors available to the surgical pathologist, the presence of cellular expression of carcinoembryonic antigen in tumor tissue will aid in predicting the prognosis of patients with gastric carcinoma.

Adenocarcinoma↗
PubMed1990

New approaches in the diagnosis of Taenia solium cysticercosis and taeniasis.

Taenia solium cysticercosis is now recognized as a priority in Mexico and a number of other developing countries, both in public health and in economic terms. Recognition of the problem has been greatly aided in recent years by new developments in molecular diagnostics. In this paper data are presented on ELISA for the detection of anti-cysticercus antibodies and of parasite antigens in patients with neurocysticercosis and in cysticercotic pigs. Also, several biological fluids were evaluated: cerebrospinal fluid (CSF), serum and saliva, all of which have proved useful. CSF is, however, the most appropriate for detection of antibodies and antigens in patients and serum in pigs. In addition, saliva may be especially used in epidemiological surveys. The electroimmuno-transfer blot technique (EITB) for antibody detection in patients and pigs has also proved highly sensitive and due to the use of an enriched fraction of glucoproteins, EITB is also highly specific. Cloned cDNA sequences from T. solium are now being assessed as an alternative source of antigens for immunodiagnosis. Two methods for the diagnosis of the adult stage of T. solium are also undergoing standardization. These are an ELISA for the detection of parasite antigens in fecal samples and DNA hybridization techniques for the detection of eggs in stools. Both assays have promising results and should now be assessed in larger numbers of clinical and epidemiological samples.

Animals↗
PubMed1989

Long-term correction of genetic defect of liver function in rat by transplantation of liver cells after ultraviolet irradiation.

Allograft rejection limits the survival and function of transplanted hepatocytes obtained from allogeneic donors. Presentation of donor antigens by antigen-presenting cells that express class II major histocompatibility antigens (MHC) carried in the graft has been implicated in allograft rejection. Ultraviolet-B (u.v.-B, 280 to 320 nm) irradiation and short-term culture have been shown to modify the function of antigen-presenting cells. In this study, we used u.v.-B irradiation (600 J/m2) of donor hepatocytes isolated from normal inbred Wistar RHA rats, followed by 16 to 20 hours of culture prior to transplantation into histoincompatible genetically analbuminemic rats (Nagase analbuminemic rats, NAR) by intraportal infusion of 10(7) viable hepatocytes. Isolated Wistar RHA hepatocytes without u.v.-B irradiation and/or culture, or NAR rat hepatocytes, were used as control. Survival and function of the transplanted hepatocytes were monitored by serial immunoassay of serum albumin in the recipients. Serum albumin concentration did not increase after transplantation of NAR rat hepatocytes. In NAR rats that received Wistar RHA hepatocytes, serum albumin levels increased from pre-transplantation levels of 0.025 to 0.05 mg/ml to 8 to 10 mg/ml. When freshly isolated liver cells were transplanted with or without u.v.-B-irradiation, but without culturing, serum albumin levels reached a maximum in two weeks and then progressively declined to pretransplantation levels. When the cells were not irradiated but cultured for 16 to 20 hours, elevated serum albumin levels persisted for six weeks, and then progressively declined to baseline concentrations. In contrast, when the isolated normal liver cells were u.v.-B-irradiated and cultured for 16 to 20 hours before transplantation, serum albumin levels persisted at 8 to 10 mg/ml throughout the duration of this study (32 weeks). Immunocytochemistry using anti-rat serum albumin (rabbit) immunoglobulin of liver tissue from NAR rats without transplantation or after transplantation with NAR liver cells showed immunostaining in less than one in 1000 cells. Four to 16 weeks after transplantation of u.v.-B-irradiated and cultured normal allogeneic hepatocytes, one to two per 100 hepatocytes stained positive for albumin. The results indicate that u.v.-B-irradiation followed by short-term culture of allogeneic rat hepatocytes prior to transplantation results in prolonged and perhaps permanent allograft acceptance by NAR rats.

Animals↗
PubMed1989

[Infections by anaerobes in children: frequency of isolation and antimicrobial resistance].

We studied the frequency of isolation and antimicrobial susceptibility of strict anaerobic bacteria isolated in a paediatric hospital. A total of 1,753 samples from purulent material and hemocultures were processed. One hundred and thirty strains were isolated from 95 children: 44 from 48 cases of peritonitis (91.7%), 2 from 8 brain abscesses (25%), 23 from 124 soft tissue abscesses (18.5%), 4 from 64 empyemas or lung abscesses (6.3%) and 22 from 1,509 hemocultures (1.5%). Mixed infection (anaerobic and aerobic bacteria) was detected in 38.5% of the cases; however, in peritonitis 81.3% of the cases showed mixed infection. The more frequently isolated bacteria were: Bacteroides (44.6%), Clostridium (19.2%), Fusobacterium (7.7%) and gram positive cocci (7.7%). Propionibacterium acnes was isolated in 15 specimens; however, most of them were considered as contamination. Bacteroides was isolated more frequently from patients with peritonitis (51.6%). The susceptibility to five antibiotics was tested in 124 strains using the method of serial dilutions in agar plates. The genus Bacteroides showed a high resistance to penicillin (73.1%), moderate to clindamycin (11.5%) and low to cefoxitin, chloramphenicol and metronidazole (6.8%, 2% and 5.8%). The rest of the anaerobic strains tested (other gram negatives and grampositives) were highly sensitive to all the antimicrobials tested, except for clindamycin (26.7% and 36.9% resistance, respectively). Cefoxitin, chloramphenicol and metronidazole had the lower CMI50 and CMI90 for the genus Bacteroides; and for the rest of the bacteria, penicillin had the highest activity (CMI90 less than 0.025). Since the frequency of isolation of anaerobic bacteria in children with severe infections, presumably originated from the digestive tract, paranasal sinus and middle ear is high, anaerobic cultures must be practiced in these patients. Empiric antimicrobial treatment should also be started. This treatment should be with penicillin when the probability of isolation of Bacteroides is low (infections in the face, neck, thorax and soft tissues) and with metronidazole in intraabdominal infections. Because of the severity and probable etiology of brain abscesses, treatment with penicillin and chloramphenicol or metronidazole is recommended in these cases.

Anti-Bacterial Agents↗
PubMed1988

Comparative analysis of human and porcine neurocysticercosis by computed tomography.

Human and porcine cases of neurocysticerosis were compared by computed tomography in regard to the morphological characteristics of the parasites and the impact of the infection on the brain. In pigs and young people many parasites were usually found, but this was seldom the case in adult humans. These parasites were small and located mainly in the parenchyma and the subarachnoid space; no calcified cysticerci were found. In contrast, in adult humans cysticerci were heterogeneous in appearance and distribution. The brain of the pigs showed no evidence of inflammatory reaction while young people had oedema, enhancement and hydrocephalus; in contrast, adults showed diverse tomographic characteristics of brain response. Thus, the disease has at least 2 different forms. It may be mild with short development and parasites of similar appearance, as occurs in young hosts. In contrast, a long lasting disease occurs in adults, with diverse tomographic, neurological and parasitological features.

Adolescent↗
PubMed1986

Reliable serology of Taenia solium cysticercosis with antigens from cyst vesicular fluid: ELISA and hemagglutination tests.

New levels of reproducibility and sensitivity have been achieved in the detection of anticysticercus antibodies in human sera by using cysticercus vesicular fluid as the source of antigens for both ELISA and hemagglutination assays. Reproducibility both between tests on a serum and between similar sera was significantly improved over typical results using antigens from whole parasite extracts. Sera collected from uninfected individuals in endemic areas gave somewhat elevated values over those collected in nonendemic areas. This necessitated the use of a higher threshold in endemic areas to avoid false positives. With the threshold appropriate for a nonendemic area, both ELISA and hemagglutination were sensitive enough to detect infection in 95% of cases. With the threshold value for sera from an endemic area, these sensitivities were reduced to 80%-90%. A prominent 103-Kd protein of vesicular fluid, not related to antigen B, elicited the strongest antibody response in neurocystercotic patients.

Antibodies↗
PubMed1983

Intraventricular cysticercosis.

The authors review their experience with 21 cases of intraventricular cysticercosis, which corresponded to 28% of all cases of neurocysticercosis in their department during an 18-month period. The surgical approach depends on the cyst's location; one uses the transcortical microsurgical approach to reach the lateral ventricles, the transcortical or transcallosal approach to reach the 3rd ventricle, and direct exploration to reach the 4th ventricle. Cysticercus cysts should be removed because they may produce acute or chronic hydrocephalus and, if the parasite dies within the ventricles, it will generate an inflammatory reaction with local and generalized ventriculitis, which produces irreversible neurological damage.

Adult↗
PubMed1982

The seagull incision in posterior cervical lift: indications, limitations, and surgical technique.

A seagull incision in the posterior scalp as used by us for the past 15 years for the correction of flaccidity in the posterior and anterior lower neck regions through a posterior cervical lift has been described in detail with its advantages, indications, and limitations. In our experience, the posterior cervical lift has little or no effect in correcting flaccidity in the upper anterior neck region, and therefore, this procedure should not be routinely performed in all cases of rhytidoplasty. One has to be highly selective in performing this procedure.

Esthetics↗
PubMed1980

Umbilical reconstruction with secondary abdominoplasty.

Umbilical loss is not an uncommon problem following primary abdominoplasty done by an improperly trained surgeon who either sacrificed the umbilicus or lost it through postoperative complications. Deep psychological trauma with mental depression is often the result of such an amputation and is also the main concern of the patient seeking help. There are usually other secondary sequelae, such as residual cutaneous and musculoaponeurotic flaccidity, asymmetrical scarring with dog-ears at either extremity, and fatty bulges that may not bother the patient. In the past, umbilical reconstruction has been handled as an isolated procedure. We have tried to alleviate this condition along with the other residual deformities by doing complete secondary abdominoplasty. Along with the technical details of umbilical reconstruction, 2 such case reports with preoperative and postoperative results are presented.

Abdomen↗
PubMedDate not supplied

Comparison of two assays (EIA and EITB) and two samples (saliva and serum) for the diagnosis of neurocysticercosis.

The enzyme immunoassay (EIA), standardized with a crude extract, and the enzyme-linked immunoelectrotransfer blot assay (ETIB) with glycoprotein antigens, were compared by using saliva and serum in the search for specific antibodies against Taenia solium larvae, for the diagnosis of neurocysticercosis. Saliva was slightly more sensitive in EIA (82.1%) than serum (74.1%). In EITB serum was far more sensitive (100%) than saliva (70.4%). The use of EITB with serum is thus an excellent choice for diagnosis of clinical cases of neurocysticercosis, while EIA using saliva represents a useful combination for diagnosis and, especially, epidemiology, because saliva is easily obtained by a painless and non-invasive procedure and the technique is simpler to perform. Furthermore, cross-reactivity of EIA with Echinococcus does not interfere in countries like Mexico where human hydatid disease is not present.

Animals↗
PubMedDate not supplied

[Mitral valve replacement in children and in adolescents. Surgical indication and long-term results in 86 cases].

1. The authors present 86 children and adolescents with rheumatic heart disease of the Pediatric Cardiology Service of the Instituto Nacional de Cardiologia who received valve replacements in the period between September, 1964 and April, 1973, a series which is more numerous and of longer follow-up than any published up to the present 2. In order to obtain comparable results, patients with mitral heart disease of other origen and aortic replacement as well as those subjected to double or triple exchange, were omitted from the study. 3. The symptomatology, the presence of compensated heart failure, the progression of cardiomegaly, the radiologic and electrocardiographic changes, the presence of atrial fibrillation, the mean venocapilary, pulmonary arter, and left right ventricle telediastolic pressures, the pulmonary resistence figures and the results of cineangiocardiography were the fundamental elements used to establish the surgical indication. 4. None were operated with clinic or laboratory data suggesting rheumatic activability. The shortest period between the last bout of rheumatic fever and surgery was 10 months. 5. The clinic improvement was remarkable. Half of the cases receiving digitalis and diuretics were released without this prescription and only 10% continue to take digitalis. With the exception of five patients, the physical capacity is normal and most play sports. The postoperatory radiologic and electrocardiographic changes were remarkable, most were obtained a few months after surgery. With the exception of one case, atrial fibrillation disappeared (in 58% before six months in a group of 31 patients). 6. The later complications attributed to the valve replacement as well as the 15 deaths in the total lot were analyzed. It was pointed out that the hospital death rate was 12.6% and the later was 5.3%, extraordinarily low figures if it is taken into account that the material corresponds to nine years of work and the problems inherent to the initial period are included. It gains still greater importance if compared to the series published up to the date. The global mortality rate of 17.9% is small in relation to the only comparable publication, -30 and if only the results of the last three years are compiled (61 cases equals 70 of the series), the global death rate was 9.8%. 7. It was noted that the results are due to the system adopted for establishing the surgical indication, to the good state of the myocardial fiber...

Adolescent↗