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S Delgado

Publications and source records attributed to S Delgado.

At least 19 recordsLinked to original sources
PubMed2006

Cloning, sequencing, and expression of the amelogenin gene in two scincid lizards.

Our knowledge of the gene coding for amelogenin, the major enamel protein, is mainly based on mammalian sequences. Only two sequences are available in reptiles. To know whether the snake sequence is representative of the amelogenin condition in squamates, we have studied amelogenin in two scincid lizards. Lizard amelogenin possesses numerous conserved residues in the N- and C-terminal regions, but its central region is highly variable, even when compared with the snake sequence. This rapid evolution rate indicates that a single squamate sequence was not representative, and that comparative studies of reptilian amelogenins might be useful to detect the residues which are really important for amelogenin structure and function. Reptilian and mammalian enamel structure is roughly similar, but no data support amelogenin being similarly expressed during amelogenesis. By performing in situ hybridization using a specific probe, we showed that lizard ameloblasts express amelogenin as described during mammalian amelogenesis. However, we have not found amelogenin transcripts in odontoblasts. This indicates that full-length amelogenin is specific to enamel matrix, at least in this lizard.

Ameloblasts↗
PubMed2005

Synthesis of three marine natural sesterterpenolides from methyl isoanticopalate. First enantioselective synthesis of luffolide.

[Reaction: see text]. The synthesis of three marine sponge metabolites, luffolide (4), 5, and 6, are described for the first time, establishing the absolute configuration of these compounds. The key intermediate, aldehyde 17, was obtained from methyl isoanticopalate, 11. The addition of 3-furyllithium to 17 and subsequent photochemical oxidation give the gamma-hydroxybutenolide 5 and its epimer at C-16. Sesterterpenolide 6 is obtained by dehydration of 5. From the key aldehyde 17, luffolide (4) was obtained in six steps.

Aldehydes↗
PubMed2005

Impact of hospital case volume on short-term outcome after laparoscopic operation for colonic cancer.

BACKGROUND: High hospital case volume has been associated with improved outcome after open operation for colorectal malignancies. METHODS: To assess the impact of hospital case volume on short-term outcome after laparoscopic operation for colon cancer, we conducted an analysis of patients who underwent laparoscopic colon resection within the COlon Cancer Laparoscopic or Open Resection (COLOR) trial. RESULTS: A total of 536 patients with adenocarcinoma of the colon were included in the analysis. Median operating time was 240, 210 and 188 min in centers with low, medium, and high case volumes, respectively (p < 0.001). A significant difference in conversion rate was observed among low, medium, and high case volume hospitals (24% vs 24% vs 9%; p < 0.001). A higher number of lymph nodes were harvested at high case volume hospitals (p < 0.001). After operation, fewer complications (p = 0.006) and a shorter hospital stay (p < 0.001) were observed in patients treated at hospitals with high caseloads. CONCLUSIONS: Laparoscopic operation for colon cancer at hospitals with high caseloads appears to be associated with improved short-term results.

Aged↗
PubMed2004

Laparoscopic-assisted approach in rectal cancer patients: lessons learned from >200 patients.

BACKGROUND: The applicability of laparoscopic surgery in the treatment of colorectal diseases is still controversial. Early reports on laparoscopic-assisted colectomy in patients with colon cancer suggested that it minimizes surgical trauma, decreases perioperative complications, and leads to a more rapid recovery. To our knowledge, no previous studies have compared the laparoscopic vs the open approach in rectal cancer. The aim of this paper was to assess the results of laparoscopic techniques in patients with rectal cancer. METHODS: From March 1998 to February 2003, all patients admitted to our unit with adenocarcinoma of the rectum were evaluated for surgery by the laparoscopic approach. RESULTS: A total of 220 patients with a mean age of 67.3 years were included in the study. One hundred thirty patients (59%) were treated with neoadjuvant chemoradiotherapy. In >75% of the patients, a surgical procedure with sphincter preservation was performed. The rate of conversion to the open approach was 20%. Ten patients had intraoperative complications. Fifty-eight patients (26.3%) developed postoperative complications. The length of hospital stay was 6.8 days. The distribution of tumor stages was as follows: stage I, 16.81%; stage II, 33.6%; stage III, 26.36%; stage IV, 19.09%. The mean number of lymph nodes was 13.8. The incidence of local relapse was 5.3%, with a follow-up of 18 months. CONCLUSION: Laparoscopic surgery can be safely performed in patients with adenocarcinoma of the rectum with good short-term results. Randomized controlled trials are needed to confirm these results.

Adenocarcinoma↗
PubMed2004

Laparoscopic-assisted colectomy in patients with liver cirrhosis.

BACKGROUND: Nonhepatic abdominal surgery, and especially colorectal surgery, is associated with high rates of morbidity and mortality among cirrhotic patients. With proper patient selection and preoperative optimization of the patient's condition, laparoscopic-assisted colectomy could become effective and safe for patients with compensated liver cirrhosis. The aim of this study was to evaluate the safety and feasibility of minimal-access surgery in these patients. METHODS: Between September 1993 and March 2003, 820 patients underwent laparoscopic-assisted colectomy at our hospital. We studied all patients with liver cirrhosis who underwent this operation. RESULTS: Seventeen patients with cirrhosis were included in the study. Twelve were Child's A and five were Child's B. The mean operative time was 150 min (ranges 75-280), mean estimated blood loss was 245 ml (ranges 100-250). The conversion rate to open surgery was 29% (five patients). Median length of hospital stay was 5 days. The morbidity rate was 29% (five patients). There were no anastomotic leaks or operative-related deaths. The median follow-up was 21 months. CONCLUSIONS: Laparoscopic-assisted colorectal surgery can be performed in compensated cirrhotic patients with low morbidity and mortality. Adequate patient selection and expertise in advanced minimal-access surgery are essential to obtain such good results.

Adenocarcinoma↗
PubMed2004

Transportation of reclaimed wastewater through a long pipe: inhibition of sulphide production by nitrite from the secondary treatment.

The agricultural reuse of reclaimed wastewater has become a necessity in places with water shortages. Frequently, this involves the operation of long transportation pipelines, like in the South Tenerife reuse system, whose main element is a completely filled 61 km long gravity pipe in cast iron. Sulphide generation, which could contribute to pipe corrosion, is a usual process taking place during transportation if anaerobic conditions prevail. In the Wastewater Treatment Plant of Santa Cruz (Tenerife, Spain) a partial nitrification process was achieved by increasing the mean residence time through the aeration step at low dissolved oxygen concentration. Such conditions, combined with the right temperature and a free ammonia concentration above 1 mg l(-1), inhibited nitratation and favoured nitritation, which led to concentrations of NO2-N above 8 mg l(-1) in the secondary effluent. During the transportation, nitrite inhibited the appearance of anaerobic conditions, and, consequently, no sulphide generation occurred. At the same time, a nitrite reduction process took place with a first order kinetics and a rate coefficient of 0.052 h(-1)' at 25 degrees C. A parallel behaviour between the nitrite depletion and the oxidation-reduction potential evolution along the pipeline was also observed.

Ammonia↗
PubMed2004

[Encephalitis in a renal transplantation patient].

The patient was a 55 year-old-woman with chronic renal failure due to idiopathic mesngial deposition of Ig A. She received a second allograft of a kidney from a cadaver. Results of a preoperative serologic Ig G tests for EBV and CMV were positive. She was given triple-drug immunosuppressive therapy, consisting of cyclosporine,azathioprine, and steroids. Seven years later, azathioprine was changed to mycophenolate mofetil. One year later, she was admitted to the hospital with a three to four week history of vertigo (which did not improve after sulpiride was administrated) and an influenza-like syndrome. A CT scan of the brain appeared normal, so paroxysmal positional vertigo was the diagnosis. Two weeks after admission to the hospital, the patient reported visual hallucinations and impairment of consciousness. Results of laboratory tests were leukocyte increase (polymorphonuclear leukocytes), anemia, hyponatremia and renal failure. Chest radiography, brain CT, and electroencephalography revealed no pathologic signs. The CSF examination revealed 300 cells/ml (79% PMNL), glucose 63 mg/dl, protein 45 mg/dl. Six hours later the treatment was initiated with ampicillin, ceftriaxone and ganciclovir iv, she experienced seizures that affected the left side of her body, but without interictal recovery. The patient required intubation and mechanical ventilation in the intensive care unit. An MRI of the brain images, revealed high signal-intensity regions indicating lesions on the bulb, protuberance, mesencephalon, left thalamus and parenchyma adjacent to the corpus callosum (fig. 1). Six days later, the patient partially recovered consciousness, and she had not neurologic sequelae. Intubation was terminated. As soon as PCR revealed EBV DNA in CSF samples, the treatment with ceftriaxone and ampicillin was discontinued. Treatment with ganciclovir was maintained for 8 weeks (4 weeks with iv and another 4 weeks with oral treatment). On day 35, the examination of a specimen of CSF revealed: glucose 46, protein 78, 15 cells/ml (100% lymphocytes). The patient went home on day 55 after admission to our hospital. She regained her normal neurologic function. Three weeks later MRI, showed reduction of the size of the lesions and the lesions on the brain stem had disappeared.

Adrenal Cortex Hormones↗
PubMed2002

[Evaluation of the efficacy and efficiency of a multidisciplinary unit for the treatment of patients with colorectal cancer].

INTRODUCTION: Because of the increased complexity of the diagnostic-therapeutic approach to colorectal cancer (CRC), these patients should be managed in specialized multidisciplinary units. The aim of this study was to evaluate the efficacy and efficiency of a CRC unit (CRCU) in the diagnostic-therapeutic management of these patients. PATIENTS AND METHODS: Two groups of 50 patients with colon cancer treated in our center before and after the implementation of the CRCU were selected. Fulfillment with the protocol in terms of tumoral staging, surgical and adjuvant treatment, follow-up, interval until treatment, hospital stay, morbidity and early mortality, and the overall duration of the diagnostic-therapeutic process was analyzed. In addition, clinical workload was evaluated and a cost-minimization analysis was performed. RESULTS: The CRCU reduced the interval until surgery (20.3 12.0 vs 28.0 20.4 days; p = 0.05), hospital stay (9.8 7.7 vs 14.5 9.3 days: p = 0.01), the time to the start of adjuvant treatment (29.4 10.2 vs 39.7 19.8 days; p = 0.03) and the overall duration of the process (60.4 23,8 vs 82.1 46.1 days; p = 0.05), representing a saving of 978.85 E per patient. This improvement took place despite an increase in clinical workload (24% in 5 years in relation to the number of admissions) and had no effect on morbidity (26 vs 24%; NS) or immediate mortality (6 vs 4%; NS). CONCLUSION: Specialized multidisciplinary units increase the efficacy and efficiency of the management of patients with CRC.

Aged↗
PubMed2001

The management of leaking rectal anastomoses by minimally invasive techniques.

BACKGROUND: The salvage of a leaking rectal anastomosis has been reported in selected cases. Herein we present our experience in the management of rectal anastomotic dehiscence by minimally invasive techniques. METHODS: A total of 94 patients underwent anterior rectal resection for rectal cancer in an 18-month period. The operation was laparoscopic-assisted in 76 cases (81%). RESULTS: Clinical anastomotic dehiscences occurred in 10 cases (10.6%). Conservative therapy, including the percutaneous drainage of pelvic abscesses, was successful in three cases. Among the seven patients who required reoperation, the anastomosis was taken down in only one case. In four of these cases, the reoperation was performed laparoscopically, including peritoneal lavage and the creation of a diverting stoma. There were no complications resulting from the use of laparoscopy in the early postoperative period. Closure of the stoma was possible in eight patients. CONCLUSIONS: The salvage of a leaking rectal anastomosis is feasible in the vast majority of these cases (80%). The combination of laparoscopy and interventional radiology is a good alternative to laparotomy in patients who have had previous laparoscopic rectal excision.

Abscess↗
PubMed2001

Acute phase response in laparoscopic and open colectomy in colon cancer: randomized study.

PURPOSE: All types of trauma to the organism produce a systemic response that is proportional to the severity of the lesion caused. The more rapid clinical recovery during the postoperative period of patients undergoing laparoscopic-assisted colectomy vs. patients receiving conventional surgery suggests that laparoscopic surgery produces less surgical trauma. The aim of this randomized, prospective study was to compare acute phase postoperative response in patients diagnosed with colon neoplasm undergoing open segmentary colectomy vs. laparoscopic-assisted colectomy. METHODS: From June 1994 to July 1997 the results of 97 patients (58 submitted to open colectomy and 39 undergoing laparoscopic-assisted colectomy) were analyzed. Blood determinations of cortisol, prolactin, C-reactive protein and interleukin-6 were performed before surgery and at 4, 12, 24, and 72 hours after surgery. RESULTS: The plasma levels of cortisol and prolactin were higher in the postoperative period with both surgical techniques with no significant differences being observed. The levels of interleukin-6 achieved a maximum peak at 4 hours after surgery, later showing a decrease and practically achieving basal levels at 72 hours in both groups. The levels of interleukin-6 were higher with significant differences at 4, 12, and 24 hours in the patients undergoing open colectomy. The plasma levels of C-reactive protein were significantly lower at 72 hours in patients receiving laparoscopic-assisted colectomy. CONCLUSIONS: The results obtained in this randomized, prospective study suggest that acute phase systemic response is attenuated in patients undergoing laparoscopic-assisted colectomy in comparison with patients receiving open colectomy.

Acute-Phase Reaction↗
PubMed2001

Screening a large reference sample to identify very low frequency sequence variants: comparisons between two genes.

Most human sequence variation is in the form of single-nucleotide polymorphisms (SNPs). It has been proposed that coding-region SNPs (cSNPs) be used for direct association studies to determine the genetic basis of complex traits. The success of such studies depends on the frequency of disease-associated alleles, and their distribution in different ethnic populations. If disease-associated alleles are frequent in most populations, then direct genotyping of candidate variants could show robust associations in manageable study samples. This approach is less feasible if the genetic risk from a given candidate gene is due to many infrequent alleles. Previous studies of several genes demonstrated that most variants are relatively infrequent (<0.05). These surveys genotyped small samples (n<75) and thus had limited ability to identify rare alleles. Here we evaluate the prevalence and distribution of such rare alleles by genotyping an ethnically diverse reference sample that is more than six times larger than those used in previous studies (n=450). We screened for variants in the complete coding sequence and intron-exon junctions of two candidate genes for neuropsychiatric phenotypes: SLC6A4, encoding the serotonin transporter; and SLC18A2, encoding the vesicular monoamine transporter. Both genes have unique roles in neuronal transmission, and variants in either gene might be associated with neurobehavioral phenotypes.

Alleles↗
PubMed2001

Molecular evidence for precambrian origin of amelogenin, the major protein of vertebrate enamel.

Although molecular dating of cladogenetic events is possible, no molecular method has been described to date the acquisition of various tissues. Taking into account the specificity of the major protein in enamel in formation (amelogenin), we were able to develop such a method for enamel. Indeed, because the amelogenin protein is exclusively involved in enamel formation and mineralization and because it lacks pleiotropic effects, this protein is a good candidate to estimate the date of acquisition of this highly mineralized tissue. We searched DNA banks for similarities between the amelogenin sequence and other sequences. Similarities were found only to exon 2 of SPARC (osteonectin) in two protostomians and in eight deuterostomians, and to exon 2 of three SPARC-related deuterostomian genes (SC1, hevin, and QR1). The other amelogenin exons did not reveal significant similarities to other sequences. In these proteins, exon 2 mainly encodes the peptide signal that plays the essential role in enabling the protein to be ultimately localized in the extracellular matrix. We tested the significance of the exon 2 similarities. The observed values were always significantly higher than the expected randomly generated similarities. This demonstrates a common evolutionary origin of this exon. The phylogenetic analyses of exon 2 sequences indicated that exon 2 was duplicated to amelogenin from an ancestral SPARC sequence in the deuterostomian lineage before the duplication of deuterostomian SPARC and SC1/hevin/QR1. We were able to date the origin of the latter duplication at approximately 630 MYA. Therefore, amelogenin exon 2 was acquired before this date, in the Proterozoic, long before the so-called "Cambrian explosion," the sudden appearance of several bilateralian phyla in the fossil record at the Proterozoic-Phanerozoic transition. This sudden appearance has been often suggested to reflect intensive cladogenesis during this period. However, molecular dating of protostomian-deuterostomian divergence and of the cladogenesis among several major clades of Bilateralia lead to a different conclusion: many bilateralian clades were already present during the late Proterozoic. It has previously been proposed that these bilateralians were not mineralized and that they had low fossilization potential. Our results strongly suggest that late Proterozoic fossils possessing a mineralized tissue homologous to enamel might be found in the future.

Amelogenin↗
PubMed2001

Ammonia removal in a deep reclaimed wastewater reservoir before agricultural reuse.

An experimental study has been carried out to determine the ammonia removal in a deep reclaimed wastewater reservoir of 50,000 m3. The reservoir is part of the Reuse System of Reclaimed Wastewater of South Tenerife (Spain). The study has been conducted under batch mode operation, in three different periods (winter, spring-summer and winter-spring), with an average storage time of 85 days. Vertical profiles of temperature, dissolved oxygen and pH were determined together with NH3-N, NO2-N and NO3-N concentrations at different points and different depths in the reservoir. Maximum removal efficiency was obtained during the winter periods, in absence of stratification and with good mixing conditions throughout the water column. During these periods, nitrification took place in some extension, favoring the ammonia removal. Average NH3-N concentrations in the reservoir were calculated and apparent first-order rate constants were determined for different stratification conditions. Although ammonia nitrogen could be used as nutrient in the agricultural reuse, its removal from reclaimed wastewater could be useful in order to diminish the chlorine needs for disinfection.

Agriculture↗
PubMed2001

How partial nitrification could improve reclaimed wastewater transport in long pipes.

Reclaimed wastewater transport is studied in a concrete-lined cast iron pipe, where a nitrification-denitrification process occurs. The pipe is part of the Reuse System of Reclaimed Wastewater of South Tenerife (Spain), 0.6 m in diameter and 61 km long. In order to improve wastewater quality, at 10 km from the inlet there is injection of fresh water saturated in dissolved oxygen (DO), after which a fast nitrification process usually appears (less than two hours of space time). The amount of oxidized nitrogen compounds produced varies between 0.8 and 4.4 mg/l NOx(-)-N. When DO has disappeared, a denitrification process begins. The removal of nitrite is complete at the end of the pipe, whereas the nitrate does not disappear completely, leaving a concentration of about 0.4-0.5 mg/l. For a COD/NOx(-)-N ratio higher than 5, a first order nitrification rate in NOx(-)-N has resulted, with the constant k20 = 0.079 h-1, for a NOx(-)-N concentration range of 0.8-4.4 mg/l. Finally the following temperature dependency for the first order denitrification rate constant has been found: k = k20 x 1 x 15T-20. Although nitrogen could be used as nutrient in the agricultural reuse, its removal from reclaimed wastewater could be useful in order to diminish the chlorine needs for reclaimed wastewater disinfection.

Agriculture↗
PubMed2000

Could age be an indication for laparoscopic colectomy in colorectal cancer?

BACKGROUND: The incidence of colorectal carcinoma increases in the elderly. Regardless of age as an isolated factor, postoperative complications represent the main factor in increasing hospital mortality. METHODS: The aim of this study was to compare the short-term results (first 30 postoperative days) after laparoscopically assisted colectomy (LAC) and open segmental colectomy (OC) in colorectal carcinoma between two groups of patients, older than 70 and younger than 70 years of age. In the study from November 1993 to June 1998, 255 patients were evaluated to participate. RESULTS: Peristalsis, oral intake, and discharge from the hospital occurred earlier in LAC than in OC treated patients, in the two age groups. The mean operative time was significantly longer in the LAC than in the OC patients in the two age groups. No differences were observed in morbidity between LAC and OC in the group younger than 70 years of age. However, the overall morbidity was significantly lower in the LAC group in patients older than 70 years. One patient in the LAC group older than 70 years died. CONCLUSION: These results suggest that laparoscopically assisted colectomy may be particularly indicated in elderly patients.

Age Factors↗
PubMed1999

Inguinal lymph node metastases from rectal adenocarcinoma.

BACKGROUND AND OBJECTIVES: The prognosis of patients with inguinal lymph node metastases from rectal adenocarcinoma is poor. The purpose of this study is to analyze the clinical behavior and response to different therapies in a group of these patients. MATERIALS AND METHODS: The medical records of 32 patients with inguinal lymph node metastases from rectal adenocarcinoma, diagnosed between January 1985 and December 1996, were retrospectively analyzed. The cohort was divided into: Group A (synchronous), and Group B (metachronous), according to the time of diagnosis. RESULTS: There were 17 males and 15 females, with a mean age of 53.5+/-13.8 years. Bilateral inguinal lymph node metastases were diagnosed in 17 patients, and unilateral in 15 patients. Fourteen of 18 patients in Group A (78%) and 13 of 14 patients (93%) in group B, respectively, had concomitantly extrapelvic metastatic disease. Seventeen patients in Group A treated with colostomy + chemoradiotherapy (45 Gy/20 fractions to the pelvis and groin area + 5-fluorouracil 450 mg/m2/weekly) had a progressive metastatic disease; the remaining patient was lost to follow-up after an abdominoperineal resection plus superficial groin dissection. Median survival was 8 months (range, 4-30 months). Overall 5-year survival was 0%. Ten patients in Group B were treated with chemoradiotherapy (50 Gy/25 fractions + 5-fluorouracil 450 mg/m2 + leucovorin 30 mg/m2); three patients received supportive care only, and one patient was treated with a groin dissection. All of them died of disseminated metastatic disease at a median of 13 months (range, 6-57 months). Overall 5-year survival was 0%. CONCLUSION: The presence of inguinal metastases in patients with rectal cancer heralds systemic disease and, due to a poor response to the different therapies, only palliative treatment should be indicated.

Adenocarcinoma↗
PubMed1999

Prognostic factors in patients with locally advanced rectal adenocarcinoma treated with preoperative radiotherapy and surgery.

Preoperative radiation therapy (PRT) prior to potential curative resection for rectal adenocarcinoma is not widely accepted. This report evaluates the prognostic factors affecting local recurrence and 5-year survival. This is a retrospective study of 214 patients with primary rectal adenocarcinoma treated from January 1986 to December 1994. A PRT dosage of 45 Gy in 20 fractions was administered to patients with clinically tethered or fixed tumors, and 4 to 8 weeks later surgery was performed (group I). Patients with clinically mobile tumors were treated by surgery alone (group II). There were 130 men and 84 women. The median age was 58 years (range 19-85 years). There were 111 patients in group I: 7 patients had no microscopic residual tumor, 80 had Dukes' A and B, and 24 had Dukes' C. There were 103 patients in group II: 70 patients were classified as Dukes' A and B and 33 as Dukes' C. The mean follow-up of the entire cohort was 62 months (range 2-132 months). Local recurrence was seen in 17% of patients in group I and 35% in group II (p = 0.002). Distant recurrence in patients with metastatic lymph nodes was seen in 79% of group I and in 34% of group II (p = 0.001). The favorable prognostic factors for local control were the administration of PRT and well differentiated cancer. The favorable prognostic factors for survival were age < 50 years and the absence of lymph node metastasis. The administration of PRT diminishes the risk of local recurrence. The presence of metastatic lymph nodes in the postirradiated specimen is an ominous prognostic factor for survival. Therefore such patients should be considered for adjuvant chemotherapy.

Adenocarcinoma↗