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C Cordero

Publications and source records attributed to C Cordero.

18 recordsLinked to original sources
PubMed2005

High-speed gas chromatography with direct resistively-heated column (ultra fast module-GC)-separation measure (S) and other chromatographic parameters under different analysis conditions for samples of different complexities and volatilities.

The influence of GC speed on the separation capability of a chromatographic system is reported measuring a series of parameters including separation measure (S), peak capacity (n), peak width (w), analysis time, t(b) (determined on the last eluting compound) and separation measure/analysis time ratio (S/t(b)) determined by analyzing a bergamot essential oil sample and a standard mixture of pesticides. Conventional GC, fast GC (with 10 m (FGC10) and 5 m (FGC5) narrow-bore columns), and direct resistively-heated ultra fast module-GC (UFM-GC) were the GC speed approaches used. The influence of different heating rates with a constant flow for FGC5, FGC 10, and UFM-GC and with variable flows for UFM-GC on S, n, w, S/t(b), and t(b) was also studied. The results of this study show that: (a) separation capability of the chromatographic system (i.e. S and n) and analysis time depend on the GC approaches. Within each GC approach, S and n and analysis time depend on the heating rates, although to a different extent, and S and n decrease much less than the gain in analysis time, in particular when fast heating rates are applied; (b) in UFM-GC, the loss of separation capability with heating rate can also be partially compensated by the choice of an appropriate flow rate that, within each heating rate, may contribute to increase S while reducing t(b); (c) within a specific GC approach, the chromatographic system (column and stationary phase) and conditions (heating and flow rates) must be such to achieve a suitable S-value when two analytes must be separated with a given resolution in a minimum analysis time.

Chromatography, Gas↗
PubMed2003

Female choice of sexually antagonistic male adaptations: a critical review of some current research.

We contrast some recent uses of the concept of male-female conflict, with the type of conflict that is inherent in traditional Darwinian female choice. Females in apparent conflict situations with males may suffer reduced lifetime reproduction, but nevertheless benefit because they obtain sons with superior manipulative abilities. Female defences against male manipulations may not be 'imperfect' because of inability to keep pace with male evolution, but in order to screen males and favour those that are especially good manipulators. We examine the consequences of these ideas, and of the difficulties of obtaining biologically realistic measures of female costs, for some recent theoretical and empirical presentations of male-female conflict ideas, and find that male-female conflict in the new sense is less certain than has been commonly supposed. Disentangling previous sexual selection ideas and the new conflict of interest models will probably often be difficult, because the two types of payoffs are not mutually exclusive.

Adaptation, Biological↗
PubMed2001

Determination of daminozide residues in apple pulp using HPLC-DAD-UV.

This paper reports an HPLC-UV method to determine daminozide residues in apple pulps adopting the recently introduced EU limit of 0.01 mg/kg for baby food preparation (Commission Directive 1999/39/CE). The method is based on alkaline hydrolysis of daminozide to N',N'-dimethylhydrazine (UDMH), which is recovered by distillation and subsequently derivatizated with salicyl aldehyde to salicyl aldehyde-N,N-dimethylhydrazone under strongly basic conditions. The resulting solution was cleaned up with Extrelut 20 NT and dichloromethane as eluent, then analyzed by HPLC with a C18 column and a mobile phase programmed from 50:50 AcCN/H(2)O to 100% AcCN. The salicyl aldehyde-N,N-dimethylhydrazone was selectively detected through two diagnostic UV absorption maxima at 295 and 325 nm, which have strong molar absorbivities. Recoveries of daminozide at 0.01 mg/kg were above 80%. The limits of detection (LODs) of salicyl aldehyde-N,N-dimethylhydrazone expressed as daminozide concentration were 100 pg/microL at 295 nm and 150 pg/microL at 325 nm, and the limits of quantitation (LOQs) of daminozide were 0.0013 mg/kg at 295 nm and 0.0022 mg/kg at 325 nm.

Gas Chromatography-Mass Spectrometry↗
PubMed2001

Validity of early colonoscopy for the treatment of adenomas missed by initial endoscopic examination.

OBJECTIVE: To determine whether the features of adenomas identified in a first endoscopic examination may predict the presence of polyps with advanced pathological features that may have gone unnoticed and whether early colonoscopy may benefit these patients. MATERIAL AND METHODS: We examined 133 patients with diagnosis of colonic adenomas who had undergone complete colonoscopy and endoscopic polypectomy. All of them underwent colonoscopic follow-up at 3 years. Seventy nine patients underwent colonoscopic follow-up both at 6 months and at 3 years, while 54 patients underwent just colonoscopic follow-up at 3 years and 47 just at 6 months. RESULTS: Fifteen per cent of the patients analyzed developed polyps with pathological features after 6 months. The size and histological analysis of the polyps detected in the initial colonoscopic examination did not affect these results (p < 0.05). The number of polyps was statistically significant: patients with 3 or more polyps in the initial colonoscopic examination presented more polyps with pathological features after six months (25.8 versus 5.8%, p = 0002). This follow-up examination at 3 years did not reveal a higher occurrence of polyps with pathological features in any of the two groups of patients, namely, those who had undergone early colonoscopy and those who had not. CONCLUSIONS: Patients with multiple polyps have greater probability of developing synchronous polyps with some pathological features which may have gone unnoticed. Since early examination has not shown to provide a benefit for these patients, the first follow-up colonoscopy should be performed at 3 years, particularly if the initial colonoscopy is negative.

Adenoma↗
PubMed1992

[Segmental small intestine transplantation in dogs: comparison between a jejunal graft and an ileal graft].

The aim of this study was to compare segmental grafts of jejunum and ileum in a dog model. 14 segmental grafts, 8 ileal (Il. A) and 6 jejunal (Jej. A.), were successfully allografted as 120 cm-Thiry-Vella segments. Immunosuppressive therapy consisted of cyclosporin 25 mg/kg/day per os. Monitoring was performed by histology and absorption (maltose and xylose) studies as well as analysis of brush border enzymes. No cases of Graft-versus-host disease were observed. Six allografts (42.5 per cent) including 3 Jej. A. (50 per cent) and 3 Il. A. (37.5 per cent) were rejected during the first three months. Eight allografts (5 Il. A. and 3 Jej. A.) were tolerated for up to 3 months and were removed: 2 Il. A. and 2 Jej. A. were normal, while 2 Il. A. and one Jej. A presented with signs of chronic rejection and one Il. A. with advanced rejection. Jej. A. and Il. A. showed a similar course, by means of immunologic reactions as well as functional characteristics. It is concluded that there is no major difference between Jej. A. and Il. A. in the dog. Because of the specialized absorptive functions of the ileum and its adaptative properties, ileal segmental grafts should be preferred to jejunal grafts for the treatment of short-gut syndrome.

Alkaline Phosphatase↗
PubMed1990

[Role of coloproctectomy with colonic-anal anastomosis in the treatment of rectal cancer].

The aim of this study was to determine the efficacy and long term results of straight colo-anal anastomosis (CAA) after resection for rectal carcinoma as described by Parks. From January 1986 to June 1989, 40 patients underwent this operation: 27 men and 13 women with a mean age of 63.5 years (range 37-81). In 36 cases, the indication was for carcinoma of mid and low rectum and in 4 cases for carcinoma of the upper rectum associated with a low rectal benign tumour (3 Dukes A, 19 Dukes B, 13 Dukes C, and 5 Dukes D). A diverting colostomy was constructed in all cases. Operative mortality was one patient (2.5 per cent) by pulmonary embolism. Anastomotic dehiscence occurred in four patients. None of these patients required reoperation and all colostomies have been closed. 6 patients presented a local recurrence (15.4 per cent) 6 to 34 months after CAA, of whom two were treated by abdomino-perineal resection. 5 patients died 6 to 34 months after CAA from local recurrence (2 cases) or distant metastasis (3 cases) and one patient has liver disease. All others patients are alive free of disease with a mean follow-up of 21.7 months (range 3-46 months). Actuarial survival is 77 per cent at 40 months. Functional results were assessed in the 26 patients followed up more than one year. The mean stool frequency was 2.4 per day (range 0, 3-6). All patients are continent, with a good discrimination gas-stool. 4 patients (15.4 per cent) suffer from soiling, 5 (19 per cent) from stool frequency, and 2 (7.7 per cent) from urgency. In conclusion, CAA is a good alternative of abdominoperineal resection for some mid and low rectal carcinomas. Functional results might be improved by the construction of a colonic reservoir.

Adenocarcinoma↗
PubMed1988

Apathy into support.

Explore the source record for details and available documents.

Allied Health Personnel↗
PubMed1987

Clinical evaluation of pediculicidal and ovicidal efficacy of two pyrethrin-piperonyl-butoxide formulations.

The pediculicidal and ovicidal efficacy of two pyrethrin-piperonyl-butoxide agents was evaluated in 40 children infested with head lice. Both commercial products, a lotion and a shampoo, had similar formulations. Specifically, the shampoo vehicle was tested to determine whether its surface-tension-lowering action made it more effective as an ovicidal agent than the lotion. Results of the study indicate that the shampoo is 49% more effective than the lotion as an ovicide.

Administration, Topical↗
PubMed1986

[Short-term antibiotic prophylaxis in colorectal surgery: cefoxitin versus piperacillin. A double-blind randomized study, 60 cases].

A randomized, double-blind comparative trial of cefoxitine and piperacillin was conducted in two groups of 30 patients with a similar number of the usual risk factors. Doses of cefoxitine 2 g and piperacillin 4 g were administered only once, except in some cases when the operation lasted more than 5 hours. Analysis of the results showed that the two antibiotics had equivalent prophylactic effectiveness (congruent to 6%) in colorectal surgery.

Abscess↗
PubMed1986

Multicentre double-blind clinical trials of ciclopirox olamine cream 1% in the treatment of tinea corporis and tinea cruris.

In separate multicentre, randomized, double-blind clinical trials, 1% ciclopirox olamine cream was compared with its cream vehicle and with 1% clotrimazole cream as treatment for tinea corporis and tinea cruris. Patients who demonstrated clinical and mycological findings consistent with the diagnoses of tinea corporis or tinea cruris were included in the study. Clinical and mycological evaluations were made pretreatment, at the end of each of the four weeks of treatment, and weekly for the two weeks immediately following cessation of treatment. In both studies, use of ciclopirox olamine cream resulted in demonstrable improvements after the first week of therapy and in complete clinical and mycological clearing in two thirds of the patients at the end of the treatment period. These results were maintained through the two-week drug-free observation period that followed the end of treatment. Statistically, the results with ciclopirox olamine cream were significantly better than those with the vehicle and were equivalent to those with clotrimazole cream. All treatments were well tolerated.

Administration, Topical↗
PubMed1979

[Seroepidemiological study of Herpes simplex virus type 2 in adult women of Costa Rica].

The frequency of genital Herpes simplex type 2 infections in a group of twenty adult Costa Rican women was studied by isolation of the virus and the measurement of neutralizing antibody activity in sera. The virus could not be isolated in any of the vaginal secretions. Neutralizing antibody activity to herpes virus types 1 and 2 was found in sera from sixteen subjects. An antibody II/I index equal to or larger than 87, indicative of infection with Herpes simplex type 2 was found in fifty per cent of the population studied, a second segment was composed by the subjects with indices below 87. Evaluation of antibody activity to Herpes simplex type 2 revealed that: a) only a small percentage of the women lacked detectable antibody activity to the virus; b) there is a significant difference (p < 0.005) between the mean number of years of sexual experience among the two population segments; and c) there is a positive correlation (p < 0.05) between II/I index values and age among the women of the population segment with a II/I index equal to or larger than 87.

Adolescent↗
PubMedDate not supplied

HPLC-UV and HPLC-positive-ESI-MS analysis of the diterpenoid fraction from caper spurge (Euphorbia lathyris) seed oil.

Caper spurge (Euphorbia lathyris L.) seed oil contains a series of diterpenoids known as Euphorbia factors, or L-factors, L1-L9. They are esters of several polyols (lathyrol, epoxylathyrol, hydroxylathyrol and ingenol) and account for about 3-5% of the oil. The percentage of ingenol-based L-factors is very low, less than 5% of the diterpenoid fraction, but some of them (factors L5 and L6) are responsible for the irritant and co-carcinogenic activities of the oil. This paper reports an HPLC-UV and HPLC-positive-ESI-MS analysis of the diterpenoid fraction of caper spurge seed oil before and after selective hydrolysis of ingenol-based L-factors. Separation of lathyrane polyols and esters, and ingenol and its esters was achieved using a chromatographic system consisting of a C18 stationary phase and acetonitrile: water as mobile phase. A new macrocyclic constituent, the deoxy Euphorbia factor L1, was identified in the oil.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

The treatment of dermatophytoses of the glabrous skin: a comparison of undecylenic acid and its salt versus tolnaftate.

In a double-blind study, the efficacy of 1% tolnaftate cream, 3% undecylenic acid and its zinc salt, and a placebo cream were tested in dermatophytosis of the glaborous skin and groin. Ninety-seven subjects completed the study: 33 received tolnaftate, 23 of these subjects were cured clinically and mycologically. Thirty-two subjects received 3% undecylenic acid and 20% zinc undecylenate as a cream. Of these, 21 were cured clinically and mycologically. Only three of the 32 subjects receiving placebo were cured clinically and mycologically. Both tolnaftate and undecylenic acid and its zinc salt are effective in this condition.

Clinical Trials as Topic↗
PubMedDate not supplied

A dosing study of nonoxynol-9 and genital irritation.

The objective of the study was to assess the symptoms and signs of genital irritation produced by different frequencies of nonoxynol-9 (N-9) use. Thirty-five women were randomized to each of 5 groups and used a vaginal suppository for 2 weeks. Group 1: N-9 once every other day; Group 2: N-9 once a day; Group 3: N-9 twice a day; Group 4: N-9 4 times a day; and Group 5: placebo 4 times a day. Study women were examined at admission, one week and 2 weeks with a colposcope for erythema and epithelial disruption, and were interviewed about vaginal itching and burning. The rates of reported symptoms for N-9 users were not significantly different from that of placebo users. The rate of epithelial disruption for women using N-9 every other day was essentially the same as that of women using placebo. The rates of epithelial disruption for women using N-9 1/day and 2/day were 2.5 times greater than that of placebo users. The rate of epithelial disruption for women using N-9 4/day was five times greater than that of placebo users. Genital irritation was located primarily on the vagina or cervix, and vulvitis was not a significant problem. Women who infrequently use N-9 products may not experience an increase in genital irritation. Women who choose to use N-9 frequently may experience an increase in epithelial disruption.

Adolescent↗
PubMedDate not supplied

Simultaneous determination of six triazolic pesticide residues in apple and pear pulps by liquid chromatography with ultraviolet diode array detection.

A method is described for the simultaneous determination of diclobutrazol, flusilazole, flutriafol, hexaconazole, paclobutrazol, and tetraconazole in apple and pear pulps used in baby food at a limit of 0.01 mg/kg. Apple and pear pulp samples are subjected to selective solid-phase microdispersion (SPMD) with SPE-ED Matrix-38 and acetone-cyclohexane, and the extracts are cleaned up on a Florisil cartridge with hexane-cyclohexane-acetone. The extracts are then analyzed by liquid chromatography with ultraviolet detection, using an octadecylsilane column with a gradient-programmed acetonitrile-water mobile phase. Recoveries were determined by spiking apple and pear pulps with the 6 pesticides under investigation at 0.1, 0.05, 0.03, and 0.01 mg/kg. Six determinations were performed at each level for each pesticide. Recoveries were > or = 70% at the 0.01 mg/kg level.

Calibration↗