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D Castro

Publications and source records attributed to D Castro.

At least 37 records · Page 2Linked to original sources
PubMed1998

Intratumoral cisplatin/epinephrine-injectable gel as a palliative treatment for accessible solid tumors: a multicenter pilot study.

Intratumoral injections of cisplatin/epinephrine-injectable gel were administered weekly for 4 weeks in 45 patients with malignant tumors of various histologic types. Tumors were located on the skin and subcutaneous tissue primarily of the head, neck, and trunk, and on the tongue, oral pharynx, and esophagus. Patients were not candidates for surgery, radiation, or systemic chemotherapy. Each of the treated tumors (n = 82) was evaluated 2, 4, 8, and 12 weeks after the final injection. The initial dose of cisplatin was 1 mg/cm3 tumor volume, with escalation to 6 mg/cm3 allowed, depending on observed toxicities. The mean cumulative dose per patient for the four treatments ranged from 0.56 to 380 mg cisplatin. No dose-limiting cisplatin-related toxicities, such as nephrotoxicity, neurotoxicity, or ototoxicity, were observed. The overall objective tumor response rate was 50% (41 of 82), with 40% (33 of 82) complete responses and a median response duration of 160 days. Complete responses for adenocarcinoma and squamous cell carcinoma were 58% (21 of 36) and 38% (12 of 32), respectively. These results justified further clinical trials to evaluate the role of local chemotherapy with intratumoral cisplatin/epinephrine-injectable gel in the palliative treatment of patients with selected accessible solid tumors.

Adenocarcinoma↗
PubMed1998

[Coronary arteriography with a very low profile catheter: efficacy and safety of the procedure and of the 60 minute hospital discharge].

PURPOSE: To evaluate the feasibility, efficacy and safety of the use of 4F Judkins catheters for coronary angiography. METHODS: From August/95 to January/96, 70 patients with suspected coronary artery disease underwent coronary cineangiography by the Judkins technique, with 4F catheters. Following puncture of the right femoral artery, 4F sheaths were introduced. At the end of the procedure, the sheath was removed and manual compression was applied for 15 min. Patients were oriented to walk under specialized supervision, 60 min after the procedure, and discharged after 4h. RESULTS: Thirty nine (56%) patients were male, the age ranged from 31 to 83 (mean 57) years and weight from 43 to 101 (mean 69) kg. Optimal quality images were obtained in 62 patients (88%). It was necessary to use larger caliber catheters (6 and 8F) in 8 patients, due to femoral tortuosity or inadequate opacification of coronary arteries. There were no vascular complications nor major bleedings. In only 2 cases (3%) there was a minor bleeding, treated by new local compression. Sixty (85%) patients walked after 60 +/- 5 min and were discharged after 4h. CONCLUSION: The use of 4F catheters for coronary angiography by femoral approach allowed early deambulation with no major bleeding. Image quality was good, with little contrast used and short hospital stay. This technique may lead to a simpler less traumatic and less invasive coronary angiography.

Adult↗
PubMed1998

Appraisal and implications of predictive testing for insulin-dependent diabetes mellitus.

The risk of developing insulin-dependent diabetes mellitus (IDDM) is 50 times greater in first-degree relatives than in the general population. Although parents of a diabetic child are generally aware of the risk of disease recurrence in the family, the practice of screening for IDDM is often questioned by physicians themselves because of the likelihood that parents will experience anxiety. This paper reports the results of a questionnaire distributed to parents attending a pediatric clinic for their diabetic child who were asked to evaluate their attitudes about screening tests. One hundred and thirty-one families recruited over a 2-month period replied to the questionnaire without the assistance of medical staff. The mean age of diabetic children was 10 +/- 4.05 years, and the duration of IDDM 3 +/- 3.6 years. The results show that parents were stressed by the possible development of a second case of IDDM among their children. Eighty percent of them practised home strip--analysis on a regular basis for all their children. The parents wanted biological tests to be performed on their children before the occurrence of any clinical symptoms. They expected the screening tests "to reveal the truth about the health status of their children" (92%) and to "help prepare for an uncertain future" (60%). They indicated that recognition of an increased risk would not change their attitude toward their child. Recurrence of the disease was regarded as a problem with which the parents could cope realistically. Our data indicate that parents should continue to be informed about familial risk and the possibility of screening, despite the lack of preventive treatment.

Child↗
PubMed1997

Analysis of the mechanism of quinolone resistance in nalidixic acid-resistant clinical isolates of Salmonella serotype Typhimurium.

Over a period of 2.5 years, 42 cases of gastro-enteritis caused by nalidixic acid-resistant Salmonella serotype Typhimurium occurred in Malaga. The epidemiological relationship among the strains involved was investigated by analysis of plasmid profile and of chromosomal DNA by pulsed-field gel electrophoresis (PFGE). Despite having different plasmid profiles, all 42 nalidixic-acid resistant Typhimurium isolates had evolved from one clone as shown by analysis of chromosomal DNA by PFGE. The mechanism of quinolone resistance in these Typhimurium isolates was also investigated. Analysis of outer-membrane proteins and lipopolysaccharide from quinolone-susceptible and resistant clinical isolates tested showed no differences. All nalidixic acid-resistant isolates had MICs for ciprofloxacin of 0.25 mg/L and for nalidixic acid of 1024 mg/L. Polymerase chain reaction fragments of 285 bp, containing the quinolone resistance-determining region of the gyrA gene, and of 237 bp, containing the region of parC homologous to the quinolone resistance-determining region of the gyrA gene, were sequenced. All resistant isolates presented a change at Ser-83 to Phe in the GyrA protein, but no changes were observed in the ParC protein. These findings indicated that this mutation in gyrA plays a major role in the acquisition of nalidixic-acid resistance in clinical isolates of Typhimurium.

Amino Acid Sequence↗
PubMed1997

Intraspecific characterization of Vibrio tapetis strains by use of pulsed-field gel electrophoresis, ribotyping, and plasmid profiling.

A total of twenty-two strains of Vibrio tapetis, the causative agent of brown ring disease affecting cultured clams, were compared and evaluated in an investigation of strain heterogeneity using pulsed-field gel electrophoresis (PFGE), ribotyping, and plasmid profile analysis. A total of 90.9% of V. tapetis strains tested by using NotI showed the same PFGE pattern, consisting of 15 bands. In contrast, the V. tapetis strains showed a low degree of similarity with six reference Vibrio species tested. All V. tapetis strains harbored a large plasmid of 74.5 kb. This plasmid was not detected in any of the other Vibrio species. In addition, endonuclease restriction analysis of the plasmid content of the strains using EcoRI and HindIII clearly showed that all the strains of V. tapetis possessed the same cleavage pattern. The three enzymes used for ribotyping, PvuII, SmaI, and SalI, yielded patterns with 8 to 12 bands ranging in size from 2 to 23 kb. The application of the SalI and SmaI endonuclease rendered the separation of the strains tested in two ribotypes, while all the V. tapetis strains belonged to the same ribotype when the enzyme PvuII was used.

Bacterial Typing Techniques↗
PubMed1996

Antioxidants, Helicobacter pylori and stomach cancer in Venezuela.

A randomized chemoprevention trial on precancerous lesions of the stomach is being conducted in Tachira State, Venezuela. The aims of the study are to evaluate the efficacy of vitamin supplementation in preventing the progression rate of precancerous lesions. Here we report on the pilot phase of the study in which two antioxidant preparations were evaluated on their ability to raise antioxidant levels in plasma and in gastric juice. The study aimed also to determine the antibiotic sensitivity profiles of Helicobacter pylori isolates prevalent in the area. Forty-three subjects with precancerous lesions (chronic gastritis, chronic atrophic gastritis, intestinal metaplasia and dysplasia) of the stomach were randomized to one of two antioxidant treatments. Treatment 1 (250 mg of standard vitamin C, 200 mg of vitamin E and 6 mg of beta-carotene three times a day) or treatment 2 (150 mg of standard vitamin C, 500 mg of slow release vitamin C, 75 mg of vitamin E and 15 mg of beta-carotene once a day) for 7 days. Blood levels of total vitamin C, beta-carotene and alpha-tocopherol and gastric juice levels of ascorbic acid and total vitamin C were measured before and after treatment on day 8. Both treatments increased the plasma levels of total vitamin C, beta-carotene and alpha-tocopherol/cholesterol but not those of ascorbic acid or total vitamin C in gastric juice. Treatment 1 was the best choice and resulted in a greater increase in the plasma levels of beta-carotene and alpha-tocopherol. H. pylori was cultured from 90% of the gastric biopsies; 35 isolates were identified which were highly resistant to metronidazole, a front-line antibiotic recommended against H. pylori in other settings.

Adult↗
PubMed1996

Interventional magnetic resonance imaging of the head and neck and new imaging techniques.

The use of magnetic resonance imaging to directly guide therapy is a new area of investigation. Clinical magnetic resonance imaging has the potential to evolve from a purely diagnostic tool into a guide for invasive procedures. The idea of using magnetic resonance to guide percutaneous biopsy developed one decade ago. Magnetic resonance-guided fine-needle aspiration for head and neck lesions has become a standard technique some institutions. Once the needle reaches a lesion in the head and neck, it is natural to explore the possibility of treatment in the same setting. The concept of interventional magnetic resonance imaging has generated interest among radiologists, surgeons, and manufacturers. This article provides an overview of interventional procedures of the head and neck and other new imaging techniques that have been developed.

Head and Neck Neoplasms↗
PubMed1996

Prevalence of precancerous lesions of the stomach in Venezuela.

Gastric biopsies from 1477 participants in a chemoprevention trial for precancerous lesions of the stomach in Venezuela were evaluated for the prevalence of precancerous lesions and Helicobacter pylori infection. These study subjects were selected from participants in an early detection program for gastric cancer using double-contrast X-ray. Overall, 94% had some type of chronic gastritis (CG) and were positive for H. pylori using Giemsa stain, 49% had atrophic gastritis, 34% had intestinal metaplasia (IM), and 6.5% had dysplasia. There were only three subjects (0.2%) with normal gastric mucosa, and 4% had only superficial gastritis. The prevalence of all of these precancerous lesions increased with age, but there was no clear difference by gender. The prevalence of the various lesions was higher in the antral mucosa than in the fundic mucosa. H. pylori infection was strikingly frequent in our study population, with prevalence rates ranging from 73% in subjects with superficial gastritis to 95% in those with atrophic gastritis and IM and 98% in those with CG. The prevalence of H. pylori was equally high in males and females, and it was significantly positively associated with the degree of infiltration of poly- and mononuclear cells and with that of active regeneration; it was inversely correlated with the degree of atrophy, IM, and dysplasia. Our findings support the precancerous nature of the various gastric lesions and the etiological role of H. pylori infection in CG.

Adult↗
PubMed1995

Determinants of plasma pepsinogen levels in a population at high risk for stomach cancer in Venezuela.

Determinants of plasma pepsinogens (PG) levels were studied in 1365 participants in a chemoprevention trial for gastric pre-cancerous lesions being conducted in Venezuela. Gastric biopsies, plasma samples and information on smoking and dietary habits were obtained at baseline examination. Both PG-I and PG-II levels increased progressively with the level of Helicobacter pylori infection in gastric biopsies, resulting in no clear trend in the I/II ratio. Instead, there was a progressive decrease in the I/II ratio with increasing degrees of infiltration of polynuclear cells and monocytes, atrophy, intestinal metaplasia and the stage of pre-cancerous lesions. The mean I/II ratios for atrophic gastritis or more advanced lesions were less than 4.0. When subjects with the I/II ratio 4 or higher were used as controls, severe reduction in the I/II ratio (< 2.0) was inversely associated with tobacco consumption. This may be due to a pharmacological effect of nicotine. The severe reduction of I/II ratio was also inversely associated with fresh fruit consumption. In addition, a decreased I/II ratio was positively associated with rice/pasta and arepas (tortilla made from corn) consumption and inversely associated with plantain consumption. Possible effects of vitamins and starchy food on the development of atrophic gastritis need to be studied further.

Adult↗
PubMed1995

A comparison of intraoperative ultrasound versus cholangiography in the evaluation of the common bile duct during laparoscopic cholecystectomy.

Indications for intraoperative evaluation of the common bile duct during laparoscopic cholecystectomy are controversial, as is the goal of either anatomic definition or assessing for choledocholithiasis. One hundred twenty-five consecutive patients undergoing laparoscopic cholecystectomy underwent both intraoperative ultrasound and intraoperative cholangiography. Cholangiography required slightly more time to perform; it was more sensitive (92.8% vs 71.4%) but less specific (76.2% vs 100%) for choledocholithiasis than was ultrasound. Ultrasound was somewhat more difficult to perform, and, particularly in the setting of intraabdominal obesity, was often inadequate at providing clear visualization of the intrapancreatic common bile duct. It did not provide the same anatomic definition as an adequate cholangiogram. The overall incidence of choledocholithiasis was 11.2%.

Cholangiography↗
PubMed1995

Interventional computed tomography and MR imaging in the head and neck.

Many modern surgical techniques have been developed to provide exposure or visualization of the surgical field to perform definitive treatment. The actual therapeutic part of surgery is often a small fraction of the procedure. In obtaining exposure, however, morbidity can ensue. This has led to newer techniques that use minimally invasive treatments, thus substantially decreasing overall morbidity and patient costs. By providing physicians with visualization alternatives, MR imaging and computed tomography, when combined with a therapeutic procedure, can reduce the morbidity of surgery.

Biopsy, Needle↗
PubMed1994

Difficulty in eradicating Helicobacter pylori in a population at high risk for stomach cancer in Venezuela.

The bacterium Helicobacter pylori (HP) has been implicated in the etiology of precancerous lesions of the stomach and there is evidence suggesting that it may influence the efficacy of chemoprevention of gastric cancer with vitamin C. Eradication seldom has been attempted in populations from developing countries, with a high prevalence of HP frequently resistant to metronidazole. A randomized, double-blind, controlled trial to evaluate the efficacy of colloidal bismuth subcitrate (120 mg q.i.d.) and amoxycillin (500 mg q.i.d.) in eradicating HP was conducted in 220 subjects drawn from a population with a high prevalence of metronidazole-resistant HP in Tachira state, Venezuela. One month after completion of two weeks' treatment, eradication rates of 6.5 percent in the treatment group and two percent in the placebo group were estimated on the basis of HP diagnosis in biopsies, and of 13.9 percent compared with 3.9 percent on the basis of a 14C-urea breath test, although the negative predictive value of the breath test was very low compared with HP diagnosis in biopsies. In the treatment group, particularly among males, a significant decrease in bacterial load was detected. Reasons for failure of treatment in high HP-prevalence areas are discussed, and it is suggested that primary prevention of HP infection may be the optimal approach to reducing levels of stomach cancer in these high-risk groups.

Adult↗
PubMed1993

Anticoagulant and estrogenic effects of two new 17 beta-aminoestrogens, butolame [17 beta-(4-hydroxy-1-butylamino)-1,3,5(10)-estratrien-3-ol] and pentolame [17 beta-(5-hydroxy-1-pentylamino)-1,3,5(10)-estratrien-3-ol].

The syntheses and characterizations of two new 17 beta-aminoestrogens, butolame [17 beta-(4-hydroxy-1-butylamino)-1,3,5(10)-estratrien-3-ol] and pentolame [17 beta-(5-hydroxy-1-pentylamino)-1,3,5(10)-estratrien-3-ol], are presented. Both compounds, when administered in single subcutaneous injections to male mice and rats, produce dose-dependent increases in blood clotting times that may last several days. The estrogenic effects assessed by the vaginal cornification test are of relatively short duration.

Amino Alcohols↗
PubMed1993

Laparoscopic inguinal herniorrhaphy. Techniques and controversies.

Because of the remarkable success of laparoscopic cholecystectomy, numerous investigators have attempted to duplicate this success with laparoscopic herniorrhaphy. This article presents a different view of the preperitoneal anatomy, reviews the rationale behind the various laparoscopic approaches, and presents, in detail, the laparoscopic preperitoneal repair with mesh, including complications and early recurrences. An attempt is made to put the new laparoscopic procedures into perspective with regard to economic issues and safety.

Adolescent↗