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Biomedical subjects

C Rubio

Publications and source records attributed to C Rubio.

At least 73 records · Page 4Linked to original sources
PubMed1998

Multicomponent recycled plastics: considerations about their use in food contact applications.

Two multicomponent post-use recycled plastics named as NPP40A3 (formulated with 85% HDPE and 15% of a PP-PS-PVC mixture) and NPP40A6 (formulated with 80% NPP40A3, 10% ABS and 10% HIPS), both of them with 3.1% of plasticizer and 0.6% of stabilizer to obtain a better final product, have been analysed. Plastics were extracted both with dichloromethane and methylbenzene, and analysed by HPLC and GC-MS to identify the maximum possible number of compounds. Major additives quantified were di(ethylhexyl)phthalate (3.262% and 2.955% respectively) and Irganox 1010 (0.473% and 0.498% respectively). Several degradation compounds have been detected. In order to check if these plastics could be used in food contact applications, global and specific migration tests have been applied. The results obtained are discussed.

Chemical Phenomena↗
PubMed1998

Type I Helicobacter pylori shows Lewis(b)-independent adherence to gastric cells requiring de novo protein synthesis in both host and bacteria.

Type I Helicobacter pylori strains frequently recognize the Lewisb (Leb) blood group antigen. This binding property and expression of the Leb oligosaccharide were required for adherence to fixed normal or pathologic gastric tissue. In contrast, both type I and type II strains adhered to cultured cells in the absence of the Leb epitope. For the gastric cell line AGS, adherence was significantly higher when viable type I strains were allowed to interact with viable AGS cells compared with fixed cells. The observation that chloramphenicol and cycloheximide, inhibitors of bacterial and eukaryotic protein synthesis, respectively, significantly reduced adherence of type I but not type II isolates suggests that in type I strains, adherence depends on the up-regulation of one or more host cell receptors triggered by the bacterium.

Bacterial Adhesion↗
PubMed1998

DGGE screening of mutations in mismatch repair genes (hMSH2 and hMLH1) in 34 Swedish families with colorectal cancer.

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominantly inherited syndrome which confers an increased risk for colorectal cancer and endometrial cancer as well as other tumors. It is caused by germline DNA mismatch repair (MMR) gene mutations in five MMR genes, hMSH2, hMLH1, hPMS1, hPMS2 and hMSH6. Finding mutations in these high risk families means that you can offer presymptomatic carrier diagnosis and thereby identify individuals with a very high risk for cancer. These persons benefit from counseling and should be offered surveillance. We have used DGGE to screen members from 34 families for mutations in hMLH1 and hMSH2. Six mutations in five families were found, five of these mutations are new. Besides, three new polymorphisms were identified. The mutations were found in two of seven Amsterdam criteria HNPCC families and in three of four families with at least one case of early onset of CRC (before 35), suggesting there are appropriate families to be chosen for mutation screening in MMR genes.

Adaptor Proteins, Signal Transducing↗
PubMed1998

The relationship between climate and the distribution of Culicoides imicola in Iberia.

The biting midge Culicoides imicola was captured at 17 of 27 farms in Spain and Portugal during a survey of its distribution following outbreaks of African horse sickness in Iberia that occurred between 1987 and 1990. Farms were sampled approximately twice weekly from October 1992 to February 1995. Farms were widely spaced apart (maximum 850 km) and had considerable variation in climate. Across sites, summer temperatures ranged from 18.3 degrees C-27.2 degrees C; in winter the range was 4.4 degrees C-11.6 degrees C. Relative humidities in summer ranged from 37.2% to 90.1%. Proximity to southern Spain (Seville) was the most significant predictor of the presence/absence of C. imicola, but high summer temperatures and possibly dry summer conditions, were also important. Vila Nova de Milfontes in Portugal, where C. imicola was abundant and the climate is relatively cool, was an exception to the climatic trends at the other 26 sites. This exception points to a lack of knowledge of climatic requirements for immature development of C. imicola. The absence of C. imicola from the three most easterly sites, which have apparently favourable climates, suggests a relatively recent invasion by this species into Iberia.

African Horse Sickness↗
PubMed1998

Chronic hepatitis C: treatment comparison between 3 and 5 million units of interferon alpha-2b.

Interferon (IFN) is the only drug that has been approved by the FDA for therapy of chronic hepatitis C. However, optimal dose and duration of therapy are still controversial. This study compares the effectiveness of treatment of chronic hepatitis C patients with 3 vs. 5 million units (MU) of recombinant alpha-interferon 2-b three times per week. We also evaluated the relapse rate with a shorter 12 week-course of therapy in those patients who had normalization of aminotransferases by week 12. Seventy-five patients were randomized to receive either 3 vs. 5 MU of IFN; seventy-two completed the study. A complete response was seen in 11/35 (31%) of those treated with 5 MU vs. 13/37 (35%) in the 3 MU dose (p = 0.74). Patients were followed after IFN was withdrawn and only 2 had persistently normal aminotransferases. Analysis of multiple variables was done to predict response to IFN and only elevations of GGT, ferritin and alkaline phosphatase were found to be predictors of a poor response. Therefore, we recommend initial therapy with 3 MU of IFN for a longer period than 12 weeks in patients who show a response.

Adult↗
PubMed1997

Increased incidence of disomic sperm nuclei in a 47,XYY male assessed by fluorescent in situ hybridization (FISH).

Using triple-colour fluorescent in situ hybridization in decondensed sperm heads, we assessed the sex-chromosome distribution in spermatozoa from a 47,XYY male compared with controls. The incidence of spermatozoa with 24,XY (0.30%) and 24,YY (1.01%) disomy was significantly higher than in our control series. Diploid meiocytes present in the ejaculate were mainly 47,XYY (60.6-86.7%), and haploid meiocytes were mainly 24,XY (78.1%).These results suggest that, although the extra Y chromosome is thought to be eliminated during spermatogenesis, XYY germ cells can complete meiosis and produce disomic spermatozoa.

Adult↗
PubMed1997

Idiopathic pneumonia syndrome after high-dose chemotherapy for relapsed Hodgkin's disease.

The risk of idiopathic pneumonia syndrome (IPS) in patients with Hodgkin's disease (HD) undergoing high-dose chemotherapy (HDC) is significant, and once developed IPS is potentially fatal. The aim of this study was to quantify this risk accurately and determine prognostic factors for its development and course. Using a computerized database, all patients with HD treated with BCNU (carmustine) containing HDC and haematopoietic support at The Royal Marsden between November 1985 and March 1994 were identified. Patient characteristics, previous treatments, disease status at HDC, dose of BCNU, incidence and severity of IPS and survival were all determined and analysed. During the study period, 94 patients received HDC, of whom 26 (28%) had a first episode of IPS within a year of HDC and 23 within 6 months. The median time to presentation after HDC was 93 days (range 12-336 days). The only factors that significantly increased the risk of developing IPS on multivariate analysis were dose of BCNU (P for trend = 0.03) and female sex (P = 0.04). Of these 26 patients, 14 had complete resolution of all symptoms, three had persisting pulmonary symptoms at 6 months and the remaining nine died of IPS at a median of 74 days (19-418 days). All the patients who died from IPS had the first symptoms within 6 months of HDC and all received doses of BCNU > 475 mg m(-2) (P for trend = 0.001). For women receiving > 475 mg m(-2) the risk of death was significantly higher than for men (P = 0.035) but not for those receiving < 475 mg m(-2). Previous lung disease, persisting residual disease before HDC, previous bleomycin or previous mantle radiotherapy did not increase either the incidence of IPS or risk of a fatal outcome. We conclude that the main avoidable risk factor for fatal IPS after HDC is dose of BCNU, and this is especially true for women. If < 475 mg m(-2) is given, even patients with previous mantle radiotherapy and/or previous bleomycin have a very low risk of developing fatal lung toxicity if lung function tests are normal.

Adolescent↗
PubMed1997

Small colorectal serrated adenomas: endoscopic findings.

BACKGROUND AND STUDY AIMS: Serrated adenomas are a distinct form of colorectal neoplasia. Several reports have indicated that serrated adenomas may give rise to invasive adenocarcinoma. The present study describes the endoscopic findings in 54 colorectal serrated adenomas detected in 35 patients. PATIENTS AND METHODS: Thirty-five of 1225 patients (2.9%) who underwent colonoscopy during 1993 in the gastrointestinal endoscopy section at Karolinska Hospital (22 men, 13 women; mean age 68 years, range 49-84 years) were found to have a total of 182 polyps, including 118 adenomas and 64 hyperplastic polyps at histopathology. Fifty-four of the 118 adenomas (46%) were of the serrated type. In two of the 35 patients, two large exophytic colorectal adenocarcinomas were also present. RESULTS: Twenty-nine of the serrated adenomas (53.5%) were flat, 23 were sessile (42.5%), and two were pedunculated (4%). The mean sizes of the flat and sessile lesions were 3.5 mm (range 2-10 mm) and 5.9 mm (range 2-20 mm), respectively. The endoscopic appearance of serrated adenomas of 5 mm or less (n = 39, 72%) was similar to that of hyperplastic polyps. Forty-two (78%) of the lesions were located in the sigmoid and rectum. Fifty-one lesions showed low-grade dysplasia (including one with microinvasive carcinoma), and the remaining three had high-grade dysplasia. CONCLUSIONS: The study suggests that small polyps with a hyperplastic appearance should not be regarded as innocuous, since they may represent serrated adenomas carrying a malignant potential.

Adenoma↗
PubMed1997

Rectal tumours--MR imaging with endorectal and/or phased-array coils, and histopathological staging on giant sections. A comparative study.

OBJECTIVE: To investigate the accuracy of MR imaging in the preoperative staging of patients with clinically resectable rectal tumours. MATERIAL AND METHODS: Forty-eight consecutive patients with rectal tumours were examined, 29 with a pelvic phased-array coil and 19 with a multi-coil arrangement including a pelvic phased-array coil and an endorectal coil. MR images and histopathological specimens and sections were reviewed independently and tumours were staged according to the TNM classification. RESULTS: A more complete visualisation of the various layers of the rectal wall was achieved on the endorectal MR images than on the pelvic phased-array images. The sensitivity of MR in correctly staging T3 tumours compared with histopathology was 81% with a specificity of 82%. Penetration of the rectal wall was predicted with a sensitivity of 82% and a specificity of 87%. Sensitivity and specificity in predicting lymph node metastases was 83% and 74% respectively. CONCLUSION: MR imaging with both pelvic phased-array and endorectal coils allowed the preoperative staging of rectal tumours with a high degree of accuracy.

Adult↗
PubMed1997

The impact of endometriosis in couples undergoing intracytoplasmic sperm injection because of male infertility.

To assess the impact of endometriosis on intracytoplasmic sperm injection (ICSI) outcome, we have retrospectively evaluated 980 ICSI cycles, comparing the results of women with and without endometriosis. A total of 101 cycles was identified in which various degrees of endometriosis were involved, and in the remaining 879 cycles, male infertility was the only cause of infertility. Ejaculated spermatozoa were microinjected in all cycles. There was a significant reduction (P = 0.004) in the number of oocytes retrieved from women with endometriosis as compared to those without endometriosis. However, there were no significant differences in either fertilization or pregnancy and implantation rates between women with or without endometriosis. We conclude that the presence of endometriosis in patients undergoing ICSI because of severe male infertility does not affect fertilization, pregnancy and implantation rates, although significantly fewer oocytes are retrieved from patients with endometriosis.

Adult↗
PubMed1997

Origin of tripronucleate zygotes after intracytoplasmic sperm injection.

Zygotes morphologically classified as tripronuclear (3PN) after intracytoplasmic sperm injection (ICSI), which are thought to be digynic in their origin, were studied by fluorescent in-situ hybridization (FISH). FISH results allowed us to assess the suspected ploidy after morphological evaluation of the zygote and to determine the origin of the third pronuclei. Our results show that, firstly, 36% of those zygotes classified as 3PN following their morphological evaluation were, in fact, diploid, and secondly, the main cause for triploidy after ICSI is the non-extrusion of the second polar body.

Cell Nucleus↗
PubMed1996

Fertilization after intracytoplasmic sperm injection with cryopreserved testicular spermatozoa.

OBJECTIVE: To assess the possibility of cryopreserving testicular tissue extracted sperm for intracytoplasmic sperm injection (ICSI). DESIGN: A report of two cases. Our study was approved by the Ethical Committee at the Instituto Valenciano de Infertilidad. SETTING: In vitro fertilization program at the Instituto Valenciano de Infertilidad. PATIENTS: Two azoospermic patients with severe spermatogenic failure but with focal spermatogenesis on testicular biopsies. In both cases, a first ICSI attempt with fresh testicular biopsy extracted sperm was unsuccessful. INTERVENTIONS: Cryopreservation of testicular spermatozoa in 100-micro L "pills." Intracytoplasmic sperm injection with thawed testicular spermatozoa. MAIN OUTCOME MEASUREMENTS: Fertilization rate, cleavage rate, embryo quality, clinical pregnancy. RESULTS: Fertilization rates were 36 percent and 100 percent after ICSI with fresh testicular spermatozoa, and 63 percent and 57 percent after ICSI with cryopreserved testicular sperm. In both cases, cleavage rates and embryo quality were similar when using fresh and cryopreserved testicular spermatozoa. No clinical pregnancies were achieved. CONCLUSION: High fertilization rates can be obtained after ICSI with frozen-thawed testicular tissue extracted spermatozoa. Cryopreservation of testicular sperm may avoid repetition of testicular biopsies in azoospermic patients in whom the only source of spermatozoa is the testicle.

Adult↗
PubMed1996

Small, flat colorectal neoplasias in long-standing ulcerative colitis detected by high-resolution electronic video endoscopy.

BACKGROUND: High-resolution video endoscopy complemented with chromoscopy allows for more detailed visualization of the colonic mucosal surface. METHODS: Using high-resolution video endoscopy and chromoscopy, we investigated 85 patients with extensive ulcerative colitis with a disease duration of at least 10 years who were taking part in a cancer surveillance program. RESULTS: In 38 of the 85 patients, 104 polyps were detected at endoscopy. Seventy-seven (74%) of the 104 polyps were endoscopically flat, 21 (20%) were sessile, 3 (3%) were pedunculated, and 3 (3%) had no recorded morphology. Twenty-three (22%) polyps were neoplastic (15 flat, 5 sessile, 2 pedunculated, 1 not recorded). Low-grade dysplasia was found in 21 of the 23 neoplastic polyps and high-grade dysplasia in the remaining 2 (1 flat tubular adenoma and 1 sessile villous adenoma with invasive growth). Flat polyps were small, with a diameter of 5 mm or less in 73% (n = 56) of cases. At histology flat polyps revealed either flat adenomas (n = 11; 14.3%), tubular or villous structures with dysplastic cells at the lower part of the crypts (n = 4; 5.2%), flat hyperplastic polyps (n = 26; 34%), inflammatory mucosa (n = 5; 6.5%), or mucosa in remission (n = 31; 40%). CONCLUSION: The use of high-resolution video endoscopy complemented with chromoscopy in ulcerative colitis enables the detection of flat neoplastic polyps. The existence of those hitherto undetected neoplasms in ulcerative colitis and their possible role in the histogenesis of colorectal cancer in ulcerative colitis deserve further investigation.

Adenoma↗
PubMed1996

Intracytoplasmic sperm injection: a treatment for extreme oligospermia.

PURPOSE: We evaluated the efficacy of intracytoplasmic sperm injection in patients with extreme oligospermia. MATERIALS AND METHODS: A total of 67 intracytoplasmic sperm injection cycles was attempted in 58 infertile couples in which the husbands had extreme oligospermia (less than 100,000 spermatozoa per ml. ejaculate). RESULTS: Fertilization was achieved in 65 of 67 cycles. Mean fertilization rate per cycle was 66.4%. A total of 18 clinical pregnancies was obtained, for a pregnancy rate of 26.8% per started cycle. There were 4 miscarriages and 8 live births from 5 deliveries. Nine pregnancies are ongoing. CONCLUSIONS: Intracytoplasmic sperm injection in patients with extreme oligospermia is associated with high fertilization rates and offers the chance of pregnancy to these otherwise intractably infertile couples.

Adult↗
PubMed1996

Fetal megacystis at 10-14 weeks of gestation.

During the study period, 24,492 pregnant women attended the Harris Birthright Research Centre at 10-14 weeks of gestation, at which time, in addition to the measurements of nuchal translucency thickness and crown-rump length (CRL), data on fetal abnormalities were recorded onto a computer database. Cases of megacystis were identified and the records were reviewed. Additionally, the relationship of the longitudinal bladder diameter with the CRL and the bladder diameter/CRL ratio (expressed as a percentage) were examined with the use of data from 300 normal fetuses at 10-14 weeks. Megacystis was present in 15 of the 24,492 pregnancies (1 in 1,633) and in these cases the minimum longitudinal bladder diameter was 8 mm and the minimum bladder diameter/CRL ratio was 13%. In the 300 control fetuses the bladder was visualized in 278 (92.7%) of the cases and the longitudinal bladder diameter increased with the CRL (bladder diameter = 0.065 x CRL - 0.69; r = 0.47, p < 0.001), none of the measurements was more than 6 mm and the median bladder diameter/CRL ratio was 5.4% (range 0-10.4%) which did not change significantly with gestation (r = 0.1, p = 0.09). The bladder was visible in all cases with a minimum CRL of 67 mm. In three of the 15 cases with megacystis, there were chromosomal abnormalities. In the chromosomally normal group, there were seven cases with spontaneous resolution, whereas in four cases there was progression to severe obstructive uropathy. The bladder diameter was 8-12 mm and the bladder diameter/CRL ratio 13-22% in all cases with resolution and in one case with progressive megacystis; in the other three cases with progressive obstruction, the bladder length was more than 16 mm and the bladder diameter/CRL ratio was more than 28%.

Crown-Rump Length↗
PubMed1996

Pregnancies after intracytoplasmic sperm injection with cryopreserved testicular spermatozoa.

In 25 patients (14 suffering from obstructive azoospermia, six from non-obstructive azoospermia, three from asthenoazoospermia and two from absence of ejaculation) spermatozoa were extracted from testicular biopsies. Intracytoplasmic sperm injection (ICSI) with fresh testicular spermatozoa was performed in 18 cases; spermatozoa in excess were cryopreserved in pills. No pregnancies were achieved. In the remaining seven patients, testicular spermatozoa were retrieved and cryopreserved during a diagnostic testicular biopsy. After thawing, sperm motility was assessed in 17 cases (68%), and 18 ICSI with cryopreserved testicular spermatozoa were performed. The mean two-pronuclear (2PN) fertilization rate was 59%, the mean cleavage rate was 92%, and six clinical pregnancies were achieved, all of them still ongoing (pregnancy rate 33%). A comparison of the results of ICSI carried out with fresh or cryopreserved testicular spermatozoa showed that the mean 2PN fertilization rates per cycle (53 compared with 55%), mean cleavage rates per cycle (99 compared with 96%) and embryo quality were not significantly different. In conclusion, cryopreservation of testicular spermatozoa is feasible, even in patients with non-obstructive azoospermia, and the results of ICSI with frozen-thawed testicular spermatozoa are similar to those obtained using fresh testicular spermatozoa. Cryopreservation of testicular spermatozoa may avoid repetition of testicular biopsies to retrieve spermatozoa for successive ICSI cycles in patients in whom the only source of motile spermatozoa is the testicle.

Adult↗