Biography:

In the past J. Rovira has collaborated on articles with M.A. Martínez and J.C. Etayo. One of their most recent publications is Structural study of the frog Rana temporaria larval stomach. Which was published in journal Tissue and Cell.

More information about J. Rovira research including statistics on their citations can be found on their Copernicus Academic profile page.

J. Rovira's Articles: (10)

Structural study of the frog Rana temporaria larval stomach

AbstractThe gastric wall of Rana temporaria tadpoles consists of a well-developed mucosa and thin muscular and serosa layers. Three cellular types — mucous, ciliated and endocrine cells — make up the lining epithelium. Different types of endocrine cells exist. Argyrophylic endocrine cells can be recognized in semithin sections of plastic-embedded material while nonargyrophylic endocrine cells can only be identified under the electron microscope. Glands are composed mainly of well-differentiated oxyntic cells and, occasionally, scarce endocrine cells. Oxyntic cells show abundant mitochondria and smooth endoplasmic reticulum, but do not contain zymogen granules as do those present in adults. Secretory canaliculi with microvilli are also well-developed. The lamina propria contains numerous vascular sinuses and nerve bundles which innervate the endothelium and some endocrine cells. The neuroendocrine regulation of frog gastric functions seems therefore to have developed in young tadpoles. Nerve fibers also innervate the muscular propria, which is composed of a single layer of smooth muscle cells. Underlying the muscle, connective fibers and a flattened layer of mesothelial cells make up the serosa. In summary, the structure of the frog larval stomach shows a well-differentiated histological pattern, especially referring to surface epithelium and glands. Some of the histological traits will also be present in adult frogs while others are characteristic of the tadpole's stage.

Comparing dietary and non-dietary source contribution of BPA and DEHP to prenatal exposure: A Catalonia (Spain) case study

Highlights•Comparing dietary and non-dietary prenatal exposure to BPA and DEHP.•PBPK model predict the fetus’ toxicokinetic profile based on mother exposure.•Non-diet sources exposure contribution is smaller than diet sources.•First-pass metabolism is lacking in dermal and inhalation exposure.•More unconjugated BPA is expected due to a lack of the first-pass metabolism.

Regular ArticleCharacterization of Pancreatic Endocrine Cells of the European Common Frog Rana temporaria

AbstractTo characterize the endocrine cell types of the pancreas of Rana temporaria, conventional staining, silver impregnation, and immunocytochemical methods for light and electron microscopy have been applied to paraffin, thin and semithin sections, many of them serial pairs. Quantitative data on the frequency and distribution (insular, extrainsular among the exocrine cells, or within the pancreatic ducts) of each endocrine cell type are also reported. Four distinct endocrine cell types have been identified: insulin (B) cells, which are also immunoreactive for [Met]enkephalin; glucagon/PP (A/PP) cells, also immunoreactive for GLP1; somatostatin (D) cells; and a fourth endocrine-like cell type (X cells) of unknown content and function. X cells display characteristic ultrastructure and tinctorial traits but are nonimmunoreactive for all of the 37 antisera tested. The presence of [Met]enkephalin in amphibian pancreatic endocrine cells is now reported for the first time. Almost half (44.9 ± 7.9) of the total endocrine cell population lies outside the islets, mainly spread among the exocrine cells. Approximately 37.2 ± 4.6% of the total endocrine cell population was immunoreactive for insulin, 48.8 ± 6.9% was immunoreactive for glucagon/PP, and 14.0 ± 4.9% was immunoreactive for somatostatin; 79.2 ± 6.4% of glucagon/PP cells are found within the exocrine parenchyma, representing the majority (86.4 ± 4.3%) of extrainsular endocrine component. On the contrary, most B cells (94.2 ± 2.1%) are located within the islets; 30.8 ± 12.9% of D cells are found outside the islets.

Adrenocortical tumors in childhood: A report of four cases

In the last 10 years, four children with adrenocortical tumors were treated in our hospital. Three of them had symptoms of adrenogenital virilizing syndrome, and another, nonfunctional, was found during a routine examination. A diagnosis of adrenocortical tumor was established given the symptoms, hormonal tests, and radiologic studies. Two of the tumors were located in the left side, and the histologic diagnosis was pleomorphic cortical adenoma; the ones that affected the right side were adenocarcinomas. All the patients were treated by surgery and none received chemotherapy. At both presurgical and postsurgical stages, the patients were treated with cortisol. All four children have had a favorable course, with normal growth and the disappearance of pubic hair and hirsutism; however, macrogenitals still persist.

Segmental dilatation of the duodenum

In this article two cases of idiopathic duodenal dilatation are described. These cases meet the present criteria for segmental dilatations of the intestine. The onset of the clinical features was acute in one case and chronic in the other. However, the radiological images were similar in both cases and provided the diagnosis. Surgical treatment consisted of duodenal resection and tapering and was curative in one case. The other patient died shortly after surgery. The duodenal specimens showed normal threelayer duodenal architecture in the pathology study. The intramural nervous plexi were unimpaired. Angiodysplasia was found in one case. Vascular abnormalities were also found in 10 other segmentary intestinal dilatations reported in the literature. The surgical implications of this new localization of segmentary intestinal dilatation are analyzed.

ImmunosuppressionSirolimus Monotherapy as Maintenance Immunosuppression: Single-Center Experience in 50 Kidney Transplant Patients

AbstractIntroductionChronic allograft nephropathy, cardiovascular mortality, and posttransplant malignancy are complications of conventional immunosuppression after kidney transplantation. We reported the feasibility of maintenance monotherapy with sirolimus (SRL) in a pilot experience. The aim was to study safety and feasibility of SRL maintenance monotherapy in 50 kidney transplant patients.MethodsAll patients from our center with at least 6 months follow-up on SRL monotherapy were included. During the first month after start of SRL monotherapy, follow-up visits were performed weekly, then each month for the following 2 months. Each follow-up visit included a physical exam and laboratory screening.ResultsMean follow-up on SRL monotherapy was 34.7 ± 14.9 months. The time between transplantation until start of monotherapy was 7.7 ± 3.3 years. No rejections occurred. During follow-up, two patients died of cardiovascular disease (already diagnosed before monotherapy); one, of previously diagnosed posttransplant malignancy and one, of hepatitis C–related liver failure. Glomerular filtration rate (GFR) was 53 mL/min  ⁎  1.73 m2 at start of monotherapy and 50 mL/min  ⁎  1.73 m2 after 4 years. Proteinuria was 632 ± 562 mg/24 hours at 4 years. During the follow-up, no significant changes in the lipid profile, glycemia, or hemoglobin occurred.ConclusionsSirolimus monotherapy is safe in a selected group of immunological low-risk patients without increasing the risk of rejection.

Mammalian Target of Rapamycin and Diabetes: What Does the Current Evidence Tell Us?

AbstractNew-onset diabetes mellitus after transplantation (NODAT) is a serious complication in organ transplantation; not only does it enhance the risk of graft dysfunction, it also increases cardiovascular morbidity and mortality. The mammalian target of rapamycin (mTOR) is regulated independently by insulin, amino acids, and energy sufficiency. It integrates signal from growth factors, hormones, nutrients, and cellular energy levels to regulate protein translation and cell growth, proliferation, and survival. In addition, mTOR generates an inhibitory feedback loop on insulin receptor substrate (IRS) proteins. Therefore, it was suggested that mTOR might link nutrient excess with both obesity and insulin resistance. In this review, we summarize the role of mTOR and its inhibitor sirolimus (SRL) on chronic hyperglycemia and insulin resistance in β cells, adipose tissue, liver, and muscle. We further hypothesize, based on data from the literature and generated in our laboratory, that SRL could counteract the development of NODAT in stable glucose homeostasis due to its positive effects on insulin-stimulated glucose uptake, whereas in conditions that require an adaptive β cell proliferation (such as pregnancy and weight increase), the administration of SRL might have effects that would promote the development of NODAT. Therefore, it seems crucial for patient outcome to consider these potentially contrasting effects of SRL.

Prevalence and quantification of Shiga-toxin producing Escherichia coli along the lamb food chain by quantitative PCR

AbstractShiga-toxin producing Escherichia coli (STEC), which is responsible for numerous food-borne disease outbreaks, is the most important human pathogen found in ruminants. In this study, conventional microbiology and quantitative PCR (qPCR) were used to detect and quantify STEC along the lamb food chain, from slaughterhouses to butcheries, in both meat and environmental samples. Microbial Assessment Scheme (MAS) was used to select Critical Sampling Locations (CSLs) in each establishment. The rpoB gene was used to enumerate total E. coli by qPCR, whereas the genes stx1, stx2 and eae were directly amplified for quantification of E. coli virulent populations. The results obtained show that E. coli carrying all three virulence genes were the most prevalent in slaughterhouses (69%), whereas E. coli with the eae gene alone were found more frequently in the processing plant (32%), and stx1- and stx2-positive E. coli were predominant in butcheries (9–10%). E. coli virulent populations were not common in butcheries. Samples determined to be positive for E. coli virulent populations after enrichment were quantified by qPCR and compared with conventional microbiology counts using validated methods. The results showed a higher number of positive CSLs for E. coli virulent populations, and higher counts were obtained when qPCR was used than when using conventional methods.

Control of Escherichia coli and Listeria monocytogenes in suckling-lamb meat evaluated using microbial challenge tests

Highlights•Pathogen control of suckling-lamb meat is needed.•MAP/VP and protective culture against E. coli and L. monocytogenes were studied.•E. coli is reduced by MAP/VP, chilling storage and native lactic acid bacteria.•L. monocytogenes is reduced by 60%CO2 and 6 log cfu/g Lc. pseudomesenteroides PCK18.•6 log cfu/g of Lc. pseudomesenteroides PCK18 caused unpleasant lactic smells.

Randomized clinical trial comparing endoscopic treatment with dextranomer hyaluronic acid copolymer and Cohen's ureteral reimplantation for vesicoureteral reflux: Long-term results

AbstractPurposeTo compare efficacy of Cohen's ureteral reimplantation and endoscopic treatment with Dx/HA in patients with primary VUR grades II, III and IV.MethodsFrom April 2002 to June 2004, patients over 1 year old with VUR grade I, II, III or IV were included. Patients were randomized into two groups: endoscopic treatment (ET) or ureteral reimplantation (UR). In the ET group, an ultrasonography study was performed 24 h and 1 month after surgery, and two voiding cystourethrographies at 3 and 6 months post treatment. In the UR group, an ultrasonography study was done 7 days and 1 month after surgery and a micturial cystography 6 months post surgery. A postoperative nuclear direct cystogram was performed 5 years later in both groups.ResultsA total of 41 patients were included in this study: in ET 22 patients with 35 refluxing ureters and in UR 19 patients with 32 refluxing ureters. The VUR grades in ET were: 16 grade II, 16 grade III and 3 grade IV; and in UR: 15 grade II, 12 grade III and 5 grade IV. VUR was resolved in 91% (32/35) of ET (28% of ureters needed a second injection), and in 100% of UR group. Five years after the procedure, VUR was still resolved in 30/32 of ET and 32/32 of UR.ConclusionShort- and long-term follow up shows that multiple endoscopic treatment of VUR grades II, III and IV with Dx/HA is as effective as ureteral reimplantation.

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