Anatomical Variants in Renal Transplantation, Surgical Management, and Impact on Graft Functionality.

INTRODUCTION: Chronic kidney disease (CKD) is a priority problem due to its high prevalence. According to the modalities of renal replacement therapy, kidney transplantation (TR) offers to be the best alternative. TR presents multiple factors of dependence of success; among them is the management of the anatomical variants of the graft and the surgical decision on the basis of these. Therefore, the objective of this study is to determine the frequency of variants in the graft, its surgical management, and the impact on the functionality of the transplanted kidney. MATERIAL AND METHODS: This was an observational, retrospective study of patients in the renal transplant unit of the Siglo XXI National Medical Center from 2002-2016. The analysis begins in the description of the population doing bivariate analysis to establish relative risks. For variables with a central tendency, the parametric tests analysis of variance, Student t paired, and unpaired will be used. In the case of nominal variables, the proportion's difference will be estimated using the chi-square test, establishing significance when P is ≤ .05. SPSS 21 software was used. RESULTS: There were a total of 773 patients, with 576 transplants from living donors and 197 from deceased donors. In the case of the artery, a greater number of variants is observed-27.8% being alive versus 17.3% of the variants found in deceased donors. For the renal vein, 12.7% of the kidneys were taken from living donor vs 6.1% from deceased donors. This required one more day of hospitalization (6 vs 7 days of single vs multiple vessels); likewise, increases in immediate post-transplant infections were 5% for single vessels vs 8% in the case of multiple variants. CONCLUSIONS: The importance of knowing the anatomical variants prior to the TR allows them to plan the potential surgical maneuvers, decreasing the times aimed at improving the immediate functionality of the renal graft, while also considering the increase in hospital expenses due to the greater number of days of hospitalization.

Specific Antigens by Federal Entity in Patients at the Transplant Unit of Specialities Hospital, National Medical Center Twenty-First Century, Mexico.

BACKGROUND: The study of the kidney transplant involves understanding the immunologic basis, such as histocompatibility and the genetic basis of a population. In Mexico, the study of the genetic basis has led to a genetic map by federal entities. METHODS: We performed an HLA study with 1,276 kidney transplant patients (recipients and donors) in the Hospital of the National Medical Center Twenty-First Century, determining HLA class I (A, B, and Cw) and class II (DRß1 and DQß1) antigens with the use of SSOP-PCR. A descriptive analysis was conducted with measures of central tendency (mean, SD). RESULTS: Of 1,276 HLA patients studied, we obtained 2,552 results for each class by the composition of the 2 haplotypes, and for HLA-Cw we processed 796 patients, for a total of 1,592 antigens for this class. We found antigens specific to each federal entity, and it was found that the Federal District had the highest number of specific antigens (10) followed by Morelos (7), Querétaro and Mexico State (3 each), and Tamaulipas, Aguascalientes, Michoacán, Guerrero, Puebla, and Oaxaca (1 each). CONCLUSIONS: The genetic map allows us to know proportions of antigens in every state in the center and south of Mexico owing to the diversity and area of influence of the National Medical Center XXIst Century, as well as the wide number of patients. Furthermore, there are still preserved proportionally distinct genetic roots in every entity.

The Most Common HLA Antigens Found in Patients With Renal Transplants at the Specialties Hospital of "La Raza" Medical Center, Mexico.

BACKGROUND: The knowledge to understand transplant acceptance or rejection derives directly from knowing its genetic material and the major histocompatibility complex involved in immune response, so it is essential to identify the most common alleles in the Mexican population. METHODS: In the northern areas of the Federal District (DF), Hidalgo, and Mexico State, we performed an analysis of HLA class I (A and B) and HLA class II (DRß1 and DQß1) with the use of the PCR-SSP process (Invitrogen). We performed measures of central tendency and percentages of common alleles in the study population. RESULTS: We analyzed 718 results of patients before renal transplantation: 313 pairs of recipients and living donors and 92 patients receiving cadaveric donation. HLA allele A 02 536 (37.32%) was the most common allele found. In HLA B, the most common allele corresponded to 35, in 321 (22.35%), which was the most polymorphic. In HLA DRß1 the most common was 04, in 447 (31.12%), which was the least polymorphic; the most common was 03, in 777 (54.10%). CONCLUSIONS: We corroborated the frequency of alleles found in the considered population, which corresponds to the northern part of Mexico City as well as the states of Mexico and Hidalgo. It was determined that there is no risk allele for developing chronic kidney disease.

The measurement of photoneutron dose in the vicinity of clinical linear accelerators.

In Brazil, the replacement of rather old cobalt and cesium teletherapy machines with high-energy (E > 10 MV) medical linear accelerators (linacs) started in the year 2000, as part of an effort by the Ministry of Health to update radiotherapy installations. Since then, the contamination of undesirable neutrons in the therapeutic beam generated by these high-energy photons has become an issue of concern when considering patient and occupational doses. The walls of the treatment room are shielded to attenuate the primary and secondary X-ray fluence, and this shielding is generally considered adequate also to attenuate neutrons. However, these neutrons are scattered through the treatment room maze and might result in a radiological problem at the door entrance, an area of high occupancy by the workers of a radiotherapy facility. This paper presents and discusses the results of ambient dose equivalent measurements of neutron using bubble detectors. The measurements were made at different points inside the treatment rooms, including the isocentre and the maze. Several radiation oncology centres, which are users of Varian Clinac or Siemens machines, have agreed to allow measurements to be taken at their facilities. The measured values were compared with the results obtained through the semi-empirical Kersey method of neutron dose equivalent calculation at maze entrances, with reported values provided by the manufacturers as well as values published in the literature. It was found that the measured values were below the dose limits adopted by the Brazilian Regulatory Agency (CNEN), requiring no additional shielding in any of the points measured.

Neutron scattering in concrete and wood: Part II--Oblique incidence.

The knowledge of neutron reflection coefficients is of practical interest when projecting the shielding of radiotherapy rooms, since it is known that about 75% of the neutrons at the maze entrance of these rooms are scattered neutrons. In a previous paper, the energy spectra of photoneutrons were calculated, when reflected by ordinary, high-density concrete and wood barriers, using the MCNP5 code, considering normal incidence and neutron incident energies varying between 0.1 and 10 MeV. It was found that the mean energy of the reflected neutrons does not depend on the reflection angle and that these mean energies are lower in wood and barytes concrete, compared with ordinary concrete. In the present work, the simulation of neutron reflection coefficients were completed, considering the case when these particles do not collide frontally with the barriers, which constitute the radiotherapy room walls. Some simulations were also made to evaluate how neutron equivalent doses at the position of the room door is affected when the maze walls are lined with neutron absorbing materials, such as wood itself or borated polyethylene. Finally, capture gamma rays dose at the entrance of rooms with different maze lengths were also simulated. The results were discussed in the light of the albedo concepts presented in the literature and some of these results were confronted with others, finding good agreement between them.

Expression of prolactin gene and secretion of prolactin by rat retinal capillary endothelial cells.

PURPOSE: Prolactin fragments inhibit blood vessel formation, whereas anti-prolactin antibodies induce angiogenesis in the cornea. Endothelial cells from brain capillaries and the umbilical vein produce prolactin, and this study was undertaken to determine whether retinal capillary endothelial cells could be a source for prolactin in the eye. METHODS: Primary cultures of rat retinal endothelial cells were investigated for the expression of prolactin mRNA by reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis and by in situ hybridization. The prolactin protein was analyzed by immunocytochemistry, enzyme-linked immunoabsorbent assay, Western blot analysis, and the Nb2-cell bioassay. The effect of prolactin and the 16-kDa prolactin fragment on retinal endothelial cell proliferation was investigated, and the expression of the cloned prolactin receptor was analyzed by RT-PCR and Southern blot analysis. RESULTS: Retinal endothelial cells expressed prolactin mRNA and full-length 23-kDa prolactin. Prolactin was observed in the cytoplasm of cells and in their conditioned medium at levels 300 times those described in endothelial cells from other vessels and species. Exogenous 16-kDa prolactin inhibited rat retinal endothelial cell proliferation, whereas 23-kDa prolactin was inactive. No evidence was obtained for the expression of the cloned prolactin receptor in these cells, but the prolactin receptor was amplified in whole rat retina. CONCLUSIONS: Endothelial cells from the microcirculation of rat retina produce and release prolactin. That the cloned prolactin receptor was not expressed in these cells argues against direct autocrine effects of prolactin. Possible paracrine effects are suggested by the expression of the prolactin receptor in retinal tissue.