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Biomedical subjects

H Rios

Publications and source records attributed to H Rios.

12 recordsLinked to original sources

Early posttransplant lymphoproliferative disease in pediatric liver transplant recipients.

Among 23 pediatric patients who underwent orthotopic liver transplant (OLT), we report two (11 and 26 months old) with posttransplant lymphoproliferative disease (PTLD) that occurred in the early posttransplantation period. They were Epstein-Barr Virus (EBV)-negative and received graft from EBV-positive donors. The surveillance for EBV viremia using serial EBV polymerase chain reaction determinations in the peripheral blood was positive at 10 and 90 days after OLT concomitant with symptoms of primary infection, both patients were treated with gancyclovir. The patients should progression to a Burkitt's and a non-Hodgkin's lymphoma that appeared 3 months posttransplantation. They were treated by withdrawal of immunosuppression and six courses of cyclophosphamide as well as anti-CD20 monoclonal antibody (Rituximab) every 21 days. One patient experienced acute graft rejection, which resolved with steroids and low doses of tacrolimus, she is free of disease at 24 months after the end of treatment. The other patient relapsed with a cerebral lymphoma, receiving aggressive chemotherapy, but died due to sepsis. In conclusion, PTLD occurred among in 2/23 patients who underwent OLT and appeared in the first quarter post OLT. The risk factors associated with early PTLD were primary EBV infection after OLT, young age, and EBV-negative recipient receiving a transplant from an EBV-positive donor. Antiviral treatment alone was inefficient; withdrawal of immunosuppression and courses of Rituximab and cyclophosphamide were well tolerated and controlled PTLD. The risk of graft rejection was increased by withdrawal of immunosuppression. One patient died.

Biliary Atresia↗

WR-2721 (amifostine, ethyol) prevents motor and morphological changes induced by neonatal X-irradiation.

Neonatal X-irradiation induces permanent abnormalities in cerebellar cortex cytoarchitecture and neurochemistry, as well as impairment in motor gait. The aim of the present work was to examine the potential protective properties of WR-2721 (Amifostine, Ethyol), a free radical scavenger, against the above mentioned alterations by using a previously described neuroprotection assessment protocol. Pre-irradiation treatment with amifostine was effective in partially preventing the cerebellar morphological damage and the motor gait impairment induced by ionizing radiation. No changes in cerebellar noradrenaline (NA) levels were detected in amifostine-treated irradiated animals. These results suggest that it is possible to counteract radiation-induced damage in the cerebella and motor gait of neonatal rats through oxygen free radical scavenger administration prior to irradiation. The presence of the agent before the injury occurs, favors the efficacy of amifostine neuroprotective activity. Clinical implications of this model are related to the daily exposure of many people to different sources of radiation (accidental, diagnostical or therapeutical).

Abnormalities, Radiation-Induced↗

Healthcare reform in Puerto Rico. Managed care in a unique environment.

To reduce healthcare costs, Puerto Rico has adopted an innovative managed-care program to replace its old public healthcare system. Under the new program, healthcare funding for the medically indigent is being transferred from government-run hospitals and clinics to contracted private insurers who provide a wide range of services on a capitated payment plan. This well-planned initiative addresses the need to cut healthcare costs in Puerto Rico, but whether it will successfully meet the healthcare needs of beneficiaries in the long run is up for debate.

Health Care Reform↗

Development of GABA binding sites in chick embryo optic lobe: effect of triton X-100.

The temporal course of the development of GABA receptor sites in chick optic lobe was studied as a parameter of neuronal differentiation in the central nervous system. At 10 days of incubation, specific [3H]GABA binding was of 0.08 pmol/optic lobe and increased 7-8 fold between 12 and 16 days of incubation, reaching at 16 days a value of 0.60 pmol/optic lobe. This coincides with the period of arrival of the retinal fibers to the optic lobe. After this stage, the number of GABA binding sites decreased to a value of 0.35 pmol/optic lobe at hatching. After hatching a new increase appeared which reached at 5 days post-hatching a value of 0.87 pmol/optic lobe. Scatchard analysis of the saturation binding data obtained at 16 days of incubation and at hatching revealed the presence of two binding sites: one with high affinity and the other with low affinity, while at 12 days of incubation, the earliest stage examined, only the low-affinity binding site appeared. The high-affinity binding site for [3H]GABA was inhibited by muscimol, GABA, and bicuculline (IC50: 0.006, 0.002 and 10 microM, respectively). These values correspond to the potencies shown by those compounds in the binding to the synaptic GABA receptor. Treatment of the synaptic membranes with Triton X-100 showed a marked increase in the amount of specific [3H]GABA binding after 16 days of incubation reaching a 3-fold increase at hatching. These results suggest that endogenous inhibitors of the higher affinity binding site, probably appear during this period.

Animals↗

Transcystic cholangiogram access via rubber band with early withdrawal after liver transplantation: a safe technique.

OBJECTIVE: Since different techniques have been described for cholangiogram access after liver transplantation, we compared two different methods for patients with duct-to-duct biliary anastomoses. METHODS: Adult liver transplant patients from program inception in 1993 to May 2003 in whom a duct-to-duct biliary anastomosis with a T-tube choledochostomy were compared with those having a transcystic duct catheter using a rubber band. We excluded 10 patients in which a different technique was used or graft or patient survived less than 21 days. Group A (n = 28,) had a number 10 T-tube exteriorized through the recipient main bile duct; and group B (n = 33) a number 5 Bard ureteral stent tied to the cystic stump with reabsorbable suture and secured with a hemorrhoidal rubber ligature. RESULTS: The biliary complication rate was lower among the transcystic catheter group (9.1%, 3/33) compared to the T-tube group (35.7%, 10/28). Postcatheter withdrawal peritonitis was present in two patients in the T-tube group, one of whom required emergency laparotomy. A satisfactory postoperative cholangiogram was obtained in both groups. The transcystic catheter was withdrawn on average at 29 days, compared to 136 days in the T-tube group. CONCLUSIONS: Both techniques are equally effective in obtaining a satisfactory postoperative cholangiogram. However, the transcystic catheter technique allows a significantly earlier withdrawal with fewer complications compared to the T-tube technique.

Adult↗

Rapid steroid taper and neoral monotherapy in liver transplantation in Chile: a step in the right direction?

UNLABELLED: Diabetes, hypercholesterolemia, hypertension, obesity, osteopenia, and increased risk of viral recurrence are among the complications associated with posttransplant steroid use. Steroid withdrawal or rapid taper has been reported to be safe. The aim of this study was to compare the rejection incidence and severity among patients treated with two different steroid taper strategies. METHODS: This retrospective study included all the adult liver transplant recipients since the program's inception from 1993 to January 2002. The minimum follow-up was 1 year. Exclusions included patients receiving an immunosupressive regimen other than mycophenolate mofetil, steroids, and Neoral, or suffering an autoimmune etiology, or displaying patient or graft survival less than 1 year. The incidence and severity of rejection episodes were compared between the two groups of steroid taper protocols: group A received methylprednisolone (1 g) intraoperatively with a slow taper to 10 mg prednisone per day at 1 year. Group B received methylprednisolone (2 g) intraoperatively followed by a rapid reduction with intention to withdraw by month 4, continuing on Neoral monotherapy. Rejection diagnosis was made on histological bases. RESULTS: One-month and 1-year rejection rates were 47% and 53%, respectively, among the rapid taper group with Neoral monotherapy, which was similar to 60% and 64%, respectively, in the slow taper group. Rejection severity was also comparable between the two groups. CONCLUSIONS: Patients treated with a rapid steroid taper protocol followed by Neoral monotherapy or a slow taper protocol showed similar acute rejection incidences and severities. Their survival rates were also comparable. Further study is necessary to evaluate the impact of rapid steroid taper to prevent the complications of steroid use.

Adrenal Cortex Hormones↗

Clinical characterization and survival of adult patients awaiting liver transplantation in Chile.

Liver transplantation has become widely used for patients with decompensated disease. Because of the shortage of donors, each year more patients die on the waiting list. Our aim was to characterize and evaluate the final outcomes of all listed candidates for liver transplantation during a 34-month period. We retrospectively evaluated all adults listed between January 2000 and November 2002. Sixty-three patients (37 women, mean age 45.8 years) were listed: 48 due to chronic liver disease and 15 for a highly urgent transplantation due to acute liver failure. The main etiology of chronic disease was alcoholic (22%) or primary biliary cirrhosis (17%). Of 52 chronic patients, 26 (50%) were transplanted with a mean waiting time of 168 days. Among the others, 8 died (15%) while awaiting transplantation, 3 (5%) were removed from the list, and 15 patients still await transplantation (28%). Among acute liver failure patients, the main etiologies were autoimmune (25%) and medication induced (25%). Of 15 acute patients, 6 (37.5%) have been transplanted at a mean waiting time of 6.8 days with 100% survival posttransplantation. In this cohort, 6 patients (37.5%) died while awaiting liver transplantation, and 4 (25%) survived with medical support. In conclusion, the severity of liver disease and death rate among our waiting list was similar to that observed in developed countries. It seems reasonable to review our current allocation system based on waiting time on the list. We will have to decide whether to transplant sicker patients or those with hepatocarcinoma (as in the United States recently with the MELD system), thereby possibly decreasing the mortality rate on the waiting list at the expense of higher costs and more difficult postoperative care or to just keep our current policy.

Adult↗

Predictive models in cirrhosis: correlation with the final results and costs of liver transplantation in Chile.

Medical scores for predicting survival are essential to stratify patients with end-stage liver disease (ESLD) for prioritization for liver transplantation (OLT). Recently the UNOS has adopted the Mayo Model for End-stage Liver Disease (MELD) score as the basis for liver allocation in the United States. We retrospectively evaluated and assessed the prognostic impact, the length of stay (LOS), and hospital charges for OLT using two severity scores (Child-Turcotte-Pugh [CTP] versus MELD) to stratify cirrhotic patients before OLT. Twenty-six consecutive adult cirrhotic patients (11 women, mean age 46 years) underwent LT between 2000 and 2002. The main causes for transplantation were alcohol and primary biliary cirrhosis. The mean CTP and MELD scores at the moment of listing for OLT were 8.9 and 16.3 points, respectively. The best discriminative values with prognostic impact in terms of outcome and costs of OLT were a Child Pugh score >/=11 points or a MELD score >/=20 points. Patients in these strata showed a significant increase in LOS in the hospital (from a mean of 12 to 22 days) and intensive care stay (from a mean of 4 to 14 days) post-OLT when compared with patients with a lower CTP or MELD score (P <.05). There was also a trend toward higher hospital charges (P =.06). Organ allocation by MELD score will probably adversely affect the LOS and hospital charges of patients being transplanted due to ESLD.

Adult↗

Phosphate ions in root-tip dividing cells: a combined trapping and squash method with implications for nuclear transcription.

We examined the pattern of inorganic orthophosphate (PPi) ion distribution in dividing cells of Zea mays root-tips. Unfixed and paraformaldehyde- or glutaraldehyde-vapor fixed tissues were immersed in lead acetate, glutaraldehyde, and cacodylate buffer to capture PPi as insoluble orthophosphate lead hydroxyapatite. Excess lead ions were removed with sodium citrate, then permeabilized in ammonia. Precipitates were stained with potassium sulfide, washed with distilled water and squashed in a drop of glycerin. The accumulation of PPi ions was cyclic in the cytoplasm during mitosis and they surrounded all chromosomes during metaphase and anaphase. Partition between dividing cells started with a high concentration of PPi ions at sites where plasma membrane and cell walls formed. Small daughter cells and those in G1 phase had PPi concentrated in the nucleolus, with lower levels elsewhere in the nucleus. Later in the cell cycle, there were greater amounts of PPi ions associated with condensed chromatin in larger nuclei. In Xenopus laevis oocytes, PPi was concentrated in the nucleus, mainly in the active central core of multiple nucleoli. These results and others indicate that compartmentalization of PPi occurs in the intact cell and correlates with the rate of transcription in distinct functional domains within the nucleus.

Animals↗