Publications by authors named "Jr Pena"

Context.—: Ankylosing spondylitis (AS) is an autoimmune disorder with a strong genetic risk, especially with HLA-B27. Clinical testing for HLA-B27 has been used to help diagnose patients with signs and symptoms of AS.

View Article and Find Full Text PDF

In the heart, alternative splicing of the gene produces two isoforms: IGF-IEa and IGF-IEc, (Mechano-growth factor, MGF). The sequence divergence between their E-domain regions suggests differential isoform function. To define the biological actions of MGF's E-domain, we performed analysis of the unique C-terminal sequence and identified a phosphorylation consensus site residing within a putative 14-3-3 binding motif.

View Article and Find Full Text PDF

Context.—: In human leukocyte antigen (HLA)-mediated alloimmune platelet refractoriness, HLA-incompatible platelets may produce adequate posttransfusion corrected count increment ("permissive transfusion") and increase the donor pool.

Objective.

View Article and Find Full Text PDF

Objectives: No validated screening methods identify patients at risk for human leukocyte antigen (HLA) alloimmune-mediated platelet refractoriness (alloPR). We determined if bead-based HLA antibody tests could predict risk of developing HLA alloPR.

Methods: Hematopoietic progenitor cell transplant patients screened for HLA antibodies without prior refractoriness were identified.

View Article and Find Full Text PDF

Background And Objectives: Recent evidence suggests that HLA epitope-mismatching at HLA-DQ loci is associated with the development of anti-DQ donor-specific antibodies and adverse graft outcomes. However, the clinical significance of broad antigen HLA-DQ mismatching for graft outcomes is not well examined.

Design, Setting, Participants, & Measurements: Using the United Network Organ Sharing/the Organ Procurement and Transplantation Network (UNOS/OPTN) data, patients with primary kidney transplants performed between 2005 and 2014 were included.

View Article and Find Full Text PDF

Background: Platelet (PLT) refractoriness presents a challenging problem for transfusion support, especially in the perioperative setting, where there is urgency for human leukocyte antigen (HLA)-compatible units, yet identification and provision of compatible PLT concentrates requires time.

Case Report: A 22-year-old G3P1 woman with thrombocytopenia due to aplastic anemia, likely autoimmune, presented in her third trimester for peripartum care and newly diagnosed HLA alloimmune PLT refractoriness. Despite early planning, the patient developed bleeding requiring urgent delivery.

View Article and Find Full Text PDF

Hospital readmissions are common and expensive, and there is little information on the problem in Colombia. The objective was to determine the frequency of 30-day all-cause hospital readmissions and associated factors. This was a retrospective analytical cohort study of 64,969 hospitalizations from January 2008 to January 2009 in 47 Colombian cities.

View Article and Find Full Text PDF

Background: Until recently, liver transplantation (Ltx) was the only available treatment for hereditary transthyretin (TTR) amyloidosis; today, however, several pharmacotherapies are tested. Herein, we present survival data from the largest available database on transplanted hereditary TTR patients to serve as a base for comparison.

Methods: Liver transplantation was evaluated in a 20-year retrospective analysis of the Familial Amyloidosis Polyneuropathy World Transplant Registry.

View Article and Find Full Text PDF

The effects of storage time and temperature on blood alcohol concentration were evaluated in this two-part study involving 34 ethanol-negative and 21 ethanol-positive volunteers. Multiple 10-mL Vacutainer(®) blood tubes containing 100 mg of sodium fluoride and 20 mg of potassium oxalate were collected from living persons and subjected to various storage conditions. The time from collection to analysis ranged from 0 to 60 days and storage temperatures ranged from 3 to 20°C.

View Article and Find Full Text PDF

The Insulin like growth factor-I isoform mechano-growth factor (MGF), is expressed in the heart following myocardial infarction and encodes a unique E-domain region. To examine E-domain function, we delivered a synthetic peptide corresponding to the unique E-domain region of the human MGF (IGF-1Ec) via peptide eluting polymeric microstructures to the heart. The microstructures were made of poly (ethylene glycol) dimethacrylate hydrogel and bioengineered to be the same size as an adult cardiac myocyte (100 × 15 × 15 μm) and with a stiffness of 20 kPa.

View Article and Find Full Text PDF

Insulin like growth factor-I (IGF-1) isoforms differ structurally in their E-domain regions and their temporal expression profile in response to injury. We and others have reported that Mechano-growth factor (MGF), which is equivalent to human IGF-1c and rodent IGF-1Eb isoforms, is expressed acutely following myocardial infarction (MI) in the mouse heart. To examine the function of the E-domain region, we have used a stabilized synthetic peptide analog corresponding to the unique 24 amino acid region E-domain of MGF.

View Article and Find Full Text PDF

Anti-human leukocyte antigens (HLA) antibodies can adversely impact the care of hematology patients. In particular, HLA antibody testing provides important information for optimal stem cell and platelet donor selection in the management of stem cell recipients and platelet refractory patients. Current testing methods for HLA antibodies are briefly reviewed, with particular emphasis on laboratory and clinical issues associated with solid-phase multiplex assays.

View Article and Find Full Text PDF

Alloimmune platelet refractoriness (alloPR) among actively bleeding surgical patients with thrombocytopenia represents a life-threatening problem. Here we present three cases in which surgical bleeding was complicated by life-threatening thrombocytopenia and alloPR. We demonstrate that the human leukocyte antigens (HLA) antibodies associated with alloPR are broadly reactive and in high concentration, are not removed by hemodilution, and are not absorbed by transfusion of multiple doses of platelet concentrates.

View Article and Find Full Text PDF

The scope of activity of the Blood Transfusion Service (BTS) makes it unique among the clinical laboratories. The combination of therapeutic and diagnostic roles necessitates a multi-faceted approach to utilization management in the BTS. We present our experience in utilization management in large academic medical center.

View Article and Find Full Text PDF
Article Synopsis
  • Familial hypertrophic cardiomyopathy (FHC) is characterized by increased heart muscle thickness, fibrosis, and abnormal heart function, and the study utilizes two mouse models to investigate this condition.
  • One model carries a mutation that causes severe cardiac hypertrophy (Tm180), while the other is a gene knockout that leads to increased heart contractility without issues (PLN KO).
  • The study found that when crossing these models (PLN KO/Tm180), the offspring showed improved heart function and morphology, highlighting 1,187 genes that change expression during cardiac remodeling, with some genes contributing to reversing the hypertrophic phenotype.
View Article and Find Full Text PDF

The complement-dependent cytotoxic crossmatch is an informative test that detects alloantibodies in pre- and post-transplant patients, which may dictate clinical management of transplant patients. While challenging to perform, the cytotoxic crossmatch represents the only assay that provides direct evidence for the presence of potentially pathologic (i.e.

View Article and Find Full Text PDF

We have recently shown that a temporary increase in sarcoplasmic reticulum (SR) cycling via adenovirus-mediated overexpression of sarcoplasmic reticulum ATPase (SERCA2) transiently improves relaxation and delays hypertrophic remodeling in a familial hypertrophic cardiomyopathy (FHC) caused by a mutation in the thin filament protein, tropomyosin (i.e., α-TmE180G or Tm180).

View Article and Find Full Text PDF

Familial hypertrophic cardiomyopathy (FHC) is an autosomal dominant genetic disorder linked to numerous mutations in the sarcomeric proteins. The clinical presentation of FHC is highly variable, but it is a major cause of sudden cardiac death in young adults with no specific treatments. We tested the hypothesis that early intervention in Ca(2+) regulation may prevent pathological hypertrophy and improve cardiac function in a FHC displaying increased myofilament sensitivity to Ca(2+) and diastolic dysfunction.

View Article and Find Full Text PDF

We investigated the role of inducible NOS (iNOS) on cardiac function during the development of left ventricular hypertrophy. Hypertrophy was induced by pressure-overload via short-term (2.5 months) or long-term (6.

View Article and Find Full Text PDF

We have tested the hypothesis that alterations in length dependent activation (LDA) of cardiac myofilaments represent an important regulatory mechanism affecting the Frank-Starling mechanism as determined by the slope (E(es)) of the relation between left ventricular (LV) volume and end-systolic pressure. We employed a transgenic (TG) mouse model in which the cardiac isoform of TnI (cTnI) has been completely replaced with slow skeletal TnI (ssTnI), the embryonic/neonatal isoform in the heart. Compared to non-transgenic (NTG) controls, myofilaments from TG-ssTnI hearts demonstrate an increase in Ca(2+) sensitivity and a substantially blunted LDA that is unaffected by PKA-dependent phosphorylation.

View Article and Find Full Text PDF

Compared to sham-operated controls, myofilaments from hearts of ovariectomized (OVX) rats demonstrate an increase in Ca2+ sensitivity with no change in maximum tension (Wattanapermpool J and Reiser PJ. Am J Physiol 277: H467-H473, 1999). To test the significance of this modification in intact cells, we compared intracellular Ca2+ transients and shortening of ventricular myocytes isolated from sham and 10-wk OVX rats.

View Article and Find Full Text PDF
Article Synopsis
  • The study explores the influence of myosin regulatory light chain (RLC) phosphorylation on cardiac function, specifically the force-frequency and pressure-frequency relationships in mouse hearts.
  • Results indicate that while RLC phosphorylation levels did rise slightly with increased stimulation frequency, it did not significantly affect force or pressure responses, especially in transgenic mice with nonphosphorylatable RLC.
  • Additionally, the study found that nonphosphorylatable RLC led to decreased contractility and systolic pressure in the heart, while not altering other calcium transient parameters or muscle shortening behavior.
View Article and Find Full Text PDF

Compared with the adult, neonatal heart muscle is less sensitive to deactivation by acidic pH. We hypothesized that expression of slow skeletal troponin I (ssTnI), the embryonic isoform, in adult heart would help maintain left ventricular (LV) systolic function during respiratory hypercapnia. We assessed LV function by transthoracic 2D-targeted M-mode and pulsed Doppler echocardiography in transgenic (TG) mice in which cardiac TnI was replaced with ssTnI and in nontransgenic (NTG) littermates.

View Article and Find Full Text PDF

We evaluated the effect of the inhalant anesthetic isoflurane and the injectable combination of anesthetics ketamine/inactin on cardiac function by measuring left ventricular (LV) pressure in situ during control conditions and during beta-adrenergic stimulation with isoproterenol (ISO). The control heart rate (HR) and the maximal rate of contraction were significantly higher in the isoflurane group, but there was no difference in the rate of relaxation. During the ISO (0.

View Article and Find Full Text PDF

Objective: The present study was designed to address the question of the contribution of cardiac troponin I (cTnI) phosphorylation to the enhanced rate of relaxation during beta-adrenergic stimulation in hearts in situ.

Methods: In situ hemodynamic measurements were performed in mouse hearts that (1) express normal level of phospholamban (PLB) and either express cTnI (PLB/cTnI) or the slow skeletal isoform of TnI (PLB/ssTnI) that cannot be phosphorylated by protein kinase A (PKA) or (2) do not express PLB and either express cTnI (PLBKO/cTnI) or ssTnI (PLBKO/ssTnI).

Results: In the basal state, there was no difference in heart rate (HR), developed pressure (DP), left ventricular end-diastolic pressure (LVEDP) or rate of contraction (+dP/dt) between PLB/cTnI and PLB/ssTnI groups.

View Article and Find Full Text PDF