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Background and Objectives: Inorganic polyphosphate (polyP), a ubiquitous phosphate polymer with ATP-like bonds, has recently been related to a variety of functions including blood coagulation and cell proliferation. We investigated the effects of polyP in the biology of human plasma cells (PC), responsible for the production and maintenance of antibodies in response to antigens., Design and Methods: The U266 myeloma cell line was used to study whether polyP affects immunoglobulin (Ig) secretion and survival. Different human cell lines were used to test the specificity of polyP on viability. We analyzed Ig secretion of PC from bone marrow and peripheral blood after polyP addition. A conventional tetanus toxoid booster immunization was used to increase the proportion of PC in order to examine the ex vivo effects of polyP. We also tested the effects of polyP on primary myeloma cells. Ig secretion and apoptosis were determined by ELISA and FACS respectively., Results: Addition of polyP to human PC produced an unexpected inhibition of Ig secretion and stimulation of apoptosis. PolyP generated apoptosis specifically in PC, myeloma (malignant PC) cell lines, primary myeloma cells, and B lymphoid cell lines. Normal B cells, T cells, total blood mononuclear cells, and non-lymphoid cell lines were not affected by polyP. In the U266 myeloma cell line, polyP induced externalization of phosphatidylserine, activation of caspase-3, and arrest of the cell cycle. The protective effects of interleukin-6 did not overcome the polyP-induced apoptosis Interpretation and, Conclusions: Taken together, our results suggest for the first time the relevance of the use of polyP to the humoral immune response and open prospects for polyP as a novel therapy for myeloma.

Background: Respiratory syncytial virus (RSV) is an important cause of respiratory tract disease in infants and young children. Immunoprophylaxis is available for high-risk infants. This study reviews infants with bronchiolitis at three primary care hospitals to describe the epidemiology of RSV infection in Puerto Rico., Methods: We analyzed data from 2 hospitals by obtaining the number of infants diagnosed with bronchiolitis and estimating the percentage of cases due to RSV. A third hospital included patients with confirmed RSV infection., Results: There were 4,557 patients in the study. RSV infection occurred throughout the year. Data shows a progressive decrease in RSV-positive infections., Conclusions: Data confirms year-round incidence of RSV in Puerto Rico. A standardized surveillance system in Puerto Rico is imperative to determine RSV epidemiology. The decrease in positive RSV infections may be due to the introduction of immunoprophylaxis to high-risk patients.

Jarcho-Levin syndrome, also known as spondylothoracic dysplasia and characterized by short trunk dwarfism, "crab-like" rib cage, with ribs and vertebral defects; it is not uncommon in Puerto Ricans. Many patients die in early infancy due to respiratory compromise associated to lung restriction and the reported cases emphasize mostly the skeletal malformations associated to the syndrome. We report the autopsy findings in a newborn with isolated Jarcho-Levin syndrome emphasizing pulmonary pathology. He was a pre-term male who died of respiratory failure at three hours old and, autopsy findings confirmed the clinical diagnosis. Internal examination showed hypoplastic lungs with normal lobation. The histological structure appeared normal and relatively mature; the diaphragm showed eventration and unilateral absence of musculature. This case shows the worst spectum of the Jarcho-Levin syndrome: pulmonary hypoplasia not compatible with extrauterine life. Since thoracic restriction is present during the fetal period, the degree of pulmonary hypoplasia probably defines survival beyond the neonatal period.

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory illness in children. Prevention of this infection is available with the use of intravenous immunoglobulin or an intramuscular humanized monoclonal antibody (palivizumab). Palivizumab has been available in Puerto Rico since 1999. The objective of this study was to follow-up infants who received RSV prophylaxis with palivizumab in Puerto Rico to assess its efficacy and safety. A total of 230 infants who received RSV prophylaxis during the 2000-2001 and 2001-2002 seasons were followed-up. Adverse events from injections were minimal including erythema (2%), fever (5%), pain (4%), and rash (2%). In none of the patients prophylaxis was discontinued due to side effects. Forty-four infants (19%) had at least one respiratory hospitalization throughout the season, with RSV confirmed in seven (3%). Most hospitalizations occurred in the month of August when infants had received only one dose of palivizumab and on December, a peak month for RSV infections. Five infants (2.2%) required admission to an intensive care unit. In none of them, RSV was confirmed. This study confirms that monthly intramuscular administration of palivizumab is effective in preventing serious RSV infections in high risk infants.

Background: Cesarean section is a common delivery route for breech fetuses < 1000 gm to prevent trauma. However, abdominal and vaginal delivery maneuvers are similar. Cesarean section avoids the risk of head entrapment but long bone trauma can still occur., Cases: We identified three neonates with femoral fractures during a one year period. All mothers were in active labor. All were premature newborns less than 32 weeks gestation, in breech presentation and delivered by a low vertical cesarean section. Review of all cesarean sections done due to mal presentation (n = 26) during that time showed 11 classic and 15 lower segment vertical incisions (both vertical and transverse)., Conclusions: The interest to reduce maternal morbidity may prompt physicians to perform a low segment vertical incision for delivery of a preterm breech. This decision may increase the chances of trauma by providing less area for the required obstetric maneuvers.

Plasma cells (PCs) are the final B-cell differentiation stage. Recent evidence reveals relevant functional differences within the PC compartment. In rodents, early PCs formed in secondary lymphoid tissues show enhanced apoptosis and short life span, whereas PCs present in a final destination organ, such as the bone marrow (BM), have reached a stable prolonged survival state. BM PCs arrive at this organ as a circulating precursor whose cellular nature remains uncertain. An initial aim of this study was to characterize this circulating cell. We hypothesized that antibody-secreting cells detectable in the human blood after immunization might be a candidate precursor. These cells were obtained from the blood of volunteers immunized 6 days earlier with tetanus toxoid (tet), and they were unambiguously identified as PCs, as demonstrated by their expression of the CD38(h) phenotype, by morphology, by immunoglobulin (Ig) intracytoplasmic staining, and by IgG-tet-secreting capacity in vitro. In addition, by using the common CD38(h) feature, human PCs from tonsil (as a possible source of early PCs), from blood from tet-immunized donors (as the putative precursors of BM PCs), and from BM (as a deposit organ) have been purified and their phenotypes compared. The results show that a variety of differentiation molecules, proteins involved in the control of apoptosis, the B-cell transcription factors, positive regulatory domain I-binding factor 1/B lymphocyte-induced maturation protein 1 and B cell-specific activating protein and, at least partially, the chemokine receptor CXCR4 were expressed by human PCs following a gradient of increasing maturity in the direction: tonsil-->blood-->BM. However, PCs from these different organs showed a local pattern of adhesion molecule expression. These observations are discussed in light of the complex physiology of the human PC compartment.

Homozygosity for a common polymorphism in the 5,10 methylenetetrahydrofolate reductase (MTHFR) gene (C677T) has been associated to an increased risk of neural tube defects as well as derangements in folate, homocysteine, and hematological parameters. This study analyzed the relationship between folate levels, the erythrocyte volume, and the presence of homozygosity for the C677T polymorphism in a group of 126 Puerto Rican healthy women of childbearing age. Blood samples were analyzed for erythrocyte mean corpuscular volume (MCV), mean erythrocyte hemoglobin content (MCH), folate, and RBC folate. Homozygosity for the C677T mutation was determined by PCR. Thirty-two percent (32%) of women used a folic acid supplement during the three months prior to sampling. Mean folate and RBC folate levels were within the normal range. Individuals homozygous for the MTHFR C677T polymorphism had no elevation of MCV (p = 0.70) or MCH (p = 0.68). Women in the lower quartile of folate levels did not show differences in their MCV or MCH. In this sample of Puerto Rican women, homozygosity for the C677T MTHFR polymorphism was not associated to elevations of MCV or MCH even in the presence of lower folate levels.