Biomedical subjects

C Richard

Publications and source records attributed to C Richard.

At least 109 records · Page 6Linked to original sources

PubMed1998

Pathogenesis of polycythemia vera.

BACKGROUND AND OBJECTIVE: Polycythemia vera (PV) is an acquired clonal myeloproliferative disorder characterized by increased production of mature red cells. We still lack a molecular target responsible for this disorder; however, recent investigations have focused on a number of molecules involved in signal transduction pathways mediated by erythropoietin (Epo) and other growth factors. Here we review the implication of these molecules in the pathogenesis of PV. INFORMATION SOURCES: The material reviewed in this work includes articles published in journals covered by Medline. We also include data obtained in our laboratory regarding to the significance of apoptosis inhibitory proteins in erythroid development. STATE OF THE ART AND PERSPECTIVES: Overproduction of erythroid cells in PV is particular in that it occurs in the absence of a recognizable physiologic stimulus, since circulating serum levels of Epo are normal or lower than normal. Genetic analysis as well as in vitro studies, have established an essential role for Epo in the survival and maturation of committed erythroid progenitors. Epo initiates its cellular response by binding to the Epo receptor (EpoR) expressed on the surface of immature erythroblasts. Following ligand binding, EpoR is known to activate a cytoplasmic protein tyrosine kinase, Jak2 which triggers a signal transduction cascade that leads to the development of early erythroid progenitors into mature erythroblast cells. Although the mechanism underlying the increased erythroid production in PV is not well understood, a number of causes have recently came for which may provide insights not only for the pathogenesis of PV but also for a fundamental biological process: the mechanism whereby a multipotential stem cell gives rise to a particular cell lineage.

Animals↗

PubMed1998

Quality of life in young adults having received a BMT during childhood: a GETMON study. Grupo Español de Trasplante de Médula Osea en el Niño.

A quality-of-life questionnaire study was administered in a group of 98 disease-free survivors more than 3 years after BMT. All participants were over the age of 17 years at the time of the survey. The transplants were performed between 1981 and 1993 in eight Spanish hospitals. Eighty-three percent of patients had undergone BMT for neoplastic disease. Seventy-three per cent received an allogeneic bone marrow transplantation. A modified version of a questionnaire applied in Stanford Hospital to evaluate quality of life in adults after BMT was used. A single investigator was responsible for interviewing all subjects by telephone. We compare these results with the same questionnaire applied in a control group of 58 healthy subjects of similar age. The most significant results were: BMT patients valued their quality of life more highly than the control group. The mean score for global quality of life was 8.19+/-0.17 in BMT group as compared to 7.54+/-0.13 in control group (P=0.0013). Studies were cited as the major concern in both groups: 24% in BMT group and in 69% in control group (C.I. 95%=0.59 to 0.30). The patients in the BMT group considered they had fewer problems in comparison with the control group regarding interpersonal relationships with family members and friends, sleep, depression and leisure possibilities. However, they considered they had more problems concerning their physical appearance, studies and work possibilities than their peers. Considerations regarding weight, height, sexual functioning, anxiety, tendency to suffer illness and problems with insurance were similar in both groups.

Adolescent↗

PubMed1998

[Prognostic factors in low-grade lymphoma].

PURPOSE: Prognostic factors in low grade non-Hodgkin's lymphoma (LGL) are not well established. The aim of this study is to investigate prognostic factors on LGL treated in our institution during the last decade. PATIENTS AND METHODS: The study was carried out on 70 cases of newly diagnosed LGL, most treated with CVP or clorambucil and prednisone. The median follow-up was 37 months (1-132). Variables reported as prognostic factors in previous series were subjected to bivariate and multivariate analysis. RESULTS: Relevant clinical features were: Ann Arbor III-IV stage 74%, ECOG > or = 2-17%, bone marrow involvement 60% and large tumor burden according to MD Anderson criteria 21%. Complete response (CR) was achieved in 50% and partial response in 29%. In bivariate analysis factors related with poor CR were B symptoms, large tumor burden, high LDH and more than one extranodal site involvement. Logistic regression showed that large tumor burden (p = 0.02; OR = 0.07) and B symptoms (p = 0.07; OR = 0.14) were the best prognostic factors of poor CR. Five year global survival (GS) was 55%, with a median of 76 months. In univariate analysis factors related with GS were ECOG > or = 2, B symptoms, bulky, large tumor burden, retroperitoneo involvement and absence of CR. In multivariate analysis the only factor related with poor GS was large tumor burden (p < 0.00001; RR = 5.93). When therapeutic response was included in the model, absence of CR (p = 0.008; RR = 3.40) and large tumour burden (p = 0.005; RR = 3.86) were the factors selected. CONCLUSIONS: In LGL tumor burden was the most important prognostic variable. Tumor response showed less importance than in high grade lymphomas.

Adult↗

PubMed1998

Treatment of Ph1-positive chronic myelogenous leukemia in children: comparison between allogeneic bone marrow transplantation and conventional chemotherapy. Spanish Working Party for BMT in Children (GETMON).

BACKGROUND AND OBJECTIVE: To compare the estimated survival and disease-free survival between children with Ph1-positive chronic myeloid leukemia treated with allogeneic bone marrow transplantation or conventional chemotherapy. DESIGN AND METHODS: In this retrospective study we compared the results obtained in a group of 14 children who received allogeneic bone marrow transplantation (BMT) between 1983 and 1993, and another group of 27 children treated with busulfan, hydroxyurea or alpha-interferon during the same time period. Patients were transplanted at a median of 7 months from diagnosis and all except one were in their first chronic phase. Conditioning consisted in total body irradiation and cyclophosphamide in 12 cases, and busulfan was added in two. RESULTS: Of the 14 patients treated with BMT, two died of transplant-related complications and two relapsed 18 and 48 months after the BMT. Ten children remain alive and disease free at a median follow up of 60 months. The probability of DFS at 5 years is 70%. Of the 27 patients treated with chemotherapy, 22 have died at a median of 36 months from diagnosis. The probability of survival at 5 years is 5% versus 83% for the BMT group (p = 0.001). INTERPRETATION AND CONCLUSIONS: Allogeneic BMT is a safe and very effective treatment for Ph-positive CML in children. Patients who have an HLA-identical sibling donor must receive a transplant as soon as possible after being diagnosed.

Adolescent↗

PubMed1997

Interferon induces up-regulation of Spi-1/PU.1 in human leukemia K562 cells.

The human K562 cell line is derived from a chronic myelogenous leukemia in blastic crisis. Treatment of K562 cells with interferons alpha, beta or gamma resulted in inhibition of cell proliferation. Spi-1/PU.1 is a transcription factor of the Ets family which is required for normal hematopoyesis. We have found that spi-1 mRNA and protein as well as Spi-1-DNA binding activity increase after exposure of K562 cells to interferons. The increase in spi-1 expression ranged from 4- to 8-fold with the different interferons. K562 cells can be differentiated in vitro towards erythroid cells or monocyte-macrophage cells. Interestingly, the regulation of spi-1 by interferon-alpha depended on the differentiated phenotype of K562 cells: interferon-alpha failed to induce spi-1 in erythroid differentiated cells, whereas it induced spi-1 in monocyte-macrophage differentiated cells. The results suggest a role for Spi-1 in the cytostatic response to interferons.

Animals↗

PubMed1997

The expression of Bcl-x is downregulated during differentiation of human hematopoietic progenitor cells along the granulocyte but not the monocyte/macrophage lineage.

Expression of the apoptosis inhibitory protein Bcl-x was studied in CD34+ hematopoietic precursor cells and in the promyelocytic leukemia cell line HL-60. The enriched population of CD34+ cells (more than 95%) was cultured in the presence of stem cell factor, interleukin-3 (IL-3), IL-6, and either granulocyte colony-stimulating factor or macrophage colony-stimulating factor to achieve granulocyte or monocyte/macrophage differentiation, respectively. The expression of Bcl-x increased in the early stages of both differentiation pathways. However, by day 21 of culture mature granulocytes were Bcl-x-negative, whereas monocytes/macrophages either maintained or increased the expression of Bcl-x. The pattern of Bcl-x expression in the differentiated CD34+ cells was similar to that observed in HL-60 cells differentiated along the granulocyte lineage (induced by incubation with retinoic acid), or along the monocyte/macrophage lineage (induced by incubation with phorbol diester). The bcl-x transcript predominant in HL-60 and CD34+ cells differentiated into monocytes/macrophages was bcl-xL. Although little is yet known regarding the functional significance of Bcl-x within the granulomonocytic compartment, marked changes in the pattern of its expression, as observed during granulomonocytic differentiation of HL-60 and CD34+ cells, are likely to alter the life span of mature granulocytes and monocytes/macrophages.

Antigens, CD↗

PubMed1997

Max and inhibitory c-Myc mutants induce erythroid differentiation and resistance to apoptosis in human myeloid leukemia cells.

We have used the human leukemia cell line K562 as a model to study the role of c-myc in differentiation and apoptosis. We have generated stable transfectants of K562 constitutively expressing two c-Myc inhibitory mutants: D106-143, that carries a deletion in the transactivation domain of the protein, and In373, that carries an insertion in the DNA-interacting region. We show here that In373 is able to compete with c-Myc for Max binding and to inhibit the transformation activity of c-Myc. K562 cells can differentiate towards erythroid or myelomonocytic lineages. K562 transfected with c-myc mutants showed a higher expression of erythroid differentiation markers, without any detectable effects in the myelomonocytic differentiation. We also transfected K562 cells with a zinc-inducible max gene. Ectopic Max overexpression resulted in an increased erythroid differentiation, thus reproducing the effects of c-myc inhibitory mutants. We also studied the role of c-myc mutants and max in apoptosis of K562 induced by okadaic acid, a protein phosphatases inhibitor. The expression of D106-143 and In373 c-myc mutants and the overexpression of max reduced the apoptosis mediated by okadaic acid. The common biochemical activity of D106-143 and In373 is to bind Max and hence to titrate out c-Myc to form non-functional Myc/Max dimers. Similarly, Max overexpression would decrease the relative levels of c-Myc/Max with respect to Max/Max. The results support a model where a threshold of functional c-Myc/Max is required to maintain K562 cells in an undifferentiated state and to undergo drug-mediated apoptosis.

Apoptosis↗

PubMed1997

Decreased neurofilament gene expression is an index of selective axonal hypotrophy in ageing.

Axonal atrophy may reflect earlier and more reversible events in neurodegeneration and ageing than somatic atrophy. Innervation density by sympathetic fibres from the rat superior cervical ganglion (SCG) to the middle cerebral artery (MCA) decreases dramatically in old age, while that to the iris is largely unchanged. In situ hybridization was used in conjunction with retrograde tracers to examine the role of the neuronal cytoskeleton in this selective axonal vulnerability. Using a riboprobe complementary to neurofilament light chain (NF-L) mRNA, there was a 22-25% decrease in the mean grain density in aged neurones when all neurones were examined. A small subset of these neurones was shown to project to the MCA and another to the iris. In young SCG, both subpopulations expressed intermediate grain densities for NF-L mRNA. In MCA-projecting neurones, there was a 40% decline in grain density with ageing (p < 0.05), with no change in iris-projecting neurones. Our results demonstrate that major decreases in NF-L expression may represent cellular markers of selective axonal hypotrophy by aged neurones.

Aging↗

PubMed1997

Maternal proximity and infant CO2 environment during bedsharing and possible implications for SIDS research.

Sudden infant death syndrome (SIDS) is the leading cause of human infant mortality after the neonatal period in Western countries. Recently, child care practices have been shown to be important in determining infant vulnerability to SIDS. However, very little is known about the impact of parent-infant cosleeping on infant sleep physiology and behavior and SIDS risk. This reflects the failure of Western societal research paradigms to appreciate the human infant's evolutionary history of cosleeping, the recency of the emergence of solitary infant sleeping as a practice and the fact that parent-infant cosleeping is still the preferred sleeping arrangement for the majority of contemporary societies. Incorporating current hypotheses on the mechanisms of SIDS, we have hypothesized that the comparatively sensory-rich cosleeping environment might be protective against SIDS in some contexts. As a first step to characterize cosleeping environments, this investigation is aimed at assessing, in routinely bedsharing mothers and infants, their relative sleeping positions and the potential for sleeping in close face-to face proximity and for infant exposure to increased environmental CO2 produced by maternal respiration. The latter is important in that breathing elevated levels of CO2 can have diverse effects, ranging from respiratory stimulation at low levels to suffocation at very high levels. Two related laboratory studies were performed. In the first, all-night videotapes of 12 healthy, routinely bedsharing mother-infant pairs were analyzed for sleeping positions and time spent in face-to-face orientation and distances separating their faces. Infants were 11-15 wk old. Mothers predominantly positioned themselves on their sides facing their infants, with the infants placed either supine or on their sides. Mothers and infants slept oriented face-to-face for 64 +/- 27% (S.D.) of non-movement time, with distance less than 20 cm commonly separating their faces. In the second study, concentrations of CO2 in air were measured in six young women at distances of up to 21 cm from their nares. Peak expiratory CO2 concentrations remained above 1.0% at distances up to 9 cm and above 0.5% at 18 cm. Both baseline and peak CO2 levels were further increased at all distances when measured within a partial air pocket created to simulate a bedding environment sometimes seen during bedsharing. We conclude that during bedsharing there is potential for 1) a high degree of face-to-face orientation and close proximity and consequently 2) increased environmental CO2, as a result of maternal respiration, to non-lethal levels that might stimulate infant respiration. The close proximity would also maximize the sensory impact of the mother on the infant through other modalities. We also suggest that bedsharing may minimize prone infant positioning, a known risk factor for SIDS.

Adolescent↗

PubMed1997

Proximal tubular injury in Chinese herbs nephropathy: monitoring by neutral endopeptidase enzymuria.

Neutral endopeptidase (NEP) is a 94 kDa ectoenzyme of the proximal tubule brush border, physiologically released into the urine with apical membrane fragments. As proximal tubular atrophy was a histological hallmark of Chinese herbs nephropathy (CHN), this study firstly determined renal excretion of NEP in healthy control subjects (N = 31), in patients with CHN (N = 26) and in women having consumed Chinese herbs and whose renal function was normal but running the risk of developing CHN (N = 27). Another patient group consisted of female patients with glomerular diseases (N = 12). At the same time, measurements of urinary microproteins (Clara cell protein, retinol binding protein, beta 2-microglobulin and alpha 1-microglobulin) were performed, as indicators of tubular dysfunction. Cell damage was estimated by the excretion of N-acetyl-beta-D-glucosaminidase (NAG). In the control group, the physiological NEP enzymuria was 43.1 micrograms/24 hr (geometric mean). In CHN patients, levels of urinary NEP were significantly decreased in those with moderate renal failure (26.7 micrograms/24 hr; N = 21; P < 0.05) and almost abolished in end-stage renal failure patients (4.35 micrograms/24 hr; N = 5; P < 0.05). In patients at risk as well as in patients with glomerular diseases, urinary NEP levels were not statistically different from those observed in control subjects (40.68 micrograms/24 hr and 48.5 micrograms/24 hr, respectively). Several degrees of tubular dysfunction and injury were noted in patients groups, as attested by increased urinary microproteins and NAG excretions. Considering the data from control and CHN patients, NEP enzymuria positively correlated with individual creatinine clearance values (r = 0.76; P = 0.0001) and negatively correlated with urinary microproteins levels (r = -0.55; P = 0.00001). Finally, NEP was regularly quantitated in the urine of 6 CHN patients for a period ranging from six months to two years and in 19 patients at risk during two years, respectively. In the first group, renal function progressively deteriorated in 3 patients, leading them to renal replacement therapy after 38 to 115 weeks. Stable parameters were observed in the remaining 3 patients. A direct correlation between creatinine clearance and NEP excretion was found longitudinally in each case. In the second group, no significant change of urinary NEP levels was observed (45.9 micrograms/24 hr), in parallel with stable renal function. Taken together, these results indicate that, in CHN patients, NEP enzymuria provides a rapid and noninvasive determination of the degree of structural impairment affecting the proximal tubular population and further reflecting the severity of the renal disease. The interest of this urinary marker in monitoring the progression of other tubulointerstitial diseases remains to be assessed.

Adult↗

PubMed1997

Cloning, expression and chromosomal mapping of human lysosomal sialidase and characterization of mutations in sialidosis.

Sialidase (neuraminidase, EC 3.2.1.18) catalyses the hydrolysis of terminal sialic acid residues of glyconjugates. Sialidase has been well studied in viruses and bacteria where it destroys the sialic acid-containing receptors at the surface of host cells, and mobilizes bacterial nutrients. In mammals, three types of sialidases, lysosomal, plasma membrane and cytosolic, have been described. For lysosomal sialidase in humans, the primary genetic deficiency results in an autosomal recessive disease, sialidosis, associated with tissue accumulation and urinary excretion of sialylated oligosaccharides and glycolipids. Sialidosis includes two main clinical variants: late-onset, sialidosis type I, characterized by bilateral macular cherry-red spots and myoclonus, and infantile-onset, sialidosis type II, characterized by skeletal dysplasia, mental retardation and hepatosplenomegaly. We report the identification of human lysosomal sialidase cDNA, its cloning, sequencing and expression. Examination of six sialidosis patients revealed three mutations, one frameshift insertion and two missense. We mapped the lysosomal sialidase gene to human chromosome 6 (6p21.3), which is consistent with the previous chromosomal assignment of this gene in proximity to the HLA locus.

Amino Acid Sequence↗

PubMed1997

Maternal sleep and arousals during bedsharing with infants.

Contrary to popular perception, studies show that parent-infant bedsharing is not uncommon in American society. A belief that bedsharing with infants negatively impacts the quality of adult sleep also appears wide-spread. This has not been substantiated, however, because the few studies that have measured the impact of bedsharing on adult sleep examined only bedsharing with another adult. In the present study, laboratory polysomnography was performed in 20 routinely bedsharing and 15 routinely solitary-sleeping, breastfeeding, Latino mother-infant pairs comparing the mothers' sleep when bedsharing to solitary-sleeping nights. Infants were 11-15 weeks old at the time. Irrespective of routine sleeping arrangement, mothers' total sleep time was not decreased on the bedsharing night compared to the solitary night. Across the two groups, percent Stage 3-4 sleep (of total sleep time) was significantly reduced on the bedsharing night but only by 3.9%, while Stage 1-2 sleep was increased 3.7%. Episodes of both Stages 3-4 and 1-2 were significantly shorter. The amount of rapid eye movement (REM) sleep was unaffected. Overall, arousal frequency was significantly increased by 3.6 hour-1. As the increase in arousal frequency was stage specific, it could account for the pattern of stage changes. Nocturnal wakefulness was not increased, however, because awakenings were of shorter duration. these effects of bedsharing did not habituate with routine bedsharing because they were not diminished in the routinely bedsharing mothers compared to the routinely solitary-sleeping mothers. We find that the impact of bedsharing on maternal sleep is modest and somewhat different from the reported impact of sleeping with another adult. From the infant's standpoint, the effects on maternal sleep are adaptive to the extent that opportunities to monitor the infant's status are enhanced. The mother's caregiver role is likely germane to differential effects on sleep of bedsharing with an infant versus another adult.

Adult↗

PubMed1997

Pharmacokinetic-pharmacodynamic model relating spiraprilat plasma concentrations to systemic and regional hemodynamic effects in congestive heart failure.

The aim of this study was to investigate the relations between the plasma concentrations of spiraprilat (the active metabolite of the angiotensin-converting enzyme inhibitor spirapril) and its effects on plasma converting enzyme activity (PCEA), pulmonary capillary wedge pressure (PCWP), and brachial blood flow (BBF), after a single oral administration of 6 mg of spirapril in eight patients with severe congestive heart failure (CHF). Concentrations and effects were determined before and repeatedly during 48 h after drug intake. A sigmoid model was fitted to individual observations. Maximal effects, concentrations inducing half-maximal effects, and Hill coefficients were -99 +/- 2%, 3.9 +/- 1.9 ng/ml, and 2.4 +/- 0.7 for PCEA inhibition, -15 +/- 8 mm Hg, 11.8 +/- 9.2 ng/ml, and 2.6 +/- 1.3 for PCWP decrease, and 36 +/- 19 ml/min, 13.8 +/- 7.6 ng/ml, and 3.3 +/- 1.0 for BBF increase. In severe CHF, although a 14 ng/ml plasma concentration of spiraprilat may induce a 95% inhibition of PCEA, a 30 ng/ml plasma concentration is mandatory to normalize PCWP and BBF. This concentration corresponds to the peak achieved after a 6-mg oral dose of spirapril.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1997

Deep infections caused by Scedosporium prolificans. A report on 16 cases in Spain and a review of the literature. Scedosporium Prolificans Spanish Study Group.

Scedosporium prolificans, a mold morphologically similar to Scedosporium apiospermum, may cause asymptomatic colonization or localized or disseminated infection following trauma, surgery, and immunosuppression. S. prolificans is normally resistant to available antifungal agents, and prognosis depends largely on the host's immune status, extent of infection, and feasibility of surgical debridement. We report on 16 patients with deep S. prolificans infections, focusing on predisposing factors, clinical characteristics, outcome, postmortem findings, and antifungal susceptibility testing to 6 antifungal agents. Between 1989 and 1994, 16 cases of deep infections by S. prolificans were documented in 6 clinical centers in Spain (15 adults and 1 child: male/female = 0.77). Fifteen patients had underlying hematologic malignancy (14 with neutropenia) and 1 had a prosthetic cardiac valve. Syndromes included disseminated infection in 14 patients (1 with prosthetic valve endocarditis) and fungal pneumonia and meningoencephalitis in 1 patient each. S. prolificans was isolated from 2 specimens in 14 patients and from 1 specimen in 2 patients (blood, n = 12; respiratory tract, n = 4; CNS, n = 4; and skin biopsy, n = 3). Antifungal susceptibility testing by a micromethod with RPMI-2% glucose medium was performed in 8 isolates, all of which were resistant to amphotericin B, flucytosine, ketoconazole, fluconazole, itraconazole, and miconazole. All patients received antifungal therapy (amphotericin B, n = 9; amphotericin B+ flucytosine, n = 1; amphotericin B+ itraconazole, n = 2; liposomal amphotericin B+ itraconazole, n = 1; amphotericin B+ fluconazole, n = 1 and 2 underwent surgical procedures. Two patients survived coinciding with hematologic recovery and 14 (87.5%) patients died in a median time of 4 days after the first positive culture (range, 0-60 d). Necropsy was performed in 10 patients, and disseminated infection was found in 9. In conclusion, S. prolificans is an emerging multiresistant fungal pathogen that may cause asymptomatic colonization, localized infection related to trauma or surgery, and rapidly fatal disseminated infection in immunocompromised hosts, particularly those with neutropenia. This mycosis underscores the urgent need for new antifungal agents.

Adolescent↗

PubMed1997

Inverse ratio ventilation (I/E = 2/1) in acute respiratory distress syndrome: a six-hour controlled study.

To assess the cardiorespiratory effects of a prolonged application of inverse ratio ventilation (IRV), we compared IRV (I/E = 2) with conventional ventilation (CV) (I/E = 0.5), applied for 6 h each in a randomized order, with constant tidal volume (VT) and total positive end-expiratory pressure (PEEP(tot)) in eight patients with acute respiratory distress syndrome (ARDS). After 1 h, IRV resulted in a lower peak inspiratory pressure (PIP) (28.2 +/- 1.5 versus 35.6 +/- 1.7 cm H2O, p < 0.05), an unchanged plateau pressure, and a higher mean airway pressure (MAP) (17.8 +/- 0.8 versus 15.6 +/- 0.5 cm H2O, p < 0.05) than CV. No significant difference in Pa(O2) and shunt fraction (QS/QT) was observed (83 +/- 7 mm Hg and 40 +/- 4% in CV versus 92 +/- 14 mm Hg and 35 +/- 3% in IRV, respectively). The Pa(CO2) was lower in IRV (48 +/- 3 versus 55 +/- 5 mm Hg, p < 0.05). Cardiac index (CI) and oxygen delivery (D(O2)) were lower in IRV (3.7 +/- 0.4 L/min/m2 and 500 +/- 61 ml/min/m2 versus 4.6 +/- 0.5 L/min/m2 and 617 +/- 80 ml/min/m2, respectively, p = 0.05 for both). Regardless of the considered parameter, no significant difference was observed between results after 1, 2, 4, and 6 h in each mode. We conclude that IRV at a ratio that results in a significant intrinsic PEEP does not improve Pa(O2), enhances CO2 elimination, decreases cardiac output (CO), and does not exert any time-dependent effect.

Adult↗

PubMed1997

Infant arousals during mother-infant bed sharing: implications for infant sleep and sudden infant death syndrome research.

OBJECTIVE: Normative values for infant sleep architecture have been established exclusively in the solitary sleeping environment. However, most of the world's cultures practice some form of parent-infant cosleeping. In addition, no previous polysomnographic studies in infants examined the frequency of electroencephalogram (EEG) arousals. This is the first study to assess (a) EEG arousals in infants and their relationship to sleep stages; (b) the impact on arousals of mother-infant bed sharing; and (c) the temporal overlap of infant with maternal arousals during bed sharing. METHODOLOGY: Three nights of polysomnography were performed in 35 breastfeeding mother-infant pairs when the infants were 11 to 15 weeks old. An adaptation night was followed by one bed sharing night and one solitary sleeping night. Twenty infants had been bed sharing since birth and 15 were routine solitary sleepers. Both epochal awakenings (EWs), based on 30-second epoch scoring of sleep-wake stages, and more transient arousals (TAs) >/=3 seconds were quantified. RESULTS: Stage 3-4 sleep was associated with a striking paucity of EWs and TAs compared with stages 1-2 or rapid eye movement sleep. Bed sharing facilitated EWs and TAs selectively during stage 3-4 sleep. EWs from stage 3-4 sleep were more frequent on the bed sharing night than on the solitary night in both infant groups. Routinely bed sharing infants also exhibited more frequent TAs in stage 3-4 than the routine solitary sleepers in both conditions. In both groups, the number of infant arousals (EWs + TAs) that overlapped the mother's was doubled during bed sharing, with infant arousals leading most often. CONCLUSIONS: Mother-infant bed sharing promotes infant arousals. Together with a previous report that bed sharing reduces stage 3-4 sleep, this suggests that normative values for infant sleep must be interpreted within the context of the sleeping environment in which they were established. Given that arousability is diminished in stage 3-4, we speculate that, under otherwise safe conditions, the observed changes in stage 3-4 sleep and arousals associated with bed sharing might be protective to infants at risk for SIDS because of a hypothesized arousal deficit. The responsivity of the mother to infant arousals during bed sharing might also be protective.

Analysis of Variance↗

PubMed1997

Health insurance coverage among foreign-born US residents: the impact of race, ethnicity, and length of residence.

OBJECTIVES: This study examined the health insurance status of the US foreign-born population and the influence of race, ethnicity, and length of residence on health insurance status. METHODS: Data were obtained from the 1989 and 1990 National Health Interview Surveys, including the Insurance and Family Resource Supplements. RESULTS: In 1989 and 1990, the foreign-born population was twice as likely as the US-born population to be uninsured (26.2% vs 13.0%). The highest rate of uninsured status, 40.8%, was found among foreign-born Hispanics. Persons who had lived in the United States for less than 15 years were 1.5 to 4.7 times more likely to be uninsured than were US-born Whites. CONCLUSIONS: Foreign-born US residents-especially Hispanics and persons residing in the United States for less than 15 years-are vulnerable to not having health insurance, which may limit their access to medical services. The administrative criteria for public programs may explain the high rates of uninsured status among recent immigrants. Recently enacted federal legislation could substantially increase the number of uninsured among the US foreign-born population, with profound public health implications.

Adolescent↗

PubMed1997

Treatment of inflamed pterygium and pinguecula with topical indomethacin 0.1% solution.

PURPOSE: To evaluate the effect of topical indomethacin 0.1% on signs and symptoms in inflamed pterygium and pinguecula. METHODS: Fifty-one consecutive patients who had inflamed pterygium (n = 32) or pinguecula (n = 19) were studied in a randomized, double-masked, controlled way. Objective signs (conjunctival congestion, redness, edema, and staining of cornea) and subjective complaints (photophobia, pain, foreign-body sensation, discomfort, and tearing) were evaluated and scored. In addition, we evaluated total signs, total symptoms, and total score. Group 1 (n = 25) received topical indomethacin 0.1% solution and group 2 (n = 26) received a placebo six times daily for 3 days, then four times daily for 11 days. Patients were examined before and at days 3, 7, and 14 after the treatment began. RESULTS: In group 1 at day 3, the scores of total signs, total symptoms, and total score decreased (p = 0.001), and they further decreased after 14 days (p = 0.02 to p = 0.05). In group 2 at day 3 these parameters also significantly decreased (p = 0.01 to p = 0.02), but no further improvement occurred after 14 days. Comparing groups 1 and 2 revealed a decrease in scores in group 1 for total signs, total symptoms, and total score at days 3, 7, and 14 (p = 0.03 to p = 0.002) except for total signs after 14 days (p = NS). All the patients reported mild stinging for < 1 min after administration of the drops. CONCLUSIONS: This study indicates that topical indomethacin solution 0.1% is a useful treatment for inflamed pterygium and pinguecula.

Administration, Topical↗