[Cardiovascular risk in patients with chronic renal failure. Patients in renal replacement therapy]

Dialysis patients constitute a high-risk subset of patients for developing cardiovascular disease, which accounts for nearly 50% of deaths. After stratification for age, race and gender, cardiovascular mortality is 10-20 times higher in dialysis patients than in the general population. Cardiovascular disease in this population cannot be fully explained by the high prevalence of classical cardiovascular risk factors (age, hypertension, diabetes, hyperlipidemia, smoking, etc.). Thus, the involvement of "new" cardiovascular risk factors (hyperhomocysteinemia, hyperfibrinogenemia, high lipoprotein (a) levels, oxidative stress, inflammation, etc.), and uremia-related factors (anemia, impaired calcium-phosphorus metabolism, hyperparathyroidism, accumulation of endogenous inhibitors of nitric oxide synthesis, etc.) has been also invoked to play a role in the increased cardiovascular risk in these patients. Endothelial dysfunction is the initial event in the development of atherosclerosis. Uremic patients exhibit an endothelial dysfunction, even before starting dialysis, which persists o is even aggravated under dialysis treatment. Uremic patients must be considered at high risk of developing cardiovascular disease. Thus cardiovascular risk factors in these patients should be managed early, aggressive and multifactorially in order to reduce their high cardiovascular morbidity and mortality.

The impact of managed care on the use of outpatient mental health and substance abuse services in Puerto Rico

This paper estimates the impact of managed care on use of mental health services by residents of low-income areas in Puerto Rico. A quasi-experimental design evaluates the impact of a low capitation rate on a minority population using three waves of data from a random community sample. Results indicate that two years after introducing managed care, privatization of mental health services had minimal impact on use. Advocates had hoped health care reform would increase access in comparison to access seen within the public system, while opponents feared profit motives would lead to decreased access. Neither forecast turned out to be correct. The question remains as to how to improve access for the poor with low capitation rates.

[Factors associated with the level of anxiety of nursing personnel taking care of HIV positive patients]

The objective of the study was to measure the level of HIV/AIDS related anxiety among hospital nursing staff and identify its determinants. Data were obtained through anonymous self administered questionnaire distributed to 222 nurses. The rasge anxiety and the HIV/AIDS attitudes were the most determinants of the anxiety level in the participants. Specifically, negative HIV/AIDS attitudes was associated with raise in state anxiety level, as well as high level of rasge anxiety was associated with high level of state anxiety. In conclusion, it is necessary to provide to the participants update trainings that included different aspects of HIV infection, as well as, anxiety management when caring for persons with HIV/AIDS.

Does managed mental health care reallocate resources to those with greater need for services?

Evidence points to the existence of two coexisting inefficiencies in mental health care resource allocation: those with need receive too limited or no care while those with no apparent need receive services. In addition to reducing costs, managed mental health care is expected to reallocate treatment resources to those with greater need for services. However, there are no empirical findings regarding this issue. This study tests whether managed mental health care has had a differential impact by level of need. Data consist of three waves of a community sample with a control group. The study finds that managed care has not succeeded in reallocating resources from the unlikely to the definite "needers."

Screening of active lyssavirus infection in wild bat populations by viral RNA detection on oropharyngeal swabs

Brain analysis cannot be used for the investigation of active lyssavirus infection in healthy bats because most bat species are protected by conservation directives. Consequently, serology remains the only tool for performing virological studies on natural bat populations; however, the presence of antibodies merely reflects past exposure to the virus and is not a valid marker of active infection. This work describes a new nested reverse transcription (RT)-PCR technique specifically designed for the detection of the European bat virus 1 on oropharyngeal swabs obtained from bats but also able to amplify RNA from the remaining rabies-related lyssaviruses in brain samples. The technique was successfully used for surveillance of a serotine bat (Eptesicus serotinus) colony involved in a case of human exposure, in which 15 out of 71 oropharyngeal swabs were positive. Lyssavirus infection was detected on 13 oropharyngeal swabs but in only 5 brains out of the 34 animals from which simultaneous brain and oropharyngeal samples had been taken. The lyssavirus involved could be rapidly identified by automatic sequencing of the RT-PCR products obtained from 14 brains and three bat oropharyngeal swabs. In conclusion, RT-PCR using oropharyngeal swabs will permit screening of wild bat populations for active lyssavirus infection, for research or epidemiological purposes, in line not only with conservation policies but also in a more efficient manner than classical detection techniques used on the brain.

Changes in access to mental health care among the poor and nonpoor: results from the health care reform in Puerto Rico

OBJECTIVES

Health care reforms associated with managed care may adversely affect the health care safety net for disadvantaged populations. This study compared changes in health care use among poor and nonpoor individuals enrolled in managed care.

METHODS

Data from 3 waves of a random community sample were collected on approximately 3,000 adults. Changes in use of mental health services were assessed in a pretest-posttest, quasi-experimental design.

RESULTS

Managed care increased use of specialty services among the nonpoor while maintaining the same level of use for the poor in the public sector.

CONCLUSIONS

Reallocation of mental health services may be a result of expanding Medicaid eligibility.

Environmental implications on the oxygenation of gasoline with ethanol in the metropolitan area of Mexico City

Motor vehicle emission tests were performed on 12 in-use light duty vehicles, made up of the most representative emission control technologies in Mexico City: no catalyst, oxidative catalyst, and three way catalyst. Exhaust regulated (CO, NOx, and hydrocarbons) and toxic (benzene, formaldehyde, acetaldehyde, and 1,3-butadiene) emissions were evaluated for MTBE (5 vol %)- and ethanol (3, 6, and 10 vol %)-gasoline blends. The most significant overall emissions variations derived from the use of 6 vol % ethanol (relative to a 5% MTBE base gasoline) were 16% decrease in CO, 28% reduction in formaldehyde, and 80% increase in acetaldehyde emissions. A 26% reduction in CO emissions from the oldest fleet (< MY 1991, without catalytic converter), which represents about 44% of the in-use light duty vehicles in Mexico city, can be attained when using 6 vol% ethanol-gasoline, without significant variation in hydrocarbons and NOx emissions, when compared with a 5% vol MTBE-gasoline. On the basis of the emissions results, an estimation of the change in the motor vehicle emissions of the metropolitan area of Mexico city was calculated for the year 2010 if ethanol were to be used instead of MTBE, and the outcome was a considerable decrease in all regulated and toxic emissions, despite the growing motor vehicle population.

Clustering of missense mutations in the C-terminal region of factor H in atypical hemolytic uremic syndrome

Hemolytic-uremic syndrome (HUS) is a microvasculature disorder leading to microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Most cases of HUS are associated with epidemics of diarrhea caused by verocytotoxin-producing bacteria, but atypical cases of HUS not associated with diarrhea (aHUS) also occur. Early studies describing the association of aHUS with deficiencies of factor H suggested a role for this complement regulator in aHUS. Molecular evidence of factor H involvement in aHUS was first provided by Warwicker et al., who demonstrated that aHUS segregated with the chromosome 1q region containing the factor H gene (HF1) and who identified a mutation in HF1 in a case of familial aHUS with normal levels of factor H. We have performed the mutational screening of the HF1 gene in a novel series of 13 Spanish patients with aHUS who present normal complement profiles and whose plasma levels of factor H are, with one exception, within the normal range. These studies have resulted in the identification of five novel HF1 mutations in four of the patients. Allele HF1 Delta exon2, a genomic deletion of exon 2, produces a null HF1 allele and results in plasma levels of factor H that are 50% of normal. T956M, W1183L, L1189R, and V1197A are missense mutations that alter amino acid residues in the C-terminal portion of factor H, within a region--SCR16-SCR20--that is involved in the binding to solid-phase C3b and to negatively charged cellular structures. This remarkable clustering of mutations in HF1 suggests that a specific dysfunction in the protection of cellular surfaces by factor H is a major pathogenic condition underlying aHUS.

[Non-convulsive status epilepticus secondary to adjusted cefepime doses in patients with chronic renal failure]

Fever is one of the most frequent causes of hospital admission in patients with end-stage renal disease. Lack of an identified source of infection and/or lack of clinical response to the first empirical antibiotic treatment favour the use of broader spectrum antibiotics. The availability of fourth-generation cephalosporins (e.g. cefepime) and the increasing incidence of bacterial resistances to classical antibiotics has increased their use in the clinical practice. We present two cases of non-convulsive status epilepticus in patients with advanced chronic renal failure who received cefepime at doses corrected for the degree of renal function according to the manufacturer's instrument as. The clinical symptoms included shouthough, processes, disorientation, loss of attention, and the later appearance of myoclonus. In both cases the electroencephalogram (EEG) was compatible with non-convulsive epileptic status. After cefepime withdrawal there was a clinical remission of symptoms and normalization of the EEG. It is concluded that cefepime treatment can induce a non-convulsive epileptic status in patients with advanced chronic renal failure. Pharmacokinetic studies are urgently needed to clearly define the appropriate dose of cefepime in patients with advanced chronic renal failure.

[Increased adrenomedullin levels in hypertensive patients on maintenance hemodialysis]

Hypertension is a frequent finding in uremic patients. The pathogenesis of this complication in uremia is complex and not fully elucidated. An imbalance between the vasoconstrictor and vasodilator systems may be involved in its pathogenesis. In this study we have evaluated the state of nitric oxide (NO) and adrenomedullin (ADM) in hemodialyzed patients, especially those with hypertension. We included a group of hypertensive hemodialyzed patients (n = 9) and a group of normotensive control patients (n = 10). We measured plasma renin activity, as well as plasma catecholamines, ADM, and nitrite/nitrate levels in basal conditions before starting the hemodialysis session. Plasma volume, as well as left ventricular ejection fraction were also measured. Hemodialysis patients showed plasma levels of nitrite/nitrates and ADM higher than the reference values in the normal population. We observed no differences in the plasma levels of nitrite/nitrates, but ADM levels were higher in hypertensive (278.2 +/- 15.5 pg/ml) patients than in normotensive patients (225 +/- 9.9 pg/ml) (p < 0.05). When considering all patients together, mean arterial pressure positively correlated with plasma ADM (r = 0.468, p < 0.05). Plasma volume and left ventricular ejection fraction were similar in the two groups of patients. In summary, plasma levels of nitrite/nitrates and ADM are increased in hemodialyzed patients, although only ADM levels were further increased in hypertensive patients. Our results do not suggest that a decreased production in the vasodilator factors evaluated is involved in the pathogenesis of hypertension in uremic patients.

Serum cystatin C as a new marker for noninvasive estimation of glomerular filtration rate and as a marker for early renal impairment

Cystatin C is a nonglycosylated basic protein produced at a constant rate by all investigated nucleated cells. It is freely filtered by the renal glomeruli and primarily catabolized in the tubuli (not secreted or reabsorbed as an intact molecule). Because serum cystatin C concentration is independent of age, sex, and muscle mass, it has been postulated to be an improved marker of glomerular filtration rate (GFR) compared with serum creatinine level. We compared serum cystatin C level with other markers of GFR, such as serum creatinine level and creatinine clearance, and analyzed their variations based on iothalamate labeled with iodine 125 ((125)I-iothalamate) clearance ((125)I-ICl), used as the gold standard for GFR. The concentrations of the two different markers of GFR in patients with impaired renal function were classified according to (125)I-ICl. Twenty individuals with normal renal function ((125)I-ICl, 128 +/- 23 mL/min/1.73 m(2)) were used as the control group. Serum cystatin C level showed a greater sensitivity (93.4%) than serum creatinine level (86.8%). Also, serum cystatin C showed the greatest proportion of increased values in patients with impaired renal function (100%) compared with serum creatinine level (92.15%). Serum cystatin C levels started to increase to greater than normal values when GFR was 88 mL/min/1.73 m(2), whereas serum creatinine level began to increase when GFR was 75 mL/min/1.73 m(2). These data suggest that measurement of serum cystatin C may be useful to estimate GFR, especially to detect mild reductions in GFR, and therefore may be important in the detection of early renal insufficiency in a variety of renal diseases for which early treatment is critical.

Effect of methyl tertiary butyl ether concentrations on exhaust emissions from gasoline used in the metropolitan area of Mexico City

In this work, the primary objective was to assess the impact of oxygenated fuel on the exhaust emissions from an important fraction of vehicles in the Metropolitan Area of Mexico City (MAMC). The results aim to provide information on the actual effect of MTBE on a fleet that represents more than 60% of the in-use vehicles in the MAMC. Ten vehicles were tested with a low-octane base gasoline, and 10 more with a regular-grade unleaded base gasoline. Three MTBE concentrations, 5, 10, and 15 vol %, were tested following the U.S. Federal Test Procedure (FTP). CO, total HC, and NOx from the exhaust gases were quantitatively evaluated and also characterized for FTP speciated organic emissions. From this data, the O3-forming potential of the fuels was calculated. Results show that for the fleet using low-octane gasoline, the addition of 10% MTBE substantially reduced CO emissions, but total HC concentration in the exhaust showed a modest decrease. For the regular gasoline, the 10% MTBE blend seemed to be the best choice, but there was not a significant decrease in emissions. The specific reactivity of each fuel, expressed in grams of O3 per gram of nonmethane organic gases, increased with MTBE concentration in both cases. This result is important to consider, especially for a region like Mexico City, which has high atmospheric O3 concentrations.

Increased plasma adrenomedullin levels in hemodialysis patients with sustained hypotension

BACKGROUND

Sustained hypotension in end-stage renal disease patients is characterized, despite an overactivation of the sympathetic and renin-angiotensin systems, by decreased vascular resistance and a blunted vascular response to pressor stimuli. An increased production of one or more vasodilator substances might play a role in the reduced vascular resistance and response to pressor stimuli in these patients. We evaluated the possible role of an increased production of nitric oxide and/or adrenomedullin (ADM) in the pathophysiology of chronic hypotension in hemodialysis (HD) patients.

METHODS

Three groups of hypotensive (N = 9), normotensive (N = 10), and hypertensive (N = 9) HD patients were included in the study. Plasma renin activity (PRA) and plasma levels of catecholamines, ADM, nitrite/nitrate (an estimator of nitric oxide production), tumor necrosis factor (TNF), and interleukin-1beta (IL-1beta) were measured. Plasma volume and left ventricular ejection fraction (LVEF) were also evaluated.

RESULTS

Plasma levels of nitrite/nitrate and ADM were elevated in HD patients with respect to the reference values in normal subjects. Plasma ADM levels, but not nitrite/nitrate levels, were higher in hypotensive (368.1 +/- 25.4 pg/mL) than normotensive (225 +/- 9.9 pg/mL) and hypertensive HD patients (278.2 +/- 15.5 pg/mL, P < 0.01). When considering hypotensive and normotensive patients together, the mean blood pressure inversely correlated with time on HD (r = -0. 53, P < 0.05) and plasma ADM levels (r = -0.78, P < 0.01).

CONCLUSIONS

Plasma ADM and nitrite/nitrate levels are increased in HD patients, but only ADM levels were higher in hypotensive than in normotensive and hypertensive HD patients. The higher plasma levels of this peptide in hypotensive patients and its inverse correlation with mean arterial pressure suggest that ADM may be involved in the pathophysiology of chronic hypotension in HD patients.

[Anti-glomerular basement membrane disease: a new disease causing fever of unknown origin?]

Antiglomerular basement membrane disease is an autoimmune disorder characterized by the presence of antibodies directed against glomerular basement membrane. Pyrexia of unknown origin (PUO) is defined as temperatures higher than 38.3 degrees C on several occasions, with a duration of more than 3 weeks, and failure to reach a diagnosis despite 1 week of in-patient investigation. There is a large list of causes of PUO including infections, malignancies and autoimmune diseases, but antiglomerular basement disease has not been described as a cause. We present the first case of antiglomerular basement disease which presented with PUO.

Characterization of monoclonal antibodies against apolipoproteins A-I and A-II. Epitope expression in LpA-I and LpA-I:A-II particles

Two monoclonal antibodies (MAbs) against apolipoprotein A-I (apo A-I), 6B9 and FF9B10, and one MAb against apolipoprotein A-II (apo A-II), 3F5, were characterized. To establish the epitope of apo A-I recognized by these antibodies, different experimental approaches were performed. First, competition between MAbs and the related epitopes on the same antigen was performed using double-determinant tests with previously characterized MAbs. Second, competition of different synthetic peptides of apo A-I in solution with apo A-I immobilized to solid phase was carried out. The MAbs against apo A-I (6B9 and FF9B10) appear to recognize discontinuous epitopes located in the amino-terminal region of the apo A-I. In competition experiments MAb 3F5 did not recognize central- or carboxy-terminal peptides of apo A-II. Furthermore, apo A-II was stronger recognized when it was included in HDL or LpA-I:A-II than in its purified form. So the epitope for 3F5 is better expressed in the lipoprotein structure. Finally, to establish the epitopes expression in different antigens in solution, competition of purified apo A-I, apo A-II, LpA-I, and LpA-I:A-II particles or HDL3, with apo A-I or HDL immobilized to solid phase, was carried out. The results showed that both MAbs against apo A-I reacted with poor affinity against free apo A-I, with high and similar affinities against Lp A-I and Lp A-I:A-II lipoparticles and with the highest affinity against HDL3. The MAb 3F5 against apo A-II recognized only LpA-I:A-II and not LpA-I lipoparticles.

[Factors related to initiation, type and length of breast feeding among participants and non-participants in prenatal breast feeding education at a local hospital]

The objective of this study was to determine the factors associated to initiation, type and duration of breastfeeding among participants and non-participants in prenatal breastfeeding classes at a local hospital (n = 153). Pre-experimental study design was used. The participants of the study were selected by simple systematic random sampling. Median age of participants was 28 years and 85% were married at the moment of the interview. 88.9% began to breast feed at some time and of these 32% breastfed for six months. Average number of school years completed by participants was 15.1 with a standard deviation of 1.9 years. The inferential results reflected statistical association between participation in prenatal breastfeeding classes and the initiation, type and duration of breastfeeding. Multiple regression results indicate a positive relationship between duration of breastfeeding and participation in breastfeeding support groups, after controlling for all factors of the conceptual model. The results of this study give support for hospital and community initiatives for increasing the incidence of breastfeeding and for extending the duration of breastfeeding. It is further recommended that continued education courses be offered to health professionals on breastfeeding techniques.

Prevalence of DSM-IV disorders in children and adolescents with asthma versus diabetes

OBJECTIVE

To evaluate the relationships between asthma and type and incidence of psychiatric problems in a pediatric population.

METHODS

A series of 93 children and adolescents with asthma presenting during a 1-year period to a pediatric pneumology and allergy service was studied. Their psychopathological problems were compared with those of 93 children with insulin-dependent diabetes mellitus (IDDM). Various questionnaires were completed by the patients: the Child Depression Inventory (CDI), the State-Trait Anxiety Inventory for Children (STAIC), and the Coopersmith Self-Esteem Inventory (SEI). Their parents were administered the Child Behavior Checklist (CBCL). The patients were examined using the revised Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS-R).

RESULTS

There were more symptoms in the asthma group than in the IDDM group, as indicated by total CBCL scores, internalization and externalization CBCL subscores, and the STAIC scores. Asthma was often associated with Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) psychiatric disorders. We found 30 anxiety disorders, 5 affective disorders, and 6 disruptive behaviour disorders. Asthmatic children did not seem to be more depressed than the IDDM group, and their self-esteem, overall, was good. However, the asthma subgroup presenting with psychiatric disorders had poorer self-esteem and social competence. Adolescents did not seem to suffer more psychiatric disturbances than did younger patients. Girls did not suffer more psychiatric disturbances than did boys.

CONCLUSION

Asthma appears to be associated both with higher overall incidence of psychiatric problems than in IDDM and with particular categories of psychiatric problems. In particular, the problems include anxiety disorders, internalizing symptoms, and disruptive behaviours.

[Sociodemographic profile of a group of sex workers in Puerto Rico]

This research explored the sociodemographic characteristics, the health perceptions and the distinctive aspects of the sexual work of a group of women sexual workers (n = 311). The study interest was generating data relative to the use of injectable drugs, the prevalence of sexually transmitted diseases (STD), the prevalence of HIV and the risk behaviors of this population group. A remarkable characteristic of the group of women studied was their history of pregnancies at and early age. A high proportion of illness apparently related to the presence of sexually transmitted diseases and limited health care was observed.

The association between Crohn disease and the myelodysplastic syndromes. Report of 3 cases and review of the literature

We report 3 patients who developed Crohn disease and myelodysplastic syndrome concurrently and review 9 previously reported cases of this association. Demographic and clinical features, treatment, and outcome are presented from previous reports and our own 3 cases. Of the 12 patients, 8 were men, and the mean age was 68.8 years (range, 28-83 yr). The geographic origin was heterogeneous. Pancytopenia was found in 5 patients, anemia in 5, and bicytopenia in 2. The classification types of myelodysplastic syndrome were variable. The marrow karyotype was reported in 10 patients: it was abnormal in 5, with chromosome 20 abnormalities in 3. Crohn disease and myelodysplasia were diagnosed simultaneously in 5 patients, whereas Crohn disease antedated myelodysplasia in 4 patients (interval, 8 mo-30 yr) and myelodysplasia antedated Crohn disease in 3 patients (interval, 2 mo-4 yr). Signs and symptoms of Crohn disease improved in most patients upon specific medical treatment. However, the outcome of myelodysplastic syndrome was not favorable in 10 of 11 patients in whom it was reported, with 4 deaths due to myelodysplasia-related complications. Notably, the activity of myelodysplasia in 1 of our own patients paralleled the clinical activity of Crohn disease, and hematologic abnormalities of the myelodysplasia resolved upon successful treatment of the Crohn disease, thus strengthening the hypothesis of a pathogenetic link between the disorders. The possibility of myelodysplastic syndrome should be considered in patients with Crohn disease over the age of 50 years who have peripheral blood cytopenias. Likewise, a diagnosis of Crohn disease should be considered in patients with myelodysplastic syndrome who develop gastrointestinal symptoms such as chronic and/or bloody diarrhea. In patients with such an association, the possibility of improvement of the myelodysplasia upon successful therapy of Crohn disease should not be ruled out.

Social networks and patterns of use among the poor with mental health problems in Puerto Rico

OBJECTIVES

This study uses the recently developed Network-Episode Model (NEM) to examine the nature and correlates of utilization among Puerto Ricans reporting mental health problems. The NEM highlights two issues: (1) examining the patterns or combinations of lay and formal use that individuals employ and (2) reformulating how the availability and content of social networks influences patterns of care.

METHODS

Using data from the 1989 Mental Health Care Utilization Among Puerto Ricans Study (probability sample of 1,777 individuals living in low-income areas of the island), the authors focus on the patterns and correlates of use for 365 Puerto Ricans reporting service use for mental health problems in the previous year.

RESULTS

A combination of clustering and multinomial logit techniques indicates that there are six unique care patterns. Two patterns include the use of mental health providers and are associated with different contingencies.

CONCLUSIONS

In general, patterns of use are shaped by age, education, gender, and illness severity. Larger, more supportive networks decrease the use of patterns of care that include formal health care providers, and decrease direct entry into the mental health sector. These results are in line with NEM's predictions for lower class populations and help clarify inconsistencies in previous research on social networks. The implications of this perspective for health services research and treatment are discussed.