Gerardo C. Palacios

Audiologic and vestibular findings in a sample of Human Immunodeficiency Virus type-1-infected Mexican children under Highly Active Antiretroviral Therapy

OBJECTIVE There is little information about audiologic and vestibular disorders in pediatric patients infected with the Human Immunodeficiency Virus type-1 (HIV-1). The aim of this study was to evaluate audiologic and vestibular disorders in a sample of HIV-1-infected children receiving Highly Active Antiretroviral Therapy. METHODS Patients underwent pure tone audiometry, speech discrimination testing, auditory brainstem responses, electronystagmography, and rotatory testing. HIV-1 viral load and absolute CD4+ cell counts were registered. RESULTS Twenty-three patients were included, aged 4.5 years (median, range 5 months to 16 years). Pure tone audiometry was carried out in 12 children over 4 years of age: 4 (33%) showed hearing loss, 2 were conductive. Auditory brainstem responses were measured in all 23 patients, suggesting conductive hearing loss in 6 and sensorineural hearing loss in 2. Most patients with conductive hearing loss had the antecedent of acute or chronic suppurative otitis media but with dry ears at the time of evaluation (p=0.003). Abnormal prolongations of interwave intervals in auditory brainstem responses were observed in 3 children (13%, 4 ears), an abnormal morphology in different components of auditory brainstem responses in 4 (17.4%, 7 ears), and abnormal amplitude patterns in 11 patients (48%, 17 ears). Vestibular tests were abnormal in all six patients tested, with asymmetries in caloric and rotatory tests. Although differences were not significant, in general, audiologic abnormalities were more frequent in patients with more prolonged HIV-1 infections, higher viral loads, or lower absolute CD4+ cell counts. CONCLUSIONS Conductive hearing loss associated with previous otitis media events, abnormalities in auditory brainstem responses suggesting disorders at different levels of the auditory pathways, and unilateral vestibular hyporeflexia were frequent findings in our sample of HIV-1-infected children under Highly Active Antiretroviral Therapy. These findings suggest that HIV-1-infected children should be submitted to audiologic and vestibular evaluation as early as possible in order to reduce their impact on the psychosocial development of these patients.

Knowledge of the brain death concept by personnel in Spanish and Latin-American healthcare centers

Background The knowledge and acceptance of the concept of brain death (BD) among health care personnel is fundamental. Objective To analyze the level of understanding of the BD concept among personnel in Spanish and Latin American healthcare centers and to determine the factors affecting this attitude. Material and methods Data from 12 hospitals and 32 primary care centers in 4 countries within the International Collaborative Donor Project were selected (Spain, Mexico, Cuba and Costa Rica (n = 4378)). Results 62% of the personnel (n = 2714) understood BD and believed that this was the death of an individual. Of the rest, 30% (n = 1 333) did not understand it and the remaining 8% (n = 331) believed it did not mean the death of a patient. 83% (n = 931) of physicians understood BD, compared to 75% (n = 895) of nurses, 55% (n = 299) of healthcare assistants, 53% (n = 108) of non-healthcare university-educated personnel and 36% (n = 481) of those without a university education (p<0.001). 68% (n = 1084) of Mexicans understood BD compared to 66% (n = 134) of Cubans, 58% (n = 1411) of Spaniards, and 52% (n = 85) (p<0.001) of Costa Ricans. There were significant relationships between knowledge of the concept and the following: type of healthcare center (p<0.001), clinical service (p<0.001), having spoken about organ donation within the family (p<0.001) and ones partners attitude to the subject (p<0.001). A direct relationship has been found between understanding the concept and attitude toward deceased donation (p<0.001). Conclusions The understanding of BD by personnel from healthcare centers was not as good as expected. There were marked differences depending on job category.

Level of acceptance of solid organ xenotransplantation among personnel in Spanish, Mexican, and Cuban hospitals

Xenotransplantation is still a long way from becoming a clinical reality. However, in an emergency situation, it could be used as a bridge for replacing vital organs until the arrival of a human organ. To analyze the attitude toward xenotransplantation among hospital personnel from several hospitals in Spain and Latin America.

Response to Two Consecutive Protease Inhibitor Combination Therapy Regimens in a Cohort of HIV-1-infected Children

The response to 2 consecutive protease inhibitor (PI) combination regimens was evaluated in a cohort of HIV-1-infected children. Twelve children, most of whom had been heavily treated, received a 3-drug treatment: saquinavir in hard gelatin capsules (SQVhgc) + zidovudine (ZDV) + didanosine. When this treatment failed it was replaced by a 4-drug regimen: ritonavir + SQVhgc + ZDV + lamivudine. A mild and temporary decrease in viral load (VL) was observed with the initial regimen (p=0.22). Therapy failure occurred in 7 patients (58%) within 9 months and in another 3 (25%) within 9-18 months. The 7 children who failed within 9 months received the subsequent boosted regimen, leading to a significant and lasting reduction in VL ( p = 0.001). None of the patients failed on the boosted regimen: 5/7 achieved a VL of < 400 copies/ml and 3/7 achieved a VL of < 50 copies/ml. Our results suggest that a 4-drug regimen including 2 PIs produces a better and more sustained response than a 3-drug regimen including only 1 PI, and that a good, sustained response is possible with subsequent boosted regimens even in heavily treated children.

Identification of the High-Virulence Clone of Group B Streptococci in Mexican Isolates by Growth Characteristics at 40°C

Abstract. Group B streptococci (GBS) colonizing the vagina and rectum of pregnant women cause invasive disease of the offspring in a small number of cases. The immune status of the host and differences in virulence among strains appear to be the main determinants for neonatal infection. A high-virulence clone (HVC) was proposed to cause much of the morbidity and mortality when a collection of GBS isolates was examined by multilocus enzyme electrophoresis. HVC isolates could be further distinguished by their inability to grow at 40°C. This characteristic was used in the present study to examine a collection of 57 GBS isolates from Mexico City for the HVC. Three serotype III invasive strains were classified in the HVC. The other eleven invasive strains and all carrier isolates had growth curves unaffected at 40°C. These results demonstrate the presence of the HVC in Mexico. Such a low prevalence could explain in part the low rate of GBS invasive neonatal disease in Mexico.

Opinion toward living liver donation of hospital personnel from units related to organ donation and transplantation: a multicenter study from Spain and latin-america.

Background: Hospital personnel of services related to donation and transplantation process play a fundamental role in the development of transplantation. Objectives: The aim of this study was to investigate the attitude toward living liver donation (LLD) among hospital personnel from services related to donation and transplantation in hospital centers in Spain and Latin America. Materials and Methods: Eight hospitals within the “International Donor Collaborative Project” were selected, three in Spain, three in Mexico and two in Cuba. The study was performed in transplant-related services, using a randomized sample, which was stratified by the type of service and job category. Results: In total, 878 workers were surveyed of which 82% (n = 720) were in favor of related LLD, 10% (n = 90) were against and 8% (n = 68) undecided. Attitudes toward related LLD were more favorable in the following groups: the Latin Americans (86% in favor vs. 77% among the Spanish; P = 0.007); younger people (37 vs. 40 years, P = 0.002); those in favor of either deceased donation (P < 0.001) or living kidney donation (P < 0.001); those who believed that they might need a transplant in the future (P < 0.001); those who would accept a liver from a living donor (P < 0.001); those who discussed the subject of donation and transplantation with their families (P = 0.040); and those whose partner was in favor of donation and transplantation (P = 0.044). Conclusions: Personnel from donation and transplantation-related units had a favorable attitude toward LLD. This attitude was not affected by psychosocial factors, although it was influenced by factors directly and indirectly related to the donation and transplantation process.

Structured interruptions of highly active antiretroviral therapy in cycles of 4 weeks off/12 weeks on therapy in children having a chronically undetectable viral load cause progressively smaller viral rebounds

OBJECTIVES To evaluate the viral, immune and clinical impact of a structured treatment interruption (STI) program of highly active antiretroviral therapy (HAART) in three cycles of 4 weeks off/12 weeks on therapy in a cohort of children with HIV infection under chronic viral control. METHODS Using a single-group time series experimentation design and following informed consent, the HAART of children with HIV and a chronically undetectable viral load (VL) was discontinued for 4 weeks and then restarted and continued for 12 weeks for a total of three cycles. The VL, CD4+/CD8+ lymphocytes, and clinical status were evaluated at the end of each STI and at 6 and 12 weeks after HAART was resumed. RESULTS Four children with a median age of 10.3 years (range 6.5-11.2 years) were included in the study. Their clinical immune categories were: A1 (n=2), A2 (n=1), and B3 (n=1). Treatment of all four patients was with zidovudine (AZT)+lamivudine (3TC)+ritonavir (RTV). At the end of the first STI, VL was a median 214000 copies/ml (range 27400-616000), corresponding to 5.3 log(10) (range 4.4-5.8). At the end of the second STI, VL was a median 72400 copies/ml (range 17800-126000) or 4.7 log(10) (range 4.2-5.1), which corresponds to a rebound 0.6 log(10) lower than the first. At the end of the third STI, VL was a median 28200 copies/ml (range 5370-140000) or 4.45 log(10) (range 3.7-5.1), a rebound 0.85 log(10) lower than the first. All rebounds were followed by a decrease in the VL to undetectable levels during the treatment periods. CD8+ T lymphocyte counts increased during viral rebounds and an initial decrease in CD4+ T lymphocyte counts was followed by a tendency to increase even exceeding CD8+ T cell counts. Only one event of transitory severe immunosuppression occurred. There were no symptoms related to the HIV infection. CONCLUSIONS The STI of HAART in cycles of 4 weeks off/12 weeks on therapy in children with chronically undetectable VL can cause progressively lower viral rebounds followed by a decrease to undetectable levels, with a low risk of severe immunosuppression and without the occurrence of symptoms related to HIV.

High-Virulence Clone of Group B Streptococci Unable to Grow at High Temperatures Is Present in Serotypes Other Than Type III

Highly virulent clonotypes of serotype III seem to cause much of the perinatal morbidity and mortality attributed to Streptococcus agalactiae (group B streptococci, GBS), One of these clonal types, designated the “high-virulence clone” (HVC), was identified by its inability to grow at 40°C in a chemically defined medium. In the present study, this inability to grow at high temperatures was used as a marker to identify HVC in a sample of 286 Mexican GBS isolates. Forty-three isolates (15%) were identified as belonging to this clone: 15 were invasive isolates, 33 were serotype III (77%), and 10 were of serotypes other than type III (23%). These results demonstrate that HVC is more prevalent in Mexico than previously reported and that this clone is not restricted to serotype III isolates.

Identification of the High-Virulence Clone of Group B Streptococci by Using a Probe Containing a Putative Aldolase Gene

A high-virulence clone (HVC) was proposed as causing much of the morbidity and mortality when a collection of group B Streptococcus (GBS) isolates was examined by multi-locus enzyme electrophoresis. HVC isolates could be further distinguished by their inability to grow at 40°C, and a temperature-sensitive aldolase was identified as responsible for this characteristic. In the present study, the HVC was sought in a collection of 57 GBS isolates by hybridization with a probe containing a putative aldolase gene on genomic DNA restriction enzyme digests. Isolates were initially classified as HVC or non-HVC by their inability to grow at 40°C. Three serotype III invasive isolates had the HVC control restriction/hybridization pattern. They were also unable to grow at 40°C. The remaining 11 invasive and all carrier isolates showed a pattern identical to that of the non-HVC control. These results provide additional support for the existence of a highly virulent clonal group among serotype III isolates and suggest that hybridization with a probe containing the aldolase gene on DNA restriction enzyme digests can be an alternative method for identifying highly virulent isolates.

Subclinical metabolic abnormalities associated with obesity in prepubertal Mexican schoolchildren.

ABSTRACT Childhood obesity has increased to epidemic levels and is considered a public health problem due to its association with a number of metabolic abnormalities, which are being detected at earlier stages of life. The objective was to evaluate the association between the presence of subclinical metabolic abnormalities (SMA) and obesity in a sample of pre–pubertal Mexican schoolchildren. Children of both sexes and 6 to 13 years old were questioned for signs of puberty, underwent anthropometric measurement and had their Body Mass Index (BMI) calculated. Two groups were formed: those with obesity (case group) and those with normal weight paired by age and chosen randomly (control group). Fasting insulin, glucose and cholesterol were measured. 92 children were included, 46 in each group, mean age 9.9 and 9.5 years old, respectively (p=0.97). A higher frequency of hyperinsulinism was found in the case group: Fasting insulin >15 mU/ml, 75% vs. 21% (case group vs. control group, respectively); fasting glucose to insulin ratio <6, 72% vs. 24%; HOMA IR >2.7, 83% vs. 14%; and decrease in QUICKI (<0.3), 80% vs. 19% (p=0.000). Hypercholesterolemia was 25% vs. 15% (p=0.22), impaired fasting glucose 28% vs. 8% (p=0.01), and family history of diabetes mellitus (DM) 35% vs. 9% (OR=5.6; 95%CI=1.5–22.2; p=0.002). In this sample of Mexican schoolchildren, obesity was associated to a higher frequency of SMA, such as hyperinsulinism and impaired fasting glucose, and to a family history of DM.