Biomedical subjects

L Cabrera

Publications and source records attributed to L Cabrera.

At least 19 recordsLinked to original sources

PubMed2005

Electronic microscopy and EDX characterization of Teotihuacan prehispanic mortar from the cave under the Sun Pyramid.

A cave (102 m long) under the structure of the Sun pyramid of the prehispanic Teotihuacan City indicates the importance of the pyramid. Studies of the cave mortar samples using energy dispersive X-ray (EDX) fluorescence, scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed no difference in the chemical elemental composition. The elements can be distributed in three groups: major, minor and trace elements. The minerals identified were compatible with the origins of the cave and with the magnetic pattern.

Journal Article↗

PubMed2003

Taenia solium infection in a rural community in the Peruvian Andes.

An epidemiological study was conducted in a highland, rural community in Peru, to determine the seroprevalences of human and porcine infection with Taenia solium and the risk factors associated with human infection. The seroprevalences, determined using an assay based on enzyme-linked-immuno-electrotransfer blots (EITB), were 21% (66/316) in the humans and 65% (32/49) in the pigs. The human subjects aged <30 years were more likely to be positive for anti-T. solium antibodies than the older subjects (P < 0.001). The risk factors associated with human seropositivity were lack of education beyond the elementary level [odds ratio (OR)=2.69; 95% confidence interval (CI)=1.09-6.65] and pig-raising (OR=1.68; CI=0.96-2.92). Curiously, sheep-raising was inversely associated with human T. solium infection (OR=0.50; CI=0.28-0.90). The study site appears to be a new endemic focus for T. solium in the central Peruvian Andes. Although, in earlier studies, the seroprevalence of T. solium infection has generally been found to increase with age, the opposite trend was observed in the present study. The results of follow-up studies should help determine if the relatively high seroprevalence in the young subjects of the present study is the result of a transient antibody response.

Adolescent↗

PubMed2003

Stability studies of tablets containing 5 mg of policosanol.

The stability studies of tablets containing 5 mg of policosanol, a new cholesterol lowering drug, were conducted to predict an expiration date and to search the appearance of putative degradation products. All quality parameters such as colour, moisture content, hardness, disintegration, policosanol content and microbiological limits of the tablets were assessed. The effect of extreme treatments such as acid and basic hydrolysis, oxidative and photolytic degradation as well as thermal degradation, on the policosanol content was studied. In addition, studies under extreme conditions of storage [(40 +/- 2) degree C and (75 +/- 5)% R.H.] as well as 37, 45, 55 and 60 degrees C combined with 50, 75 and 92% R.H.) and under ambient conditions of storage for climatic zones II and IV were performed. These studies demonstrate that these tablets are a stable pharmaceutical formulation, without significant changes in their quality criteria at the stressed conditions used, so that policosanol content remains unchanged during the entire studies. The chromatographic profile of the samples after 9 months of thermal degradation shows chromatographic peaks that corresponds to the palmitate and stearate esters of octacosanoyl, triacontanoyl and hexacosanoyl, being the only degradation products observed on these studies.

Anticholesteremic Agents↗

PubMed2001

Posttreatment follow-up of Helicobacter pylori infection using a stool antigen immunoassay.

The Helicobacter pylori stool antigen enzyme immunoassay (HpSA) was evaluated during posttreatment follow-up of patients in a country with a very high prevalence of H. pylori infection. From among 273 dyspeptic individuals (18 to 55 years) initially recruited from a shantytown in Lima, Peru, 238 participants who met the inclusion criteria and were suspected to be H. pylori positive based on (14)C urea breath test (UBT) results underwent endoscopy. Participants with endoscopy-proven infections received standard eradication therapy and were monitored by UBT and HpSA at 1 month following treatment and at 3-month intervals for 9 months posttreatment. A second endoscopy was performed if UBT results showed evidence of treatment failure or H. pylori recurrence. Biopsy results were considered the "gold standard" in all analyses. Among patients who underwent endoscopy, HpSA had a pretreatment sensitivity of 93%. Two-hundred thirty patients completed the treatment regimen, of whom 201 (93%) were considered to have had successful treatment outcomes based on a negative follow-up UBT. Thirty-two patients with UBT-defined treatment failures or H. pylori recurrences at any point during the 9-month follow-up underwent a second endoscopy. In the posttreatment setting, HpSA had an overall sensitivity of 73% and a specificity of 67%. Agreement between UBT and HpSA diminished throughout the follow-up. Among 14 participants in whom HpSA remained positive at 1 month following treatment despite UBT evidence of treatment success, 12 (86%) became HpSA negative within 3 months posttreatment. Although this study confirmed the validity of the HpSA in the initial assessment of dyspeptic patients, the test demonstrated a reduced overall accuracy in the detection of treatment failures and H. pylori recurrences during 9 months of posttreatment follow-up. Furthermore, in some patients it may take up to 3 months after successful eradication for antigen shedding to diminish to levels within the negative HpSA range.

Adolescent↗

PubMed2001

Urinary selenium excretion in patients with cervical uterine cancer.

In this work, we report on a relationship between urinary selenium and the development of cervical uterine cancer. A simple chemical method was developed to concentrate trace amounts of selenium from relatively large urine samples by use of small activated carbon filters. When these filters are irradiated with thermal neutrons, selenium can be determined either by 77mSe (t1/2 = 17.5 s) or 75Se (t1/2 = 120 d). In this article, we report the results for 82 urine samples from women with cervical uterine cancer in several stages of development and from healthy controls. These results show a statistically significant increase of selenium excretion in cancer patients as compared to controls. Urinary selenium excretion is highest for patients in the intermediate stages of the disease.

Adult↗

PubMed2001

Acute Helicobacter pylori infection is followed by an increase in diarrheal disease among Peruvian children.

BACKGROUND: Cohort and case-crossover studies were conducted to evaluate whether new Helicobacter pylori infections are followed by increased diarrhea. METHODS: Participants were 6-month-old to 12-year-old shantytown residents living near Lima, Peru. Baseline data were collected from community households. Health interviews were completed daily, and sera, drawn every 4 months, were tested for H pylori immunoglobulin G. Diarrhea rates among newly H pylori-infected (seroconverting) children were compared with rates among persistently uninfected and infected children using cohort and case-crossover analyses. RESULTS: Sera were obtained from 345 children from January 1, 1995, through September 1, 1997. H pylori incidence was 12% per year (36 H pylori infections in 109 866 seronegative days). In adjusted cohort analyses, seroconverters had more diarrhea days (rate ratio: 2.0; 95% confidence interval: 1.6-2.4), episodes, and sick days in the year after infection than did uninfected children; and more diarrhea days and sick days than did persistently infected children. This effect was strongest in the first 2 months. Case-crossover analyses supported these findings. CONCLUSION: Preventing H pylori infection may help reduce pediatric diarrheal disease.

Acute Disease↗

PubMed2001

Assessment of hospital costs related to the diagnosis and treatment of upper gastrointestinal haemorrhages in patients consuming non steroid anti-inflammatory drugs.

BACKGROUND: Non-steroid anti-inflammatory drugs (NSAIDs) can produce haemorrhages of the digestive tract, whose treatment result in significant hospital costs. OBJECTIVE: The aim of this analysis has been to estimate hospital costs related to the treatment of digestive haemorrhages potentially caused by the intake of NSAIDs. MATERIAL AND METHODS: The study was conducted by reviewing the clinical history of all patients admitted in two tertiary Spanish hospitals during 1998 due to digestive haemorrhage following NSAID treatment. After the identification of cases, all resources consumed during their hospitalisation (concomitant medication, complementary examinations and tests, surgery, blood products consumption, inpatient consultations and length of stay in the hospital) until the complete resolution of each case, were recorded. RESULTS: Thirty-six percent of patients admitted due to digestive haemorrhage had taken some NSAID the same day of their hospitalisation (85.4%) or in previous days. The cost related to the treatment of these patients amounted to some 71 million pesetas for both hospitals, with a cost/patient of 434,407 pesetas. CONCLUSIONS: Given the high consumption of NSAIDs in our normal clinical setting, costs related to the diagnosis and treatment of digestive haemorrhages in hospitals are a highly significant burden for the National Health System.

Adolescent↗

PubMed2001

[Severe gastrointestinal complications potentially associated with the use of non-steroidal anti-inflammatory agents: hospital treatment costs for the National Health System of our country].

BACKGROUND: Non-steroidal antiinflammatory drugs (NSAIDs) produce severe gastrointestinal (G-I) complications in 1-4% of cases which need to be treated into the hospital. The aim of this study has been to assess the hospital cost secondary to treat these complications in our National Health Service (NHS). MATERIAL AND METHODS: In the first phase a cross-sectional study was performed in order to know the number of patients who were hospitalized due to a severe G-I complication during 1998 in two tertiary hospital in our country. It was reviewed their clinical charts to know whether they had taken any NSAIDs. In those positive cases all resources used during the hospitalization were collected. RESULTS: In both hospitals studied 38.1% of hospitalized patients for a severe G-I complication had taken any NSAIDs during the same day or previous days. The cost/patient was of 389,831 pesetas. During 1998 in the whole NHS there were 54,623 hospitalizations owing to the same reason. Assuming that 38.1% of them had also taken any NSAIDs, 20,811 patients would have suffered a severe G-I complication potentially due to the intake of NSAIDs. Extrapolating the cost/patient obtained in both hospitals to the global number of patients hospitalized into the NHS, the cost of treating all severe G-I complications related to the consumption of NSAIDs during 1998 was of 8,112 millions pesetas. CONCLUSIONS: Bearing in mind the elevated prevalence of osteo-articular pathology in our country and the high consumption of NSAIDs for its treatment, the coming of new therapeutic options with a better safety profile would mean an important resources' saving for our NHS.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2000

Identification of 5 types of Cryptosporidium parasites in children in Lima, Peru.

Cryptosporidium parvum is usually considered to be the pathogen responsible for human cryptosporidiosis. We genotyped Cryptosporidium in 132 stool specimens from 80 Peruvian children, representing 85 infection episodes, using techniques that differentiate Cryptosporidium species and C. parvum genotypes. Five types of Cryptosporidium were identified: C. parvum human (67), bovine (8), and dog (2) genotypes, C. meleagridis (7), and C. felis (1). Twenty-five (29%) of the 85 infection episodes were associated with diarrhea. There was no significant difference in age, antecedent stunting, percentage with diarrhea, or duration of diarrhea for episodes with human genotype, compared with those of zoonotic Cryptosporidium. Duration of oocyst shedding was longer for human genotype than for zoonotic Cryptosporidium (mean, 13.9 days and 6.4 days, respectively; P=.004). Serum samples from 8 children with C. meleagridis, C. felis, or C. parvum dog genotype were tested for anti-human immunodeficiency virus (HIV) type 1 antibodies; all were found to be negative. Contrary to common belief, novel Cryptosporidium species and C. parvum genotypes can infect HIV-negative children.

Animals↗

PubMed2000

Natural history of infection with Bartonella bacilliformis in a nonendemic population.

An investigation was performed after an outbreak of bartonellosis in a region of Peru nonendemic for this disorder. Symptoms of acute and chronic bartonellosis were recorded. Serological analysis was performed on 55% of the affected population (554 individuals), 77.5% of whom demonstrated previous infection with Bartonella bacilliformis. The attack rate of Oroya fever was 13.8% (123 cases); the case-fatality rate was 0.7%. The attack rate of verruga peruana was 17.6%. A new specific immunostain was developed and used to confirm the presence of B. bacilliformis in the biopsied skin lesions. Most seropositive individuals (56%) were asymptomatic. The symptoms that were associated with prior infection, as determined by Western blot, included fever (37.2% of the seropositive vs. 17.2% of the seronegative population; P<.001), bone and joint pain (27% vs. 9%; P<.001), headache (27% vs. 12.3%; P <.001), and skin lesions described as verruga peruana (26.8% vs. 4.9%; P<.001). Our findings suggest that infection with B. bacilliformis causes a broad spectrum of disease that is significantly milder in severity than that frequently reported.

Adolescent↗

PubMed2000

Gallstone disease in Peruvian coastal natives and highland migrants.

BACKGROUND: In a previous study, we found that gallstones were a common occurrence in the high altitude villages of the Peruvian Andes. AIMS: To determine if high altitude (> or = 1500 m) is a contributing risk factor for gallstone disease. METHODS: We conducted a cross sectional study in a periurban community in Lima, Peru, and compared the prevalence of gallstone disease between coastal natives, highland (Sierra) natives and Sierra natives who had migrated to the coast. We also compared the prevalence rates from this study with those from a previous study conducted at high altitude. We examined 1534 subjects >15 years of age for gallstone disease. Subjects were interviewed for the presence or absence of risk factors. RESULTS: Gallstone disease was more common in females (16.1 cases per 100, 95% CI 13.8-18.2) than in males (10.7 per 100, 95% CI 8.0-13.4). Females had a greater risk of gallstone disease, especially if they had used oral contraception and/or had four or more children. The age adjusted prevalence was not significantly different between coastal natives, Sierra migrants, and Andean villagers. The prevalence of gallstone disease was not associated with time since migration or with having native Sierra parents. After adjusting for other risk factors, Sierra natives who migrated to the coast had a lower prevalence of gallstone disease than coastal natives (odds ratio 0.74, 95% CI 0.58-0.94). CONCLUSIONS: This study indicates that high altitude is not a positive risk factor for gallstone disease and confirms that this disease is common in Peruvians, which may be attributable to Peruvian-Indian ethnicity.

Adolescent↗

PubMed1999

A placebo-controlled trial of Lactobacillus GG to prevent diarrhea in undernourished Peruvian children.

OBJECTIVE: Lactobacillus GG (L-GG), an acid- and bile-resistant strain that colonizes the intestinal mucosa, has been used to manage diarrhea in children. Our objective was to evaluate the prophylactic use of L-GG to prevent diarrhea in children at high risk from a developing country in a randomized, placebo-controlled trial. STUDY DESIGN: Two hundred four undernourished children 6 to 24 months old from an indigent peri-urban Peruvian town received either L-GG or placebo in flavored gelatin once daily, 6 days a week, for 15 months. Episodes of diarrhea were documented by daily home visits, and diagnostic studies were done in a subset of cases. Recovery of L-GG in stool from subjects and from family contacts was examined. RESULTS: Subjects in the L-GG group had significantly fewer episodes of diarrhea (5.21 episodes diarrhea/child/year ['ecy'] L-GG group, 6. 02 ecy placebo group; P =.028). The decreased incidence of diarrhea in the L-GG group was greatest in the 18- to 29-month age group (P =. 004) and was largely limited to nonbreastfed children (Breastfed: 6. 59 ecy L-GG, 6.32 ecy placebo, P =.7; Nonbreastfed: 4.69 ecy L-GG, 5. 86 ecy placebo, P =.005). The duration of diarrhea episodes and the causes of diarrhea were similar in both groups, except adenovirus was more common in the placebo group. CONCLUSION: L-GG supplementation may be useful as a prophylactic measure to control diarrhea in undernourished children at increased risk, especially nonbreastfed children in the toddler age group.

Breast Feeding↗

PubMed1998

Effects of Cryptosporidium parvum infection in Peruvian children: growth faltering and subsequent catch-up growth.

The authors conducted a 2-year (1989-1991) community-based longitudinal study in a shantytown in Lima, Peru, to examine the effect of Cryptosporidium parvum infection on child growth during the year following the onset of infection. A cohort of children, aged 0-3 months at recruitment, was followed monthly for anthropometrics, weekly for stool samples, and daily for diarrheal status. Data from 185 children in the cohort permitted a comparison of growth in C. parvum-infected and noninfected children. The analyses fitted smooth, flexible curves with a linear random-effects model to estimate growth differences between C. parvum-infected and noninfected children. Children infected with C. parvum experienced growth faltering, both in weight and in height, for several months after the onset of infection, followed by a period of catch-up growth. Younger children took longer to catch up in weight than did older children. Catch-up growth, however, did not occur in children infected between ages 0 and 5 months. These children did not catch up in height, and one year after infection they exhibited an average deficit of 0.95 cm (95% confidence interval (CI) 0.38-1.53) relative to noninfected children of similar age. Stunted children who became infected also did not catch up in either weight or height, and one year after infection they exhibited a height deficit of 1.05 cm (95% CI 0.46-1.66) relative to noninfected, stunted children of similar age. These results indicate that Cryptosporidium parvum has a lasting adverse effect on linear (height) growth, especially when acquired during infancy and when children are stunted before they become infected.

Animals↗

PubMed1998

Detection of Cyclospora cayetanensis in wastewater.

Cyclospora cayetanensis causes diarrheal disease worldwide without a confirmed mode of transmission. Wastewater was examined for the presence of this organism. Oocysts were detected microscopically, and their identity was confirmed by molecular techniques. These findings verify that current techniques can isolate Cyclospora oocysts and suggest that fecally contaminated water may act as a vehicle of transmission.

Animals↗

PubMed1997

Asymptomatic and symptomatic cryptosporidiosis: their acute effect on weight gain in Peruvian children.

This study investigated whether a child's first infection with Cryptosporidium parvum had an acute effect on weight gain. Specifically, the authors compared monthly rates of weight gain between C. parvum-infected and noninfected children. Over a 2-year period (1989-1991), a cohort of Peruvian children aged 0-3 months at recruitment were followed twice weekly for assessment of daily diarrheal status, weekly for C. parvum stool examinations, and monthly for anthropometric measurements. Data on 207 children permitted the authors to examine the effect of C. parvum infection on weight gain. During the 2-year study period, 45% (94/207) of the children became infected with C. parvum for the first time. Weight gain intervals in 57 of the 94 infected children met criteria for analysis. Of these, 63 percent (36/57) were asymptomatic (i.e., had no diarrhea). On average, children with symptomatic cryptosporidiosis gained (i.e., grew) 342 g less (95% confidence interval 167-517) during the first month of infection than did children without diarrhea who were not yet infected. The effect of asymptomatic cryptosporidiosis was less severe: On average, children with asymptomatic infection gained 162 g less (95% confidence interval 27-297) during the first month of infection than did children without diarrhea who were not yet infected. Symptomatic cryptosporidiosis retarded weight gain more than did asymptomatic cryptosporidiosis, but the latter was twice as common. Since asymptomatic cryptosporidiosis is more prevalent, it may have more of an overall adverse effect on child growth in the community than symptomatic cryptosporidiosis.

Acute Disease↗

PubMed1997

Epidemiology and treatment of Cyclospora cayetanensis infection in Peruvian children.

Cyclospora cayetanensis was detected in fecal specimens from 63 (1.1%) of 5,836 Peruvian children studied over 2 years; the protozoan was detected by modified acid-fast staining and autofluorescence under ultraviolet light. The highest prevalence occurred among children between 2 and 4 years of age. Thirty-two percent (20) of the 63 C. cayetanensis-infected children were symptomatic. Nineteen infected children were enrolled in a double-blind, placebo-controlled trial of a 3-day course of trimethoprim-sulfamethoxazole (TMP-SMZ; 5/25 mg/[kg x d]). Children were followed up with daily stool examinations (mean number of samples examined per child +/- SE, 19 +/- 4). The mean duration of oocyst excretion +/- SE was 4.8 +/- 1.2 days for TMP-SMZ recipients compared with 12.1 +/- 6.1 days for placebo recipients (P < .02). The prevalence of C. cayetanensis infection decreases during winter months and as children age; it decreases precipitously by adulthood. In children in areas of endemicity, C. cayetanensis usually causes mild disease that is often asymptomatic. TMP-SMZ therapy significantly decreases the duration of oocyst excretion.

Adolescent↗

PubMed1997

Isolation of Cryptosporidium parvum and Cyclospora cayetanensis from vegetables collected in markets of an endemic region in Peru.

Cryptosporidium parvum and Cyclospora cayetanensis are protozoan pathogens that cause prolonged diarrhea in both immunocompetent and immunocompromised hosts. Cryptosporidium parvum can be transmitted via the fecal-oral route, while the exact mechanisms of transmission of Cyclospora cayetanensis have not been fully determined. Humans appear to be the sole host for the latter and a distinct seasonality has been observed in endemic areas around the world. Samples of vegetables were collected at several small markets in a periurban slum in Peru during the seasons of high and low incidence. The vegetables were washed, the supernatants were collected and centrifuged, and the pellets were resuspended in a solution of 2.5% potassium dichromate. Pellets were examined using direct microscopic observation, acid-fast staining, and immunofluorescent assays for C. parvum and Cyclospora cayetanensis oocysts. Samples were collected during three time periods: the season of low incidence, the beginning of the season of high incidence, and end of the season of high incidence. Of the total vegetables examined, 14.5% contained C. parvum oocysts and 1.8% had Cyclospora oocysts. Thus, market vegetables may provide a route by which Cryptosporidium and Cyclospora can be transmitted. Our study also suggests that washing vegetables does not completely remove Cryptosporidium and Cyclospora oocysts.

Animals↗

PubMed1997

[Workshop on Molecular Epidemiology of Viral Diseases].

A workshop on viral epidemiology was held on September 29, 1995 at the Medical School of the Universidad Nacional Autónoma de Mexico. The aim of this workshop was to promote interaction among scientists working in viral epidemiology. Eighteen scientists from ten institutions presented their experiences and work. General aspects of the epidemiology of meaningful viral diseases in the country were discussed, and lectures presented on the rota, polio, respiratory syncytial, dengue, papiloma, rabies, VIH and hepatitis viruses.

Adult↗