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A Ponce de León

Publications and source records attributed to A Ponce de León.

10 recordsLinked to original sources
PubMed2000

Clinical consequences and transmissibility of drug-resistant tuberculosis in southern Mexico.

BACKGROUND: Consequences of drug-resistant tuberculosis (TB) in developing countries using directly observed treatment, short-course (DOTS), are not well defined. OBJECTIVE: To determine the impact of drug resistance on clinical outcome and transmission of TB under programmatic conditions. PATIENTS AND METHODS: A prospective cohort and molecular epidemiologic study was conducted in southern Mexico. Between March 1995 and February 1998 all patients with persistent cough whose sputa had acid-fast bacilli (AFB) underwent clinical and mycobacteriologic evaluation (species identification, drug susceptibility testing, and IS6110-based genotyping). Treatment was provided in accordance with Mexico's National Tuberculosis Program. Clinical and microbiologic outcomes and molecular epidemiologically defined transmission were measured. RESULTS: Mycobacterium tuberculosis was isolated from 238 of the 284 AFB smear-positive persons. The overall rate of resistance was 28.4% (new, 20.7%; retreated, 54.7%), and 10.8% (new, 3.3%; retreated, 35.8%) had multi-drug-resistant TB (ie, resistance to isoniazid and rifampin). After treatment, 75% (new, 81.0%; retreated, 52.8%) were cured, 8% (new, 7.8%; retreated, 7.5%) abandoned therapy, 9% (new, 3.9%; retreated, 28.3%) had treatment failure, and 4% (new, 3.3%; retreated, 7.5%) died. Another 2% of patients relapsed, and 9% died during a median of 24.4 months of follow-up. Drug-resistance was a strong independent risk factor for treatment failure. Being infected with multi-drug-resistant TB was the only factor associated with a decreased likelihood of being in a restriction fragment length polymorphism cluster. CONCLUSIONS: Despite the use of DOTS, patients with drug-resistant TB had a dramatically increased probability of treatment failure and death. Although multi-drug-resistant TB may have a decreased propensity to spread and cause disease, it has a profoundly negative impact on TB control.

Adult↗
PubMed1998

Time-series analysis of air pollution and cause-specific mortality.

Ten large European cities provided data on daily air pollution as well as mortality from respiratory and cardiovascular mortality. We used Poisson autoregressive models that controlled for trend, season, influenza epidemics, and meteorologic influences to assess the short-term effects of air pollution at each city. We then compared and pooled the city-specific results in a meta-analysis. The pooled relative risks of daily deaths from cardiovascular conditions were 1.02 [95% confidence interval (CI) = 1.01-1.04] for a 50 microg/m3 increment in the concentration of black smoke and 1.04 (95% CI = 1.01-1.06) for an increase in sulfur dioxide levels in western European cities. For respiratory diseases, these figures were 1.04 (95% CI = 1.02-1.07) and 1.05 (95% CI = 1.03-1.07), respectively. These associations were not found in the five central European cities. Eight-hour averages of ozone were also moderately associated with daily mortality in western European cities (relative risk = 1.02; 95% CI = 1.00-1.03 for cardiovascular conditions and relative risk = 1.06; 95% CI = 1.02-1.10 for respiratory conditions). Nitrogen dioxide did not show consistent relations with daily mortality. These results are similar to previously published data and add credence to the causal interpretation of these associations at levels of air pollution close to or lower than current European standards.

Aged↗
PubMed1997

X chromosome evolution in the suni and eland antelope: detection of homologous regions by fluorescence in situ hybridization and G-banding.

Comparative cytogenetics and fluorescence in situ hybridization (FISH) were used to track structural rearrangements in the X chromosomes of two African antelope species, the eland (Taurotragus oryx; tribe Tragelaphini) and the suni (Neotragus moschatus; tribe Neotragini). Using two microdissected cattle chromosome painting probes (one specific for Xp-containing sequences corresponding to Xp24-->p12 of the cattle X, and one specific for Xq-containing sequences corresponding to Xq12-->qter), we show that intrachromosomal rearrangements distinguish the X chromosomes of these species. Furthermore, there is clear evidence that, superimposed on this background of intrachromosomal evolutionary change, the sequences contained in the cattle Xp painting probe appear to have moved as a complete unit during the repatterning of the bovid X. Although we are unable to infer the order of the rearranged chromosomal segments, given the large regions of homology detected by the chromosome paints, we nonetheless believe that this approach (combining conventional and molecular cytogenetic studies on the X chromosome) will prove useful for inferring phylogenetic relationships in the family Bovidae, particularly as more probes become available.

Animals↗
PubMed1990

A study on the venous drainage of 150 cerebral arteriovenous malformations as related to haemorrhagic risks and size of the lesion.

In this paper we study the venous drainage of 150 cerebral arteriovenous malformations (AVM), correlating the number of efferent veins with the symptoms of clinical onset and with the size of the lesions. Statistical analysis demonstrates that those AVM's which in the angiograms show only one draining vein have a high risk of haemorrhage. As the number of drainage veins increases, this bleeding risk decreases, becoming quite low in angiomas with multiple drainage veins, which we denominate "medusa-head angiomas". Statistics also demonstrate that small angiomas (less than 2 centimeter on diameter) usually have only one drainage vein, thus carrying a high risk of haemorrhage. As their size increase, so do the number of veins, and the possibility of haemorrhage decreases.

Adolescent↗
PubMed1990

Enterotoxins and adhesins of enterotoxigenic Escherichia coli: are they risk factors for acute diarrhea in the community?

A cohort of 228 Mexican children less than 5 years old was followed during the enterotoxigenic Escherichia coli(ETEC) season. The incidence of ETEC diarrhea-associated and asymptomatic infections was determined, and E. coli strains isolated from stool samples were tested for heat-labile and heat-stable toxins and for expression of colonization factor antigens (CFA). Of the children, 61% had at least one ETEC infection. Children with ETEC isolated from stools were more likely to have diarrhea than were ETEC-free age-matched control children (odds ratio [OR] = 4.5; 95% confidence interval [CI] = 2.9-7.0). Strains carrying CFA/IV, CFA/I, or CFA/II were found in 23%, 18%, and 5% of ETEC infections, respectively. The risk of having diarrhea associated with a CFA-expressing versus a CFA-negative ETEC strain was the same (age-adjusted OR = 0.8; 95% CI = 0.4-1.6). These data should be considered in the development of a diarrhea vaccine containing only CFAs.

Adhesins, Escherichia coli↗
PubMedDate not supplied

[Coccidioides immitis: primary infection of the central nervous system. Case report and literature review].

A case of primary coccidiodal meningitis without pulmonary, osseous or dermic affection due to Coccidioides immitis in a 27 years old male patient with hypertensive brain of one month of evolution, was reported. The patient was resident of Northern California, and he was previously healthy. The cerebrospinal fluid (CSF) showed a glucose of 22 mg/dL, proteins 62 mg/dL, white blood cells 100/mm3 (97% PMN, 3% MN). CT SCAN showed bilateral ventricular dilatation. Diagnosis of coccidioidal meningitis was made based on antibodies against anticoccidioides (IgM 6.8 mg/dL and IgG 4.9 mg/dL, normal < 2 mg/dL) and growth of Coccidioides immitis. The chest radiograph was normal and the detection of antibodies against human immunodeficiency virus was negative. A VP shunt was placed and the patient was treated with intravenous amphotericin B and intratecal amphotericin B through on Ommaya reservoir. Even with antifungal treatment the patient deteriorated neurologically after an initial transient improvement, he died two weeks later in his hometown.

Adult↗
PubMedDate not supplied

Diastasis of the maxillary bone: an unusual complication of transsphenoidal surgery.

Diastasis of the intermaxillary suture is an unusual complication of the transsphenoidal approach to the sella turcica. Over the 1977-1989 twelve-year-period, 192 procedures were performed at our Center. This complication occurred only once, in a senile patient with marked osteoporosis. It did not alter the course of the operation, nor did it create additional problems during the postoperative period.

Adenoma↗