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Biomedical subjects

F A Lopez

Publications and source records attributed to F A Lopez.

At least 19 recordsLinked to original sources
PubMed2002

Disseminated Pseudallescheria boydii (Scedosporium apiospermum) infection in a renal transplant patient.

Transplant recipients receive a number of immunosuppressive medications that result in an increased risk of infection, including infections with microbes that are normally not pathogenic. We describe a patient with end-stage renal disease who underwent kidney transplantation. Six months postoperatively, he presented with a lesion on his ankle, multiple thigh nodules, and right testicular pain. Biopsy of the ankle lesion demonstrated Pseudallescheria boydii (Scedosporium apiospermum), a common environmental fungus. Following orchiectomy, multiple fungal elements were found that were initially described as Aspergillus species, but later identified as P. boydii. In addition, multiple brain abscesses were found on magnetic resonance imaging. Despite treatment with multiple antifungal medications, the patient died of cardiac dysrhythmia. Current diagnostic and therapeutic alternatives for P. boydii are reviewed.

Antifungal Agents↗
PubMed2001

Myonecrosis caused by Edwardsiella tarda: a case report and case series of extraintestinal E. tarda infections.

Edwardsiella tarda is an unusual human pathogen. It is primarily associated with gastrointestinal disease, although recent reports of extraintestinal disease are broadening the current understanding of the clinical spectrum of E. tarda. A series of 11 cases of extraintestinal E. tarda infection is presented, including the first reported case of myonecrosis in an immunocompetent patient. Wound infections were the most common manifestation, and 3 of 5 patients with infected wounds had been exposed to a marine environment. One patient had bacteremia, and the remaining 5 patients developed abscesses that required surgical drainage. Four patients had E. tarda isolated in pure culture, including the patient with myonecrosis. Although it is often difficult to ascertain the contribution of E. tarda to infection when it is isolated as part of a mixed culture, this case series suggests that E. tarda is singularly capable of causing limb- and life-threatening infections.

Adolescent↗
PubMed2001

Dermatologic infections in the immunocompromised (non-HIV) host.

The immunocompromised host's susceptibility to infections often present a difficult diagnostic challenge to the physician. A working knowledge of the host immune defenses and microbiologic complications that can occur when these functions are compromised provides a more focused framework for further evaluation and management. Infections in these patients are often morbid and life-threatening, creating an urgent need for prompt diagnosis. The skin may manifest the first clue(s) of a serious underlying infection. Appropriate workup and diagnosis of cutaneous lesions provide an expeditious, noninvasive, and potentially life-saving approach to the immunocompromised host with a dermatologic infection.

Humans↗
PubMed2001

Dyspnea in a woman infected with the human immunodeficiency virus.

Shortness of breath is a common complaint encountered in both the ambulatory and acute care setting. In patients infected with the human immunodeficiency virus, dyspnea often heralds the onset of a potentially life-threatening opportunistic infection. We present a case of a rare cause of dyspnea in the general population and to our knowledge the first such case reported in the setting of human immunodeficiency virus infection in the United States.

Adult↗
PubMed2001

A predictable outcome of a preventable disease.

Infective endocarditis is a systemic illness that can present with a variety of non-specific clinical symptoms. Patients with certain underlying heart valve abnormalities are at increased risk for development of infective endocarditis while undergoing minor procedures, particularly those associated with bacteremia by pathogens that typically cause infective endocarditis. We present a case of infective endocarditis that developed after a dental procedure in a patient with a previously undetected congential bicuspid aortic valve.

Adult↗
PubMed2000

Evolution of nutritional status of infants infected with the human immunodeficiency virus.

CONTEXT: There are today only a limited number of studies defining growth parameters and nutritional status for HIV children. OBJECTIVE: To study the nutritional status of infants infected with the human immunodeficiency virus. TYPE OF STUDY: Longitudinal study. SETTING: Department of Pediatrics, Faculty of Medical Sciences, UNICAMP, Campinas, Brazil. PARTICIPANTS: One hundred and twenty-four children born to HIV infected mothers were evaluated from birth until the age of two years. They were subdivided into two groups: 71 infected children and 53 non-infected children. MAIN MEASUREMENTS: Growth was evaluated in both groups by comparing Z-scores for weight/age (w/a), length/age (H/a) and weight/length (w/H) (using the NCHS curves as reference). RESULTS: The Z-score analyses showed that there was a significant difference between the two groups for all the variables studied, except for the H/a value at 3 months of age and the W/H value at 21 months of age, which showed P > 0.05. CONCLUSIONS: The growth of infected infants was observed to be severely affected in comparison with that of seroreversed infants in the same age groups. Although clinical manifestations may take time to appear, the onset of growth changes begin soon after birth.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Molecular characterization of Cyclospora-like organisms from baboons.

Cyclospora organisms are intestinal pathogens of humans that are increasingly recognized in many parts of the world; yet, the reservoirs and host range remain poorly defined. Analysis of 18S ribosomal DNA (rDNA) suggests that the human-associated Cyclospora species (Cyc-hu) is most closely related to the Eimeria species, which are host species-specific. Recently, oocysts identical to those of Cyc-hu were detected in baboon fecal specimens from Tanzania. The 18S rDNA from 3 of these baboon-associated oocyst specimens was amplified and sequenced. Phylogenetic analysis indicated that these baboon-associated Cyclospora-like organisms (Cyc-bab) are nearly identical to each other and are distinct from Cyc-hu (1.6%-1.7% dissimilar); however, these Cyc-bab organisms are the closest known relatives of Cyc-hu. Together, these primate-associated cyclosporans constitute a coherent clade within the diverse group of Eimeria species. These findings raise important questions about the evolutionary relationships of the eimeriids and Cyc-hu host range and should lead to improved polymerase chain reaction-based diagnostics.

Animals↗
PubMed1998

Outcomes of obese children and adolescents enrolled in a multidisciplinary health program.

OBJECTIVE: The study was designed to evaluate the impact of a multidisciplinary program on children and adolescents' weight control. DESIGN: Retrospective study regarding changes in relative weight of all patients treated regularly in an out-patient care public service between January 1992 and December 1993. SUBJECTS: 198 children and adolescents (108 girls and 90 boys; mean age: 9.25y; mean body mass index (BMI): 24.26 kg/m2, range 19.1-40.31). MEASUREMENTS: Anthropometric data collected at the visits were obtained until June 30 1994. BMI compared to reference data was used. Dual Photon X-ray Absorptiometry (DEXA) was used for 64 patients, to determine percent body fat. RESULTS: Relative weight at the last visit was significantly lower when compared with initial relative weight for the whole sample. Significantly better outcome of relative weight was obtained when six or more visits occurred for the whole sample, and for girls when the days' interval between visits was shorter than 52 d. Variables such as percent body fat, body shape at the first visit, family obesity pattern, length of obesity and pubertal stage, did not significantly influence the outcome of relative weight for the subjects during the treatment. CONCLUSION: Results obtained indicated that good outcomes can be obtained in a program using nutrition education focused on small modifications of eating habits in order to avoid excess energy intake. The best predictors of weight improvement for children and adolescents participating in the program were the higher frequency of visits and shorter intervals between them.

Adolescent↗
PubMed1998

Scedosporium apiospermum (Pseudallescheria boydii) infection in a heart transplant recipient: a case of mistaken identity.

We report a case of fatal central nervous system infection with Scedosporium apiospermum (Pseudallescheria boydii) in a heart transplant recipient. This ubiquitous fungus is known to cause mycetoma and localized infections in patients with otherwise normal conditions. Disseminated infections occur rarely and are seen primarily in patients who are receiving immunosuppressive medications or who have neutropenia. Often life-threatening when infection is disseminated and involves the central nervous system, this diagnosis is difficult to make rapidly because S. apiospermum (P. boydii) mimics Aspergillus spp. and Fusarium spp., both clinically and histopathologically. Imidazoles such as miconazole, but not amphotericin B, are considered the therapeutic compounds of choice. Improved diagnostic and treatment options are needed to optimize management of infections with S. apiospermum (P. boydii).

Adult↗
PubMed1994

Preliminary study of treatment of sulphuric pickling water waste from steelmaking by bio-oxidation with Thiobacillus ferrooxidans.

This report looks at the laboratory-scale recovery of iron oxides (alpha Fe2O3 type) through bio-oxidation with Thiobacillus ferrooxidans of the ferrous sulphate contained in steel industry sulphuric pickling liquors. This is done by calcining iron sulphates and iron and ammonium sulphates obtained from the crystallization of the oxidized solution. The products of the bacterial reaction and the iron oxides are then studied according to calcination temperature. The process carried out produced 50 kg of alpha Fe2O3 per m3 of waste pickling liquor at 700 degrees C with 99.8% weight iron recovery.

Ferrous Compounds↗
PubMed1993

Colostrum composition in adolescent mothers.

Colostrum of high and low (LSEL) socioeconomic level adolescent mothers was analyzed to determine the potential influence of adolescence on colostrum's chemical composition. Concentrations of total fat, energy, total protein, immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin G and fatty acids were compared to those of adult mothers. The colostrum of adolescent mothers showed significantly higher levels of IgA and IgM compared to that of adults. Concentrations of lauric, myristic, and palmitic acids were lower in the group of LSEL adolescents, when compared to those of adult mothers of the same socioeconomic level, probably due to lower lipogenic activity in the former. High levels of stearic and oleic acids were found in LSEL adolescents in comparison to LSEL adults, despite similar dietary habits. Our results show that breast-feeding by adolescent mothers of any socioeconomic level is as indicated as that by adult mothers.

Adolescent↗
PubMed1993

Airway obstruction and ventilation-perfusion relationships in acute severe asthma.

We have investigated the time course of ventilation-perfusion (VA/Q) mismatch and airflow obstruction in 18 patients with acute severe asthma with the objective to identify potential differences according to the clinical severity of the attacks. Nine patients were hospitalized and nine were discharged (emergency room stay < 24 h) according to the clinical criteria of the attending physicians. Spirometry and VA/Q inequality (multiple inert gas technique) were measured within the first 6 h of treatment in the emergency room, and at Weeks 1,2,3, and 4 thereafter. In the emergency room [corrected] hospitalized patients (in relation to those discharged) showed lower airflow rates (FEV1, 31 +/- 3 versus 46 +/- 6% predicted SEM) and greater VA/Q mismatch (as assessed by the dispersion of blood flow distributions (logSD Q) (1.28 +/- 0.11 versus 0.92 +/- 0.11; normal values < 0.6). Even though the rate of improvement of airflow was similar in both groups (without returning to normal limits), VA/Q relationships improved at different rates in each group and reached normal values at the end of the study. Although in hospitalized patients the recovery of VA/Q abnormalities was delayed in relation to airflow rates, the time course in discharged patients was the same. Previous studies have shown a dissociation between spirometry and VA/Q inequality, suggesting that whereas airflow rates predominantly reflect bronchoconstriction of large airways, VA/Q mismatch is more related to obstructive changes in peripheral airways. Our results support this hypothesis and suggest that the more severe the asthma attacks, the more severe the obstructive changes involving peripheral airways for a given degree of widespread airway narrowing.

Acute Disease↗
PubMed1991

Fat and protein composition of mature milk in adolescents.

The levels of certain components, notably total protein, total fat, energy, and fatty acids, of mature milk from 48 adolescent and 44 adult mothers was studied. These two groups were subdivided into high and low socioeconomic level (SEL). All mothers were primiparous, eutrophic, and with term pregnancy; and their newborns weighted over 2500 g at birth. The age factor appeared to have significant influence on the concentration of total protein, with higher levels in the group of adolescent mothers possibly as a compensatory mechanism to maintain the caloric value of the milk. The fatty acid content was altered significantly by the SEL probably due to the direct effect of maternal diet. The milk in adolescent mothers of low SEL demonstrated higher concentration of lauric and myristic acids, while the milk in low SEL adults contained higher proportions of linoleic and linolenic acids. The milk in adult mothers of high SEL demonstrated higher concentrations of palmitic, palmitoleic, and oleic acids. The different feeding habits of two socioeconomic groups may explain these results. The regular intake of soya oil, corn oil, and margarine by the urban population in general resulted in higher levels of linoleic acid in the milk of all groups studied.

Adolescent↗
PubMed1985

Effects of acetone in heparin on the multiple inert gas elimination technique.

We have detected acetone in several brands of heparin. If uncorrected, this leads to errors in measuring acetone in blood collected in heparinized syringes, as in the multiple inert gas elimination technique for measuring ventilation-perfusion ratio (VA/Q) distributions. Error for acetone retention [R = arterial partial pressure-to-mixed venous partial pressure (P-V) ratio] is usually small, because R is normally near 1.0, and the error is similar in arterial and mixed venous samples. However, acetone excretion [E = mixed expired partial pressure (P-E)-to-P-V ratio] will appear erroneously low, because P-E is accurately measured in dry syringes, but P-V is overestimated. A physical model of a homogeneous alveolar lung at room temperature and without dead space shows: the magnitude of acetone E error depends upon the ratio of blood sample to heparinized saline volumes and acetone partial pressures, without correction, acetone E can be less than that of less soluble gases like ether, a situation incompatible with conventional gas exchange theory, and acetone R and E can be correctly calculated using the principle of mass balance if the acetone partial pressure in heparinized saline is known. Published data from multiple inert gas elimination experiments with acetone-free heparin, in our labs and others, are within the limits of experimental error. Thus the hypothesis that acetone E is anomalously low because of physiological mechanisms involving dead space tissue capacitance for acetone remains to be tested.

Acetone↗
PubMed1984

The mechanisms of arterial hypoxemia during hemodialysis.

Hypoxemia during hemodialysis has variously been attributed to worsening ventilation-perfusion (VA/Q) relationships, alveolar hypoventilation combined with a reduced respiratory quotient, increased right-to-left shunting, and diffusion impairment. It is difficult to separate out these various effects, which explains lack of agreement in the literature. To more critically evaluate the causes of hypoxemia during hemodialysis, we used a multiple inert gas elimination technique to determine the distribution of ventilation-perfusion ratios during hemodialysis in 8 patients with chronic renal failure. Measurements were made before, during (at 60, 120, and 210 min), and after hemodialysis. Whereas arterial PO2 fell from 87 to 74 mmHg by 120 min, ventilation-perfusion relationships actually improved. Cardiac output fell from 5.3 to 4.0 L/min over the same time. Alveolar ventilation, respiratory quotient, and alveolar PO2 all fell, and the alveolar arterial PO2 difference remained essentially unchanged. These findings suggest that the hypoxemia observed during hemodialysis is primarily due to a decrease in alveolar ventilation and respiratory quotient associated with removal of metabolic CO2 in the dialyzer. Secondary factors affecting arterial PO2 were the slight improvement in ventilation-perfusion relationships tending to increase it, and the decrease in cardiac output tending to decrease it. There was no evidence for diffusion impairment because the measured VA/Q inequality accounted for the degree of hypoxemia.

Arteries↗
PubMed1983

[Intrauterine malnutrition in rats. II. Study of weight and mortality of the offspring].

Rats were submitted to protein-calorie deprivation during different periods of gestation and the body weight and mortality of offspring were evaluated at 0, 28 and 90 days of age. The body weight was considered adequate (n) when the values were up to 2 SD below the mean values of control animals, or inadequate (d) when the values were below 2 SD. Rats of the control group (C) were fed ad libitum (protein 21%), and the rats of the experimental groups were fed during all gestational period (D), during the first half (D1) or second half of pregnancy (D2), with a diet containing 1% of protein, and the intake reduced to 50%. Significant differences were observed in the ponderal evolution for all experimental groups. Group D was the most damaged, with the greatest ponderal deficiency and the greatest mortality rates. Similar behavior was observed for D2. Group D1 was similar to C with the best results and the lowest mortality rate.

Animals↗