Biomedical subjects
Publications and source records attributed to Y Gutierrez.
The first human infection with Gongylonema in Iran is reported in a 35-year-old Iranian woman with complaints of one year duration and treated as a psychotic patient. Two worms, a male, and a female, were retrieved, described, and identified as G. pulchrum based on their morphological characteristics.
This study examines patterns of growth and nutritional status of indigenous Tsimane' children under 9 years of age (n = 199 boys and 210 girls), based on a cross-sectional sample from 58 villages from the Beni Deparment of lowland Bolivia. Compared with US children, Tsimane' children are quite short, with linear growth tracking at or below the US 5th centile in both sexes. The prevalence of low height-for-age ("stunting;" HA Z-scores </=-2) is 52% in boys and 43% in girls. In contrast, weight-for-height in Tsimane' children approximates the US median, with the prevalence of low weight-for-height ("wasting"; WH Z-scores </=-2) being only 4% and 6% in boys and girls, respectively. Tsimane' boys and girls are leaner than their US peers, but their levels of body fatness are not so low as to indicate severe energy stress. Arm muscularity of Tsimane' children is similar to that of their US age peers, and this suggests that they are not experiencing acute protein malnutrition. Variation in measures of nutritional status of Tsimane' children is modestly correlated with village-level differences. Degree of isolation, as measured by distance to urban centers or to primary forest, was not a strong predictor of children's anthropometric status. Rather, in both boys and girls, nutritional status was most strongly associated with number of teachers in the village, a measure of access to education. Comparative analyses indicate that high levels of statural growth stunting are common among indigenous populations throughout lowland South America. This problem appears to be largely attributable to poor dietary quality (diets low in key micronutrients) and high disease loads. Further research is needed to identify the specific causes and potential interventions for the high rates of childhood growth stunting in this region.
The permeability of a series of 12 commercial solvents through living human skin were studied by using a topological sub-structural approach (TOPS-MODE). We first analyzed the influence of several physicochemical parameters used in describing the skin permeability of the solvents. No single significant relationship was found between any of these physicochemical properties and the permeability of the solvents. A QSAR model using TOPS-MODE descriptors was obtained and validated. This model accounted for more than 95% of the variance in the experimental permeability of these solvents. Using the derived model, the structural factors responsible for the permeability of this series of solvents through living human skin were identified. Methyl groups bonded to heteroatoms or to CH2 groups resulted in the greatest contributions to skin permeability and these groups were considered to be "permeability enhancers". In contrast, groups of the type X = O (X = S, C) were found to be "permeability inhibitors" because they possessed negative contributions to the logarithm of permeability in all of the studied solvents. Drawing on the idea of permeability "enhancers" and "inhibitors", we hypothesized that the solvents needed to orientate themselves in front of the stratum corneum layer first before penetrating through the skin.
AIM: To identify potential factors of change in alcohol consumption and regional differences which could explain why and how habits are evolving. SUBJECTS AND METHODS: Four hundred and thirty three subjects aged 20 to 34 years, were recruited by random sampling in Marseilles, Montpellier and Toulouse. A quantitative food frequency questionnaire was used to collect data on alcohol consumption. A stepwise logistic regression was applied to the total sample, to the sub-sample of drinkers, and to the sub-samples of drinkers of each type of alcoholic beverage. Factors associated with each type of alcoholic consumption were analyzed by city. RESULTS: Montpellier and Toulouse samples were pooled because of the similarity in alcoholic consumption, which was different from that in Marseilles. There are significantly more drinkers in Montpellier/Toulouse than in Marseilles (74.4% versus 53.8%; p=0.001) and also more binge drinking subjects (31.1% versus 10.3%; p=0.001). Age, tobacco, leisure physical activity are independently associated with alcoholic consumption, female sex and Marseilles, being inversely associated. These two last factors are similarly associated with binge drinking, as well as age. CONCLUSION: The study of the factors for alcoholic consumption by site suggests that differences in behavior could explain these results. These distinct characteristics should be considered when implementing anti-alcoholic prevention in youth.
A novel approach to the study of quantitative relationships between chromatographic parameters and the chemical structure is introduced. It is based on the computation of the spectral moments of the topological bond matrix by using different weights as diagonal entries of this matrix. The main advantage of the present approach is that the quantitative contributions of the structural fragments of molecules to the chromatographic parameters studied can be obtained explicitly. By using this approach we study two data sets: one composed of 156 alkanes and the other of 81 oxygen-containing organic molecules. In both cases excellent quantitative structure-chromatographic retention relationships were obtained. The contributions of the different fragments to the chromatographic retention were generated obtaining tables of additive contributions to the properties studied. The physicochemical interpretation of the results on the basis of the retention mechanisms is also analyzed in light of this new approach.
One worm recovered from the orbit of a patient in Indiana, and two from the peritoneal cavity of another patient in California are described and classified as Dirofilaria. Both patients were elderly men who have lived all their lives in the United States. The main morphologic feature of these three immature worms is the presence of a smooth cuticle devoid of longitudinal ridges, similar to the cuticle of D. immitis. However, because other dirofilariid with similar cuticular characteristics have been found in animals in the Western Hemisphere, and they cannot be conclusively ruled out as the cause of the infection in our patients, a diagnosis of D. immitis-like organism is proposed for these nematodes. The relationship of these worms to other dirofilariid of animals and humans on the American continent is important because of the diagnostic problems these infections posed to practicing pathologists.
Six patients suffering from an unusual form of colitis produced by Strongyloides stercoralis hyperinfection are described. In contrast to the usual Strongyloides hyperinfection syndrome, in which small intestinal and pulmonary manifestations are seen in patients with some forms of immunodeficiency, the patients described here presented with only a characteristic transmural eosinophilic granulomatous inflammation affecting mostly the colonic wall and clinically mimicking ulcerative colitis or Crohn's disease. This Strongyloides eosinophilic granulomatous enterocolitis apparently results from a florid inflammatory response by eosinophils, histiocytes, and giant cells with formation of granulomas that destroy the larvae entering the colon. This morphologic picture differs from that of the well-described hyperinfection syndrome, in which the bulk of the larvae pass through the colonic wall to complete the life cycle, with only a few larvae destroyed in the colon. The probable pathophysiologic mechanism of this unusual manifestation of hyperinfection is discussed based on the anatomic and clinical observations of patients who presented at different stages in the evolution of their condition and whose length of follow-up varied.
A 10-year review of the surgical pathology files of the Department of Pathology at Naples Community Hospital (Naples, FL, U.S.A.) revealed 10 cases of Dirofilaria tenuis and one of Dirofilaria ursi infection. The review consisted of only those lesions for which the pathologists had recorded the presence of a worm in the lesion. Therefore, an unknown number of subcutaneous lesions without parasites were not reviewed. Nine of the 11 cases of Dirofilaria were diagnosed as Dirofilaria or Dirofilaria tenuis originally. An additional case, previously diagnosed as Dirofilaria, was found to be a sparganum larva on review. This finding indicates that, because of the unfamiliarity of pathologists with the diagnostic characteristics of these nematode parasites, infections with Dirofilaria are underdiagnosed or misdiagnosed. If pathologists were more familiar with these parasites, their prevalence and the medical cost of this zoonosis in the southeastern United States could be determined more accurately.
The fourth case of zoonotic Dirofilaria repens infection in Israel is reported, and the diagnostic morphologic characteristics of this filariid are reviewed. The importance of the exact anatomic diagnosis of this filaria is stressed in view of the fact that Israel has pockets of settlers from East Africa, a region endemic for lymphatic filariasis (Wuchereria bancrofti). Since the possibility of introduction of such an infection into the country exists, differentiating this zoonotic Dirofilaria from other filarial worms is essential. The clinicopathological features of a Dirofilaria repens infection are distinct. The patient initially has a painful subcutaneous or conjunctival swelling; the excisional biopsy shows the presence of a dead or alive, usually female worm that measures 220-660 microns across; the central intestine and the genital organs (two uteri) are located in the pseudocoelom; the thick, multilayered cuticle is provided with 95-105 sharp, longitudinal ridges, the latter being separated from each other by a distance of 12 microns; the circumferential muscle cell layer, covering the inner side of the cuticle, is bilaterally interrupted by the large chord cells, two to five nuclei of which are discernible in each cross section.
The nutritional needs of pregnant adolescents are the greatest at a time when it is most difficult to meet them. Dieting, skipping meals, snacking, eating away from home, consuming fast foods, and trying unconventional diets are common eating behaviors among adolescents, which relate to their changing lifestyles of increased independence, busy schedules, search for self-identity, peer influence, group conformity, and body image dissatisfaction. Total nutritional needs of pregnant adolescents who are at least 2-year post-menarche are similar to those of pregnant adults. But, because of their poor dietary habits, they usually enter pregnancy with reduced nutrient stores and increased risk of nutritional deficiencies. All pregnant teens, therefore, should have their dietary habits assessed along with special dietary counseling, and vitamin-mineral supplements should be recommended if their usual nutritional intake is below standard. Also, the weight-gain pattern should be monitored to ensure that energy intakes are sufficient to support a gain of about 0.4 kg (1 lb) per week in the second and third trimester.
Skin biopsies from 221 parasitologically confirmed cases of tegumentary leishmaniasis caused by Leishmania braziliensis spp. were evaluated with respect to histopathology, the qualitative and quantitative nature of the cellular infiltrate, and the presence of Leishmania amastigotes. These variables were cross correlated with the Leishmania-specific immune response, clinical presentation, and response to treatment. Physical evidence of prior leishmanial lesions was associated with the absence of amastigotes (P less than or equal to 0.001) and the presence of giant (P = 0.03) and epitheloid cells (P = 0.03) in the biopsy of the active lesion. The presence of amastigotes was inversely related to the duration of the lesion (P less than or equal to 0.001) and the presence of eosinophils (P less than or equal to 0.01), whereas the presence of adenopathy (P = 0.01), necrosis (P = 0.001), histiocytes (P = 0.001), and increased serum antibody titer (P = 0.02) were directly associated with the presence of amastigotes. The lymphocyte transformation response was correlated with the presence of granulomas (P = 0.001), but showed no correlation with cutaneous delayed type hypersensitivity. The presence of epithelioid (P = 0.04) and giant cells (P = 0.03) was associated with less drug being required to achieve healing. In contrast, necrosis was associated with a greater amount of drug to achieve healing (P = 0.05). The observed correlations between tissue responses and immune and clinical parameters provide further evidence for the role of antibody and other soluble mediators of the cellular immune response in the evolution of disease.(ABSTRACT TRUNCATED AT 250 WORDS)
Leishmaniasis should be considered in the differential diagnosis of individuals living in or with a history of having traveled to known endemic areas and who present with signs and symptoms of visceral infection or with cutaneous or mucosal lesions. Because leishmaniae are capable of producing a wide spectrum of disease in humans, the clinical manifestations overlap with many other diseases. Definitive diagnosis of Leishmania infection in the laboratory requires demonstration of the parasite in smears, in biopsies, or by isolation of the organism in culture media or in experimental animals. Many other methods for demonstration of parasites (histochemical and immunohistochemical) or for detecting the presence of antibodies against leishmaniae (serologic) have been described. Many advances have been made in these areas, but the methodology and the technology involved in immunohistochemistry and serology remain outside the reach of the standard clinical diagnostic laboratory, which both in developed and less developed countries still relies on demonstration of the parasites in smears stained with Giemsa stain and on biopsy specimens processed and stained with hematoxylin and eosin stain. The newer serologic techniques, such as ELISA with several variations, IFAT, and others, are largely research tools with the greatest use in seroepidemiologic surveys.
A nematode larva undistinguishable from Dioctophyme renale was found in the subcutaneous tissues of the abdomen of a 23-year-old woman from Ohio. This is the third case of Dioctophyme larva reported in humans. Although it is not known how the infection was acquired, we suggest that ingestion of raw fish was the probable source. We further hypothesize that such a larva could eventually migrate to the kidney and grow to the adult state.
Some basic biologic aspects of Pneumocystis are reviewed. From the available data, it is evident that only two stages, the trophozoite and the cyst, have been described, but that the complete life cycle is unknown. Both of these two stages are found in the alveoli and other tissues of hosts with some forms of immune suppression, but rarely in healthy ones. The current views of how trophozoites evolve into cysts is outlined. No agreement about the classification of Pneumocystis has been reached, and its protozoan or fungal nature has not been fully confirmed. Recent data obtained with electron microscopy, and biochemical and molecular biologic studies, indicate that Pneumocystis has characteristics more akin to a fungus than to a protozoan. Moreover, the existence of one or of several species of Pneumocystis has not been determined. The mode of transmission of the parasite in nature, between different hosts, remains unconfirmed, although the cyst is believed to play a role.
We removed a trematode of the species Philophthalmus from under the left upper eyelid of a 66-year-old man who had follicular conjunctivitis for three weeks. After removal of the parasite, the conjunctivitis resolved.
The dysgonic fermenter-2 bacterium is a newly recognized fastidious gram-negative bacillus that causes bacteremia and sometimes endocarditis in immunocompromised persons after they are bitten by dogs. To develop an experimental model of this infection, we placed polyethylene catheters across the aortic valves of New Zealand white rabbits, which were inoculated intravenously the next day with dysgonic fermenter-2 bacteria. After 1 week, the rabbits were killed and the endocardial vegetations were homogenized for quantitative culture. Large inocula (1.3 X 10(10) to 2.1 X 10(10) viable bacteria) were required to produce infected vegetations. All infected rabbits had negative blood cultures at the time of autopsy and most developed serum agglutinins against dysgonic fermenter-2 bacteria. Three daily injections of methylprednisolone (30 mg/kg), starting the day before inoculation, significantly increased the incidence of endocarditis and the number of bacteria per gram of infected vegetation (P less than 0.05). Treatment with methylprednisolone prolonged the initial bacteremia and caused significant increases in the numbers of bacteria per gram of blood, spleen, and liver compared with those of untreated controls (P less than 0.05). Rabbits that had previously undergone splenectomy showed prolongation of the initial bacteremia but no significant increase in the incidence of infected vegetations. These results showed that the dysgonic fermenter-2 bacterium is a pathogen that causes endocarditis in rabbits but that it requires a large inoculum and produces blood culture-negative infections. Treatment with methylprednisolone enhances infection by prolonging the initial bacteremia and probably by diminishing bactericidal activity in the vegetations.
The diagnostic features in tissue sections from patients with zoonotic filarial infections are reviewed. In general, two types of infections are recognized: 1) those presenting radiologically in healthy patients as coin lesions, which are usually removed because a clinical diagnosis of carcinoma of the lung is made and infarcts containing Dirofilaria immitis parasites in pulmonary arteries are found; and 2) those presenting as subcutaneous nodules, in which D. tenuis, a parasite from raccoons, D. repens, from dogs and cats, D. ursi , from bears, and Onchocerca spp, from horses or cattle, require delineation. Moreover, nodules that on microscopic examination are seen to be lymph nodes may harbor Brugia spp. The geographic distribution of these infections, with emphasis on the United States, is discussed.