α-Glucosidase inhibitory phenolics from Echeveria subrigida (B. L. Rob & Seaton) leaves.

Echeveria subrigida is native to Mexico and its methanol extract (ME) shows relevant biological activities for human health, including the α-glucosidase inhibitory (αGI) activity that suggests its antidiabetic potential. Fractionation of the ME based on the αGI activity (IC50 in µg/mL) showed that quercetin-3-O-ß-glucoside (131.1), isorhamnetin-3-O-ß-glucoside (166.4), and dimers to heptamers proanthocyanidins (9.6) were among the main responsible of αGI activity in the ME. The purified compounds showed better activity than acarbose (IC50 = 4426 µg/mL).

Association of human beta-defensin 1 gene polymorphisms with nonsegmental vitiligo.

BACKGROUND: Vitiligo is a pigmentation disorder of autoimmune aetiology. Polymorphisms in beta-defensin genes have been linked to a predisposition to some autoimmune disorders. AIM: To evaluate the role of polymorphisms in DEFB1, the gene encoding for human beta-defensin (HBD)-1 and its 5' untranslated region in nonsegmental vitiligo. METHODS: In total, 354 participants [171 patients with non-segmental vitiligo and 183 age and sex-matched healthy controls (HCs)], were genotyped by the PCR-restriction fragment length polymorphism (RFLP) method. For 80 of these individuals (40 patients and -40 HCs) serum HBD-1 was also measured by ELISA. RESULTS: The -44 G allele, CG genotype and GGG haplotype increased the risk for vitiligo (P < 0.02 in all cases), whereas the -20 AA genotype seems to be protective (P = 0.04). Serum HBD-1 levels were lower in patients with vitiligo than in HCs (P < 0.01), as well as in patients with active vitiligo compared with those with stable vitiligo and with HCs (P < 0.05 in both cases), CONCLUSION: Our results suggest that HBD-1 and its gene polymorphisms may modulate vitiligo susceptibility and/or disease activity. This is the first report, to our knowledge, of the association of serum HBD-1 levels and DEFB1 gene polymorphisms with vitiligo.

Serodiagnostic reliability of single-step enriched low-molecular weight proteins of Taenia solium metacestode of American and Asian isolates.

The low-molecular weight proteins (LMWPs) of Taenia solium metacestode (TsM) constituted pertinent serodiagnostic antigens for cysticercosis. We established a novel single-step purification of the LMWPs from TsM cyst fluid (CF). When the CF was precipitated with trichloroacetic acid/acetone mixture at the final concentrations of 5 and 50%, most LMWPs (ranging 7-38kDa) remained in the supernatant fraction. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analyses revealed that the LMWPs consisted mainly with the previously reported subunit proteins of the 120- and 150-kDa antigen complexes. Serum samples from neurocysticercosis (NC) and other helminthic infections, as well as those from healthy controls were tested by both immunoblotting and micro-ELISA. In 135 cases of active stage NC patients, 132 cases (97.7%) showed positive reactions. Serum samples from other helminthic diseases (n=125) and healthy controls (n=100) exhibited no positive reactions except for cystic echinococcosis, of which 12% (3/25 cases) exhibited low levels of cross-reactivity. The LMWPs from different geographical regions (Korea and Mexico) showed diagnostic sensitivity and specificity of 97.7% and 98.7% against active stage NC. Our single-step separation method for the LMWPs provided excellent performance with easy applicability and high reproducibility, which has a great benefit for preparation of potent antigen in endemic areas.

Trichuriasis and low-iron status in schoolchildren from Northwest Mexico.

BACKGROUND/OBJECTIVES: The aim of this study was to investigate the association between trichuriasis and iron status in rural schoolchildren from Northwest Mexico. SUBJECTS/METHODS: A total of 73 schoolchildren (37 boys, 36 girls) between the ages of 6 and 10 years were voluntarily recruited from the public primary school of the rural community of El Higueral in Culiacan, Sinaloa (Northwest Mexico) for a cross-sectional study with a longitudinal follow-up of 5 weeks. Data were collected on socioeconomic status, anthropometry, haematological and biochemical indices of iron status, daily iron intake, and prevalence and intensity of trichuriasis. Multiple regression models, independent t-test and paired t-test were used to analyse the association between trichuriasis and iron status in cross-sectional and longitudinal samples, respectively. Adjusted models were tested for linear regression assumptions using residual plots. RESULTS: The mean age of the Trichuris-free and Trichuris-infected groups was 7.7±1.3 and 7.7±1.5 years respectively (P=0.92). The height for age was significantly higher in the Trichuris-free group than the Trichuris-infected group (P=0.02). No differences were found in the socioeconomic variables between the two groups. At baseline, significantly higher concentrations of haemoglobin, haematocrit, blood cell count (RBC) and serum iron were measured in the Trichuris-free group compared with the Trichuris-infected children (P<0.05). An association was found between trichuriasis and haemoglobin adjusted for socioeconomic variables, age and sex. Haemoglobin, RBC and serum ferritin concentrations were significantly increased in the infected children 5 weeks after treatment (P<0.05). CONCLUSIONS: Trichuriasis could be a risk factor for low-iron status in the schoolchildren of Northwest Mexico.

Prevalence and intensity of intestinal parasitic infections in relation to nutritional status in Mexican schoolchildren.

Undernutrition and intestinal parasitic infections affect childhood development and morbidity in many developing countries. Undernutrition may increase susceptibility to parasitic infections which in turn impair the nutritional status of the host. The relationship between intestinal parasitic infections and nutritional status in 400 Mexican schoolchildren was investigated. More than half of the children in the study showed intestinal parasites and polyparasitism. The prevalence of helminth infections was significantly higher in Oaxaca than in Sinaloa (P < 0.05). Z scores for weight-for-age (WA) and height-for-age (HA) were much lower in children of Oaxaca than in Sinaloa (P < 0.001). A significantly higher Z score for weight-for-height (WH), WA, and HA were found in non-infected versus infected children (P < 0.05). Higher prevalences of intestinal infections were found in children with lower HA and WA than in normally nourished children (P < 0.05). Higher intensities of Ascaris lumbricoides and Trichuris trichiura were found in the schoolchildren of Sinaloa than in Oaxaca (P < 0.01). Negative and significant associations were found between Hymenolepis nana and T. trichiura infection (eggs per gram) and nutritional status. Intestinal parasitic infections may be regarded as main risk factors associated with poor nutritional status in Mexican schoolchildren.

The first human case in Mexico of conjunctivitis caused by the avian parasite, Philophthalmus lacrimosus.

Species of Philophthalmus parasitize primarily the eyes of wild and domestic birds. A variety of mammals, including humans, occasionally serve as the intermediate as well as the definitive hosts for this parasite, although human cases are extremely rare. Here, we report a case of human conjunctivitis caused by an infection with Philophthalmus sp. in Mexico. The patient was a 31-yr-old male who visited an ophthalmologist in Los Mochis, Sinaloa, Mexico, because of a foreign-body sensation in his left eye for 2 mo. A small live parasite was found in the connective tissue of the bulbar conjunctiva and was removed surgically under local anesthesia under ophthalmoscopic observation. The parasite was identified morphologically as Philophthalmus lacrimosus Braun, 1902. This is the first case of human philophthalmosis in Mexico and, to our knowledge, the first human case of P. lacrimosus infection in the world.

Short report: gnathostomiasis in Mexico.

Gnathostomiasis is an important food-borne parasitic zoonosis that is endemic mainly in Asian countries where some people prefer to eat raw freshwater fish. In North America, the first recorded case of gnathostomiasis was in Mexico in 1970, and the numbers of gnathostomiasis patients in Mexico seems to be increasing dramatically with time. However, the epidemiology of this disease in Mexico has never been described in detail. Here we review the current status of gnathostomiasis in Mexico.

Gnathostomiasis in wild boars from Japan.

Gnathostoma doloresi, a nematode parasite producing ulcerative and/or granulomatous lesions in the gastric wall of domestic pigs and wild boars (Sus scrofa leucomystax) throughout southeastern Asia, is an important zoonosis causing cutaneous larva migrans in humans. Patients infected with G. doloresi have been found yearly in the vicinity of Miyazaki Prefecture, Japan. Adult nematodes were found in 31 of 32 wild boars captured at two different geographic locations in the prefecture, a location in the high mountains and one at sea level. The parasite-free animal had gastric lesions typical of a previous infection with this parasite. The nematode intensities were higher in wild boars caught in the mountains than those caught at near sea level. The extremely high prevalence of G. doloresi in wild boars indicates that the life cycle of this parasite is well established in this area of Japan.

Clinical manifestations and immunodiagnosis of gnathostomiasis in Culiacan, Mexico.

Gnathostomiasis was first described in Mexico in 1970, and endemic areas have been spreading in six states of this country. In Culiacan, Sinaloa, 300 cases of cutaneous larva migrans were recorded between January 1992 and December 1995. In addition, a Gnathostoma larva was surgically removed from the eye of one patient. Cutaneous lesions were observed mainly on the face, neck, arms, and legs. About 70% of the patients showed eosinophilia. A skin biopsy was carried out on 35 patients and the parasite was identified in histopathologic sections of 12 of these patients. In four patients, the larva migrated out spontaneously from the skin. An enzyme-linked immunosorbent assay using a crude somatic extract of adult Gnathostoma doloresi worms showed that 93% of the patients were seropositive, confirming the reliability of clinical diagnosis. A total of 14 advanced third-stage Gnathostoma larvae were found in four species of ichthyophagous birds captured on dams and dikes near the city of Culiacan. Scanning electron micrographs of human and bird larvae showed that they were morphologically indistinguishable from G. spinigerm. We conclude that the life cycle of Gnathostoma has been established in Sinaloa, and has become a serious public health issue for residents.

Epidemiologic study and control of Taenia solium infections with praziquantel in a rural village of Mexico.

This study reports the results of an epidemiologic survey for the detection of Taenia solium in a rural village of 559 inhabitants in Sinaloa, Mexico, as well as a large scale treatment of the population with praziquantel. The study was carried out in two stages. In stage 1, serial stool analysis of 392 persons detected a cluster of three T. solium tapeworms. A fourth T. solium tapeworm was detected through a household census, giving a 1.32% prevalence rate for this helminth. Over 70% of the population over five years of age was treated with a 10 mg/kg dose of praziquantel, and no additional tapeworms were found. Environmental studies for the detection of Taenia sp. eggs in soil, water, and and objects from the houses of tapeworm-infected individuals showed only one soil sample containing eggs compatible with Taenia sp. A total of 72 domestic pigs were examined for the presence of cysticerci under the tongue. One animal had cysts, and belonged to a household that had two T. solium tapeworm infections. Stage 2 of the study was carried out one year after large scale antihelminthic treatment (LSAT), and no infections with Taenia sp. eggs were found. No cysticercus-infected pigs were detected. Intestinal parasitosis decreased from 69.2% to 37.5%. It is concluded that LSAT with praziquantel is efficient in decreasing endemic foci of T. solium. Seropositivity to T. solium bladder fluid antigens was tested by enzyme-linked immunosorbent assay and found to be 11% before LSAT and 7% one year later. In family members living with T. solium tapeworm carriers, the number of seropositive individuals was 28%. The relative risk ratio of seropositivity for persons living in the same household with a T. solium tapeworm carrier was 2.95. Positive response was significantly higher in the 30-39-year-old age group, in which 30% were seropositive in stage 1, compared with 7% one year after LSAT. High seropositivity rates were significantly associated with tapeworm clusters as well as with individuals with a clinical history of seizures.