RESUMO
Tolerance to extreme temperatures, thermal limits, and the mechanisms of thermoregulation are related to internal functions of insects and partly define their ecological niche. We study the association between daily activity of dung beetles from the Monte Desert in Argentina and their tolerance to high temperatures. Results indicate that for all three sympatric species studied, Eucranium belenae Ocampo, Anomiopsoides cavifrons (Burmeister), and Anomiopsoides fedemariai Ocampo, daily activity is associated to ground temperature. Eucranium belenae is active when ground temperature is relatively low and it is less tolerant to long periods of activity at high temperatures in the lab, while A. cavifrons and A. fedemariai are active when ground temperatures are higher, and they tolerate high temperatures for longer periods of time than E. belenae in the lab. These species coexist and use similar food sources, and this eco-physiological study may help to explain how they differentiate under the same environmental conditions. The Monte Desert is considered an extreme environment, and studies on thermal tolerance offer testable predictions to understand how species would respond to climate change.
Assuntos
Comportamento Animal , Besouros/fisiologia , Clima Desértico , Simpatria , Temperatura , Animais , Argentina , EcossistemaAssuntos
Gnathostoma/isolamento & purificação , Gnathostoma/ultraestrutura , Pescoço , Dermatopatias Parasitárias/diagnóstico , Dermatopatias Parasitárias/parasitologia , Infecções por Spirurida/diagnóstico , Infecções por Spirurida/parasitologia , Adulto , Animais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , México , Dermatopatias Parasitárias/patologia , Infecções por Spirurida/patologiaRESUMO
An 11-year-old girl presented from Villa Azueta, Veracruz, a poor and small town on the Tesechoacan riverside. The Tesechoacan riverside is a tropical area in the south-east of Mexico, between 18 degrees, 04',32" latitude and 95 degrees, 42',23" longitude. Her family consisted of both parents and 12 brothers, all apparently healthy and living in a humble hut, with poor nutrition and hygiene. The main sign was a tumor on her neck that had developed during the previous 6 months. On clinical examination, the patient's temperature was normal and her weight was 27.5 kg. Below the right angle of the jaw a firm-to-hard tumor was noted measuring 5 x 3 cm, it was tender and lobulated (Fig. 1) with a central purulent fistula containing small worms with morphology of Lagochilascans minor (Fig. 2). Iron-deficiency anemia was found with no increase of blood eosinophils and a while blood count of 9000/mm3 with 72% of neutrophils. Roentgenograms of the head and chest were both normal. A stool was negative for parasites; glutamic oxalade and glutamic pyruvate transaminases were normal. Histopathologic examination revealed parakeratosis and mild acanthosis with exocytosis of eosinophils. The superficial dermis showed an inflammatory reaction, mainly composed of eosinophils, plasma cells, and histiocytes, and in the deep dermis an abscess containing different sections of the parasite was seen surrounded by a thin fibrous capsule (Fig. 3). There was no clinical improvement after medical treatment with two courses of thiabendazole (50 mg/kg orally, two 5-day pulses) and praziquantel (400 mg orally for 3 days). Therefore, the growth was extirpated under general anesthesia; however, the clinical condition of the patient did not improve. Eggs, larvae, and adult worms continued to be present in the pus after surgical excision. Finally, the patient asked for a discharge and did not return to the institute.
Assuntos
Infecções por Ascaridida , Ascaridoidea , Animais , Infecções por Ascaridida/diagnóstico , Infecções por Ascaridida/parasitologia , Infecções por Ascaridida/cirurgia , Criança , Feminino , Humanos , Larva , Pescoço/parasitologiaRESUMO
BACKGROUND: Pityriasis alba is a common dermatitis, but only a few histologic studies have been reported and most of these maintain that its microscopic features are those of a chronic nonspecific dermatitis. METHODS: A retrospective light microscopic study was performed on biopsy specimens taken from 39 patients with localized pityriasis alba on face, arms and forearms without signs of atopy. Thirty-two patients were girls or women and seven were boys or men, with ages ranging from 7 to 37 years. The duration of illness varied from 1 month to 10 years. The clinical picture was characterized by three clinical stages: papular erythematous, papular hypochromic, and smooth hypochromic. RESULTS: The histologic study revealed features that were suggestive, though not pathognomonic, of the diagnosis. The most remarkable changes involved the pilary apparatus, which showed horny plugs, spongiotic edema, and atrophic sebaceous glands. There was also a disturbance of melanization secondary to epithelial damage. The tissue reaction was more conspicuous in the skin lesions with follicular papules. CONCLUSIONS: A histopathologic diagnosis of pityriasis alba may be proposed when the following features are seen in a biopsy specimen taken from a skin lesion with follicular papules: (1) irregular pigmentation by melanin of the basal layer; (2) follicular plugging; (3) follicular spongiosis; and (4) atrophic sebaceous glands.