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H Wheat

Publications and source records attributed to H Wheat.

5 recordsLinked to original sources
PubMed1997

Cross-reactivity in Histoplasma capsulatum variety capsulatum antigen assays of urine samples from patients with endemic mycoses.

We evaluated cross-reactivity in the antigen assay used for the diagnosis of histoplasmosis by testing urine samples from patients with disseminated fungal infections. The mycoses chosen for this study were selected on the basis of the observation that during clinical testing, cross-reactions may occur between Histoplasma capsulatum var. capsulatum, Paracoccidioides brasiliensis, Blastomyces dermatitidis, Coccidioides immitis, and Penicillium marneffei. We detected antigen in 12 of 19 patients with blastomycosis, 8 of 9 with paracoccidioidomycois, in 17 of 18 with P. marneffei infection, and in one with disseminated H. capsulatum var. duboisii infection. Cross-reactions were not observed in the assays for six patients with disseminated coccidioidomycosis. Cross-reactivity between the agents of other endemic mycoses should be considered in interpreting a positive H. capsulatum var. capsulatum antigen assay. Antigen detection may provide a rapid, provisional diagnosis for patients with serious infections caused by one of these organisms.

Antigens, Fungal↗
PubMed1996

Orientation selectivity of thalamic input to simple cells of cat visual cortex.

More than 30 years after Hubel and Wiesel first described orientation selectivity in the mammalian visual cortex, the mechanism that gives rise to this property is still controversial. Hubel and Wiesel proposed a simple model for the origin of orientation tuning, in which the circularly symmetrical receptive fields of neurons in the lateral geniculate nucleus that excite a cortical simple cell are arranged in rows. Since this model was proposed, several experiments and neuronal simulations have suggested that the connectivity between the lateral geniculate nucleus and the cortex is not well organized in an orientation-specific fashion, and that orientation tuning arises instead from extensive interactions within the cortex. To test these models we have recorded visually evoked synaptic potentials in simple cells while cooling the cortex, which largely inactivates the cortical network, but leaves geniculate synaptic input functional. We report that the orientation tuning of these potentials is almost unaffected by cooling the cortex, in agreement with Hubel and Wiesel's original proposal.

Animals↗
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Community Mental Health Centers↗