Net transport of inorganic phosphate occurs in the absence of an electrochemical gradient from the mucosal to the serosal bathing solution in the isolated toad urinary bladder. This transport can be inhibited by metabolic inhibitors. The magnitude of this transport can be altered by changes in phosphate concentration or by the addition of parathyroid hormone.

Animals↗

PubMed1977

Extramammary Paget's disease of the vulva. A clinicopathologic study of 13 cases.

The clinicopathologic findings of 13 patients having extramammary Paget's disease of the vulva are discussed with emphasis on its histogenesis and biological behavior. For the purpose of study and assessment of prognosis, these cases were divided into two groups, those with an underlying invasive cutaneous adnexal adenocarcinoma, and those lacking an underlying invasive lesion. Four cases contained invasive cutaneous adnexal adenocarcinoma; in one of these the invasion was superficial. Three of the cases with an invasive lesion and three other cases showed in situ adenocarcinoma of sweat glands. Surgical treatment is mandatory for both groups of patients. The prognosis was excellent for the patients having Paget's disease without an underlying invasive carcinoma. From the literature, the prognosis of those with an underlying invasive carcinoma of the vulva appears to be less favorable. Multiple surgical excisions may be required to control the recurrences and metastases. A frequent association with other internal malignancy was observed. In four cases, second malignancies were found. Of special interest was the demonstration in one case of columns of neoplastic cells extending from involved sweat glands to the surface epithelium via the intradermal sweat duct. Our study leads us to support the concept that the Paget's cells, in a number of cases, are derived from an underlying carcinoma in situ of sweat gland origin.

Adenocarcinoma↗

PubMed1977

Subacute sclerosing panencephalitis.

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Adolescent↗

PubMed1975

The pulvinar nucleus of Galago senegalensis.

The present study was undertaken to analyze the connections of the pulvinar nucleus in a prosimian. The experiments, which rely on the Fink-Heimer ('67) method for staining degenerating axons and their terminals, fall into two parts: first, the tracing of ascending tectal projections to the caudal thalamus and second, the tracing of projections from this thalamic target to the cortex. Large lesions of the superior colliculus resulted in dense degeneration in the caudal half of the inferior subdivision of the pulvinar complex. This pathway could be identified when the lesion was restricted to the superficial layers of the superior colliculus, signifying that it is a visual pathway. In general, the projections of the deep and superficial layers of the superior colliculus were distinct and in this respect Galago resembles Tupaia. The inferior pulvinar nucleus in turn projects to area MT, a conspicuous subdivision of the temporal cortex. The superior division of the pulvinar, in contrast to the inferior division, is not a major target of ascending projections from the superior colliculus and projects to the areas of the occipital and temporal lobe intercalated between areas MT and 17. When these results are compared with similar studies in nonprimates, notably studies of Tupaia, a striking difference in organization emerges. In Tupaia, and in distantly related mammals such as the squirrel, the target of the tecto-pulvinar system includes area 18 adjacent to area 17. This feature is important since the two parallel projection systems seem to be related to each other in terms of the way in which the zero vertical meridian is spatially represented. However, in Galago the subdivision of the pulvinar receiving projections arising from the superior colliculus does not project to area 18. Area 18 is indeed the target of pulvinar projections, but these projections arise from that portion of the pulvinar which is not a recipient of ascending tectal projections. It is not easy to see how this primate organization, if indeed the Galago is representative of primates, evolved from the organization reflected in Tupais.

Animals↗

PubMed1975

Form preferences in successive discrimination learning of young chicks.

In four experiments the effects of form and orientation pecking preferences of 1- and 3-day old Vantress X Arbor Acre chicks on successive discrimination learning were determined, using heat reinforcement. Major findings were as follows: (a) The young chick has both circle and verticle orientation pecking preferences that are present during at least the first 3 days after hatching; (b) when either of these preferred cues is the nonreinforced cue, the young chick has difficulty in learning not to respond to it but learns quickly not to respond to an unpreferred cue (e.g., triangle and horizontal oriented dots or bar); and (c) these pecking preferences can be modified by heat reinforcement, and the effects of this conditioning is evidenct in subsequent extinction and retention tests. The main conclusion from these experiments is that form and orientation preferences, like brightness and color preferences, are important developmental constraints on conditioning of the young chick.

Age Factors↗

PubMed1975