The pA2 values for naloxone-morphine were determined using ilea taken from naive and morphine-tolerant guinea-pigs. This constant decreased from 8.56 (+/- 0.22) in the naive to 7.95 (+/- 0.12) in tolerant tissues. The values of the pA2's were based on Schild plots using conventional regression techniques; this regression resulted in values of -log KB of 8.79 (+/- 1.5) and 8.18 (+/- 1.2) in naive and morphine-tolerant ilea, respectively. While pA2 differed, the difference in -log KB was not statistically significant. Since these two values are theoretically equivalent, the above finding appears paradoxical. Constraining the slope of the Schild plot to the theoretically required -1 resolved this discrepancy by reducing the error inherent in the calculation of -log KB determined by conventional regression.

Animals↗

PubMedDate not supplied

The effects of histones, in vitro age, and culture state on the digestion of DNA by micrococcal nuclease and deoxyribonuclease I.

Nuclei from confluent and mitotically arrested populations of human diploid fibroblast-like cells were subjected to digestion by micrococcal nuclease and deoxyribonuclease (DNase I) following the removal of various histone components by salt extraction. There was no age or culture state variation in the susceptibility of DNA to micrococcal nuclease digestion. There was an age related inhibition of DNA digestion by DNase I in nuclei from older confluent cells before and after the removal of H1 histone but not after the removal of core particle histones. This inhibition was not detected in older arrested populations. These results indicate that an age-related masking by nucleosome core histones may limit the accessibility of DNA to enzymatic activities in older confluent cells. Since this inhibition was absent in older arrested populations, the importance of limited DNA accessibility as a primary cause of cellular senescence is questionable.

Cell Survival↗

PubMedDate not supplied

Inflammatory fibroid polyp of the small intestine: ultrastructural and immunohistochemical observations.

The ultrastructural and immunohistochemical features of a primary tumor of the ileum showing the classic histologic features of an inflammatory fibroid polyp (IFP) of the gastrointestinal tract are presented. Ultrastructurally the proliferating cells showed a combination of fibroblastic and histiocytic features, with abundant rough endoplasmic reticulum and active production of collagen in many of the cells and long, dendritic cytoplasmic projections with large cytoplasmic vacuoles containing remnants of phagocytosed cellular debris in others. Immunohistochemical studies showed strong cytoplasmic positivity in the proliferating cells with vimentin antibodies and scattered positivity with muramidase. Additional findings include the ultrastructural demonstration of oligocilia and occasional primitive intercellular junctions. The findings in this case suggest that IFP may represent a proliferation of primitive submucosal stromal cells exhibiting incomplete fibrohistiocytic differentiation.

Aged↗

PubMedDate not supplied

Childhood malaria in Britain.

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Child↗

PubMedDate not supplied

Automated sonomammographic-xeromammographic-pathologic correlations in the assessment of carcinoma of the breast.

Automated sonomammography and xeromammography were compared in a group of 293 patients referred for a variety of symptomatic and asymptomatic conditions. Twenty of the 293 patients had mammographic evidence of carcinoma that was confirmed pathologically. Seventeen of these patients had sonomammographic evidence of a solid mass; 11 of these demonstrated signs of malignancy, such as irregular border, and desmoplastic reaction manifested by thickening of Cooper's ligaments, skin retraction, periductal fibrosis or disruption of architecture. Statistical analysis of the results reveals that a high degree of sensitivity and specificity in the diagnosis of malignant breast disease can be accomplished with automated sonomammography.

Adult↗

PubMedDate not supplied

Placental intravillous accumulation of sulfated mucosubstances. A reevaluation of so-called hydropic degeneration of villi.

A histochemical study was performed on 46 placentas showing so-called hydropic degeneration of villi. The 46 cases included early abortuses (35 cases), incomplete moles (four cases), and complete hydatidiform moles (seven cases). All the specimens showed diffuse, positive staining of the distended villous stroma with alcian blue at pH 1.2 and 2.5 in the areas containing "hydropic changes." The alcian blue positivity was abolished following digestion with hyaluronidase. These findings indicate that so-called "hydropic degeneration of villi" represents an intravillous accumulation of strongly sulfated mucosubstances rather than the result of the accumulation of water. The intravillous accumulation of mucosubstances most likely represents a nonspecific stromal reaction of the connective tissue of the placenta to a variety of noxious stimuli. This finding may have some bearing on the interpretation of the physiologic mechanisms involved in placental villous distention, which has been largely centered in the past on the premise that the villous swelling was related to hemodynamic alterations caused by the accumulation of water.

Abortion, Spontaneous↗