Extracellular pH in the brain during ischemia: relationship to the severity of lactic acidosis

On the basis of data showing a bimodal distribution of values for extracellular pH (pHe), and a discontinuous delta PCO2/delta lactate relationship, Kraig et al. (1986) proposed that H+ is grossly compartmentalized between neurons and glia in the ischemic brain. We measured delta pHe during ischemia, varying ischemic lactate contents between 9 and 38 mmol kg-1. No bimodal distribution was found, but delta pHe varied linearly with lactate content. Because we have also failed to record a discontinuous delta PCO2/delta lactate relationship, we conclude that major compartmentation of H+ does not occur during ischemia.     

The action of trypsin and zymosan on the respiration of cultivated endothelial cells

Trypsin and Zymosan induce an increase in respiration activity of cultivated endothelial cells. These effects are not due to the production of oxygen radicals. The effect of trypsin will be explained by interfering with the cellular homeostasis of calcium. The stimulated respiration after incubation with zymosan may be connected with the increased phagocytosis.     

32nd Annual Meeting of the Scandinavian Society for Psychopharmacology Copenhagen,Denmark April 10–12, 1991 Abstracts

32nd Annual Meeting of the Scandinavian Society for Psychopharmacology Copenhagen, Denmark April 10–12, 1991 Abstracts     

Electron microscopic immunocytochemical evidence for the existence of bidirectional synaptic connections between growth hormone-releasing hormone- and somatostatin-containing neurons in the hypothalamus of the rat

Synaptic contacts between growth hormone-releasing hormone (GHRH)- and somatostatin-containing neurons were demonstrated in the rat hypothalamus by a double-staining immunocytochemical method at the electron microscopic level. Somatostatin-immunoreactive nerve terminals synapse on GHRH-positive dendrites and cell bodies in the arcuate nucleus. A fine network of GHRH-immunopositive nerve terminals was observed at the light microscopic level in the rostral part of the periventricular nucleus and in the dorsal part of the arcuate nucleus around somatostatin-containing neuronal elements. With the electron microscope synaptic contact between GHRH-containing nerve terminals and somatostatin-containing dendrites are demonstrated. The reciprocal innervation between GHRH- and somatostatin-containing neurons that project to the median eminence and regulate growth hormone secretion must allow them to coordinate their activities.     

Enhanced take of spontaneous murine tumors in mice treated with inhibitors of macrophage and/or NK cell function

Both macrophages and NK cells have been suggested to play a role in recognizing and eliminating early, in situ neoplasms. Therefore we studied the effect of inhibitors of macrophage and/or NK cell function on the take of transplantable spontaneous murine tumors in syngeneic mice. The treatment of animals with trypan blue, a selective inhibitor of macrophage function, decreased considerably the period of latency of BSP3 adenocarcinoma; however, it did not increase the take of SP4, SP82 and SP84 adenocarcinomas. The treatment of recipients with neutral red, a selective inhibitor of NK cell function, enhanced the take of SP4 adenocarcinoma. The treatment of mice with agents depressing both macrophage and NK cell function (silica or carrageenan) decreased the both macrophage and NK cell function (silica or carrageenan) decreased the period of latency and/or increased the take of SP4, SP82 and SP84 adenocarcinomas. Carrageenan or a combined treatment with both trypan blue and neutral red also enhanced the take of BaF1, a benzo(a)pyrene-induced fibrosarcoma. We concluded that both macrophages and NK cells may function as effector cells of an antitumoral surveillance system.     

Morphological findings during retinal development and maturation in hereditary rod-cone degeneration in Abyssinian cats

The sequence of structural changes involved in postnatal photoreceptor differentiation, maturation and early degeneration was studied in young Abyssinian cats and kittens with hereditary rod-cone degeneration and compared to maturation in normal controls. In affected cats the earliest change seen was disorientation of outer segment discs in the majority of the rods, while other rods appeared to develop and mature normally. Such disorientation of discs (at oblique angles or parallel to the longitudinal axis of the outer segment, or whorls of discs) is considered as 'immaturity', since controls also showed a substantial number of disoriented rod outer segment discs at this young age. At postnatal day 35 the difference between affected animals and controls was marked with a high frequency of immature appearing rod outer segment discs in affected animals, while all rod outer segment discs were adult-like and arranged in an orderly manner in controls. Cones seemed unaffected at this age. More severe changes in affected rod outer segments in the form of disintegration of discs (vacuolization and clumping of disc material, or formation of debris), which we consider to represent degeneration, were first observed at the time when retinal maturation normally occurs in the cat, i.e. 150 days postnatally. Subsequently a drop-out of rods was seen, primarily of rods with disoriented and disintegrated outer segment discs, followed by a slow, progressive degeneration of rods that had developed and matured normally. Cones appeared normal during the time of retinal development and maturation and it was not until the age of 2-3 years (Narfstr?m and Nilsson, 1986, Incest. Ophthalmol, Vis. Sci. 27, 1569-76) that degenerative changes were seen also in cones.     

Pemphigus erythematosus--detection of anti-DNA antibodies

In an 80-year-old woman with pemphigus erythematosus, we demonstrated ANA as well as anti-DNA antibodies in the serum. This finding supports the argument that this skin disorder represents a combination of a disease of the pemphigus group with systemic lupus erythematosus.     

Cellular infiltrates in the target organs associated with acute graft-versus-host disease

Acute graft-versus-host disease (AGVHD) has been one of the major obstacles in successful bone marrow transplantation for many years. The histologic manifestations of AGVHD have been well defined but much less is known about the cellular infiltrates in the target organs during AGVHD, the structure of the inflammation is different in different target organs and is not necessarily similar to classical allograft rejection. This review covers, in addition to the histologic approach, the cytologic and functional approaches to the AGVHD associated with inflammatory cells.