Absence of arterial hypertension despite chronic plasma noradrenaline elevation: evidence for down-regulation of α-adrenoceptors. A case report

A 44 year old-healthy female presented chronic and stable high levels of plasma noradrenaline (NA) without any major change in adrenaline. The diagnosis of phaeochromocytoma was discarded. These increased levels of NA offered an unique opportunity to investigate under in vivo conditions a putative regulation of alpha-adrenoceptors by this endogenous catecholamine. Infusion rates of exogenous NA up to 0.74 micrograms/kg per min were unable to induce any change in blood pressure (or heart rate) in the subject, In contrast, in normotensive controls, an increase in blood pressure (+ 15 mm Hg) was observed with 0.39 micrograms/kg per min. The magnitude of yohimbine-induced increase in plasma NA was similar in the subject and in the controls. Platelet alpha 2-adrenoceptors evaluated by specific [3H]-yohimbine binding showed a significantly lower level in the subject when compared to controls. The results show that a sustained increase in plasma NA is able to induce down-regulation of alpha-adrenoceptors. This down-regulation can explain the lack of arterial hypertension despite the increased sympathetic tone.     

Hydrocephalus in the patient with acoustic neuroma.

Hydrocephalus can occur in conjunction with large acoustic neuromas. Cerebral tentorial herniation and brainstem compression can be a complication of surgical excision. Three cases of hydrocephalus and acoustic neuroma are presented and therapeutic options are discussed. Ventriculoperitoneal shunting 1 to 2 weeks before translabyrinthine or suboccipital excision of acoustic neuroma is recommended.     

A modified feather pulp culture method for determining the genetic susceptibility of adult chickens to leukosis-sarcoma viruses

A modified method is described for identifying genetic susceptibility or resistance of adult chickens to infection by avian leukosis-sarcoma viruses, by culture of feather pulp cells in micro wells coated with extracellular matrix, infection with Rous sarcoma virus, and assay for virus growth using an enzyme-linked immunosorbent assay.     

A strategy for management of upper tract calculus disease

Extracorporeal shockwave lithotripsy, percutaneous nephrolithotomy and ureterorenoscopy now mean that approximately 98% of all renal and 85% of all ureteric calculi can be treated effectively, without recourse to open operative intervention, in centres possessing the necessary equipment and expertise. Experience with these techniques allows us to propose a strategy for the surgical treatment of upper tract stone disease.     

Cellular and genetic properties of two melanoma cell lines established from the same tumor

We report here the detailed cellular and genetic analysis of two new human melanoma cell lines established from the same tumor biopsy. Although derived from the same tumor biopsy, the two lines differed in their method of in vitro culture establishment with one line (HA-A) grown first in agar culture and then transferred to liquid culture, while the second cell line (HA-L) was established directly from cells grown in liquid culture. Detailed characterization of both cell lines was performed using techniques to analyze their cytogenetic, surface marker, morphology (light and electron microscopy), growth (in agar and in nude mice), and drug sensitivity profiles in comparison to the original tumor biopsy. Our results revealed no significant biologic or genetic difference between the two cell lines established by different culture techniques. Our results suggest that in some cases agar culture prior to liquid culture may be useful in establishment of human tumor cell lines.     

Health: a basic concept in nursing theory

The concept of health is evolving over time. Traditional paradigms of health, with disease being the central focus, have emerged into complex, multidimensional models centering on a positive, holistic approach towards the phenomenon of health. The subsequent emphasis on health promotion has concomitantly affected the concept of nursing. The concept of health is a basic building block for nursing theory. How health is defined dictates how nurses should be educated and how they should practice. Incorporating the self-care model of nursing practice, health is conceived of as the effective functioning of self-care resources which ensure the operation and adequacy of self-care actions.     

Carbonic anhydrase I is an early specific marker of normal human erythroid differentiation

The expression of carbonic anhydrase (CA) as a marker of erythroid differentiation was investigated by immunologic and enzymatic procedures. A polyclonal anti-CA antibody was obtained by immunizing rabbits with purified CA I isozyme. This antibody is reactive with CA I but not with CA II. Within blood cells, CA I was only present in erythrocytes, whereas CA II was also detected in platelet lysates by enzymatic assay. Concerning marrow cells, identifiable erythroblasts and some blast cells expressed CA I. Most of the glycophorin A-positive marrow cells were clearly labeled by the anti-CA I antibody. However, rare CA I-positive cells were not reactive with anti-glycophorin A antibodies. We therefore investigated whether these cells were erythroid precursors or progenitors. In cell sorting experiments of marrow cells with the FA6 152 monoclonal antibody, which among hematopoietic progenitors is reactive only with CFU-E and a part of BFU- E, was performed, CA I+ cells were found mainly in the positive fraction. The percentage of CA I+ cells nonreactive with anti- glycophorin A antibodies contained in the two fractions was in the same range as the percentage of erythroid progenitors identified by their capacity to form colonies. In addition, the anti-CA I antibody labeled blood BFU-E-derived colonies as early as day 6 of culture, whereas in similar experiments with the anti-glycophorin A antibodies, they were stained three or four days later. No labeling was observed in CFU-GM- or CFU-MK-derived colonies. The phenotype of the day 6 cells expressing CA I was similar to that of erythroid progenitors (CFU-E or BFU-E): negative for glycophorin A and hemoglobin, and positive for HLA-DR antigen, the antigen identified by FA6 152, and blood group A antigen. Among the cell lines tested, only HEL cells expressed CA I, while K562 was unlabeled by the anti-CA I antibody. In contrast, HEL and K562 cells expressed CA II as detected by a biochemical technique. Synthesis of CA I, as with other erythroid markers such as glycophorin A and hemoglobin, was almost abolished after 12-O-tetradecanoyl-phorbol-13 acetate treatment of HEL cells. In conclusion, CA I appears to be an early specific marker of the erythroid differentiation, expressed by a cell with a similar phenotype as an erythroid progenitor.