Expression and interconversion of neuron-specific enolase in patient sera and extracts from small-cell lung cancer cells

The isoforms of gamma-enolase were characterized in serum from patients with small-cell lung cancer (SCLC) and in extracts from SCLC cell lines and malignant melanoma tumor tissue. Large variations in the expression of the 3 gamma-isoforms of enolase were observed. These forms probably represent the homodimeric gamma gamma-enolase, the heterodimeric alpha gamma-enolase and the monomeric forms of gamma-enolase. Only the dimeric forms are enzymatically active. The predominant gamma-enolase in the cell lines is the heterodimeric alpha gamma-enolase. The SCLC cell lines can be divided into two groups: one with negligible gamma gamma-enolase expression and considerable amounts of the nonneuronal alpha alpha-enolase and a second group with a large fraction of gamma gamma-enolase concomitant with a low expression of alpha-enolase. Similar patterns are observed in tissue extracts from malignant melanoma. When changing buffer conditions by increasing the ionic strength and decreasing the Mg2+ concentration, interconversions between the isozymes occur. In contrast to the predominant alpha gamma-enolase in extracts from cell lines, the multiple forms of gamma-enolase in serum might be caused by a subunit exchange facilitated by the low Mg2+ concentration in plasma. However, there seems to be a stable equilibrium between the isoforms in undiluted patient serum. The induction of subunit exchange by perturbation in ionic strength and/or Mg2+ concentration indicates a need for caution when choosing diluents for use in assays for neuron-specific enolase.     

A new technique for radiotherapy planning using quadratic programming

Previous attempts at optimization of radiotherapy planning are described and criticized, and consideration of these attempts has resulted in the development of a new technique using quadratic programming. Uniformity of tumour dose is selected as the most important feature of any plan, and this is achieved by minimizing the variance of the dose to preselected points within the tumour. The dose to vulnerable regions can be constrained not to exceed a given percentage of the mean tumour dose. Optimization of field weight and field type is possible. The operation of the system is described and some typical results are given.     

Arthritis with an inflammatory dermatosis resembling Sweet's syndrome. Report of a unique case and review of the literature on arthritis associated with the inflammatory dermatoses

A patient with a unique case of chronic episodic arthritis coincident with flares of acneform, pustular, nodular and ulcerating skin lesions was observed over a five-year period. This patient and a review of the literature on arthritis associated with the inflammatory dermatoses provide evidence which may interrelate several of these nosologically confusing skin conditions, e.g., the family of leukocytoclastic angiitides with the newly posited acute febrile neutrophilic dermatosis of Sweet. Systemic manifestations and a variety of acneform, pustular, nodular and ulcerating cutaneous lesions in the inflammatory dermatoses are best explained by small vessel involvement, with individual syndromes being determined by the type and degree of vascular change. Perivascular neutrophilic infiltration is the unifying histologic feature of these small vessel diseases. Neutrophil infiltration differentiates these entities, and our patient, from the histologically nonspecific inflammations of the skin, e.g., Behcet's disease and pyoderma gangrenosum, which, although capable of causing identically appearing skin lesions, consist predominantly of lymphocytic dermal infiltrates even in the earlier stages. It appears important to recognized these morphologically varied acute inflammatory dermatoses with perivascular neutrophilic infiltration in view of their systemic features and the dramatic efficacy of corticosteroid therapy.     

A multiaperture collimator for use at 511 keV

The addition of autologous serum to mixtures containing human red cells, from pregnant and nonpregnant females, and sheep cells resulted in the formation of mixed aggregates containing both human and sheep red cells. In contrast, no aggregate formation occurred when autologous cord serum was added to mixtures containing cord red cells and sheep red cells. Heat inactivation of the adult serum or the presence of 0.15 M EDTA prevented the formation of mixed aggregates. These observations indicated that the mixed aggregates occurred through the complement-dependent red cell immune adherence (RCIA) phenomenon. The addition of untreated cord serum to mixtures containing inactivated adult serum restored the formation of mixed aggregates, indicating that the cord serum contained sufficient complement for RCIA. Natural antibody against sheep red cells was present in adult sera but was absent in cord sera. Using the RCIA receptor assay, the RCIA receptor activity of cord red cells was found to exceed significantly that of the adult pregnant cells (p less than 0.0025). It is postulated that this may represent an aspect of immune adaptation between mother and fetus.     

Symptomless hypoglycaemia

We report an unusual case of hypoglycaemia, in which a pregnant woman with a Rh-negative problem and random blood glucose levels of less than 10 mg/100 ml was found to have no clinical symptoms of hypoglycaemia. The patient, who had a blood glucose concentration of 7 mg/100 ml, behaved as normally as a person with the expected average physiological value. This finding did not seem to be connected in any way with the patient's serious Rh-ve problem. We have been unable to find reports of a similar situation in the literature available to us.     

Amphotericin B-induced changes in K+ content, viability, and ultrastructure of yeast-phase Histoplasma capsulatum

Yeast-phase cells of Histoplasma capsulatum were challenged with amphotericin B, and membrane perturbation was monitored by K+ efflux. Suspensions of washed cells readily absorbed about 1.12 microgram of amphotericin B per mg (dry weight) and further nonspecific sites were also apparent. The dose-response curve for initial rate of K+ efflux was sigmoidal within the range 0.1 to 1.0 microgram of amphotericin B per ml. A fungistatic concentration of amphotericin B (0.3 microgram/ml) evoked an efflux of 85 to 90% K+ from the cells within 15 min, but cell viability decreased only 13% (yeast phase) or 33% (transformed to mycelial units). Ultrastructural changes in treated cells were detected within 5 min, and the hallmark was expansion of vacuoles during the 1-h monitoring period. In contradistinction to a previous report, the appearance of the protoplasmic membrane was not altered by fungistatic concentration. When treated cells were returned to a fresh growth medium, there was a pronounced lag (20 h). During this apparent recovery phase, the large vacuoles fragmented and returned to normal size. It is proposed that vacuoles of H. capsulatum act as a spatial buffer of considerable survival value to stressed cells.