Cytogenetic and molecular genetic analysis of tumorigenic human bronchial epithelial cells induced by radon alpha particles

To establish a cell culture model for lung carcinogenesis, independent populations of the human papillomavirus 18-immortalized human bronchial epithelial cell line BEP2D were treated with high linear energy transfer radon-simulated alpha-particles, expanded and xenotransplanted into Nu/Nu mice. Six independent cell lines were established from tumors that developed from three separate radiation treatments as follows: treatment (Tx) 1 (30 cGy--two doses), H2BT, Tx 2 (30 cGy-- single dose), R30T1L, R30T2 and R30T3L, Tx 3 (30 cGy--single dose), H1ATN and H1ATBA1. Cytogenetic analysis revealed common changes in all tumor lines: loss of the Y chromosome (ch), one of three copies of ch8, one of three copies of ch14, and one of two copies of ch4p16-pter and ch11p15-pter. Analysis of polymerase chain reaction-amplified short tandem repeats of informative loci confirmed the loss of chY in all lines and loss of heterozygosity (LOH) at eight loci spanning the length of ch8 in all lines from Tx's 1 and 2. Our data support previous studies indicating the presence of tumor suppressor genes on ch8. LOH also was confirmed on ch14 at locus D14S306 in all cell lines from Tx 2 and in one of two lines from Tx 3. This region, 14q12-q13, may contain changes in one of the five known somatostatin receptor genes (SSTR1). No LOH was detected at any of the informative loci tested for on ch4 or ch11.      

Simple and complex antibody reactions in radioimmunoassay and the prediction of assay characteristics

Radioimmunoassays are usually developed empirically since there have been few established rules which cover general RIA behaviour. Evidence is presented which enables the delineation of 2 types of RIA with distinct group characteristics. (1) Simple RIA, conforming to the law of mass-action kinetics, is a result of univalent interaction. Examples of simple RIA include hapten assays and those using a monoclonal antibody (McAb). (2) Complex RIA occurs when antigen reacts multivalently with a polyclonal antiserum (PcAs). The formation of multicomponent complexes between a large molecular weight antigen and a PcAs is demonstrated using gel exclusion chromatography. These complexes are resistant to dissociation and are responsible for higher affinity, greater sensitivity and slower equilibration times compared to simple RIA. The assignment of an assay to either the simple or complex RIA group is dependent upon either the molecular size of the antigen or the use of a McAb. The consequent predictability of RIA behaviour enables a more rational approach to optimal assay design than current theory allows. It is advocated that the inability of a McAb to form multicomponent complexes is a major disincentive to their indiscriminate adoption in RIA.     

Central muscle relaxant properties of 2,6-dimethylphenethylurea and related compounds

Twenty-eight phenylalkylureas with alkyl, hydroxy, methoxy or chloro-substituents in the aryl ring have been synthesized and tested for central depressant and muscle relaxant properties. In this series, the dimethylphenethylureas with at least one ortho-methyl group show unexpectedly selective muscle relaxant activity. 2,6-Dimethylphenethylurea inhibits polysynaptic reflexes more readily than monosynaptic ones, but also depresses muscle contractions by an action independent of its effect on interneuronal transmission. It is a weak anticonvulsant, suppresses rage episodes in “fighting” mice, and has no selective blocking action on conditioned responses. It thus has a pharmacological profile resembling those of mephenesin and meprobamate, but distinct from either, and differing still more from those of phenobarbitone, chlordiazepoxide or chlorpromazine. However, tolerance to its action develops readily.     

Further studies of rimiterol and salbutamol administered by intermittent positive-pressure ventilation, and an important observation on the technique of using the Bennett ventilator.

1. Using the same technique of administering drugs by intermittent positive-pressure ventilation as used in previous studies a source of contamination of solutions nebulized was discovered. This was rectified by using a new ventilator and completely separate patient circuits for each solution nebulized. 2 Salbutamol 0.5% and 0.25% solutions achieved the same degree of bronchodilatation, but there was a significantly greater increase in heart rate produced by salbutamol 0.5%. 3 Rimiterol 0.5% and salbutamol 0.25% produced similar peak mean improvements in FEV and also induced the same degree of tachycardia, but the duration of these effects were significantly shorter in the case of rimiterol. 4 The sustained degree of bronchodilatation achieved by salbutamol 0.25% could not be mirrored by giving two doses of rimiterol 0.5%, the second dose 2 h after the first. 5 Rimiterol 0.5% induced a degree of tachycardia which was similar in peak effect to that observed after salbutamol 0.25%. However, in the controls the second dose of rimiterol, given 2 h after the first, was responsible for only a small increase in heart rate which was not significantly different than that after saline in the other three treatment groups.     

Effect of chronic renal failure on cardiac contractile function,calcium cycling,and gene expression of proteins important for calcium homeostasis in the rat

Patients with chronic renal failure frequently develop cardiac hypertrophy and diastolic dysfunction; however, the mechanisms by which this occurs are still unclear. Male Sprague-Dawley rats were subjected to 5/6 nephrectomy and studied for their isolated myocyte function, calcium cycling, and gene expression of proteins important in calcium homeostasis after 4 wk. Comparable rats subjected to suprarenal aortic banding for the same duration were used for comparison. Rats subjected to 5/6 nephrectomy and aortic banding developed comparable hypertension; however, rats subjected to 5/6 nephrectomy experienced a greater degree of cardiac hypertrophy and downregulation of cardiac sodium potassium ATPase (Na+/K+ -ATPase) activity than rats subjected to aortic banding. Moreover, cells isolated from the 5/6 nephrectomy rat hearts displayed impaired contractile function and altered calcium cycling compared with cells isolated from control or aortic constriction rat hearts. The 5/6 nephrectomy rat heart cells displayed a prolonged time constant for calcium recovery following stimulation, which corresponded to decreases in homogenate sarcoplasmic reticulum calcium ATPase-2a (SERCA2a) activity, protein density, and mRNA for SERCA2a. In conclusion, chronic renal failure leads to alterations in cardiac gene expression, which produces alterations in cardiac calcium cycling and contractile function. These changes cannot be explained only by the observed increases in BP.     

The effect of donepezil on sedation and other symptoms in patients receiving opioids for cancer pain: a pilot study

Opioid-induced sedation is a major complication in patients with cancer pain. This study assessed the effectiveness of donepezil in opioid-induced sedation and related symptoms in patients with cancer pain. Twenty-seven patients who were receiving strong opioids for pain and reported sedation were enrolled. Donepezil 5 mg was given every morning for 7 days. Changes between baseline and Day 7 in sedation, pain, fatigue and other symptoms were evaluated using the Edmonton Symptom Assessment Scale. Fatigue was also measured using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue). Overall usefulness of donepezil was measured by the patient at the end of the study. In 20 evaluable patients, sedation, fatigue, anxiety, well-being, depression, anorexia and problems with sleep were significantly improved. Side effects included nausea, vomiting, diarrhea, muscle and abdominal cramps, and anorexia. Overall, however, the treatment was well tolerated. Donepezil appears to improve sedation and fatigue in patients receiving opioids for cancer pain. Randomized controlled trials of this agent are justified.