[Use of a digital radiology system with phosphors in the assessment of thoracic diseases in bedside radiography]

We report our experience with a storage phosphor radiography system; to assess both the image resolution and the dynamic range of the system, a phantom simulating chest average density was used. Finally, we investigated the system impact on portable chest radiographs. The radiographs were taken on 35 x 43 cm phosphor plates, with 80 kV, 3 mAs and focus-film distance of 130 cm. The phosphor plates were scanned with a 75 microns laser beam, postprocessed with the system software and, finally, printed on a 20 x 25 cm film. As reported by other Authors, the storage phosphor system showed similar spatial resolution to conventional radiography (2.5 lp/mm for 35 x 43 cm films and 4.5 lp/mm for 20 x 25 cm films), a wide dynamic range always allowing correcting exposure, but increased noise; these features allow film density optimization even in such "critical" situations and bedside radiographs. Pneumonia, pneumothorax, emphysema, pleural effusions and catheters or tubes positioning were always easily depicted. In our experience, the phosphor plate storage system exhibits many advantages over conventional radiography, namely image postprocessing, the opportunity to choose between several sizes of laser films and finally, the possibility of linking the system to a network and possibly to a digital archive. The main drawbacks of the system are its increased noise and, at present, with the available hardware, slow plate reading.

Conversion of recent onset atrial fibrillation with single loading oral dose of propafenone: is in-hospital admission absolutely necessary?

A population of 283 patients with recent onset (< 72 hours) AF, without heart failure, who received a single 450- or 600-mg oral dose of propafenone, or digoxin 1 mg, or placebo for conversion to sinus rhythm (SR), was studied to determine whether a routine admission to the hospital for drug administration is justified. Previous bradyarrhythmias or sick sinus syndrome (SSS), and concomitant use of antiarrhythmic drugs were exclusion criteria. None of the 283 patients studied experienced VT or VF and none of them needed implantation of a temporary pacemaker. Periods of atrial tachyarrhythmias with regularization of atrial waves and 1:1 AV conduction were observed in only two cases, both receiving placebo. No predictor of proarrhythmia was found among the clinical variables considered (age, etiology, arrhythmia duration, atrial dimension, and blood potassium). No serious hemodynamic adverse effects were noted in either group. The rates of conversion to SR after 4 hours were: 80 (57%) of 141 patients who received propafenone and 35 (25%) of 142 patients who received digoxin or placebo (P < 0.001). Acute oral treatment with propafenone is simple and effective for the conversion of recent onset AF to SR in patients without clinical signs of heart failure. The routine admission of these patients to the hospital is not necessary. Home-based administration of oral propafenone to a selected group of patients could significantly increase the cost effectiveness of this treatment.

Dominant inhibitory Ras delays Sindbis virus-induced apoptosis in neuronal cells

Mature neurons are more resistant than dividing cells or differentiating neurons to Sindbis virus-induced apoptotic death. Therefore, we hypothesized that mitogenic signal transduction pathways may influence susceptibility to Sindbis virus-induced apoptosis. Since Ras, a 21-kDa GTP-binding protein, plays an important role in cellular proliferation and neuronal differentiation, we investigated the effect of an inducible dominant inhibitory Ras on Sindbis virus-induced death of a rat pheochromocytoma cell line, PC12 cells. Dexamethasone induction of dominant inhibitory Ras (Ha Ras(Asn17)) expression in transfected PC12 cell lines (MMTV-M17-21 and GSrasDN6 cells) resulted in a marked delay in Sindbis virus-induced apoptosis, compared with infected, uninduced cells. The delay in death after Sindbis virus infection in induced versus uninduced PC12 cells was not associated with differences in viral titers or viral infectivity. No delay in Sindbis virus-induced apoptosis was observed in Ha Ras(Asn17)-transfected PC12 cells if dexamethasone induction was initiated less than 12 h before Sindbis virus infection or in wild-type PC12 cells infected with a chimeric Sindbis virus construct that expresses Ha Ras(Asn17). The delay in Sindbis virus-induced apoptosis in induced Ha Ras(Asn17)-transfected PC12 cells was associated with a decrease in cellular DNA synthesis as measured by 5'-bromo-2'-deoxyuridine incorporation. Thus, in PC12 cells, inducible dominant inhibitory Ras inhibits cellular proliferation and delays Sindbis virus-induced apoptosis. These findings suggest that a Ras-dependent signaling pathway is a determinant of neuronal susceptibility to Sindbis virus-induced apoptosis.

Clonal analysis of stably transduced human epidermal stem cells in culture

We have transduced normal human keratinocytes with retroviral constructs expressing a bacterial beta-galactosidase (beta-gal) gene or a human interleukin-6 (hIL-6) cDNA under control of a long terminal repeat. Efficiency of gene transfer averaged approximately 50% and 95% of clonogenic keratinocytes for beta-gal and hIL-6, respectively. Both genes were stably integrated and expressed for more than 150 generations. Clonal analysis showed that both holoclones and their transient amplifying progeny expressed the transgene permanently. Southern blot analysis on isolated clones showed that many keratinocyte stem cells integrated multiple proviral copies in their genome and that the synthesis of the exogenous gene product in vitro was proportional to the number of proviral integrations. When cohesive epidermal sheets prepared from stem cells transduced with hIL-6 were grafted on athymic animals, the serum levels of hIL-6 were strictly proportional to the rate of secretion in vitro and therefore to the number of proviral integrations. The possibility of specifying the level of transgene expression and its permanence in a homogeneous clone of stem cell origin opens new perspectives in the long-term treatment of genetic disorders.

[Clinical experience with the use of implantable vascular systems in advanced heart failure]

BACKGROUND

Patients with end-stage cardiomyopathy frequently require acute or chronic infusional treatments and long hospitalization. Availability of a simple and safe vascular access is a true necessity for these patients, especially in case of inotropic or diuretic outpatient treatment. In this study we have evaluated the usefulness and the applicability of implantable vascular access in the management of end-stage cardiomyopathy. Technical problems and both short and long term complications have been analysed.

METHODS

Nineteen implantable vascular system (16 Port-A-Cath, Pharmacia; 3 Celsite, Bruneau) have been implanted in a group of 15 patients with end-stage cardiomyopathy. All patients had been previously hospitalized and needed prolonged infusional therapy. Implantation was performed in local anaesthesia with technique derived from pace-maker implantation.

RESULTS

All the interventions were well tolerated, average procedural time was 30 min (range 20-60 min). No procedural complications occurred. Re-implantation of the system was required in 2 patients due to catheter thrombosis, In 1 patient due to catheter rupture caused by wrong positioning of infusion needle, and in 1 patient due to inflammatory reaction. In 2 further cases catheter thrombosis was treated with local infusion of urokinase. In 1 patient the catheter was repositioned after dislocation. The average in situ permanence of the systems was 8 months (range 15 day-18 months).

CONCLUSIONS

Vascular implantable systems have proved useful and easily applf1p4e in the management of patients with end stage cardiomyopathy. After training some of the implied complications are easily avoidable. The use of this device has concurred to reduce duration and frequency of hospitalizations.

[Invasive, non-surgical treatment of post-traumatic pancreatic pseudocyst. Report of a clinical case]

The authors report on a pancreatic post-traumatic pseudocyst treated by a percutaneous drainage under ultrasonographic control, with a good outcome. The introduction in the past decade of new endoscopic techniques and interventional radiology, has increased the opportunity of treatment for pancreatic pseudocyst.

Familial cavernous hemangioma with atypical neuroimaging

Three members of the same family were studied, all of whom had multiple intracerebral cavernous angiomas for which a dominant autosomal inheritance was hypothesised. The proband suffered from headaches, and physical examination revealed evident right hemiparesis. The second case started with a hemorrhagic cerebral stroke and the third was asymptomatic on neurological examination. Nuclear magnetic resonance (NMR), performed in two of the three cases, showed lesions whose number and extent were not radiologically characteristic of cavernous angioma. A cerebral biopsy of the proband enabled the diagnosis to be made. Despite the recent introduction of NMR, the nosological classification of familial forms can be difficult when the radiological lesions are atypical. In such cases, cerebral biopsy is not only a valid diagnostic aid, but is also indispensable for obtaining adequate genetic information.

[Management control and operative budget at a radiology center]

The laws reforming the National Health Service (SSN) (DL 30.12.92 n. 502 converted into DL 7.12.93 n.517) strongly modify the operation rules of the local sociosanitary units (USL) and imply that the rules themselves be reorganized with flexible and agile organization systems, introducing, in addition, a budget system as a tool for programming and checking the results. The essential elements for management evaluation are: -an accurate accounting system for every department, based on a detailed analysis of the productive factors directly used; -a survey of the activity data with uniform and established indices. This work deals with a radiology department as a responsible unit belonging to Imola State Administration. It is an intermediate service as its activity is for both in- and outpatients. To calculate the cost of the service provided to users and to define the use of resources, inpatients and outpatients costs were included. This involves adding the cost of the examinations requested of the intermediate service, that is, the radiology department. The operative tool used to ascribe the cost of these demands to the departments needs a transfer cost system showing the increasing value of the number of services that the intermediate service gives the final user. To evaluate the activity of the radiology department, we tried to identify an index of respective complexity for every examination: a figure which allows us to express the use of resources according to the complexity of the services given and to turn the number of examinations into significant activity.

Ethylene-oxide and steam-sterilised polysulfone membrane in dialysis patients with eosinophilia

Eosinophilia and some acute dialysis side-effects, such as itching, flushing and bronchospasm, are often associated with the presence of ethylene oxide (ETO) as dialyzer sterilizing agent. This study evaluated the effects of two different polysulfone (PS) hollow-fiber dialysers sterilized with ETO and steam in 31 chronic dialysis patients with eosinophilia. Clinical symptoms, metabolic and biochemical parameters, complement (C3a and C5a) activation and production were evaluated in each patient dialysed for two months at a time with Cuprophan dialyser, ETO-PS dialyser and steam-PS dialyser. The steam-sterilizer agent does not alter the purifying capacity of the PS membrane which maintains its superiority over Cuprophan in terms of biocompatibility. Using steam-PS, intradialytic eosinophil kinetics seems to improve. In some patients with high serum levels of ETO-specific IgE these levels tend to diminish. Generic intradialytic symptoms do not differ between the two sterilization methods, although some hypersensitivity symptoms during the first dialysis hour are considerably lower in some patients when steam-sterilized PS is used.

In vitro testing of a left ventricular assist device. Study of the effect of its control strategy on energetic relationships inside the left ventricle

In this study an original left ventricular assist device is tested on an open loop modular physical circuit reproducing Starling's law of the heart to set an optimal control strategy for heart recovery. It is assumed that the goals of the assistance are reduction of oxygen consumption, external work and improvement of cardiac mechanical efficiency. The assistance is evaluated by the position of a working point on the characteristic surfaces of the ventricle defined by peripheral resistance, atrial pressure and selected variables pertaining to energy (pressure-volume area, external work and cardiac mechanical efficiency). In this frame an optimal assistance for heart recovery is a compromise among different requirements corresponding to a restricted set of control parameters values: driving pressure PZB = 35 kPa and timing values T1 and T2 (systole beginning and systole ending in relation to QRS complex and cardiac cycle duration T) T1 = 0.55.T and T2 = 0.73.T.

Combination treatment versus LHRH alone in advanced prostatic cancer

Androgen deprivation based on hormone manipulation is the treatment of choice in advanced prostatic cancer. The unequivocal role of adrenal androgens in the growth of prostatic cancer after medical or surgical castration requires a new logical approach (complete androgen blockade) in the treatment of advanced prostate cancer. One hundred and fifty patients with biopsy-proven advanced prostatic cancer were randomized into two groups. One group (74 patients) received leuprolide + flutamide (complete androgen blockade); the second group (76 patients) received only leuprolide and, during the first 3 weeks of treatment, cyproterone acetate (150 mg/day) to prevent flare-up phenomena. The aim of the study was to evaluate the differences between the two groups on overall survival and time to progression (log-rank test). One hundred and twenty-five patients were evaluable, 62 in the leuprolide-only group and 63 in the leuprolide + flutamide group. Median duration of follow-up was 102 weeks. No statistical difference between the two groups was observed in overall survival, in time to disease progression, and in time to treatment failure. In the combination (leuprolide + flutamide) treatment group, a positive trend for overall survival and in time to progression was observed in a subgroup of patients with good performance status and no bone metastases. We observed mild gastrointestinal toxicity (diarrhea, nausea) in the group treated with leuprolide + flutamide. The aim of this study was to compare the effectiveness of total androgen withdrawal with medical testicular suppression in advanced prostatic cancer. No significant statistical difference was observed between the two groups in overall survival and in time to progression, but probably too few patients were enrolled in each treatment arm to give a statistical interpretation of our results. We conclude that there is a positive trend in the combination treatment arm in patients with good prognostic factors.

A novel molecular complex expressed on immature B cells: a possible role in T cell-independent B cell development

To identify surface molecules that may play a role in regulating ileal Peyer's patch (PP) B cell growth, we generated monoclonal antibodies (mAbs) and then selected them for a unique reactivity with ileal PP B cells. Flow cytometric analysis identified a mAb (SIC4.8R) that labeled 97% of ileal and 50-60% of jejunal PP sIgM+B cells. SIC4.8R also labeled a subpopulation of cortical thymocytes buy few B or T cells in other lymphoid tissues, including bone marrow. Immunohistochemistry revealed intense SIC4.8R staining of B cells in the cortex of ileal PP follicles. SIC4.8R also labeled bovine PP B cells, a murine pro-B cell line, and pre-B cells in human bone marrow. Protein chemistry revealed that a structurally similar molecular complex was expressed on sheep ileal PP B cells and thymocytes and murine pro-B cells. Addition of soluble SIC4.8R to cultured ileal PP B cells reduced apoptotic cell death, elevated proliferative responses, partially inhibited anti-Ig-induced cell death, and induced IL-4 responsiveness. In contrast, soluble SIC4.8R had an antiproliferative effect on a mouse pro-B cell line. Finally, SIC4.8R labeling declined following the stimulation of ileal PP B cells with CD40 ligand. In conclusion, the present investigation determined that SIC4.8R identified a novel molecular complex that is expressed at several stages of T cell-independent B cell development in a variety of mammalian species. This observation confirmed that PP B cells are developmentally distinct from other B cell populations in sheep and suggested that the bone marrow may not be a site of B lymphopoiesis in young lambs.

N-acetylcysteine-promoted survival of PC12 cells is glutathione-independent but transcription-dependent

Our prior work established that comparable concentrations of N-acetylcysteine (NAC) both block the proliferation of PC12 cells and prevent death of trophic factor-deprived sympathetic neurons and PC12 cells. The present work addresses several aspects of the mechanisms of these actions. NAC increases intracellular levels of glutathione (GSH) by approximately 10-fold in PC12 cells. However, blockade of this increase by treatment with buthionine sulfoximine did not affect either promotion of survival or inhibition of DNA synthesis. Thus, these actions of NAC are independent of its effects on intracellular GSH. NAC's actions in our system do not appear to be dependent on its anti-oxidant/radical scavenger properties, but may be due to its activity as a reductant. Consistent with this, several other reducing agents, the most effective of which was 2,3-dimercaptopropanol, mimicked NAC in blocking DNA synthesis and suppressing death of PC12 cells and sympathetic neurons. Finally, we observed that in striking contrast to nerve growth factor and a number of other trophic agents, the survival-promoting effects of NAC on PC12 cells are blocked by actinomycin D. This suggests that NAC may act by inducing specific gene expression.

A nonproducer, interfering human immunodeficiency virus (HIV) type 1 provirus can be transduced through a murine leukemia virus-based retroviral vector: recovery of an anti-HIV mouse/human pseudotype retrovirus

The expression of a human immunodeficiency virus (HIV) type 1 provirus (F12-HIV) cloned from a nonproducer, chronically infected CD4 down-regulated Hut-78 cell clone (F12) does not lead to the formation of viral particles and, upon transfection in HeLa CD4+ cells, confers resistance to HIV superinfection without affecting the CD4 receptor exposure. In an attempt to transfer the anti-HIV properties of F12-HIV into human primary cell, we constructed a Moloney murine leukemia virus-based retroviral vector containing an F12-HIV genome lacking the 3' long terminal repeat and part of the nef gene, which was expressed under the control of its 5' long terminal repeat. The F12-HIV genome was inserted in the orientation opposite to that of the murine leukemia virus transcriptional unit and was designated the N2/F12-HIV nef-antisense vector. Lymphoblastoid CEMss cells, as well as human peripheral blood lymphocytes, were successfully transduced by the recombinant retrovirus emerging from the producer PA317 clones. CEMss clones expressing the F12-HIV nef-antisense vector became resistant to HIV superinfection even at the highest utilized multiplicity of infection (10(5) 50% tissue culture infective doses per 10(6) cells). In transduced CEMss cells the viral interference induced by the F12-HIV expression is not due to CD4 HIV receptor down-regulation. Nonproducer, interfering HIV proviruses transduced into retroviral vectors may, therefore, provide an alternative strategy for the protection of CD4+ human primary cells from HIV infection, which strategy may be used in designating a safe and efficient gene therapy protocol for patients with AIDS.

Gene therapy in peripheral blood lymphocytes and bone marrow for ADA- immunodeficient patients

Adenosine deaminase (ADA) deficiency results in severe combined immunodeficiency, the first genetic disorder treated by gene therapy. Two different retroviral vectors were used to transfer ex vivo the human ADA minigene into bone marrow cells and peripheral blood lymphocytes from two patients undergoing exogenous enzyme replacement therapy. After 2 years of treatment, long-term survival of T and B lymphocytes, marrow cells, and granulocytes expressing the transferred ADA gene was demonstrated and resulted in normalization of the immune repertoire and restoration of cellular and humoral immunity. After discontinuation of treatment, T lymphocytes, derived from transduced peripheral blood lymphocytes, were progressively replaced by marrow-derived T cells in both patients. These results indicate successful gene transfer into long-lasting progenitor cells, producing a functional multilineage progeny.