Compréhension/acceptation de la radiothérapie : un dilemme éthique résolu par une éthique de la considération et de la sollicitude

PURPOSE

Ethical questions are poorly investigated specifically in radiation oncology. The objective of the study was to identify and understand the main ethical issue in radiation oncology.

MATERIALS AND METHODS

A quantitative analysis was based on the answers to a questionnaire of 200 professionals from 22 radiation oncology departments. The questionnaire mainly aimed to characterize the main ethical issue. A monocentric qualitative analysis was based on semi-structured interviews focused on the main identified ethical issue, carried out with eight technologists, and 20 patients undergoing radiotherapy.

RESULTS

The main ethical issue was the understanding and/or acceptance of the treatment by the patients (71 %), which frequently arises (more than once a month) (52 %), and corresponds to an ethical tension between the principles of respect for autonomy and beneficence (the good as viewed by the patient) as defined by Beauchamp and Childress. The technologists, wish the patient to be fully involved in his treatment, with the even possibility of refusing it. However, excluding paternalism and autonomic relentlessness, the technologists have the feeling of acting for the good of the patients by treating them with radiation, even if the patients are not always aware of it, because they are within a situation of vulnerability. If the hierarchy of principles is a compromise alternative, this problem is finally well resolved by the effective implementation of an ethic of consideration and solicitude, restoring the patient capabilities, i.e. the maximum development of his potentialities in his situation of vulnerability. Beyond the legal dimension, patient information is crucial and must consider the specific temporality of the patient.

CONCLUSION

The main ethical issue in radiation oncology is the understanding and/or acceptance of the treatment involving the development of an ethic of consideration and solicitude.

[Vulnerabilities, ethical responsibility and acceptance of otherness during the first Covid lockdown: A case study of a French Care Centre for Support and Prevention in Addictology]

Le premier confinement de la crise sanitaire Covid 19 a bouleversé les pratiques médicales et soignantes, avec une priorisation des patients positifs à la Covid et une focalisation sur les flux en réanimation. Or, dans les Centres de Soin d’Accompagnement et de Prévention en Addictologie (CSAPA), la dimension relationnelle du soin est centrale. Les professionnels de santé ont été impactés par les protocoles contraignants en matière d’asepsie, avec un risque de rupture de suivi accru chez des patients déjà vulnérables. À partir du cas du CSAPA de Grasse, l’article vise premièrement à analyser rétrospectivement les tensions éthiques rencontrées autour de l’accueil de l’altérité de ces patients aux problématiques complexes et deuxièmement à mettre en lumière l’inventivité des soignants dans leurs pratiques quotidiennes. L’approche développée est philosophique et conceptuelle, centrée sur la philosophie d’E. Levinas et son éthique du « visage » car la crise a exacerbé des tensions éthiques préexistantes autour de l’intersubjectivité. Les soignants ont dû faire face à une « responsabilité pour autrui », elle aussi renforcée. Mais la crise a pu aussi être l’occasion de réinvestir le soin relationnel, en se détachant du primat de la vue: le masque a tantôt aidé tantôt entravé le soin relationnel, mettant au jour la vulnérabilité partagée des soignants et des soignés. La crise sanitaire nous rappelle que la vigilance est toujours de mise vis-à-vis des risques de déshumanisation de la relation de soin.

Identifying the impact of the confinement of Covid-19 on emotional-mood and behavioural dimensions in children and adolescents with attention deficit hyperactivity disorder (ADHD)

The current study examined the impact of the lockdown due to the Covid-19 disease on mood state and behaviours of children and adolescents with ADHD. Nine hundred ninety-two parents of children and adolescents with ADHD filled out an anonymous online survey through the ADHD family association website. The survey investigated the degree of severity of six emotional and mood states (sadness, boredom, little enjoyment/interest, irritability, temper tantrums, anxiety) and five disrupted behaviours (verbal and physical aggression, argument, opposition, restlessness) based on their frequency/week (absent; low: 1-2 days/week; moderate: 3-4 days/week; severe: 5-7 days/week) before and during the lockdown. Important fluctuations were found in all dimensions during the lockdown independently by the severity degree. Subjects with previous low severity degree of these behaviors significantly worsened in almost all dimensions during the lockdown. On the contrary, ADHD patients with moderate and severe degree showed important improvement during the lockdown. Little enjoyment/interests and boredom resulted the dimensions more strongly affected by the condition of restriction, overall in children. Children vs. adolescents showed substantially similar trend but the former resulted significantly more vulnerable to emotive changes. The results provided both the individuation of domains affected, and the indirect benefits produced by restriction condition.

Attached molecular motor in a trapped single molecule assay as a bidimensional Brownian multistable system

To elucidate the physical properties of the force generation mechanism in molecular motors, we have obtained an analytical solution of the bidimensional Fokker-Plank equation which describes a common setup used in single molecule experiments. As a first application of this general result, we have shown that the size of the trapping system affects the dwell time of a multistable particle linearly. A quantitative application to skeletal actomyosin complex, using direct observation of force generation dynamics in the literature, shows that the size of the trapping system used was important for increasing the dwell time of the myosin head stable states to an observable time scale.

[Spontaneous rupture of extensor pollicis longus in isolated trapeziometacarpal arthritis]

A spontaneous rupture of the extensor pollicis longus (EPL) tendon occurred in a patient with trapeziometacarpal arthritis. We hypothesize that a mechanical attrition by protrusion at the trapeziometacarpal joint alone was responsible of a spontaneous rupture of the extensor pollicis longus tendon.

Semen quality in men with Y chromosome aberrations

Infertile males sometimes bear structurally balanced chromosome aberrations, such as translocations and inversions, which involve both autosomes and sex chromosomes. The aim of this study was to evaluate genotype-phenotype correlations in a sample of infertile men with various types of Y chromosome abnormalities. In particular, we examined the effect of (i) balanced structural aberrations such as translocations between sex chromosomes and autosomes; (ii) unbalanced structural aberrations such as deletions or isodicentrics, both [idic(Yp)] and [idic(Yq)]. We studied 13 subjects bearing Y chromosome aberrations. Each patient underwent seminal fluid examination, andrological inspection, hormone study, testicular ultrasound, conventional and molecular cytogenetic analysis and study of Y chromosome microdeletions. Comparison of genotype and sperm phenotype in infertile patients with various Y chromosome aberrations revealed the key role of meiotic pairing defects in arresting spermatogenesis, both in the presence and in the absence of azoospermic factor microdeletions and cell mosaicism. The failure of meiosis and, in consequence, spermatogenesis may be a result of the failure to inactivate the X chromosome in the meiotic prophase, which is necessary for normal male spermatogenesis to take place.

Muscle contraction: A mechanical perspective

In this paper we present a purely mechanical analog of the conventional chemo-mechanical modeling of muscle contraction. We abandon the description of kinetics of the power stroke in terms of jump processes and instead resolve the continuous stochastic evolution on an appropriate energy landscape. In general physical terms, we replace hard spin chemical variables by soft spin variables representing mechanical snap-springs. This allows us to treat the case of small and even disappearing barriers and, more importantly, to incorporate the mechanical representation of the power stroke into the theory of Brownian ratchets. The model provides the simplest non-chemical description for the main stages of the biochemical Lymn-Taylor cycle and may be used as a basis for the artificial micro-mechanical reproduction of the muscle contraction mechanism.

Mechanics of the power stroke in myosin II

Power stroke in skeletal muscles is a result of a conformational change in the globular portion of the molecular motor myosin II. In this paper we show that the fast tension recovery data reflecting the inner working of the power stroke mechanism can be quantitatively reproduced by a Langevin dynamics of a simple mechanical system with only two structural states. The proposed model is a generalization of the two state model of Huxley and Simmons. The main idea is to replace the rigid bistable device of Huxley and Simmons with an elastic bistable snap spring. In this setting the attached configuration of a cross bridge is represented not only by the discrete energy minima but also by a continuum of intermediate states where the fluctuation induced dynamics of the system takes place. We show that such soft-spin approach explains the load dependence of the power stroke amplitude and removes the well-known contradiction inside the conventional two state model regarding the time scale of the power stroke.

Correlation in foveal thickness measurements between spectral-domain and time-domain optical coherence tomography in normal individuals

PURPOSE

To compare a time-domain (Stratus) and a spectral-domain (Spectralis) optical coherence tomography (OCT) device in assessing foveal thickness in healthy subjects.

METHODS

In this observational study 40 healthy subjects (40 eyes) underwent Stratus OCT and Spectralis OCT measurements of foveal thickness using three consecutive horizontal and vertical B-scan. Paired samples t-test was used to compare means between Stratus and Spectralis OCT measurements. Coefficient of variation (CoV) was used to compare dispersion in datasets. Pearson's correlation coefficient was used to quantify linear relation between Spectralis and Stratus OCT measurements. To assess agreement between Spectralis and Stratus OCT foveal thickness measurements, the Bland and Altman plots were used.

RESULTS

Sample age ranged from 19 to 49 years (mean 33.25, standard deviation (SD) +/-4.22). The Spectralis OCT foveal thickness measurements resulted significantly higher than those obtained with Stratus OCT (227.64+/-11.74 vs 144.36+/-12.25 microm, and 227.63+/-11.43 vs 144.92+/-12.34 microm, for horizontal and vertical foveal thickness, respectively) (P<0.05). Coefficient of variations were 5.16 and 5.02% using Spectralis OCT, and 8.49 and 8.51% using Stratus OCT. Mean Spectralis/Stratus ratio was 1.58 for both horizontal and vertical measurements. A linear relation between the two technologies was found (r(horiz)=0.899 and r(vert)=0.869) (P<0.001).

CONCLUSIONS

A good correlation between Stratus and Spectralis OCT foveal measurements was found, independently of retinal thickness. This preliminary study suggests the existence of a conversion factor between Stratus and Spectralis OCT when measuring healthy foveal thickness.

Traitement de la rhizarthrose par prothèse métacarpienne de resurfaçage

PURPOSE OF THE STUDY

The aim of this study was to present our experience with hemiarthroplasty of the base of the first metacarpal for the treatment of degenerative disease of the trapeziometacarpal joint. We have used this resurfacing implant since 1995 as part of our therapeutic armamentarium together with trapeziectomy, arthrodesis and total arthroplasty.

MATERIAL AND METHODS

The chromium-cobalt implant is inserted into the base of the first metacarpal. Three implant sizes are available. The present series included 106 implants in 87 patients, predominantly female. Mean patient age was 59.6 years. Three quarters of the patients had isolated joint degeneration. The preoperative complaint was pain (scored 3 on a 4-point scale) for 92% of patients. Joint motion was generally not impaired. Grip force was limited with less than 50% force for first finger-thumb opposition in three quarters of the patients. The anterior Gedda-Möberg approach was used in all cases. The joint was immobilized for two to three weeks postoperatively.

RESULTS

There were seven complications among the 106 cases: reflex dystrophy (n=4), global pain (n=2) and rupture of the long extensors (n=1). Sixty nine patients (83 implants) were reviewed at more than one year follow-up. Mean follow-up was 53 months (range 23 - 128 months). Activities were resumed at two months for 88% of implants with no problem for grip force for one-third and normal activity for 66%. Patient assessment was: outcome good and very good for 94%, pain free for 52%, and moderate pain without impaired activity for 43% (Kapandji opposition score was normal in 90%). Grip force was decreased in 25%. Radiographically, all implants were stable. Joint centering was improved (from 25% to 60% at last follow-up). There was no correlation between radiographic centering and clinical outcome.

DISCUSSION

This hemiarthroplasty has provided satisfactory results in terms of pain relief, joint motion, and function. There has not been any long-term radiographic problem. If revision is needed for failure, the procedure is simple and trapeziectomy, total arthroplasty or arthrodesis can be performed. The hemi-implant can be inserted after total arthroplasty. Compared with other techniques, this implant avoids the problem of silicone tolerance with the Swanson implant and has provided results superior to those of arthrodesis and trapiezectomy but slightly less satisfactory than with total arthroplasty. The indication for use of this resurfacing implant is osteoarthritis of a centered trapeziometacarpal in the young subject. The implant is contraindicated for advanced-stage disease, stiff joint with retraction of the first commissure and hyperextension of the metacarpophalangeal joint.

First-line 5-fluorouracil/folinic acid, oxaliplatin and irinotecan (FOLFOXIRI) does not impair the feasibility and the activity of second line treatments in metastatic colorectal cancer

BACKGROUND

We conducted two phase II trials evaluating the combination of 5-fluorouracil/folinic acid, oxaliplatin and irinotecan (FOLFOXIRI) as first-line treatment in 74 metastatic colorectal cancer patients. Results were very promising with an overall response rate of 71% and 72%, a median PFS of 10.4 and 10.8 months and an overall survival of 26.5 and 28.4 months, respectively. A concern about the use of all three active agents up-front is the possibility that this might limit, after progression, disease control with second-line treatments. Therefore, we conducted the present analysis to evaluate the outcome of second-line treatments in these 74 patients.

METHODS

Among the 71 patients so far progressed 54 (76%) received second line chemotherapy (23: FOLFIRI, 17: FOLFOXIRI, five: 5-FU protracted infusion, three: FOLFOX, three: 5-FU+MMC, two: CPT-11, one: CPT-11+LOHP, one: raltitrexed). Seventeen patients (24%) did not receive second line treatments: 10 because of deterioration of performance status (PS), four because of patient refusal and three because of death. Patients' characteristics at the time of second-line treatment were: M/F 36 of 18 patients, median age 64 yrs (range 44-75), ECOG PS>or=1 21 (39%) patients, multiple sites of disease 33 (61%) patients.

RESULTS

A median of 4.1 months of second-line chemotherapy per patient were administered (range 1-8). Overall response rate (52 out of 54 evaluable patients) was 33% and stable disease were 19 (37%). Median duration of response was 8.1 months. At a median follow up of 15.1 months from the start of salvage chemotherapy median PFS and overall survival were respectively 6.7 and 15.2 months.

CONCLUSIONS

First-line FOLFOXIRI does not impair the possibility to obtain objective responses and delay tumor progression with second line treatments containing the same agents used in first-line.

First-line treatment of metastatic colorectal cancer with irinotecan, oxaliplatin and 5-fluorouracil/leucovorin (FOLFOXIRI): results of a phase II study with a simplified biweekly schedule

BACKGROUND

In a previous phase I-II study we demonstrated that the FOLFOXIRI regimen [irinotecan 125-175 mg/m2 day 1, oxaliplatin 100 mg/m2 day 1, l-leucovorin (l-LV) 200 mg/m2 day 1, 5-fluorouracil (5-FU) 3800 mg/m2 as a 48-h chronomodulated continuous infusion starting on day 1, repeated every 2 weeks] has promising activity and efficacy in metastatic colorectal cancer. However, this regimen required a chronomodulated infusion of 5-FU, and because neutropenia occurred in 32% of cycles, granulocyte colony-stimulating factor (G-CSF) was used and the delivered dose intensity was only approximately 78% of planned. Therefore, we conducted the present phase II study in order to develop a simplified FOLFOXIRI regimen that could be more easily administered in clinical practice as well as in multicenter settings.

PATIENTS AND METHODS

A total of 32 patients with unresectable metastatic colorectal cancer received irinotecan 165 mg/m2 day 1, oxaliplatin 85 mg/m2 day 1, l-LV 200 mg/m2 day 1 and 5-FU 3200 mg/m2 as a 48-h continuous (not chronomodulated) infusion starting on day 1, repeated every 2 weeks.

RESULTS

All 32 patients were evaluated for safety and the incidence of grade 3-4 toxic effects, and the use of G-CSF seemed to be lower than with the previous FOLFOXIRI regimen: grade 4 neutropenia (34%), grade 3 diarrhea (16%), grade 3 stomatitis (6%) and grade 2-3 peripheral neurotoxicity (37%) were reported, and G-CSF was used in 23% of cycles. Delivered dose intensity was 88% of that planned, and no toxic deaths occurred. The intention-to-treat analysis for activity showed four complete responses, 19 partial responses, seven stable disease and two progressive disease, for an overall response rate of 72% (95% confidence interval 53% to 86%). Eight (25%) patients with residual liver or lung metastases were radically resected after chemotherapy. After a median follow-up of 18.1 months, the median progression-free survival is 10.8 months and median survival is 28.4 months.

CONCLUSIONS

This simplified FOLFOXIRI combination can be delivered easily in outpatient settings, with manageable toxic effects, and has very promising antitumor activity. While the safety profile seems to be improved in comparison with our previous FOLFOXIRI regimen, antitumor activity and efficacy appear to be maintained.

Chromosome instability in T-cells cultured in the presence of pancuronium or fentanyl

BACKGROUND

Genomic instability is recognized as a cause of cellular apoptosis and certain drugs that exhibit a proapoptotic effect are also able to induce chromosome damage. Since we found in recent experiments that drugs such as pancuronium and fentanyl exerted an apoptogenic effect on T cells, we studied the capacity of those agents to promote chromosome instability, i.e. chromosome aberrations (CA) and telomeric associations (tas) in peripheral blood lymphocytes.

METHODS

Lymphocytes from healthy donors were cultured with pancuronium or fentanyl, using two different concentrations for each drug: 20 and 200 ng/ml for pancuronium and 10 and 30 ng/ml for fentanyl, respectively. Cells were exposed to each concentration of these drugs either for 24 or 48 h. The higher concentration chosen was the same at which we detected the proapoptotic effect in our previous works. Cytogenetic analysis was performed by means of a standard technique and chromosome aberrations or telomeric associations were blindly evaluated by two independent observers.

RESULTS

The chromosome aberrations we observed in treated cells were not significantly different from control lymphocytes. However, an unusual rate of telomeric associations (P < 0.001) was detected in cells exposed to both pancuronium and fentanyl, at each concentration tested and at each exposure time of the study.

CONCLUSIONS

Fentanyl and pancuronium do not have a direct clastogenic effect on T cultures, but at the same concentrations at which we demonstrated their apoptogenic power, these drugs are able to increase genomic instability through inducing an elevated rate of telomeric associations. Such a capacity could exploit in peripheral T cells the same mitochondrion-mediated signal pathway of apoptosis death.

Telomerase activity, apoptosis and cell cycle progression in ataxia telangiectasia lymphocytes expressing TCL1

Individuals affected by ataxia telangiectasia (AT) have a marked susceptibility to cancer. Ataxia telangiectasia cells, in addition to defects in cell cycle checkpoints, show dysfunction of apoptosis and of telomeres, which are both thought to have a role in the progression of malignancy. In 1-5% of patients with AT, clonal expansion of T lymphocytes carrying t(14;14) chromosomal translocation, deregulating TCL1 gene(s), has been described. While it is known that these cells can progress with time to a frank leukaemia, the molecular pathway leading to tumorigenesis has not yet been fully investigated. In this study, we compared AT clonal cells, representing 88% of the entire T lymphocytes (AT94-1) and expressing TCL1 oncogene (ATM(-) TCL1(+)), cell cycle progression to T lymphocytes of AT patients without TCL1 expression (ATM(-) TCL1(-)) by analysing their spontaneous apoptosis rate, spontaneous telomerase activity and telomere instability. We show that in ATM(-) TCL1(+) lymphocytes, apoptosis rate and cell cycle progression are restored back to a rate comparable with that observed in normal lymphocytes while telomere dysfunction is maintained.

Telomeric associations and chromosome instability in ataxia telangiectasia T cells characterized by TCL1 expression

T-cell tumors in ataxia telangiectasia (AT), such as T-PLL/T-CLL, are first preceded by the development of a large clone of T-lymphocytes, characterized by chromosomal rearrangements, which usually involve specific regions such as the 14q11 region. Malignancy develops years later, after additional chromosomal changes resulting from the genomic instability consequent to ATM disruption and to the activation of the TCL1 oncogene. Here we report the results of a cytogenetic follow-up of an AT patient (AT94-1), still without signs of hematological abnormalities, bearing a T-lymphocyte clone characterized by the t(14;14)(q11;q32) rearrangement and having TCL1 expression. We demonstrated that in clonal cells TCL1 expression correlates with increasing genomic instability and in time this mainly induces chromosomal rearrangements and telomeric associations (tas). Chromosome 21 is not randomly involved; in particular, an i(21q) indicates that it is a subclone prone to additional genetic changes and could represent an early chromosomal rearrangement involved in tumorigenesis. With regard to the increase in tas, we observed that: (i) it is inversely correlated with the proliferative ability of AT94-1 lymphocytes in PHA-stimulated short-term cultures (cell aging in vitro); (ii) this increase is not due to changes either in cell radiosensitivity (measured as bleomycin (BML)-sensitivity) or due to an illegitimate recombination (measured as adriamycin-sensitivity), which may not be sufficient for tumor development.

Chromosomal alterations and male infertility

Reduced male fertility can be caused by genetic factors affecting gamete formation or function; in particular, chromosome abnormalities are a possible cause of male subfertility as shown by their higher frequency in infertile men than in the general male population. Meiotic studies in a number of these males have shown spermatogenesis breakdown, often related to alterations in the process of chromosome synapsis. Indeed, any condition that can interfere with X-Y bivalent formation and X-chromosome inactivation is critical to the meiotic process; furthermore, asynapsed regions may themselves represent a signal for the meiotic checkpoint that eliminates spermatocytes with synaptic errors. We performed cytogenetic, hormonal and seminal studies in 333 infertile patients selected because azoospermic, severely oligozoospermic or normozoospermic with failure to fertilize the partner's oocytes in an in vitro fertilization (IVF) program. Our findings: 1) confirm the high incidence of chromosomal anomalies among infertile males; 2) highlight the relevance in male infertility of quantitative/positional modifications of the constitutive heterochromatin; and 3) underline the relevance of cooperation between andrologists and cytogenetists prior to every kind of assisted reproduction, above all prior to intracytoplasmic sperm injection, in which selective hurdles eliminating abnormal germ cells are bypassed.

Supraceliac aortic pseudoaneurysms after liver transplantation in infants

BACKGROUND

Reconstruction of the hepatic artery in infants undergoing liver transplantation presents challenging vascular situations. Microvascular techniques ensure arterial blood flow via small caliber vessels but are insufficient when inflow is poor. In these situations, the use of allogeneic grafts to the supraceliac aorta have been advocated. The development of a pseudoaneurysm at the supraceliac aortic suture line requires urgent repair and restoration of arterial flow to the graft.

METHODS

Our study was based on case reports and review of the literature.

RESULTS

Definitive diagnosis and successful repair of supraceliac pseudoaneurysm was accomplished in two infants after transplantation.

CONCLUSION

We advocate a thoracoabdominal retroperitoneal approach, which provides safe control of the aorta and primary repair or patching of the diseased aortic segment, and also provides access for hepatic revascularization via placement of an infrarenal graft. Thrombosis of the artery and subsequent liver necrosis are indications for retransplantation.

[Repetitive release of the medial nerve in the carpal tunnel. Analysis of a series of 18 cases]

PURPOSE OF THE STUDY

This study analyzes 18 revision procedures for carpal tunnel release failure.

MATERIAL

This series did not present any difference in terms of age compare to the population suffering from median nerve entrapment: mean age 56 years, 17 female and 1 male, 1 monolateral syndrome and 8 bilateral. Two third of the patients were seen between 2 and 9 months after initial surgical treatment. Most of the first surgical procedures were performed by an orthopedic surgeon (12/18). The approach was open (14/18) with 5 short incisions, and 4 endoscopic releases. Clinical symptoms were worse or unchanged compare to prior to surgery. All the patients had EMG study and 15 had worse electric signs than before. Open surgical approach was always palmar using optic magnification for median nerve neurolysis.

RESULTS

16 times an incomplete section of the anterior retinaculum and 2 median nerve lacerations were found. All patients were seen with a follow up of more than 2 months. Results concerning pain and sensibility were good for 16 of them; regarding motor impairment, only 13 of them had a good result. Grasp was not improved for 50 per cent of them. Two patients had a result considered as bad (one NAD sequela and one median total laceration).

DISCUSSION

In our series as well as in literature, failures of carpal tunnel release are due to incomplete section of the anterior retinaculum and sometimes to median nerve laceration. The second look has to be performed when there is no improvement or when the situation is worse after initial surgery.

CONCLUSION

Incomplete section of the anterior retinaculum is the most frequent reason for carpal tunnel release failure. An EMG seems necessary to confirm diagnosis before revision surgical procedure.

A synthetic CD4-CDR3 peptide analog enhances skin allograft survival across a MHC class II barrier

The efficacy of a synthetic peptide analogue (rD-mPGPtide), mimicking the CDR3 region in the first domain of the CD4 surface molecule, was investigated in a murine model for CD4+ T cell-mediated skin allograft rejection. A single injection of rD-mPGPtide shortly before transplantation exhibited significantly prolonged graft survival in the B6 anti-B6.C-H2bm12 MHC class II-disparate strain combination. Long-term graft survival (>100 days) was achieved when thymectomized adult recipient mice were transplanted along with rD-mPGPtide treatment. The peptide also affected secondary rechallenge responses with MHC class II allografts. In addition, the inhibitory effect of the rD-mPGPtide in this transplantation model was directed against CD4+ T cells and was exclusively specific toward donor alloantigen. In vitro analysis of CD4+ T cells isolated from the draining lymph nodes of rD-mPGPtide-treated recipients indicated a 450-fold decrease in precursor frequency in response to donor allostimulation compared with the untreated control group. There was also significant down-regulation of the frequency of IL-2-, IFN-gamma-, and IL-4-producing CD4+ T cells upon in vitro allogeneic restimulation of host cells 4 days posttransplantation. However, these same CD4+ T cells maintained the capacity to produce normal cytokine levels upon third-party allostimulation. Thus, these studies demonstrate that a CD4-CDR3 peptide analogue can specifically and effectively prolong skin graft survival across MHC class II barriers.

Effects of poly(ADP-ribose) polymerase inhibition on cell death and chromosome damage induced by VP16 and bleomycin

Poly(ADP-ribose) polymerase (PARP) is a DNA-binding protein involved in cellular response to various genotoxic agents. To understand the role of PARP in the mechanisms which lead from specific DNA damage to cell death, we studied the effects of PARP inhibition in human lymphoblasts damaged with bleomycin (BLM) and VP16. These agents can induce DNA breakage but through different mechanisms, enabling the study of the different effects of PARP in inducing apoptosis in damaged cells. We demonstrate that in lymphoblasts VP16 treatment induces apoptosis to a greater extent than BLM treatment, and that PARP inhibition reduces VP16-induced apoptosis whereas it has no effect on BLM-induced apoptosis. After VP16 treatment with PARP inhibition, a reduction in the depletion of the proliferative compartment and a G2/M phase arrest are observed. Therefore, the increase in cell viability and the reduction in chromosome damage may both be the result of a prolonged DNA repair time. Hence, PARP appears to play a significant role in VP16-induced apoptosis and not in BLM-induced apoptosis. Since apoptosis is important in tumor treatment these findings might be useful when considering the combined employment of PARP inhibition with antineoplastic drugs.

[Primary metacarpophalangeal and proximal interphalangeal arthrosis of the hand. Indications and results of 27 DJOA arthroplasty]

The authors report 27 Digital Joint Arthroplasties (DJOA), implanted exclusively in cases of osteoarthritis, between 1985 and 1994. The metacarpophalangeal joint was involved in 8 cases and the proximal interphalangeal joint was involved in 19 cases in a series of 20 patients with a mean age of 58 years (49-84). The mean interval between the first clinical signs and the surgical operation was 34 months (12-72). An anterolateral incision was used in 5 cases for the PIP joint, and an anterior incision was used in one case for the MP joint. All other cases were operated via a dorsal incision. Two early complications were observed: septic ulceration of the skin and dislocation of the PIP prosthesis on the 8th day. Good results were obtained in terms of pain. Range of movement was only slightly improved by arthroplasty and exclusively in the extension sector. The range of movement of the MP joint increased from 35 degrees to 50 degrees, while the range of movement of PIP joint remained unchanged at 50 degrees with a slight displacement of 5 degrees towards the extension sector. This can be explained by the radiological follow-up of our implants which showed impaction of the prosthetic shaft during the first two postoperative years with appearance of signs of periarticular ossification. The results concerning range of movement and pain were analogous to those of other series in the literature, particularly with the use of Swanson implants. On the other hand, DJOA arthroplasty presents a low incidence of axial deviation problem (1 case out of 27). The authors are currently trying to improve the results of DJOA arthroplasty by creating a size 0 to suit anatomical requirements and by adopting the anterolateral incision to preserve the extensor apparatus in order to decrease postoperative flexion deformity.

Effects of topoisomerase II inhibition in lymphoblasts from patients with progeroid and "chromosome instability" syndromes

DNA topoisomerase II is involved in DNA topologic changes through the formation of a cleavable complex. This is stabilized by the antitumor drug VP16, which results in DNA breakage, aberrant recombination, and cell death. In this work, we compare the chromosomal damage induced by VP16 with that induced by bleomycin (BLM) in lymphoblasts from patients affected by the chromosome breakage syndromes ataxia telangiectasia (AT), xeroderma pigmentosum (XP), and Bloom syndrome (BS), and by the progeroid syndromes Werner (WS) and Cockayne (CS). Patients affected by AT, XP, BS, and WS have a greatly enhanced risk of developing cancer. The results show that AF and WS cells are hypersensitive to VP16, as revealed in the higher proportion of metaphases showing exchange figures and more than two breaks. All lines except AT and one CS line showed normal sensitivity to BLM. Our data on the sensitivity to VP16 of all these mutant cells underline the fact that VP16 damage is amplified only in cells that have abnormal illegitimate recombination (i.e., AT and WS).

VP16 hypersensitivity and increased faulty recombination in ataxia telangiectasia lymphocytes characterized by the tandem translocation t(14;14)(q11;q32)

Ataxia telangiectasia (AT) patients show variable degrees of immunodeficiency and a higher than normal predisposition to lymphoid malignancies. AT cells are characterized by spontaneous chromosome instability resulting in chromosome breakage and in non random chromosome rearrangements. Sequential cytogenetic studies on T-lymphocytes from an AT patient showed the progressive development of a clone bearing a tandem translocation t(14;14)(q11;q32). The abnormal clone had spontaneous chromosome rearrangements. Compared to non clonal cells, the abnormal clone displayed a higher frequency of spontaneous chromosome rearrangements. In only the clonal cells we observed two particular and predominant rearrangements: isodicentric chromosomes and telomeric associations which may derive from faulty recombination. Chromosome instability induced by the etoposide VP16, a DNA topoisomerase II inhibitor, was evaluated in terms of chromosome breakage and SCE frequency. T-lymphocytes from the AT patient showed hypersensitivity to VP16 significantly higher than normal T-lymphocytes. The chromosome instability induced by VP16 is significantly higher in clonal than in non clonal cells, whilst the chromosome instability induced by the radiomimetic drug bleomycin is not significantly different in the two AT lymphocyte subpopulations. The different spontaneous chromosome instability in clonal and non clonal cells together with their different behavior after treatment with only VP16, suggest that clonal cells bearing the tandem translocation could have increased faulty recombination. Given the presence of translocations t(14;14)(q11;q32) in T-prolymphocytic leukemias and T-cell tumors of non AT patients, our findings suggest that VP16 could be considered an antineoplastic treatment particularly indicated in these patients.

Expression of genes carried by pR plasmid in damaged E. coli and mouse cells

In LTA mouse cells pR plasmid constitutively expresses itself resulting in protection against typical SOS inducers (UV, 4NQO) and in sensitization to different DNA-damaging agents (MNNG, cisDDP, BLM and geneticin (G418). The pR sensitizing effect is specific to mammalian cells, since the plasmid can only protect prokaryotic cells against the damaging agents tested. The pR protecting effect requires the expression of both the uvp1 and uvp2 (mucAB) regions in bacteria as well as in mouse cells. The coordinated function of these regions could result in protection against typical SOS inducers through an SOS/SOS-like pathway. The sensitization conferred by pR plasmid depends mostly on the expression of the mucAB genes, as shown by the survival of mouse cells transfected with different pR::Tn5 mutants. In particular, BLM and G418 survival data demonstrate that, inserted into the pR plasmid, the ble and neo genes of the Tn5 transposon express themselves. This was confirmed by the presence of Tn5 transcripts in untreated mouse cells. The comparison between the pR effects in bacterial and mouse cells shows that during evolution the repair pathways against UV damage are better conserved than those against other kinds of damage.

[Basic elements of antibiotic prophylaxis: the rationale]

In brief, the following study shows the necessity of chemoantibioticprophylaxis. This is to be carried out in operations where the risk of contamination is probable. The antibiotic is to be administered before the operation. Active drugs are used to confront foreseen pathogenics and ensure sufficient M.I.C. for the duration of the operation itself. Moreover, the results obtained from a polycentric research are underlined. The results show post-operative infections, with particular importance being placed on the antibiotics to be used as far as isolated germs are concerned.

Neurological and cytogenetic study in early-onset ataxia-telangiectasia patients

The clinical diagnosis of ataxia-telangiectasia (AT) is difficult before the age of 4 years. We report clinical and cytogenetic data on three early-onset, early-diagnosed AT patients at the age of 12, 18 and 22 months, respectively. Postural instability of the trunk, characterized by motor impersistence, was the earliest neurological sign detected as early as 1 year of life. Dystonic movements and postures of arms and trunk and a subtle disorder of eye movement (blinking before gaze changing, increased latency and dysmetry of saccades) were observed during the 2nd year of life. All patients exhibited an unusual temper tantrum. We also observed an increased bleomycin-induced chromosomal instability in patient's cells in the early stages of the disease before all the clinical hallmarks were apparent. Our data suggest that detection of clinical indications, leading to early laboratory confirmation of AT, can reduce the age at diagnosis.

Heterogeneity in ataxia-telangiectasia: classical phenotype associated with intermediate cellular radiosensitivity

We identified a subgroup of ataxia-telangiectasia (AT) patients (2 sibs and 1 unrelated case) characterized by typical clinical manifestations of the disease and cellular radiosensitivity intermediate between classical AT and normal subjects. Our data and a literature review of the intermediate radiosensitivity AT cases show that radioresistant DNA synthesis, cellular radiosensitivity (measured in terms of survival and chromosome breakage), and the clinical hallmarks behave independently. This raises a number of interesting questions about the correlation between radiobiological and clinical features, and about the nature of the AT gene(s).

Human cells (normal and ataxia telangiectasia) transfected with pR plasmid are hypersensitive to DNA strand-breaking agents

Ataxia telangiectasia (AT) cells are known to be hypersensitive to ionizing radiations and to drugs such as bleomycin and epipodophyllotoxin VP16, a topoisomerase II poison. Both of these produce DNA double-strand breaks even if through different mechanisms. In this work we analyzed the sensitivity to bleomycin and to epipodophyllotoxin of AT cells after transfection with pR plasmid. This plasmid, interacting with bacterial SOS repair pathways, expresses itself in mammalian cells conferring cell resistance to the SOS inducers UV and 4NQO and cell sensitivity to different drugs such as bleomycin. This effect is presumably due to the interaction of pR products with double-strand breaks. Our findings indicate that pR plasmid, in both AT lines tested (AT5BIVA fibroblasts and ATL6 lymphoblasts), expresses itself (increasing UV protection) and amplifies the already enhanced AT cell sensitivity to both bleomycin and VP16.

Antibiotic prophylaxis in ear, nose and throat surgery: a comparison of a single preoperative dose with three peri-operative doses of ceftazidime

An open prospective randomized trial was conducted in three Italian ear, nose and throat (ENT) surgery departments on 120 patients aged 10 to 84 years, to compare a single pre-operative dose vs. three peri-operative doses of ceftazidime in surgical prophylaxis. Sixty patients in group I received 1 g ceftazidime intramuscularly (im) or intravenously (iv) 1 h before surgery, and 60 in group II received three 1 g doses of ceftazidime, im or iv, 1 h before, and 6 and 12 h after surgery. Post-operative infections were observed in six group I patients (10.1%) and seven group II patients (11.6%). All infections arose in patients who had undergone 'moderate-risk' (6.7%) or 'high-risk' surgery (30.5%). We conclude that a single pre-operative 1 g dose of ceftazidime is as efficacious as multiple peri-operative doses in the prophylaxis of infectious complications following this type of surgery.

[Primary amelanotic melanoma of the nasal fossa. Importance of ultrastructural study for diagnosis]

Primitive malignant melanoma of the nasal fossae is rare and amelanotic melanoma of the same site is highly unusual. The present work reports a case where positive diagnosis was only possible by means of ultrastructural study. Giving evidence of the premelanosomes, this technique made it possible to differentiate from other types of cancers (in particular from olfactory neuroblastoma, non differentiated small cell carcinomas and lymphoma). Although in all cases we are dealing with malignancies, the need for a precise histological diagnosis is fundamental to work up an adequate therapeutic protocol. Given the difficulties in getting an electronic microscope in any hospital, the method used in the present case is quite significant since it made precise diagnosis possible even on bioptic fragments fixed in non buffered formalin. Finally some problems regarding diagnosis and treatment linked to diagnosis by means of electronic microscopy are discussed.

The rep region of pR plasmid regulates the expression of SOS system

By using an artificial hybrid between phage lambda and the pR plasmid, we have shown that the rep region of the pR plasmid encodes a function which regulates the expression of the muc genes (plasmid genes that are under the negative control of lexA and responsible for an increased rate of spontaneous mutagenesis and resistance to UV and chemicals). Expression of the muc genes were monitored by a fusion between the muc promoter and the lacZ structural gene. When E. coli cells containing such a fusion are infected by the hybrid lambda pR phasmid, beta-galactosidase activity is enhanced, indicating that pR encodes an antagonist of lexA. By deletion mapping we have located the gene encoding the antagonist of lexA (bat) in the rep region of the plasmid. The bat gene product can also antagonize the lambda cI repressor as shown by the observation that lambda pR phasmids are virulent on a homoimmune lysogen. We have exploited this latter property to carry out genetic and functional analysis of the bat region. This region is organized as a classical operon where the expression of the bat structural gene is negatively regulated by a repressor gene that encodes a proteic product.

The pR plasmid: a tool for discriminating between DNA lesions induced by different types of cytotoxic agents in cultured mammalian cells

The LA-D cells, obtained by cotransformation of LTA mouse cells (tk- aprt-) with pR plasmid and with tk gene as selective marker, are significantly more resistant to UV light and 4-nitroquinoline-N-1-oxide than LTA control cells. In this work, we report that the LA-D cells exhibit different degrees of response to various DNA-damaging agents: wild-type survival to mitomycin, increased sensitivity to bleomycin, cis-diamminedichloroplatinum and N-methyl-N'-nitro-N-nitrosoguanidine. The pR plasmid could, therefore, play an important role in the DNA-repair mechanisms that modulate the cytotoxic effect of the DNA-inhibitory agents. The possible interactions between pR plasmid products and the different repair enzymes involved are discussed.

Use of ceftazidime in the treatment of otorhinolaryngoiatric bacterial infections

Within the framework of an investigation into otorhinolaryngoiatric bacterial infections in Italy conducted in 1159 patients (607 with otitis media, 354 with pharyngo-tonsillitis and 198 with sinusitis), 124 ceftazidime-treated subjects (92 with otitis media, 22 with pharyngo-tonsillitis and 10 with sinusitis) were observed. The authors report the examination of a number of microbial isolates obtained in the various forms of otorhinolaryngoiatric bacterial infection. Gram-negative organisms were found as causative agents in such diseases, particularly in otitis media. Bacterial resistance to ceftazidime was assessed in all 1159 cases and proved relatively infrequent (3.6%) and markedly less than the detected resistance to other antibiotics (10.7% resistance to cefotaxime, 35% resistance to ampicillin, 43% resistance to penicillin). Ceftazidime, used mainly in otitis media, showed very substantial clinical efficacy with positive results in as many as 97% of cases treated, which is particularly significant, if one considers that roughly 64% of the infections were caused by "difficult" gram-negative bacteria (49% by Pseudomonas).