G2 checkpoint-dependent DNA repair and its response to catalase in Down syndrome and control lymphocyte cultures

The amount of DNA lesions repaired in G2 and also G2 timing are controlled by the DNA damage-dependent checkpoint. Down syndrome (DS) lymphocytes showed twice as much constitutive DNA damage in G2 than control ones, when recording it as chromosomal aberrations in metaphase, after caffeine-induced checkpoint abrogation. During G2, DS lymphocytes repaired 1.5 times more DNA lesions than control ones. However the DS cells displayed a decreased threshold for checkpoint adaptation, as the spontaneous override of the G2 to mitosis transition block induced by the checkpoint took place in the DS cells when they had three times more DNA lesions than controls. Catalase addition to cultures scavenges hydrogen peroxide diffused from cells, resulting in subsequent intracellular depletion (Antunes and Cadenas, 2000). The intracellular H2O2 level seemed to regulate the G2 checkpoint. Thus, in controls, H2O2 depletion (induced by 3.2-50 microg/mL catalase) prevented its functioning: chromosomal damage increased while G2 shortened. Conversely, in the DS lymphocytes, 12.5 microg/mL catalase lengthened G2 and decreased chromosomal damage, in spite that the amount of DNA repaired in G2 was half of that repaired in the catalase-free DS lymphocytes.

Deficit irrigation and rootstock: their effects on water relations, vegetative development, yield, fruit quality and mineral nutrition of Clemenules mandarin

Differences between rootstocks, 'Cleopatra' mandarin and 'Carrizo' citrange, in soil-plant water relations and the influence of these factors on vigor, crop yield, fruit quality and mineral nutrition were evaluated in field-grown Clemenules mandarin trees irrigated at 100% of potential seasonal evaporation (ET(c)) (control treatment), or irrigated at 100% ET(c), except during Phases I and III of fruit growth and post-harvest when no irrigation was applied (deficit irrigation (DI) treatment), for 3 years. Differences between rootstocks in plant-soil water relations were the primary cause of differences among trees in vegetative development and fruit yield. After 3 years of DI treatment, trees on 'Cleopatra' showed more efficient soil water extraction than trees on 'Carrizo', and maintained a higher plant water status, a higher gas exchange rate during periods of water stress and achieved faster recovery in gas exchange following irrigation after water stress. The DI treatment reduced vegetative development more in trees on 'Carrizo' than in trees on 'Cleopatra'. Cumulative fruit yield decreased more in DI trees on 'Carrizo' (40%) than on 'Cleopatra' (27%). The yield component most affected by DI in 'Cleopatra' was the number of fruit, whereas in 'Carrizo' it depended on the severity of water stress reached in each phase (severe water stress in Phase I affected mainly the number of fruit, whereas it affected fruit size the most in Phase III). In the third year of DI treatment, water-use efficiency decreased sharply in trees on 'Carrizo' (70%) compared to trees on 'Cleopatra' (30%). Thus, trees on 'Cleopatra' were able to tolerate moderate water stress, whereas trees on 'Carrizo' were more sensitive to changes in soil water content.

Étude comparative de la vitrectomie transconjonctivale sans suture à 25-gauges avec celle à 20-gauges

PURPOSE

The transconjunctival sutureless vitrectomy (TSV 25) is a new technique showing substantial progress.

METHODS

A prospective study of 66 eyes of 66 patients who underwent surgical procedures using the transconjunctival standard vitrectomy system (TSV 25), between June 2004 and June 2005. The results were compared with the results in an equivalent population (66 patients) that underwent vitrectomy with a standard 20-gauge system.

RESULTS

The most important differences between groups were 1) shorter surgical time in the 25-gauge vitrectomy group than in the 20-gauge group, with a mean time of 28.15+/-5.50 min for group 1 and 44.15+/-5.64 min for group 2 (p<0.001) and 2) lower mean postoperative intraocular tension in the first group of patients: in this group, the intraocular tension before surgery was a mean of 16.27+/-1.76 mmHg, decreasing to 12.17+/-1.36 mmHg, with a posterior increase to normal values of 15.06+/-1.66 mmHg at 7 days after surgery and a mean of 16.10+/-1.51 mmHg at 15 days. This decrease was not observed in the group of patients who underwent 20-gauge vitrectomy surgery. The other postoperative complications were similar in both groups except for four cases of anterior proliferation and two cases of fibrinous uveitis in group 2.

CONCLUSION

The transconjunctival sutureless system (TSV 25) decreases surgical time and postoperative inflammation, with optimal postoperative patient comfort, but currently the accurate selection of patients remains important.

Chirurgie combinée phacoexérèse, vitrectomie et implantation chez le patient diabétique avec phacoémulsification versus phacophragmentation

INTRODUCTION

In diabetic patients, we often need to perform cataract and pars plana vitrectomy. Two different techniques are currently valid: 1) phacoemulsification and pars plana vitrectomy and 2)pars plana lensectomy and posterior vitrectomy.

METHODS

Retrospective study of two different groups of type 2 diabetic patients: those receiving 1) phacoemulsification and pars plana vitrectomy or 2) pars plana lensectomy and posterior vitrectomy.

RESULTS

On statistical analysis there were no differences in complications between the two groups. The effect on visual acuity was similar in both groups.

DISCUSSION

The association of cataract surgery and posterior vitrectomy is a valid technique for treating diabetic retinopathy complications. In the present study, the complications of the two techniques were similar, the most important concerning only anterior chamber opening in the first group.

CONCLUSION

The two techniques of cataract extraction and pars plana vitrectomy at the same time have no differences in their results and are valid for treatment of diabetic patients.

Épithéliopathie pigmentaire rétinienne diffuse et traitement topique avec pommade à base de corticostéroïdes dans un cas de psoriasis

Central serous chorioretinopathy has three patterns: the first or typical form with one or several points of diffusion; the second, diffuse retinal pigment epitheliopathy; and the third, the bullous form of serous chorioretinopathy. The authors present a case of a 55-year-old male presenting with diffuse retinal pigment epitheliopathy and topical treatment of psoriasis, with a 9-year history of corticoid ointment use, associated with cyclosporine over the last year. The topical treatment was discontinued and the patient recovered his vision, with a final visual acuity of 5/10 in the right eye and 4/10 in the left eye.

Optimum in vitro expansion of human antigen-specific CD8 T cells for adoptive transfer therapy

Increasing evidence suggests that adoptive transfer of antigen-specific CD8(+) T cells could represent an effective strategy in the fight against chronic viral infections and malignancies such as melanoma. None the less, a major limitation in the implementation of such therapy resides in the difficulties associated with achieving rapid and efficient expansion of functional T cells in culture necessary to obtain the large numbers required for intravenous infusion. Recently, the critical role of the cytokines interleukin (IL)-2, IL-7 and IL-15 in driving T cell proliferation has been emphasized, thus suggesting their use in the optimization of expansion protocols. We have used major histocompatibility complex (MHC) class I/peptide multimers to monitor the expansion of antigen-specific CD8 T lymphocytes from whole blood, exploring the effect of antigenic peptide dose, IL-2, IL-7 and IL-15 concentrations on the magnitude and functional characteristics of the antigen-specific CD8(+) T cells generated. We show here that significant expansions of antigen-specific T cells, up to 50% of the CD8(+) T cell population, can be obtained after a single round of antigen/cytokine (IL-2 or IL-15) stimulation, and that these cells display good cytolytic and interferon (IFN)-gamma secretion capabilities. Our results provide an important basis for the rapid in vitro expansion of autologous T cells from the circulating lymphocyte pool using a simple procedure, which is necessary for the development of adoptive transfer therapies.

The 2001 epidemic of foot-and-mouth disease in the United Kingdom: epidemiological and meteorological case studies

The possibility of the airborne spread of foot-and-mouth disease during the 2001 epidemic in the uk has been investigated in three epidemiological case studies. On the basis of evidence from field investigations, and a simple meteorological analysis, it is concluded that the spread of disease was consistent with the airborne transport of virus. The distances ranged from less than 1 km to 16 km; six of the farms were over 6 km from the source and involved the passage of virus over the sea combined with meteorological conditions which strongly favoured airborne disease transmission. The results of detailed atmospheric modelling demonstrated that airborne virus could have challenged livestock on all the farms studied. However, with one exception the 24-hour average daily concentrations of the virus were significantly below the experimentally estimated threshold for infection. A detailed model intercomparison established that, under stable atmospheric conditions, peak concentrations of virus up to two orders of magnitude higher might have been experienced for short periods, owing to fluctuations within the plume of virus, and model limitations. This finding would significantly reduce the apparent discrepancy between the experimentally estimated threshold for infection and the modelling results.

[Veracity of smokers' reports of abstinence at smoking cessation clinics]

OBJECTIVE

To assess the reliability of smokers' response as criteria for measuring abstinence and the necessity or not of confirming abstinence with carbon monoxide (CO) measurement.

PATIENTS AND METHODS

A multicenter, prospective, longitudinal study was carried out on patients over 18 years of age from 5 smoking cessation clinics who underwent treatment with nicotine or bupropion. When the patient attended the clinic at 15, 30, 60, 90, and 180 days, abstinence was checked by self-reporting and expired-air CO levels. Sensitivity, specificity, and positive, negative, and overall predictive value of patient reporting, measured CO levels, and the 2 procedures in combination were calculated.

RESULTS

A total of 904 smokers (476 men and 428 women) with a mean (SD) age of 42.51 (10.09) years were enrolled in the study. Of the 904 patients that made up the study population, 820, 776, 687, 719, and 679, respectively, attended the scheduled visits to check abstinence. Self-reported point-prevalence abstinence at 15 days was 74.5% and at 180 days was 57.6% while abstinence determined by expired-air CO was 75.7% and 59.4% respectively. Results according to self-reporting, CO measurement, and the 2 methods in combination were not significantly different (P<.05) at any of the points in time. Neither sensitivity nor specificity showed significant differences in relation to patient variables.

CONCLUSION

The reliability of self-reported abstinence from smoking is high. Measurement of CO is therefore not essential, although it could be advisable for motivating patients rather than as a way of confirming abstinence.

[Respiratory emergencies]

Respiratory emergencies in a patient with cancer can have their origin in pathologies of the airway, of the pulmonary parenchyma or the large vessels. The cause can be the tumour itself or concomitant complications. Obstruction of the airway should be initially evaluated with endoscopic procedures. Surgery is rarely possible in serious situations. The endobronchial placement of stents or radioactive isotopes (brachytherapy), tumoural ablation by laser or photodynamic therapy can quickly alleviate the symptoms and re-establish the air flow. Treatment of haemoptysis depends on the cause that is provoking it and on its quantity. Bronchoscopy continues to be the front line procedure in the majority of cases; it provides diagnostic information and can interrupt bleeding through washes with ice-cold serum, endobronchial plugging or topical injections of adrenaline or thrombin. External radiotherapy continues to be an extraordinarily useful procedure in treating haemoptysis caused by tumours and in carefully selected situations of endobronchial therapy with laser or brachytherapy, and bronchial arterial embolisation can provide a great palliative effect. Respiratory emergencies due to pulmonary parenchyma disease in the oncology patient can have a tumoural, iatrogenic or infectious cause. Early recognition of each of these will determine the administration of a specific treatment and the possibilities of success.

[Medullar compression]

Medullar compression is an oncological and neurological emergency, whose diagnosis and early treatment are key factors for avoiding severe and irreversible neurological damage. Paralysis, loss of consciousness and alteration in control of the sphincters are the final consequence of the process, and represent an important source of morbidity of the oncology patient, besides being related to a shorter time of survival. The invasion of the vertebral body by haematogenous dissemination is the most frequent cause of medullar compression. On occasions it can create mechanical vertebral instability which represents a real orthopaedic emergency. Pain is the earliest and most frequent symptom. The signs and symptoms appear to the degree that the process advances, passing through motor weakness, alterations in consciousness until paralysis and incontinence of the sphincters are reached, as a result of complete neurological damage. Clinical history and physical exploration should lead to suspicion about the level at which medullar compression is developing, and the most important complementary exploration is MR of the entire spine, which should be requested immediately in order to decide on starting treatment. Treatment is individualised and must be started early. In general, corticoids in combination with radiotherapeutic oncological treatment and/or surgery are the therapeutic weapons to employ.

[Acute dysphagia of oncological origin. Therapeutic management]

Dysphagia is one of the most frequent syndromes in patients with tumours of the head and neck, and the oesophagus. This can be the initial symptom or, more frequently, related to the oncological treatment. We review the most important therapeutic and physio-pathological aspects of acute dysphagia of oncological origin. Deglutition is a complex process in which numerous muscular-skeletal structures intervene under the neurological control of different cranial nerves. The complex neuro-muscular coordination needed for a correct deglutition can be affected by numerous situations, both from the effect of the tumours and from their treatment, basically surgery or radiotherapy. In conclusion, it can be affirmed that for a suitable treatment of oncological dysphagia, a correct initial evaluation and an active treatment are required, since not only the patient's quality of life but, on numerous occasions, the possibility of continuing the treatment and thus maintaining the possibilities of a cure depend on control of the dysphagia.

[Malign obstruction of the superior vena cava]

The present paper offers a review of the malign syndromes of the superior vena cava, their clinical expressions related to the anatomical characteristics of the compartment where the superior vena cava runs, the diagnostic requirements for realising treatment under the best conditions and the ensemble of measures that must be adopted in dealing with this.

[Metastatic bone disease. Diagnosis and treatment]

The high incidence of bone metastasis secondary to carcinomas and its serious functional repercussion are motives for constant study and advance in the methods of evaluation, diagnosis and treatment. Pain is the most frequently shown symptom, although at times the start is a pathological fracture. The classic tests of detection and evaluation of the spread of the metastatic disease, simple radiology and gammagraphy, are today complemented by others such as computerised tomography (CT) and magnetic resonance (MR), improving the information on the characteristics of the lesion both inside and outside the bone. On the other hand, positron emission tomography (PET) is showing a far higher sensitivity than gammagraphy and will probably be the test of the future for the early detection of metastasis and of silent primary tumours. The possibilities of treatment of bone metastasis are based on the use of bone regenerators, radiotherapy and surgery. The former two are indicated in lesions already detected in radiography, whether symptomatic or not, if there is no foreseeable risk of fracture. Surgery is indicated in situations of poor or null response to those treatments, when the risk of fracture is high or a pathological fracture has been produced. Before any therapeutic planning, a detailed evaluation of the patient must be carried out, both at a local level (size, site, extension of the metastasis) and general (type of primary tumour, phase of treatment and response, estimated survival).