The enzymatic properties of Arabidopsis thaliana DNA polymerase λ suggest a role in base excision repair.

Base excision repair (BER) generates gapped DNA intermediates containing a 5'-terminal 2-deoxyribose-5-phosphate (5'-dRP) group. In mammalian cells, gap filling and dRP removal are catalyzed by Pol ß, which belongs to the X family of DNA polymerases. In higher plants, the only member of the X family of DNA polymerases is Pol λ. Although it is generally believed that plant Pol λ participates in BER, there is limited experimental evidence for this hypothesis. Here we have characterized the biochemical properties of Arabidopsis thaliana Pol λ (AtPol λ) in a BER context, using a variety of DNA repair intermediates. We have found that AtPol λ performs gap filling inserting the correct nucleotide, and that the rate of nucleotide incorporation is higher in substrates containing a C in the template strand. Gap filling catalyzed by AtPol λ is most efficient with a phosphate at the 5'-end of the gap and is not inhibited by the presence of a 5'-dRP mimic. We also show that AtPol λ possesses an intrinsic dRP lyase activity that is reduced by mutations at two lysine residues in its 8-kDa domain, one of which is present in Pol λ exclusively and not in any Pol ß homolog. Importantly, we also found that the dRP lyase activity of AtPol λ allows efficient completion of uracil repair in a reconstituted short-patch BER reaction. These results suggest that AtPol λ plays an important role in plant BER.

Infection control in long term care institutions for the elderly: A reflection document on the situation in Spain.

A progressively increasing percentage of the elderly live during the last years of their lives in nursing homes. Although these institutions are intended to mimic life at home as much as possible, they have characteristics that make them quite similar to a "nosocomiun", i.e. an establishment for the treatment of the sick. The very coexistence among the elderly, the fact of sharing caregivers and the very significant exposure to third parties, together with the frequent predisposing diseases to infection in this population, make infection frequent among residents and also easily transmissible. This leads us to ask what can be done to prevent infection in this environment and more specifically what is the state of the art of the matter in a Western European nation such as ours. The Board of Trustees of the Health Sciences Foundation has asked itself a series of questions on the subject of infection prevention in Nursing Homes, the structure of procedures, the legislation available, compliance with the measures indicated, the best indicators of the processes and therefore, the need to promote in Spain a document of recommendations to avoid infections in this poplation whose morbidity and mortality need not be highlighted. To this end, a multidisciplinary group of experts in different aspects of this problem has been convened and asked the proposed questions. The questions were discussed by the group as a whole and led to a series of conclusions agreed upon by the participants. The results of the meeting are reported below.

Left subclavian artery pseudoaneurysm after a traffic accident: a case report.

The left subclavian artery pseudoaneurysm is a rare entity with few cases reported in the literature. Most injuries were related to iatrogenic manipulation with catheters for canalization of central lines. In rare cases, this injury has been described secondary to a blunt trauma. We present an unusual case of pseudoaneurysm that includes the origin of left subclavian artery in the context of severe multiple injuries after a traffic accident. There were not clavicular or rib fractures, or another type of chest trauma to justify such a vascular injury. Once the injuries that were life threatening for the patient were stabilized, it proceeded to the treatment of the pseudoaneurysm by placing an endovascular prosthesis successfully with a favorable clinical evolution.

Neuroblastoma in adolescents: genetic and clinical characterisation

BACKGROUND: Age at diagnosis is an important risk factor in neuroblastoma (NB) with worse prognosis in children older than 18 months. A more indolent course with long-term relapses and fatal outcome has been described in small series of adolescents. Our objective was to describe biological factors that contribute to this particular behaviour and could be helpful in their treatment. PROCEDURE: NB cases older than 10 years of age at diagnosis registered in the files of the Neuroblastoma Group of SEOP from 1992 to 2007 were included. Disease extension was classified according to the International Neuroblastoma Staging System (INSS). Tumour samples were studied according to the International Neuroblastoma Pathology Classification (INPC). Biological studies included MNA, 1p, 11q and 17q status and ploidy. RESULTS: Twenty-two patients, from 10.1 to 24.6 years old, were included. Advanced stages predominated. 14/17 patients presented unfavourable histology. None had NMA or 1p del. However, 11q del was found in 8/13 cases and 17q gain in 7/11. Overall survival (OS) and event-free survival (EFS) for the entire series at 5 years were 0.45 and 0.32, respectively. Moreover, 5-year OS and EFS for stage 4 patients were 0.33 and 0.15. CONCLUSIONS: NB in adolescents is a special subgroup characterised by high-risk prognostic features which differ from those seen in younger patients, especially in relation to genetic abnormalities. The outcome in stage 4 was worse than in younger metastatic children, outlining the need for new therapeutic approaches in this subgroup of patients. The exact cut-off to separate older patients has not yet been established and will probably be based on biology (AU)

Long-term results of the Spanish Protocol SO-95 for the treatment of non-metastatic high-grade osteosarcoma of the extremities in children

INTRODUCTION: The long-term results of the Spanish Study Protocol SEOP-SO-95 for treatment of localised osteosarcoma of the extremities in children were evaluated. PATIENTS AND METHODS: One hundred consecutive patients under 18 years of age from 22 institutions were enrolled from January 1995 to December 2000. Immunohistochemical expression of p53, HER/erbB-2 and P-glycoprotein were retrospectively studied in 27 patients. Treatment consisted of: preoperative chemotherapy with doxorubicin, cisplatin, high-dose methotrexate with leucovorin rescue and ifosfamide for 14 weeks; surgery of primary tumour in week 16; postoperative chemotherapy with the above-mentioned drugs for 25 weeks. RESULTS: With a median follow-up of 124 months (range 84-158 months), 69 patients (69%) were continuously event-free survivors; the 10-year probability of event-free survival (EFS) was 62%. Conservative surgery was performed in 85% of patients. Twenty-six patients had local recurrence or distant relapse. The median time to recurrence/ relapse was 27 months (range 17-93 months). The local recurrence rate was 7% (7 of the 100 patients); 4 had wide surgical margins, 2 marginal and 1 intralesional. Four patients died as a result of chemotherapy-related toxicity and 1 developed a second neoplasia (acute myeloid leukaemia). p53 expression and HER2/erbB-2 expression showed no effect on survival or EFS. CONCLUSIONS: This therapeutic protocol achieved good oncologic and orthopaedic results. We observed a significant treatment-related toxicity (AU)

Studies on thiamine diphosphate-dependent enzymes.

The 3-deaza analogue of TPP (thiamine diphosphate), a close mimic of the ylid intermediate, has been synthesized and is an extremely potent inhibitor of a variety of TPP-dependent enzymes, binding much more tightly than TPP itself. Results using deazaTPP complexed with the E1 subunit of PDH (pyruvate dehydrogenase) have led to a novel proposal about the mechanism of this enzyme. The 2-substituted forms of deazaTPP, which mimic other intermediates in the catalytic mechanism, can also be synthesized and 2-(1-hydroxyethyl)deazaTPP is also an extremely potent inhibitor of PDC (pyruvate decarboxylase). Attachment of such 2-substituents is expected to be a way to introduce selectivity in the inhibition of various TPP-dependent enzymes.

Prenatal detection of a paracentric inversion 16(q11.2q13).

We report the prenatal detection of an inherited paracentric inversion 16(q11.2q13).

Outcome of high-risk neuroblastoma using a dose intensity approach: improvement in initial but not in long-term results.

BACKGROUND: Stage 4 and MYCN amplified (MNA) neuroblastoma in children have a poor prognosis. Our aim was to increase initial and long-term response in this population. PROCEDURE: High-risk children were studied according to the International Neuroblastoma Staging System, then treated with high-dose cyclophosphamide and high-dose carboplatin, followed by surgery and autologous stem cell transplant or maintenance chemotherapy. RESULTS: From June 1992 to December 1998, 83 children were admitted in the study (72 stage 4> 1 year, 5 stage 4 MNA infants, and 6 MNA stage 3 children); tumor tissue was obtained from 73, MYCN was performed in 65, being amplified in 21 (32%). Induction chemotherapy was administered in the expected time in 35% of patients. Its toxicity was mainly hematologic followed by infections, and there were 3 chemotherapy-related deaths. Delayed surgery was performed on 60 patients with complete or >90% resection in 80% of cases. Chemotherapy plus surgery produced some response in 90% of patients, 53% were in CR/VGPR; 49 children received autologous SCT, and 16 received maintenance chemotherapy for 9 months. Follow-up ranges are 1-87 months, mean 30 months. S and EFS at 4 years are 0.33 (SD 0.02). CONCLUSIONS: High-dose cyclophosphamide and high-dose carboplatin are effective in the initial treatment of neuroblastoma; combined with surgery they produce some response in most patients. Nevertheless, the CR/VGPR rate reaches only 53%. Survival time has also been prolonged but most patients relapse with metastases.

Results of the cooperative protocol (N-III-95) for metastatic relapses and refractory neuroblastoma.

BACKGROUND: Prognosis of relapsed and refractory neuroblastoma is uniformly fatal; new therapeutic approaches are needed. PROCEDURE: Relapsed and refractory neuroblastoma patients were treated with continuous infusion chemotherapy combined with MIBG. RESULTS: Over 4 years, 35 heavily pretreated patients were registered, 29 with bone or/and bone marrow metastases. Grade 3 or 4 hematologic toxicity was frequent, without toxic deaths. Sixteen patients responded. The probability of 5-year overall survival was 0.19. CONCLUSIONS: This approach is feasible and toxicity manageable; it rescued some patients and prolonged their survival. It merits assay in newly diagnosed high-risk neuroblastoma patients.

Prospective evaluation of the International Neuroblastoma Staging System (INSS) and the International Neuroblastoma Response Criteria (INRC) in a multicentre setting.

The aim of this study was to classify prospectively a series of neuroblastoma tumours according to the International Neuroblastoma Staging System (INSS) and the International Neuroblastoma Response Criteria (INRC) and to evaluate the difficulties and pitfalls involved in a multicentre setting. Each hospital provided their data for central review. The surgical procedures and their complications were reported. Kaplan-Meier estimates of survival and event-free survival were calculated according to stage and response to therapy. From June 1992 to December 1996, 194 patients were included in the study, with a mean age of 2 years. Initial studies were performed according to INSS recommendations without major problems. INSS stage was correctly applied to all patients except for 9 (95%). Post-operative complications were observed in 15 patients (8.3%). Response to therapy (INRC) was studied in 63 stage 4 patients, 11 of whom were not classified correctly (17%). Differences in survival according to stage (INSS) and group of response to therapy (INRC) were statistically significant (P < 0.001). In conclusion the INSS was easy to use and separated different prognostic groups. Surgical complications and mortality did not increase in this series because of using the INSS. The feasibility of INRC was evaluated in a small series of stage 4 patients and the designation of response was problematic in a relatively high proportion of cases. The prognostic value of the different responses was highly significant, but less informative than had been hoped for.

Synthesis and inotropic activity of hydroindene derivatives.

A synthetic approach to hydroindenic inotropic agents has been developed, starting from enantiopure Hajos-Parrish (1). Hajos-Wiechert (2), and related diketones. Their transformation into C-1 formyl derivatives and other subsequent synthetic targets is described. The results of the thermodynamic equilibration between both epimers of each formyl derivative are analysed. The inotropic activities of selected compounds on right and left atrial preparations are also evaluated and discussed.

Hydroindenic-guanylhydrazones. Synthesis and evaluation as inotropic agents.

The synthesis and inotropic activity of two families of hydroindenic compounds are described. Among them, a bis-guanylhydrazone derivative has demonstrated to produce an interesting positive inotropic effect on guinea pig atria, displaying at higher dosis a similar effect to that elicited by digoxin.

Treatment of stage III neuroblastoma with emphasis on intensive induction chemotherapy: a report from the Neuroblastoma Group of the Spanish Society of Pediatric Oncology.

From October 87 to April 92, 172 children were admitted in the N-I-87 protocol of the Spanish Society of Pediatric Oncology for the diagnosis and treatment of neuroblastoma. Forty-eight were considered Evans stage III, 33 of them being older than 1 year. All children were treated with induction chemotherapy (IC) and surgery. IC consisted of three courses of high-dose cisplatin-VM-26 alternating with three further courses of cyclophosphamide-doxorubicin (CAD). Infants less than 1 year received the same drugs at lower doses. After surgery, maintenance chemotherapy was administered to all children during 14 months. It consisted of four pairs of drugs rotated every 4 weeks. Radiotherapy was administered exclusively to patients older than 1 year with residual tumor after IC and surgery. Response was evaluated after IC and surgery. In children older than 1 year, response was obtained in 28/33 (88%). Fifteen of them (47%) achieved complete remission (CR), seven (22%) good partial response (GPR), six (19%) partial response (PR); and in three patients (9%) there was progressive disease (PD). Actuarial survival at 48 months was 0.60 +/- 0.10 and EFS was 0.61 +/- 0.12. Audiologic impairment was considered the worst toxicity. In children less than 1 year the response rate to IC and surgery was 93% (14/15); nine infants obtained complete response and four had GPR. Only one patient experienced PD in the first 6 months of therapy and died. The other 14 are alive and well at a mean follow-up time of 48 months. Chemotherapy toxicity was mild and reversible.