Assessment of the natural sources of particulate matter on the opencast mines air quality

Particulate matter is the main air pollutant in open pit mining areas. Preferred models that simulate the dispersion of the particles have been used to assess the environmental impact of the mining activities. Results obtained through simulation have been compared with the particle concentration measured in several sites and a coefficient of determination R(2)<0.78 has been reported. This result indicates that in the open pit mining areas there may be additional sources of particulate matter that have not been considered in the modeling process. This work proposes that the unconsidered sources of emissions are of regional scope such as the re-suspension particulate matter due to the wind action over uncovered surfaces. Furthermore, this work proposes to estimate the impact of such emissions on air quality as a function of the present and past meteorological conditions. A statistical multiple regression model was implemented in one of the world's largest open pit coal mining regions which is located in northern Colombia. Data from 9 particle-concentration monitoring stations and 3 meteorological stations obtained from 2009 to 2012 were statistically compared. Results confirmed the existence of a high linear relation (R(2)>0.95) between meteorological variables and particulate matter concentration being humidity, humidity of the previous day and temperature, the meteorological variables that contributed most significantly in the variance of the particulate matter concentration measured in the mining area while the contribution of the AERMOD estimations to the short term TSP (Total Suspended Particles) measured concentrations was negligible (<5%). The multiple regression model was used to identify the meteorological condition that leads to pollution episodes. It was found that conditions drier than 54% lead to pollution episodes while humidities greater than 70% maintain safe air quality conditions in the mining region in northern Colombia.

Phase II study of bevacizumab and cetuximab as neoadjuvant treatment in locally advanced rectal cancer: A preliminary security report

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Background: Concurrent chemoradiotherapy is the standard treatment in locally advanced rectal cancer. Bevacizumab and cetuximab are accepted today in the treatment of metastatic colorrectal cancer. We evaluate the activity and security of these drugs in the neoadyuvante setting.

Methods: Ten patients have been included so far. Treatment consists in a first phase with induction treatment with capecitabine 2,000 mg/m2 D1-14, oxaliplatin 130 mg/m2 and bevacizumab 7.5 mg/kg every 3 weeks for two cycles. In sequential form a second phase that consist in external beam radiation therapy that was given at 50.4 Gy in 28 sesions concurrently with capecitabine 1,300 mg/m2 /d continuous during radiotherapy with cetuximab 400 mg/m2 every two weeks in patients with k-ras wild type.

Results: 10 patients completed induction treatment and eight patients completed the concurrent phase. As of today, two patients are still on treatment. At this point, four patients have been operated; three patients are still waiting for surgery, and one avoided surgery. During induction treatment the main toxicity was disesthesias in eight patients, four patient presented grade 2 emesis, two presented grade 2 altered liver function test, two had grade 2 hand foot syndrome. One patient presented grade 3 hemorrhage. During the second phase, eight patients received cetuximab and presented rash grade 1-2, diarrhea grade 1 in five patients, emesis grade 1 in four patients, anemia grade 2 in two patients, proctitis grade 2 in four patients, and grade 3 in one patient. From four patients who were operated two presented complete pathological response and two have tumor persistence.

Conclusions: The combination of chemoradiation with bevacizumab and cetuximab seems to be secure with no increment in toxicity and those presented are acceptable and manageable.

No significant financial relationships to disclose.

Capecitabine (X) and taxanes in patients (pts) with anthracycline-pretreated metastatic breast cancer (MBC): Sequential vs. combined therapy results from a MOSG randomized phase III trial

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Introduction: Capecitabine (Xeloda [X]) shows synergy with taxanes and adding X to docetaxel (T) extends overall survival (OS), response rate (RR) and progression free-survival (PFS) beyond T alone. Sequential single-agent therapy could confer convenience benefits and may be more appropriate than combination chemotherapy for some pts. Methods: Pts with anthracycline-pretreated MBC received 3-weekly cycles of 1 of the following regimens: X→taxane (X 1250mg/m2 bid d1–14, followed after progression (PD) by T 100mg/m2 or paclitaxel [P] 175mg/m2 day 1; X+P (X 825mg/m2 bid days 1–14 + P 175mg/m2 day 1) or X+T (X 825mg/m2 bid days 1–14 + T 75mg/m2 day 1). Results: Of the 368 pts enrolled, 91 are either still on therapy or not evaluable. The table shows baseline characteristics, efficacy and safety in evaluable pts. Median follow up is 15.5 months. Median doses for X in each arm (1st cycle vs. 8th cycle, mg/m2 bid): 1218 vs. 1054; 948 vs. 900; 846 vs. 751. Median doses for P and T (1st cycle vs. 8th cycle, mg/m2): 173 vs. 169 and 75 vs. 72, respectively. In the X→taxane arm, 58 pts (64%) received sequential taxane; the remainder did not receive a taxane, either because they were still on X, had CR or had rapid PD. Conclusions: RR is higher with XP and XT, but PFS and OS are similar at a median follow-up of 15.5 months. All regimens were well tolerated with minimal grade 4 AEs. Because there is no clear superiority of sequential vs. combined therapy, pt characteristics are likely to be used to decide which regimen is the most appropriate.

[Table: see text]

[Table: see text]

Pd(II) and Pt(II) complexes with aromatic diamines: study of their interaction with DNA

Pd(II) and Pt(II) new complexes with simple aromatic diamines were synthesised and characterised with the aim of studying their possible antitumour activity. The aromatic diamines chosen were 2,3-diaminotoluene (2,3 dat), 3,4-diaminotoluene (3,4 dat), 4,5-diaminoxylene (4,5 dax) and 2,3-diaminophenol (2,3 dap). The complexes, of formulae cis-[MCl(2)(diamine)], were characterised by elemental analysis, conductivity measurements, 1H, 13C(1H) and 195Pt NMR spectroscopy. The X-ray crystal structure was also resolved for the palladium complexes with 2,3-diaminotoluene and 4,5-diaminoxylene. The DNA adduct formation of the eight new complexes synthesised was followed by circular dichroism and electrophoretic mobility. Atomic force microscopy images of the modifications caused by the complexes on plasmid DNA pBR322 were also obtained. Values of IC50 were also calculated for the four platinum complexes against the cisplatin resistant tumour cell line A2780cisR.

Dichloro(d-methionine-n,s)platinum(ii) at 130 k

The asymmetric unit of the title compound, [PtCl2(C5H11NO2S)], a D-methionine derivative, contains two molecules with opposite chirality at the S atoms. The amino acid acts as a bidentate ligand and coordinates simultaneously through the N (amino) and S (thioether) atoms. The molecules are packed in pairs which are connected through two hydrogen bonds between the protonated carboxyl groups, with O.O distances of 2.633 (10) and 2.663 (12) A.

Induction of apoptosis by the bis-Pt(III) complex [Pt(2)(2-mercaptopyrimidine)(4)Cl(2)]

We analyzed both the cytotoxicity and the type of cell death produced by the novel binuclear Pt(III) compound Pt-Spym ([Pt(2)(2-mercaptopyrimidine)(4)Cl(2)]) in kidney human fibroblasts and in human tumor cell lines (HeLa, CH1, CH1cisR and HL-60). The data showed that Pt-Spym displayed higher cytotoxicity against these tumor cells than cisplatin. In contrast, Pt-Spym had low toxicity against normal human fibroblasts. Interestingly, Pt-Spym circumvented cisplatin resistance in CH1cisR cells. We also observed that Pt-Spym induced the characteristic changes attributed to apoptosis in cells with normal levels of p53 protein (CH1 and CH1cisR) and with low levels of p53 protein (HeLa), but not in cells lacking p53 (HL-60). Interestingly, Western blot data indicated that apoptosis induction by Pt-Spym in HeLa, CH1, and CH1cisR cells was not associated with drastic changes in p53 levels. However, cis-DDP strongly decreased p53 levels in CH1 and CH1cisR cells and abolish p53 protein in HeLa cells. Altogether, these results suggest that induction of apoptosis by Pt-Spym requires the presence of p53 protein.

DNA interaction and antitumor activity of a Pt(III) derivative of 2-mercaptopyridine

The complex [Pt2(Spy-)4Cl2], where Spy- is deprotonated 2-mercaptopyridine, was prepared and analyzed spectroscopically. A single signal in the 195Pt NMR spectrum indicates the equivalence of the two Pt(III) ions. The interaction of this complex with DNA was studied by circular dichroism and the modifications caused by the complex in plasmid pBR322 DNA were imaged by atomic force microscopy. Preliminary results showed higher activity against HeLa and U937 tumor lines for the Pt-2-mercaptopyridine complex in comparison with cisplatin. The values of LC50 were lower than those obtained for cisplatin. Promising perspectives for this compound are expected due to its similarity with the analogous Pt and 2-mercaptopyrimidine antitumor compound.

Study of the interaction of DNA with cisplatin and other Pd(II) and Pt(II) complexes by atomic force microscopy

Modifications in the structure of a 260 bp DNA (hlyM) fragment from Escherichia coli caused by interaction with Pd(II) and Pt(II) complexes were studied. Cisplatin and transplatin [cis- and trans-PtCl2(NH3)2 respectively], Pt2Cl2(Spym)4 (Spym = 2-mercaptopyrimidine anion), Pd-famotidine and Pt-famotidine were incubated with DNA for 24 h at 37 degrees C and then observed with an atomic force microscope. Atomic force microscopy (AFM) provides the opportunity for nanometer resolution in research on the interaction between nucleic acids and metal complexes. The complexes induced noticeable changes in DNA topography according to their different characteristics and structure. In the case of cisplatin a shortening in DNA strands was observed. Transplatin and Pt2Cl2(Spym)4 caused shortening and compaction, whilst an aggregation of two strands was observed for the Pt-famotidine compound but not for the Pd-famotidine compound or the metal-free famotidine.

Persistence of human papillomavirus DNA in cervical lesions after treatment with diathermic large loop excision

OBJECTIVE

The aim of this study was to identify human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and to evaluate the persistence of viral DNA after diathermic large loop excision (DLLE) treatment.

STUDY DESIGN

Biopsies from 36 patients with low- and high-grade CIN lesions were studied before and after DLLE treatment looking for HPV sequences. DNA was extracted to perform a radioactive polymerase chain reaction (PCR) using GP 5,6 generic primers. PCR products were analyzed by the single-stranded conformational polymorphism (SSCP) which is a simultaneous detection and typing method. Dot-blot hybridization with generic and type-specific biotinylated oligonucleotide probes was applied in some cases.

RESULTS

HPV DNA was found in all pretreatment samples, and the viral type was identified in 80% of them, HPV 16 being the most prevalent. The viral type coincided with that detected in the first biopsy in all except one case. Seventy five percent of the patients (27 cases) were negative for CIN at follow up, but 50% of them remained HPV DNA positive.

CONCLUSION

DLLE treatment was effective in removing the CIN lesion but not the HPV. This fact points out the need to asses the presence of HPV in DNA during the follow-up, since viral persistence has been considered a high risk factor for recurrence and/or malignant transformation.

Persistence of human papillomavirus DNA in cervical lesions after treatment with diathermic large loop excision

OBJECTIVE

The aim of this study was to identify human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and to evaluate the persistence of viral DNA after diathermic large loop excision (DLLE) treatment.

STUDY DESIGN

Biopsies from 36 patients with low- and high-grade CIN lesions were studied before and after DLLE treatment looking for HPV sequences. DNA was extracted to perform a radioactive polymerase chain reaction (PCR) using GP 5,6 generic primers. PCR products were analyzed by the single-stranded conformational polymorphism (SSCP) which is a simultaneous detection and typing method. Dot-blot hybridization with generic and type-specific biotinylated oligonucleotide probes was applied in some cases.

RESULTS

HPV DNA was found in all pretreatment samples, and the viral type was identified in 80% of them, HPV 16 being the most prevalent. The viral type coincided with that detected in the first biopsy in all except one case. Seventy five percent of the patients (27 cases) were negative for CIN at follow up, but 50% of them remained HPV DNA positive.

CONCLUSION

DLLE treatment was effective in removing the CIN lesion but not the HPV. This fact points out the need to asses the presence of HPV in DNA during the follow-up, since viral persistence has been considered a high risk factor for recurrence and/or malignant transformation.

Persistence of human papillomavirus DNA in cervical lesions after treatment with diathermic large loop excision

OBJECTIVE

The aim of this study was to identify human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and to evaluate the persistence of viral DNA after diathermic large loop excision (DLLE) treatment.

STUDY DESIGN

Biopsies from 36 patients with low- and high-grade CIN lesions were studied before and after DLLE treatment looking for HPV sequences. DNA was extracted to perform a radioactive polymerase chain reaction (PCR) using GP 5,6 generic primers. PCR products were analyzed by the single-stranded conformational polymorphism (SSCP) which is a simultaneous detection and typing method. Dot-blot hybridization with generic and type-specific biotinylated oligonucleotide probes was applied in some cases.

RESULTS

HPV DNA was found in all pretreatment samples, and the viral type was identified in 80% of them, HPV 16 being the most prevalent. The viral type coincided with that detected in the first biopsy in all except one case. Seventy five percent of the patients (27 cases) were negative for CIN at follow up, but 50% of them remained HPV DNA positive.

CONCLUSION

DLLE treatment was effective in removing the CIN lesion but not the HPV. This fact points out the need to asses the presence of HPV in DNA during the follow-up, since viral persistence has been considered a high risk factor for recurrence and/or malignant transformation.

Chronic myelocytic leukemia in accelerated phase with i(17) (q10) and loss of p53 gene. Case report

Chronic myelogenous leukemia (CML) is a clonal disorder that presents with a stable period followed by an accelerated phase. The most frequent chromosomal abnormality described is t(9;22). Alterations of chromosome 17, where p53 is located, have been described during transformation. We studied a 23-year-old male who presented with chronic myelogenous leukemia. The karyotype demonstrated 46,XY,t(9;22) (q34;q11) in 12% of mitoses and hyperdiploidy in 43%. Forty-six months later the patient suffered a blast crisis characterized by absolute basophilia; the cytogenetic study demonstrated 48,XY,+8,t(9;22) (q34;q11), +der(22)t (9;22) (q34;q11), +i(17)(q10) in 18% of the mitoses, 46,XY, t(9;22) (q34;q11) in 34% and hyperdiploidy in 23%. Since there was i(17)(q10) during this stage, a retrospective DNA study of the biopsy material before and after the transformation was performed. In the chronic phase, p53 was present in normal amounts, during transformation there was loss of genetic material from the p53 region. The protein product of suppressor gene p53 normally works holding the proliferation of cells. When there is the formation of an isochromosome, genetic material is lost; thus, in this patient, p53 was deleted upon the observation of i(17). Lastly, this case shows how DNA can be extracted from slides; this technique is novel and can be used for retrospective studies when paraffin blocks or fresh tissue are not available.

Results of a randomized study of previously-untreated intermediate and high grade lymphoma using CHOP versus CNOP

A randomized multicenter phase III study was conducted to compare the efficacy and toxicity of CHOP and CNOP in intermediate and high-grade non-Hodgkin's lymphoma. CHOP consisted of cyclophosphamide 750 mg/m2, vincristine 1.4 mg/m2, doxorubicin 50 mg/m2 on day 1 and prednisone 50 mg/m2 on days 1 to 5. The CNOP regimen was identical to CHOP except for replacement of doxorubicin by 10 mg/m2 mitoxantrone. Patient characteristics were evenly distributed in the two arms, except for age and stage, which slightly favoured the CHOP arm. The rate of complete remission was 70% (31/44) in patients treated with CHOP and 51% (23/45) in those receiving CNOP (P = 0.09). At 48 months and with a median follow-up of 41 months, 44% of the complete responders treated with CHOP and 64% of those treated with CNOP were estimated to still be in their first complete remission (P = 0.14), while 31% and 34% remained alive and free of progression. The Kaplan-Meier estimate of overall survival at 48 months is 53% and 50%, respectively. The higher response rate obtained with CHOP probably reflected a less aggressive lymphoma population. The mean WBC nadir was 2.0 x 10(9)/l for CHOP and 1.8 x 10(9)/l for CNOP. One and three patients, respectively, died during induction. Nausea, vomiting and cardiac toxicity were similar. More alopecia and mucositis were observed with CHOP. We conclude that CHOP and CNOP have similar toxicities and are equivalent in previously untreated non-Hodgkin's lymphoma in terms of complete response rate, event-free survival and overall survival.

Constitutional translocation (8;13) in a patient with non-Hodgkin's lymphoma

We report a case of non-Hodgkin's lymphoma in a 16-year-old male, whose peripheral white blood cells have a t(8;13)(q24;q14). There are no previous reports that describe this association. Although the tumor cells were not studied, we discuss the possible link between this finding and the development of the malignant lymphoma.

Cat endothelial morphology after corneal transplant

The cat has been suggested as a superior model to evaluate penetrating keratoplasty and corneal endothelial damage and repair. Morphologic change is felt to be a sensitive indicator of endothelial stress response. We documented corneal thickness and endothelial morphometric parameters of eight cats before and after homograft penetrating keratoplasty using an Eisner contact glass. One-hundred-cell samples from preoperative and 6.18 +/- 0.57 weeks and 9.25 +/- 0.84 months (means +/- standard errors of the means) postoperative photomicrographs were computer analyzed. Cell density (cells/mm2), coefficient of variation of cell area, percent hexagonal cells, and mean figure coefficient were measured. Values are given as means +/- standard errors of the means. Preoperative coefficient of variation for area, 19.1 +/- 0.4, was significantly greater (22.0 +/- 1.0) six weeks after surgery. At nine months, cell density (1487 +/- 114) and percent hexagonal cells (59.6 +/- 2.1) were significantly less than six week values (cell density = 2053 +/- 201, percent hexagonal cells = 68.1 +/- 1.5) and preoperative values (cell density = 2395 +/- 94, percent hexagonal cells = 69.3 +/- 1.1). Thus there is evidence of polymegethism six weeks after surgery and persistent decreased cell density and pleomorphism nine months after surgery.

Lack of relationship between lactose absorption and senile cataracts

In a double-blind study using the hydrogen breath-excretion test to identify lactase status, we found 45% of absorbers in a group of 64 patients with senile cataracts compared with 71% of absorbers in the control group. These results oppose the hypothesis that lactose absorbers are especially prone to develop senile cataracts.

Retinal vasculitis in mixed connective tissue disease. A fluoroangiographic study

The eyes of 20 consecutive patients with mixed connective tissue disease (MCTD) were studied by ophthalmologic and retinal fluoroangiographic examinations (RFA) and compared with the findings in 18 consecutive patients with primary Sjögren's syndrome (SS) and 50 with systemic lupus erythematosus (SLE). Six of the 20 MCTD patients had abnormal RFA with thickening of capillary walls that stained and progressively leaked fluorescein. None of these lesions could be seen in ophthalmoscopy, where only one patient had cotton wool spots that in RFA were found to correspond to focal areas of ischemia, probably resulting from capillary lesions. Only one patient with primary SS showed capillary leakage, whereas 13 patients with SLE had RFA abnormalities that included microaneurysms in 9, capillary lesions in 6 and drusen in one. No microaneurysms were found in MCTD patients. The differences between MCTD, SLE and SS patients may reflect differences in the quality, quantity, frequency and chronicity of immune complex formation and deposition in these 3 diseases.