Ultrastructural and mineral phase characterization of the bone-like matrix assembled in F-OST osteoblast cultures.

Cell cultures are often used to study bone mineralization; however, not all systems achieve a bone-like matrix formation. In this study, the mineralized matrix assembled in F-OST osteoblast cultures was analyzed, with the aim of establishing a novel model for bone mineralization. The ultrastructure of the cultures was investigated using scanning electron microscopy, atomic force microscopy, and transmission electron microscopy (TEM). The mineral phase was characterized using conventional and high-resolution TEM, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and solid-state (31)P and (1)H nuclear magnetic resonance. F-OST osteoblast cultures presented a clear nodular mineralization pattern. The chief features of the mineralizing nodules were globular accretions ranging from about 100 nm to 1.5 µm in diameter, loaded with needle-shaped crystallites. Accretions seemed to bud from the cell membrane, increase in size, and coalesce into larger ones. Arrays of loosely packed, randomly oriented collagen fibrils were seen along with the accretions. Mineralized fibrils were often observed, sometimes in close association with accretions. The mineral phase was characterized as a poorly crystalline hydroxyapatite. The Ca/P atomic ratio was 1.49 ± 0.06. The presence of OH was evident. The lattice parameters were a = 9.435 Å and c = 6.860 Å. The average crystallite size was 20 nm long and 10 nm wide. Carbonate substitutions were seen in phosphate and OH sites. Water was also found within the apatitic core. In conclusion, F-OST osteoblast cultures produce a bone-like matrix and may provide a good model for bone mineralization studies.

Endometriosis progression in tumor necrosis factor receptor p55-deficient mice: Impact on oxidative/nitrosative stress and metallomic profile.

The present study was conducted to investigate whether the deficiency of tumor necrosis factor receptor p55 (TNFRp55) modulates oxidative/nitrosative stress and metallomic profile into the peritoneal cavity during the experimental endometriosis progression in mice. Female C57BL/6 mice, wild-type (WT) and TNFRp55 knockout (KO) of two months were used. Endometriosis was induced experimentally by autotransplanting three pieces of the right uterine horn to the intestinal mesentery. After four weeks, endometriotic-like lesions and peritoneal lavage fluid were collected. The obtained peritoneal fluid was analyzed for nitrite levels using the Griess method and trace elements concentrations by ICP-MS. Both endometriotic-like lesions and cells isolated from peritoneal lavage were analyzed for the following oxidative/nitrosative stress markers: inducible nitric oxide synthase (iNOS) expression by Western Blot; total antioxidant capacity (TAC), the activity of two antioxidant enzymes (CAT and GPX) and thiobarbituric acid-reactive substances (TBARS) concentration, by spectrophotometric method; and protein carbonyl content and nitrotyrosine presence by ELISA. In comparison to WT group, KO mice exhibited larger lesion volume; higher levels of nitrite, copper (Cu) and strontium (Sr) in the peritoneal fluid; increased TAC, CAT, and GPX in peritoneal lavage cells; decreased concentration of TBARS in lesions and protein carbonyl in peritoneal lavage cells. Significant positive correlations between Cu and lesion volume, Sr and lesion volume, and Cu and Sr were obtained. Our results suggest that the TNFRp55 deficiency increases antioxidant protection and promotes high Cu-Sr concentrations in the peritoneal cavity, which favors the progression of experimental endometriosis.

The use of biosimilar medicines in oncology - position statement of the Brazilian Society of Clinical Oncology (SBOC).

A biosimilar is a biologic product that is similar to a reference biopharmaceutical product, the manufacturing process of which hinders the ability to identically replicate the structure of the original product, and therefore, it cannot be described as an absolute equivalent of the original medication. The currently available technology does not allow for an accurate copy of complex molecules, but it does allow the replication of similar molecules with the same activity. As biosimilars are about to be introduced in oncology practice, these must be evaluated through evidence-based medicine. This manuscript is a position paper, where the Brazilian Society of Clinical Oncology (SBOC) aims to describe pertinent issues regarding the approval and use of biosimilars in oncology. As a working group on behalf of SBOC, we discuss aspects related to definition, labeling/nomenclature, extrapolation, interchangeability, switching, automatic substitution, clinical standards on safety and efficacy, and the potential impact on financial burden in healthcare. We take a stand in favor of the introduction of biosimilars, as they offer a viable, safe, and cost-effective alternative to the biopharmaceutical products currently used in cancer. We hope this document can provide valuable information to support therapeutic decisions that maximize the clinical benefit for the thousands of cancer patients in Brazil and can contribute to expedite the introduction of this new drug class in clinical practice. We expect the conveyed information to serve as a basis for further discussion in Latin America, this being the first position paper issued by a Latin American Oncology Society.

On-line arsenic co-precipitation on ethyl vinyl acetate turning-packed mini-column followed by hydride generation-ICP OES determination.

An alternative and new system for on-line preconcentration of arsenic by sorption on a mini-column associated to hydride generation--inductively coupled plasma--optical emission spectrometry determination was studied. It is based on the sorption of arsenic on a column packed with ethyl vinyl acetate (EVA) turnings and the use of La(III) as co-precipitant reagent. This polymeric material was employed here for the first time as filling material for column preconcentration. It could work both as adsorbent and as sieve material. Sample and co-precipitant agent (lanthanum nitrate) were off-line mixed and merged with ammonium buffer solution (pH 10.0), which promoted precipitation and quantitative collection on the small EVA turnings. The arsenic preconcentrated by co-precipitation with lanthanum hydroxide precipitate was subsequently eluted with hydrochloric acid, which was the medium used for hydride generation. Considering a flow rate of 5 ml/min, three enrichment factors were obtained, 28-, 38- and 45-fold at three different sampling times, 60, 120 and 180s; respectively. The detection limits (3s) obtained for each case were 0.013, 0.009 and 0.007 microg/l. Additionally, the calculated precisions expressed as relatively standard deviation (R.S.D.) were 0.9, 1.3 and 1.1%. Satisfactory results were obtained for the determination of arsenic in standard reference material NIST 1643e Trace Elements in Water and drinking water samples.

A randomized trial of chemotherapy followed by pelvic radiation therapy in stage IIIB carcinoma of the cervix.

Because of the poor results in stage III B carcinoma of the cervix with standard treatment using radiotherapy alone, we designed a randomized trial to determine whether administration of chemotherapy before pelvic irradiation would improve survival. Between May 1984 and August 1986, 107 patients with previously untreated squamous cell carcinoma were randomly assigned, after stratification by age (less than 50 v greater than 50 years), extent of parametrial involvement (unilateral v bilateral), and lymphangiographic findings (negative v positive) to pelvic radiotherapy (RT; arm A) or three cycles of chemotherapy (CT; bleomycin, vincristine, mitomycin, and cisplatin [BOMP]), followed by the same radiotherapy regimen (CT + RT; arm B). The groups were balanced by age, performance status, extent of parametrial involvement, bulkiness of cervical disease, nodal involvement, and presence of hydronephrosis. Minimal follow-up is 34 months. A complete local response was observed in 32.5% of the patients in arm A and in 47% of the patients in arm B (P = .19). Overall 5-year survival rates were 39% for the RT arm and 23% for the CT + RT approach (P = .02). Toxicity was severe in arm B and included fatal pulmonary toxicity in four patients. Locoregional and distant failures were similar in both groups. We conclude that, despite a satisfactory response rate, neoadjuvant BOMP chemotherapy adversely affects survival in stage III B cervical cancer and is associated with unacceptable toxicity.

Increased pulmonary toxicity with bleomycin and cisplatin chemotherapy combinations.

Combination chemotherapy that included bleomycin and cisplatin was administered to 45 evaluable patients (30 with cervix carcinoma and 15 with germ cell tumors). Bleomycin was given, following cisplatin infusion, either by intravenous continuous infusion over 72 h (germ cell tumor patients) or intramuscularly every 12 h for 4 days (cervix carcinoma patients). Total bleomycin doses ranged from 156 to 360 U. Nine patients with normal renal function and no previous pulmonary disease prior to chemotherapy developed serious pulmonary toxicity. Six patients died from irreversible respiratory failure. Postmortem lung studies were performed in all six patients and revealed findings compatible with bleomycin-induced lung toxicity. Renal tubular damage was found in four kidneys available for examination. Five (71.5%) of the seven patients whose serum creatinine increased after chemotherapy was initiated developed lung injury, whereas 10.5% of those without change in the serum creatinine level presented this complication (p = 0.001). Renal damage, following cisplatin administration, with subsequent accumulation of bleomycin was the likely cause of the high lung toxicity. Extreme caution is recommended in the administration of combined bleomycin-cisplatin chemotherapy. Whenever possible, bleomycin should precede cisplatin infusion to minimize the risk of lung toxicity.

Long-term results with MACOP-B in the treatment of aggressive non-Hodgkin's lymphomas. The experience in Brazil.

From October 1984 to December 1989, 59 patients with aggressive non-Hodgkin's lymphomas (diffuse mixed, diffuse large cell, and immunoblastic) were treated with MACOP-B. All patients were previously untreated and most of them had advanced disease. Complete response (CR) was observed in 66%. Actuarial overall survival, failure-free survival (FFS), and relapse-free survival at 8 years were 54%, 52%, and 81%, respectively, with a median follow-up of 76 months (range: 28-92 months). The presence of B symptoms influenced significantly the CR rate, while FFS was affected by B symptoms, bone marrow involvement, and number of extranodal sites. Toxicity was high, with mucositis grade 2 or 3 occurring in 70%, leukopenia grades 3 or 4 in 80%, and death in 11.8% of the patients. MACOP-B was active in the treatment of aggressive non-Hodgkin's lymphomas, mainly in patients with few poor-prognosis factors, but other less toxic regimens would be more appropriate for this population. For poor-prognosis patients, new therapeutic modalities are necessary.

Preconcentration and speciation of chromium in drinking water samples by coupling of on-line sorption on activated carbon to ETAAS determination.

An on-line flow injection (FI) preconcentration-electrothermal atomic absorption spectrometry (ETAAS) method is developed for trace determination of chromium in drinking water samples by sorption on a conical minicolumn packed with activated carbon (AC) at pH 5.0. The chromium was removed from the minicolumn with 1.0% (v/v) nitric acid. An enrichment factor (EF) of 35-fold for a sample volume of 10ml was obtained. The detection limit (DL) value for the preconcentration method proposed was 3.0ngl(-1). The precision for 10 replicate determinations at the 0.5mugl(-1) Cr level was 4.0% relative standard deviation (R.S.D.), calculate with the peak heights obtained. The calibration graph using the preconcentration system for chromium was linear with a correlation coefficient of 0.9992 at levels near the detection limits up to at least 50mugl(-1). The method was successfully applied to the determination of Cr(III) and Cr(VI) in drinking water samples.

Cerebellar syndrome caused by isoniazid.

Treatment of tuberculosis in a hemodialysis patient with isoniazid, rifampin, and pyrazinamide resulted in the development of acute cerebellar dysfunction. This resolved rapidly following the discontinuation of isoniazid and pyrazinamide, reinstitution of isoniazid at a lower dose, and addition of pyridoxine. We discuss why we believe this syndrome was caused by isoniazid. Patients with renal failure who undergo antituberculous therapy with isoniazid should receive supplemental pyridoxine to reduce the likelihood of isoniazid-related neurotoxicity.

A randomized trial comparing radiation therapy versus concomitant radiation therapy and chemotherapy in carcinoma of the thoracic esophagus.

From September 1982 to December 1985, 59 previously untreated patients with Stage II squamous cell carcinoma of the thoracic esophagus were randomly assigned to receive radiation therapy (RT) alone versus the concomitant use of RT and chemotherapy (CT) with 5-fluorouracil (5-FU), mitomycin C, and bleomycin (RT + CT). Thirty-one patients were randomized to the RT regimen and 28 to the RT + CT regimen. The complete local response rate was 58% for the RT group and 75% for the RT + CT group (P = 0.77). The median duration of response was 8 months for both groups. The overall 5-year survival rates were 6% and 16% (P = 0.16) for the RT and RT + CT groups, respectively. Acute toxicities were more pronounced in the RT + CT group. This clinical trial did not detect a difference in outcome with combined-technique therapy. This result must be interpreted with caution because of the small number of patients entered in this trial. Confirmation of the value or lack of value for combined therapy will require additional larger clinical trials.