Un-biodegradable and biodegradable plastic sheets modify the soil properties after six months since their applications.

Nowadays, microplastics represent emergent pollutants in terrestrial ecosystems that exert impacts on soil properties, affecting key soil ecological functions. In agroecosystems, plastic mulching is one of the main sources of plastic residues in soils. The present research aimed to evaluate the effects of two types of plastic sheets (un-biodegradable and biodegradable) on soil abiotic (pH, water content, concentrations of organic and total carbon, and total nitrogen) and biotic (respiration, and activities of hydrolase, dehydrogenase, ß-glucosidase and urease) properties, and on phytotoxicity (germination index of Sorghum saccharatum L. and Lepidium sativum L.). Results revealed that soil properties were mostly affected by exposure time to plastics rather than the kind (un-biodegradable and biodegradable) of plastics. After six months since mesocosm setting up, the presence of un-biodegradable plastic sheets significantly decreased soil pH, respiration and dehydrogenase activity and increased total and organic carbon concentrations, and toxicity highlighted by S. saccharatum L. Instead, the presence of biodegradable plastic sheets significantly decreased dehydrogenase activity and increased organic carbon concentrations. An overall temporal improvement of the investigated properties in soils covered by biodegradable plastic sheets occurred.

Ants modulate stridulatory signals depending on the behavioural context.

Insect societies require an effective communication system to coordinate members' activities. Although eusocial species primarily use chemical communication to convey information to conspecifics, there is increasing evidence suggesting that vibroacoustic communication plays a significant role in the behavioural contexts of colony life. In this study, we sought to determine whether stridulation can convey information in ant societies. We tested three main hypotheses using the Mediterranean ant Crematogaster scutellaris: (i) stridulation informs about the emitter'caste; (ii) workers can modulate stridulation based on specific needs, such as communicating the profitability of a food resource, or (iii) behavioural contexts. We recorded the stridulations of individuals from the three castes, restrained on a substrate, and the signals emitted by foragers workers feeding on honey drops of various sizes. Signals emitted by workers and sexuates were quantitatively and qualitatively distinct as was stridulation emitted by workers on different honey drops. Comparing across the experimental setups, we demonstrated that signals emitted in different contexts (restraining vs feeding) differed in emission patterns as well as certain parameters (dominant frequency, amplitude, duration of chirp). Our findings suggest that vibrational signaling represents a flexible communication channel paralleling the well-known chemical communication system.

The morphology and activity of the extrafloral nectaries in Reynoutria × bohemica (Polygonaceae).

Reynoutria × bohemica is an invasive species causing significant damage to native ecosystems in North America and Europe. In this work, we performed an in-depth micromorphological characterisation of the extrafloral nectaries (EFN), during their secretory and post-secretory phases, in combination with field monitoring of nectary activity over time and the qualitative pool of insect visitors. EFN consist of secretory trichomes and vascularised parenchyma. Polysaccharides, lipids and proteins were histochemically detected in all trichome cells; phenolic substances were detected in parenchyma cells. Our data indicate that all nectary regions are involved in nectar production and release, constituting a functional unit. Moreover, the main compound classes of nectar and their transfer change over time: first, granulocrine secretion for sugars prevails, then eccrine secretion of the lipophilic fraction takes place. Active nectaries are mainly located in the apical portion of the stem during the growth phase (April-May), when we detected the highest number of individuals visited by ants; from mid-August onwards, during flowering, the number of active nectaries declined then ceased production (September), with a concomitant decrease in visits by the ants. The spectrum of nectar-foraging ants mainly included representatives of the genera Formica, Lasius and Camponotus. Reynoutria × bohemica produces an attractive secretion able to recruit local ants that may potentially act as 'bodyguards' for protecting young shoots, reducing secretions during the blooming stage. This defence mechanism against herbivores is the same as that displayed by the parental species in its native areas.

miRNA purification with an optimized PDMS microdevice: Toward the direct purification of low abundant circulating biomarkers.

A reliable clinical assay based on circulating microRNAs (miRNAs) as biomarkers is highly required. Microdevices offer an attractive solution as a fast and inexpensive way of concentrating these biomarkers from a low sample volume. A previously developed polydimethylsiloxane (PDMS) microdevice able to purify and detect circulating miRNAs was here optimized. The optimization of the morphological and chemical surface properties by nanopatterning and functionalization is presented. Surfaces were firstly characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), fluorescamine assay and s-SDTB (sulphosuccinimidyl-4-o-(4,4-dimethoxytrityl) butyrate) assay and subsequently tested for their capacity to adsorb a fluorescent miRNA. From our analysis, modification of surface charge with 0.1% APTMS ((3-Aminopropyl)trimethoxysilane) and 0.9% PEG-s (2-[Methoxy-(polyethyleneoxy)propyl]trimethoxysilane) performed at 60°C for 10min was identified as the best purification condition. Our optimized microdevice integrated with real-time PCR detection, was demonstrated to selectively purify both synthetic and natural circulating miRNAs with a sensitivity of 0.01pM.

Hybrid method inference for the construction of cooperative regulatory network in human.

Reconstruction of large scale gene regulatory networks (GRNs in the following) is an important step for understanding the complex regulatory mechanisms within the cell. Many modeling approaches have been introduced to find the causal relationship between genes using expression data. However, they have been suffering from high dimensionality-large number of genes but a small number of samples, overfitting, heavy computation time and low interpretability. We have previously proposed an original Data Mining algorithm Licorn, that infers cooperative regulation network from expression datasets. In this work, we present an extension of Licorn to a hybrid inference method h-Licorn that uses search in both discrete and real valued spaces. Licorn's algorithm, using the discrete space to find cooperative regulation relationships fitting the target gene expression, has been shown to be powerful in identifying cooperative regulation relationships that are out of the scope of most GRN inference methods. Still, as many of related GRN inference techniques, Licorn suffers from a large number of false positives. We propose here an extension of Licorn with a numerical selection step, expressed as a linear regression problem, that effectively complements the discrete search of Licorn. We evaluate a bootstrapped version of h-Licorn on the in silico Dream5 dataset and show that h-Licorn has significantly higher performance than Licorn, and is competitive or outperforms state of the art GRN inference algorithms, especially when operating on small data sets. We also applied h-Licorn on a real dataset of human bladder cancer and show that it performs better than other methods in finding candidate regulatory interactions. In particular, solely based on gene expression data, h-Licorn is able to identify experimentally validated regulator cooperative relationships involved in cancer.

Innovative microRNA purification based on surface properties modulation.

The increasing interest in circulating microRNAs (miRNAs) as potential non-invasive cancer biomarkers has prompted the rapid development of several extraction techniques. However, current methods lack standardization and are costly and labor intensive. In light of this, we developed a microRNA solid-phase extraction strategy based on charge and roughness modulation on substrate surfaces. PECVD treated silicon oxide (PECVD-SO) and thermally grown silicon oxide (TG-SO) surfaces were functionalized with positively charged 3-aminopropyltriethoxysilanes (APTES) and neutral poly(ethylene glycol) silanes (PEG-s) mixed in different proportions to modulate the density of net positive charges and the roughness of the substrate. Characterization of the surfaces was performed by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and s-SDTB (sulfosuccinimidyl-4-o-(4,4-dimethoxytrityl) butyrate) assay in order to investigate the surface morphology and chemical composition, respectively. Adsorption and elution efficiency were assessed by fluorescence microscopy by means of synthetic fluorescently labeled microRNAs. We identified PECVD-SO functionalized with 0.1% APTES and 0.9% 21-24 units long PEG-s as a promising surface able to selectively bind microRNAs and release them in the presence of a basic buffer (pH=9) compatible with downstream analyses. MicroRNA integrity was assessed by reverse transcription and real-time PCR and confirmed by electrophoresis (Agilent 2100 Bioanalyzer), while binding competition from circulating DNA and proteins was excluded by fluorescence analyses and real-time PCR. On the contrary, total RNA slightly decreased miRNA adsorption. In conclusion, we showed an innovative and easy solid-state purification method for circulating miRNAs based on charge interaction, which could pave the path to future diagnostic and prognostic assays feasible as a routine test.

Validation of the selection process of PhilHealth sponsored members in 4 barangays in a municipality in Batangas using the participatory action research

Objective. The present study aims to correlate the LGU list of PhilHealth Sponsored Members in a municipality of Batangas with the list of poor residents as identified by the Participatory Action Research (PAR) methodology. Method. Interview of key informants documented the processes utilized by the LGU in determining PhilHealth beneficiaries for the Sponsored Program and the Participatory Action Research (PAR) survey in the classification of households into poor, middle and rich in four barangays of the municipality. The list of LGU Sponsored members was then cross matched with the PAR household classification. Results. The comparison of the LGU list of Sponsored members and the household classification by the PAR survey showed a wide discrepancy: (1) 464 "Not Found" Sponsored households or 70% of the LGU's Sponsored list; (2) inclusion of the non-poor: 140 middle class families as classified by the PAR survey or 21.1% of the LGU's Sponsored list; and (3) exclusion of 413 or 87.5% of true poor families identified by the PAR Survey. Only 59 families or 8.9% of the LGU Sponsored list were classified as poor families by PAR. Conclusion. PAR offers communities, LGUs and the National Health Insurance Program a tool to validate the coverage of the Sponsored program. LGUs and the PhilHealth should consider such tool or similar tools to validate their identification, selection and enrollment of the poor, which is extremely vital in achieving universal coverage. Given the right tool, communities are in the best position to identify the poor for the Sponsored program. By way of collaboration with the underprivileged themselves, the academe has a role in assisting communities in acquiring collective awareness of their own situation and developing capacity for improving their lives. The academe also has a role in assisting LGUs in improving their health systems and national health programs in validating and improving their implementation. Further studies should be done to investigate the following: the identity of the "not found" SP members; the utilization of PhilHealth benefits by the poor; and the prospect of utilizing the PAR method by other non-academic institutions in monitoring the progress of community programs.

Validation of the selection process of PhilHealth sponsored members in 4 barangays in a municipality in Batangas using the participatory action research

OBJECTIVE: The present study aims to correlate the LGU list of PhilHealth Sponsored Members in a municipality of Batangas with the list of poor residents as identified by the Participatory Action Research (PAR) methodology. METHOD: Interview of key informants documented the processes utilized by the LGU in determining PhilHealth beneficiaries for the Sponsored Program and the Participatory Action Research (PAR) survey in the classification of households into poor, middle and rich in four barangays of the municipality. The list of LGU Sponsored members was then cross matched with the PAR household classification. RESULTS:The comparison of the LGU list of Sponsored members and the household classification by the PAR survey showed a wide discrepancy: (1) 464 "Not Found" Sponsored households or 70% of the LGU's Sponsored list; (2) inclusion of the non-poor: 140 middle class families as classified by the PAR survey or 21.1% of the LGU's Sponsored list; and (3) exclusion of 413 or 87.5% of true poor families identified by the PAR Survey. Only 59 families or 8.9% of the LGU Sponsored list were classified as poor families by PAR. CONCLUSION:PAR offers communities, LGUs and the National Health Insurance Program a tool to validate the coverage of the Sponsored program. LGUs and the PhilHealth should consider such tool or similar tools to validate their identification, selection and enrollment of the poor, which is extremely vital in achieving universal coverage. Given the right tool, communities are in the best position to identify the poor for the Sponsored program. By way of collaboration with the underprivileged themselves, the academe has a role in assisting communities in acquiring collective awareness of their own situation and developing capacity for improving their lives. The academe also has a role in assisting LGUs in improving their health systems and national health programs in validating and improving their implementation. Further studies should be done to investigate the following: the identity of the "not found" SP members; the utilization of PhilHealth benefits by the poor; and the prospect of utilizing the PAR method by other non-academic institutions in monitoring the progress of community programs.

Upfront high-dose sequential therapy (HDS) versus VACOP-B with or without HDS in aggressive non-Hodgkin's lymphoma: long-term results by the NHLCSG.

BACKGROUND: There is not univocal concordance for using high-dose sequential therapy (HDS) as first-line treatment for aggressive non-Hodgkin's lymphoma (NHL). We designed this study to evaluate the usefulness of HDS followed by high-dose therapy (HDT) with autologous stem cell transplantation as front-line treatment in different subsets of aggressive NHL. PATIENTS AND METHODS: Among 223 patients aged 15-60 years with aggressive, advanced stage NHL, 106 patients were randomized to VACOP-B (etoposide, doxorubicin, cyclophosphamide, vincristine, prednisone, bleomycin) for 12 weeks (plus HDS/HDT in case of persistent disease) (arm A), and 117 patients to VACOP-B for 8 weeks plus upfront HDS/HDT (arm B). RESULTS: According to the intention-to-treat analysis, the complete response rate was 75% for arm A and 72.6% for arm B. With a median follow-up of 62 months there was no difference in 7-year probability of survival (60% and 57.8%; P = 0.5), disease-free survival (DFS) (62% and 71%; P = 0.2) and progression-free survival (PFS) (44.9% and 40.9%; P = 0.7) between the two arms. Subgroup analyses confirmed that the best results in terms of survival, DFS and PFS were achieved by patients with large B-cell NHL without bone marrow (BM) involvement, independently of the treatment arm. Results were poorer in other categories of patients and poorest in patients with BM involvement. CONCLUSIONS: Aggressive NHL patients do not benefit from upfront HDS/HDT.

A third generation regimen VACOP-B with or without adjuvant radiotherapy for aggressive localized non-Hodgkin's lymphoma: report from the Italian Non-Hodgkin's Lymphoma Co-operative Study Group

The objective of this multicenter prospective study was to determine the clinical efficacy and toxicity of a polychemotherapeutic third generation regimen, VACOP-B, with or without radiotherapy as front-line therapy in aggressive localized non-Hodgkin's lymphoma. Ninety-three adult patients (47 males and 46 females, median age 45 years) with aggressive localized non-Hodgkin's lymphoma, 43 in stage I and 50 in stage II (non-bulky), were included in the study. Stage I patients received VACOP-B for 6 weeks plus involved field radiotherapy and stage II patients received 12 weeks VACOP-B plus involved field radiotherapy on residual masses. Eighty-six (92.5 percent) achieved complete remission and 4 (4.3 percent) partial remission. Three patients (3.2 percent) were primarily resistant. Ten-year probability of survival, progression-free survival and disease-free survival were 87.3, 79.9 and 83.9 percent, respectively. Eighty-four patients are surviving at a median observation time of 57 months (range: 6-126). Statistical analysis showed no difference between stages I and II in terms of response, ten-year probability of survival, progression-free survival or disease-free survival. Side effects and toxicity were negligible and were similar in the two patient groups. The results of this prospective study suggest that 6 weeks of VACOP-B treatment plus radiotherapy may be the therapy of choice in stage I aggressive non-Hodgkin's lymphoma. Twelve weeks of VACOP-B treatment with or without radiotherapy was shown to be effective and feasible for stage II. These observations need to be confirmed by a phase III study comparing first and third generation protocols in stage I-II aggressive non-Hodgkin's lymphoma.

A third generation regimen VACOP-B with or without adjuvant radiotherapy for aggressive localized non-Hodgkin's lymphoma: report from the Italian Non-Hodgkin's Lymphoma Co-operative Study Group.

The objective of this multicenter prospective study was to determine the clinical efficacy and toxicity of a polychemotherapeutic third generation regimen, VACOP-B, with or without radiotherapy as front-line therapy in aggressive localized non-Hodgkin's lymphoma. Ninety-three adult patients (47 males and 46 females, median age 45 years) with aggressive localized non-Hodgkin's lymphoma, 43 in stage I and 50 in stage II (non-bulky), were included in the study. Stage I patients received VACOP-B for 6 weeks plus involved field radiotherapy and stage II patients received 12 weeks VACOP-B plus involved field radiotherapy on residual masses. Eighty-six (92.5%) achieved complete remission and 4 (4.3%) partial remission. Three patients (3.2%) were primarily resistant. Ten-year probability of survival, progression-free survival and disease-free survival were 87.3, 79.9 and 83.9%, respectively. Eighty-four patients are surviving at a median observation time of 57 months (range: 6-126). Statistical analysis showed no difference between stages I and II in terms of response, ten-year probability of survival, progression-free survival or disease-free survival. Side effects and toxicity were negligible and were similar in the two patient groups. The results of this prospective study suggest that 6 weeks of VACOP-B treatment plus radiotherapy may be the therapy of choice in stage I aggressive non-Hodgkin's lymphoma. Twelve weeks of VACOP-B treatment with or without radiotherapy was shown to be effective and feasible for stage II. These observations need to be confirmed by a phase III study comparing first and third generation protocols in stage I-II aggressive non-Hodgkin's lymphoma.

An EBMT registry matched study of allogeneic stem cell transplants for lymphoma: allogeneic transplantation is associated with a lower relapse rate but a higher procedure-related mortality rate than autologous transplantation.

The role of allogeneic bone marrow transplantation in lymphoma remains uncertain. We have analyzed 1185 allogeneic transplants for lymphoma reported to the EBMT registry between 1982 and 1998 and compared the results with those of 14687 autologous procedures performed over the same period. Patients receiving allogeneic transplants were subdivided according to histology: low-grade non-Hodgkin's lymphoma (NHL) 231 patients; intermediate-grade NHL 147 patients; high-grade NHL 255 patients; lymphoblastic NHL 314 patients; Burkitt's lymphoma 71 patients; and Hodgkin's disease 167 patients. These patients received allogeneic transplants as their first transplant procedure. Actuarial overall survival (OS) at 4 years from transplantation was: low-grade NHL 51.1%; intermediate-grade NHL 38.3%; high-grade NHL 41.2%; lymphoblastic lymphoma 42.0% years; Burkitt's lymphoma 37.1%; and Hodgkin's disease 24.7% years. These outcomes are relatively poor because of the high procedure-related mortality associated with these procedures, particularly in patients with Hodgkin's disease (51.7% actuarial procedure-related mortality at 4 years). Multivariate analysis showed that for all lymphomas apart from Hodgkin's disease, status at transplantation significantly affected outcome. A matched analysis was performed: for all categories of lymphoma, OS was better for autologous than for allogeneic transplantation. Relapse rate was better in the allogeneic group for low-, intermediate- and high-grade, and lymphoblastic NHL. It was equivalent for Burkitt's lymphoma and worse in the allogeneic group for Hodgkin's disease. Allogeneic transplantation appears to be superior to autologous procedures in terms of producing a lower relapse rate. The toxicity of allogeneic procedures must however be reduced before this translates into an improvement in OS.

Control of acute pain after major abdominal surgery in 585 patients given tramadol and ketorolac by intravenous infusion.

The aim of this study was to assess the efficacy and safety of postoperative pain relief using tramadol and ketorolac in continuous intravenous infusion. The 585 patients included in the study underwent major surgery according to a protocol involving the parenteral administration of 100 mg tramadol approximately 40 min before the end of surgery. This was followed by the continuous intravenous infusion of 600 mg tramadol and 180 mg ketorolac diluted with physiological solution to a total volume of 96 ml. Delivery was carried out using an elastomeric pump or a syringe pump and administered over a 48-hour period at a constant rate of 2 ml/h. Any further doses consisted of 100 mg tramadol up to a maximum of 300 mg over a 24-h period. Pain was assessed on a verbal numeric scale (VNS). For each patient the intensity of pain was assessed both at rest and on movement (coughing, deep breathing, movement of lower limbs). At the scheduled times (T0-T72, every 6 h), the following parameters were evaluated: hemodynamic stability; respiratory function; the appearance of any side effects; the level of sedation; and the need for any further doses of analgesic. The analysis of the data obtained showed the good quality of postoperative pain relief achieved: pain intensity at rest was, on average, always below VNS level 3, while during movement it always had an average VNS level of 3-4. The only side effects found with any frequency were nausea (22.6%) and vomiting (8.5%); hemodynamic and respiratory parameters remained stable. The method adopted was of limited cost and was well accepted by both patients and staff. On the basis of the data obtained, it is possible to affirm that the post-operative pain protocol proposed is effective, safe, without significant side effects, and of limited cost. Therefore, it is the first choice protocol for our operating unit after major abdominal surgery.

Laparoscopic splenectomy for hematological diseases.

BACKGROUND: We reviewed retrospectively the records of all patients who underwent laparoscopic splenectomy (LS) at our institution for a wide range of hematological disorders. We compared our experience to those reported in the literature and analyzed various aspects of the treatment that are still under discussion and in need of confirmation, such as the treatment of malignant blood diseases, the indication in case of splenomegaly, and the adequacy of the detection of accessory spleens. METHODS: Between June 1997 and June 2001, we performed 43 LS. The patients were classified into three groups according to clinical diagnosis: idiopathic thrombocytopenic purpura (ITP) (n = 23), hemolytic anemia (HA) (n = 5), and hematological malignancy (HM) (n = 15). Statistical analyses were done to compare the three groups. RESULTS: LS was completed in 41 patients, with a conversion rate of 5%. Splenomegaly was present in 37% of all patients (73% of HM). Mean operative time was 128 min. The incidence of accessory spleens was 20%. A concomitant laparoscopic procedure was done in three cases (cholecystectomy). Postoperative complications occurred in eight patients (18%). Duration of surgery, length of hospital stay, transfusions rate, and some demographics features, such as age and spleen weight and length, were significantly different in each group. No deaths were attributed to the procedure. CONCLUSIONS: The statistical analysis of our series shows that, the laparoscopic approach reliable even in the management of malignant and nonmalignant blood diseases.

ABVD versus stanford V versus MEC in unfavourable Hodgkin's lymphoma: results of a randomised trial.

BACKGROUND: Between January 1996 and April 2000, 355 patients with advanced Hodgkin's disease (HD) (stage II bulky disease, III and IV) were enrolled in a prospective, multicentre, randomised trial aimed at comparing the efficacy of two new promising regimens: Stanford V and MEC hybrid. ABVD was chosen as the control arm. Radiotherapy was planned at the end of induction therapy on residual masses or on sites of previous bulky lesions. One hundred and seventeen, 123 and 115 patients were treated with Stanford V, MEC and ABVD, respectively. The records of 275 enrolled patients (89 Stanford V, 88 MEC, 98 ABVD) have been reviewed and are the subject of this report. RESULTS: After induction therapy a complete response (CR) was observed in 93, 89 and 74% of patients treated with MEC, ABVD and Stanford V, respectively, with a statistically significant difference (P = 0.013) between the arms. After a median follow-up of 24 months, 16 relapses have been recorded among 196 patients who achieved a CR. Relapse rates are 16, 6 and 4% for Stanford V, ABVD and MEC, respectively (P = 0.042). The 3-year survival was 93%, without any significant difference among the arms. However, a significant difference emerged in terms of failure free survival (FFS). Patients treated with Stanford V did the worst compared with those treated with ABVD or MEC (P = 0.001). Toxicity was comparable in the three treatment arms. CONCLUSION: For this randomised study, both ABVD and MEC gave superior results to Stanford V in terms of response and FFS; MEC seems to be the best regimen in terms of relapse-free survival, even if a significant difference has not yet been achieved. Notwithstanding the short follow-up, these results seem to be very impressive in defining the best standard treatment for HD for this subset of patients.

Autologous stem cell transplantation for aggressive non-Hodgkin's lymphomas

O transplante autólogo de célula progenitora ou medula óssea (ATMO) tem demonstrado capacidade de superar resistência tumoral através da elevação da intensidade de dose de drogas disponíveis e radioterapia. ATMO foi inicialmente utilizado em LNH após recidiva em primeira linha ou refratários. ATMO tem demonstrado maior utilidade em condições clínicas mais favoráveis como na remissão parcial (RP), primeira remissão completa (RC) e como primeira linha após quimioterapia. Quimioterapia de alta dose e ATMO se tornaram a terapêutica standard para pacientes elegíveis com LNH agressivo, recorrente e quimiosensível. Pacientes primariamente refratários e com recidiva resistente não são boas indicações e devem ser considerados como grupo elegível para estudos de fase II. Talvez, haja um papel do ATMO em pacientes parcialmente responsivos. Entretanto, novos e grandes estudos randomizados são necessários para esclarecer esta questão. Um desafio para o manuseio dos linfomas é a definição da terapia de alta dose seguida do ATMO como terapêutica inicial para os LNH agressivos, identificando pacientes que não possam ser curados com terapêutica convencional. Uma série de estudos retrospectivos ou controlados parece indicar os chamados pacientes de "alto-risco", definido pela IPI como potencial alvo destas terapêuticas intensificadas. Entretanto, de acordo com dados publicados, o problema permanece aberto para debates. Estudos grandes e randomizados são necessários e bem vindos e devem ser considerados prioridade neste campo da ciência médica.

High-dose chemotherapy shows a dose-dependent toxicity to bone marrow osteoprogenitors: a mechanism for post-bone marrow transplantation osteopenia.

BACKGROUND: Osteoporosis is a sequela of hemopoietic cell transplantation with a complex multifactorial pathogenesis in which the relative role of chemotherapy and irradiation is not completely understood. Therefore, the authors investigated the toxicity of chemotherapy-only conditioning regimens on bone homeostasis and bone marrow osteoprogenitors, its dose dependency, and the mechanism of chemotherapy-induced osteopenia. METHODS: Fifty-one patients with high-grade non-Hodgkin lymphoma or breast carcinoma who had been treated previously with high-dose + peripheral blood progenitor cell or conventional chemotherapy or who had not received any treatment (prechemotherapy) were enrolled. The authors measured the bone marrow colony-forming unit fibroblast (CFU-f) and long-term culture-initiating cell frequency, forearm bone mineral density, serum osteotropic hormones and metabolic markers of bone formation (plasma osteocalcin), and resorption (urinary collagen I C-crosslinks). RESULTS: Both high-dose chemotherapy regimens caused a 50% reduction in CFU-f frequency, independently of gonadal function status, whereas conventional chemotherapy and prechemotherapy groups were unaffected. Bone mineral density was measured in 26 non-Hodgkin lymphoma patients and again only high-dose chemotherapy caused a 10% loss in cortical bone and 20% in trabecular bone. No endocrine abnormality was found except for the secondary amenorrhea uniformly induced in the high-dose chemotherapy group. In these patients, plasma osteocalcin unexpectedly failed to increase in response to the menopausal increase in bone resorption rate, showing a selective impairment of the osteoblast compartment to cope with increased functional demand. CONCLUSIONS: Chemotherapy without irradiation shows a dose-dependent toxicity to bone marrow stromal osteoprogenitors and can cause osteopenia by direct damage of the osteoblastic compartment, as a mechanism distinct from and summable to hypogonadism.

The human pharmacology of monocyte cyclooxygenase 2 inhibition by cortisol and synthetic glucocorticoids.

BACKGROUND: We studied the concentration dependence of the inhibitory effects of cortisol, 6-methylprednisolone, and dexamethasone on cyclooxygenase-2 (COX-2) expression and activity in human monocytes in response to lipopolysaccharide (LPS) in vitro. Moreover, we characterized the time and dose dependence of the inhibitory effects of 6-methylprednisolone, administered to healthy subjects, on LPS-inducible prostaglandin E2 (PGE2) biosynthesis in whole blood ex vivo. METHODS: Heparinized whole-blood samples obtained from healthy subjects and patients with rheumatoid arthritis were incubated with LPS (10 microg/ml) for 24 hours at 37 degrees C, and PGE2 was measured in plasma as an index of monocyte COX-2 activity. Comparative experiments were performed in LPS-stimulated isolated monocytes. The levels of COX-2-like immunoreactivity in monocyte lysates were measured by a specific Western blot technique. PGE2 was evaluated by radioimmunoassay. RESULTS: Nanomolar concentrations of cortisol, 6-methylprednisolone, and dexamethasone suppressed LPS-induced PGE2 biosynthesis both in whole blood and in isolated monocytes in vitro with relative potencies similar to those reported for their anti-inflammatory effects in vivo. The administration of single oral doses (4, 8, or 16 mg) of 6-methylprednisolone caused a dose- and time-dependent inhibition of whole-blood COX-2 activity. Whole-blood samples obtained from patients with rheumatoid arthritis treated with comparable maintenance doses of glucocorticoids produced significantly lower levels of LPS-inducible PGE2 than were found in untreated patients. CONCLUSIONS: Therapeutic plasma levels of synthetic glucocorticoids down-regulate inducible prostanoid biosynthesis in circulating monocytes. This effect may represent a readily measurable surrogate marker of their clinical efficacy for dose-finding studies.

Mitochondrial perturbations and oxidant stress in lymphocytes from patients undergoing surgery and general anesthesia.

BACKGROUND: Previous studies have shown that a profound suppression of immune function transiently occurs in patients who undergo surgery under general anesthesia. The decline in the absolute counts of peripheral blood lymphocytes constitutes a major factor accounting for this immune defect, and recent evidence indicates that apoptosis plays a crucial role in determining postsurgical lymphocytopenia. HYPOTHESIS: An altered oxidation-reduction status of mitochondria may contribute through apoptosis to the loss of lymphocytes following surgical trauma and general anesthesia. DESIGN: We studied 16 patients with American Society of Anesthesiologists' physical status I or II who underwent elective surgery under general anesthesia. The data were collected prospectively. SETTING: University hospital. MAIN OUTCOME MEASURES: Samples of peripheral blood were drawn on the day before surgery and at 24 and 96 hours after the operation. Following lymphocyte isolation, the mitochondrial transmembrane potential was assessed by flow cytometry using 3,3'-dihexylocarbo-cyanine iodide, and stains with hydroethidine and 2'-7'-dichlorofluorescein diacetate were used to determine the generation of reactive oxygen species. The labeling of lymphocytes with monobromobimane was used to assess the presence of reduced glutathione. RESULTS: At 24 hours after surgery, we detected a significantly elevated frequency of peripheral blood lymphocytes (P =.002), which incorporated low levels of 3,3'-dihexylocarbo-cyanine iodide, compared with the preoperative period. At this same time point, the frequency of lymphocytes with the hydroethidine- and 2'-7'-dichlorofluorescein diacetate-positive phenotype was elevated compared with baseline levels. Conversely, at 24 hours after surgery, the frequency of cells that stained positive for glutathione was strongly decreased compared with preoperative values. Overall measurements returned to the baseline levels at 96 hours after surgery. CONCLUSION: The strict association we observed between the overproduction of reactive oxygen species and the disruption of the mitochondrial transmembrane potential supports the view that alterations in mitochondrial energy metabolism, paralleled by the presence of a pro-oxidant oxidation-reduction status, could be involved in the accelerated apoptotic loss of lymphocytes following surgical trauma and general anesthesia.

Metabolic responses of the limpet Patella caerulea (L.) to anoxia and dehydration.

This study examined the metabolic responses of the limpet Patella caerulea (L.) to anoxia and dehydration, attempting to tease apart the effect of these two stressful conditions, which are often not clearly distinguished in experiments. Specimens were exposed to: (a) oxygen-free sea water; (b) oxygen-saturated water (controls); (c) low-humidity air (55% RH); and (d) high-humidity air (100% RH). For each of the treatments, we took samples of five specimens after 6 and 18 h of exposure to the experimental conditions and determined the concentrations in the foot muscle of succinate, acetate, propionate, aspartate and alanine. Exposure to anoxia caused an increase in the levels of succinate (6 and 18 h) and acetate and propionate (18 h) with respect to control specimens. Anoxia also induced a decrease of aspartate and an increase of alanine after both 6 and 18 h. Exposure to both moist and dry air generally had negligible effects on the organic acid levels. Aspartate content increased after 18 h of exposure to moist air. Alanine levels also increased with respect to control values after exposure to air, with dry air having the more pronounced effect. In conclusion, the results of this study suggest that one should be cautious when inferring anaerobic conditions from the simple exposure of intertidal species to air, without strict control of the experimental conditions and actual respiration rates.