WSXM: a software for scanning probe microscopy and a tool for nanotechnology

In this work we briefly describe the most relevant features of WSXM, a freeware scanning probe microscopy software based on MS-Windows. The article is structured in three different sections: The introduction is a perspective on the importance of software on scanning probe microscopy. The second section is devoted to describe the general structure of the application; in this section the capabilities of WSXM to read third party files are stressed. Finally, a detailed discussion of some relevant procedures of the software is carried out.

Effects of combined cholinergic-purinergic block upon cat carotid body chemoreceptors in vitro

Since acetylcholine (ACh) and ATP have been proposed as excitatory co-transmitters at synapses between glomus cells and sensory nerve endings of the carotid body (CB), we tested such hypothesis by studying the effects of combined cholinergic-purinergic block on the chemosensory activity recorded from cat's carotid bodies perfused and/or superfused in vitro. The preparations were bathed with Tyrode's solution, either normoxic (PO2=98.5+/-13.5 Torr) or hypoxic (PO2=31.8+/-5.2 Torr), and the frequency of chemosensory impulses (fchi) was recorded from the carotid (sinus) nerve. Dose-response curves for fchi increases evoked by intra-stream boluses of acetylcholine, nicotine and ATP were studied. A combination of mecamylamine 2 microM and suramin 50 microM, applied through the perfusate or superfusate, suppressed nicotine- and ATP-induced increases in fchi, but the basal chemosensory activity in normoxia and the chemosensory excitation elicited by hypoxic superfusion were preserved, although variably reduced in most preparations. Thus, in spite of the excitatory effects provoked by applying ACh and ATP to the perfused/superfused CB in vitro, a co-release of these substances cannot account entirely for the chemosensory excitation induced by hypoxic stimulation of the CB.

Carotid body chemosensory activity and ventilatory chemoreflexes in cats persist after combined cholinergic-purinergic block

Acetylcholine (ACh) and ATP have been proposed as excitatory co-transmitters operating at synapses between glomus cells and sensory nerve endings of the carotid body (CB). To test such hypothesis, we performed experiments on cats under pentobarbitone anesthesia and breathing spontaneously. Cholinergic and purinergic agonists and antagonists were given into one common carotid artery. Chemoreflex ventilatory changes initiated from the ipsilateral CB or chemosensory activity from the ipsilateral carotid nerve were recorded. Agonists ACh, nicotine, epibatidine, ATP, betagamma-methylene-ATP and gammaS-ATP induced transient chemoreflex enhancements of ventilation or increased chemosensory activity. When given in combination, mecamylamine and suramin suppressed both nicotine- and ATP-induced ventilatory chemoreflexes or chemosensory responses. However, neither chemoreflex hyperventilation induced by brief hypoxic exposures or steady-state hypoxic levels, nor chemosensory excitation elicited by these maneuvers were eliminated. Asphyxia-induced chemosensory excitation was not reduced by combined blockade of ACh and ATP receptors. Furthermore, ventilatory or chemosensory depression evoked by 100% O2 tests was unmodified, thus evidencing that basal chemosensory drive in normoxia was not suppressed by combined cholinergic-purinergic blockade. Therefore, although ACh and ATP may participate in chemoexcitation of the CB, their involvement fails to explain the origin of chemosensory discharges from synaptic transmission between glomus cells and chemosensory nerve endings of the CB.

Elderly patients with advanced non-small cell lung cancer (nsclc). Results of chemotherapy and comparison with younger patients

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Background: Lung cancer is increasingly diagnosed in elderly patients and is the first cause of cancer death. Treatment of this subset represents a challenge to medical oncologists. Methods: We retrospectively reviewed clinical characteristics, co-morbidity (Charlson Index), toxicity and results of all patients ≥ 65 years (y) old, diagnosed of advanced NSCLC. We compared these results with younger patients’. Results: From January-95 to June-02, we treated 477 patients (pt), 176 ≥ 65 years, 301 < 65 y. Treatment: 177 pt, MIC (mitomycine + ifosfamide + cisplatin), 60 ≥ 65 y and 117 < 65 y; 156, CG (Cisplatin + Gemcitabine), 52 > 65 y and 104 < 65 y; 144, CP (Cisplatin + Paclitaxel), 64 ≥ 65 y and 120 < 65 y. Characteristics: median age 60 (31–78); 428 male, 49 female; ECOG 0/1/2/3: 83/312/71/5, Stage IIIA, IIIB and IV: 72/199/206, Histology: squamous carcinoma 215, adenocarcinoma 190, large cell 19, bronchioloalveolar 7, undifferentiated 45 pt. No significant differences between the two groups. Overall response rate: 39% (CR, 32.9%, PR, 6.1%), Stable disease 26.4% and Progressive disease, 26.4%. Patients ≥ 65 y: CR 5.7%, PR 45.5%, SD 23.3% and PD 18.2%. Patients < 65 y: CR 6.3% PR 25.6%, SD 28.2% and PD 31.2%. Predictive factors for response: ECOG and stage. Response rate was superior in patients ≥ 65 y and in patients ≥ 70 y. Overall survival: 38.29 weeks (w): < 65 y, 38.57 w; 65–70 y, 37.71 w and ≥ 70 y, 37 w. Multivariate analysis: ECOG, stage and sex were prognostic factors; age, histology, Charlson index and schedule treatment were not significant. Grade 3/4 episodes of toxicity: ≥ 65 y, 184/17, and < 65 y, 232/8. Treatment delays: ≥ 65 y, 115 and < 65 y, 100. Hospitalization due to toxicity: >≥ 65 y, 34 and < 65 y, 23. Treatment was stopped in 13 pt >≥ 65 y and in 7 pt < 65 y. Conclusions: Age is not a predictive factor for response to chemotherapy, neither a prognostic factor for survival. Charlson index does not seem to be useful for these patients. Although toxicity is superior, cisplatin-based schedules are safe and active.

No significant financial relationships to disclose.

Concurrent chemoradiotherapy (crt) with weekly docetaxel (d) for advanced head and neck cancer

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Background: Concomitant CRT has become a standard treatment for advanced head and neck cancer. The aim of this study was to evaluate the efficacy and toxicity of concurrent CRT with D in patients (pts) with advanced squamous cell carcinoma of head and neck (SCCHN). Methods: Patients with untreated and unresectable stage III or IV (M0) squamous cell carcinoma of head and neck were included. Treatment consisted of D 20 mg/m2 weekly with concomitant radiotherapy 70 Gy (2 Gy per day, 7 weeks). Results: From September 03 to October 05, sixty-four pts with advanced SCCHN, were recruited. Gender: 61 male, 3 female. Mean age: 56.5 years old (range 42–77). ECOG PS 0/1/2: 0/57/7. Primary sites of disease: oral cavity 8, oropharynx 26, hypopharynx 15 and larynx 15. Stage III 16 pts and stage IV 48 pts. Compliance: 393 administrations of D were given, median 6, mean 6 (range 1–8). Fifty-five pts (86%) completed the radiotherapy dose planned (mean dose of RT was 66 Gy). One refused more treatment with D after first administration. Nineteen pts required supportive percutaneous gastrostomy or nasogastric tubes previously or during therapy. Grade 2/3/4 toxicity per patient: anemia 4/2/0, mucositis 21/24/0, dermatitis 21/20/0. Neither thrombopenia nor neutropenia were observed. Four pts died of aspiration pneumonia during treatment, one of gastric perforation and two of unknown causes. Fifty-six pts were evaluable for response: CR 28 (44%), PR 23 (36%), SD 2 (3%), PD 3 (5%), with an overall response rate of 80%. Median overall survival was 74.86 weeks (95% CI: 40.40–109.32) and median progression free survival was 48 weeks (95% CI: 18.80–77.20). With a median follow up of 40 weeks 34 pts (53%) were alive and 21 of them (33%) remained free of disease. Conclusions: Concurrent weekly D with conventional radiotherapy showed a high response rate. Toxicity was manageable and allowed maintaining radiotherapy administration. Taking into account poor prognostic factors of our series, survival results seem promising.

No significant financial relationships to disclose.

Basiliximab in lung transplantation: preliminary experience

BACKGROUND

Basiliximab is a chimeric anti-interleukin-2 monoclonal antibody that has shown safety and efficacy in the prophylaxis of acute organ rejection in renal, liver, heart, and kidney-pancreas transplantation (Tx). The aim of this study was to present our initial experience with the use of Basiliximab in lung Tx.

METHODS

Basiliximab (2 doses of 20 mg on day 0 and day 4) was administered to 16 patients treated with cyclosporine, azathioprine, and steroids between September 13, 2001 and August 26, 2003, including 12 men and 4 women patients with a mean age of 56.5 years (range, 19-69). The indication for use in transplantations were: reduced renal function (n = 14), post-Tx acute renal failure (n = 1) and steroid-resistant acute rejection (n = 1). Eight double-lung and eight single-lung Tx were performed for emphysema (n = 6), idiopathic pulmonary fibrosis (n = 7), silicosis (n = 2), and cystic fibrosis retransplantation (n = 1).

RESULTS

The incidence of acute rejection was 16.6% (2 patients). Infections included cytomegalovirus (CMV) 33.3% (n = 4), bacterial 16.6% (n = 2), and fungal 8.3% (n = 1). Two patients died in the postoperative period and another at 3 months. There was no reaction to the medicine, and no malignancies or Bronchiolitis Obliterans Syndrome (BOS) during a follow-up period of more than 1 year in 10 patients.

CONCLUSION

Basiliximab appeared to reduce the incidence of acute organ rejection and showed a good safety profile in terms of infections and adverse events.

[Transbronchial needle aspiration in bronchogenic carcinoma with visible lesions: diagnostic yield and cost]

BACKGROUND

Transbronchial needle aspiration (TBNA) is a bronchoscopic technique whose usefulness in diagnosing endobronchial lesions has not yet been clearly established.

OBJECTIVE

We aimed to determine whether the diagnostic yield of fiberoptic bronchoscopy could be increased, without a negative impact on diagnostic costs, if TBNA were used in combination with conventional diagnostic techniques (bronchial washings and bronchial brushings and forceps biopsy).

PATIENTS AND METHODS

The cases of 130 patients diagnosed with bronchogenic carcinoma with endoscopically visible lesions were analyzed retrospectively. All had undergone conventional diagnostic procedures; TBNA was also performed if the bronchoscopist considered it was indicated. The final cost was calculated in euros for each diagnosis as the sum of the cost of the procedures needed to reach the diagnosis, including both endoscopic procedures and others (transthoracic needle aspiration, lymph node biopsy). Diagnostic yield and costs in cases diagnosed using only conventional techniques were compared to the yield and costs in cases in which both conventional techniques and TBNA were used.

RESULTS

TBNA was performed in 49 patients and provided the diagnosis in 85.7%. Conventional techniques led to cytological and histological diagnosis in 80.2% of the cases, and the combination of conventional techniques and TBNA gave a diagnosis in 89.7% (P=.01). Significant differences were observed in extrinsic compression (conventional 37.5%; conventional+TBNA 100%; P=.01), submucosal infiltration (conventional 54.6%; conventional+TBNA 85%; P=.03), and exophytic mass with necrosis (conventional 80%; conventional+TBNA 100%; P=.01). The mean (SD) cost of diagnosis was euros 381.60 (euros 156.53) using conventional techniques and euros 413.25 (euros 112.91) for conventional techniques in combination with TBNA. By adding TBNA, costs decreased for diagnoses of submucosal infiltration, exophytic mass with necrosis and extrinsic compression, although the saving was significant only for extrinsic compression.

CONCLUSION

The diagnostic yield of TBNA is high for endoscopically visible bronchial anomalies suggesting neoplasm, particularly when the lesion is due to extrinsic compression, submucosal infiltration, or exophytic mass with necrosis.

Production and biochemical characterization of the recombinant Boophilus microplus Bm95 antigen from Pichia pastoris

The new antigen Bm95 from the cattle tick Boophilus microplus was recently isolated, cloned and expressed in the methylotrophic yeast Pichia pastoris. The recombinant protein has shown to induce protection in cattle against infestations of B. microplus under controlled and production conditions. In this paper we report the production and large-scale purification of the Bm95 protein, following a simple and cost-effective process. The antigen was obtained highly aggregated, forming particles ranging from 26 to 30 nm and with purity higher than 80%. The process yield was 0.55 g of pure Bm95 protein per liter of culture. The 98% of the primary structure of the recombinant protein was verified by mass spectrometry. Three amino acid changes in comparison with the sequence deduced from cDNA were detected by LC-MS/MS. The antigen was also obtained N-glycosylated, as previously reported for heterologous protein expression in P. pastoris.

New C-band protocol by heat denaturation in the presence of formamide

C-banding techniques detect the presence of constitutive heterochromatin, which is usually located in centromeric regions of chromosomes in the majority of analysed species. The common method for C-banding used over the last 30 years involves treatment with a mild alkali barium hydroxide 5% Ba(OH)2 at 50 degrees C for 5-15 min and subsequent incubation in salt solution (2 x SSC at 60 degrees C for 1 h). We here present a new, easy and reliable technique for C-banding, which basically involves heat denaturation of chromosomal DNA in the presence of formamide and incubation in 2 x SSC at room temperature.

Pericentric satellite DNA sequences in Pipistrellus pipistrellus (Vespertilionidae; Chiroptera)

This paper reports the molecular and cytogenetic characterization of a HindIII family of satellite DNA in the bat species Pipistrellus pipistrellus. This satellite is organized in tandem repeats of 418 bp monomer units, and represents approximately 3% of the whole genome. The consensus sequence from five cloned monomer units has an A-T content of 62.20%. We have found differences in the ladder pattern of bands between two populations of the same species. These differences are probably because of the absence of the target sites for the HindIII enzyme in most monomer units of one population, but not in the other. Fluorescent in situ hybridization (FISH) localized the satellite DNA in the pericentromeric regions of all autosomes and the X chromosome, but it was absent from the Y chromosome. Digestion of genomic DNAs with HpaII and its isoschizomer MspI demonstrated that these repetitive DNA sequences are not methylated. Other bat species were tested for the presence of this repetitive DNA. It was absent in five Vespertilionidae and one Rhinolophidae species, indicating that it could be a species/genus specific, repetitive DNA family.

Recruitment manoeuvres in acute lung injury/acute respiratory distress syndrome

Acute respiratory distress syndrome/acute lung injury is characterised by profound hypoxaemia due to a permeability pulmonary oedema. In this setting, recruitment manoeuvres (RMs) can be a useful tool as adjuncts to lung protective ventilatory strategies to prevent cyclic alveolar stress and avoid alveolar collapse. Many experimental and physiological studies have discussed the use of RMs but only a few heterogeneous clinical experiences have demonstrated the beneficial and deleterious effects that can occur using these manoeuvres. Besides, a lot of questions remain to be answered to find the best way to perform optimal RMs. Further experimental and clinical trials are needed to understand the potential beneficial effects of recruitment manoeuvres when using a protective mechanical ventilation strategy. This paper is a general review of experimental works that support application of recruitment manoeuvres emphasising the clinical studies that have been published to date in acute respiratory distress syndrome patients.

Regulation of insulin receptor substrate-1 in the liver, skeletal muscle and adipose tissue of rats throughout pregnancy

The mechanism responsible for insulin resistance during pregnancy remains unclear. Considerable evidence indicates that insulin receptor substrate-1 could play an important role in insulin sensitivity. It seems possible that the gestational hormonal milieu could affect insulin receptor substrate-1. In the present study, measurements of tyrosine phosphorylation and protein content of insulin receptor substrate-1 and gene expression in the liver, skeletal muscle and adipose tissue in the rat indicated that, during pregnancy, significant changes occurred in these parameters. We found in early gestation that muscle and adipose tissue were highly sensitive to insulin action, because the phosphorylation of insulin receptor substrate-1 is greater than in late gestation. However, in late gestation the tissue most sensitive to insulin action, reflecting insulin receptor substrate-1 phosphorylation, was the liver. Our hypothesis was that these results are connected with the changes in concentrations of estradiol and progesterone observed during pregnancy. It was concluded that the present findings demonstrate that different concentrations of gestational hormones play an important role in insulin sensitivity in this period, and that each tissue responds in the most appropriate manner to guarantee the gestation in its entirety, controlling the phosphorylation of insulin receptor substrate-1 in response to insulin receptor activation.

Melatonin and mammary cancer: a short review

Melatonin is an indolic hormone produced mainly by the pineal gland. The former hypothesis of its possible role in mammary cancer development was based on the evidence that melatonin down-regulates some of the pituitary and gonadal hormones that control mammary gland development and which are also responsible for the growth of hormone-dependent mammary tumors. Furthermore, melatonin could act directly on tumoral cells, as a naturally occurring antiestrogen, thereby influencing their proliferative rate. The first reports revealed a low plasmatic melatonin concentration in women with estrogen receptor (ER)-positive breast tumors. However, later studies on the possible role of melatonin on human breast cancer have been scarce and mostly of an epidemiological type. These studies described a low incidence of breast tumors in blind women as well as an inverse relationship between breast cancer incidence and the degree of visual impairment. Since light inhibits melatonin secretion, the relative increase in the melatonin circulating levels in women with a decreased light input could be interpreted as proof of the protective role of melatonin on mammary carcinogenesis. From in vivo studies on animal models of chemically induced mammary tumorigenesis, the general conclusion is that experimental manipulations activating the pineal gland or the administration of melatonin lengthens the latency and reduces the incidence and growth rate of mammary tumors, while pinealectomy usually has the opposite effects. Melatonin also reduces the incidence of spontaneous mammary tumors in different kinds of transgenic mice (c-neu and N-ras) and mice from strains with a high tumoral incidence. In vitro experiments, carried out with the ER-positive MCF-7 human breast cancer cells, demonstrated that melatonin, at a physiological concentration (1 nM) and in the presence of serum or estradiol: (a) inhibits, in a reversible way, cell proliferation, (b) increases the expression of p53 and p21WAF1 proteins and modulates the length of the cell cycle, and (c) reduces the metastasic capacity of these cells and counteracts the stimulatory effect of estradiol on cell invasiveness; this effect is mediated, at least in part, by a melatonin-induced increase in the expression of the cell surface adhesion proteins E-cadherin and beta(1)-integrin. The direct oncostatic effects of melatonin depends on its interaction with the tumor cell estrogen-responsive pathway. In this sense it has been demonstrated that melatonin down-regulates the expression of ERalpha and inhibits the binding of the estradiol-ER complex to the estrogen response element (ERE) in the DNA. The characteristics of melatonin's oncostatic actions, comprising different aspects of tumor biology as well as the physiological doses at which the effect is accomplished, give special value to these findings and encourage clinical studies on the possible therapeutic value of melatonin on breast cancer.

Synthesis and structural characterization of Be(eta 5-C5Me5)(eta 1-C5Me4H). Evidence for ring-inversion leading to Be(eta 5-C5Me4H)(eta 1-C5Me5)

The mixed-ring beryllocene Be(C5Me5)(C5Me4H), that contains eta 5-C5Me5 and eta 1-C5Me4H rings, the latter bonded to the metal through the CH carbon atom (X-ray crystal structure) reacts at room temperature with CNXyl (Xyl = C6H3-2,6-Me2) to give an iminoacyl product, Be(eta 5-C5Me4H)[C(NXyl)C5Me5] derived from the inverted beryllocene structure Be (eta 5-C5Me4H)(eta 1-C5Me5).