A computational framework for ptychographic reconstructions.

Ptychography is now a well-established X-ray microscopy tool for synchrotron end-stations equipped with a scanning stage and a pixelated detector. Ptychographic phasing algorithms use information from coherent diffraction to deliver quantitative images of the specimen at a resolution higher than the scanning resolution. These algorithms have traditionally been implemented in software on a per-instrument basis in various degrees of user-friendliness and sophistication. Here, we present Ptypy, a ptychography software written with the intention to serve as a framework across the diverse sets of available instruments and usage cases. A distinctive feature of the software is its formalism, which provides a convenient abstraction of the physical model, thus allowing for concise algorithmic implementations and portability across set-up geometries. We give an overview of the supported usage cases, explain the abstraction layer and design principles, and provide a step-by-step guide describing how an algorithm may be realized in a concise and readable manner. The software capabilities are illustrated with reconstructions from visible light and X-ray data.

Ptychographic X-ray nanotomography quantifies mineral distributions in human dentine.

Bones are bio-composites with biologically tunable mechanical properties, where a polymer matrix of nanofibrillar collagen is reinforced by apatite mineral crystals. Some bones, such as antler, form and change rapidly, while other bone tissues, such as human tooth dentine, develop slowly and maintain constant composition and architecture for entire lifetimes. When studying apatite mineral microarchitecture, mineral distributions or mineralization activity of bone-forming cells, representative samples of tissue are best studied at submicrometre resolution while minimizing sample-preparation damage. Here, we demonstrate the power of ptychographic X-ray tomography to map variations in the mineral content distribution in three dimensions and at the nanometre scale. Using this non-destructive method, we observe nanostructures surrounding hollow tracts that exist in human dentine forming dentinal tubules. We reveal unprecedented quantitative details of the ultrastructure clearly revealing the spatially varying mineralization density. Such information is essential for understanding a variety of natural and therapeutic effects for example in bone tissue healing and ageing.

Serum cortisol concentrations in dogs with pituitary-dependent hyperadrenocorticism and atypical hyperadrenocorticism.

BACKGROUND: Atypical hyperadrenocorticism (AHAC) is considered when dogs have clinical signs of hypercortisolemia with normal hyperadrenocorticism screening tests. HYPOTHESIS/OBJECTIVES: To compare cortisol concentrations and adrenal gland size among dogs with pituitary-dependent hyperadrenocorticism (PDH), atypical hyperadrenocorticism (AHAC), and healthy controls. ANIMALS: Ten healthy dogs, 7 dogs with PDH, and 8 dogs with AHAC. METHOD: Dogs were prospectively enrolled between November 2011 and January 2013. Dogs were diagnosed with PDH or AHAC based on clinical signs and positive screening test results (PDH) or abnormal extended adrenal hormone panel results (AHAC). Transverse adrenal gland measurements were obtained by abdominal ultrasound. Hourly mean cortisol (9 samplings), sum of hourly cortisol measurements and adrenal gland sizes were compared among the 3 groups. RESULTS: Hourly (control, 1.4 ± 0.6 µg/dL; AHAC, 2.9 ± 1.3; PDH, 4.3 ± 1.5) (mean, SD) and sum (control, 11.3 ± 3.3; AHAC, 23.2 ± 7.7; PDH, 34.7 ± 9.9) cortisol concentrations differed significantly between the controls and AHAC (P < .01) and PDH (P < .01) groups. Hourly (P < .01) but not sum (P = .27) cortisol concentrations differed between AHAC and PDH dogs. Average transverse adrenal gland diameter of control dogs (5.3 ± 1.2 mm) was significantly less than dogs with PDH (6.4 ± 1.4; P = .02) and AHAC (7.2 ± 1.5; P < .01); adrenal gland diameter did not differ (P = .18) between dogs with AHAC and PDH. CONCLUSIONS AND CLINICAL IMPORTANCE: Serum cortisol concentrations in dogs with AHAC were increased compared to controls but less than dogs with PDH, while adrenal gland diameter was similar between dogs with AHAC and PDH. These findings suggest cortisol excess could contribute to the pathophysiology of AHAC.

[Knowledge of male college students on induced abortion]. / Conhecimento de universitários do sexo masculino sobre aborto provocado.

The purpose of the study was to verify the knowledge of male university students regarding induced abortion. The sample was comprised of 71 male students that corresponded to 70% of the population made up of students from different health related programs at a federal university. Data was collected in August and October of 1998, by means of a questionnaire that was based on two previous exploratory studies. The respondents were 17 to 22 years old, catholic, single and financially dependent. The results demonstrated that a large percentage of male students had knowledge of what an induced abortion was and of its consequences, as well as of the methods used to induce the fetal loss. The respondents expressed a negative opinion about abortion and placed the responsibility for such a decision on the couple. They also indicated that besides the woman, other individuals, such as friends and family members bared some responsibility for the decision to end or not a pregnancy.

[Educational activities on the prevention of AIDS in a municipal basic health unit: participation of a nurse]. / Atividades educativas na prevenção da AIDS em uma rede básica municipal de saúde: participação do enfermeiro.

This is an exploratory descriptive study with a qualitative approach that had as its purpose to characterize the educational activities of the nurses that work in the prevention and control program for sexually transmittable diseases and AIDS in the municipality of Natal, RN. The study ws conducted in the basic health care units with 10 (ten) nurses that implemented educational activities in AIDS prevention. A structured interview was used and content analysis techniques were applied to the data. It was identified that the majority of the nurses understood health education as the transmission of information and that the AIDS prevention program had insufficient actions, lacked structure in the service settings and institutional support by the Municipal Secretariat of Health. The program activities were characterized as traditional limited, sporadic, and lacking human and material resources.

Immunization of Aotus monkeys with recombinant Plasmodium falciparum hybrid proteins does not reproducibly result in protection from malaria infection.

Plasmodium falciparum antigens SERP, HRPII, MSAI, and 41-3 have shown promise as vaccine components. This study aimed at reproducing and extending previous results using three hybrid molecules. Antibody responses were reproduced in Aotus monkeys, but solid protection from a P. falciparum blood-stage challenge that showed an unintendedly enhanced pathogenicity was not observed.

[Are the roles of the nurse specialist and the master of health services the same?]. / O papel do enfermeiro especialista e do mestre nos serviços de saúde é o mesmo?

This study aimed at identifying the role of the nurse with a graduate degree at the service level based on nurses and service directors expectations in health care institutions. A total of 278 nurses and 25 service directors responded to a questionnaire and an instrument was designed to measure their expectations towards the nurse with a postgraduation degree. The results indicate that nurses and service directors hope nurses with a postgraduation degree to be highly qualified to provide care. While service directors express a slight difference in favor of both the master degree and the deep knowledge of the specialty, nurses expectations in relation to it, are a little greater in all aspects. Service directors priorize refresh courses for nurses while nurses priorize specialization courses. The study has implications for a deeper discussion of these professionals functions in service and for the objective of postgraduate education programs in the region.

[Perspective evaluation of the post-graduate courses of the Nursing Department at UFRN (1980-1992)]. / Avaliaçäo e perspectiva dos cursos de pós-graduaçäo lato-sensu do departamento de enfermagem da UFRN (1980-1992).

The purpose of the study was to evaluate the "lato sensu" graduate programs of study of the Department of Nursing in the UFRN, and to know the perspectives of its students and faculty. A total of 67 questionnaires were applied to 14 professors and 53 ex-students. The sources of data were: a survey of the scientific knowledge produced by the faculty; specialization program final reports; partial 1989-1991 program evaluations; and, the final report of the first Graduate Program Evaluation Seminar (1992). Eventhough the results of the evaluation were positive, some aspects of the program were found to need further analysis so that future graduate studies might be improved. These aspects were: revision of the curriculum content, improvement of the space environment, and improvement of the bibliographic resources.

Role of diprotonated phosphate in evoking muscle reflex responses in cats and humans.

Lactic acid and H+ evoke muscle reflexes that raise sympathetic nerve activity. Whether these substances are direct afferent stimulants or markers for the acidification of other substances is unknown. Diprotonated phosphate (H2PO4-), a possible mediator of fatigue, increases as the cell acidifies and phosphate is produced. Its role in evoking muscle reflexes is unknown. We used 31P-nuclear magnetic resonance to measure forearm muscle H+ and H2PO4- and microneurography to measure muscle sympathetic nerve activity (MSNA, peroneal nerve) during a handgrip protocol designed to dissociate H+ from H2PO4-. Ischemic handgrip (50% maximal voluntary contraction x 2 min) was followed by a 1-min rest period during which the muscle was freely perfused. This was followed by a second bout of ischemic handgrip and a 5-min recovery. In seven of eight subjects, MSNA correlated with H2PO4-, whereas it correlated with pH in only one subject. To determine whether muscle reflex responses are evoked by H+, lactic acid, monoprotonated phosphate (HPO4(2-), or H2PO4-, we injected H+, lactate, H2PO4- [all 50 mM in 10 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffered to pH 6], and HPO4(2-) (50 mM, pH 7.5 in 10 mM HEPES) into the arterial supply of the triceps surae of the cat (n = 9) as we measured mean arterial blood pressure (MAP). H2PO4- increased MAP more than HPO4(2-), H+, or lactate (27.1 +/- 3.7 vs. 5.0 +/- 1.3, 4.6 +/- 3.1, and 7.7 +/- 3.2 rise in mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)

Limb congestion and sympathoexcitation during exercise. Implications for congestive heart failure.

During static exercise, heart failure (HF) subjects activate the sympathetic nervous system differently than normal controls. HF causes metaboreceptor desensitization with either enhanced mechanoreceptor activity or central command. In this report, we examined whether increased muscle interstitial pressure, as seen in HF, augments other neural systems. We measured muscle sympathetic nerve activity (MSNA; peroneal nerve) in 10 normals during static exercise (40% maximal voluntary grip) and posthandgrip circulatory arrest (PHG-CA). This was repeated after venous congestion (VC; cuff inflation to 90 mmHg). VC increased forearm volume (plethysmography) by 4.7%. MSNA responses to exercise were greater after VC (150.5 +/- 41.8 vs. 317.3 +/- 69.9 arbitrary units; P < 0.01). However, MSNA responses during PHG-CA were not affected by VC, and 31P nuclear magnetic resonance (n = 5) demonstrated no effect of VC on pH or H2PO4-. Similar effects of VC on MSNA were noted after ischemic exercise (n = 7), excluding flow alterations as the explantation. VC probably sensitized mechanically sensitive afferents since MSNA during involuntary biceps contractions increased after VC (n = 6), and skin sympathetic nerve responses during handgrip, an index of central command, were not increased by VC (n = 6).

Acute and chronic antiarrhythmic efficacy of d-sotalol in patients with sustained ventricular tachyarrhythmias.

To evaluate the clinical efficacy of d-sotalol, 84 patients with a history of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF), who had inducible sustained VT/VT at baseline electrophysiologic study (EPS), were investigated after intravenous (IV) d-sotalol (1.5-2.5 mg.kg-1). A total of 29 additional patients received only oral d-sotalol, (400-600 mg.day-1). Acute success of antiarrhythmic therapy was defined as suppression of inducible sustained VT/VF. The overall success rate of IV d-sotalol was 38% (32/84) after a mean of 4.3 drugs failed to suppress inducibility. A 78% success rate (31/40) was demonstrated in patients who were also assessed after oral d-sotalol. Torsade de pointes type VT was seen in one patient. After 1 year, only 16% of patients with a positive EPS had a recurrence compared to 43% of patients with a negative EPS (P < 0.05). Estimated survival rates were 95 and 88% after 1 and 2 years of follow-up, respectively. Only five of 56 patients discontinued d-sotalol therapy because of adverse effects. IV d-sotalol appears to be an effective antiarrhythmic agent. Its long-term efficacy is predictable on the basis of therapy guided by electrophysiologic testing in patients with refractory ventricular tachyarrhythmias. The efficacy of d-sotalol seems comparable to that reported for d,l-sotalol.

Comparison of the effects of adjuvants and adjuvant doses on the quantitative and qualitative antibody response to selected antigens in New World squirrel monkeys Saimiri sciureus.

The effect of several adjuvants and of adjuvant doses on the quantitative and qualitative antibody response to tetanus toxoid (TT) and a recombinant herpes simplex virus peptide (HSVgD) was evaluated in the New World monkey Saimiri sciureus. All adjuvant formulations were effective in inducing a strong antibody response to these antigens. The qualitative antibody response, as defined by monoclonal antibodies 3A2/G6 and 4G3/B5, was determined. Only 3A2/G6+ antibodies were induced after immunization with HSVgD irrespective of the adjuvant used and after immunization with TT alone. However, both types of antibodies were induced against TT in the presence of the adjuvants tested. These data suggest that both adjuvant and antigens can intervene in driving the quality of the antibody response induced after immunization. Strong antibody response to TT was induced at any adjuvant dose tested, suggesting that lower doses are as effective as higher doses. These findings can have implications on the design of future trials of vaccine candidate constructs in monkeys and eventually in human beings.

Protection of Aotus monkeys from malaria infection by immunization with recombinant hybrid proteins.

On the basis of investigations of the malarial blood-stage antigens SERP, HRPII, and MSAI from Plasmodium falciparum, we chose two Escherichia coli-expressed hybrid proteins containing selected partial sequences of these antigens. Antibodies raised against both hybrid proteins in rabbits and Aotus monkeys recognize the corresponding P. falciparum polypeptides. In two independent trials with 13 animals, immunization of Aotus monkeys with either of the two hybrid proteins administered in a well-tolerated oil-based formulation protected the animals from an experimental P. falciparum infection.

Effect of pH and inorganic phosphate on creatine kinase inactivation: an in vitro 31P NMR saturation-transfer study.

The pseudo-first-order rate constant of rabbit muscle creatine kinase (CK), in the direction of ATP synthesis (kf), was determined by saturation-transfer 31P NMR. When pH was varied between 6.0 and 7.4, kf increased linearly at both 20 degrees C and 37 degrees c. The corresponding flux is very small between pH 6.0 and 6.5, in contrast to previous studies. Up to 50 h exposure of the CK enzyme to high concentrations of inorganic phosphate (Pi), a known inhibitor in certain situations, had negligible effect on enzymatic flux in the physiological pH range. Thus under in vivo conditions, such as in stroke, where pH falls as low as 6.2 and Pi rises to high levels, the rate of the CK reaction may be severely reduced due to pH but not due to high Pi concentrations.

Strategies for the development of an antimalarial vaccine.

Susceptible Aotus monkeys were immunized with Escherichia coli-derived fusion proteins containing partial sequences of the proteins MSAI, SERP, HRPII and with a group of three recombinant antigens isolated by screening with an antiserum raised against the protective 41 kDa protein band. HRPII, the combination of the fusion proteins of the 41 kDa group and a mixture of two sequences of SERP conferred significant protection against a challenge infection with Plasmodium falciparum blood stages. Based on the protective capacity of these recombinant antigens we have expressed two hybrid proteins (MS2/SERP/HRPII and SERP/MSAI/HRPII) in E. coli containing selected partial sequences. In two independent immunization trials it was shown that immunization of Aotus monkeys with either of the two hybrid proteins can protect the animals from an experimental P. falciparum infection.

Protection of Aotus monkeys after immunization with recombinant antigens of Plasmodium falciparum.

The genus Aotus spp. (owl monkey) is one of the WHO recommended experimental models for Plasmodium falciparum blood stage infection, especially relevant for vaccination studies with asexual blood stage antigens of this parasite. For several immunization trials with purified recombinant merozoite/schizont antigens, the susceptible Aotus karyotypes II, III, IV and VI were immunized with Escherichia coli derived fusion proteins containing partial sequences of the proteins MSAI (merozoite surface antigen I), SERP (serine-stretch protein) and HRPII (histidine alanine rich protein II) as well as with a group of recombinant antigens obtained by an antiserum raised against a protective 41 kD protein band. The subcutaneous application (3x) of the antigen preparations was carried out in intact animals followed by splenectomy prior to challenge, in order to increase the susceptibility of the experimental hosts to the parasite. A partial sequence of HRPII, the combination of three different fusion proteins of the 41 kD group and a mixture of two sequences of SERP in the presence of a modified Al(OH)3 adjuvant conferred significant protection against a challenge infection with P. falciparum blood stages (2-5 x 10(6)) i. RBC). Monkeys immunized with the MS2-fusion protein carrying the N-terminal part of the 195 kD precursor of the major merozoite surface antigens induced only marginal protection showing some correlation between antibody titer and degree of parasitaemia. Based on the protective capacity of these recombinant antigens we have expressed two hybrid proteins (MS2/SERP/HRPII and SERP/MSAI/HRPII) in E. coli containing selected partial sequences of SERP, HRPII and MSAI. Antibodies raised against both hybrid proteins in rabbits and Aotus monkeys recognize the corresponding schizont polypeptides. In two independent immunization trials using 13 animals (age 7 months to 3 years) we could show that immunization of Aotus monkeys with either of the two hybrid proteins administered in an oil-based well tolerated formulation protected the animals from a severe experimental P. falciparum (strain Palo Alto) infection.

Coagulation disorders in experimentally induced acute mouse malaria.

The development of coagulation disorders was studied in murine malaria. Plasmodium vinckei was chosen following an initial experiment because onset and duration of parasitemia were more suitable for hemostasiological studies than in the short-lasting infection, caused by P. berghei. Evaluation of the time courses of hematocrit, platelets, antithrombin (AT) III activity, Factor V activity and parasitemia showed a significant decrease in platelets, hematocrit, Factor V and AT III activity during the course of infection. The obtained data strongly suggest the development of a disseminated intravascular coagulation in mice during the terminal phase of murine malaria.

A recombinant hybrid protein as antigen for an anti-blood stage malaria vaccine.

Based on investigations on several blood stage antigens from Plasmodium falciparum we have expressed a hybrid protein in E. coli containing 262 amino acids of the serine-stretch protein SERP and 189 amino acids of the histidine alanine rich protein HRPII. Antibodies raised against the hybrid protein by immunization of rabbits and Aotus monkeys react with both corresponding schizont polypeptides. Two Aotus monkeys immunized with the SERP/HRPII hybrid protein showed only low parasitemias after challenge infection with P. falciparum, compared to the control group. The result suggests that hybrid proteins of this type may be the basis for the development of a malaria vaccine.

Antithrombin III substitution affects survival rate in a murine malaria model.

The effect of AT III substitution on survival time was studied in P. vinkei infected mice. One hundred mice were infected, randomly selected and allocated to two groups of 40 animals each on day 13 after infection. One group was placebo treated, the other group received 3 IU AT III daily on days 13 to 19. Comparison of the survival time in the log rank test showed a prolongation of the median survival time (5 versus 9 days, P less than 0.01). It is concluded that AT III might be beneficial in the treatment of severe malaria cases.