Genome-wide association study and functional analyses for clinical and subclinical ketosis in Holstein cattle

Ketosis is one of the most frequent metabolic diseases in high-yielding dairy cows and is characterized by high concentrations of ketone bodies in blood, urine, and milk, causing high economic losses. The search for polymorphic genes, whose alleles have different effects on resistance to developing the disease, is of extreme importance to help select less susceptible animals. The aims of this study were to identify genomic regions associated with clinical and subclinical ketosis (β-hydroxybutyrate concentration) in North American Holstein dairy cattle and to investigate these regions to identify candidate genes and metabolic pathways associated with these traits. To achieve this, a GWAS was performed for 4 traits: clinical ketosis lactation 1, clinical ketosis lactation 2 to 5, subclinical ketosis lactation 1, and subclinical ketosis lactation 2 to 5. The estimated breeding values from 77,277 cows and 7,704 bulls were deregressed and used as pseudophenotypes in the GWAS. The top-20 genomic regions explaining the largest proportion of the genetic variance were investigated for putative genes associated with the traits through functional analyses. Regions of interest were identified on chromosomes 2, 5, and 6 for clinical ketosis lactation 1; 3, 6, and 7 for clinical ketosis lactation 2 to 5; 1, 2, and 12 for subclinical ketosis lactation 1; and 20, 11, and 25 for subclinical ketosis lactation 2 to 5. The highlighted genes potentially related to clinical and subclinical ketosis included ACAT2 and IGF1. Enrichment analysis of the list of candidate genes for clinical and subclinical ketosis showed molecular functions and biological processes involved in fatty acid metabolism, lipid metabolism, and inflammatory response in dairy cattle. Several genomic regions and SNPs related to susceptibility to ketosis in dairy cattle that were previously described in other studies were confirmed. The novel genomic regions identified in this study aid to characterize the most important genes and pathways that explain the susceptibility to clinical and subclinical ketosis in dairy cattle.

COVID-19 Response in Latin America

Effective management of a pandemic due to a respiratory virus requires public health capacity for a coordinated response for mandatory restrictions, large-scale testing to identify infected individuals, capacity to isolate infected cases and track and test contacts, and health services for those infected who require hospitalization. Because of contextual and socioeconomic factors, it has been hard for Latin America to confront this epidemic. In this article, we discuss the context and the initial responses of eight selected Latin American countries, including similarities and differences in public health, economic, and fiscal measures, and provide reflections on what worked and what did not work and what to expect moving forward.

ERRα promotes breast cancer cell dissemination to bone by increasing RANK expression in primary breast tumors

Bone is the most common metastatic site for breast cancer. Estrogen-related-receptor alpha (ERRα) has been implicated in cancer cell invasiveness. Here, we established that ERRα promotes spontaneous metastatic dissemination of breast cancer cells from primary mammary tumors to the skeleton. We carried out cohort studies, pharmacological inhibition, gain-of-function analyses in vivo and cellular and molecular studies in vitro to identify new biomarkers in breast cancer metastases. Meta-analysis of human primary breast tumors revealed that high ERRα expression levels were associated with bone but not lung metastases. ERRα expression was also detected in circulating tumor cells from metastatic breast cancer patients. ERRα overexpression in murine 4T1 breast cancer cells promoted spontaneous bone micro-metastases formation when tumor cells were inoculated orthotopically, whereas lung metastases occurred irrespective of ERRα expression level. In vivo, Rank was identified as a target for ERRα. That was confirmed in vitro in Rankl stimulated tumor cell invasion, in mTOR/pS6K phosphorylation, by transactivation assay, ChIP and bioinformatics analyses. Moreover, pharmacological inhibition of ERRα reduced primary tumor growth, bone micro-metastases formation and Rank expression in vitro and in vivo. Transcriptomic studies and meta-analysis confirmed a positive association between metastases and ERRα/RANK in breast cancer patients and also revealed a positive correlation between ERRα and BRCA1mut carriers. Taken together, our results reveal a novel ERRα/RANK axis by which ERRα in primary breast cancer promotes early dissemination of cancer cells to bone. These findings suggest that ERRα may be a useful therapeutic target to prevent bone metastases.

The Diatraea Complex (Lepidoptera: Crambidae) in Colombia's Cauca River Valley: Making a Case for the Geographically Localized Approach

The sugarcane stem borers Diatraea saccharalis (Fabricius) and D. indigenella Dyar & Heinrich are common pests of sugarcane crops in Colombia's Cauca river valley (CRV). In 2012, however, D. tabernella Dyar was recorded for the first time in northern CRV and just 1 year later, D. busckella Dyar & Heinrich was detected, also for the first time, in central CRV. The Diatraea outbreak in the CRV was studied, its distribution and population in the region was analyzed, and levels of larval parasitism were observed. During the study of the outbreak, Diatraea species in the CRV were characterized based on the morphology of larval, pupal, and adult stages. Keys to the identification of Diatraea in the CRV based on male genitalia and pupa are provided. Pupal cephalic horns and lateral lobes were discovered as new, reliable characteristics to separate the species at the pupal stage. We suggest biological control program modifications to decrease economic impact and studies at geographically localized levels to better understand the dynamics between the pest species and their parasitoids.

Genetic analysis of feet and leg conformation traits in Nelore cattle

Feet and leg conformation scores are important traits in beef cattle because they encompass a wide range of locomotion disorders that can lead to productive and reproductive losses. Thus, the study of feet and legs in beef cattle is essential for evaluating possible responses to selection focusing on minimizing economic losses caused by the occurrence of feet and leg problems. The aim of this study was to estimate variance components for feet and leg conformation traits in Nelore cattle. The data set contained records of approximately 300,000 animals that were born between 2000 and 2013. These animals belonged to the commercial beef cattle breeding program of the CRV Lagoa (). Feet and legs were evaluated by assigning visual scores at 2 different time points: feet and leg evaluated as a binary trait (FL1), measured at yearling (about 550 d of age) to identify whether (or not) an animal has feet and leg defects, and feet and leg score (FL2), ranging from 1 (less desirable) to 5 (more desirable) was assigned to the top 20% of animals according to the selection index adopted by the beef cattle breeding program, which was measured 2 to 5 mo after the yearling evaluation. The FL1 and FL2 traits were analyzed together with yearling weight (YW). The (co)variance components and breeding values were estimated by Bayesian inference using 2-trait animal models. The posterior means (standard errors) of the heritabilities for FL1, FL2, and YW were 0.18 (0.04), 0.39 (0.07), and 0.47 (0.01), respectively. The results indicate that the incidence of feet and leg problems in this population might be reduced by selection. The genetic correlation between FL1 and FL2 (-0.47) was moderate and negative as expected because the classification score that holds up each trait has opposite numerical values. The genetic trends estimated for FL1 and FL2 (-0.042 and 0.021 genetic standard deviations per year, respectively) were favorable and they indicate that the independent culling strategy for feet and leg problems promotes favorable changes and contributes to the genetic progress of these traits in the population under study.

Orange Peel Oxidative Gasification on Ni Catalysts Promoted with CaO, CeO2 or K2O

Orange peel can be considered as an attractive raw material to be gasified for hydrogen or syngas production. In this work, the catalytic evaluation of several silica-supported nickel catalysts in the oxidative degradation of waste orange peel is reported. It was found that the catalytic gasification with the K2O-Ni/silica catalyst produces more hydrogen than the non-catalytic route at 600 degrees C. Surprisingly, a significant amount of ethene was obtained with the CeO2-Ni/silica catalyst, which was explained in terms of an oxidative dehydrogenation reaction of ethane formed during biomass or tar decomposition.

La relación de <i>Helicobacter pylori</i> con la displasia y el cáncer gástrico en Costa Rica

Se comparó la incidencia de labaéteria Hdicobacter pylori en un lugar pe baja incidencia de cáncer gástrico, Poás ( 15. 13%) y otro de incidencia muy alta, Puriscal (83. 53%) Se eligió a 185 adultos de cada cantón, similares en edad y sexo y se practicó un estudio serológico para buscar anticuerpos IgG para H. pylori, y una gastroscopía para tomar dos biopsias por caso. Los resultados no apoyan la existencia de una fuerte relación entre H. pylori y cáncer gástrico

Maternal effects shape dynamic trajectories of reproductive allocation in the ladybird Coleomegilla maculata

We followed lifetime trajectories of reproductive allocation in Coleomegilla maculata females of three different size classes produced by rearing beetles on three different daily larval feeding regimes (30 min, 6 h or ad libitum access to eggs of Ephestia kuehniella). We hypothesized that small females would produce fewer and smaller eggs than larger females and that reproductive effort would decline with female age. Females were mated with a male from the same treatment and then isolated with ad libitum food for their entire adult lives. Egg size increased over time in all treatments; small females started off laying the smallest eggs, but increased egg size more rapidly than larger females, until all treatments converged on a similar egg size around the 20th day of oviposition. Large females realized a larger proportion of their fecundity early in life, but smaller females increased daily fecundity over time. Reproductive effort (egg mass/body mass) did not decline over 30 oviposition days; it remained constant in large females, but increased among small and medium females, suggesting gradual compensation for larval food deprivation. An increase in egg size with maternal age may be an adaptive strategy to maximize fitness on ephemeral patches of aphid prey, assuming females reproduce in a single aphid outbreak and that offspring produced later in the aphid cycle experience greater competition and risk of mortality compared to those produced earlier. We demonstrate for the first time in Coleoptera that dynamic changes in both egg size and number occur as a function of female age and illustrate that such changes are constrained by larval feeding histories via their effects on maternal body size.

C6 knock-out mice are protected from thrombophilia mediated by antiphospholipid antibodies

BACKGROUND

Complement activation plays a role in pathogenesis of the antiphospholipid syndrome (APS), but the involvement of the C5b-9 membrane attack complex (MAC) is unknown. Here we studied the effects of human polyclonal antiphospholipid (aPL) antibodies on thrombosis and tissue factor (TF) up-regulation in C6 deficient (C6(-/-)) mice.

METHODS

C6(-/-) mice or the wild-type C3H/HeJ (C6(+/+)) mice were injected twice with IgG-APS (n = 2) or IgM-APS (n = 1) isolated from APS patients or with the corresponding control immunoglobulins (Igs) of normal human serum, (NHS) (IgG-NHS or IgM-NHS). Then, the sizes of induced thrombi in the femoral vein were determined 72 hours after the first injection. Tissue factor was determined in homogenates of carotid arteries and in peritoneal macrophages.

RESULTS

Thrombus sizes were significantly larger in C6(+/+) treated with IgG-APS1 or with IgG-APS2 or with IgM-APS when compared with C6(+/+) mice treated with IgG-NHS or with IgM-NHS, respectively. The sizes of thrombi were significantly smaller in the C6(-/-) mice injected with IgG-APS1, IgG-APS2 or IgM-APS (p < 0.001), compared to their C6(+/+) counterparts showing an important abrogation of thrombus formation in mice lacking C6. The TF expression and activity in the C6(-/-) mice treated with IgG-APS or IgM-APS were diminished when compared to C3H/HeJ (C6(+/+)) mice treated with the same Igs. All mice injected with IgG-APS and IgM-APS had medium-high titers of anticardiolipin (aCL) and anti-β(2)glycoprotein I (aβ(2)GPI) antibodies.

CONCLUSIONS

These data indicate that the C6 component of the complement system mediates aPL-thrombogenic effects, underscoring an important pathogenic mechanism and indicating the possibility of inhibiting complement to ameliorate APS-related manifestations.

Compromised quality of maternal healthcare in a market economy: Medellín, Colombia 2008-2009

Objective: To analyze the quality of the maternal health services in Medellín city, Colombia within the context of the Social Security System in Health from the perspective of the mothers, physicians and nurses involved in the provision of these services. Methodology: A qualitative study was carried out, during which 24 individual interviews were conducted to key doctors and nurses, who work in health institutions that providing maternal care. Also three focus groups with mothers were conducted. The data analysis was carried out using a systematic and carefully coding and categorization process. Findings: In spite of the fact that municipal policies have been put in place to improve maternity care, mother and pregnant women face problems with health services. Findings suggests that the strategies put in place by these health institutions to decrease labor costs, the administrative barriers, the low tariffs of the obstetric services paid by the health insurers within and competitive market, and the focus on getting financial profitability, are aspects that affecting quality of maternal care.

In vivo inhibition of antiphospholipid antibody-induced pathogenicity utilizing the antigenic target peptide domain I of beta2-glycoprotein I: proof of concept

SUMMARY OBJECTIVES

In the antiphospholipid syndrome (APS), the immunodominant epitope for the majority of circulating pathogenic antiphospholipid antibodies (aPLs) is the N-terminal domain I (DI) of beta(2)-glycoprotein I. We have previously shown that recombinant DI inhibits the binding of aPLs in fluid phase to immobilized native antigen, and that this inhibition is greater with the DI(D8S/D9G) mutant and absent with the DI(R39S) mutant. Hence, we hypothesized that DI and DI(D8S/D9G) would inhibit aPL-induced pathogenicity in vivo.

METHODS

C57BL/6 mice (n = 5, each group) were injected with purified IgG derived from APS patients (IgG-APS, 500 microg) or IgG from normal healthy serum (IgG-NHS) and either recombinant DI, DI(R39S), DI(D8S/D9G), or an irrelevant control peptide (at 10-40 microg). Outcome variables measured were femoral vein thrombus dynamics in treated and control groups following standardized vessel injury, expression of vascular cell adhesion molecule-1 (VCAM-1) on the aortic endothelial surface, and tissue factor (TF) activity in murine macrophages.

RESULTS

IgG-APS significantly increased thrombus size as compared with IgG-NHS. The IgG-APS thrombus enhancement effect was abolished in mice pretreated with recombinant DI (P

CONCLUSION

Our findings in this proof-of-concept study support the development of recombinant DI or the novel variant DI(D8S/D9G) as a potential future therapeutic agent for APS.

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Key Words Collapse

MESH Headings

• Animals
• Antibodies, Antiphospholipid/immunology
• Antibodies, Antiphospholipid/physiology
• Enzyme-Linked Immunosorbent Assay
• Macrophages, Peritoneal/metabolism
• Mice
• Mice, Inbred C57BL
• Thromboplastin/metabolism
• beta 2-Glycoprotein I/chemistry
• beta 2-Glycoprotein I/metabolism

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Grants

• R01 AR056745 NIAMS NIH HHS
• Arthritis Research UK

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Simple approach to prenatal diagnosis of transposition of the great arteries

OBJECTIVE

To analyze the most relevant anomalies, seen in a sequential segmental transverse views approach to imaging the fetal heart, that provide clues to the diagnosis of complete transposition of the great arteries (TGA).

METHODS

We reviewed retrospectively all the cases of isolated TGA diagnosed in our center or submitted for a second opinion through the spatio-temporal image correlation (STIC) telemedicine (TELE-STIC) program. Only transverse cardiac sweeps were obtained. Digital video clips and STIC volumes were reviewed. The abnormal features on four-chamber, five-chamber, three-vessel (3V) and three vessels and trachea (3VT) views were analyzed.

RESULTS

The study population consisted of eight fetuses with TGA with normal extracardiac anatomy. The gestational age ranged from 13 to 32 (mean, 23) weeks. The maternal age ranged from 25 to 42 (mean, 32) years. A normal four-chamber view was seen in seven cases. Only one case demonstrated a significant ventricular septal defect. At the level of the five-chamber view a straight course arterial vessel arose from the left ventricle with lateral branches in all fetuses. In the 3V view, the ascending aorta was seen reaching more anteriorly than was the pulmonary artery in six cases. At the level of the 3VT view, two vessels (transverse aortic arch and superior vena cava) rather than three were seen in all cases.

CONCLUSION

Our proposed sequential segmental approach to imaging the fetal heart apparently allows, in five-chamber and 3VT views, clear and confident signs to be detected that aid diagnosis of TGA.

Distribution and enrichment evaluation of heavy metals in Mejillones Bay (23 degrees S), Northern Chile: geochemical and statistical approach

A suite of 36 surface sediment samples, taken between 10 and 100 m water depth in Mejillones Bay (Northern Chile), were analyzed for mineralogy, grain size, total organic carbon, Al, and heavy metal content (Cd, Zn, Ni, Mn, V, Mo). Quartz and feldspars were the main lithogenic minerals and carbonate the predominant biogenic mineral. Sediments were fine sands in the shallow zone and organic silt in the deeper zone. Enrichment Factor and Factor Analysis approach showed that the presence of Mn in the marine sediment of Mejillones is due to a partial influence of continental input, while all other metals are not supported by lithogenic debris. Although all metals showed high concentrations in the marine sediment of Mejillones Bay, comparison between metal concentration in surface sediments and preindustrial levels in this bay, show that present values agree with natural levels.

Prenatal diagnosis of congenital heart disease using four-dimensional spatio-temporal image correlation (STIC) telemedicine via an Internet link: a pilot study

OBJECTIVE

To assess whether the spatio-temporal image correlation (STIC) acquisition technique can be taught to a general obstetrician by e-mail; whether STIC volume datasets can be transmitted over the Internet; and whether STIC volume datasets analyzed offline at a remote setting can be used to confirm or exclude major cardiac defects (TELE-STIC).

METHODS

This was a prospective study involving 50 pregnant women with gestational ages ranging between 20 and 36 weeks. These patients were selected by two general obstetricians (operators) working in geographically remote areas of Chile. Although both obstetricians were users of equipment capable of four-dimensional (4D) ultrasound with STIC, they lacked skill in the performance of fetal cardiac examination. A dedicated web disk was created to upload the acquired volume datasets using an Internet broadband connection. Offline analysis was performed by a single investigator experienced in fetal echocardiography (the administrator).

RESULTS

A telemedicine link via the Internet was possible in all cases. Seventy-seven volume datasets were sent to the web server. A complete cardiac examination according to set criteria was achieved by the administrator in 86% of the cases scanned by one operator and 95% of the cases scanned by the other operator. Three patients had cardiac defects confirmed postnatally, two fetuses had extracardiac anomalies and one fetus had a suspected cardiac defect unconfirmed by second-opinion TELE-STIC. There were two isolated major congenital heart defects. Both patients were given advice by e-mail and teleconference using a web camera about the likely outcome and benefits of scheduling in utero transport to a tertiary care center.

CONCLUSIONS

STIC volumes can be obtained by operators inexperienced in fetal echocardiography, transmitted via the Internet, and their analysis enables recognition of most of the structures and views necessary to assess fetal cardiac anatomy. The preliminary use of TELE-STIC allowed us to demonstrate that some intracardiac anomalies can be ruled out and others confirmed, allowing perinatal management to be tailored accordingly.

Modulation by PKA of the hyperpolarization-activated current (Ih) in cultured rat olfactory receptor neurons

The hyperpolarization-activated Ih channel is modulated by neurotransmitters acting through the cAMP messenger system. In rat olfactory receptor neurons (ORNs), dopamine, by inhibition of adenylyl cyclase, shifts the voltage of half-maximal activation (V1/2) of Ih to more negative potentials and decreases Ih maximal relative conductance. Whether these effects result from a phosphorylation-dependent mechanism is unclear. Therefore, we used whole-cell patch-clamp recording techniques to study cAMP-dependent phosphorylation via PKA on Ih in rat ORNs. General protein kinase inhibition (50 nM K252a) produced a hyperpolarizing shift in Ih V1/2 and decreased Ih maximal conductance. Specific inhibition of PKA with H-89 (500 nM) also shifted the V1/2 of Ih to more negative potentials, and, in some cells, decreased Ih maximal conductance. PKA-mediated phosphorylation (cBIMPS, 50 mM) shifted Ih V1/2 more positive, modulated the kinetics of Ih channel activation and increased Ih peak current amplitude. Internal perfusion of the catalytic subunit of PKA (84 nM) also shifted Ih V1/2 positive and this shift was blocked by co-perfusion with PKI (50 nM). These results show that in rat ORNs, the voltage dependence of Ih activation can be modulated by PKA-dependent phosphorylation. We also show that PKA and other protein kinases may be involved in the regulation of Ih maximal conductance. Our findings suggest that changes in the phosphorylation state of ORNs may affect resting properties as well as modulate odor sensitivity.

An alternative to sutures

Cyanoacrylate tissue adhesives are used in numerous settings to close wounds without the use of sutures. The product and its use for closing chest tube wounds is discussed.

Use of osmotically active agents to alter optical properties of tissue: effects on the detected fluorescence signal measured through skin

BACKGROUND AND OBJECTIVE

Hyper-osmotic chemical agents were used to study the effects of transient tissue scattering on the remitted fluorescence emission intensity from a target placed under a tissue sample.

STUDY DESIGN/MATERIALS AND METHODS

A fluorescent film was placed underneath in vitro and in vivo samples of hamster skin, and the remitted fluorescent signal traveling to the tissue surface was monitored over time as the tissue was treated with an osmotically active agent.

RESULTS

The detected fluorescent signal increased as the scattering in tissue samples was substantially reduced. The increase was greater for dimethyl sulfoxide than glucose or glycerol. It was not statistically different between in vivo skin and in vitro skin.

CONCLUSION

The study shows how chemical agents can be used to improve the detected signal for a specific optical application. It could be useful in a number of optical therapeutic and diagnostic applications that can benefit from an increase in the penetration depth of light.

Renal proximal tubular cell growth and differentiation are differentially modulated by renotropic growth factors and tyrosine kinase inhibitors

BACKGROUND

The renotropic growth factors (GFs), hepatocyte GF (HGF), epidermal GF (EGF), and insulin-like GF-I (IGF-I) accelerate renal regeneration in animal models after toxic or ischemic injury. These GFs initiate their biological effects on renal tubular cells by interaction with specific transmembrane receptor tyrosine kinases.

MATERIALS AND METHODS

In the proximal tubular cell line PT-1, the biological effects of HGF, EGF, and IGF-I and the growth-inhibitory effects of different tyrosine kinase inhibitors (TKIs) were investigated. Receptor binding and tyrosine kinase phosphorylation were determined by ligand binding studies and Western blot analysis.

RESULTS

HGF, EGF, and IGF-I bound with nanomolar affinity to their specific cell membrane receptor tyrosine kinases. In contrast to EGF or IGF-I, HGF induced a variety of cell morphological changes, including cell scattering, formation of tubular structures, and expression of long microvilli on the apical cell membrane. HGF was a 10-fold more potent and more effective growth promoter than EGF or IGF-I. Among the TKIs tested, the mitogenic effect of HGF could be more specifically inhibited by emodin and tyrphostin, that of EGF by methyl-2,5-dihydroxycinnamate, lavendustin A, and genistein, and that of IGF-I by geldanamycin.

CONCLUSIONS

In contrast to EGF and IGF-I, HGF stimulated both growth and differentiation of renal proximal tubular cells, demonstrating the amazing biological potency of this renotropic growth factor. Selective TKIs may be a promising approach to modulate diseases with abnormalities in protein kinase signalling pathways such as renal cell carcinoma.

The effect of repeated controlled ovarian stimulation in donors

BACKGROUND

The effect of repeated controlled ovarian stimulation in young, healthy women who consented to donate their oocytes was assessed through a retrospective study.

METHODS AND RESULTS

Between March 1994 and February 2000, 284 donors consented to at least two controlled ovarian stimulation cycles, with four donors undergoing up to nine cycles. Through an intra-group analysis we studied the oocyte retrieval rate, controlled by the duration and doses of stimulation, as well as the interval between cycles, finding that the number of retrieved oocytes was maintained during repeated controlled ovarian stimulation cycles. The oocyte quality, assessed as fertilization, implantation and pregnancy rates, was similar through five repeated controlled ovarian stimulation cycles. The same result was obtained when the interval in days was analysed as a continuous variable or categorized in <90 and > or =90 days.

CONCLUSIONS

The analysis of the data suggests that successive stimulation cycles do not impair ovarian response in terms of quantity and quality of the oocytes obtained in this group of women. Furthermore, the interval between cycles does not influence the result of the stimulations.

Use of an agent to reduce scattering in skin

BACKGROUND AND OBJECTIVE

A method to increase light transport deeply into target areas of tissue would enhance both therapeutic and diagnostic laser applications. The effects of a hyperosmotic agent on the scattering properties of rat and hamster skin were investigated.

STUDY DESIGN/MATERIALS AND METHODS

A hyperosmotic agent, glycerol, was applied in vitro and in vivo to rat and hamster skin to assess the changes in tissue optical properties. Changes in the reduced scattering coefficient after application of the agent in vitro to rat skin and after the skin has been rehydrated were assessed to evaluate the effect of the agent on tissue.

RESULTS

Experimental results showed a transient change in the optical properties of in vitro rat skin. A 50% increase in transmittance and decrease in diffuse reflectance occurred within 5-10 min after the introduction of anhydrous glycerol. In addition, reduction of light scattering with this technique increased depth of visibility with optical coherence tomography. Injection of glycerol under the skin allowed in vivo visualization of blood vessels.

CONCLUSIONS

The application of the agent reduces the amount of refractive mismatch found in the tissue and markedly reduces random scattering, thereby making the skin less turbid for visible wavelengths for a controlled period of time.

Pulsed laser-induced thermal damage in whole blood

An investigation of the effects of laser irradiation with a wavelength of 532 nm and pulse duration of 10 ms on whole blood was performed in vitro. Threshold radiant exposures for coagulation were quantified and transient radiometric temperatures were measured. The progression of effects with increasing radiant exposure--from evaporation to coagulation-induced light scattering to aggregated coagulum formation to ablation--is described. Results indicate that coagulation and ablation occur at temperatures significantly in excess of those assumed in previous theoretical studies. An Arrhenius rate process analysis based on hemoglobin data indicates good agreement with experimental results.

An alternative to sutures

Cyanoacrylate tissue adhesives are used in numerous settings to close wounds without the use of sutures. The product and its use for closing chest tube wounds is discussed.

Laser fluence for permanent damage of cutaneous blood vessels

Treatment of vascular disorders may be improved by a more thorough understanding of laser-blood vessel interaction. In this study, the probability of permanent damage to a given type and size of blood vessel was determined as a function of fluence at the top (superficial edge) of the vessel lumen. A 532 nm wavelength, 10 ms pulse duration, 3 mm spot size laser was used to perform approximately 250 irradiations of subdermal blood vessels in the hamster dorsal skin flap preparation. The radiant exposure required for a 50% probability of permanent damage was calculated using a probit analysis of experimental results. Threshold radiant exposure increased with larger blood vessel diameters and was greater for arterioles than venules. Monte Carlo modeling of a typical blood vessel geometry revealed that fluence at the top of the blood vessel lumen was amplified by a factor of approximately 2.4 over tissue surface radiant exposure, due to light scattering in the tissue and internal reflection at the skin-air interfaces.

A method for maintaining odor-responsive adult rat olfactory receptor neurons in short-term culture

We report a culture system requiring the addition of freshly made ascorbic acid to the medium, that supports the short-term survival of adult rat olfactory receptor neurons. The cultured neurons exhibit typical voltage-gated currents and are responsive to application of odorants.

Dopamine modulates inwardly rectifying hyperpolarization-activated current (Ih) in cultured rat olfactory receptor neurons

The presence of dopamine receptors in olfactory receptor neurons (ORNs) suggests that odor sensitivity may be modulated by neurotransmitters at the level of primary sensory neurons. Using standard patch-clamp techniques on rat ORNs, we found that 1 microM dopamine, 500 microM SQ 22536 (SQ, an adenylyl cyclase inhibitor), 20 and 50 microM quinpirole (a selective dopamine D2 receptor agonist), and 1 mM adenosine 3', 5'-cyclic monophosphate (cAMP) modulate the hyperpolarization-activated current Ih. On hyperpolarizing from a holding potential of -58 mV, a small Cs+-sensitive inwardly rectifying current (Ih) was observed. Increases in extracellular K+ increased Ih amplitude without shifting its voltage dependence of activation, whereas increases in temperature produced an increase in Ih amplitude and a hyperpolarizing shift in the activation curve. Application of 1 microM dopamine reversibly shifted Ih activation to more negative potentials and decreased Ih current amplitudes. These effects were blocked by concomitant application of dopamine with sulpiride, a selective dopamine D2 receptor antagonist. The effects of dopamine were mimicked by quinpirole. Quinpirole (20 microM) decreased Ih current amplitude, but was without effect on Ih voltage dependence of activation. However, 50 microM quinpirole produced both a reduction of Ih peak currents and a hyperpolarizing shift in the activation curve for Ih. External application of the adenylyl cyclase inhibitor SQ 22536 produced a reversible decrease in peak currents but had no effect on Ih voltage dependence of activation, whereas internal application of cAMP shifted Ih activation to more depolarized potentials. Because Ih modulates cell excitability and spike frequency adaptation, our findings support a role for dopamine in modulating the sensitivity and output of rat ORNs to odorants.

Capillary electrophoresis separation of the new anti-AIDS agents 9-(2-phosphonylmethoxyethyl)adenine and 9-(2-phosphonylmethoxyethyl)-2,6-diaminopurine in mixtures with some monoribonucleotides or the most common deoxynucleotides

The present work describes an electrophoretic method for the separation and determination of the new antivirals, 9-(2-phosphonylmethoxyethyl)adenine (PMEA) and 9-(2-phosphonylmethoxyethyl)-2,9-diaminopurine (PMEDAP) in model mixtures with some monoribonucleotide isomers (3'-AMP, 2'-CMP, 3'-CMP, 3'-GMP, 2'-GMP, 3'-UMP, 5'-GMP, and 5'-UMP) or with the most common deoxynucleotides (dCMP, dCDP, dCTP, dTMP, dTDP, dTTP, dGMP, dGDP, dGTP, dAMP, dADP, dATP). A fused-silica capillary tube, 75 microm ID, 67.8 cm total length (60.3 cm length to the detector), with detection at 210 nm was employed. A hydrodynamic injection for 10 s (1.5 psi vacuum) was utilized to introduce the sample, and 30 kV voltage was applied for the separation. The complete separation of PMEA and PMEDAP from the mononucleotide isomers and deoxynucleotide mixtures is possible in less that 10 min and 25 min, respectively, using 20 mM borate buffer, pH 9.9, with the addition of 10 mM beta-cyclodextrin. Efficiencies of more than 120 000 and resolution higher than 1.9 were reached for each of the compounds studied. This capillary electrophoretic procedure opens the possibility for future determination of PMEA and PMEDAP in cell pool samples.

[The relation of Helicobacter pylori with dysplasia and stomach neoplasms in Costa Rica]

Occurrence of the bacterium Helicobacter pylori was compared for two Costa Rican sites with contrasting levels of gastric cancer incidence, Poás (incidence 15.13%) and Puriscal (83.53%). A sample of 185 adults of similar age and sex proportions was studied in each site, using both H. pylori antiserum tests and gastroscopy to collect two biopsies per case. No clear association between H. pylori and gastric cancer was found.

Determination of drugs used as anti-Parkinson's disease drugs in urine and serum by capillary electrophoresis

A new capillary electrophoresis method to determine simultaneously eight of the most important anti-Parkinson's disease compounds has been developed. The generic names of the drugs studied are benactyzine (BA), trihexyphenidyl (TP), fenpiverin (FP), diphemin (DF), scopolamine (BL), adiphenine (TS), diethylaminoethylester 1-phenylcyclopentane-1-carboxylate (EKK), and diethylaminoethylester tetramethoxydiphenylacetate (EKO). An untreated fused-silica capillary tube (75 microns i.d., 57 cm total length, 49.5 cm length to the detector) was used with detection at 190 nm. The optimal separation conditions were 50 mM phosphate buffer (pH 2.7) with 7 mM-beta-cyclodextrin, electrokinetic injection for 15 sec at 5 kV, temperature 25 degrees C, and 15-20 kV separation voltage. Complete separation of all compounds was achieved in less than 16 min. The procedure was applied for the determination in urine and serum. The limits of detection (LOD, S/N = 3) for serum were 209 (FP), 234 (EKO), 168 (DF), 182 (BA), 168 (TP), 220 (BL), 174 (TS), and 163 (EKK) ppb. The method can be used for the therapeutic drug monitoring of these central active cholinolytics in clinical laboratories.

Capillary zone electrophoresis determination of thyreostatic drugs in urine

In this work, a new capillary zone electrophoresis (CZE) method has been developed for the analysis of thyreostatic drugs (TD) such as methylthiouracil (MTU), propylthiouracil (PTU), and thiouracil (TU) in urine specimens. An untreated fused-silica capillary tube (75 microns i.d., 57 cm total length, 49.5 cm length to the detector) was used in all of the experiments. Optimal conditions were found using 50 mM borate buffer, pH 7.6, applied voltage 15 kV, 25 degrees C, and 30 sec of hydrodynamic injection. UV detection at 276 nm was employed. Ethylacetate extraction of the compounds was made before the analysis of each urine sample. An electrostacking procedure to increase the sensitivity was applied. The method developed was used for the analysis of several thousands of samples as part of a veterinary control procedure (Institute for State Control of Veterinary Biological and Medicaments, Brno, Czech Republic). The following detection limits were reached: 0.3 ppm (PTU and MTU) and 0.5 ppm (TU). The standard deviation for PTU, MTU, and TU determination was 1.12, 0.98, and 3.8% rel., respectively.

Limits of variation of fiber distribution in the sural nerve of man

Although the sural nerve is the most extensively studied nerve in man, there is a dearth of data regarding the normal variations in the size-frequency distribution of axons in normal subjects; criteria for assessing the normality of a given individual are not available. Therefore, in everyday practice, the surgical pathologist may meet with difficulty in interpreting the biopsy of one particular individual, in whom the distribution is slightly different from the curves published. The object of this work is to detect the normal limits of variation in the distribution of diameters of myelinated and unmyelinated fibers in normal subjects and to establish the criteria that permit the calculated curves to be used in everyday clinical practice. Normal sural nerves of 19 patients were analyzed. Ages ranged between 18 months and 55 years. Morphometric analysis was performed with the Histoscan X automatic image processing analyzer, and, for statistical analysis, mixtures of lognormal distributions were fitted and tested with Pearson's statistics. Nerves of three diabetic patients were used for testing the method. They were clearly classified as abnormal. The curves, therefore, have been proven useful for everyday surgical pathology practice.

Direct determination of procainamide and N-acetylprocainamide by capillary zone electrophoresis in pharmaceutical formulations and urine

In this work a new sensitive capillary zone electrophoresis method for the direct determination of procainamide (PA) and N-acetylprocainamide (NAPA) in pharmaceutical formulations and urine samples without any extraction and/or preconcentration steps has been developed. The determination was carried out in a fused-silica capillary of 43.5 cm (35.9 cm length to the detector) x 0.75 micron J.D. Phosphate 0.05 M buffer was used as the background electrolyte and 10 kV separation voltage was applied. The separation of PA and NAPA is possible in a wide range of pH from 1.7 to 9.7. However, in order to avoid the effect of the urine matrix, it is optimal to work at pH 7.7. The determination of PA and NAPA takes less than 5 min while high resolution is achieved. The detection limits obtained, 1.235 micrograms/ml and 0.359 microgram/ml for PA and NAPA respectively, are lower than those for GC method normally reported.