Genomic diversity and genetic variation of Leishmania panamensis within its endemic range

Species belonging to the Leishmania (Viannia) subgenus are important causative agents of cutaneous and mucocutaneous leishmaniasis in Central and South America. These parasites possess several distinctive biological features that are influenced by their genetics, population structure, and genome instability. To date, several studies have revealed varying degrees of genetic diversity within Leishmania species. Particularly, in species of the L. (Viannia) subgenus, a generalized high intraspecific genetic diversity has been reported, although, conflicting conclusions have been drawn using different molecular techniques. Despite being the most common Leishmania species circulating in Panama and Colombia, few studies have analyzed clinical samples of Leishmania panamensis using whole-genome sequencing, and their restricted number of samples has limited the information they can provide to understand the population structure of L. panamensis. Here, we used next generation sequencing (NGS) to explore the genetic diversity of L. panamensis within its endemic range, analyzing data from 43 isolates of Colombian and Panamanian origin. Our results show the occurrence of three well-defined geographically correlated groups, and suggests the possible occurrence of additional phylogeographic groups. Furthermore, these results support the existence of a mixed mode of reproduction in L. panamensis, with varying frequencies of events of genetic recombination occurring primarily within subpopulations of closely related strains. This study offers important insights into the population genetics and reproduction mode of L. panamensis, paving the way to better understand their population structure and the emergence and maintenance of key eco-epidemiological traits.

Antagonistic effects of native strains of the soil fungus Paecilomyces against gastrointestinal nematode and protozoan parasites of pigs in Panama

A variety of gastrointestinal parasites naturally infect domestic pigs in Panama which may also occur as zoonotic infections in humans. Anthelmintic drug treatment, including mass drug administration, can lead to drug resistance, reflecting a need for alternatives. The objectives of this exploratory and observational study were: (1) to isolate and cultivate natives species of Paecilomyces from natural soils in Panama, and (2) to evaluate isolated strains for their capacity to parasitize endemic gastrointestinal nematode and protozoan parasites recovered from naturally infected domestic pigs by observing cultures for spore adhesion and hyphae penetration phases. Using microcultivation and inoculation techniques, four strains of Paecilomyces were isolated from three locations in Panama, out of which three successfully adhered to and penetrated free-living stages (eggs, cysts and oocysts) of Balantidium suis, coccidia, Trichuris suis and hookworm. To our knowledge, this is the first published report of a nematophagous fungus such as Paecilomyces successfully infecting this range of gastrointestinal parasites, particularly protozoan parasites.

Free-running cardiac magnetic resonance fingerprinting: Joint T1/T2 map and Cine imaging

PURPOSE

To develop and evaluate a novel non-ECG triggered 2D magnetic resonance fingerprinting (MRF) sequence allowing for simultaneous myocardial T₁ and T₂ mapping and cardiac Cine imaging.

METHODS

Cardiac MRF (cMRF) has been recently proposed to provide joint T₁/T₂ myocardial mapping by triggering the acquisition to mid-diastole and relying on a subject-dependent dictionary of MR signal evolutions to generate the maps. In this work, we propose a novel "free-running" (non-ECG triggered) cMRF framework for simultaneous myocardial T₁ and T₂ mapping and cardiac Cine imaging in a single scan. Free-running cMRF is based on a transient state bSSFP acquisition with tiny golden angle radial readouts, varying flip angle and multiple adiabatic inversion pulses. The acquired data is retrospectively gated into several cardiac phases, which are reconstructed with an approach that combines parallel imaging, low rank modelling and patch-based high-order tensor regularization. Free-running cMRF was evaluated in a standardized phantom and ten healthy subjects. Comparison with reference spin-echo, MOLLI, SASHA, T₂-GRASE and Cine was performed.

RESULTS

T₁ and T₂ values obtained with the proposed approach were in good agreement with reference phantom values (ICC(A,1) > 0.99). Reported values for myocardium septum T₁ were 1043 ± 48 ms, 1150 ± 100 ms and 1160 ± 79 ms for MOLLI, SASHA and free-running cMRF respectively and for T₂ of 51.7 ± 4.1 ms and 44.6 ± 4.1 ms for T₂-GRASE and free-running cMRF respectively. Good agreement was observed between free-running cMRF and conventional Cine 2D ejection fraction (bias = -0.83%).

CONCLUSION

The proposed free-running cardiac MRF approach allows for simultaneous assessment of myocardial T₁ and T₂ and Cine imaging in a single scan.

Cardiac Magnetic Resonance Fingerprinting: Technical Developments and Initial Clinical Validation

PURPOSE OF REVIEW

Magnetic resonance imaging (MRI) has enabled non-invasive myocardial tissue characterization in a wide range of cardiovascular diseases by quantifying several tissue specific parameters such as T1, T2, and T2* relaxation times. Simultaneous assessment of these parameters has recently gained interest to potentially improve diagnostic accuracy and enable further understanding of the underlying disease. However, these quantitative maps are usually acquired sequentially and are not necessarily co-registered, making multi-parametric analysis challenging. Magnetic resonance fingerprinting (MRF) has been recently introduced to unify and streamline parametric mapping into a single simultaneous, multi-parametric, fully co-registered, and efficient scan. Feasibility of cardiac MRF has been demonstrated and initial clinical validation studies are ongoing. Provide an overview of the cardiac MRF framework, recent technical developments and initial undergoing clinical validation.

RECENT FINDINGS

Cardiac MRF has enabled the acquisition of co-registered T1 and T2 maps in a single, efficient scan. Initial results demonstrate feasibility of cardiac MRF in healthy subjects and small patient cohorts. Current in vivo results show a small bias and comparable precision in T1 and T2 with respect to conventional clinical parametric mapping approaches. This bias may be explained by several confounding factors such as magnetization transfer and field inhomogeneities, which are currently not included in the cardiac MRF model. Initial clinical validation for cardiac MRF has demonstrated good reproducibility in healthy subjects and heart transplant patients, reduced artifacts in inflammatory cardiomyopathy patients and good differentiation between hypertrophic cardiomyopathy and healthy controls. Cardiac MRF has emerged as a novel technique for simultaneous, multi-parametric, and co-registered mapping of different tissue parameters. Initial efforts have focused on enabling T1, T2, and fat quantification; however this approach has the potential of enabling quantification of several other parameters (such as T2*, diffusion, perfusion, and flow) from a single scan. Initial results in healthy subjects and patients are promising, thus further clinical validation is now warranted.

Neonatal exposure to oestradiol increases dopaminergic transmission in nucleus accumbens and morphine-induced conditioned place preference in adult female rats

Steroid sex hormones produce physiological effects in reproductive tissues and also in nonreproductive tissues, such as the brain, particularly in cortical, limbic and midbrain areas. Dopamine (DA) neurones involved in processes such as prolactin secretion (tuberoinfundibular system), motor circuit regulation (nigrostriatal system) and driving of motivated behaviour (mesocorticolimbic system) are specially regulated by sex hormones. Indeed, sex hormones promote neurochemical and behavioural effects induced by drugs of abuse by tuning midbrain DA neurones in adult animals. However, the long-term effects induced by neonatal exposure to sex hormones on dopaminergic neurotransmission have not been fully studied. The present study aimed to determine whether a single neonatal exposure with oestradiol valerate (EV) results in a programming of dopaminergic neurotransmission in the nucleus accumbens (NAcc) of adult female rats. To answer this question, electrophysiological, neurochemical, cellular, molecular and behavioural techniques were used. The data show that frequency but not amplitude of the spontaneous excitatory postsynaptic current is significantly increased in NAcc medium spiny neurones of EV-treated rats. In addition, DA content and release are both increased in the NAcc of EV-treated rats, caused by an increased synthesis of this neurotransmitter. These results are functionally associated with a higher percentage of EV-treated rats conditioned to morphine, a drug of abuse, compared to controls. In conclusion, neonatal programming with oestradiol increases NAcc dopaminergic neurotransmission in adulthood, which may be associated with increased reinforcing effects of drugs of abuse.

Photochemistry of coronene in cosmic water ice analogs at different concentrations

This work presents the photochemistry of ultraviolet (UV) irradiated coronene in water ices at 15 K, studied using mid-infrared Fourier transform (FTIR) spectroscopy for C24H12:H2O at concentrations of (1:50), (1:150), (1:200), (1:300) and (1:400). Previous UV irradiation studies of anthracene:H2O, pyrene:H2O and benzo[ghi]perylene:H2O ices at 15 K have shown that aromatic alcohols and ketones, as well as CO2 and H2CO are formed at very low temperatures. Like-wise, here, in addition to the coronene cation, hydroxy-, keto-, and protonated coronene (coronene-H+) are formed. The rate constants for the decay of neutral coronene and for the formation of photoproducts have been derived. It is shown that PAHs and their UV-induced PAH:H2O photoproducts have mid-infrared spectroscopic signatures in the 5-8 μm region that can contribute to the interstellar ice components described by Boogert et al. (2008) as C1-C5. Our results suggest that oxygenated and hydrogenated PAHs could be in UV-irradiated regions of the ISM where water-rich ices are important.

Amphetamine treatment affects the extra-hypothalamic vasopressinergic system in a sex- and nucleus-dependent manner

The lateral septum (LS), a brain structure implicated in addictive behaviours, regulates the activation of dopaminergic neurones in the ventral tegmental area. Vasopressinergic projections from the extended amygdala to the LS, which are sexually dimorphic, could be responsible for the vulnerability to addiction in a sex-dependent manner. The present study aimed to investigate the modulatory effects of amphetamine (AMPH) on the expression of vasopressin (AVP) in the vasopressinergic extra-hypothalamic system in sensitised male and female rats. Adult male and female Sprague-Dawley rats underwent an AMPH-locomotor sensitisation protocol. Acute AMPH increased AVP mRNA expression in the medial amygdala (MeA), whereas AMPH-induced sensitisation increased AVP mRNA expression in the bed nucleus of the stria terminalis (BNST) only in females. Interestingly, the increase in AVP expression in BNST was higher in oestrus females compared to dioestrus females and acute AMPH resulted in a decrease in AVP levels in the LS, only in males. Thus, there are complex and region-specific interactions between AMPH and the extra-hypothalamic vasopressinergic system in the brain, underlying possible alterations in different behaviours caused by acute and chronic AMPH exposure.

Free breathing whole-heart 3D CINE MRI with self-gated Cartesian trajectory

Purpose

To present a method that uses a novel free-running self-gated acquisition to achieve isotropic resolution in whole heart 3D Cartesian cardiac CINE MRI.

Material and methods

3D cardiac CINE MRI using navigator gating results in long acquisition times. Recently, several frameworks based on self-gated non-Cartesian trajectories have been proposed to accelerate this acquisition. However, non-Cartesian reconstructions are computationally expensive due to gridding, particularly in 3D. In this work, we propose a novel highly efficient self-gated Cartesian approach for 3D cardiac CINE MRI. Acquisition is performed using CArtesian trajectory with Spiral PRofile ordering and Tiny golden angle step for eddy current reduction (so called here CASPR-Tiger). Data is acquired continuously under free breathing (retrospective ECG gating, no preparation pulses interruption) for 4–5 min and 4D whole-heart volumes (3D + cardiac phases) with isotropic spatial resolution are reconstructed from all available data using a soft gating technique combined with temporal total variation (TV) constrained iterative SENSE reconstruction.

Results

For data acquired on eight healthy subjects and three patients, the reconstructed images using the proposed method had good contrast and spatio-temporal variations, correctly recovering diastolic and systolic cardiac phases. Non-significant differences (P > 0.05) were observed in cardiac functional measurements obtained with proposed 3D approach and gold standard 2D multi-slice breath-hold acquisition.

Conclusion

The proposed approach enables isotropic 3D whole heart Cartesian cardiac CINE MRI in 4 to 5 min free breathing acquisition.

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A novel self-gated 3D Cartesian acquisition is proposed for free breathing whole-heart cardiac MRI

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The proposed framework has efficient k-space sampling, better eddy current performance and high computational efficiency

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The Proposed method is able to achieve high spatio-temporal resolution 3D cardiac CINE

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The proposed method only requires four to five minute free breathing scan

Ascariasis as cause of intestinal occlusion and concurrent appendicitis

Intestinal occlusion by ascariasis is a commonly seen socio-economic status low, is associated with poor sanitary hygiene. It is rare to see a case with both intestinal occlusion and appendicitis at the same time, as described in this report.

Kisspeptin is involved in ovarian follicular development during aging in rats

We have previously reported that kisspeptin (KP) may be under the control of the sympathetic innervation of the ovary. Considering that the sympathetic activity of the ovary increases with aging, it is possible that ovarian KP also increases during this period and participates in follicular development. To evaluate this possibility, we determined ovarian KP expression and its action on follicular development during reproductive aging in rats. We measured ovarian KP mRNA and protein levels in 6-, 8-, 10- and 12-month-old rats. To evaluate follicular developmental changes, intraovarian administration of KP or its antagonist, peptide 234 (P234), was performed using a mini-osmotic pump, and to evaluate FSH receptor (FSHR) changes in the senescent ovary, we stimulated cultured ovaries with KP, P234 and isoproterenol (ISO). Our results shows that KP expression in the ovary was increased in 10- and 12-month-old rats compared with 6-month-old rats, and this increase in KP was strongly correlated with the increase in ovarian norepinephrine observed with aging. The administration of KP produced an increase in corpora lutea and type III follicles in 6- and 10-month-old rats, which was reversed by P234 administration at 10 months. In addition, KP decreased the number and size of antral follicles in 6- and 10-month-old rats, while P234 administration produced an increase in these structures at the same ages. In ovarian cultures KP prevented the induction of FSHR by ISO. These results suggest that intraovarian KP negatively participates in the acquisition of FSHR, indicating a local role in the regulation of follicular development and ovulation during reproductive aging.

Neonatal exposure to estradiol valerate increases dopamine content in nigrostriatal pathway during adulthood in the rat

Research in programming has focused in the study of stimuli that affect sensitive periods of development such as prenatal and neonatal stage. We previously showed that exposure to estradiol valerate to female rats during the first 12 h of life increased catecholamine content in ventromedial-arcuatus hypothalamus of the adult rat. However, changes in others dopaminergic circuits have not been studied. The purpose of this work was to determine the neurotransmitters changes induced by neonatal estradiol valerate (0.1 mg/50 μl s. c. per rat) administration on nigrostriatal pathway of adult female rats. Sesame oil (50 μl s. c. per rat) was administered in a control parallel group. EV-1 adult rats presented effective markers of long-term estrogenization as decreased serum levels of progesterone and a reduction in the size of estrogen-sensitive organs. In the brain, neonatal estradiol valerate administration led to a significant increase in dopamine content in striatum, substantia nigra and ventral tegmental area. With respect to the contents of dopamine metabolites, only 3-methoxytyramine content increased in substantia nigra and ventral tegmental area. In addition, the content of noradrenaline increased only in striatum. Interestingly, estrogenized rats lacked locomotor activity induced by acute dose of amphetamine (1 mg/kg i. p.). Altogether, these results show that neonatal exposure to estradiol valerate permanently modified the content of monoamine neurotransmitters in nigrostriatal pathway and amphetamine-induced locomotor activity of adult female rats. This might imply that estrogenized rats could have changes in the expression of key proteins in dopaminergic regulation, as tyrosine hydroxylase and dopamine transporter.

Adverse events related to gastrointestinal endoscopic procedures in pediatric patients under anesthesia care and a predictive risk model (AEGEP Study)

BACKGROUND

Multiple studies have analyzed perioperative factors related to adverse events (AEs) in children who require gastrointestinal endoscopic procedures (GEP) in settings where deep sedation is the preferred anesthetic technique over general anesthesia (GA) but not for the opposite case.

METHODS

We reviewed our anesthesia institutional database, seeking children less than 12 years who underwent GEP over a 5-year period. A logistic regression was used to determine significant associations between preoperative conditions, characteristics of the procedure, airway management, anesthetic approaches and the presence of serious and non-serious AEs.

RESULTS

GA was preferred over deep sedation [77.8% vs. 22.2% in 2178 GEP under anesthesia care (n=1742)]. We found 96 AEs reported in 77 patients, including hypoxemia (1.82%), bronchospasm (1.14%) and laryngospasm (0.91%) as the most frequent. There were 2 cases of severe bradycardia related to laryngospasm/hypoxemia and a case of aspiration resulting in unplanned hospitalization, but there were no cases of intra- or postoperative deaths. Final predictive model for perioperative AEs included age <1 year, upper respiratory tract infections (URTI) <1 week prior to the procedure and low weight for the age (LWA) as independent risk factors and ventilation by facial mask as a protector against these events (p<0.05).

CONCLUSIONS

AEs are infrequent and severe ones are remote in a setting where AG is preferred over deep sedation. Ventilatory AEs are the most frequent and depend on biometrical and comorbid conditions more than anesthetic drugs chosen. Age <1 year, history of URTI in the week prior to the procedure and LWA work as independent risk factors for AEs in these patients.

Destrucción del tendón bicipital en el codo por bursitis bicipitorradial reumatoide

La artritis reumatoide es una enfermedad inflamatoria sistémica crónica de origen desconocido que afecta preferentemente a las membranas sinoviales de las articulaciones, tendones y bursas, y tiene numerosas manifestaciones intra y extraarticulares. De estas últimas las más frecuentes son los nódulos reumatoides y las bursitis.

Describimos el caso de una paciente con una bursitis bicipital reumatoide de tan larga data y ausencia de síntomas que acabó con una lisis del tendón distal del biceps brachii.

[Animal model for training in laparoscopic pyeloplasty]

OBJECTIVE

With the coming of the laparoscopy, multiple surgical techniques have been developed that have revolutionized the urological practice. The laparoscopic pyeloplasty has been one of the techniques most developed. However, there are very few training models that permit the surgeon to decrease the learning curve. An animal model of training for the laparoscopic pyeloplasty technique is described.

METHODS

Eight procedures of laparoscopic pyeloplasty were performed using the animal model (Gallus gallus) in the laparoscopic practice laboratory of the Urology Service of the University Hospital of Caracas. The preparation times of the model and the operation times of each surgeon were compared. The statistical analysis was made calculating the mean operation time, standard deviation, frequencies and percentages. A significant value was considered as p < 0.05.

RESULTS

The laparoscopic pyeloplasty procedure was performed successfully in all of the cases by two surgeons. The preparation time ranged from a maximum of 14 minutes to a minimum of 6 minutes, this being the same for both surgeons in the fourth case. The operation time ranged from a maximum of 65 minutes to a minimum of 43 minutes, observing significant differences when comparing the times individually for each surgeon. Only one case had filtration when comparing the patency of the specimen.

CONCLUSIONS

The animal model of training of laparoscopic pyeloplasty that is described is economical, reproducible, of easy availability and it makes it possible to develop laparoscopic surgical skills and competency necessary for reconstructive surgery and techniques that warrant intracorporeal suture.

Effect of temperature on free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A concentration

OBJECTIVE

To examine the effect of the duration of storage of serum and whole blood at different controlled temperatures on the concentrations of both serum free-beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in first-trimester screening for aneuploidies.

METHODS

The concentrations of free beta-hCG and PAPP-A were measured in samples collected from 10 pregnant women and stored as whole blood or serum for 1-8 days at 4, 20 or 40 degrees C. The concentrations measured were adjusted to take day-to-day variations into account and were expressed as a percentage of the values on day 0. In a second study involving 10 pregnant women, free beta-hCG was measured at 10 min and at 2, 4, 8 and 12 h after collection and storage at 30 or 40 degrees C, either as separated serum or as whole blood.

RESULTS

The change in the levels of PAPP-A in the separated serum at all three temperatures and in whole blood at 4 degrees C was always less than 10% throughout the 8 days of storage. In whole blood stored at 20 and 40 degrees C, the percentage variation was less than 10% only if the storage period was shorter than 4 days. The concentration of free beta-hCG was not altered by storage of either whole blood or separated serum at 4 degrees C throughout the 8 days of storage. At 20 degrees C, reliable results were obtained only if the maximum storage time was 2 days for separated serum and 1 day for whole blood. At 30 degrees C, reliable results were obtained only if the samples were analyzed within 2 h of collection, and at 40 degrees C the concentrations increased by more than 50% within 2 h and by about 500% after 1 day of storage.

CONCLUSION

In first-trimester screening for aneuploidies, analysis of blood samples should be undertaken within a few minutes of collection, otherwise the samples should be refrigerated at 4 degrees C throughout the interval between collection and analysis.

Intersectoral coordination, community empowerment and dengue prevention: six years of controlled interventions in Playa Municipality, Havana, Cuba

OBJECTIVE

To document the process, outcome and effectiveness of a community-based intervention for dengue control.

METHODS

The primary intervention, focused on strengthening intersectoral coordination, was initiated by researchers in January 2000 in a pilot area in Playa municipality, Havana. In August 2002 health authorities extended the intervention to neighbouring areas, one of which was selected for evaluation. In August 2003 a complementary strategy, focused on community empowerment, was initiated in half of the pilot area. In our control area, routine dengue activities continued throughout the study period. Longitudinal process assessment was carried out using document analysis, interviews and group discussions. Random population surveys in 1999, 2002 and 2005 assessed levels of participation and behavioural changes. Entomological surveillance data from 1999 to 2005 were used to determine effectiveness.

RESULTS

Mean scores for participation in the pilot area were 1.6, 3.4 and 4.4 at baseline, and 2 years after initiating intersectoral coordination and intersectoral coordination plus community empowerment interventions, respectively. While in the control area little behavioural change was observed over time, changes were considerable in the pilot and extension areas, with 80% of households involved in the community empowerment intervention showed adequate behavioural patterns. The pilot and extension areas attained comparable entomological effectiveness with significantly lower Breteau indices (BIs) than the control area. The pilot (sub-) area with the community empowerment intervention reached BIs below 0.1 that continued to be significantly lower than the one in the control area until the end of the study.

CONCLUSION

The study showed a trend in the levels and quality of participation, behavioural change and effectiveness of Aedes control from the routine activities only over an intervention with intersectoral coordination to one that combined intersectoral coordination and community empowerment approach.

Intersectoral coordination in Aedes aegypti control. A pilot project in Havana City, Cuba

Background The 55th World Health Assembly declared dengue prevention and control a priority and urged Member States to develop sustainable intersectoral strategies to this end. To provide evidence for the reorientation of the dengue prevention policy in Cuba, we launched an intervention study to document the effectiveness of a local-level intersectoral approach.

METHODS

We used a quasi-experimental design. Social scientists introduced participatory methods to facilitate dialogue in the biweekly meetings of the intersectoral Health Council of the intervention area. This council subsequently developed an intersectoral plan for dengue prevention, of which the core objective was to design and implement activities for communication and social mobilization. In the control area, routine dengue control activities continued without additional input. Knowledge, attitudes and perceptions of dengue, and entomological indices were compared inside and between the areas before and after the 1-year intervention period.

RESULTS

In the intervention area the Health Council elaborated an intersectoral plan for dengue prevention focused on source reduction. The Aedes aegypti control methods consisted in eliminating useless containers in the houses and surroundings, covering tanks, and cleaning public and inhabited areas. It was implemented through communication and social mobilization. The Health Council in the control area occasionally discussed dengue issues but did not develop a coordinated action plan. Good knowledge about breeding sites and disease symptoms increased significantly (by 49.7% and 17.1% respectively) in the intervention area as well as the proportion of respondents eliminating containers in and around their houses (by 44%). No changes were observed in the control area. The House Index in the intervention area was 3.72% at baseline and decreased to 0.61% after 1 year. In the control area it remained stable throughout the study period (1.31% and 1.65% respectively).

CONCLUSION

The introduction of a participatory approach by social scientists promotes changes in intersectoral management. This facilitates social mobilization which, in its turn, leads to significant changes in knowledge, attitudes and dengue-related practices in the population and eventually to more effective control of Ae. aegypti.

Complement regulatory proteins are expressed at low levels in embryonic human, wild type and transgenic porcine neural tissue

Allotransplantation of human foetal neural tissue for neurodegenerative disorders has been shown to provide clinical benefit but is limited by a number of issues including donor supply. The use of porcine foetal tissue as an alternative source of cells is being investigated but xenotransplants survive poorly as a result of immunological rejection, which may involve complement. In this study we investigated the expression of the membrane-bound complement regulatory proteins--decay accelerating factor (DAF), membrane co-factor protein (MCP) and CD59 in embryonic neural tissue. Cells were derived from human foetuses, wild-type porcine foetuses and porcine foetuses transgenic for human complement regulatory proteins and analysed using flow cytometry and immunocytochemistry. Functional assessment of human complement regulatory protein expression in transgenic porcine tissue was assessed by C3b deposition and cell survival on exposure to human complement. Human and wild-type porcine foetal neural tissue expressed moderate levels of MCP and CD59 but low or no levels of DAF. Neural tissue from porcine foetuses transgenic for human MCP (E174) expressed the transgene but failed to significantly inhibit human C3b deposition compared with non-transgenic tissue. In contrast, foetal neural tissue from two different human DAF transgenic pig lines (A74 and E71) known to express high levels of human DAF on endothelial cells, failed to express significant levels of human DAF in foetal neural tissue. Complement regulatory proteins such as MCP and CD59 are expressed in the human and wild-type embryonic brain but in contrast, DAF is expressed at very low levels. Pigs transgenic for human DAF express very low levels of human DAF on embryonic neural tissue. In pigs transgenic for human MCP, the transgene is expressed at similar levels to that in human embryonic neural tissue but at an insufficient level to prevent activation of the complement cascade. Thus alternative approaches to reducing complement activation by xenografted neural foetal tissue will be required if this process proves to be important in the rejection process.

Alpha Gal is widely expressed in embryonic porcine stem cells and neural tissue

Fetal porcine neural xenografts are an alternative to human fetal tissue for cell based treatments of a number of neurodegenerative conditions but are currently limited by host immunological rejection. The expression of a major immunological epitope, Galalpha1-3Galbeta1-4GlcNAcbeta-R (alphaGal) was determined on stem cells and primary cells derived from E26 porcine fetal brains. alphaGal was detected on the majority of neural stem cells and cells from primary cell suspensions. The expression of this epitope paralleled the binding of human IgG and IgM to the cells, a binding that was significantly reduced with anti-alphaGal depleted human serum. This study demonstrates that alphaGal expression is extensive in embryonic porcine neural cells and will be of relevance to any clinical trials using this tissue.

Mode of adsorption and orientation of an extracellular matrix protein affect its cell-adhesion-promoting activity

Cell adhesion to extracellular matrix contributes to the organization of tissues and modulates cell behavior. In conventional cell adhesion assays, plastic wells are coated with matrix proteins and assayed for their adhesion-promoting activity. We show here that factors such as sample composition, coating buffers, and manufacturers' plastic treatment markedly affect cell adhesion to the extracellular matrix protein laminin-5 (Ln-5). These factors were shown to affect adsorption efficiency as determined by measuring total adsorbed protein with a polyclonal anti-Ln-5 antiserum. They also influence the availability of the epitope for an adhesion-blocking anti-Ln-5 monoclonal antibody, suggesting that coating conditions affect the orientation of Ln-5. Generally, cell adhesion correlates more strongly with the availability of the epitope for the adhesion-blocking antibody than with total adsorbed Ln-5. Our data further indicate that cell adhesion to other matrix proteins may be influenced by similar factors. Adding Ln-5 samples to plastic wells that had been precoated with non-adhesion-blocking anti-Ln-5 antibodies made cell adhesion independent of factors such as sample composition, coating buffers, and source of plastic. Thus, the control of adsorption efficiency and orientation of extracellular matrix proteins is essential for creation of reliable and reproducible conditions in cell adhesion assays.

Influence of the SstI polymorphism at the apolipoprotein C-III gene locus on the plasma low-density-lipoprotein-cholesterol response to dietary monounsaturated fat

The plasma lipid response to changes in dietary fat and cholesterol can vary between individuals. The SstI polymorphism, arising from a cytosine to guanosine substitution in the 3' untranslated region of the APOC3 gene distinguishes between two alleles--S1 and S2. The S2 allele has been associated with elevated plasma triacylglycerol, cholesterol, and apolipoprotein (apo) C-III concentrations. In 90 young men we examined the effect of the same mutation on the response of low-density-lipoprotein (LDL) cholesterol to dietary monounsaturated fat. The frequency for the S2 allele was 0.14. Subjects were fed a low-fat diet for 25 d, followed by a diet rich in monounsaturated fatty acid (22% MUFA, 38% total fat) for 28 d; lipoproteins were measured at the end of each diet. There were no significant differences in initial total cholesterol between subjects with the APOC3*S1/APOC3*S1 (S1/S1) and APOC3*S1/APOC3*S2 (S1/S2) genotypes. After consumption of the diet high in MUFA, significant increases in LDL cholesterol (0.13 mmol/L, P < 0.027) were noted in the S1/S1 subjects whereas a significant decrease was observed in the S1/S2 subjects (-0.18 mmol/L, P < 0.046). Significant genotypic effects were seen for diet-induced changes in LDL cholesterol (P < 0.00034), total cholesterol (P < 0.009), and apo B (P < 0.0014). A study of the effect of the interaction between this mutation with that present in position -76 of the APOA1 gene promoter region (G/A) revealed that both mutations had an additive effect on changes in total cholesterol, LDL cholesterol, and apo B induced by diets. Plasma LDL-cholesterol responsiveness to the diet may be explained, at least in part, by variation at the APOC3 gene locus.

Affinity maturation of the BR96 anti-carcinoma antibody by codon-based mutagenesis

We have increased up to 65-fold the avidity of BR96, a mAb recognizing Lewis Y (Le(y))-related Ags expressed on the surface of many human carcinomas. Libraries of mutations in the complementarity-determining regions (CDRs) of BR96 were constructed in an M13 phage Fab expression vector by codon-based mutagenesis, a method that efficiently introduces large numbers and potentially all combinations of amino acid substitutions. Two mutants that improved the affinity of BR96 to tumor Ag were identified by screening the libraries on carcinoma cell lines. One mutant, M1, at position 97 (Asp to Ala) in CDR3 of the heavy chain, resulted in an 8- to 10-fold improvement in Ag binding, as assessed by ELISA. A second mutant, M2, at position 53 (Gly to Asp) in CDR2 of VH increased binding three- to fivefold. When these mutations were combined, the resulting Fab M3 was improved approximately 30-fold. An additional library was constructed in CDR1 of M1. M4, a mutation with three amino acid substitutions in CDR1, was isolated by screening the library with an enzyme conjugate of synthetic Le(y) tetrasaccharide (sLe(y)). This mutant improved BR96 Fab affinity to sLe(y) an estimated 15- to 20-fold by ELISA, and 14-fold as measured by surface plasmon resonance. The M4 IgG had 65-fold improved avidity to sLe(y) relative to the BR96 IgG. The mutants will be useful for comparison of the efficacy of Abs with different affinities for delivery of cytotoxic agents to tumor cells.

Affinity maturation of the BR96 anti-carcinoma antibody by codon-based mutagenesis

We have increased up to 65-fold the avidity of BR96, a mAb recognizing Lewis Y (Le(y))-related Ags expressed on the surface of many human carcinomas. Libraries of mutations in the complementarity-determining regions (CDRs) of BR96 were constructed in an M13 phage Fab expression vector by codon-based mutagenesis, a method that efficiently introduces large numbers and potentially all combinations of amino acid substitutions. Two mutants that improved the affinity of BR96 to tumor Ag were identified by screening the libraries on carcinoma cell lines. One mutant, M1, at position 97 (Asp to Ala) in CDR3 of the heavy chain, resulted in an 8- to 10-fold improvement in Ag binding, as assessed by ELISA. A second mutant, M2, at position 53 (Gly to Asp) in CDR2 of VH increased binding three- to fivefold. When these mutations were combined, the resulting Fab M3 was improved approximately 30-fold. An additional library was constructed in CDR1 of M1. M4, a mutation with three amino acid substitutions in CDR1, was isolated by screening the library with an enzyme conjugate of synthetic Le(y) tetrasaccharide (sLe(y)). This mutant improved BR96 Fab affinity to sLe(y) an estimated 15- to 20-fold by ELISA, and 14-fold as measured by surface plasmon resonance. The M4 IgG had 65-fold improved avidity to sLe(y) relative to the BR96 IgG. The mutants will be useful for comparison of the efficacy of Abs with different affinities for delivery of cytotoxic agents to tumor cells.

Electroencephalography in congenital malformations of the central nervous system

We studied clinical and EEG features of 36 cases with congenital malformations of the CNS. Patients were followed at the outpatient clinic of Hospital Cayetano Heredia and of Hogar Clinica San Juan de Dios in Lima-Peru, from January 1984 to June 1992. Eighty percent of the patients had convulsive syndromes and mental retardation. The most frequent malformation was agenesis of corpus callosum, and it was not possible to find a "typical" EEG pattern. The second were porencephalic cysts, with a good clinical-EEG correlation. There were two typical cases of schizencephaly, one of hemimegalencephaly with good prognosis, and one of holoprosencephaly. The results are compared to those obtained for a series we previously reported. Data discussed take into account reports on the subject registered in the literature. It is concluded that EEG is an useful method to evaluate possible CNS malformations in developing countries.

[Epileptic encephalopathies in childhood]

We present the study of 23 pediatric cases with infantile epileptic encephalopathies at the ambulatory neuropediatric facility of the Hospital Base Cayetano Heredia and ambulatory neurologic facility of Hospital IPPS Guillermo Almenara (Lima, Perú) between January 1984 and October 1988 with 6 to 54 months follow-up. There was one patient with Ohtahara syndrome, 9 with West syndrome and 13 with Lennox-Gastaut syndrome. The clinical and electroencephalographic characteristics were reviewed and related with the outcome. Despite the general characteristics of Ohtahara syndrome our patient had a good prognosis; only two West evolve into Lennox-Gastaut and none of these was West. Although the common features in these syndrome include frequent and intractable seizures and grave prognosis most of our patients had a good control of seizures.

Genotypic dependency of spontaneous yawning frequency in the rat

By inbreeding we have obtained two sublines of Sprague-Dawley rats which differ significantly in spontaneous mean yawning frequency (MYF). In generation F21 of the high-yawning (HY) subline MYF was 21.5 yawns/h (y/h) in males and 1.95 y/h in females, at the age of 2 months. In the low-yawning (LY) subline, in generation F16 the MYF was 0.9 y/h in males and only 0.5 y/h in females. During the first 15 days there are no differences in yawning frequency between HY and LY rats. Thereafter yawning increases with age, more steeply in the HY subline. The results of reciprocal crosses between both sublines indicate that the LY character is partially dominant over the HY one.

Transperitoneal absorption of intralipid in rats: total serum fatty acids and triglyceride after absorption

Intralipid 20% was injected percutaneously into the peritoneum of 58 female rats. The rats were divided into seven groups (with an additional control group of 35 rats). To measure transperitoneal absorption, we determined the serum fatty acid and triglyceride concentrations at 3-hr intervals for 24 hr, and found a considerable increase in all of the levels measured, with a maximum at about 6 hr. The serum triglyceride levels never rose above a mean value of 200 mg/100 ml. A second and smaller rise was seen after 15 hr, declining again to the initial values. The relative proportions of the different fatty acids changed, but not drastically.