Observation of magnet-induced star-like radiation of a plasma created from cancer cells in a laser trap

We present a new phenomenon resulting from the interaction of magnetic beads with cancer cells in a laser trap formed on a slide containing a depression 16.5 mm in diameter and 0.78 mm of maximum depth. This phenomenon includes the apparent formation and expansion of a dark bubble that attracts and incinerates surrounding matter when it explodes, which leads to a plasma emitting intense radiation that has the appearance of a star on a microscopic scale. We have observed the star-like phenomenon for more than 4 years, and the intensity depends on the laser's power. Measuring the laser power of the dark bubble shows the entrapment of electromagnetic energy as it expands.

P-740 Social disparities in pregnancy awareness among individuals in the general U.S. population

Study question

What are socio-demographic and lifestyle characteristics of pregnant individuals who were aware versus those who were unaware of pregnancy status in the general U.S. population.

Summary answer

Women unaware of their pregnancy status were more likely to be Non-Hispanic Black, living below the poverty line, and unmarried.

What is known already

The early weeks of pregnancy are critical for fetal programming of organ systems and consequently long-term offspring health. Individuals who are unaware of pregnancy are at risk of poor nutrition, inadvertent environmental chemical exposures and risky behaviors/lifestyles that contribute to inadequate prenatal care. Lack of pregnancy awareness increases the risk of pregnancy complications and misses opportunities for early intervention.

Study design, size, duration

We included 842 individuals aged between 20 to 44 years who had a positive urine pregnancy test result at time of the cross-sectional National Health and Examination Survey (NHANES), 2003-2016 cycles.

Participants/materials, setting, methods

The urine pregnancy tests and reproductive health interviews were conducted concurrently in medical examination center. We defined participants with a positive urine pregnancy test result but who reported not being pregnant during the interview as being unaware of their pregnancy status. Information on demographic, socio-economic, and lifestyle characteristics were collected by questionnaires. We employed student t test and chi-square test to compare the characteristics between individuals who were aware vs. unaware of the pregnancy.

Main results and the role of chance

Among 842 pregnant individuals, 62 (7.36%) were unaware of their pregnancy status. The mean (SE) ages (years) were similar between individuals who were unaware vs. those aware of their pregnancy status (Unaware: 28.05 (0.96) vs. Aware: 28.48 (0.32)). Compared with aware individuals, a higher proportion of the unaware group were Non-Hispanic Black (Unaware: 36.31% vs. Aware: 13.06%; p < 0.001), living in poverty (Unaware: 30.03% vs. Aware: 18.95%; p = 0.09), and unmarried (Unaware: 68.12% vs. Aware: 30.45%; p < 0.001). No significant differences were found for education (College degree and above: Unaware: 60.73% vs. Aware: 67.73%; p = 0.33) and smoking behavior between the two groups (Current smoker: Unaware: 4.97% vs. Aware: 8.88%; p = 0.38).

Limitations, reasons for caution

The sample size of this study was relatively small. Findings may not be representative of population characteristics.

Wider implications of the findings

Our findings point to significant social disparities in pregnancy awareness and have important implications for clinical practice and early identification of high-risk pregnancies.

Trial registration number

not applicable

Restoration of antitumor immunity through anti-MICA antibodies elicited with a chimeric protein

Background

Natural killer and cytotoxic CD8⁺ T cells are major players during antitumor immunity. They express NKG2D, an activating receptor that promotes tumor elimination through recognition of the MHC class I chain-related proteins A and B (MICA and MICB). Both molecules are overexpressed on a great variety of tumors from different tissues, making them attractive targets for immunotherapy. However, tumors shed MICA and MICB, and the soluble forms of both (sMICA and sMICB) mediate tumor-immune escape. Some reports indicate that anti-MICA antibodies (Ab) can promote the restoration of antitumor immunity through the induction of direct antitumor effects (antibody-dependent cell-mediated cytotoxicity, ADCC) and scavenging of sMICA. Therefore, we reasoned that an active induction of anti-MICA Ab with an immunogenic protein might represent a novel therapeutic and prophylactic alternative to restore antitumor immunity.

Methods

We generated a highly immunogenic chimeric protein (BLS-MICA) consisting of human MICA fused to the lumazine synthase from Brucella spp (BLS) and used it to generate anti-MICA polyclonal Ab (pAb) and to investigate if these anti-MICA Ab can reinstate antitumor immunity in mice using two different mouse tumors engineered to express MICA. We also explored the underlying mechanisms of this expected therapeutic effect.

Results

Immunization with BLS-MICA and administration of anti-MICA pAb elicited by BLS-MICA significantly delayed the growth of MICA-expressing mouse tumors but not of control tumors. The therapeutic effect of immunization with BLS-MICA included scavenging of sMICA and the anti-MICA Ab-mediated ADCC, promoting heightened intratumoral M1/proinflammatory macrophage and antigen-experienced CD8⁺ T cell recruitment.

Conclusions

Immunization with the chimeric protein BLS-MICA constitutes a useful way to actively induce therapeutic anti-MICA pAb that resulted in a reprogramming of the antitumor immune response towards an antitumoral/proinflammatory phenotype. Hence, the BLS-MICA chimeric protein constitutes a novel antitumor vaccine of potential application in patients with MICA-expressing tumors.

Chronic deltoid ligament insufficiency repair with Internal Brace™ augmentation

BACKGROUND

Patients with chronic deltoid ligament insufficiency (CDLI) present a challenging situation. Although numerous procedures have been described, optimal treatment is still a matter of debate. While the treatment armamentarium ranges from simple ligament repair to complex reconstructions with or without realignment osteotomies, direct repair augmented with an Internal Brace™ device appears to be an attractive intermediate option. We investigated functional outcomes and complications in patients with CDLI operated on using Internal Brace™ augmentation.

METHODS

A prospective study was conducted. Patients were included if they presented medial ankle pain and/or giving way, exhibited asymmetric flexible hindfoot valgus, failed conservative treatment, and had a positive MRI evaluated by an independent radiologist. Patients with stage IV flatfoot deformity, neuropathy and/or inflammatory arthritis were excluded. CDLI was confirmed intraoperatively with the arthroscopic drive-through sign. Patients were evaluated preoperatively and postoperatively using FAAM, SF-36 and grade of satisfaction. Paired t-tests were used to assess FAAM and SF-36 scores variation.

RESULTS

Thirteen patients met inclusion criteria. No patient was lost to follow-up, with a mean follow-up time of 13.5 months (range 6-21). Preoperative FAAM and SF-36 scores improved from 58.7 to 75.3 and from 60.2 to 84.4 postoperatively, respectively (p<.01). Two implant failures were observed, with no apparent compromise of construct stability. No patient was re-operated.

CONCLUSIONS

Our results suggest that deltoid ligament repair with Internal Brace™ augmentation in patients with CDLI is a reliable option with good functional outcomes and high satisfaction grade in short term follow-up.

LEVEL OF EVIDENCE

Level IV.

A dietary intervention with functional foods reduces metabolic endotoxaemia and attenuates biochemical abnormalities by modifying faecal microbiota in people with type 2 diabetes

AIM

To study the effects of a functional food-based dietary intervention on faecal microbiota and biochemical parameters in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

This placebo-controlled, randomized, double-blind study included 81 patients with T2D divided into two 3-month treatment groups: one following a reduced-energy diet with a dietary portfolio (DP) comprising high-fibre, polyphenol-rich and vegetable-protein functional foods; the other taking a placebo (P). The primary outcome was the effect of the DP on faecal microbiota. Secondary endpoints were biochemical parameters, lipopolysaccharide, branched-chain amino acids, trimethylamine N-oxide, glycosylated haemoglobin (HbA_1c) and free fatty acids (FFAs).

RESULTS

Patients with T2D exhibited intestinal dysbiosis characterized by an increase in Prevotella copri. Dietary intervention with functional foods significantly modified faecal microbiota compared with P by increasing alpha diversity and modifying the abundance of specific bacteria, independently of antidiabetic drugs. There was a decrease in P. copri and increases in Faecalibacterium prausnitzii and Akkermansia muciniphila, two bacterial species known to have anti-inflammatory effects. The DP group also exhibited significant reductions in areas under the curve for glucose, total and LDL cholesterol, FFAs, HbA_1c (P< 0.05), triglycerides and CRP, and an increase in antioxidant activity (P< 0.01) vs. the P group.

CONCLUSION

Long-term adherence to a high-fibre, polyphenol-enriched and vegetable-protein-based diet provides benefits for the composition of faecal microbiota, and may offer potential therapies for improvement of glycaemic control, dyslipidaemia and inflammation.

Disruption of protein kinase A localization induces acrosomal exocytosis in capacitated mouse sperm

Protein kinase A (PKA) is a broad-spectrum Ser/Thr kinase involved in the regulation of several cellular activities. Thus, its precise activation relies on being localized at specific subcellular places known as discrete PKA signalosomes. A-Kinase anchoring proteins (AKAPs) form scaffolding assemblies that play a pivotal role in PKA regulation by restricting its activity to specific microdomains. Because one of the first signaling events observed during mammalian sperm capacitation is PKA activation, understanding how PKA activity is restricted in space and time is crucial to decipher the critical steps of sperm capacitation. Here, we demonstrate that the anchoring of PKA to AKAP is not only necessary but also actively regulated during sperm capacitation. However, we find that once capacitated, the release of PKA from AKAP promotes a sudden Ca²⁺ influx through the sperm-specific Ca²⁺ channel CatSper, starting a tail-to-head Ca²⁺ propagation that triggers the acrosome reaction. Three-dimensional super-resolution imaging confirmed a redistribution of PKA within the flagellar structure throughout the capacitation process, which depends on anchoring to AKAP. These results represent a new signaling event that involves CatSper Ca²⁺ channels in the acrosome reaction, sensitive to PKA stimulation upon release from AKAP.

Amino acid profiles of young adults differ by sex, body mass index and insulin resistance

BACKGROUND AND AIMS

An increase in plasma branched-chain amino acids is associated with a higher risk of developing type 2 diabetes and cardiovascular diseases. However, little is known about the basal plasma amino acid concentrations in young adults. Our aim was to determine the plasma amino acid profiles of young adults and to evaluate how these profiles were modified by sex, body mass index (BMI) and insulin resistance (IR).

METHODS AND RESULTS

We performed a transversal study with 608 Mexican young adults aged 19.9 ± 2.4 years who were applicants to the Universidad Autónoma de San Luis Potosí. The subjects underwent a physical examination and provided a clinical history and a blood sample for biochemical, hormonal and amino acid analyses. The women had higher levels of arginine, aspartate and serine and lower levels of α-aminoadipic acid, cysteine, isoleucine, leucine, methionine, proline, tryptophan, tyrosine, urea and valine than the men. The obese subjects had higher levels of alanine, aspartate, cysteine, ornithine, phenylalanine, proline and tyrosine and lower levels of glycine, ornithine and serine than the normal weight subjects. Subjects with IR (defined as HOMA > 2.5) had higher levels of arginine, alanine, aspartate, isoleucine, leucine, phenylalanine, proline, tyrosine, taurine and valine than the subjects without IR. Furthermore, we identified two main groups in the subjects with obesity and/or IR; one group was composed of amino acids that positively correlated with the clinical, biochemical and hormonal parameters, whereas the second group exhibited negative correlations.

CONCLUSION

This study demonstrates that young adults with obesity or IR have altered amino acid profiles characterized by an increase in alanine, aspartate, proline and tyrosine and a decrease in glycine.

Chronic Deltoid Ligament Insufficiency Repair with Internal Brace™ Augmentation

Category:

Ankle, Arthroscopy, Sports

Introduction/Purpose:

Patients with chronic deltoid ligament insufficiency (CDLI) present a challenging situation in foot and ankle surgery. Although numerous surgical procedures have been described, optimal treatment is still a matter of debate. While the treatment armamentarium ranges from simple ligament repair to complex deltoid reconstructions with or without realignment osteotomies, direct repair augmented with an Internal Brace™ (Arthrex, Inc., Naples FL, USA) device appears to be an attractive intermediate option. We investigated functional outcomes and complications in patients with CDLI operated on using Internal Brace™ augmentation.

Methods:

After IRB approval, a prospective study was conducted. Patients were included if they were older than 18 years, presented medial ankle pain and/or giving way, exhibited asymmetric flexible hindfoot valgus, failed conservative treatment, and had a positive MRI evaluated by an independent radiologist. Patients with less than six months of follow-up, stage IV flatfoot deformity, neuropathy and/or inflammatory arthritis were excluded from the study. CDLI diagnosis was confirmed intraoperatively with the arthroscopic ankle drive-through sign. Patients were evaluated preoperatively and postoperatively using foot and ankle ability measure (FAAM) score, 36-item short form survey (SF-36), and grade of satisfaction. Paired t-tests were used to assess the pre- and postoperative FAAM and SF-36 scores.

Results:

Eleven patients met inclusion criteria. Nine patients were male and two female, with a mean age of 32 (18-61). Six ankles were right and five left. 88% presented with medial ankle pain, 67% medial drawer, 88% asymmetric hindfoot valgus, and 44% multidirectional ankle instability. No patient was lost to follow-up, with a mean follow-up time of 13.5 months (6-21). Preoperative FAAM and SF-36 scores improved from 58.7 to 75.3 and from 60.2 to 84.4 postoperatively, respectively (p<0.05). Two implant failures were observed, with no apparent compromise of construct stability. No patient was re-operated.

Conclusion:

Our results suggest that deltoid ligament repair with Internal Brace™ augmentation in patients with CDLI is a reliable option with good functional outcomes and high satisfaction grade in short term follow-up.

[Control of cardiovascular risk factors among patients with diabetes with and without cardiovascular disease]

INTRODUCTION

There is evidence that cardiovascular goals are beneficial in diabetes.

OBJECTIVE

To determine the distribution of cardiovascular risk levels in patients with diabetes and the clinical interventions they have received.

DESIGN

Descriptive cross-sectional study.

SETTING

SERMAS (Madrid) 2010.

SUBJECTS

All patients with diabetes. (n=41,096).

MAIN MEASUREMENTS

Patients in primary or secondary prevention, metabolic and cardiovascular risk factors control, pharmacological and non-pharmacological interventions. Patient and professional variables.

RESULTS

Around one-fifth (21.5%) (95%CI: 21.1% -21.9%) in secondary prevention (very high cardiovascular risk). HbA1c was under control in 31% (95%CI: 30.1%-32%), with 49.9% (95%CI: 48.8%-50.9%) with BP under control, and 39.4% (95% CI: 38.4%-40.4%) with LDL controlled. Only 8.9% (95%CI: 8.3%-9.5%) had a well-controlled HdA1c, BP and LDL, and in 19.8% (95%CI: 19%-20.6%) none of these were under control. Of those with an uncontrolled BP, 23.6% (95% CI: 23.2%-24%) had antihypertensive drugs. There was better control in patients older than 70 years, and those who lived in an urban center, or a lower number of patients per day.

CONCLUSION

In diabetic patients with very high cardiovascular risk (secondary prevention), just half of them had good control of cardiovascular risk factors (BP and LDL). An association was found between better control and older than 70, urban center or lower number of patients per day. This suggests developing strategies to promote a comprehensive control of cardiovascular risk factors in diabetic patients in secondary prevention.

Ultraviolet-B radiation modifies the quantitative and qualitative profile of flavonoids and amino acids in grape berries

Grapevine cv. Tempranillo fruit-bearing cuttings were exposed to supplemental ultraviolet-B (UV-B) radiation under controlled conditions, in order to study its effect on grape traits, ripening, amino acids and flavonoid profile. The plants were exposed to two doses of UV-B biologically effective (5.98 and 9.66kJm(-2)d(-1)), applied either from fruit set to ripeness or from the onset of veraison to ripeness. A 0kJm(-2)d(-1) treatment was included as a control. UV-B did not significantly modify grape berry size, but increased the relative mass of berry skin. Time to reach ripeness was not affected by UV-B, which may explain the lack of changes in technological maturity. The concentration of must extractable anthocyanins, colour density and skin flavonols were enhanced by UV-B, especially in plants exposed from fruit set. The quantitative and qualitative profile of grape skin flavonols were modified by UV-B radiation. Monosubstituted flavonols relative abundance increased proportionally to the accumulated UV-B doses. Furthermore, trisubstituted forms, which where predominant in non-exposed berries, were less abundant as UV-B exposure increased. Although total free amino acid content remained unaffected by the treatments, the increased levels of gamma-aminobutyric acid (GABA), as well as the decrease in threonine, isoleucine, methionine, serine and glycine, revealed a potential influence of UV-B on the GABA-mediated signalling and amino acid metabolism. UV-B had an overall positive impact on grape berry composition.

Indirect application of near infrared light induces neuroprotection in a mouse model of parkinsonism - an abscopal neuroprotective effect

We have previously shown near infrared light (NIr), directed transcranially, mitigates the loss of dopaminergic cells in MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-treated mice, a model of parkinsonism. These findings complement others suggesting NIr treatment protects against damage from various insults. However one puzzling feature of NIr treatment is that unilateral exposure can lead to a bilateral healing response, suggesting NIr may have 'indirect' protective effects. We investigated whether remote NIr treatment is neuroprotective by administering different MPTP doses (50-, 75-, 100-mg/kg) to mice and treating with 670-nm light directed specifically at either the head or body. Our results show that, despite no direct irradiation of the damaged tissue, remote NIr treatment produces a significant rescue of tyrosine hydroxylase-positive cells in the substantia nigra pars compacta at the milder MPTP dose of 50-mg/kg (∼30% increase vs sham-treated MPTP mice, p<0.05). However this protection did not appear as robust as that achieved by direct irradiation of the head (∼50% increase vs sham-treated MPTP mice, p<0.001). There was no quantifiable protective effect of NIr at higher MPTP doses, irrespective of the delivery mode. Astrocyte and microglia cell numbers in substantia nigra pars compacta were not influenced by either mode of NIr treatment. In summary, the findings suggest that treatment of a remote tissue with NIr is sufficient to induce protection of the brain, reminiscent of the 'abscopal effect' sometimes observed in radiation treatment of metastatic cancer. This discovery has implications for the clinical translation of light-based therapies, providing an improved mode of delivery over transcranial irradiation.

Long-term safety and efficacy of eslicarbazepine acetate in patients with focal seizures: results of the 1-year ESLIBASE retrospective study

BACKGROUND

Eslicarbazepine acetate (ESL) is a new antiepileptic drug (AED) licensed as adjunctive therapy in adults with partial-onset or focal seizures.

OBJECTIVE

To evaluate in a clinical practice setting the long-term efficacy and safety of ESL in patients with focal seizures.

METHODS

ESLIBASE was a retrospective study that included all patients with focal seizures who started ESL between January 2010 and July 2012 at 12 hospitals. ESL was prescribed individually according to real-life practice. Efficacy and safety were evaluated over 1 year. Switching from carbamazepine (CBZ) and oxcarbazepine (OXC) was assessed.

RESULTS

Three hundred and twenty-seven patients were included; 78% of patients were taking ≥2 other AEDs at baseline. Most (87%) began ESL because of poor seizure control and 13% because of adverse events (AEs) with CBZ or OXC. After 1 year, 237 patients (72.4%) remained on ESL. At 3, 6 and 12 months, the responder rate was 46.3%, 57.9%, and 52.5%, and 21.0%, 28.0%, and 25.3% of patients were seizure free. The responder rate significantly increased when ESL was combined with a non-sodium channel-targeting drug (non-SC drug) (66.7%) versus an SC drug (47.7%; p<0.001). At 12 months, 40.7% of patients had ≥1 AE; AEs led to treatment discontinuation in 16.2%. Dizziness, nausea, and somnolence were the most common AEs. The tolerability profile improved in >50% of the patients who switched from CBZ or OXC to ESL because of AEs.

CONCLUSIONS

ESL was well tolerated and effective in a real-world setting over 1 year. Side-effect profile improved when OXC and CBZ recipients were switched to ESL.

Composition and sensory evaluation of lamb carcasses used for the traditional Mexican lamb dish, "barbacoa"

The objective of this study was to determine the differences in carcass characteristics and sensory attributes of "barbacoa" (a traditional Mexican lamb dish), both of imported (New Zealand) and domestic lambs in Mexico. A total of 28 carcasses from Pelibuey, Pelibuey×Suffolk and imported lambs were used. Carcass composition was determined by dissection of primal cuts from the left half of each carcass. The "barbacoa" from each ovine group was prepared separately in order to perform a consumer sensory evaluation for aroma, taste and tenderness. Results showed that imported lambs had larger carcasses, greater fatness and had better conformation than national lambs. There was no difference between groups in terms of lean tissue percentage (muscle+others) or in total carcass fat. The sensory attributes of the "barbacoa" did not differ among breeds. Pelibuey lambs (rustic, prolific and adaptable to the wide variety of Mexican climates) show competitive production performance in relation to specialized breeds.

Soy protein isoflavones differentially regulate liver X receptor isoforms to modulate lipid metabolism and cholesterol transport in the liver and intestine in mice

AIMS/HYPOTHESIS

Liver X receptor (LXR)α regulates the genes involved in cholesterol, fatty acid and glucose metabolism. Soy protein (SP) consumption reduces the hepatic accumulation of cholesterol and triacylglycerol, and improves insulin sensitivity. However, it is not known whether these effects are mediated via LXRα. We therefore investigated whether the consumption of SP regulates metabolic changes in cholesterol metabolism and insulin sensitivity via LXRα.

METHODS

Wild-type (WT) and Lxrα(-/-) (Lxrα, also known as Nr1h3) mice were fed an SP diet with or without cholesterol for 28 days. The expression of LXRα target genes was measured in liver and intestine, as were hepatic lipid content and faecal bile acid concentration. Oral glucose and insulin tolerance tests were also performed. Hepatocytes were used to study the effect of isoflavones on LXR activity.

RESULTS

The livers of WT and Lxrα(-/-) mice fed an SP high-cholesterol diet showed less steatosis than those fed casein. The SP diet increased the expression of the ATP-binding cassette (ABC) sub-family genes Abca1, Abcg5 and Abcg8 in the liver and intestine, as well as increasing total faecal bile acid excretion and insulin sensitivity in WT mice compared with mice fed a casein diet. However, these effects of SP were not observed in Lxrα(-/-) mice. The SP isoflavone, genistein, repressed the activation of LXRα target genes by T0901317, whereas it stimulated the activation of LXRβ target genes. The AMP-activated protein kinase inhibitor, compound C, had the opposite effects to those of genistein.

CONCLUSIONS/INTERPRETATION

Our results suggest that SP isoflavones stimulate the phosphorylation of LXRα or LXRβ, resulting in different biological effects for each LXR isoform.

Rationale for hypothalamus-deep brain stimulation in food intake disorders and obesity

Appetite modulation in conjunction with enhancing metabolic rate with hypothalamic lesions has been widely documented in animal and even in humans. It appears these effects can be reproduced by DBS, and the titratability and reversibility of this procedure, in addition to well established safety profile, make DBS an appealing option for obesity treatment. Targeting the hypothalamus with DBS has already been shown to be feasible and potentially effective in managing patients with intractable chronic cluster headache [26]. The surgical risk however must be cautiously taken into account when targeting the hypothalamus, where some mortality cases have been reported when targeting the posterior part [34]. The development of new surgical approach will probably reduce this surgical risk. Moreover, the role of functional neurosurgery in obesity is not a new idea. In fact, LH was targeted in obese humans with electrocoagulation more than 30 years ago, resulting in significant yet transient appetite suppression and slight weight reduction [36]. All those elements have made possible the recent regain of interest in DBS for morbid obesity and open an exciting new area of research in neurosurgery and endocrinology.

Gait is associated with an increase in tonic firing of the sub-cuneiform nucleus neurons

In animals, the pedunculopontine (PPN) and the sub-cuneiform (SCU) nuclei located in the upper brainstem are involved during the processing of gait. Similar functional nuclei are suspected in humans but their role in gait is unclear. Here we show that, using extra-cellular recordings of the PPN/SCU region obtained in two parkinsonian patients, the SCU neurons increased their firing rate without modifying their firing pattern during mimicked steps. We conclude that SCU neurons are activated during gait processes.

Interindividual glucocorticoid sensitivity in young healthy subjects: the role of glucocorticoid receptor alpha and beta isoforms ratio

Only few studies have addressed the interindividual variation and tissue specificity of glucocorticoid (GC) sensitivity in healthy individuals, a phenomenon observed in pathological conditions. Alternative splicing of the glucocorticoid receptor (GR) produces alpha and beta isoforms. GRbeta has dominant-negative effects on hormone-induced GRalpha effects, and an increased expression of the GRbeta has been associated with glucocorticoid resistance. We determined, using a simple, rapid, and accurate Real-Time PCR assay, the individual mRNAs expression of GRalpha and GRbeta in 26 normal subjects (mean+/-SE, age 30+/-6 years; 12 males and 14 females), in order to evaluate the role of these isoforms in glucocorticoid sensitivity in health. Glyceraldehydes-3-phosphate dehydrogenase (GAPDH) was used as a housekeeper gene. GRalpha/GAPDH, GRbeta/GAPDH and GRalpha/GRbeta ratios showed a normal distribution. We observed a higher expression of GRalpha compared to GRbeta and an interindividual variability in the GRalpha, GRbeta, and GAPDH gene expressions in the young healthy population. In addition, no correlation was observed between GRalpha/GRbeta ratio and the dexamethasone (DEX) doses needed to suppress plasma cortisol, GRalpha/GRbeta ratio and the concentration of DEX that caused inhibition of Con-A stimulated cell proliferation, and GRalpha/GRbeta ratio and the affinity of GR (Kd) of each subject. Therefore, the variability of GC sensitivity observed in normal subjects can not be ascribed to the variation in the GRalpha and GRbeta expression.

Phenotype and genotype correlation of the microconversion from the CYP21A1P to the CYP21A2 gene in congenital adrenal hyperplasia

Deficiency of 21-hydroxylase is the most common form of congenital adrenal hyperplasia (CAH-21OH). We determined by allele-specific PCR the frequency of microconversion in the CYP21A2 gene in 50 Brazilian patients with the classical (salt wasting: SW and simple virilizing: SV) forms and nonclassical (NC) form of CAH-21OH and correlated genotype with phenotype. Genotypes were classified into three mutation groups (A, B, and C) based on the amount of enzymatic activity in in vitro studies using adrenal cells. In 94 unrelated alleles, we diagnosed 76% of the affected alleles after screening for 7 microconversions. The most frequent point mutations observed in this series were I172N (19%), V281L (18%), and IVS2,A/C>G,-12 (15%). In the SW form, the most frequent mutation was IVS2,A/C>G,-12 (38%), in the SV form it was I172N (53%), and in the NC form it was V281L (57.7%). We observed a good correlation between genotype and phenotype. Discordance between genotype and phenotype was found in one SV patient with a mild mutation in one of the alleles (R356W/V281L). However, we cannot rule out the presence of an additional mutation in these alleles. We also observed a good correlation of genotype with 17alpha-hydroxyprogesterone, testosterone, and androstenedione levels. The severity of external genitalia virilization correlated with the severity of mutation. In conclusion, the frequencies described in the present study did not differ from worldwide studies, including the Brazilian population. The few differences observed may reflect individual sample variations. This new Brazilian cohort study suggests the presence of new mutations in Brazilian patients with different forms of CAH-21OH.

Characterization of enzootic foci of Venezuelan equine encephalitis virus in western Venezuela

The distribution of the sylvatic subtype ID Venezuelan equine encephalitis (VEE) viruses in the lowland tropical forests of western Venezuela was investigated using remote sensing and geographic information system technologies. Landsat 5 Thematic Mapper satellite imagery was used to study the reflectance patterns of VEE endemic foci and to identify other locations with similar reflectance patterns. Enzootic VEE virus variants isolated during this study are the closest genetic relatives of the epizootic viruses that emerged in western Venezuela during 1992-1993. VEE virus surveillance was conducted by exposing sentinel hamsters to mosquito bites and trapping wild vertebrates in seven forests identified and located by means of the satellite image. We isolated VEE viruses from 48 of a total of 1,363 sentinel hamsters in two of the forests on six occasions, in both dry and wet seasons. None of the 12 small vertebrates captured in 8,190 trap-nights showed signs of previous VEE virus infection. The satellite image was classified into 13 validated classes of land use/vegetation using unsupervised and supervised techniques. Data derived from the image consisted of the raw digital values of near- and mid-infrared bands 4, 5, and 7, derived Tasseled Cap indices of wetness, greenness, and brightness, and the Normalized Difference Vegetation Index. Digitized maps provided ancillary data of elevation and soil geomorphology. Image enhancement was applied using Principal Component Analysis. A digital layer of roads together with georeferenced images was used to locate the study sites. A cluster analysis using the above data revealed two main groups of dense forests separated by spectral properties, altitude, and soil geomorphology. Virus was isolated more frequently from the forest type identified on flat flood plains of main rivers rather than the forest type found on the rolling hills of the study area. The spatial analysis suggests that mosquitoes carrying the enzootic viruses would reach 82-97% of the total land area by flying only 1-3 km from forests. We hypothesize that humans within that area are at risk of severe disease caused by enzootic ID VEE viruses. By contrast, equines could actually become naturally vaccinated, thus preventing the local emergence of epizootic IC VEE virus strains and protecting humans indirectly.

Biochemical deficiency of pyridoxine does not affect interleukin-2 production of lymphocytes from patients with Sjögren's syndrome

BACKGROUND

There is evidence that pyridoxine deficiency may alter the immune response. It is not known whether a deficiency of this vitamin is evident in subjects with primary Sjögren's syndrome (SS).

OBJECTIVE

We studied whether subjects with primary SS showed a biochemical deficiency of pyridoxine, and if it is associated with abnormal production of interleukin-2 from lymphocytes stimulated in vitro with phytohemagglutinin (PHA).

DESIGN

Two studies were conducted, (i) biochemical and nutritional assessments were performed in a cross-over study in subjects with primary SS, who were supplemented with 25 mg/day of pyridoxine or placebo for 3 months. After 1 month washout, they were supplemented for 3 months with placebo, (ii) patients with SS and matched controls received pyridoxine or placebo for 45 days, and a blood sample was obtained to study IL-2 production and expression in T-lymphocytes stimulated with PHA.

RESULTS

Subjects with primary SS showed limited dietary intake of pyridoxine and biochemical deficiency of this vitamin assessed through the activation coefficient of the erythrocyte aspartate aminotransferase. The biochemical deficiency did not affect production nor mRNA expression of IL-2 from T-lymphocytes stimulated in vitro with PHA compared with the control group. Supplementation of subjects with primary SS with 25 mg/day with pyridoxine for 45 days did not produce any significant change as compared to those patients supplemented with placebo.

CONCLUSIONS

Subjects with primary SS showed biochemical deficiency of pyridoxine, possibly due to limited intake of this vitamin which was corrected by supplementation with pyridoxine. However, IL-2 production and mRNA expression from stimulated lymphocytes were unaffected by supplementation, probably because the deficiency was not severe enough to affect the immune system.

SPONSORSHIP

This work was supported by the National Council of Science and Technology (CONACYT), Mexico, grant no. 212226-5-0902PM.

Extramedullary hematopoiesis in hereditary spherocytosis deficient in ankyrin: a case report

Hereditary spherocytosis (HS) is a common inherited hemolytic anemia due to red cell membrane defects. Extramedullary hematopoiesis is a compensatory response to insufficient bone marrow blood cell production. The preferred sites of extramedullary hematopoietic involvement are the spleen, liver, and lymph nodes, but in HS the posterior paravertebral mediastinum is also commonly involved. A nonsplenectomized 74-year-old man with mild HS, with primary deficiency in ankyrin, was found by magnetic resonance imaging to have thoracic paravertebral hematopoietic masses. The patient showed high serum levels of erythropoietin, which may have played a role in the development of extramedullary hematopoietic masses through a continuous hematopoietic stimulus to erythroid cells in the propositus. The long-standing history of respiratory infections and of hypoxia in the propositus may have been an additional etiological factor.

Induction of expression of branched-chain aminotransferase and alpha-keto acid dehydrogenase in rat tissues during lactation

This study was designed to determine the effect of lactation and weaning on the gene expression of branched-chain aminotransaminase (BCAT) and branched-chain alpha-keto acid dehydrogenase (BCKD) in different tissues of the lactating rat. BCAT activity increased in mammary tissue during lactation and was 6-fold higher than in virgin rats. This increase was associated with an increase in protein levels measured by immunoblot analysis, and with an increase in BCAT mitochondrial (BCATm) mRNA concentration. Twenty-four hours after weaning, BCAT activity, protein concentration, and mRNA levels in the dam decreased. BCAT activity, protein enzyme levels, and BCATm mRNA concentration in muscle were higher in weaning rats than in lactating rats. BCAT cytosolic (BCATc) mRNA was not expressed in mammary tissue, and there was no BCATc enzyme detected by Western blot in any physiological state. Mammary tissue BCKD activity increased and was active (dephosphorylated) during the lactation period. The level of enzyme also increased and the mRNA level for the E2 subunit in mammary tissue was 10-fold higher than the virgin values. Hepatic enzyme activity increased during weaning, and this was associated with the protein level and with the mRNA level of the E2 subunit. Muscle BCKD activity and protein content were the lowest of all tissues, and the E2 subunit mRNA level was barely detected by Northern blot analysis. The results suggest gene regulation of the two main catabolic enzymes of the branched-chain amino acid metabolism during lactation.

Amino acid intake during lactation and amino acids of plasma and human milk

The aim of this study was to determine the free amino acid pool in plasma and milk in marginally nourished lactating women. Twenty-eight rural women (age, 23.9+/-5y; weight 50.2+/-4.9 kg; height, 148.2+/-4.8 cm) were studied under metabolic balance conditions. Subjects were divided into 6 groups (5-6 women in each), representing rural mothers postweaning and in the 15, 3rd, and 6th months of lactation; nonpregnant, nonlactating controls were from rural and urban areas. Amino acid analyses of diet and of plasma and milk samples were performed using a Beckman 6300 amino acid analyzer. Lysine intakes were lower than the recommended intake for lactating women (RDA). Plasma amino acid profiles differed between the lactating and weaned groups: aspartate and isoleucine increased at the 6th month (P < 0.05), while valine declined over weaning time (P < 0.05). In milk, valine and proline decreased at the 6th month (P < 0.05), while serine rose at the 3rd month. Free amino acid pools were 1- to 15-fold higher in plasma than in milk for branched-chain amino acids and basic, aromatic, and neutral amino acids. In mammary tissue these amino acids can be channeled to tissue and milk protein synthesis or to catabolic pathways. Glutamate was 40-fold higher in milk with respect to plasma content. This was the predominant amino acid in the free amino acid pool in milk. These results suggest selective amino acid transport in mammary tissue during lactation.

Ontogeny and subcellular localization of rat liver mitochondrial branched chain amino-acid aminotransferase

Branched chain amino-acid aminotransferase (BCAT) activity is present in fetal liver but the developmental pattern of mitochondrial BCAT (BCATm) expression in rat liver has not been studied. The aim of this study was to determine the activity, protein and mRNA concentration of BCATm in fetal and postnatal rat liver, and to localize this enzyme at the cellular and subcellular levels at both developmental stages. Maximal BCAT activity and BCATm mRNA expression occurred at 17 days' gestation in fetal rat liver and then declined significantly immediately after birth. This pattern was observed only in liver; rat heart showed a different developmental pattern. Fetal liver showed intense immunostaining to BCATm in the nuclei and mitochondria of hepatic cells and blood cell precursors; in contrast, adult liver showed mild immunoreactivity located only in the mitochondria of hepatocytes. BCAT activity in isolated fetal liver nuclei was 0.64 mU x mg(-1) protein whereas it was undetectable in adult liver nuclei. By Western blot analysis the BCATm antibody recognized a 41-kDa protein in fetal liver nuclei, and proteins of 41 and 43 kDa in fetal liver supernatant. In adult rat liver supernatant, the BCATm antibody recognized only a 43-kDa protein; however, neither protein was detected in adult rat liver nuclei. The appearance of the 41-kDa protein was associated with the presence of the highly active form of BCATm. These results suggest the existence of active and inactive forms of BCAT in rat liver.

[Homocysteine metabolism and risk of cardiovascular diseases: importance of the nutritional status on folic acid, vitamins B6 and B12]

Homocysteine is a thiol-containing amino acid derived from methionine metabolism that can be degraded through two enzymatic pathways: remethylation and trans-sulfuration. In remethylation, homocysteine regenerates methionine. In the trans-sulfuration pathway, homocysteine forms cysteine. Due to the rapid metabolic utilization, the plasma concentration of this amino acid is low. Homocysteine circulates as free thiol, homocystine, or bound to free cysteine or to cysteine residues of proteins. Genetic defects of some enzymes in the homocysteine metabolism, or nutritional deficiencies of folic acid, vitamin B6 and B12 lead to an increase in homocysteine plasma concentration and is associated to an increment in cardiovascular diseases. On the basis of clinical and epidemiological studies, homocysteine plasma concentration is considered to be an independent risk factor for the development of atherothrombotic and cardiovascular diseases. The present review describes the homocysteine metabolism, the epidemiological evidence showing the association between homocysteine and the incidence of cardiovascular diseases. The mechanisms by which homocysteine produces vascular damage are indicated. Finally, some recommendations are given for the nutritional therapy of patients with hyperhomocysteinemia.

Localization and expression of BCAT during pregnancy and lactation in the rat mammary gland

During lactation, branched-chain aminotransferase (BCAT) gene expression increases in the mammary gland. To determine the cell type and whether this induction is present only during lactation, female rats were randomly assigned to one of three experimental groups: pregnancy, lactation, or postweaning. Mammary gland BCAT activity during the first days of pregnancy was similar to that of virgin rats, increasing significantly from day 16 to the last day of pregnancy. Maximal BCAT activity occurred on day 12 of lactation. During postweaning, BCAT activity decreased rapidly to values close to those observed in virgin rats. Analyses by Western and Northern blot revealed that changes in enzyme activity were accompanied by parallel changes in the amount of enzyme and its mRNA. Immunohistochemical studies of the mammary gland showed a progressive increase in mitochondrial BCAT (mBCAT)-specific staining of the epithelial acinar cells during lactation, reaching high levels by day 12. Immunoreactivity decreased rapidly after weaning. There was a significant correlation between total BCAT activity and milk production. These results indicate that the pattern of mBCAT gene expression follows lactogenesis stages I and II and is restricted to the milk-producing epithelial acinar cells. Furthermore, BCAT activity is associated with milk production in the mammary gland during lactation.