Can we predict a "tsunami"? Symptomatic and syndromal density, mood instability and treatment intensity in people with bipolar disorders under a strict and long lockdown

BACKGROUND

Converging evidence supports the involvement of circadian rhythm disturbances in the course and morbidity of bipolar disorders (BD). During 2020, lockdown measures were introduced worldwide to contain the health crisis caused by the COVID-19 pandemic. As a result, chronobiological rhythms were critically disrupted and illness outcomes were expected to worsen. The current study aimed to explore changes in morbidity among BD patients living under lockdown.

METHODS

Ninety BD outpatients under naturalistic treatment conditions were followed from March to September 2020 using a mood chart technique. Different treatment and illness variables, including mood instability, were assessed and compared with the outcomes obtained during the same 28-week period in 2019.

RESULTS

For most clinical variables, no significant differences were observed between time periods. A slight decrease was found in symptom intensity (from 15.19 ± 20.62 to 10.34 ± 15.79, FDR-adjusted p = 0.04) and in the number of depressive episodes (from 0.39 ± 0.74 to 0.22 ± 0.63, FDR-adjusted p = 0.03), whereas the intensity of pharmacological treatment remained unchanged. Previous illness course predicted mood outcomes during the confinement.

LIMITATIONS

Follow-up periods were relatively short. Further, actigraphy or other methods capable of ensuring significant changes in physical activity were not used.

CONCLUSIONS

In line with other studies, our findings show no worsening in the clinical morbidity of BD patients during lockdown. This conspicuous contrast between our initial predictions and the observed findings highlights the fact that we are still far from being able to provide accurate predictive models for BD.

Reconfigurable frequency multipliers based on graphene field-effect transistors

Run-time device-level reconfigurability has the potential to boost the performance and functionality of numerous circuits beyond the limits imposed by the integration density. The key ingredient for the implementation of reconfigurable electronics lies in ambipolarity, which is easily accessible in a substantial number of two-dimensional materials, either by contact engineering or architecture device-level design. In this work, we showcase graphene as an optimal solution to implement high-frequency reconfigurable electronics. We propose and analyze a split-gate graphene field-effect transistor, demonstrating its capability to perform as a dynamically tunable frequency multiplier. The study is based on a physically based numerical simulator validated and tested against experiments. The proposed architecture is evaluated in terms of its performance as a tunable frequency multiplier, able to switch between doubler, tripler or quadrupler operation modes. Different material and device parameters are analyzed, and their impact is assessed in terms of the reconfigurable graphene frequency multiplier performance.

Are all antidepressants the same? The consumer has a point

BACKGROUND

Although a large variety of antidepressants agents (AD) with different mechanisms of action are available, no significant differences in efficacy and safety have been shown. However, there have been few attempts to incorporate data on subjective experiences under different AD.

METHOD

We conducted a qualitative and quantitative analysis of the posts from the website www.askapatient.com from different AD. We reviewed a random sample of 1000 posts.

RESULT

After applying the inclusion and exclusion criteria, we included a final sample of 450 posts, 50 on each of the most used AD: sertraline, citalopram, paroxetine, escitalopram, fluoxetine, venlafaxine, duloxetine, mirtazapine, and bupropion. Bupropion, citalopram, and venlafaxine had the higher overall satisfaction ratings. Sertraline, paroxetine, and fluoxetine had high reports of emotional blunting, while bupropion very few. Overall satisfaction with AD treatment was inversely associated with the presence of the following side-effects: suicidality, irritability, emotional blunting, cognitive disturbances, and withdrawal symptoms. After adjusting for confounders, only emotional blunting was shown to be more frequently reported by users of serotonergic agents, as compared to non-serotoninergic agents.

CONCLUSION

This research points out that the subjective experience of patients under treatment should be taken into consideration when selecting an AD as differences between agents were evident. In contrast to the more frequent treatment decisions, users might prefer receiving a non-serotoninergic agent over a serotonergic one due to their lower propensity to produce emotional blunting.

Graphene BioFET sensors for SARS-CoV-2 detection: a multiscale simulation approach

Biological Field-Effect Transistors (BioFETs) have already demonstrated enormous potential for detecting minute amounts of ions and molecules. The use of two-dimensional (2D) materials has been shown to boost their performance and to enable the design of new applications. This combination deserves special interest in the current pandemic caused by the SARS-CoV-2 virus which demands fast, reliable and cheap detection methods. However, in spite of the experimental advances, there is a lack of a comprehensive and in-depth computational approach to capture the mechanisms underlying the sensor behaviour. Here, we present a multiscale platform that combines detailed atomic models of the molecules with mesoscopic device-level simulations. The fine-level description exploited in this approach accounts for the charge distribution of the receptor, its reconfiguration when the target binds to it, and the consequences in terms of sensitivity on the transduction mechanism. The results encourage the further exploration of improved sensor designs and 2D materials combined with diverse receptors selected to achieve the desired specificity.

P-336 Progesterone receptor is not downregulated in the endometrial epithelial compartment of women without embryo implantation during frozen thawed embryo transfer cycles

Study question

Is the mean endometrial progesterone receptor (PGR) expression in the endometrial epithelial compartment different between women with and without embryo implantation failure?

Summary answer

PGR expression is higher in epithelial endometrial compartment of women with embryo implantation failure, during mock hormonal endometrial preparation preceding frozen thawed embryo transfer cycles.

What is known already

PGR downregulation is critical for embryo implantation. Downregulation takes place during the window of implantation in the EEC, while, in stromal cells, it is highly expressed. Embryos are unable to attach to the maternal surface when PGR expression remains expressed in epithelial endometrial compartment (EEC). Limited information is available whether PGR is downregulated during hormonal endometrial preparation for frozen thawed embryo transfer cycles.

Study design, size, duration

In this cohort study, 47 endometrial biopsies were obtained between 2016-2017

Participants/materials, setting, methods

Infertile women (n = 47) submitted to frozen thawed embryo transfer (FET) cycles had an endometrial biopsy after 5 days of intravaginal progesterone supplementation during mock hormonal endometrial preparation (HEP) preceding FET and prospectively followed until confirmation of an intrauterine pregnancy. PGR immunostaining was performed using standard immunohistochemical technique (clone BSB2 - BS2126, BIO SB). PRG expression was quantified using the histologic score (HScore, range from 0 - 4). Ethical approval was obtained from local ethical committee.

Main results and the role of chance

Age, body mass index, endometrial thickness, and the number of embryos transferred were not significantly different between women who became or not pregnant. PGR Hscore (mean ± SD) in EEC was significantly lower in pregnant women (1.2 ± 0.8; n = 14 ) compared to women without pregnancy (2.8 ± 0.6; n = 33 ) Student t-test p < 0.0001. The AUC was 0.90 ± 0.05 (95% CI: 0.7-1) p < 0.0001 displaying 94.2 % sensitivity and 80.4% specificity for a 1.65 PGR cut-off value.

Limitations, reasons for caution

This is an observational study to determine if a difference in PGR expression was identified in these cases

Wider implications of the findings

The mean PGR expression is abnormally higher in EEC of women with embryo implantation failure using HEP for FET cycles. The 1.65 cut-off may be used in future studies to investigate whether high PGR expression is a risk factor for failure of blastocyst implantation in HEP for FET.

Trial registration number

not applicable

A DNA Extraction Method for Insects From Sticky Traps: Targeting a Low Abundance Pest, Phthorimaea absoluta (Lepidoptera: Gelechiidae), in Mixed Species Communities

Invasive insects can cause catastrophic damage to ecosystems and cost billions of dollars each year due to management expenses and lost revenue. Rapid detection is an important step to prevent invasive insects from spreading, but improvements in detection capabilities are needed for bulk collections like those from sticky traps. Here we present a bulk DNA extraction method designed for the detection of Phthorimaea absoluta Meyrick (Lepidoptera: Gelechiidae), an invasive moth that can decimate tomato crops. We test the extraction method for insect specimens on sticky traps, subjected to different temperature and humidity conditions, and among mock insect communities left in the field for up to 21 d. We find that the extraction method yielded high success (>92%) in recovering target DNA across field and lab trials, without a decline in recovery after three weeks, across all treatments. These results may have a large impact on tomato growing regions where P. absoluta is in the early stages of invasion or not yet present. The extraction method can also be used to improve detection capabilities for other bulk insect collections, especially those using sticky traps, to the benefit of pest surveys and biodiversity studies.

Multi-scale modeling of 2D GaSe FETs with strained channels

Electronic devices based on bidimensional materials (2DMs) are the subject of an intense experimental research, that demands a tantamount theoretical activity. The latter must be hold up by a varied set of tools able to rationalize, explain and predict the operation principles of the devices. However, in the broad context of multi-scale computational nanoelectronics, there is currently a lack of simulation tools connecting atomistic descriptions with semi-classical mesoscopic device-level simulations and able to properly explain the performance of many state-of-the-art devices. To contribute to filling this gap we present a multi-scale approach that combines fine-level material calculations with a semi-classical drift-diffusion transport model. Its use is exemplified by assessing 2DM field effect transistors with strained channels, showing excellent capabilities to capture the changes in the crystal structure and their impact into the device performance. Interestingly, we verify the capacity of strain in monolayer GaSe to enhance the conduction of one type of carrier, enabling the possibility to mimic the effect of chemical doping on 2D materials. These results illustrate the great potential of the proposed approach to bridge levels of abstraction rarely connected before and thus contribute to the theoretical modeling of state-of-the-art 2DM-based devices.

[Adaptation of psychiatric practice in public and private mental health institutions of the City of Buenos Aires during the COVID-19 pandemic]

BACKGROUND

One of the most significant indirect impacts of the COVID-19 pandemic will be seen on the mental health of the population. On this study, we will take into account the adapting capacity that the most representative mental health services (MHS) of Buenos Aires (BA) City have had as to this new situation.

METHODS

We designed an online survey including 10 self-administered closed questions, strictly anonymous. It has been sent to targeted professionals who work in public and private MHS of BA after 2 months of the beginning of the lockdown.

RESULTS

We got 38 answers. 2 professionals rejected to answer. 34% belonged to private institutions and 66% to public ones. 81% of the total were able to implement online assistance but only 24% had been trained on how to treat patients in this context. 69% of the private and 12% of the public sector professionals informed to have been trained on telemedicine tools. 69% of the private and 36% of the public sector professionals informed to have prepared materials for the users on telemedicine resources. 68% mentioned that their service was properly organized. 40% of the public sector professionals may have been reassigned to work on tasks related to the pandemic. 40% of the total informed a reduced capacity of assistance.

CONCLUSIONS

The MHS of BA may have been able to migrate their assistance to telemedicine, however we have noticed differences in the training levels. A better capacity of training on this modality might be needed.

Multi-scale analysis of radio-frequency performance of 2D-material based field-effect transistors

Two-dimensional materials (2DMs) are a promising alternative to complement and upgrade high-frequency electronics. However, in order to boost their adoption, the availability of numerical tools and physically-based models able to support the experimental activities and to provide them with useful guidelines becomes essential. In this context, we propose a theoretical approach that combines numerical simulations and small-signal modeling to analyze 2DM-based FETs for radio-frequency applications. This multi-scale scheme takes into account non-idealities, such as interface traps, carrier velocity saturation, or short channel effects, by means of self-consistent physics-based numerical calculations that later feed the circuit level via a small-signal model based on the dynamic intrinsic capacitances of the device. At the circuit stage, the possibilities range from the evaluation of the performance of a single device to the design of complex circuits combining multiple transistors. In this work, we validate our scheme against experimental results and exemplify its use and capability assessing the impact of the channel scaling on the performance of MoS₂-based FETs targeting RF applications.

Resistive Switching and Charge Transport in Laser-Fabricated Graphene Oxide Memristors: A Time Series and Quantum Point Contact Modeling Approach

This work investigates the sources of resistive switching (RS) in recently reported laser-fabricated graphene oxide memristors by means of two numerical analysis tools linked to the Time Series Statistical Analysis and the use of the Quantum Point Contact Conduction model. The application of both numerical procedures points to the existence of a filament connecting the electrodes that may be interrupted at a precise point within the conductive path, resulting in resistive switching phenomena. These results support the existing model attributing the memristance of laser-fabricated graphene oxide memristors to the modification of a conductive path stoichiometry inside the graphene oxide.

Assessment of three electrolyte-molecule electrostatic interaction models for 2D material based BioFETs

BioFETs based on two-dimensional materials (2DMs) offer a unique opportunity to enhance, at a low cost, the sensitivity of current biosensors enabling the design of compact devices compatible with standard CMOS technology. The unique combination of large exposed surface areas and minimal thicknesses of 2DMs is an outstanding feature for these devices, and the assessment of their behaviour requires combined experimental and theoretical efforts. In this work we present a 2D-material based BioFET simulator including complex electrolyte reactions and analysing different models for the electrolyte-molecule interaction. These models describe how the molecular charge is screened by the electrolyte ions when their distributions are modified. The electrolyte simulation is validated against experimental results as well as against the analytical predictions of the Debye-Hückel approximation. The role of the electrolyte charge screening as well as the impact of the interaction model on the device responsivity are analysed in detail. The results are discussed in order to conclude about the consequences of employing different interaction approximations for the simulation of BioFETs and more generally on the correct modelling of biomolecule-device interaction in BioFETs.

A straight choice: avoiding septal re-deviation using titanium plates. A 16 year retrospective patient follow-up evaluation

BACKGROUND

To propose a new surgical technique for fixing the nasal septum to the midline, for long term prevention of nasal obstruction, in secondary and select cases of primary septoplasty.

METHODOLOGY

Retrospective study, within hospital medical center.

PATIENTS

Two hundred and twenty two patients who underwent septoplasty. Data collection occurred consecutively between March 1st of 2000 and May 1st 2016. Twenty six percent females and seventy four percent males.

MAIN OUTCOME MEASURES

Patterns of septal deformity, materials used for titanium plates, surgical results, symptom improvement, and surgical complications were investigated.

RESULTS

A total of 222 patients were included in this study. 163 patients (73%) had no previous nasal surgery. Fifty nine patients (27%) presented with a previous nasal surgery. Sixteen year follow up included more than 90% of patients and resulted in an overall 2.7% revision rate.

CONCLUSIONS

The use of titanium plate for septoplasty has shown to be simple, safe, and easy to learn technique in both secondary and select cases of primary septoplasty. Most importantly the results indicate a long term prevention of the.

Bioflora probiotic in immunomodulation and prophylaxis of intestinal bacterial translocation in rats

The immunomodulator effect of Bioflora probiotic on T (CD4+) and B (CD20) lymphocytes in gastrointestinal mucosa and intestinal bacterial translocation was studied using Wistar rats (n = 10 per group). Two experiments were used: (I) stress with immobilization and water immersion at 22 degrees C for 7 h plus the application of indomethacin (Indo) 10 mg/kg SC every 24 h for 3 days (comparator group), and (II) stress experiment I with the addition of 1 mL of Bioflora applied through a orogastric tube every 12 h for 3 days. At the 4th day, in asepsis, a dissection laparotomy of liver, spleen, mesenteric lymphatic nodes, and cecum was performed for microbiological culture, and stomach, ileum, and colon were also dissected for immunohistochemical and quantification of CD4+ and CD20. Findings in experiment I revealed cecum bacterial overdevelopment of 6 x 10(10) +/- 2.3 x 10(9) colony-forming units (CFU) (P < 0.01) and positive cultures in liver, spleen, and all mesenteric lymphatic nodes. On the other hand, in the group treated with Probiotic Bioflora, cecum without overdevelopment (3 x 10(6) +/- 1.3 x 10(5) CFU), negative cultures in liver and spleen, and in lymphatic nodes two positive and eight negative cultures for E. coli and P. vulgaris (P < 0.01) were observed. Immunohistochemistry revealed a relevant increase of T lymphocytes (CD4+) in ileum and colon.

CONCLUSIONS

Bioflora probiotic was shown to be an intestinal immunomodulator that induced increased T (CD4+) lymphocytes that also offer prophylaxis of intestinal bacterial translocation in a stressed rat model.

Guidelines for the Assessment Process (GAP): A Proposal for Discussion

Summary: Current existing or proposed standards and guidelines in the field of psychological assessment are confined to psychological tests and psychological testing. But tests constitute only one category of psychological assessment procedures, and testing is only one of many available strategies or classes of actions in the course of the assessment process. Tests and testing are closely linked to a certain approach to psychological assessment, i. e., the psychometric one. This is one reason why it is relatively easy to formulate and establish standards or guidelines in the case of psychological tests and testing. The much more comprehensive assessment process is an indispensable part of any approach to psychological assessment, even of those that do not use psychometric tests. This makes the formulation of guidelines for the assessment process an ambitious and very difficult enterprise. But it can be done, at least at the level of recommendations that could help the assessor to cope with the complexities and demands of assessment processes in various contexts of psychological assessment. The European Association of Psychological Assessment (EAPA) decided to sponsor the development of Guidelines for the Assessment Process (GAP), setting up a Task Force for this specific purpose. The GAP introduced in this paper are intended as a first proposal to initiate a broad discussion about how to improve the practice of psychological assessment and the education and training of psychological assessors.

Proinflammatory cytokine expression in gastric tissue from children with Helicobacter pylori-associated gastritis

BACKGROUND

Helicobacter pyloriinfection of the gastric mucosa in humans is usually acquired early in life. The chronic inflammation that ensues involves the increased production of inflammatory cytokines. Published data on production of these mediators by gastric mucosa of H. pylori-infected children are few.

METHODS

Seventy-nine children, aged 5 to 18 years, referred for upper gastrointestinal endoscopy to four separate hospitals in Chile, were studied. The concentrations of interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor alpha were measured in homogenates of gastric mucosal biopsy specimens. Cytokine expression was confirmed by reverse transcription polymerase chain reaction. These data were correlated with the patients' clinical, histologic and sociodemographic status.

RESULTS

Patient rate of colonization by H. pylori was inversely correlated with socioeconomic status (P < 0.005) and positively correlated with age (P < 0.0025). In gastric mucosa, concentrations of IL-1beta, IL-8, and tumor necrosis factor alpha were all significantly higher in H. pylori-positive patients than in H. pylori-negative patients and in patients who had histologic gastritis than in those with normal gastric mucosa. In patients with peptic ulcer disease, only IL-1beta and IL-8 concentrations were significantly elevated when compared with those of patients without ulcers. Interleukin-6 concentrations were comparable among the different groups analyzed.

CONCLUSIONS

This study suggests that increased gastric mucosal production of the proinflammatory cytokines IL-1beta and IL-8 is probably involved in H. pylori-associated gastric damage in children and may be crucial in determining the different clinical outcomes.

Elevated expression of glucose transporter-1 in hypothalamic ependymal cells not involved in the formation of the brain-cerebrospinal fluid barrier

Glucose transporters play an essential role in the acquisition of glucose by the brain. Elevated expression of glucose transporter-1 has been detected in endothelial cells of the blood-brain barrier and in choroid plexus cells of the blood-cerebrospinal fluid barrier. On the other hand, there is a paucity of information on the expression of glucose transporters in the ependymal cells that line the walls of the cerebral ventricles. The tanycytes are specialized ependymal cells localized in circumventricular organs such as the median eminence that can be segregated into at least three types, alpha, beta1 and beta2. The beta2 tanycytes form tight junctions and participate in the formation of the cerebrospinal fluid-median eminence barrier. Using immunocytochemistry and in situ hybridization, we analyzed the expression of hexose transporters in rat and mouse hypothalamic tanycytes. In both species, immunocytochemical analysis revealed elevated expression of glucose transporter-1 in alpha and beta1 tanycytes. Intense anti-glucose transporter-1 staining was observed in cell processes located throughout the arcuate nucleus, in the end-feet reaching the lateral sulcus of the infundibular region, and in cell processes contacting the hypothalamic capillaries. On the other hand, there was very low expression of glucose transporter-1 in beta2 tanycytes involved in barrier function. In contrast with the results of the cytochemical analysis, in situ hybridization revealed that tanycytes alpha, beta1, and beta2 express similar levels of glucose transporter-1 mRNA. Further analysis using anti-glial fibrillary acidic protein antibodies to identify areas rich in astrocytes revealed that astrocytes were absent from areas containing alpha and beta1 tanycytes, but were abundant in regions containing the barrier-forming beta2 tanycytes. Overall, our data reveal a lack of correlation between participation in barrier function and expression of glucose transporter-1 in hypothalamic tanycytes. Given the virtual absence of astrocytes in areas rich in alpha and beta1 tanycytes, we speculate whether the tanycytes might have astrocyte-like functions and participate in the metabolic coupling between glia and neurons in the hypothalamic area.

Gastrointestinal damage induced by celecoxib and rofecoxib in rats

Five experimental models were developed in different groups of Wistar rats (N = 15) to study selective COX-2-inhibitor NSAIDs such as celecoxib and rofecoxib, as follows: (1) dose-dependent oral Celecoxib and Rofecoxib for 5 days, and 24 hr after oral indomethacin; (2) Same as 1 but subcutaneously; (3) gastric ulcer induced by glacial acetic acid; (4) duodenal ulcer induced by cysteamine; and (5) stress by immobilization and immersion in water at 15 degrees C for 6 hr. Celecoxib and Rofecoxib, either orally or subcutaneously, did not produce necrotic lesions in healthy gastrointestinal mucosa (0%), showing normal histology. In contrast, previously indomethacin-induced lesions were aggravated (90%, P < 0.001). Total necrosis in the small intestine as well as increased ulcers and perforation of gastric and duodenal ulcers induced by acetic acid and cysteamine were observed. There was also aggravation of the necrotic gastric area in stress (60-90%, P < 0.05). Celecoxib and rofecoxib showed neutrophilia (5000/mm3) similar to that with indomethacin. In contrast, there was no leukocyte infiltration in the gastric múcosa; thus, we can consider it a selective COX-2 NSAID. In conclusion, celecoxib and rofecoxib at doses causing COX-2 but not COX-1 inhibition did not produce toxic lesions in healthy gastrointestinal mucosa, yielding a broad therapeutic margin. In contrast, when administered in altered gastrointestinal mucosa, they aggravated and complicated gastric ulcers as well as necrosis in the small intestine, consequently restricting their clinical use.

[Gastrointestinal damage induced by celecoxib and rofecoxib in rats]

Five experimental models were carried out in different groups of Wistar rats (n = 15) in order to study selective (cyclo-oxygenase) COX-2 non-steroid antiinflammatory inhibitors, such as celecoxib and rofecoxib, as follows: 1) Dose-dependent oral celecoxib and rofecoxib for 5 days, and 24 hours after oral indomethacin. 2) Same as 1, but subcutaneously. 3) Gastric ulcer induced by means of glacial acetic acid. 4) Duodenal ulcer induced by means of cysteamine. 5) Stress due to being kept under restraint and immersion in water at 15 degrees C for 6 hours. Celecoxib and rofecoxib, either orally or subcutaneously, did not produce necrotic injuries in healthy gastrointestinal mucosa (0%), showing normal histology. On the other hand, the injuries previously induced by indomethacin worsened (90%, p < 0.001). Total necrosis of small intestine as well as increased ulcer and perforation of gastric and duodenal ulcers induced by acetic acid and cysteamine were observed. There was also worsening of gastric necrotic area with stress (60-90%, p < 0.05). Celecoxib and rofecoxib showed neutrophilia (5,000/mm3) similar to that presented by indomethacin, but there was no leukocyte infiltration in the gastric mucosa; thus we can consider it a COX-2 selective NSAID (non-steroidal anti-inflammatory drug).

CONCLUSION

Dose-dependent administration of celecoxib and rofecoxib as COX-2 inhibitors and non-COX-1 inhibitors, respectively, did not produce toxic injuries on healthy gastrointestinal mucosa, thus providing a broad therapeutic spectre. On the other hand, when administered in presence of altered gastrointestinal mucosa, they worsened and complicated gastric ulcers, and also induced necrosis in the small intestine, thereby restricting their clinical use.

Outcome of patients with malignant hypertension and end-stage renal failure treated by long-term hemodialysis

Malignant hypertension is associated with high mortality and morbidity usually caused by cardiovascular events. The course and prognosis of malignant hypertension patients treated with renal replacement therapy has not been thoroughly investigated. In the present work, we compared the clinical evolution and survival of 24 end-stage renal failure malignant hypertension patients with that of a group of individually matched renal failure patients admitted to the same dialysis center during a period of 21 years. Survival rates at 1, 5 and 8 years were 87, 82 and 50% for malignant hypertension patients and 87, 75 and 65% for controls, respectively (p = 0.766, NS). Nonfatal cardiovascular complications occurred in 2 individuals of each group. The most important cause of death in both groups was cardiovascular. The frequency of fatal cardiovascular events was similar in the two groups: 64% of deaths for malignant hypertension and 71% for controls (NS). In conclusion, previous malignant hypertension did not increase the risk of patients in long-term hemodialysis in our series.

Expression of the hexose transporters GLUT1 and GLUT2 during the early development of the human brain

We used immunohistochemistry with anti-glucose transporter antibodies to document the presence of facilitative hexose transporters in the fetal human brain. GLUT1 is expressed in all regions of the fetal brain from ages 10 to 21 weeks. GLUT1 was present in the endothelial cells of the brain capillaries, the epithelial cells of the choroid plexus and neurons. High expression of GLUT2 was observed in the granular layer of the cerebellum in brains 21 weeks old, but GLUT2 immunoreactivity was absent at earlier stages. GLUT3 and GLUT4 immunoreactivities were absent at all stages studied. GLUT5 immunoreactivity was evident only in the cerebellar region of 21-week old fetal brains. We conclude that GLUT1 plays a fundamental role in early human brain development. The data also suggest that the cerebellum of the developing brain has the capacity to transport fructose, a substrate that has not been previously identified as a source of metabolic energy in the adult human brain.