Design of an experimental setup for delivering intracortical microstimulation in vivo via Spiking Neural Network

Electroceutical approaches for the treatment of neurological disorders, such as stroke, can take advantage of neuromorphic engineering, to develop devices able to achieve a seamless interaction with the neural system. This paper illustrates the development and test of a hardware-based Spiking Neural Network (SNN) to deliver neural-like stimulation patterns in an open-loop fashion. Neurons in the SNN have been designed by following the Hodgkin-Huxley formalism, with parameters taken from neuroscientific literature. We then built the set-up to deliver the SNN-driven stimulation in vivo. We used deeply anesthetized healthy rats to test the potential effect of the SNN-driven stimulation. We analyzed the neuronal firing activity pre- and post-stimulation in both the primary somatosensory and the rostral forelimb area. Our results showed that the SNN-based neurostimulation was able increase the spontaneous level of neuronal firing at both monitored locations, as found in the literature only for closed-loop stimulation. This study represents the first step towards translating the use of neuromorphic-based devices into clinical applications.Clinical Relevance- Stroke represents one of the leading causes of long-term disability and death worldwide. Intracortical microstimulation is an effective approach for restoring lost sensory motor integration by promoting plasticity among the affected brain areas. Stimulation delivered via neuromorphic-based open-loop systems (i.e. neuromorphic prostheses) can pave the way to novel electroceutical strategies for brain repair.

Digital hardware implementation of a stochastic two-dimensional neuron model

This study explores the feasibility of stochastic neuron simulation in digital systems (FPGA), which realizes an implementation of a two-dimensional neuron model. The stochasticity is added by a source of current noise in the silicon neuron using an Ornstein-Uhlenbeck process. This approach uses digital computation to emulate individual neuron behavior using fixed point arithmetic operation. The neuron model's computations are performed in arithmetic pipelines. It was designed in VHDL language and simulated prior to mapping in the FPGA. The experimental results confirmed the validity of the developed stochastic FPGA implementation, which makes the implementation of the silicon neuron more biologically plausible for future hybrid experiments.

Anti-inflammatory effect of a Nuphar lutea partially purified leaf extract in murine models of septic shock

ETHNOPHARMACOLOGICAL RELEVANCE

Various plant organs of Nuphar lutea (L.) SM. (Nymphaeaceae) are used in traditional medicine for the treatment of arthritis, fever, aches, pains and inflammation. The main purpose of this study was to determine the anti-inflammatory effect of Nuphar lutea leaf extract (NUP) in two septic shock models: (1) Survival of mice challenged with a lethal dose of LPS, determination of pro-inflammatory and anti-inflammatory cytokines in serum, as well as in peritoneal macrophages in cell culture. (2) The effect of NUP in a murine model of fecal-induced peritonitis.

MATERIALS AND METHODS

NUP pre-treatment partially protected mice in two models of acute septic shock. We concluded that NUP is anti-inflammatory by inhibiting the NF-κB pathway, modulating cytokine production and ERK phosphorylation.

RESULTS

A significant average survival rate (60%) of LPS lethally-challenged mice was achieved by pre-treatment with NUP. In addition, NUP pre-treatment reduced nuclear NF-κB translocation in peritoneal macrophages. The production of pro-inflammatory cytokines, TNF-α, IL-6 and IL-12, in the sera of LPS-treated mice or in the supernatants of peritoneal macrophages stimulated with LPS for 2-6 h was also decreased by NUP. Pre-treatment with NUP caused a significant increase in the anti-inflammatory cytokine IL-10. The NUP pre-treatment reduced and delayed mortality in mice with fecal-induced peritonitis. Our studies also revealed that NUP pre-treatment induced a dose-dependent phosphorylation of ERK in peritoneal macrophages. Since most of the reports about the anti-inflammatory effect of Nuphar lutea refer to rhizome and root powder and extracts, it is important to clarify the effectiveness of leaf extract as a source for such activity.

CONCLUSION

NUP pre-treatment partially protected mice in two models of acute septic shock. We concluded that NUP is anti-inflammatory by inhibiting the NF-κB pathway, modulating cytokine production and ERK phosphorylation.

Adding luteinizing hormone to follicle stimulating hormone from day 3-5 improves pregnancy outcome in normal but not poor responders using gonadotropin releasing hormone antagonists

PURPOSE

To determine if the addition of luteinizing hormone (LH) to follicle stimulating hormone (FSH) stimulation for controlled ovarian hyperstimulation (COH) protocols using gonadotropin releasing hormone (GnRH) antagonists improves pregnancy rates following in vitro fertilization-embryo transfer (IVF-ET).

MATERIALS AND METHODS

All IVF-ET cycles using a GnRH antagonist were evaluated according to whether FSH was used exclusively or if LH was added. The cycles were further stratified according to age (< or = 39 and 40-42 years) and according to good responders (> or = five oocytes retrieved) or poor responders (< or = four oocytes).

RESULTS

Combining all data, a significantly higher clinical and live delivered pregnancy rates were found in those adding LH (34.7% and 32.3%) vs those taking all FSH (33.4% and 25.8%). The only subgroup not showing this effect was the women aged 40-42 years with diminished oocyte reserve.

CONCLUSIONS

LH should be added not only to COH protocols using GnRH agonists but also those using GnRH antagonists.

Long-term glutamate supplementation failed to protect against peripheral neurotoxicity of paclitaxel

Toxic peripheral neuropathy is still a significant limiting factor for chemotherapy with paclitaxel (PAC), although glutamate and its closely related amino acid glutamine were claimed to ameliorate PAC neurotoxicity. This pilot trial aimed to evaluate the role of glutamate supplementation for preventing PAC-induced peripheral neuropathy in a randomized, placebo-controlled, double-blinded clinical and electro-diagnostic study. Forty-three ovarian cancer patients were available for analysis following six cycles of the same PAC-containing regimen: 23 had been supplemented by glutamate all along the treatment period, at a daily dose of three times 500 mg (group G), and 20 had received a placebo (group P). Patients were evaluated by neurological examinations, questionnaires and sensory-motor nerve conduction studies. There was no significant difference in the frequency of signs or symptoms between the two groups although neurotoxicity symptoms presented mostly with lower scores of severity in group G. However, this difference reached statistical significance only with regard to reported pain sensation (P = 0.011). Also the frequency of abnormal electro-diagnostic findings showed similarity between the two groups (G: 7/23 = 30.4%; P: 6/20 = 30%). This pilot study leads to the conclusion that glutamate supplementation at the chosen regimen fails to protect against peripheral neurotoxicity of PAC.

Emergency hysteroscopic treatment of acute severe uterine bleeding

The aim of this pilot feasibility study was to investigate the efficacy and safety of hysteroscopy in the diagnosis and treatment of acute severe uterine bleeding. Forty-one women (mean age, 54 years) who underwent emergency hysteroscopy were assessed. In 40 women, a benign organic cause was found. In one postmenopausal patient, endometrial carcinoma was detected in endometrial chips and was managed with hysterectomy. None of the women with benign lesions required further surgery within the first postoperative year. One underwent hysterectomy at 18 months for new-onset fibromyomas. Hysteroscopy was found to be an effective tool for treating heavy uterine bleeding. It also prevented future episodes of severe bleeding in more than half the patients during 20 months of follow-up.

An investigation into the physical accessibility to wheelchair bound students of an Institution of Higher Education in South Africa

PURPOSE

A descriptive cross-sectional study was undertaken to establish the ease of accessibility to wheelchair bound students of the campus of a large institution of higher education in South Africa. Accessibility was defined not simply in terms of access to buildings, but also of the added time and distance traveled by wheelchair bound students on the campus.

METHODS

Five different faculties were randomly selected and typical routes travelled by a first year student in each faculty established. The shortest possible distances were mapped out for each faculty and measured using a metre wheel. For those in wheelchairs, this distance included the distance to ramps and to lifts. Mean speeds were used to determine the time taken to travel the measured distances. A checklist was used to measure the physical accessibility of the 18 buildings concerned.

RESULTS

The total mean distance traveled between lecture theatre changeover by wheelchair-bound students was 402 metres (range 278-689 m for the different faculties), which was a mean difference of 66 m (range 11-145 m) longer than for ambulant students. The mean time taken was 17 minutes (range 11-28 minutes), which was 11 minutes (range 8-19 minutes) longer than for ambulant students. The Faculty of Mechanical Engineering fared the worst, at 689 metres and 28 minutes between changeover. Two of the 18 buildings measured were fully accessible, while three were completely inaccessible. Inaccessible toilets were the most common problem.

CONCLUSIONS

Wheelchair-bound students consistently had to travel further and for longer times between lecture theatres in all the faculties measured. The students would therefore be unable to reach their lectures within the 10 minute time allocated by the university. The inaccessibility of the buildings limits the full integration of wheelchair-bound students into campus life. Certain administrative changes might assist in improving the ease of accessibility. Architectural adaptations, although more costly, might also prove to be effective.

Treatment of the twisted cystic ovary with normal blood flow by simple aspiration

Simple aspiration was performed in eight patients to correct torsion of cystic ovaries with normal blood flow, imaged by the colour Doppler technique. Abdominal pain resolved spontaneously following aspiration. Symptoms recurred in three patients, necessitating detorsion by laparoscopy. Normal follicular growth was assessed within 3 months in the non-pregnant patients.

Physical and transcriptional map of the hereditary inclusion body myopathy locus on chromosome 9p12-p13

Hereditary inclusion body myopathy (HIBM) is a group of neuromuscular disorders characterised by adult-onset, slowly progressive distal and proximal muscle weakness and typical muscle pathology. Previously, we have mapped the gene responsible for a recessive form of HIBM to chromosome 9p1 and narrowed the interval to one single YAC clone of 1 Mb in size. As a further step towards the identification of the HIBM gene, we have constructed a detailed physical and transcriptional map of this region. A high resolution BAC contig that includes the HIBM critical region, flanked by marker 327GT4 and D9S1859, was constructed. This contig allowed the precise localisation of 25 genes and ESTs to the proximal region of chromosome 9. The expression pattern of those mapped genes and ESTs was established by Northern blot analysis. In the process of refining the HIBM interval, 13 new polymorphic markers were identified, of which 11 are CA-repeats, and two are single nucleotide polymorphisms. Certainly, this map provides an important integration of physical and transcriptional information corresponding to chromosome 9p12-p13, which is expected to facilitate the cloning and identification not only of the HIBM gene, but also other disease genes which map to this region.

Elective cytogenetic amniocentesis in the third trimester for pregnancies with high risk factors

The aim of the present study was to report the findings in 14 women with extremely high risk ('precious') pregnancies, 5 of whom had twins, who underwent elective third-trimester cytogenetic amniocentesis. There were no procedure-related complications, and all newborns weighed more than 2000 g and showed normal development. This practice is accepted under Israeli law and our institutional policy. This preliminary work does not attempt to answer the moral and ethical questions surrounding the use of third (versus second) trimester amniocentesis in either 'precious' or normal pregnancies. We do show, however, that the procedure is safe and may constitute a good alternative for patients who are unwilling to accept the risks of early fetal karyotyping.

Chamber-specific cardiac expression of Tbx5 and heart defects in Holt-Oram syndrome

To further define the role of a T-box transcription factor, Tbx5, in cardiac development, we have examined its expression in the developing mouse and chick heart and correlated this pattern with cardiac defects caused by human TBX5 mutations in Holt-Oram syndrome. Early in the developing heart, Tbx5 is uniformly expressed throughout the entire cardiac crescent. Upon formation of the linear heart tube, Tbx5 is expressed in a graded fashion, stronger near the posterior end and weaker at the anterior end. As the heart tube loops, asymmetric Tbx5 expression continues; Tbx5 is expressed in the presumptive left ventricle, but not the right ventricle or outflow tract. This pattern of expression is maintained in more mature hearts. Expression in the ventricular septum is restricted to the left side and is contiguous with left ventricular free wall expression. Trabeculae, vena cavae (inferior and superior), and the atrial aspect of the atrioventricular valves also express high levels of Tbx5. These patterns of Tbx5 expression provide an embryologic basis for the prevalence of atrial septal defects (ostium primum and secundum), ventricular muscular septal defects, and left-sided malformations (endocardial cushion defects, hypoplastic left heart, and aberrant trabeculation) observed in patients with Holt-Oram syndrome.

Fine-structure mapping of the hereditary inclusion body myopathy locus

The gene responsible for a recessive form of hereditary inclusion body myopathy (HIBM) has previously been mapped to a 10-cM interval on chromosome 9p1-q1. We report the results of further mapping studies using two-point linkage analyses and linkage disequilibrium analyses with 20 HIBM families. We demonstrate that the HIBM gene (HGMW-approved symbol IBM2) lies between loci D9S1791 and D9S50, which are about 1 Mb apart. Genetic analyses in 56 affected individuals of Persian, Afghani, and Iraqi Jewish descent demonstrated a common haplotype at these loci, indicating that a founding mutation accounts for disease in these related ethnic groups. beta-Tropomyosin, an abundant skeletal muscle protein that maps within 1 cM of D9S1791, was excluded as the disease gene because an intragenic polymorphism did not exhibit linkage disequilibrium in HIBM probands. We conclude that the disease gene resides in a 1-Mb interval on chromosome 9 and speculate that a novel muscle protein encoded there is mutated in HIBM.

Mutations in human TBX5 [corrected] cause limb and cardiac malformation in Holt-Oram syndrome

Holt-Oram syndrome is characterized by upper limb malformations and cardiac septation defects. Here, we demonstrate that mutations in the human TBX5 gene underlie this disorder. TBX5 was cloned from the disease locus on human chromosome 12q24.1 and identified as a member of the T-box transcription factor family. A nonsense mutation in TBX5 causes Holt-Oram syndrome in affected members of one family; a TBX5 missense mutation was identified in affected members of another. We conclude that TBX5 is critical for limb and heart development and suggest that haploinsufficiency of TBX5 causes Holt-Oram syndrome.

Chicken ovalbumin upstream promoter--transcription factor (COUP-TF) expression in human endometrial cancer cell lines

COUP-TF is an orphan member of the steroid receptor superfamily. COUP-TF down-regulates hormonal induction by other steroid receptors involved in cell proliferation and differentiation. Previous study has suggested a role in gynecological adenocarcinoma. In the present study we evaluated COUP-TF expression in endometrial cancer. Fourteen permanent endometrial cancer cell lines were established front the primary site of 14 endometrial cancer patients. Immunocytochemistry for COUP-TF-like activity was performed using an affinity selected polyclonal rabbit-derived antibody in an immunoperoxidase staining technique. The staining intensity and cell surface area were quantified by image analysis. By immunostain 2 cell lines were COUP-TF (+), 6 (+ +) and 6 (+ + +). Quantitative differences in staining intensity and cell surface area were not significant in these groups. All cell lines tested were immunocytochemically negative for estrogen and progesterone receptors. COUP-TF is a new factor involved in endometrial cancer cell differentiation and growth, especially in estrogen receptor negative tumors.

Cloning, expression, and chromosomal location of SHH and IHH: two human homologues of the Drosophila segment polarity gene hedgehog

The hedgehog genes encode signaling molecules that play a role in regulating embryonic morphogenesis. We have cloned and sequenced human cDNA copies of two of these genes, SHH and IHH. The SHH clone includes the full coding sequence and encodes a protein 92.4% identical to its murine homologue. The IHH clone is 89% complete and encodes a protein 94.6% identical to its murine homologue. IHH is expressed in adult kidney and liver. SHH expression was not detected in adult tissues examined; however, it is expressed in fetal intestine, liver, lung, and kidney. SHH mapped to chromosome 7q and IHH to chromosome 2 by PCR with DNA from a panel of rodent-human somatic cell hybrids. To identify the chromosomal location of SHH more precisely, a P1 genomic clone of SHH was isolated. This phage contained a CA repeat sequence tagged site that was used to map SHH relative to a polysyndactyly disease locus, using DNA prepared from affected and unaffected members of a large pedigree. SHH is closely linked, but distinct from the polysyndactyly disease locus at 7q36 (maximum lod score = 4.82, theta = 0.05) tightly linked to the EN2 locus. The murine homologues Shh, Ihh, and Dhh were mapped using (C57BL/6J x Mus spretus)F1 x C57BL/6J interspecific backcross. Shh mapped to a position 0.6 cM distal to En2 and 1.9 cM proximal to Il6 on mouse chromosome 5. This location is closely linked but distinct from the murine limb mutation Hx and syntenic to human chromosome 7q36.

Mutations in the human Ca(2+)-sensing receptor gene cause familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism

We demonstrate that mutations in the human Ca(2+)-sensing receptor gene cause familial hypocalciuric hypercalcemia (FHH) and neonatal severe hyperparathyroidism (NSHPT), two inherited conditions characterized by altered calcium homeostasis. The Ca(2+)-sensing receptor belongs to the superfamily of seven membrane-spanning G protein-coupled receptors. Three nonconservative missense mutations are reported: two occur in the extracellular N-terminal domain of the receptor; the third occurs in the final intracellular loop. One mutated receptor identified in FHH individuals was expressed in X. laevis oocytes. The expressed wild-type receptor elicited large inward currents in response to perfused polyvalent cations; a markedly attenuated response was observed with the mutated protein. We conclude that the mammalian Ca(2+)-sensing receptor "sets" the extracellular Ca2+ level and is defective in individuals with FHH and NSHPT.

The gene responsible for familial hypocalciuric hypercalcemia maps to chromosome 3q in four unrelated families

Familial hypocalciuric hypercalcemia (FHH) is an autosomal dominant syndrome of unknown aetiology characterized by lifelong elevation in serum calcium concentration and low urinary calcium excretion. These features suggest that the causal gene is important for maintenance of extracellular calcium homeostasis by the parathyroid gland and kidney. To identify the chromosomal location of FHH gene(s), we clinically evaluated 114 individuals in four unrelated affected families and performed linkage analyses. The disease gene mapped to the long arm of chromosome 3 in each family (combined maximum multipoint lod score = 20.67). We suggest that this is the predominant FHH locus and anticipate that identification of the FHH gene will improve our understanding of the molecular basis for physiologic and pathologic regulation of calcium.

Characteristics and prognostic implications of myosin missense mutations in familial hypertrophic cardiomyopathy

BACKGROUND

Familial hypertrophic cardiomyopathy is characterized by a variable degree of myocardial hypertrophy and a wide range of symptoms. Different mutations in the beta cardiac myosin heavy-chain gene have been identified in three affected families. However, neither the proportion of cases attributable to myosin mutations nor the effects of different mutations on clinical outcome are known.

METHODS

Using a ribonuclease protection assay, we screened the beta cardiac myosin heavy-chain genes of probands from 25 unrelated families with familial hypertrophic cardiomyopathy; this assay is a sensitive method for detecting the presence and location of mutations. We further defined the mutations by analyzing their nucleotide sequences. The clinical features of the disease were compared in families with various myosin mutations.

RESULTS

Seven mutations in the beta cardiac myosin heavy-chain gene were identified in 12 of the 25 families. All were missense mutations (i.e., causing the substitution of a single amino acid) clustered in the head and head-rod junction regions of the molecule. Six mutations resulted in a change in the charge of the amino acid. Patients with mutations that changed the charge of the altered amino acid (such as that from arginine to glutamine at nucleotide 403 or from arginine to cysteine at nucleotide 453) had a significantly shorter life expectancy (mean age at death, 33 years), whereas patients with the one mutation that did not produce a change in charge (Val606Met) had nearly normal survival. However, patients with different mutations did not differ appreciably in their clinical manifestations of familial hypertrophic cardiomyopathy.

CONCLUSIONS

Different missense mutations in the beta cardiac myosin heavy-chain gene can be identified in approximately 50 percent of families with hypertrophic cardiomyopathy. In those families, a definite genetic diagnosis can be made in all members. Since the location of a mutation or its DNA-sequence alteration (or both) appears to influence survival, we suggest that the precise definition of the disease-causing mutation can provide important prognostic information about affected members.

Mapping a gene for familial hypertrophic cardiomyopathy to chromosome 14q1

To identify the chromosomal location of a gene responsible for familial hypertrophic cardiomyopathy, we used clinical and molecular genetic techniques to evaluate the members of a large kindred. Twenty surviving and 24 deceased family members had hypertrophic cardiomyopathy; 58 surviving members were unaffected. Genetic-linkage analyses were performed with polymorphic DNA loci dispersed throughout the entire genome, to identify a locus that was inherited with hypertrophic cardiomyopathy in family members. The significance of the linkage detected between the disease locus and polymorphic loci was assessed by calculating a lod score (the logarithm of the probability of observing coinheritance of two loci, assuming that they are genetically linked, divided by the probability of detecting coinheritance if they are unlinked). A DNA locus (D14S26), previously mapped to chromosome 14 and of unknown function, was found to be coinherited with the disease in this family. No instances of recombination were observed between the locus for familial hypertrophic cardiomyopathy and D14S26, yielding a lod score of +9.37 (theta = 0). These data indicate that in this kindred, the odds are greater than 2,000,000,000:1 that the gene responsible for familial hypertrophic cardiomyopathy is located on chromosome 14 (band q1).