SREDA: An Uncommon and Misleading EEG Rhythm

Subclinical Rhythmic Electroencephalographic Discharges of Adults (SREDA) is a benign EEG variant characterized by sharply contoured rhythmic theta activity occurring bilaterally with maximum activity over the parietal or the posterior head region. These paroxysms are not associated with any objective or subjective clinical manifestations. SREDA, the rarest and last reported benign EEG pattern with no known clinical significance yet, is detailed in this case report. We provide the case of a gentleman with epilepsy who underwent vEEG recording in our lab. The described case is interesting due to its EEG characteristics as well as its clinical picture, which misled us for at least a while. It provides an illustration of how over interpretation of normal EEG patterns may result in an incorrect diagnosis.

Satisfaction among persons with epilepsy towards physical consultation versus online video consultation for follow-up

PURPOSE

Telemedicine gained popularity in the setting of the COVID-19 pandemic. We aimed to study the satisfaction levels of persons with epilepsy (PWE) with online video consultation (OVC) and physical consultation (PC).

METHODS

This was a cross-sectional questionnaire-based study conducted in a tertiary referral care center for epilepsy in India. All PWE who had availed of both OVC and PC were included. Those who did not give consent to a questionnaire were excluded. A questionnaire was given to assess patients' satisfaction regarding OVC and PC. Scores for each question for both OVC and PC were compared.

RESULTS

One hundred and forty-one patients who had PC earlier and later availed of OVC from December 2020 to July 2021 formed the cohort. Seventy one patients who responded to the questionnaire were included. 49% and 51% of the patients belonged to urban and rural regions respectively. 8.5% of the patients were off anti-seizure medications (ASM), while 5.6% and 85.9% were on single and multiple ASMs respectively. There were no differences between PC and OVC regarding ease of getting the appointment, privacy during a consultation, patients' perceived chances of missing consultations, and overall comfort and experience on either type of consultation. Physical consultation scored more than OVC in patients' satisfaction with the time doctor spent with them, an opportunity to communicate their queries well, clarifications received from the doctor, and the likelihood of patients recommending the particular type of consultation to others(p < 0.05).

CONCLUSIONS

Online video consultation can be a satisfactory alternative to PC and can improve patient satisfaction if some of the issues in OVC are addressed properly.

First Report of Alfalfa mosaic virus Infecting Tedera (Bituminaria bituminosa (L.) C.H. Stirton var. albomarginata and crassiuscula) in Australia

Tedera (Bituminaria bituminosa (L.) C.H. Stirton vars albomarginata and crassiuscula) is being established as a perennial pasture legume in southwest Australia because of its drought tolerance and ability to persist well during the dry summer and autumn period. Calico (bright yellow mosaic) leaf symptoms occurred on occasional tedera plants growing in genetic evaluation plots containing spaced plants at Newdegate in 2007 and Buntine in 2010. Alfalfa mosaic virus (AlMV) infection was suspected as it often causes calico in infected plants (1,2) and infects perennial pasture legumes in local pastures (1,3). Because AlMV frequently infects Medicago sativa (alfalfa) in Australia and its seed stocks are commonly infected (1,3), M. sativa buffer rows were likely sources for spread by aphids to healthy tedera plants. When leaf samples from plants with typical calico symptoms from Newdegate (2007) and Buntine (2010) were tested by ELISA using poyclonal antisera to AlMV, Bean yellow mosaic virus (BYMV) and Cucumber mosaic virus (CMV), only AlMV was detected. When leaf samples from 864 asymptomatic spaced plants belonging to 34 tedera accessions growing at Newdegate and Mount Barker in 2010 were tested by ELISA, no AlMV, BYMV, or CMV were detected, despite presence of M. sativa buffer rows. A culture of AlMV isolate EW was maintained by serial planting of infected seed of M. polymorpha L. (burr medic) and selecting seed-infected seedlings (1,3). Ten plants each of 61 accessions from the local tedera breeding program were grown at 20°C in an insect-proof air conditioned glasshouse. They were inoculated by rubbing leaves with infective sap containing AlMV-EW or healthy sap (five plants each) using Celite abrasive. Inoculations were always done two to three times to the same plants. When both inoculated and tip leaf samples from each plant were tested by ELISA, AlMV was detected in 52 of 305 AlMV-inoculated plants belonging to 36 of 61 accessions. Inoculated leaves developed local necrotic or chlorotic spots or blotches, or symptomless infection. Systemic invasion was detected in 20 plants from 12 accessions. Koch's postulates were fulfilled in 12 plants from nine accessions (1 to 2 of 5 plants each), obvious calico symptoms developing in uninoculated leaves, and AlMV being detected in symptomatic samples by ELISA, inoculation of sap to diagnostic indicator hosts (2) and RT-PCR with AlMV CP gene primers. Direct RT-PCR products were sequenced and lodged in GenBank. When complete nucleotide CP sequences (666 nt) of two isolates from symptomatic tedera samples and two from alfalfa (Aq-JX112758, Hu-JX112759) were compared with that of AlMV-EW, those from tedera and EW were identical (JX112757) but had 99.1 to 99.2% identities to the alfalfa isolates. JX112757 had 99.4% identity with Italian tomato isolate Y09110. Systemically infected tedera foliage sometimes also developed vein clearing, mosaic, necrotic spotting, leaf deformation, leaf downcurling, or chlorosis. Later-formed leaves sometimes recovered, but plant growth was often stunted. No infection was detected in the 305 plants inoculated with healthy sap. To our knowledge, this is the first report of AlMV infecting tedera in Australia or elsewhere. References: (1) B. A. Coutts and R. A. C. Jones. Ann. Appl. Biol. 140:37, 2002. (2) E. M. J. Jaspars and L. Bos. Association of Applied Biologists, Descriptions of Plant Viruses No. 229, 1980. (3) R. A. C. Jones. Aust. J. Agric. Res. 55:757, 2004.

Heterologous expression and characterization of the exopolysaccharide from Streptococcus thermophilus Sfi39

The genes responsible for exopolysaccharide (EPS) synthesis in Streptococcus thermophilus Sfi39 were identified on a 20-kb genomic fragment. The two genes, epsE and epsG, were shown to be involved in EPS synthesis as their disruption lead to the loss of the ropy phenotype. Several naturally selected nonropy mutants were isolated, one acquired an insertion sequence (IS)-element (IS905) in the middle of the eps gene cluster. The eps gene cluster was cloned and transferred into a nonEPS-producing heterologous host, Lactococcus lactis MG1363. The EPS produced was shown by chemical analysis and NMR spectroscopy to be identical to the EPS produced by S. thermophilus Sfi39. This demonstrated first that all genes needed for EPS production and export were present in the S. thermophilus Sfi39 eps gene cluster, and second that the heterologous production of an EPS was possible by transfer of the complete eps gene cluster alone, provided that the heterologous host possessed all necessary genetic information for precursor synthesis.

Purification and characterisation of a galactoglucomannan from kiwifruit (Actinidia deliciosa)

A galactoglucomannan (GGM) has been purified from the primary cell walls of ripe kiwifruit. A combination of barium hydroxide precipitation, anion exchange- and gel-permeation chromatography gave a chemically homogeneous polymer with a 1:2:2 galactose-glucose-mannose ratio and a molecular weight range of 16-42 kDa. Complete hydrolysis of the polymer with endo-1,4-beta-mannanase (EC 3.2.1.78) from Aspergillus niger gave a mixture of oligosaccharides, three of which (II, III, IV) accounted for more than 80% of the GGM. Structural characterisation of these oligosaccharides and the original polysaccharide was achieved by linkage analysis, 1D and 2D NMR spectrometry and enzymatic hydrolysis. Oligosaccharide II beta-D-Glcp-(1-->4)-beta-D-Manp-(1-->, III beta-D-Glcp-(1-->4)-[alpha-D-Galp-(1-->6)]-beta-D-Manp-(1-->, and IV beta-D-Glcp-(1-->4)-[beta-D-Galp-(1-->2)-alpha-D-Galp-(1-->6)]-beta-D-Manp-(1-->4)-beta-D-Glcp-(1-->4)-beta-D-Manp-(1-->, appeared in the molar ratio of 2:1:1. A trace amount of mannobiose (I) was detected, indicating that some of the mannosyl residues were contiguous. It is concluded that the predominant structural feature of kiwifruit GGM is a backbone of alternating beta-(1-->4)-linked D-glucopyranosyl and D-mannopyranosyl residues, with approximately one third of the latter carrying side-chains at 0-6 of single alpha-D-Galp-(1--> residues (50% of the branches) or the disaccharide beta-D-Galp-(1-->2)-alpha-D-Galp-(1--> (50% of the branches), the substituted residues being separated by three or five unsubstituted monosaccharide units.

Structure and properties of the exopolysaccharide produced by Streptococcus macedonicus Sc136

Streptococcus macedonicus is a Gram positive lactic acid bacterium that is part of the starter flora present in Greek sheep and goat cheeses. The S. macedonicus Sc136 strain produces a high-molecular-mass, highly texturizing exopolysaccharide composed of D-glucose, D-galactose, and N-acetyl-D-glucosamine in the molar ratio of 3:2:1. The structure of the exopolysaccharide produced by S. macedonicus Sc136 was determined by chemical analysis, mass spectrometry, and nuclear magnetic resonance spectroscopy. The repeating unit was shown to be: (see text) The polysaccharide sidechain beta-D-Galf-(1-->6)-beta-D-Glcp-(1-->6)-beta-D-GlcpNAc is a key factor in the highly texturizing properties of the S.macedonicus Sc136 exopolysaccharide. Finally, the trisaccharide sequence beta-D-GlcpNAc-(1-->3)-beta-D-Galp-(1-->4)-beta-D-Glcp corresponds to the internal backbone of the lacto-N-tetraose and lacto-N-neotetraose units, which serve as a structural basis for the large majority of human milk oligosaccharides, an additional property offering an important potential for the development of improved infant nutrition products.

Introduction of the exopolysaccharide gene cluster from Streptococcus thermophilus Sfi6 into Lactococcus lactis MG1363: production and characterization of an altered polysaccharide

Streptococcus thermophilus Sfi6 produces an exopolysaccharide (EPS) composed of glucose, galactose and N-acetylgalactosamine in the molar ratio of 1:2:1. The genes responsible for the EPS biosynthesis have been isolated previously and found to be clustered in a 14.5 kb region encoding 13 genes. Transfer of this gene cluster into a non-EPS-producing heterologous host, Lactococcus lactis MG1363, yielded an EPS with a similar high molecular weight, but a different structure from the EPS from the native host. The structure of the recombinant EPS was determined by means of 1H homonuclear and 1H-13C heteronuclear two-dimensional nuclear magnetic resonance (NMR) spectra and was found to be --> 3)-beta-D-Glcp-(1 --> 3)-alpha-D-Galp-(1 --> 3)-beta-D-Galp-(1 --> as opposed to --> 3)[alpha-D-Galp-(1 --> 6)]-beta-D-Glcp-(1 --> 3)-alpha-D-GalpNAc-(1 --> 3)-beta-D-Galp-(1 --> for the wild-type S. thermophilus Sfi6. Furthermore, L. lactis MG1363 (pFS101) was also lacking a UDP-N-acetylglucosamine C4-epimerase activity, which would provide UDP-GalNAc for a GalNAc incorporation into the EPS and probably caused the substitution of GalNAc by Gal in the recombinant EPS. This modification implies that (i) bacterial glycosyltransferases could potentially have multiple specificities for the donor and the acceptor sugar molecule; and (ii) the repeating unit polymerase can recognize and polymerize a repeating unit that differs in the backbone as well as in the side-chain from its native substrate.

Structure of a Numb PTB domain-peptide complex suggests a basis for diverse binding specificity

The phosphotyrosine-binding (PTB) domain of Numb, a protein involved in asymmetric cell division, has recently been shown to bind to the adapter protein Lnx through an LDNPAY sequence, to the Numb-associated kinase (Nak) through a sequence that does not contain an NPXY motif and to GP(p)Y-containing peptides obtained from library screening. We show here that these diverse peptide sequences bind with comparable affinities to the Numb PTB domain at a common binding site on the surface of the protein. The NMR structure of the Numb PTB domain in complex with a GPpY-containing peptide reveals a novel mechanism of binding with the peptide in a helical turn that does not hydrogen bond to the PTB domain beta-sheet. These results suggest that PTB domains can potentially have multiple modes of peptide recognition and provide a structural basis from which the multiple functions of the Numb PTB domain during asymmetric cell division could arise.

Analytical description of the effect of adiabatic pulses on IS, I2S, and I3S spin systems

An analytical description of the evolution of magnetization in InS spin systems (1 </= n </= 3) during the course of an adiabatic pulse applied on spin S is provided. Calculations show that multiple-quantum terms are created during the pulse and that the rate at which in-phase and antiphase I-spin magnetization components interchange during spin-echo-based pulse sequences is decreased relative to the case where a hard inversion pulse is substituted for the adiabatic pulse. This has important consequences for purging schemes making use of such frequency-swept pulses. Simulations demonstrate that the evolution of in-phase I magnetization is essentially independent of n.

High-affinity binding of the Drosophila Numb phosphotyrosine-binding domain to peptides containing a Gly-Pro-(p)Tyr motif

The phosphotyrosine-binding (PTB) domain is a recently identified protein module that has been characterized as binding to phosphopeptides containing an NPXpY motif (X = any amino acid). We describe here a novel peptide sequence recognized by the PTB domain from Drosophila Numb (dNumb), a protein involved in cell fate determination and asymmetric cell division during the development of the Drosophila nervous system. Using a Tyr-oriented peptide library to screen for ligands, the dNumb PTB domain was found to bind selectively to peptides containing a YIGPYphi motif (phi represents a hydrophobic residue). A synthetic peptide containing this sequence bound specifically to the isolated dNumb PTB domain in solution with a dissociation constant (Kd) of 5.78 +/- 0.74 microM. Interestingly, the affinity of this peptide for the dNumb PTB domain was increased (Kd = 1.41 +/- 0.10 microM) when the second tyrosine in the sequence was phosphorylated. Amino acid substitution studies of the phosphopeptide demonstrated that a core motif of sequence GP(p)Y is required for high-affinity binding to the dNumb PTB domain. Nuclear magnetic resonance experiments performed on isotopically labeled protein complexed with either Tyr- or pTyr-containing peptides suggest that the same set of amino acids in the dNumb PTB domain is involved in binding both phosphorylated and nonphosphorylated forms of the peptide. The in vitro selectivity of the dNumb PTB domain is therefore markedly different from those of the Shc and IRS-1 PTB domains, in that it interacts preferentially with a GP(p)Y motif, rather than NPXpY, and does not absolutely require ligand phosphorylation for binding. Our results suggest that the PTB domain is a versatile protein module, capable of exhibiting varied binding specificities.

The conformation of NAD+ bound to lactate dehydrogenase determined by nuclear magnetic resonance with suppression of spin diffusion

We have reinvestigated the conformation of NAD+ bound to dogfish lactate dehydrogenase (LDH) by using an NMR experiment that allows one to exploit nuclear Overhauser effects to determine internuclear distances between pairs of protons, without perturbation of spin-diffusion effects from other protons belonging either to the cofactor or to the binding pocket of the enzyme. The analysis indicates that the structure of bound NAD+ is in accord with the conformation determined in the solid state by x-ray diffraction for the adenosine moiety, but deviates significantly from that of the nicotinamide. The NMR data indicate conformational averaging about the glycosidic bond of the nicotinamide nucleotide. In view of the strict stereospecificity of catalysis by LDH and the conformational averaging of bound NAD+ that we infer from solution-state NMR, we suggest that LDH binds the cofactor in both syn and anti conformations, but that binding interactions in the syn conformation are not catalytically productive.

Suppression of spin diffusion in selected frequency bands of nuclear Overhauser spectra

A variant of two-dimensional nuclear Overhauser effect spectroscopy (NOESY) is described that yields information about cross-relaxation rates between pairs of spins, while the migration of magnetization through several consecutive steps (spin diffusion via neighboring spins) is largely suppressed. This can be achieved by inserting a doubly-selective inversion pulse in a conventional NOESY sequence.

Geriatric consultation teams in acute hospitals: impact on back-up of elderly patients

Back-up of elderly patients in hospital awaiting long-term placement has become a major problem in some areas of the United States and elsewhere. In 1982, geriatric consultation teams (physician, nurse, and social worker) were introduced into six acute hospitals in Monroe County, New York, to help alleviate the problem through more attention to restoration of patient function and comprehensive discharge planning. Over a six-month period, 4,328 newly hospitalized patients aged 70 or older were screened, and geriatric consultations were provided for 366 (8.5 per cent) who were judged to be at risk of requiring prolonged hospital stays. During this period, the mean monthly census of elderly patients backed up in hospital declined 21 per cent, a reversal of previous rises that could not be explained by any other identifiable factors. The impact was on length of stay on back-up status rather than rate of entry to that status. A variety of medical, rehabilitative, and social interventions accounted for this outcome. A number of health care system barriers to expeditious rehabilitation and discharge of hospitalized elderly patients were identified. Geriatric consultation was deemed useful for implementation in acute hospitals in other settings.