Interventions to promote health literacy among working-age populations experiencing socioeconomic disadvantage: systematic review

Background

Experiencing financial insecurity and being underserved is often associated with low health literacy, i.e., the ability to identify, obtain, interpret and act upon health information, which may result in poor health outcomes. Little is known about effective interventions for promoting health literacy among underserved populations. The objective of this systematic review is to summarize the literature on such interventions and identify characteristics that differentiate more effective interventions.

Methods

Following PRISMA guidelines we searched the databases SCOPUS, Pubmed, Web of Science core collection and CINAHL. We included primary studies with a quantitative study design and control groups testing interventions to increase health literacy or health knowledge in underserved populations between 18 and 65 years. Where possible, we converted effect sizes into Cohen's d and compared mean differences of intervention and control groups. Albatross plots were created to summarize the results according to different health literacy and health knowledge outcomes.

Results

We screened 3,696 titles and abstracts and 206 full texts. In total, 86 articles were analyzed, of which 55 were summarized in seven albatross plots. The majority of the studies (n = 55) were conducted in the United States and had a randomized controlled study design (n = 44). More effective intervention approaches assessed needs of participants through focus group discussions prior to conducting the intervention, used bilingual educational materials, and included professionals fluent in the first languages of the study population as intervention deliverers. Additionally, the use of educational materials in video and text form, fotonovelas and interactive group education sessions with role playing exercises were observed to be effective.

Discussion

Although the outcomes addressed in the included studies were heterogeneous, effective intervention approaches were often culturally sensitive and developed tailored educational materials. Interventions aiming to promote health literacy in underserved populations should hence consider applying similar approaches.Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=323801, PROSPERO registration ID: CRD42022323801.

Assessing the contribution of migration related policies to equity in access to healthcare in European countries. A multilevel analysis

Access to good healthcare and the conditions for good health is one of the central dimensions of immigrant integration. National health policies play a major role in equipping residents with the necessary entitlements to accessible and acceptable healthcare services. Rarely analysed so far is the contribution of migration-related health policies to equity in access to healthcare between immigrants and the general population. To address this gap, this study analysed whether the extent to which migration is considered within national health policies moderates the association between immigration status and subjectively perceived unmet medical need in Europe. Using data from the 2019 European Union Statistics on Income and Living Conditions (EU-SILC) survey in combination with the Migration Integration Policy Index (MIPEX) a multilevel analysis was carried out assessing the cross-level interaction between immigration status and MIPEX scores controlling for individual-level factors such as age, gender, education and employment status. While our results showed that immigrants are more likely to report unmet medical need than the general population (adjusted Odds Ratio (aOR) = 1.32; 95% confidence interval (CI) 1.22-1.43), the cross-level interaction indicated increased relative inequality in unmet medical need between immigrants and the general population in countries with high MIPEX scores compared to countries with low MIPEX scores (aOR = 1.39, 95% CI: 1.18-1.63). The main reason for this increase of inequality on the relative scale was the overall lower prevalence of unmet medical need in countries with high MIPEX scores. In conclusion, our findings indicate that even in countries with relatively migration-friendly health policies inequalities in access to healthcare between immigrants and the general population persist.

Experimental and Theoretical Study of the Ultrafast Dynamics of a Ni2 Dy2 -Compound in DMF After UV/Vis Photoexcitation

We present a combined experimental and theoretical study of the ultrafast transient absorption spectroscopy results of a {Ni₂Dy₂}‐compound in DMF, which can be considered as a prototypic molecule for single molecule magnets. We apply state‐of‐the‐art ab initio quantum chemistry to quantitatively describe the optical properties of an inorganic complex system comprising ten atoms to form the chromophoric unit, which is further stabilized by surrounding ligands. Two different basis sets are used for the calculations to specifically identify two dominant peaks in the ground state. Furthermore, we theoretically propagate the compound's correlated many‐body wavefunction under the influence of a laser pulse as well as relaxation processes and compare against the time‐resolved absorption spectra. The experimental data can be described with a time constant of several hundreds of femtoseconds attributed to vibrational relaxation and trapping into states localized within the band gap. A second time constant is ascribed to the excited state while trap states show lifetimes on a longer timescale. The theoretical propagation is performed with the density‐matrix formalism and the Lindblad superoperator, which couples the system to a thermal bath, allowing us to extract relaxation times from first principles.

Topological Spin-Charge Gearbox on a Real Molecular Magnet

In this work, using ab initio many-body theory and inspired by an idea suggested by G. D. Mahan for an abstract N-dimensional chain composed of s-type atoms ( Phys. Rev. Lett. 2009, 102, 016801), we propose a functional topological spin-charge gearbox based on the real synthesized Co₃Ni(EtOH) cluster driven with laser pulses. We analyze the implications arising from the use of a real molecule with d-character functional orbitals rather than an extended system and discuss the role of the point group symmetry of the system and the transferability of the electronic and spin density between different many-body states using specially designed laser pulses. We thus find that first-row transition-metal elements can host unpaired yet correlated d electrons and thus act as sites for spin information carriers, while designated laser pulses induce symmetry operations leading to a realizable spin-charge gearbox.

[Urinary incontinence in men]

Stress urinary incontinence in men is predominantly iatrogenic whereby radical prostatectomy is the most common cause with persistent stress urinary incontinence rates varying between 10 % and 25 %. The first line therapy for postoperative male stress urinary incontinence is physiotherapy, especially pelvic floor muscle rehabilitation. If conservative treatment fails to show sufficient improvement, surgical therapy is recommended. Several treatment options are currently available for the surgical treatment of male stress urinary incontinence including artificial sphincters, adjustable and functional sling systems, bulking agents and implantable balloon systems.

Der Einfluß von Sauerstoff- und Wasserdampfzusätzen auf die lonenbeweglichkeit und Elektronen-Anlagerungswahrscheinlichkeit in Stickstoff

In einer mit Stickstoff (1 atm) gefüllten Ionisationskammer werden durch RÖNTGEN-Strahlenimpulse Impulse von positiven und negativen Ladungsträgern erzeugt, die oszillographiert werden. Dem Stickstoff wird Sauerstoff (bis 2,5 Vol.-Proz.) und/oder Wasserdampf (bis 2,3 Vol.-Proz.) zugesetzt. Aus den Oszillogrammen werden die Ionenbeweglichkeiten und Elektronenanlagerungswahrscheinlichkeiten ermittelt. Die Beweglichkeiten werden durch Wasserdampfbeimengungen stark herabgesetzt. Die Elektronenanlagerungswahrscheinlichkeit nimmt mit dem Sauerstoffgehalt zu. In Stickstoff mit 2,3 Vol.-Proz. Wasserdampf ist sie jedoch rund 10-mal größer als in trockenem Stickstoff. Wasserdampf allein scheint in Stickstoff keine Elektronen anzulagern.

Combined theoretical and experimental study of spin and charge dynamics on the homodinuclear complex [Ni2(II)(L-N4Me2)(emb)]

We present a combined theoretical and experimental study of spin and charge dynamics on the homodinuclear compound [Ni2(II)(L-N4Me2)(emb)]. The theoretically calculated oscillator strengths of the ground-state absorption spectrum show an acceptable agreement with experiment. We predict a local ultrafast laser-induced spin-flip scenario, which involves charge-transfer states. Experimentally, we observe charge dynamics on two different time scales. The two relevant, transient electronic states and their electronic properties are also theoretically characterized. These results provide a joint investigation of the homodinuclear complex and suggest a realistic scenario for ultrafast spin dynamics and other optical-related manipulations.

Angular momentum conservation for coherently manipulated spin polarization in photoexcited NiO: an ab initio calculation

In an ultrafast laser-induced magnetization-dynamics scenario we demonstrate for the first time an exact microscopic spin-switch mechanism. Combining ab initio electronic many-body theory and quantum optics analysis we show in detail how the coherently induced material polarization for every elementary process leads to angular-momentum exchange between the light and the irradiated antiferromagnetic NiO. Thus we answer the long-standing question where the angular momentum goes. The calculation also predicts a dynamic Kerr effect, which provides a signature for monitoring spin dynamics, by simply measuring the transient rotation and ellipticity of the reflected light.

Decay of hybridized electronic states of a Na cluster on Cu(001)

The electronic properties of a Na9+ cluster are markedly changed when deposited on a Cu(001) surface. Particularly, the lifetime of the (hybridized) single-particle electronic states are drastically enhanced indicating a change in electronic correlations upon absorption. To capture this effect, we developed a Green's function approach based on the configuration interaction technique. The calculated lifetimes (16.5 to 33 fs) of excited electronic states are in line with experimental observations. Our new method demonstrates the feasibility of accounting accurately for electronic correlation in large, nonperiodic systems.

Ab initio treatment of optical second harmonic generation in NiO

In this Letter we develop a new systematic approach to study optical second harmonic generation in NiO, on both the (001) surface and the bulk. NiO is modeled as a doubly embedded cluster on which two highly correlated quantum chemistry methods are applied in order to obtain the wave functions of all the intragap d states and the low lying charge transfer states. The optical gap is calculated and the electric dipole, magnetic dipole, and electric quadrupole contributions to the second order susceptibility tensor are computed for the first time from first principles. Going beyond the electric dipole approximation gives new insight into the experimentally observed spectrum. A method is proposed for monitoring the spin dynamics of the NiO(001) surface.

The influence of X-ray radiation on the mineral/organic matrix interaction of bone tissue: an FT-IR microscopic investigation

Fourier transform infrared microscopy was used to investigate human cortical bone samples before and after treatment with increasing doses of X-ray radiation. Especially the spectral region of the v1 and v3 phosphate vibrations of hydroxyapatite, the main mineral component of bone, and the region of the amide I and amide II vibrational bands due to the collagen extracellular matrix were examined. Major spectral changes in the phosphate region between 1250-1000 cm(-1) occur after irradiation doses between 1 and 4 Gray. These findings are explained by a decrease in size of mineral crystallites and by variances of the toichiometric/non-stoichiometric apatite composition. The Ca2+ /PO4(3-) /HPO4(2-) composition in the biological apatite is altered near the bone surface. The secondary structure of the collagen matrix is not affected by cumulative irradiation up to doses of 15 Gray as indicated by the unchanged frequency maximum and contour shape of the amide I band between 1600-1700 cm(-1) . However, side chain carboxylate groups of the collagen matrix that are involved in coordination with apatite bound calcium ions are partially removed by decarboxylation upon irradiation. Concomitantly, a loss of acidic phosphate groups due to a formation of phosphate groups with bound calcium is observed. These changes on a molecular level can be correlated with alterations in the mechanical properties of the bone samples, e.g. with an increased embrittlement as deduced from experiments with a scanning acoustic microscope.

All-optical subpicosecond magnetic switching in NiO(001)

Combining optical control theory with ab initio quantum chemistry and electronic crystal field theory we explore the laser induced femtosecond spin dynamics. We propose a scenario for ultrafast all-optical magnetic switching that results from the combination of spin-orbit coupling with appropriately shaped short laser pulses. We find that the application of the theory to the multiplet states within the gap of NiO(001) predicts for the first time the possibility of all-optical spin switching within 100 fs. The switching can be observed using any of the multiplets as the intermediate state.

The yeast nucleoporin Nup53p specifically interacts with Nic96p and is directly involved in nuclear protein import

The bidirectional nucleocytoplasmic transport of macromolecules is mediated by the nuclear pore complex (NPC) which, in yeast, is composed of approximately 30 different proteins (nucleoporins). Pre-embedding immunogold-electron microscopy revealed that Nic96p, an essential yeast nucleoporin, is located about the cytoplasmic and the nuclear periphery of the central channel, and near or at the distal ring of the yeast NPC. Genetic approaches further implicated Nic96p in nuclear protein import. To more specifically explore the potential role of Nic96p in nuclear protein import, we performed a two-hybrid screen with NIC96 as the bait against a yeast genomic library to identify transport factors and/or nucleoporins involved in nuclear protein import interacting with Nic96p. By doing so, we identified the yeast nucleoporin Nup53p, which also exhibits multiple locations within the yeast NPC and colocalizes with Nic96p in all its locations. Whereas Nup53p is directly involved in NLS-mediated protein import by its interaction with the yeast nuclear import receptor Kap95p, it appears not to participate in NES-dependent nuclear export.

Human pre-mRNA cleavage factor II(m) contains homologs of yeast proteins and bridges two other cleavage factors

Six different protein factors are required in vitro for 3' end formation of mammalian pre-mRNAs by endonucleolytic cleavage and polyadenylation. Five of the factors have been purified and most of their components cloned, but cleavage factor II(m) (CF II(m)) remained uncharacterized. We have purified CF II(m) from HeLa cell nuclear extract by several chromatographic steps. During purification, CF II(m) activity separated into two components, one essential (CF IIA(m)) and one stimulatory (CF IIB(m)) for the cleavage reaction. CF IIA(m) fractions contain the human homologs of two yeast 3' end processing factors, Pcf11p and Clp1p, as well as cleavage factor I(m) (CF I(m)) and several splicing and transcription factors. We report the cloning of hClp1 and show that it is a genuine subunit of CF IIA(m). Antibodies directed against hClp1 deplete cleavage activity, but not polyadenylation activity from HeLa cell nuclear extract. hClp1 interacts with CF I(m) and the cleavage and polyadenylation specificity factor CPSF, suggesting that it bridges these two 3' end processing factors within the cleavage complex.

Laser-induced ultrafast demagnetization in ferromagnetic metals

The laser-induced femtosecond demagnetization in ferromagnetic metals is investigated theoretically. Different from the conventional nanosecond one, this ultrafast demagnetization is a cooperative effect of the external laser field and the internal spin-orbit coupling. The spin-orbit coupling smears out the original identities of triplets and singlets while the laser field uses it as an avenue to influence demagnetization. Importantly, this demagnetization can be manipulated controllably, an essential point to future applications, such as ultrafast control of magneto-optical gating. Finally, the polarization filter effect on the ultrafast time scale is discussed based upon the present theoretical results.

A Fourier transform infrared spectroscopic study of the interaction of alkaline earth cations with the negatively charged phospholipid 1, 2-dimyristoyl-sn-glycero-3-phosphoglycerol

The interaction of aqueous phospholipid dispersions of negatively charged 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol, sodium salt (DMPG) with the divalent cations Mg(2+), Ca(2+) and Sr(2+) at equimolar ratios in 100 mM NaCl at pH 7 was investigated by Fourier transform infrared spectroscopy. The binding of the three cations induces a crystalline-like gel phase with highly ordered and rigid all-trans acyl chains. These features are observed after storage below room temperature for 24 h. When the gel phase is heated after prolonged incubation at low temperature phase transitions into the liquid crystalline phase are observed at 58 degrees C for the DMPG:Sr(2+), 65 degrees C for the DMPG:Mg(2+), and 80 degrees C for the DMPG:Ca(2+) complex. By subsequent cooling from temperatures above T(m) these complexes retain the features of a liquid crystalline phase with disordered acyl chains until a metastable gel phase is formed at temperatures between 38 and 32 degrees C. This phase is characterized by predominantly all-trans acyl chains, arranged in a loosely packed hexagonal or distorted hexagonal subcell lattice. Reheating the DMPG:Sr(2+) samples after a storage time of 2 h at 4 degrees C results in the transition of the metastable gel to the liquid crystalline phase at 35 degrees C. This phase transition into the liquid crystalline state at 35 degrees C is also observed for the Mg(2+) complex. However, for DMPG:Mg(2+) at higher temperatures, a partial recrystallization of the acyl chains occurs and the high temperature phase transition at 65 degrees C is also detected. In contrast, DMPG:Ca(2+) exhibits only the phase transition at 80 degrees C from the crystalline gel into the fluid state upon reheating. Below 20 degrees C, the rate of conversion from the metastable gel to a thermodynamically stable, crystalline-like gel phase decreases in the order Ca(2+)&z. Gt;Mg(2+)>Sr(2+). This conversion into the crystalline gel phase is accompanied by a complete dehydration of the phosphate groups in DMPG:Mg(2+) and by a reorientation of the polar lipid head groups in DMPG:Ca(2+) and in DMPG:Sr(2+). The primary binding sites of the cations are the PO(2)(-) groups of the phosphodiester moiety. Our infrared spectroscopic results suggest a deep penetration of the divalent cations into the polar head group region of DMPG bilayers, whereby the ester carbonyl groups, located in the interfacial region of the bilayers, are indirectly affected by strong hydrogen bonding of immobilized water molecules. In the liquid crystalline phase, the interaction of all three cations with DMPG is weak, but still observable in the infrared spectra of the DMPG:Ca(2+) complex by a slight ordering effect induced in the acyl chains, when compared to pure DMPG liposomes.

Interactions between coiled-coil proteins: Drosophila lamin Dm0 binds to the bicaudal-D protein

In a yeast two-hybrid screen we identified an interaction between Drosophila lamin Dm0, a structural nuclear protein, and BICD, a protein involved in oocyte development. The interaction can be reconstituted in vitro and takes place between segments of both proteins predicted to form coiled coils. The affinity for lamin Dm0 of the minimal binding site on BICD is modulated in a complex fashion by other BICD segments. A point mutation, F684I, that causes the dominant, bicaudal, Bic-D phenotype inhibits lamin binding in the context of the minimal lamin-binding site, but not in a larger BICD fragment. The minimal lamin-binding site of BICD binds to a few other coiled-coil proteins, but binding to these proteins is not influenced by the F684I point mutation, suggesting that the interaction with lamin may play a role in Bic-D function. Our structural studies demonstrated that BICD is 60-70% alpha-helical, is a dimer, and consists of two parts: a thin rod-shaped part of about 32 nm, and a thicker rod-shaped part of about 26 nm. Likely, the thinner rod-shaped part of full-length BICD consists of the N-terminal half of the protein, and the lamin-binding site is located within the thicker rod-shaped part.

A new UHV angle encoder for high-resolution synchrotron radiation monochromators

The high precision of 0.1 arcsec required for the positioning of optical elements in new two-axes monochromators at the undulator beamlines at BESSY II has led to the development of UHV-compatible high-precision angle encoders. Mounted directly on the rotation axes, they provide substantial advantages over measuring systems connected outside the vacuum vessel. Making use of a fast closed-loop control system, an accuracy of 0.1 arcsec at a resolution of less than 0.01 arcsec has been experimentally verified.

Infrared absorbances of protein side chains

The spectral parameters of amino acid residue side chain and peptide bond absorptions in the region 1800-1440 cm-1 have been obtained by using an inverse matrix method applied to the infrared spectra of 42 amino acids, dipeptides, and higher peptides in aqueous solution. In addition the pH-dependent extinction coefficients of the amino acid and peptide COO-/NH3+ end groups were derived. It is shown that the secondary structure prediction accuracy of proteins by multivariate data analysis methods increases slightly, if the side chain absorbances of the residues asparagine, glutamine, aspartic acid, glutamic acid, arginine, tyrosine, and lysine are subtracted from the amide I and amide II region.

10 years of cooperation with the Department of Experimental Surgery, University Medical School of Debrecen: scientific outcome and impact on clinical practice

From 1986-1996 several series of experiments were done in cooperation with the Department of Experimental Surgery, University Medical School of Debrecen. Very interesting scientific findings have been achieved in the fields of urethral surgery, continent urinary diversion, alternatives to dialysis, laparoscopy and bladder stimulation. Besides representing a high scientific output nearly all experiments had direct impact on our clinical practice.

Phase correction in Fourier transform spectroscopy: subsequent displacement correction and error limit

In Fourier transform spectroscopy interferograms are apodized prior to the transformation and the calculated spectrum is phase corrected. If the zero point for the Fourier transformation is displaced, a phase error occurs because the apodization remains fixed while the interferogram is shifted by the phase correction. A theoretical description of this effect is derived and an algorithm for subsequent removal is provided. It is also reported that fixing the zero point to solely the sampling positions leads to error in the band shape that by far exceeds the noise and therefore limits the spectroscopic accuracy.

The 30-kD subunit of mammalian cleavage and polyadenylation specificity factor and its yeast homolog are RNA-binding zinc finger proteins

Cleavage and polyadenylation specificity factor (CPSF), a key component of the mammalian RNA 3'-end processing machinery, consists of four subunits of 160, 100, 73, and 30 kD. Here we report the isolation and characterization of a cDNA encoding the 30-kD polypeptide. Antibodies raised against this protein inhibit cleavage and polyadenylation and coimmunoprecipitate the other CPSF subunits. The protein sequence contains five C3H-zinc-finger repeats and a putative RNA-binding zinc knuckle motif at the carboxyl terminus. Consistent with this observation, the in vitro translated 30-kD protein binds RNA polymers with a distinct preference for poly(U). In addition, an essential S. cerevisiae gene, YTH1, was cloned which is 40% identical to CPSF 30K at the protein level. Extracts prepared from a conditional yth1 mutant have normal cleavage activity, but fail to polyadenylate the upstream cleavage product. Efficient polyadenylation activity can be restored by the addition of purified polyadenylation factor I (PF I). We demonstrate that Yth1p is a component of PF I that interacts in vivo and in vitro with Fip1p, a known PF I subunit.

Secondary structure determination of proteins in aqueous solution by infrared spectroscopy: a comparison of multivariate data analysis methods

The accuracy of the secondary structure prediction from an infrared spectra data base of 39 proteins with known X-ray structure was investigated by different methods of multivariate data analysis. The best agreements with the secondary structure determined by X-ray crystallography are obtained if both the amide I and amide II bands are used for calibration. With optimized parameters the methods singular value decomposition, partial least squares, and ridge regression yield similar results. As judged by the standard error of prediction, the secondary structure elements helix and beta-sheet can be predicted with the highest accuracy. Small data sets of less than 20 protein spectra, which exhibit the variance in secondary structure content of the whole set, can pretend an increased prediction accuracy only if column cross-validation is used as reference; however, with these calibration sets the average secondary structure prediction of all 39 proteins is debased. The hydrogen-bonded turns or bridges are predicted with higher accuracy than the assigned secondary structure types helix and beta-sheet.

A correlation between thermal stability and structural features of staphylokinase and selected mutants: a Fourier-transform infrared study

Variants of recombinant staphylokinase (Sak) were investigated by Fourier-transform infrared spectroscopy: Sak (wild type), Sak-M26A, Sak-M26L, and Sak-G34S/R36G/R43H (Sak-B). Estimation of the secondary structure and hydrogen-deuterium exchange experiments revealed the existence of fast-exchanging and strongly solvent-exposed fractions of the helical structures in the two samples Sak and Sak-M26L. These two samples are also thermally less stable with unfolding transition temperatures of 43.7 degrees C (Sak) and 43.5 degrees C (Sak-M26L), respectively. On contrast, Sak-M26A and Sak-G34S/R36G/R43H have a slower hydrogen-deuterium exchange, have a smaller solvent-exposed portion of the helical part, and are more resistant against thermal unfolding; the transition temperatures are 51.7 degrees C and 59.3 degrees C, respectively. The secondary structure analysis was performed by two different approaches, by curve-fitting after band narrowing and by pattern recognition (factor analysis) based upon reference spectra of proteins with known crystal structure. Within the limits of the used methods, we are unable to detect significant differences in the secondary structure of the four variants of Sak. According to the results of the factor analysis, the portions of secondary structure elements were obtained to 16-20% alpha-helix, 28-30% beta-sheet, 23-27% turns, 28-30% irregular (random) and other structure. The sharp differences in the specific plasminogen-activating capacity (Sak, Sak-G34S/R36G/R43H and Sak-M26L are fully active, but Sak-M26A does not form a stable complex with plasminogen) are not reflected in the structural features revealed by the infrared spectra of this study.

Secondary structure and stability of the bacterial carbohydrate-specific recognition proteins K88ab, AFA-1, NFA-1, and CFA-1

The conformation and thermodynamic stability of the four polymeric carbohydrate-specific bacterial recognition proteins K88ab, AFA-1, NFA-1, and CFA-1 and their monomeric subunits that can be obtained by variation of pH were studied by infrared spectroscopy and differential scanning microcalorimetry. For NFA-1, a pH-dependent dissociation of the polymeric form cannot be achieved due to the stronger interactions of the neighboring subunits. Generally, no alterations in secondary structure are observed between the monomeric and the polymeric proteins. All adhesins reveal a high degree of beta-sheet structure (40-55%), while the alpha-helix component is of minor importance (10-20%). The adhesins investigated in this study revealed unusually high denaturation temperatures (69-104 degrees C) and stabilizing Gibbs energies, delta G (40-125 kJ/mol), compared to common globular proteins. Statistical deconvolution of the DSC curves yields a two-state transition of K88ab, NFA-1, and the monomeric CFA-1 and the existence of intermediate states for AFA-1 and polymeric CFA-1 during the denaturation process. The irreversible denaturation of K88ab, AFA-1, and CFA-1 is explained by aggregation of the polypeptide chains forming a three-dimensional network of intermolecular beta-sheet-type structures. In contrast, denaturation of NFA-1 is completely reversible. At a physiologically relevant temperature of approximately 40 degrees C, we observe predenaturational events in the DSC curves of polymeric K88ab and NFA-1 with no concomittant changes in the secondary structure of these proteins.