Media and technology usage and attitudes in emergency department patients

Introduction

Digital health technologies are increasingly being used in emergency medicine, many of which utilize smartphones and computers. Patient willingness to use these modalities is an important factor in successful implementation. Therefore, this study aimed to assess emergency department (ED) patients' use of and attitudes towards technology.

Methods

This was a pooled sub-analysis of ED patients (≥18 years old) that were enrolled in two studies evaluating the ED patient experience in response to novel technological interventions. Participants completed the Media and Technology Usage and Attitudes Scale (MTUAS) that assessed computer and smartphone ownership; frequency of use of phone calls, texting, email, and smartphones; and anxiety and dependence attitudes on these technologies.

Results

One hundred and forty-four participants completed the survey. Mean age was 47.2 years (SD 17.94); 61.8% were female; and 61.1% were white. There was high usage of smartphones (93.1%) and computers (74.3%). Participants most frequently used phone calling and texting and least commonly used email. Participants had a positive attitude (mean 3.9/5, SD 0.68) towards the use of these technologies.

Discussion

ED patients reported high ownership of smartphones and computers, had a positive attitude towards their use, and had varying frequency with which they used different technologies. Future studies can use this information to inform the development of digital health interventions that utilize technologies that patients find most acceptable.

Building digital twins of the human immune system: toward a roadmap

Digital twins, customized simulation models pioneered in industry, are beginning to be deployed in medicine and healthcare, with some major successes, for instance in cardiovascular diagnostics and in insulin pump control. Personalized computational models are also assisting in applications ranging from drug development to treatment optimization. More advanced medical digital twins will be essential to making precision medicine a reality. Because the immune system plays an important role in such a wide range of diseases and health conditions, from fighting pathogens to autoimmune disorders, digital twins of the immune system will have an especially high impact. However, their development presents major challenges, stemming from the inherent complexity of the immune system and the difficulty of measuring many aspects of a patient’s immune state in vivo. This perspective outlines a roadmap for meeting these challenges and building a prototype of an immune digital twin. It is structured as a four-stage process that proceeds from a specification of a concrete use case to model constructions, personalization, and continued improvement.

Three-dimensional geometric morphometric analysis of the skull of Protoceratops andrewsi supports a socio-sexual signalling role for the ceratopsian frill

Socio-sexual selection is predicted to be an important driver of evolution, influencing speciation, extinction and adaptation. The fossil record provides a means of testing these predictions, but detecting its signature from morphological data alone is difficult. There are, nonetheless, some specific patterns of growth and variation which are expected of traits under socio-sexual selection. The distinctive parietal-squamosal frill of ceratopsian dinosaurs has previously been suggested as a socio-sexual display trait, but evidence for this has been limited. Here, we perform a whole-skull shape analysis of an unprecedentedly large sample of specimens of Protoceratops andrewsi using a high-density landmark-based geometric morphometric approach to test four predictions regarding a potential socio-sexual signalling role for the frill. Three predictions-low integration with the rest of the skull, significantly higher rate of change in size and shape during ontogeny, and higher morphological variance than other skull regions-are supported. One prediction, sexual dimorphism in shape, is not supported, suggesting that sexual differences in P. andrewsi are likely to be small. Together, these findings are consistent with mutual mate choice or selection for signalling quality in more general social interactions, and support the hypothesis that the frill functioned as a socio-sexual signal in ceratopsian dinosaurs.

3049Equally high detection rates of atrial fibrillation in patients after a TIA and stroke by systematic ECG monitoring with an implanted device: SPIDER-AF study

Introduction

The risk of neurovascular and cardiovascular morbidity is substantially increased by undetected atrial fibrillation (AF). Therefore, early detection of AF is crucial to initiate appropriate therapy in persons at risk and may improve outcome. An implantable loop recorder (ILR) can monitor the heart rhythm for up to three years, modern devices provide dedicated algorithms to detect AF.

Hypothesis

We aimed to investigate the AF detection rate by the use of an ILR in patients after a recent cerebrovascular event (TIA n=137 or stroke n=363) presenting in sinus rhythm and no history of AF in the ambulatory setting by office based cardiologists.

Purpose

Observational study in patients with no prior diagnosis of AF, who had (presumably thromboembolic) transient ischemic attack (TIA) or stroke within 12 months and were implanted an ILR in the last 6 months. Follow-up visits every 3 months for 1 year overall.

Results

In 34 outpatient cardiology centers in Germany, a total of 500 patients were documented (mean age 63.1±12.7 years, 35.4% >70 years; 60.8% males). The qualifying event - diagnosed by neurologists - was a TIA in 137 (27.4%) and a stroke in 363 (72.6%) with typical thromboembolic pattern in NMR imaging (29.2% TIA/45.2% stroke, p<0.001), in CT imaging (7.3% TIA/7.7% stroke, n.s.), in both (6.6% TIA/19.6% stroke, p<0.001).

During follow-up, AF was newly detected by the device in TIA patients in 29.9% and in stroke patients in 25.6% (n.s.). The mean screening period until detection of AF with the Reveal LinQ device was 170±134 days in TIA, 145±128 in stroke respectively (n.s.). 95.7% had paroxysmal and 4.3% persistent AF in stroke, TIA patients had 100% paroxysmal AF (n.s.), median duration was 5.0 min in TIA and 5.2 min in stroke, respectively (n.s.). Most AF patients were asymptomatic (68.3% TIA/ 83.9% stroke, p<0.03).

The mean CHA2DS2Vasc score in patients with AF was 4.0 and 4.1 in those with TIA and stroke (n.s.), for patients in sinus rhythm 3.7 and 3.9, respectively (n.s.). Arterial hypertension was present in 71.5% with TIA/76.0% with stroke (n.s.), diabetes mellitus in 15.3% with TIA/25.1% with stroke (p<0.05), coronary artery disease in 12.4% with TIA/14.6% with stroke (n.s.), vascular disease in 3.6% with TIA/5.0% with stroke (n.s.).

Conclusions

In patients in sinus rhythm and no history of AF after a TIA or stroke, during 1-year follow-up AF could be newly detected in a quarter of patients by means of systematic continuous screening with an implantable ECG device. As AF diagnosis usually leads to immediate secondary prevention with long-term anticoagulation, such screening is useful not only in stroke but also in TIA patients and may substantially reduce the risk of recurrent stroke and cardiovascular morbidity.

Acknowledgement/Funding

SPIDER-AF registry was performed by BNK Service GmbH, Munich (Germany) and supported by Bayer Vital GmbH and Medtronic GmbH in equal parts

Konzentration des C-reaktiven Proteins (CRP) im Blutserum bei Hunden mit postoperativen Wundheilungsstörungen

Gegenstand und Ziel: Ziel dieser Studie war die Beurteilung des perioperativen Verlaufs der Konzentration des kaninen C-reaktiven Proteins (CRP) im Blutserum bei komplikationsloser Wundheilung und bei postoperativen Wundheilungsstörungen. Material und Methoden: Entsprechend dem postoperativen Verlauf der Wundheilung wurden 99 Hunde in folgende Gruppen eingeteilt: komplikationslose Wundheilung (Kontrollgruppe, n = 57), Wundinfektion (n = 11), Nahtdehiszenz (n = 5), Serom (n = 6), Hämatom (n = 7), passagerer Reizzustand (n = 12) und sonstige Komplikationen (n = 1). Ergebnisse: Patienten mit komplikations-loser Wundheilung zeigten klinisch im postoperativen Verlauf eine stetige Abschwächung der initialen lokalen Entzündungsreaktion. Auch die CRP-Konzentration war durch einen initialen Gipfel und einen sich anschließenden stetigen Abfall charakterisiert. Bei Patienten, deren Wundheilung durch eine fortbestehende oder wiederaufflammende Entzündung charakterisiert war, ergaben sich postoperativ fast immer unverändert hohe CRP-Konzentrationen oder ein deutlicher Wiederanstieg sowie höhere CRP-Konzentrationen als bei den Kontrolltieren. Dies konnte nicht nur bei Patienten mit klinisch sichtbarer Wundinfektion oder Nahtdehiszenz nachgeweisen werden, sondern auch bei Patienten ohne eindeutige klinische Anzei-chen einer Nahtdehiszenz oder Wundinfektion (passagerer Reizzustand). Demgegenüber zeigten Patienten mit Serom oder Hämatom im weiteren postoperativen Verlauf weder klinisch eine ausgeprägte Entzündungsreaktion noch erhöhte CRP-Konzentrationen. Schlussfolgerung: Die serielle Bestimmung der CRPKonzentration stellt einen objektiven Parameter zur Beurteilung der Wundheilung dar. Klinische Relevanz: Unverändert hohe oder deutlich wiederansteigende CRP-Konzentrationen sind, unter Beachtung bestimmter Voraussetzungen, eine Indikation, weitere diagnostische Maßnahmen einzuleiten und therapeutische Gegenmaßnahmen zu ergreifen.

Biogas purification with biomass ash

The aim of the study was to investigate the option to purify biogas from small-scale biogas plants by entrapping CO₂ and H₂S with regionally available biomass ash. Connected to the existing biogas plant Neustift (Tyrol) wood ash placed in a 1 m³ container was used as a trap for CO₂ and H₂S in the biogas. With the process conditions chosen, for a period of a few hours CO₂ was trapped resulting in pure methane. The removal of H₂S was much longer-lasting (up to 34 d). The cumulative H₂S uptake by the biomass ash ranged from 0.56 to 1.25 kg H₂S per ton of ash. The pH of the ash and the leachability of Lead and Barium were reduced by the flushing with biogas, however toxicity towards plants was increased thus reducing the potential of ash use in agriculture. It can be concluded that biomass ash may be used for removal of hydrogen sulphide from biogas in small and medium biogas plants. The economic evaluation, however, indicated that the application of this system is limited by transport distances for the ash and its potential use afterwards.

Antiviral RNA silencing suppression activity of Tomato spotted wilt virus NSs protein

In addition to regulating gene expression, RNA silencing is an essential antiviral defense system in plants. Triggered by double-stranded RNA, silencing results in degradation or translational repression of target transcripts. Viruses are inducers and targets of RNA silencing. To condition susceptibility, most plant viruses encode silencing suppressors that interfere with this process, such as the Tomato spotted wilt virus (TSWV) NSs protein. The mechanism by which NSs suppresses RNA silencing and its role in viral infection and movement remain to be determined. We cloned NSs from the Hawaii isolate of TSWV and using two independent assays show for the first time that this protein restored pathogenicity and supported the formation of local infection foci by suppressor-deficient Turnip mosaic virus and Turnip crinkle virus. Demonstrating the suppression of RNA silencing directed against heterologous viruses establishes the foundation to determine the means used by NSs to block this antiviral process.

Carotid artery ultrasonographic assessment in patients from the Fremantle Diabetes Study Phase II with carotid bruits detected by electronic auscultation

BACKGROUND

Electronic auscultation appears superior to acoustic auscultation for identifying hemodynamic abnormalities. The aim of this study was to determine whether carotid bruits detected by electronic stethoscope in patients with diabetes are associated with stenoses and increased carotid intima-medial thickness (CIMT).

SUBJECTS AND METHODS

Fifty Fremantle Diabetes Study patients (mean±SD age, 73.7±10.0 years; 38.0% males) with a bruit found by electronic auscultation and 50 age- and sex-matched patients with normal carotid sounds were studied. The degree of stenosis and CIMT were assessed from duplex ultrasonography.

RESULTS

Patients with a bruit were more likely to have stenosis of ≥50% and CIMT of >1.0 mm than those without (odds ratios [95% confidence intervals]=14.0 [1.8-106.5] and 5.3 [1.8-15.3], respectively; both P=0.001). For the six patients with stenosis of ≥70%, five had a bruit, and one (with a known total occlusion) did not (odds ratio=5.0 [0.6-42.8]; P=0.22). The sensitivity and specificity of carotid bruit for stenoses of ≥50% were 88% and 58%, respectively; respective values for stenoses of ≥70% were 83% and 52%. The equivalent negative predictive values were 96% and 98%, and positive predictive values were 30% and 10%, respectively.

CONCLUSIONS

Electronic recording of carotid sounds for later interpretation is convenient and reliable. Most patients with stenoses had an overlying bruit. Most bruits were false positives, but ultrasonography is justified to document extent of disease; CIMT measurement will identify increased vascular risk in most of these patients. The absence of a bruit was rarely a false-negative finding, suggesting that these patients can usually be reassured that they do not have hemodynamically important stenosis.

Effect of continuous positive airway pressure therapy on sexual function and serum testosterone in males with type 2 diabetes and obstructive sleep apnoea

OBJECTIVE

There have been no studies of the effect of continuous positive airway pressure (CPAP) therapy on erectile dysfunction (ED) and serum testosterone in men with type 2 diabetes and obstructive sleep apnoea (OSA), a patient group at increased risk of ED and hypogonadism. The aim of this study was to determine whether CPAP improves sexual and gonadal function in males with type 2 diabetes and a pre-CPAP apnoea-hypopnoea index >15/h.

DESIGN

Substudy of a trial assessing the effect of 3 months of CPAP on cardiovascular risk in type 2 diabetes.

PATIENTS

Of 35 males starting CPAP, 27 (mean ± SD age 65.4 ± 9.6 years, median [interquartile range] diabetes duration 12.1 [5.2-15.3] years) completed the trial.

MEASUREMENTS

Serum total and free testosterone, responses to the Androgen Deficiency in the Aging Aale (ADAM) and Sexual Health Inventory for Men (SHIM) questionnaires.

RESULTS

There were no significant changes in mean total or free testosterone (baseline concentrations 12.7 ± 4.5 nm and 0.26 ± 0.07 pm, respectively), or SHIM score (baseline 13 [5-17]), after 3 months of CPAP (P > 0.20). The ADAM score (baseline 6.2 ± 2.1) fell after 1 month (to 5.0 ± 2.6) and was maintained at this level at 3 months (P = 0.015). The Epworth Sleepiness Scale score decreased and self-reported physical activity increased over 3 months (P ≤ 0.017) without a change in body mass index (P = 1.00).

CONCLUSIONS

These findings imply that CPAP therapy improves somnolence and promotes exercise in men with type 2 diabetes, but that there is no direct benefit for gonadal or sexual function.

[Sleeve gastrectomy as a revision procedure for failed gastric banding]

The number of bariatric surgical procedures is still increasing in Germany and also worldwide. According to the German quality assurance study of surgical treatment of obesity, the laparoscopic adjustable gastric banding (LAGB) was the most common bariatric operation with a total of 678 cases between 2004 and 2006 in Germany. In the meantime a high rate of LAGB treatment failures has been reported, so that a high rate of revisional bariatric operations is required. But still the question is open which bariatric procedure can be recommended. The aim of this study is to report the results and follow-up of conversion of failed LAGB to laparoscopic sleeve gastrectomy (LSG). Between 8/2008 and 4/2012 39 patients (31♀/8♂) with a mean age of 43.7 ± 7.8 (26-61) years and a BMI of 47.1 ± 9.1 (30.4 to 67.4) kg/m² had revisional surgery for converting a failed LAGB to LSG. The indications for conversion were dysphagia (38.5 %), weight regain (33.3 %), band slippage (17.9 %), band erosion (5.1 %), band defect (2.6 %) as well as band sepsis (2.6 %). 19 procedures were performed as a one-stage operation and 20 procedures as a two-stage operation. The average operating time was 129 ± 49 (50-312) min. The complication rate was 7.7 %. There were one proximal leak, one gastric sleeve stenosis and one pronounced wound infection. The percent excess weight loss was 23 %, 39 %, 51 %, 52 %, 60 % and 46 % after 1, 3, 6, 12, 24 and 36 months follow- up, respectively. Converting a failed LAGB into a LSG is a revision procedure with low complication rate and promising results, which can be performed as a two-stage as well as a one-stage procedure.

The MAPK-dependent regulation of the Jagged/Notch gene expression by VEGF, bFGF or PPAR gamma mediated angiogenesis in HUVEC

The Jagged-Notch signalling, plays a crucial role in cell differentiation. Angiogenesis, is regulated by VEGF, bFGF as well as by the free fatty acid metabolites , which are regulators of transcription factors such as peroxisome proliferation activating receptors (PPARs). The study analyzed the signalling pathways involved in the regulation of Jagged-1/Notch-4 expression in endothelial cells (HUVECs) in response to VEGF, bFGF and PPAR-gamma exogenous activator - ciglitazone. HUVECs were incubated with investigated substances for 24 hours, with or without the presence of the MAP-kinases inhibitors were used. Jagged-1 and Notch-4 gene expression was determined using quantitative Real-Time PCR. The Jagged-1/Notch-4 protein expression was compared by flow cytometry, when the phosphorylation-dependent activation of kinases was estimated by Western-blot method. The opposite effect of VEGF, bFGF, or ciglitazone on the Jagged-1/Notch-4 expression on HUVEC was connected with the different activation of MAPKs. Ciglitazone, activated p38 MAPK pathway and simultaneously inhibited phosphorylation of p42/44 MAPK. The pro-angiogenic: bFGF and VEGF, also activated the p38 MAPK, but they did not attenuate the p42/44 MAPK phosphorylation. Maintaining of the Jagged/Notch interactions by VEGF, when down-regulation by bFGF and ciglitazone, seems to be dependent on the different effect on p38 MAPK and p42/44 MAPK pathway regulation.

Differentiation of human adipose tissue SVF cells into cardiomyocytes

Progenitor cells have been extensively studied and therapeutically applied in tissue reconstructive therapy. Stromal vascular fraction (SVF) cells, which are derived from adipose tissue, may represent a potential source of the cells which undergo phenotypical differentiation into many lineages both in vitro as well as in vivo. The goal of this study was to check whether human SVF cells may differentiate into cardiomyocyte-like entities. Human SVF cells were induced to differentiate by their incubation in Methocult medium in the presence of SCF, IL-3 and IL-6. Morphological transformation of the cells was monitored using optical light microscope, whereas changes in expression of the genes typical for cardiac phenotype were measured by qRT-PCR. Incubation of the human SVF cells in the medium that promotes cardiomyocyte differentiation in vitro resulted in formation of myotubule-like structures accompanied by up-regulation of the myocardium-characteristic genes, such as GATA, MEF2C, MYOD1, but not ANP. Human SVF cells differentiate into cardiomyocyte-like cells in the presence of the certain set of myogenesis promoting cytokines.

Model generation by domain refinement and rule reduction

The granularity and interpretability of a fuzzy model are influenced by the method used to construct the rule base. Models obtained by a heuristic assessment of the underlying system are generally highly granular with interpretable rules, while models algorithmically generated from an analysis of training data consist of a large number of rules with small granularity. This paper presents a method for increasing the granularity of rules while satisfying a prescribed precision bound on the training data. The model is generated by a two-stage process. The first step iteratively refines the partitions of the input domains until a rule base is generated that satisfies the precision bound. In this step, the antecedents of the rules are obtained from decomposable partitions of the input domains and the consequents are generated using proximity techniques. A greedy merging algorithm is then applied to increase the granularity of the rules while preserving the precision bound. To enhance the representational capabilities of a rule and reduce the number of rules required, the rules constructed by the merging procedure have multi-dimensional antecedents. A model defined with rules of this form incorporates advantageous features of both clustering and proximity methods for rule generation. Experimental results demonstrate the ability of the algorithm to reduce the number of rules in a fuzzy model with both precise and imprecise training information.

Experimental observation of interatomic coulombic decay in neon dimers

Recently Cederbaum et al. [Phys. Rev. Lett. 79, 4778 (1997)]] predicted a new decay channel of excited atoms and molecules termed interatomic Coulombic decay (ICD). In ICD the deexcitation energy is transferred via virtual photon exchange to a neighboring atom, which releases it by electron emission. We report on an experimental observation of ICD in 2s ionized neon dimers. The process is unambiguously identified by detecting the energy of two Ne1+ fragments and the ICD electron in coincidence, yielding a clean, background free experimental spectral distribution of the ICD electrons.

Mechanisms of photo double ionization of helium by 530 eV photons

We have measured fully differential cross sections for photo double ionization of helium 450 eV above the threshold. We have found an extremely asymmetric energy sharing between the photoelectrons and an angular asymmetry parameter beta approximately 2 and beta approximately 0 for the fast and slow electrons, respectively. The electron angular distributions show a dominance of the shakeoff for 2 eV electrons and clear evidence of an inelastic electron-electron scattering at an electron energy of 30 eV. The data are in excellent agreement with convergent close-coupling calculations.

Circular dichroism in K-shell ionization from fixed-in-space CO and N2 molecules

We have measured the angular distributions of 1s photoelectrons excited by circularly and linearly polarized light from fixed-in-space CO and N2 molecules, in the vicinity of their shape resonances. A strong circular dichroism, i.e., a strong dependence on the sense of rotation of the polarization vector of the photons, is found for both molecules. State-of-the-art one-electron multiple scattering and partially correlated random phase approximation calculations are in good agreement with many, but not all, aspects of the experimental data.

The primary sequence of rhesus monkey rhadinovirus isolate 26-95: sequence similarities to Kaposi's sarcoma-associated herpesvirus and rhesus monkey rhadinovirus isolate 17577

The primary sequence of the long unique region L-DNA (L for low GC) of rhesus monkey rhadinovirus (RRV) isolate 26-95 was determined. The L-DNA consists of 130,733 bp that contain 84 open reading frames (ORFs). The overall organization of the RRV26-95 genome was found to be very similar to that of human Kaposi sarcoma-associated herpesvirus (KSHV). BLAST search analysis revealed that in almost all cases RRV26-95 coding sequences have a greater degree of similarity to corresponding KSHV sequences than to other herpesviruses. All of the ORFs present in KSHV have at least one homologue in RRV26-95 except K3 and K5 (bovine herpesvirus-4 immediate-early protein homologues), K7 (nut-1), and K12 (Kaposin). RRV26-95 contains one MIP-1 and eight interferon regulatory factor (vIRF) homologues compared to three MIP-1 and four vIRF homologues in KSHV. All homologues are correspondingly located in KSHV and RRV with the exception of dihydrofolate reductase (DHFR). DHFR is correspondingly located near the left end of the genome in RRV26-95 and herpesvirus saimiri (HVS), but in KSHV the DHFR gene is displaced 16,069 nucleotides in a rightward direction in the genome. DHFR is also unusual in that the RRV26-95 DHFR more closely resembles HVS DHFR (74% similarity) than KSHV DHFR (55% similarity). Of the 84 ORFs in RRV26-95, 83 contain sequences similar to the recently determined sequences of the independent RRV isolate 17577. RRV26-95 and RRV17577 sequences differ in that ORF 67.5 sequences contained in RRV26-95 were not found in RRV17577. In addition, ORF 4 is significantly shorter in RRV26-95 than was reported for RRV17577 (395 versus 645 amino acids). Only four of the corresponding ORFs between RRV26-95 and RRV17577 exhibited less than 95% sequence identity: glycoproteins H and L, uracil DNA glucosidase, and a tegument protein (ORF 67). Both RRV26-95 and RRV17577 have unique ORFs between positions 21444 to 21752 and 110910 to 114899 in a rightward direction and from positions 116524 to 111082 in a leftward direction that are not found in KSHV. Our analysis indicates that RRV26-95 and RRV17577 are clearly independent isolates of the same virus species and that both are closely related in structural organization and overall sequence to KSHV. The availability of detailed sequence information, the ability to grow RRV lytically in cell culture, and the ability to infect monkeys experimentally with RRV will facilitate the construction of mutant strains of virus for evaluating the contribution of individual genes to biological properties.

Building communities that create health

Typically, public health policy, program design, and resource allocation are based on issue-specific, targeted interventions directed at specific populations or sub-populations. The authors argue that this approach fails to meet the goal of public health-to improve health for all--and that the key to health improvement is to create a social context in which healthy choices are the norm. The authors present as case studies two Pennsylvania cities that used multisectoral approaches to achieve community health improvements.

Amitriptyline increases GABA-stimulated 36Cl- influx by recombinant (alpha 1 gamma 2) GABAA receptors

WSS-1 cells expressing (alpha 1 gamma 2)GABAA receptors show an augmented 36Cl- response to GABA in the presence of amitriptyline that is increased by flumazenil, unlike augmentation by diazepam which is blocked by flumazenil. This amitriptyline effect is opposite to the inhibition of GABA-stimulated 36Cl influx manifested in membrane vesicles prepared from drug-naive rats or submissive rats (a model of depression) but is similar to that seen in tissue from amitriptyline-treated rats or dominant rats. The results suggest a novel mechanism of antidepressant drug action having a delayed onset.

Variability in leaf optical properties among 26 species from a broad range of habitats

Leaves from 26 species with growth forms from annual herbs to trees were collected from open, intermediate, and shaded understory habitats in Mississippi and Kansas, USA. Leaf optical properties including reflectance, transmittance, and absorptance in visible and near infrared (NIR) wavelengths were measured along with leaf thickness and specific leaf mass (SLM). These leaf properties and internal light scattering have been reported to vary with light availability in studies that have focused on a limited number of species. Our objective was to determine whether these patterns in leaf optics and light availability were consistent when a greater number of species were evaluated. Leaf thickness and SLM varied by tenfold among species sampled, but within-habitat variance was high. Although there was a strong trend toward thicker leaves in open habitats, only SLM was significantly greater in open vs. understory habitats. In contrast, leaf optical properties were strikingly similar among habitats. Reflectance and reflectance/transmittance in the NIR were used to estimate internal light scattering and there were strong relationships (r1 &gt; 0.65) between these optical properties and leaf thickness. We concluded that leaf thickness, which did not vary consistently among habitats, was the best predictor of NIR reflectance and internal light scattering. However, because carbon allocation to leaves was lower in understory species (low SLM) yet gross optical properties were similar among all habitats, the energy investment by shade leaves required to achieve optical equivalence with sun leaves was lower. Differences in leaf longevity and growth form within a habitat may help explain the lack of consistent patterns in leaf optics as the number of species sampled increases.

Results of therapeutic penetrating keratoplasty

PURPOSE

To determine the anatomic and visual results of therapeutic penetrating keratoplasty (PK) and its role in the management of corneal disease.

METHODS

The authors reviewed the records of all of their patients who had undergone therapeutic PK over the past 9 years and evaluated each for the following criteria: cure of disease, graft clarity, and visual acuity. Patients were divided into seven categories: (1 and 2) bacterial and fungal keratitis, (3 and 4) herpetic keratitis, with and without inflammation, (5) acanthamoebic keratitis, (6) perforations due to keratoconjunctivitis sicca, and (7) other causes of perforation.

RESULTS

In microbial keratitis, therapeutic PK eradicated the disease in all cases. Seventy-three percent of grafts for bacterial keratitis and 60% for fungal keratitis remained clear. A higher percentage of clarity was achieved when grafts were 9.0 mm or less. Seven patients with secondary endophthalmitis were cured with a surgical approach including therapeutic PK. In herpetic keratitis with active inflammation, only 36% of grafts remained clear, and inflammation recurred in 36%. All perforations due to post-herpetic persistent epithelial defects in "quiet" eyes were grafted successfully. In patients with severe keratoconjunctivitis sicca, eyes were anatomically stabilized in 83%, but all grafts failed because of complications from ocular surface disease.

CONCLUSIONS

Therapeutic PK is valuable in the management of microbial keratitis that does not respond to antimicrobial therapy. Results are poorer for patients with herpetic keratitis, although selected patients respond to therapeutic PK when other methods of management have failed. Patients with perforations due to keratoconjunctivitis sicca have a uniformly poor prognosis for graft clarity.

Hirudisins. Hirudin-derived thrombin inhibitors with disintegrin activity

Recombinant hirudin variants have been designed which inhibit alpha-thrombin by the hirudin mechanism and which in addition exhibit disintegrin activity. These proteins, called "hirudisins," have been engineered by replacing the Ser-Asp-Gly-Glu sequence at the tip of hirudin's finger-like structure (residues 32-35) by Arg-Gly-Asp-Ser (RGDS) to yield hirudisin and Lys-Gly-Asp-Ser (KGDS) to obtain hirudisin-1. Comparison of thrombin inhibition activities showed that hirudisin is 2-fold more potent (K(i) = 160 +/- 70 fM) than hirudisin-1 (K(i) = 370 +/- 44 fM) and recombinant (r)-hirudin (K(i) = 270 +/- 50 fM). alpha-Thrombin-stimulated platelet aggregation was effectively inhibited by r-hirudin, hirudisin, and hirudisin-1 with IC50 of 5.7 to 6.8 nM. Unlike r-hirudin, hirudisin inhibits ADP-induced platelet aggregation (IC50 = 65 microM) 3- to 5-fold stronger than the linear GRGDS- and RGDS-peptide. Direct interaction of hirudisin with purified glycoprotein IIb-IIIa demonstrated that antiplatelet aggregation activity is due to the integrin-directed RGD motif. Disintegrin activity of hirudisin relative to that of reduced and carboxymethylated hirudisin suggests that the conformational strain favors binding to integrins. On the basis of these results, hirudisins appear to be interesting molecules for the design of potential antithrombotic agents with antithrombin as well as antiplatelet aggregation activities.

[Studies of tryptophan metabolism in cancer of the urinary bladder]

In 100 patients suffering from urinary bladder cancer (pTA-4, Nx, M0-1, G0-3) we created an oral tryptophan load administering 5 g of L-type tryptophan. Thereafter the amount of both xanthurenic acid and kynurenin was determined quantitatively in the 24-hour urine. 16 patients revealed pathological test results and excretion pattern of tryptophan metabolites via kynurenin were similar to vitamin B6-dependent xanthurenic aciduria both in its homocygotic and heterocygotic pattern. It has not been possible to prove a direct correlation between xanthurenic aciduria and urinary bladder cancer. However, xanthurenic aciduria may be of significance as a risk factor in the etiopathogenesis of urinary bladder cancer.

Nutrition and oral health in the elderly

At every age, an adequate supply of nutrients is necessary to maintain optimal oral health. This article presents an overview of various factors that have an impact on the nutritional status of the elderly, current recommendations regarding nutrient requirements of this age group, as well as a discussion of nutrients that may be marginal in diet of elderly persons. Suggestions for assessing nutritional status in a dental practice are offered.

[Studies on tryptophan metabolism in calcium oxalate urolithiasis]

In 90 patients with calcium oxalate urolithiasis an oral tryptophan-loading test with 5 g L-tryptophan was performed and the 24-hour urinary excretion of xanthurenic acid and kynurenine was measured. In 10 cases pathological deviations and an excretion pattern of tryptophan metabolites via kynurenine similar as in the hereditary vitamin-B6-dependent xanthurenic aciduria in homozygous or heterozygous from were found. Correlations between the oxalate excretion and the tryptophan metabolism do not exist. A 2-year therapy with 60 mg vitamin B6 was favourable in patients with an excretion of more than 300 mumol XA after a tryptophan load.

Corneal amyloidosis associated with keratoconus

Nodular, gray-white, central corneal opacities which extended from the subepithelial zone through the anterior four fifths of the stroma developed in a 50-year-old man with a longstanding history of hard contact lens wear for keratoconus. Results of histopathologic analysis of the corneal button obtained at the time of penetrating keratoplasty disclosed that the opacities were composed of amyloid. Corneal amyloidosis is rarely found in association with keratoconus. Although there were some similarities in the pattern of amyloid deposition to that seen in primary familial amyloidosis of the cornea, the authors believe that their patient is more likely to have had a secondary amyloidosis. Corneal amyloidosis should be considered in keratoconus patients with development of unusual forms of central corneal opacification.

Serious corneal complications of glaucoma filtering surgery with postoperative 5-fluorouracil

We studied four patients who, having received postoperative 5-fluorouracil after glaucoma filtering operations, developed serious corneal complications. All four patients had preexisting corneal abnormalities including keratoconjunctivitis sicca, exposure keratopathy, and bullous keratopathy. All of the patients developed epithelial defects in the postoperative period. The complications included bacterial corneal ulceration (two patients), sterile corneal ulceration and corneal perforation (one patient), and a keratinized corneal plaque with underlying sterile stromal infiltrate (one patient). The use of 5-fluorouracil, which is an antimetabolite with considerable corneal epithelial toxicity, after glaucoma filtering surgery frequently causes corneal epithelial defects that may lead to secondary complications. Patients receiving this drug should have their corneal status closely monitored. In patients with corneal epithelial disease, 5-fluorouracil should be used with caution.

Mycobacterium avium-intracellulare corneal ulcer

A healthy 28-year-old man developed a slowly progressive corneal ulcer 21 months after an episode of corneal trauma. Acid-fast bacilli were identified in corneal scrapings, and the causative organism was identified as Mycobacterium avium-intracellulare. Medical treatment with topical amikacin and oral rifampin was ineffective, and a therapeutic penetrating keratoplasty was necessary to cure the infection. To the best of our knowledge, this is only the second reported case of a corneal infection caused by a slow-growing nontuberculous mycobacterium (Runyon groups I, II, and III) and the first caused by M. avium-intracellulare. Slowly growing nontuberculous mycobacteria should be considered among those organisms that cause corneal infection, especially in cases characterized by a protracted course and lack of response to conventional antimicrobial therapy.

Reversion of bovine papillomavirus-induced transformation and immortalization by a xanthate compound

Bovine papilloma virus-transformed hamster embryo fibroblasts (HEF-BPV) reacted to exposure to tricyclodecan-9-yl-xanthogenate (D609) with immediate reversion to the growth kinetics and the flat morphology of the untransformed parental cells. After six population doublings in the presence of D609, clones which displayed an untransformed morphology in the absence of D609 arose with a high frequency (90%). Such clones had reacquired a limited in vitro lifetime and had lost the ability to induce tumors in athymic nude mice. At the molecular level the revertant clones had lost all extrachromosomal monomeric BPV-1 DNA molecules. Only high molecular weight (HMW) oligomeric BPV-1 DNA that was probably integrated into the cellular genome was still detectable in a methylated transcriptionally inactive state. In contrast to transformed cells, the revertant clones no longer transcribed BPV-1-specific mRNA molecules, but were stimulated by a tumor promoter to transient viral gene expression. This article provides direct evidence for the complete reversibility of the property of "immortality".

[Urologic complications following radiotherapy of cancers of the corpus uteri]

Patients with endometrial carcinomas who have undergone only radiation therapy represent a negative selection, because of the many concomitant diseases. In the author's group of 134 cases such patients were on average 7 years older than those who had undergone surgery. Even with computer-calculated opposing-field therapy with intracavity packing, radiation damage to the urinary tract must be expected. Of the 134 patients, 75 (55.9%) had pathologic urological findings following radiation therapy. The most commonly affected organ was the bladder (55.2%), followed by the kidneys (21.6%) and the ureter (7.5%). Radiation damage to the urethra could not be verified. The urological complications were hardly affected by the stage of the tumor, but considerably so by the time interval: the rate of urological complications was 68.9% higher after 5 years than after 1 year. Therefore, accurate statements concerning urological complications following primary radiation therapy for endometrial carcinoma cannot be made until 5 years have elapsed.

DNA and RNA virus species are inhibited by xanthates, a class of antiviral compounds with unique properties

Various DNA and RNA virus species are inhibited by xanthate compounds at concentrations that leave the mitotic activity of uninfected cells unimpaired. The concentration of tricyclodecan -9-yl- xanthogenate that reduces the yield of herpes simplex virus types 1 and 2 by 50% is between 4.5 and 33 microM. The replication of DNA viruses such as simian virus 40 can be blocked at the DNA and RNA level both early and late after infection. The xanthates are not incorporated into nucleic acids. Episomal bovine papilloma virus DNA replication and transcription are also inhibited in transformed cells. The treated cells revert to the normal phenotype by acquisition of contact inhibition and a flat morphology.