Cryosectioning-enabled super-resolution microscopy for studying nuclear architecture at the single protein level

DNA-PAINT combined with total Internal Reflection Fluorescence (TIRF) microscopy enables the highest localization precisions, down to single nanometers in thin biological samples, due to TIRF's unique method for optical sectioning and attaining high contrast. However, most cellular targets elude the accessible TIRF range close to the cover glass and thus require alternative imaging conditions, affecting resolution and image quality. Here, we address this limitation by applying ultrathin physical cryosectioning in combination with DNA-PAINT. With "tomographic & kinetically-enhanced" DNA-PAINT (tokPAINT), we demonstrate the imaging of nuclear proteins with sub-3 nanometer localization precision, advancing the quantitative study of nuclear organization within fixed cells and mouse tissues at the level of single antibodies. We believe that ultrathin sectioning combined with the versatility and multiplexing capabilities of DNA-PAINT will be a powerful addition to the toolbox of quantitative DNA-based super-resolution microscopy in intracellular structural analyses of proteins, RNA and DNA in situ.

The effect of pre-ESRD care program on potentially inappropriate medication in advanced CKD patients

Background

Due to the multiple comorbidities and the associated complications among advanced CKD population, assessing potentially inappropriate medications (PIM) in these patients is an important task for physicians and multidisciplinary care team members. This study aimed to investigate the impact of the national pre-ESRD pay-for-performance (P4P) program on prescribing quality in Taiwan.

Methods

We conducted a retrospective cohort study using data from National Health Insurance Research Database (NHIRD) maintained by the Health and Welfare Data Science Center, Ministry of Health and Welfare (HWDC, MOHW). The incidents of CKD in year 2010 were observed until the end of 2017. Adult patients who initiated maintenance dialysis therapy were enrolled. To identify the use of PIM that should be avoided in advanced CKD patients, the Beers 2019 criteria and latest Taiwan Manual of Renal Injury Prevention and Drug Safety were applied. We measured PIM use in one year before starting long-term dialysis.

Results

Among 7,828 participants underwent continuous dialysis treatment, 2,119 (27.1%) were P4P patients. Most (90.4%) participants were prescribed one or more PIMs before ESRD initiation. After adjusted age, sex, Charlson Comorbidity Index (CCI) and the number of nephrologist visits, the logistic regression showed lower probability of PIM use in the P4P enrollees (OR = 0.56, 95% CI = 0.47-0.66). The effect of P4P on PIM was more prominent in the subgroups of patients who were female and CCI≤3.

Conclusions

The implementation of the pre-ESRD P4P program might reduce PIM use among CKD patients. Our results underline the strategy of financial incentives in the payment design to improve prescribing patterns.

Key messages

Prescribing potentially inappropriate medications is common among patients who were approaching ESRD. The study highlights the importance of implementing the pre-ESRD P4P program to reduce PIM use in advanced CKD patients.

P2602Inhaled iloprost improves echocardiographic myocardial performance during exercise in heart failure with preserved ejection fraction

Introduction

The pathophysiology of HFpEF is complicated and treatments that improve outcomes in HFrEF have no substantial benefits in HFpEF. Impairments in LV global longitudinal strain (GLS) and LV diastolic function parameters have been regarded as novel echocardiographic markers to predict cardiovascular events in HFpEF. Preliminary trials indicate that iloprost, an inhaled prostacyclin analougue, improves exercise hemodynamics in both patients with pulmonary artery hypertension and pulmonary hypertension associated with HFpEF.

Purpose

We aim to investigate the impact of inhaled iloprost on LV global longitudinal strain, LV diastolic function and RV function during exercise in HFpEF population.

Methods

34 patients diagnosed with HFpEF were included with exclusion of severe pulmonary, coronary artery, valvular heart and pericardial diseases. Subjects were randomized 1:1 to inhalation of iloprost or placebo. Transthoracic echocardiography was performed at rest and after 6-minute supine bicycle exercise at 20-Watt workload. We utilized tissue speckle tracking by QLAB software to derive LV GLS and global strain rate during LV isovolumetric relaxation period (SRIVR). E/e', E/SRIVR, tricuspid regurgitation pressure gradient (TRPG), tissue Doppler imaging of RV lateral tricuspid annulus and tricuspid annular plane systolic excursion (TAPSE) were measured to evaluate changes of myocardial performance.

Results

LV GLS during exercise significantly enhanced after iloprost use. E/SRIVR, a novel predictor of LV filling pressure, was significantly decreased. E/e' was also lower in iloprost group by trend. Improvements in RV function and degree of pulmonary hypertension during exercise with iloprost were observed in this study.

Echocardiographic myocardial function endpoints during 20-Watt excercise between iloprost and placebo groups Iloprost (N=17) Placebo (N=17) P value LV global longitudinal strain, % −4.96±1.20 −0.75±3.00 <0.001 E/SRIVR, cm 206.41±113.55 454.13±262.98 0.005 E/e' mean 10.77±2.39 14.41±12.14 0.235 TAPSE, cm 2.62±0.62 2.37±0.56 0.221 TRPG, mmHg 28.37±12.47 44.25±9.29 <0.001 TDI lateral tricuspid annulus, cm/s 16.41±4.61 14.77±2.92 0.222

Effects of iloprost at rest and exercise

Conclusions

Our study is the first to demonstrate that, in patients with HFpEF, inhaled iloprost favorably enhances LV GLS reserves, decreases LV diastolic filling load, reduces pulmonary hypertension and thereby improves RV function during exercise.

Acknowledgement/Funding

This work was supported in part by the National Science Council of the Republic of China, Taiwan (NSC107-2314-B-002-265-MY3)

P1880Entropy-based algorithm for atrial fibrillation detection using photoplethysomgraphic signal recorded by a smart watch

Background

Atrial fibrillation (AF) is the most common arrhythmia, and its paroxysmal and short duration nature makes its detection challenging. The most important limitation of current smartwatches is that patients need to touch to the sensor of the watch to record signals when patients feel discomfort. We developed a wearable smart watch and evaluated its accuracy to differentiate AF from sinus rhythm, which can continuously detecting heart rhythm without hand touching the device.

Methods and results

A wearable smart watch with PPG sensor and electrocardiogram (ECG) recording function was used for signal acquisition. A total 399 patients with a mean age of 67 years old were enrolled in the study, of whom 237 (81.5%) were male, and 101 have been diagnosed with AF. Pulse wave extracted from the green light spectrum of the signal and ECG were recorded for about 10 minutes for each patient. Pulse-to-pulse intervals (PPI) were automatically identified. All ECG signals were verified by two cardiologists. The correlation between R-to-R interval on ECG and PPI were excellent, with a correlation coefficient R >0.99 (p<0.05). An entropy-based algorithm which combined Shannon entropy of successive difference of PPI and sample entropy of PPI was used to discriminate between AF and sinus rhythm. This method had high sensitivity and specificity (96% and 98%, respectively), the area under receiver operating characteristic curve reached 0.98.

Conclusions

We developed an entropy-based algorithm for AF detection with PPG signal recorded by a wearable smart watch. This algorithm discriminates AF from sinus rhythm accurately. This advance in technology overcomes an important clinical obstacle and can increase the AF detection rate tremendously.

P1604Validating previously reported Brugada syndrome-associated common variants identified in caucasian population in the Han Chinese BrS cohort in Taiwan: SADS-BrS registry

Background

Brugada syndrome (BrS) is a sudden arrhythmic death. The prevalence of BrS is higher in the Southeast Asian populations than that in Caucasian patients. A previous genome-wide association study (GWAS) has reported 13 SNPs significantly associated with BrS. However, no study was performed to validate whether these SNPs are enriched in BrS patients in Han Chinese (HC).

Purpose

Evaluating the common variants previously reported in Caucasian BrS patients could be generalized to HC BrS patients in Taiwan

Methods

We genotyped 200 unrelated BrS patients using Affymetrix TWB Array (N=653,291 SNPs, a customized array for HC in Taiwan). The controls are obtained from the Taiwan Biobank (N ≈ 16,000) using the same array. An imputation workflow was shown in Figure 1. To confirm the accuracy of the imputed genotype of each variant, Sanger sequencing was performed in 10% of randomly selected cases.

Results

Among the 3 most important common variants (rs11708996 in SCN5A, rs10428132 in SCN10A and rs9388451 in HEY2/NCOA7) reported in the previous GWAS mainly conducted in Caucasian BrS patients, 2 of them (rs10428132 and rs9388451) were successfully replicated in the HC population in Taiwan (P<0.01). We also found that the differences of minor allele frequency (dMAF: the MAF of cases minus the MAF of controls) of the two variants were relatively smaller between the BrS cases and healthy controls in HC population compared with that in Caucasian populations (dMAF, rs9388451: 0.15 (Caucasian) vs −0.07 (HC); rs10428132: 0.28 (Caucasian) vs 0.11 (HC)). For the remaining 10 common variants reaching genome-wide significance (P=5×10–8) in Caucasian BrS patients, 9 of them were also significantly enriched in the HC BrS patients after the Bonferroni correction (P<0.05/12=0.0042). We next analyzed the variants identified in the previous GWAS on ECG traits (PR interval, QRS duration, QTc interval, and heart rate) in the Caucasian population. Among the reported 75 variants associated with ECG traits, 5 common variants (rs6798015 (PR), rs1760876 (QRS), rs6795970 (PR/QRS), rs2074238 (QTc) and rs314370 (heart rate)) were significant after Bonferroni correction (P<0.05/75=0.00066).

Figure 1

Conclusions

The preliminary results indicated that 85% of common variants of SCN10A and HEY2/NCOA7 previously reported in Caucasian BrS patients are replicated in BrS patients in the HC population but not the common variant of SCN5A (rs11708996). Furthermore, the common variants of SCN10A and HEY2/NCOA7 related to cardiac depolarization or repolarization may also contribute to the development of BrS.

Acknowledgement/Funding

NTUH 106-S3469, NTUH106-S3458 and NTUH 106-018

[Comparison the clinical efficacy of 3D versus 2D total laparoscopic thyroidectomy for thyroid cancer by via-breast approach]

Objective:To summarize and analyze the clinical efficacy of 3D and 2D laparoscopic surgery in thyroidectomy for thyroid cancer. Method: Thirty-seven patients with early-differentiated thyroid cancer underwent laparoscopic surgery from August 2016 to November 2018. Their clinical data were retrospectively analyzed. They were divided into 3D laparoscopic group and 2D laparoscopic group based on laparoscopic imaging systems. The perioperative clinical indicators and postoperative complications of the two groups were compared. Result: Compared with the 2D laparoscopic group, the 3D laparoscopic group had shorter operation time and less bleeding, and the incidence of postoperative complications was less, but the differences between the two groups were not statistically significant(P>0.05). Conclusion: Compared with the 2D laparoscopic thyroidectomy, 3D laparoscopic thyroidectomy for thyroid cancer allows higher surgical precision, shorter operation time, lower operation risk and smoother surgical procedure, thus improves surgical efficiency.

UV treatments on the physicochemical properties of tilapia skin and pig skin gelatin

Tilapia skin gelatin, pig skin gelatin, and their mousse premixes were exposed to UV irradiation for 103, 206, and 309 kJ/cm2. All samples after 309 kJ/cm2 exposure exhibited a significant increase in gel strength, gel forming ability as well as viscosity of solutions. It was shown that UV treatment could also improve the pig skin gelatin foam stability and foam formation ability compared to those of tilapia skin gelatin. Nevertheless, the panelists gave the lowest scores to mousse made with 309 kJ/cm2 UV-irradiated premix mousse pig skin gelatin. Tilapia skin gelatin could be used as a substitute ingredient for premix mousse made from pig skin gelatin.

Diagnosis of hyperlipidemia and treatment with a statin in the outpatient stroke clinic

The aim of this study was to assess a stroke clinic's performance in the diagnosis of hyperlipidemia and more specifically to evaluate the effectiveness of statins in patients with cerebrovascular disease not enrolled in a research study. The records of 370 consecutive patients seen at a stroke clinic over a 4-year period were reviewed, and information regarding neurologic diagnosis, lipid profile, and use and type of cholesterol-lowering medication was abstracted. Hyperlipidemia was defined as a total cholesterol level equal to or more than 200 mg/dL. Forty-eight patients meeting specific criteria were further analyzed to monitor the effects of statins. Cholesterol testing was obtained in 324 patients (88%) and 178 (55%) were hyperlipidemic, but only 86 (48%) patients received treatment. The mean cholesterol level of the 48 patients dropped from 246.2 mg/dL to 197.1 mg/dL (P < .0001) after the initiation of statin therapy, and significant reductions were present in subgroups with pretreatment levels of 200 to 249 mg/dL and 250 to 299 mg/dL. Of the 21 patients with repeated cholesterol testing more than 6 months after the first posttreatment test, only 11 (52%) maintained a level below 200 mg/dL. Effective control of hyperlipidemia can be achieved in patients with cerebrovascular disease, but not all are adequately tested or treated. Improved physician awareness and more effective health care delivery systems are needed.

Crystals of ligand-free bovine neurophysin II

A modified neurophysin, des 1-6 bovine neurophysin II, has been crystallized in the absence of bound hormone or hormone analogue. These crystals represent the first crystals of ligand-free neurophysin, and are essential for understanding neurophysin-hormone recognition as well as hormone-induced neurophysin dimerization. The crystals diffract to beyond 1.8 A resolution, belong to space group P3(1)21 (or P3(2)21) with a = 48.86, c = 78.61 A, and contain one molecule per asymmetric unit.

Structures of an unliganded neurophysin and its vasopressin complex: implications for binding and allosteric mechanisms

The structures of des 1-6 bovine neurophysin-II in the unliganded state and as its complex with lysine vasopressin were determined crystallographically at resolutions of 2.4 A and 2.3 A, respectively. The structure of the protein component of the vasopressin complex was, with some local differences, similar to that determined earlier of the full-length protein complexed with oxytocin, but relatively large differences, probably intrinsic to the hormones, were observed between the structures of bound oxytocin and bound vasopressin at Gln 4. The structure of the unliganded protein is the first structure of an unliganded neurophysin. Comparison with the liganded state indicated significant binding-induced conformational changes that were the largest in the loop region comprising residues 50-58 and in the 7-10 region. A subtle binding-induced tightening of the subunit interface of the dimer also was shown, consistent with a role for interface changes in neurophysin allosteric mechanism, but one that is probably not predominant. Interface changes are suggested to be communicated from the binding site through the strands of beta-sheet that connect these two regions, in part with mediation by Gly 23. Comparison of unliganded and liganded states additionally reveals that the binding site for the hormone alpha-amino group is largely preformed and accessible in the unliganded state, suggesting that it represents the initial site of hormone protein recognition. The potential molecular basis for its thermodynamic contribution to binding is discussed.

Risperidone augmentation of specific serotonin reuptake inhibitors in the treatment of refractory obsessive-compulsive disorder: report of two cases

The efficacy of specific serotonin reuptake inhibitors (SSRI) in the treatment of obsessive-compulsive disorder (OCD) has been established, but more than 40% of patients continue to have a poor response to SSRI. Low-dose antipsychotic augmentation of SSRI has contributed to the amelioration of symptoms in the treatment of refractory obsessive-compulsive disorder patients. Due to the risk of side effects from traditional antipsychotics, atypical novel antipsychotic augmentation of SSRI may be a good choice in the treatment of refractory obsessive-compulsive disorder. Herein we report our experience with two OCD patients, one with a poor response to fluoxetine 80 mg per day for 3 months, and the other with poor response to fluoxetine 60 mg per day for 3 months. Both OCD patients also proved to have a poor response to paroxetine 60 mg per day for 6 weeks. Neither patient had received any psychotherapy or behavioral therapy. Both patients showed significant improvement in their obsessive-compulsive symptoms as measured by the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), after risperidone 1 mg per day was added to their on-going use of paroxetine 60 mg per day. Within 4 weeks of adding risperidone, the two patients' Y-BOCS scores had decreased by 57% and 53%. This result suggests that risperidone augmentation of SSRI may be a good choice and an effective treatment strategy for refractory OCD.

Selective cell loss in Edinger-Westphal in asymptomatic elders and Alzheimer's patients

Exaggerated pupillary response to a low concentration of cholinergic antagonists has been suggested as an early marker for Alzheimer's Disease (AD). To examine the anatomic basis of this phenomenon, we determined possible neuropathological changes in the Edinger-Westphal (EW) nucleus, a midbrain neural center with a significant functional role in the control of pupil size. Stereologically determined neuronal numbers within the EW were counted in individuals with pathologically confirmed AD, control cases with no AD-type pathology, and subjects with AD pathology not meeting diagnostic criteria for AD. The EW of AD patients displayed a marked and striking neuronal loss when compared with controls. In contrast, the number of neurons in the somatic portion of the nucleus of the third cranial nerve (NCNIII) remained intact. The EW in brains from clinically normal individuals with evidence of early AD-type pathology also displayed a significant and selective loss of neurons. The magnitude of EW neuronal loss in the latter group was smaller than that observed in AD. These findings suggest that pupillary hypersensitivity in AD may be caused by abnormalities in the EW. Neuronal loss and pathology within the EW in a subpopulation of clinically silent controls with pathologic findings consistent with early-stage AD constitutes a possible explanation for the reported exaggerated pupil response in some normal elderly subjects.

Human ferrochelatase: characterization of substrate-iron binding and proton-abstracting residues

The terminal step in heme biosynthesis, the insertion of ferrous iron into protoporphyrin IX to form protoheme, is catalyzed by the enzyme ferrochelatase (EC 4.99.1.1). A number of highly conserved residues identified from the crystal structure of human ferrochelatase as being in the active site were examined by site-directed mutagenesis. The mutants Y123F, Y165F, Y191H, and R164L each had an increased K(m) for iron without an altered K(m) for porphyrin. The double mutant R164L/Y165F had a 6-fold increased K(m) for iron and a 10-fold decreased V(max). The double mutant Y123F/Y191F had low activity with an elevated K(m) for iron, and Y123F/Y165F had no measurable activity. The mutants H263A/C/N, D340N, E343Q, E343H, and E343K had no measurable enzyme activity, while E343D, E347Q, and H341C had decreased V(max)s without significant alteration of the K(m)s for either substrate. D340E had near-normal kinetic parameters, while D383A and H231A had increased K(m)s for iron. On the basis of these data and the crystal structure of human ferrochelatase, it is proposed that residues E343, H341, and D340 form a conduit from H263 in the active site to the protein exterior and function in proton extraction from the porphyrin macrocycle. The role of H263 as the porphyrin proton-accepting residue is central to catalysis since metalation only occurs in conjunction with proton abstraction. It is suggested that iron is transported from the exterior of the enzyme at D383/H231 via residues W227 and Y191 to the site of metalation at residues R164 and Y165 which are on the opposite side of the active site pocket from H263. This model should be general for mitochondrial membrane-associated eucaryotic ferrochelatases but may differ for bacterial ferrochelatases since the spatial orientation of the enzyme within prokaryotic cells may differ.

Clinical characteristics of outpatients at a psycho-oncology clinic in a radiation oncology department

BACKGROUND

Psychosocial care in cancer medicine has become increasingly important. The first psychiatric consultation-liaison (C-L) outpatient clinic in Taiwan was established in a department of radiation oncology in a medical center in Oct. 1998.

METHODS

From October 1998 through January 2000, 121 patients were referred for psychosocial evaluation. Six referred patients were excluded because of cerebral complications of malignant disease or coincidental psychiatric disorder. The remaining 115 patients were referred because of psychological problems related to their malignant disease. These patients were divided into 'depression related disorder' and 'anxiety related disorder' groups according to psychiatric standard diagnoses. The records of these referred patients were retrospectively analyzed based on the psychiatric diagnoses.

RESULTS

The outpatient utilization rate for psychiatric consultation escalated from 0% to 5.92% after the C-L clinic was established. Patients with nasopharynx, breast, and head and neck cancer had higher referral, rates (over 10%) than patients with other types of cancer. There were significant differences in major subjective psychiatric problems and psychological reactions between patients with psychiatric diagnosis and those without psychiatric diagnosis. Cancer patients who were diagnosed with 'depression related disorder' visited this clinic more times than those with 'anxiety related disorder'. The former received antidepressant drugs more frequently than the latter. There were also more multiple visits in the former group than the latter group.

CONCLUSION

Locating a C-L clinic in a radiation oncology department improves access to psychiatric evaluation, early detection and continuous intervention can then be offered to cancer patients with anxiety or depression, especially those with 'depression related disorder'.

The 2.0 A structure of human ferrochelatase, the terminal enzyme of heme biosynthesis

Human ferrochelatase (E.C. 4.99.1.1) is a homodimeric (86 kDa) mitochondrial membrane-associated enzyme that catalyzes the insertion of ferrous iron into protoporphyrin to form heme. We have determined the 2.0 A structure from the single wavelength iron anomalous scattering signal. The enzyme contains two NO-sensitive and uniquely coordinated [2Fe-2S] clusters. Its membrane association is mediated in part by a 12-residue hydrophobic lip that also forms the entrance to the active site pocket. The positioning of highly conserved residues in the active site in conjunction with previous biochemical studies support a catalytic model that may have significance in explaining the enzymatic defects that lead to the human inherited disease erythropoietic protoporphyria.

Ferrochelatase at the millennium: structures, mechanisms and [2Fe-2S] clusters

Ferrochelatase (E.C. 4.99.1.1, protoheme ferrolyase) catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme (heme). In the past 2 years, the crystal structures of ferrochelatases from the bacterium Bacillus subtilis and human have been determined. These structures along with years of biophysical and kinetic studies have led to a better understanding of the catalytic mechanism of ferrochelatase. At present, the complete DNA sequences of 45 ferrochelatases from procaryotes and eucaryotes are available. These sequences along with direct protein studies reveal that ferrochelatases, while related, vary significantly in amino acid sequence, molecular size, subunit composition, solubility, and the presence or absence of nitric-oxide-sensitive [2Fe-2S] cluster.

Cyto- and chemoarchitecture of basal forebrain cholinergic neurons in the common marmoset (Callithrix jacchus)

The cyto- and chemoarchitecture of basal forebrain cholinergic neurons (BFCN) was investigated in the lower primate, the common marmoset (Callithrix jacchus). A large population of magnocellular, hyperchromic, and choline acetyltransferase (ChAT)-positive neurons was detected in the marmoset basal forebrain. The distribution of these neurons was similar to those in higher primates. Thus, ChAT-positive neurons were observed in the medial septum (Ch2), the vertical (Ch2) and horizontal (Ch3) limbs of the diagonal band of Broca, and the nucleus basalis of Meynert (Ch4). The Ch4 complex was relatively well differentiated and displayed distinct sectors. We detected anterior (Ch4a, with a medial and a lateral subdivision), intermediate (Ch4i, with a dorsal and a ventral subdivision), and posterior (Ch4p) sectors in the marmoset Ch4. The Ch4i was relatively small while the Ch4p was large. Similar to the rodent, the marmoset Ch1 extended quite a distance posteriorly, and the Ch4p displayed a major interstitial component distributed within the globus pallidus, its medullary laminae, and the internal capsule. Virtually all of the marmoset BFCN displayed acetylcholinesterase activity, and low affinity (p75(NTR)) and high affinity (Trk) neurotrophin receptor immunoreactivity. A majority contained immunoreactivity for calbindin-D(28K) and calretinin. Many of the Ch4 neurons also displayed tyrosine hydroxylase immunoreactivity. The BFCN lacked galanin immunoreactivity, but were innervated by galanin-positive fibers. None of the marmoset BFCN were NADPH-d-positive. Thus, the BFCN display major anatomical and biochemical differences in the marmoset when compared with higher primates. The marmoset BFCN also display many characteristics common to other primates. This fact, combined with the relatively short life span of the marmoset, indicates that this species may be ideal for studies of age-related changes in the BFCN.

Concomitant neuroleptic malignant syndrome and lithium intoxication in a patient with bipolar I disorder: case report

The purpose of this report is to remind clinicians of the risk of the simultaneous occurrence of neuroleptic malignant syndrome (NMS) and lithium intoxication. A 39-year-old female with bipolar I disorder was admitted to our psychiatric ward due to relapse of a manic episode and a suicide attempt in which she had ingested 20 to 30 tablets of lithium (300 mg/tablet) 12 hours before admission. Except for intramuscular injection of 5 mg of haloperidol 30 minutes after admission, the patient received no antipsychotic drugs during her hospitalization. Six hours after admission, she began to show symptoms of NMS. Lithium intoxication was also found. Within a week, her condition had stabilized with no neurological complications or cognitive deficits noted during the following 4 months. Discussed in this case report are the risk factors of NMS found in this patient, drug interactions of lithium and antipsychotic agents as related to NMS, and problems in clinical management.

Focal pathology in the Edinger-Westphal nucleus explains pupillary hypersensitivity in Alzheimer's disease

Patients who suffer from Alzheimer's disease (AD) and a sub-population of community-dwelling elders show an exaggerated pupillary reaction to dilute tropicamide, a cholinergic antagonist. This finding may serve as an early diagnostic marker of AD. Here we report a likely pathological basis for this hypersensitive pupillary response. Our observations indicate that the Edinger-Westphal nucleus (EW), a known center for the control of pupillary function, is a selective target of Alzheimer pathology early in the course of the disease. In all AD cases examined, the EW contained plaques and tangles. In contrast, the adjacent somatic portion of the oculomotor complex was virtually spared of pathology. Early pathology in the EW is likely to initiate a cascade of events that may give rise to pupillary hypersensitivity.

Purification, crystallization and preliminary X-ray analysis of Drosophila melanogaster ferrochelatase

Ferrochelatase (protoheme ferrolyase, E.C. 4.99.1.1), the terminal enzyme in the heme biosynthetic pathway, catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme. In eukaryotes, the protein is associated with the inner surface of the inner mitochondrial membrane, and in higher animals the enzyme contains a [2Fe-2S] cluster. This cluster is highly sensitive to NO and is coordinated by four Cys residues whose spacing in the primary sequence is unique. Ferrochelatase from Drosophila melanogaster has been expressed in Escherichia coli with an amino-terminal six-histidine tag and purified to homogeneity. The protein has been crystallized with the [2Fe-2S] cluster intact. The crystals belong to space group I422, with unit-cell dimensions a = b = 158.1, c = 171.2 A and two molecules in the asymmetric unit, and diffract to 3. 0 A resolution.

Aging renders the brain vulnerable to amyloid beta-protein neurotoxicity

The formation of fibrillar deposits of amyloid beta protein (Abeta) in the brain is a pathological hallmark of Alzheimer's disease (AD). A central question is whether Abeta plays a direct role in the neurodegenerative process in AD. The involvement of Abeta in the neurodegenerative process is suggested by the neurotoxicity of the fibrillar form of Abeta in vitro. However, mice transgenic for the Abeta precursor protein that develop amyloid deposits in the brain do not show the degree of neuronal loss or tau phosphorylation found in AD. Here we show that microinjection of plaque-equivalent concentrations of fibrillar, but not soluble, Abeta in the aged rhesus monkey cerebral cortex results in profound neuronal loss, tau phosphorylation and microglial proliferation. Fibrillar Abeta at plaque-equivalent concentrations is not toxic in the young adult rhesus brain. Abeta toxicity in vivo is also highly species-specific; toxicity is greater in aged rhesus monkeys than in aged marmoset monkeys, and is not significant in aged rats. These results suggest that Abeta neurotoxicity in vivo is a pathological response of the aging brain, which is most pronounced in higher order primates. Thus, longevity may contribute to the unique susceptibility of humans to Alzheimer's disease by rendering the brain vulnerable to Abeta neurotoxicity.

Relationship between plaques, tangles, and loss of cortical cholinergic fibers in Alzheimer disease

Recent observations in our laboratory have indicated substantial and systematic regional variations in the loss of cortical cholinergic fibers in Alzheimer disease (AD). Previous attempts to study the relationship between cortical cholinergic loss and the density of cortical pathological lesions have resulted in conflicting findings. Furthermore, most reports have correlated density of plaques and tangles with the residual level of cholinergic innervation rather than its loss. The purpose of the present study was to determine the relationship between loss of cholinergic axons and density of tangles and beta-amyloid (Abeta) deposits in various cortical areas of AD brains. Abeta deposits and tangles were observed throughout the cerebral cortex. Quantitative analysis revealed almost no correlation between loss of cholinergic fibers and the density of Abeta deposits. Qualitative observations revealed similar results when cored and neuritic plaques were considered separately. By contrast, cholinergic fiber loss displayed a significant correlation with the density of tangles (r = 0.52-0.79). However, in a few areas, such as the cingulate cortex, tangle density appeared to be unrelated to the loss of cholinergic fibers. These results indicate that cortical cholinergic denervation in AD is related to cytoskeletal pathology. However, the lack of a perfect relationship with cytoskeletal pathology implicates additional factors in the cholinergic pathology of AD.

Age-related loss of calbindin from human basal forebrain cholinergic neurons

Loss of basal forebrain cholinergic neurons (BFCN) occurs in many age-related neurological diseases. Although age is the common risk factor in these disorders, no consistent age-related changes have been reported in the human BFCN. We investigated age-related alterations in choline acetyltransferase (ChAT), low-affinity nerve growth factor receptor (p75LNGFR) and calbindin-D28k (CalBP) immunoreactivity in the human BFCN. No significant age-related changes were observed in ChAT or p75LNGFR immunoreactivity. By contrast, normal aging was accompanied by a selective, substantial and significant loss of CalBP immunoreactivity from the BFCN. Other CalBP-positive neurons were unchanged. Loss of the calcium buffering capacity conferred by CalBP may leave the BFCN vulnerable to damage in neurodegenerative disorders.

Crystallization and preliminary crystallographic data for the augmenter of liver regeneration

A new cellular growth factor termed augmenter of liver regeneration (ALR) has been crystallized. ALR has been shown to have a proliferative effect on liver cells while at the same time producing an immunosuppressive effect on liver-resident natural killer cells and liver-resident mononuclear leukocytes. In addition, ALR appears to play an important role in the synthesis and stabilization of mitochondrial gene transcripts in actively regenerating cells. ALR crystals diffract to beyond 2 A resolution and belong to space group P2(1)2(1)2, with a = 125.1, b = 108.1 and c = 38.5 A. Based on four molecules per asymmetric unit, the Matthews coefficient is calculated to be 2.16 A(3) Da(-1) which corresponds to a solvent content of 43%.

Crystal structure of the neurophysin-oxytocin complex

The first crystal structure of the pituitary hormone oxytocin complexed with its carrier protein neurophysin has been determined and refined to 3.0 A resolution. The hormone-binding site is located at the end of a 3(10)-helix and involves residues from both domains of each monomer. Hormone residues Tyr 2, which is buried deep in the binding pocket, and Cys 1 have been confirmed as the key residues involved in neurophysin-hormone recognition. We have compared the bound oxytocin observed in the neurophysin-oxytocin complex, the X-ray structures of unbound oxytocin analogues and the NMR-derived structure for bound oxytocin. We find that while our structure is in agreement with the previous crystallographic findings, it differs from the NMR result with regard to how Tyr 2 of the hormone is recognized by neurophysin.

Effect of beef tenderness on consumer satisfaction with steaks consumed in the home and restaurant

Loin steaks were eaten by 67 consumers over a 15-wk period (n = 739 consumer observations) to determine the consumer acceptability of beef tenderness in the home and a "white table cloth" restaurant. Steaks were rated for tenderness, juiciness, flavor, and overall palatability on an 8-point scale. The acceptability levels for tenderness were established based on Warner-Bratzler shear (WBS) force values, tenderness ratings, and a chisquare analysis of the judgment of tenderness and overall acceptability by the same consumers in both the home and restaurant. Results based only on observations from consumers in Lubbock, TX indicated that the beef industry should target production of beef steaks that have a Warner-Bratzler shear force value of 4.1 kg or less to ensure high levels (98%) of consumer acceptability. Results suggest that an acceptable level of beef tenderness for consumers can be determined and WBS values can be used as criteria for determining which steaks will be considered acceptably tender to consumers before distribution to retail outlets. The beef industry needs to conduct a nationwide research study to determine whether the results from this study will apply to all U.S. beef consumers.

Restaurant consumer acceptance of beef loin strip steaks tenderized with calcium chloride

Beef strip loins from either the right or left side of 22 carcasses of Bos indicus-type steers were injected with 200 mM calcium chloride (CaCl2) solution at 5% (wt/wt) to determine its effect on tenderness and other selected quality traits of steaks. Loins from opposite sides of the carcasses were untreated and served as the control. The steaks were evaluated for tenderness, juiciness, flavor intensity, tenderness acceptability, and overall acceptability by 62 restaurant consumers over a 6-wk period. The CaCl2 injection improved (P < .05) tenderness and flavor intensity ratings by the restaurant consumers. Tenderness acceptability and overall acceptability were improved 23 and 17%, respectively, by the CaCl2 injection. Flavor was not compromised by the CaCl2 injection. The CaCl2-treated steaks were rated superior(P < .05) for flavor compared to the control steaks. Restaurant consumers preferred the beef loin strip steaks injected with 200 mM CaCl2 at 5% (wt/wt). The results of this study are interpreted to indicate that, from a restaurant consumer perspective, CaCl2 injection is an acceptable means of making beef a more consistently tender product.

Microbiology of hot-fat-trimmed beef

The effects of removal of fat from hot beef carcasses on the shelf life of beef involved measuring the incidence of aerobic (TPC), lactic (LAC), and coliform (TCC) bacteria and the pathogen Escherichia coli (EC) from alternate sides that were hot-fat trimmed (HFT) or not trimmed (NFT) then subjected to a conventional 24-h chill. The biceps femoris, psoas major, longissimus thoracis et lumborum, and supraspinatus muscles were assayed. Higher (P < .05) TPC and EC counts were found for all muscles at 0 d than at 7 and 14 d of storage. The LAC and TCC counts were higher (P < .05) on all muscles after the 14 d of storage than after 0 or 7 d of storage. The significant differences in microbial counts were less than one log 10/g of tissue and therefore are of questionable importance. The HFT did not increase carcass microbial load compared with NFT. This study showed that HFT and accelerated processing of beef for the production of lean retail cuts did not adversely affect the shelf-life of vacuum-packaged beef.

Effects of breed type and accelerated fat removal on subprimal yields and carcass values

Nine Brown Swiss and nine English crossbred steers representing the industry standard were slaughtered to determine the effects of cattle type and hot fat removal on subprimal yields and carcass value. After dressing, cod fat, kidney, pelvic, and heart fat (KPHF), and subcutaneous fat thicker than .6 cm was removed from the right side of each carcass (HFT). The left side was not hot-fat trimmed (NFT). Both sides were fabricated into subprimal cuts with no more than .6 cm of subcutaneous fat. Carcass side values were adjusted to a 300-kg chilled carcass weight basis. All comparisons were made for the carcasses using a USDA Select quality grade end point. English crossbred steer carcasses had more (P < .05) subcutaneous fat on the loin and chuck and more (P < .05) total hot fat trim, when KPHF was not included, than Brown Swiss steers (P < .05). Brown Swiss steers had more (P < .05) KPHF. Hot-fat trimmed sides had higher (P < .05) percentage yields from the chuck, brisket, foreshank, rib, plate, round primal cuts, and most of the subprimal cuts than NFT sides, but the primal loin percentage was higher (P < .05) in the NFT sides. The total subprimal cuts yield was approximately 5% higher for the HFT sides than for the NFT sides, and the total fat trim during fabrication was more than 6% less. When the value of the sides was calculated from unadjusted weights, the NFT sides were approximately $26.50 more valuable than the HFT sides.(ABSTRACT TRUNCATED AT 250 WORDS)

Oblique sliding metatarsal osteotomy for pressure metatarsalgia

The transverse arch of the foot is formed by metatarsals which heads lie in a straight line to endure most of the loading of the forefoot. Malalignment of one or more metatarsal heads will result in increased loading and produce local tender plantar callosity. The treatment of pressure metatarsalgia must aim for it's pathomechanic cause, that is, hyper-extension of metatarsophalangeal joint. We have modified the distal metatarsal osteotomy to treat 40 toes in 22 cases. Follow up for an average of 21.3 months (ranging from 18 months to 31 months) indicated 19 cases (86.4%) with satisfactory results. The 3 cases with unsatisfied results were all due to early removal of the pin. Maximum oblige sloping of the osteotomy makes the osteotomy slide more easily and ensures union. Intramedullary pinning and early weight bearing maintain the osteotomic alignment, prevent foot stiffness and allow the distal fragment telescopes to be adequately positioned to prevent over correction which leads to transfer lesion. Compared to other methods, modified metatarsal osteotomy is less invasive, preserves natural structure, is easily performed and easy cared for which leads to effective and stable results.

Positive inotropic and toxic action of direct lytic factor on isolated working guinea pig hearts

The positive inotropic and the toxic effects of direct lytic factor (DLF) on the isolated working guinea pig hearts were studied. As compared with baseline values, DLF 1-10 micrograms.ml-1 increased aortic flow up to 138% cardiac output 116%, left ventricular pressure volume work 136%, left ventricular pressure 114%, dP/dtmax 130%, Vmax 128%, and mean aortic systolic pressure 114%, but coronary flow was decreased by 16% on an average (n = 6). However, heart rate remained constant, myocardial oxygen consumption and efficiency were changed little. The cardiotonic effect of DLF was also observed by recording the isometric contractions of the isolated guinea pig papillary muscles and by determining the left ventricular pressure and dP/dtmax in anesthetized dogs. Neither spontaneously beating rate of right atrium nor the excitability of left atrium in vitro was affected by DLF. The results show that DLF is one of the cardiotonic agents without chronotropic effect and its coronary vasoconstriction effect plays an important part in heart failure.

Effects of infused glucose, sodium and potassium chlorides and polyphosphates on palatability of hot-boned pork

Longissimus muscle sections were excised from eight pork carcasses 1 h postmortem and sectioned into six .5-kg roasts to determine the effects of glucose, salt and polyphosphates (aqueous solution to 110% of fresh weight) on palatability of hot-boned pork. Treatments were hot-boned control (HB) with no infusion or infusions of 2% KCl and 3% of a 1:1 mixture of sodium hexametaphosphate and sodium pyrophosphate (PP) plus either 8% NaCl; 2% glucose (G) plus 6% NaCl; 6% G plus 2% NaCl; or 8% G. Another muscle section was chilled at 0 degrees C for 24 h on each carcass as a cold-processed control (CP). The roasts were frozen until cooked and evaluated by a sensory panel. The infused groups were more tender, juicy and salty and higher in moisture and ash but lower in protein content than either the CP or HB controls (P less than .05). The fat content of the infused groups was lower than of the HB control but was not different from that of the CP control. Either 2% NaCl plus 6% G or equal amounts (4%) of NaCl and G produced the most tender and juicy product. The substitution of 4% glucose for NaCl not only reduced the NaCl content of the infusion solution, but also improved the palatability of the meat. This substitution allows production of a hot-boned, lower-sodium precooked pork that is tender and juicy.

Laser-induced multiphoton fluorescence of hemoglobin

Hemoglobin (Hb) and other samples were irradiated by the 1064 nm nanosecond pulses of an Nd:YAG laser. At room temperature, we observed two red fluorescence bands, which resulted from the absorption of two 1064 nm photons in Hb, and measured the fluorescence emission spectra in the red spectral region for Hb and hematoporphyrin derivative. A red shift of the wavelength and a mirror image in the intensity of fluorescence emissions by two-photon excitation were observed. It is shown that the fluorescence of Hb originates from the heme group. In addition, we also observed fluorescence emission at 392 nm for Hb, which may be from its tryptophan groups.

Time character of phase-conjugate reconstructed waves

The time dependence of phase-conjugate wave generation in liquids has been studied using four-wave mixing of picosecond laser pulses and different polarization configurations. Response and decay times of some possible physical processes contributing to the phase-conjugate wave generation have been measured.

Physical factors influencing fluid reabsorption from Henle's loop

Our objective was to produce reductions in the luminal volume of Henle's loop and increases in linear flow velocity through the loop. We did this in a recollection micropuncture study by collecting fluid with and without suction from early distal tubules. With suction, transit time of fast green dye through the loop decreased by 34%, calculated loop volume decreased by 28%, and fractional water reabsorption fell from 73.6 to 70.3% (p smaller than 0.025) in water diuretic rats. Absolute water reabsorption did not decrease significantly. In urea-saline dieuretic rats transit time decreased 25%, calculated loop volume decreased 22%, fractional reabsorption fell from 59.0 to 51.7% (smaller than 0.001), and absolute reabsorption decreased by 2.3 nl/min (p smaller than 0.025). Single nephron glomerular filtration rate, distal tubular sodium concentration, and osmolality were unaffected. The less pronounced effect of collection with suction in water diuretic rats may be related to the lower medullary fluid osmolality, which was 338 plus or minus 9 (S.E.) mOsmol/kg as compared to 497 plus or minus 35 in urea saline diuretic rats. Collecting fluid with suction from late proximal tubules did not alter glomerular filtration rate or fractional water reabsorption. Stumpe et al. ((1970) J. Clin. Invest. 49, 1200-1212) noted an inverse correlation between fluid reabsorption from Henle's loop and flow velocity in rats with hypertension or congestive heart failure. One can reproduce this correlation by artificially altering the transmural pressure gradient in the loop.