Overview of the chemistry and biological activities of natural atisine-type diterpenoid alkaloids.

Atisine-type C20-diterpenoid alkaloids (DAs) are a very important class of diterpenoid alkaloids, which play an important role in the biosynthesis of DAs. To date, 87 atisine-type DAs and 11 bis-DAs containing an atisine unit have been reported from five genera in two families. The genus Spiraea in Rosaceae family could be regarded as the richest resource for atisine-type DAs, followed by the genera Delphinium and Aconitum in the Ranunculaceae family. Among the reported atisine-type DAs, several possess unprecedented skeletons. Natural atisine-type DAs have a wide range of biological activities, including antitumor, antiplatelet aggregation, biological control, and anti-inflammatory, analgesic, antiarrhythmic, and cholinesterase inhibitory effects, which are closely related to their structures. In particular, the antiparasitic effect of atisine-type DAs is more prominent than that of other types of DAs, which highlights their potential in antiparasite drug discovery. In summary, the high chemical and biological diversity of atisine-type DAs indicates their great potential as a vast resource for drug discovery.

DTI-ALPS index decreased in patients with Type 2 Diabetes Mellitus.

Backgrounds: Type 2 Diabetes Mellitus (T2DM) has become a significant global public health issue, characterized by a rising prevalence and associated deficits across multiple organ systems. Our study aims to utilize the DTI-ALPS technique to assess the change of ALPS index in T2DM patients, and to explore whether such changes are correlated with cognition level and diffusion parameters. Methods: The study involved 41 patients with T2DM (mean age, 60.49 ± 8.88 years) and 27 healthy controls (mean age, 58.00 ± 7.63 years). All subjects underwent MRI examination, cognitive assessment, and laboratory tests. Tract-based spatial statistics (TBSS) was used to evaluate white matter changes. GLM was performed to check the DTI-ALPS index difference between T2DM and HC groups. Spearman correlation analysis and partial correlation analysis were used to analyze the correlation between the DTI-ALPS index and diffusion properties & cognitive scores. Results: The results show that the ALPS index was lower in T2DM patients. MoCA score was significantly correlated with the ALPS index. Patients with T2DM had a significant increase in both mean diffusivity (MD) and radial diffusivity (RD) and decrease in fractional anisotropy (FA) compared to the HC group. Conclusion: The results suggest that the ALPS index is decreased in T2DM patients and associates with cognitive level.

Exploring the Role of Quantitative CT in Diagnosing Pancreatic Fat Deposition in Type 2 Diabetes Mellitus.

Objective: This study aimed to assess the correlation and consistency between quantitative CT (QCT) and MRI asymmetric echo least squares estimation iterative water-lipid separation sequence (IDEAL-IQ) in determining pancreatic fat content in patients with type 2 diabetes. Methods: A total of 67 patients with type 2 diabetes mellitus who met the inclusion criteria were included in the study. QCT and MRIIDEAL-IQ technologies were utilized to evaluate the patients quantitatively. The pancreatic head, body, and tail regions were examined to measure the fat content and obtain the CT pancreatic fat fraction (CT-PFF) and MRI pancreatic fat fraction (MR-PFF). Pearson correlation analysis examined the relationship between diabetes-related factors and CT-PFF/MR-PFF. Additionally, Bland-Altman analysis assessed the consistency between CT-PFF and MR-PFF. Results: Among the 67 patients, 33 were males and 34 were females. The average age was (66.55±6.23) years, with an average abdominal circumference of (83.34 ± 10.10) cm. The mean values for glycated hemoglobin, fasting blood glucose, BMI, and liver fat content were (6.97±1.07) mmol • L-1, (6.83±1.82) mmol • L-1, (24.02 ± 2.96) kg/m², and (5.28±2.76)%, respectively. Pearson correlation analysis indicated a significant correlation between abdominal circumference, liver fat content, and MR-PFF (r=0.261, 0.267, P < .05). However, no significant correlation was observed between age, glycated hemoglobin, fasting blood glucose, BMI, and MR-PFF (all, P > .05). The minimum and maximum values for CT-PFF among the 67 patients were 7.3% and 60.3%, respectively, with an average value of (19.90±10.61)%. For MR-PFF, the minimum and maximum values were 2% and 48%, respectively, with an average value of (12.21±10.71)%. Pearson correlation analysis demonstrated a significant correlation between CT-PFF and MR-PFF (r = .842, P < .05). Bland-Altman analysis revealed an average bias value of 7.7% and a standard deviation of 5.6% for CT-PFF and MR-PFF. The mean 95% confidence interval ranged from 4.15% to 19.75% (P < .05), with 64 cases falling within this interval and 3 cases falling outside. Conclusion: A correlation exists between pancreatic fat content, abdominal circumference, and liver fat content. Both QCT and MRI can accurately quantify pancreatic fat content, and their correlation and consistency are relatively ideal. QCT technology is particularly suitable for patients with contraindications for magnetic resonance examination.

Clinical, epidemiological, and genotypic characteristics of rotavirus infection in hospitalized infants and young children in Yunnan Province.

Rotaviruses are the most important pathogenic cause of non-bacterial diarrhea in infants and children. Approximately 60% of hospital admissions for acute diarrhea worldwide are caused by rotavirus infection. Rotavirus infection and hospitalization among children in China are a social burden, resulting in economic loss. The prevalence and geographical distribution of rotavirus genotypes is variable, partially due to population migration. Due to the unique geographical conditions and climate in Yunnan Province, several viruses with new genotypes have emerged, and multiple genotypes have become co-epidemic. In this study, rotavirus infection screening and genetic characterization of epidemic strains were performed in 149,492 infants and children admitted to hospitals in six representative prefectures in Yunnan Province between 2019 and 2021. The prevalence of rotavirus infection was 13.39% and was highest in January and lowest in September. G9P[8] was the main epidemic rotavirus genotype. Other epidemic genotypes included G2P[4], G8P[8], G9P[4], G2P[8], G3P[8], G4P[8], G3P[4], and G4P[6]. Phylogenetic analysis revealed that locally epidemic strains were influenced by importation of strains from neighboring provinces and other Asian countries. These findings provide a scientific basis for rotavirus prevention and control and lay a foundation for preliminary studies to establish a rotavirus surveillance network in Yunnan Province.

[Quality of Life and Its Influencing Factors Among Schizophrenia Patients Living in Urban and Rural Areas].

Objective: To investigate the status quo of the quality of life of schizophrenia patients in a city in Sichuan Province and to explore, thereof, the urban-rural differences in the factors influencing their quality of life. Methods: A total of 824 schizophrenia patients were selected for the study through multistage stratified cluster random sampling method. All the subjects were selected from a pool of patients covered by the Sichuan Provincial Information System for the Comprehensive Management of Severe Mental Disorders. Questionnaire surveys were conducted with the Schizophrenia Quality of Life Scale (SQLS), the Social Support Rating Scale (SSRS), the general circumstance questionnaire, and the lifestyle questionnaire. In addition, univariate and multiple linear regression models were used to analyze the influencing factors of quality of life among schizophrenia patients living in urban areas and those in rural areas. Results: Rural patients had poorer quality of life than urban patients did in all measurement domains ( P<0.05). Marital status, vocational skills, physical exercise, and social support were influencing factors of the quality of life among urban patients ( P<0.05). Age, marital status, annual household income, vocational skills, participation in community rehabilitation activities, and the time required to walk to the nearest medical institution were influencing factors of the quality of life among rural patients ( P<0.05). Conclusion: Targeted measures for the enhancement of the quality of life of schizophrenia patients should be formulated on the basis of urban and rural characteristics in terms of economic support, vocational skills training, input in mental health services, community rehabilitation services, and social support.

New diterpenoid alkaloids from Delphinium pachycentrum Hemsl.

Six diterpenoid alkaloids, namely, pachycentine (1), deacetylswinanine A (2), siwanine A (3), tatsiensine (4), deacetyltatsiensine (5), and 6-deoxydeltamine (6), were isolated from a China-specific Delphinium plant (family Ranunculaceae), Delphinium pachycentrum Hemsl. Their structures were established via detailed spectroscopic analyses, including IR, HR-ESI-MS, 1D and 2D NMR techniques. Pachycentine (1) is a previously undescribed hetisine-type C20-diterpenoid alkaloid, and compounds 5 and 6 were synthetic intermediates newly identified as natural products. In addition, compounds 2-4 were isolated from this species for the first time. The chemotaxonomic significance of all the isolates was summarized. Moreover, the new compound was evaluated for its potential anti-inflammatory effect using LPS-stimulated RAW 264.7 macrophages.

Grandiflolines A-F, new anti-inflammatory diterpenoid alkaloids isolated from Delphinium grandiflorum.

Delphinium grandiflorum L. (family Ranunculaceae), one of the most important and widely distributed Delphinium species, has received considerable interest due to its extremely high medicinal value. The discovery of novel metabolites from D. grandiflorum supported and broadened its application as an herbal medicine. In this study, the whole herb of D. grandiflorum was phytochemically investigated to obtain fourteen C19-lycaconitine-type diterpenoid alkaloids (1-14), including six undescribed alkaloids, grandiflolines A-F (1-6). The structural elucidation of them was accomplished by detailed spectroscopic analyses, mainly including HR-MS, 1D and 2D NMR (1H-1H COSY, NOESY, HMBC and HSQC), and IR spectra. New alkaloids 1-3 and 5 possess a characteristic △2,3 functional group in the A ring, while compounds 5 and 6 feature a rare OH-16 substituent. In addition, known compounds 7-12 were isolated from D. grandiflorum for the first time. Moreover, according to its medicinal use, new alkaloids 1-6 were estimated for their potential in vitro anti-inflammatory effects, and some of them exhibited inhibitory effects on NO production in LPS-activated RAW 264.7 macrophages. Our work enriched the chemical diversity of D. grandiflorum and the genus Delphinium and presented beneficial information for further investigations.

GR silencing impedes the progression of castration-resistant prostate cancer through the JAG1/NOTCH2 pathway via up-regulation of microRNA-143-3p.

BACKGROUND: Despite notable progression from a therapeutic point of view, castration resistant prostate cancer (CRPC) remains a clinical significant stumbling block. The current study aimed to elucidate the functional role of the gene glucocorticoid receptor (GR) in CRPC, and identify the contributions of the GR gene in CRPC in connection with microRNA-143-3p (miR-143-3p)/Jagged1 (JAG1)/NOTCH2. METHODS: The expression of GR and miR-143-3p in CRPC tissues and cells as well as JAG1/NOTCH2 expression in CRPC tissues was initially determined by quantitative polymerase chain reaction and Western blot analyses. The relationship among GR, JAG1, NOTCH2 and miR-143-3p was subsequently verified using the dual-luciferase reporter gene assay. ChIP assay confirmed the binding of GR to miR-143-3p promoter. Gain- and loss-function approaches were applied to ascertain the role of GR and miR-143-3p in progression of CRPC. Additionally, xenograft tumor models in nude mice were established to further confirm our results. RESULTS: GR was found to be highly expressed while miR-143-3p was lowly expressed in the CRPC tissues and cells. Silencing GR reduced migration, invasion, proliferation and increased apoptosis of CRPC cells. GR was enriched in the miR-143-3p promoter region and could down-regulate miR-143-3p expression. The overexpression of miR-143-3p led to a reduction in the migration, invasion, proliferation and increased apoptosis of CRPC cells. JAG1 and NOTCH2 were the target genes of miR-143-3p, and GR up-regulated the JAG1/NOTCH2 expression by down-regulating miR-143-3p. Silencing JAG1/NOTCH2 inhibited epithelial-mesenchymal transition and CRPC progression in vitro. Furthermore, the in vitro findings were reproduced in the in vivo experiments. CONCLUSION: The key findings of the current study demonstrated that silencing GR suppressed the progression of CRPC through the JAG1/NOTCH2 pathway via up-regulation of miR-143-3p.

FgIlv3a is crucial in branched-chain amino acid biosynthesis, vegetative differentiation, and virulence in Fusarium graminearum.

Dihydroxyacid dehydratase (DHAD), encoded by ILV3, catalyses the third step in the biosynthetic pathway of branched-chain amino acids (BCAAs), which include isoleucine (Ile), leucine (Leu), and valine (Val). Enzymes involved in BCAA biosynthesis exist in bacteria, plants, and fungi but not in mammals and are therefore attractive targets for antimicrobial or herbicide development. In this study, three paralogous ILV3 genes (FgILV3A, FgILV3B, and FgILV3C) were identified in the genome of Fusarium graminearum, the causal agent of Fusarium head blight (FHB). Deletion of FgILV3A alone or combined with FgILV3B or FgILV3C indicated an important role for FgILV3A in BCAA biosynthesis. FgILV3A deletion mutants lost the ability to grow on medium lacking amino acids. Exogenous supplementation of 1 mM Ile and Val rescued the auxotrophy of ΔFgIlv3A, though 5 mM was required to recover the growth defects in ΔFgIlv3AB and ΔFgIlv3AC strains, indicating that FgIlv3b and FgIlv3c exhibit redundant but accessory roles with FgIlv3a in BCAA biosynthesis. The auxotrophy of ΔFgIlv3A resulted in pleiotropic defects in aerial hyphal growth, in conidial formation and germination, and in aurofusarin accumulation. In addition, the mutants showed reduced virulence and deoxynivalenol production. Overall, our study demonstrates that FgIlv3a is crucial for BCAA biosynthesis in F. graminearum and a candidate fungicide target for FHB management.

Bio-Derived Hierarchical Multicore-Shell Fe2N-Nanoparticle-Impregnated N-Doped Carbon Nanofiber Bundles: A Host Material for Lithium-/Potassium-Ion Storage.

Despite the significant progress in the fabrication of advanced electrode materials, complex control strategies and tedious processing are often involved for most targeted materials to tailor their compositions, morphologies, and chemistries. Inspired by the unique geometric structures of natural biomacromolecules together with their high affinities for metal species, we propose the use of skin collagen fibers for the template crafting of a novel multicore-shell Fe2N-carbon framework anode configuration, composed of hierarchical N-doped carbon nanofiber bundles firmly embedded with Fe2N nanoparticles (Fe2N@N-CFBs). In the resultant heterostructure, the Fe2N nanoparticles firmly confined inside the carbon shells are spatially isolated but electronically well connected by the long-range carbon nanofiber framework. This not only provides direct and continuous conductive pathways to facilitate electron/ion transport, but also helps cushion the volume expansion of the encapsulated Fe2N to preserve the electrode microstructure. Considering its unique structural characteristics, Fe2N@N-CFBs as an advanced anode material exhibits remarkable electrochemical performances for lithium- and potassium-ion batteries. Moreover, this bio-derived structural strategy can pave the way for novel low-cost and high-efficiency syntheses of metal-nitride/carbon nanofiber heterostructures for potential applications in energy-related fields and beyond.

A cross-circulated bicephalic model of head transplantation.

AIMS: A successful cephalosomatic anastomosis ("head transplant") requires, among others, the ability to control long-term immune rejection and avoidance of ischemic events during the head transference phase. We developed a bicephalic model of head transplantation to study these aspects. METHODS AND RESULTS: The thoracic aorta and superior vena cava of a donor rat were anastomosed with the carotid artery and extracorporeal veins of a recipient rat by vascular grafts. Before thoracotomy in the donor rat, the axillary artery and vein of the donor were connected to the carotid and the extracranial vein of the third rat through a silicone tube. The silicone tube was passed through a peristaltic pump to ensure donor brain tissue blood supply. There is no ischemia reperfusion injury in donor brain tissue analyzed by electroencephalogram. Postoperative donor has pain reflex and corneal reflex. CONCLUSIONS: Peristaltic pump application can guarantee the blood supply of donor brain tissue per unit time, while the application of temperature change device to the silicone tube can protect the brain tissue hypothermia, postoperative experimental data show that there is no brain tissue ischemia during the whole operation. The application of vascular grafting can also provide the possibility of long-term survival of the model.

Predicting the Potential Distribution of Polygala tenuifolia Willd. under Climate Change in China.

Global warming has created opportunities and challenges for the survival and development of species. Determining how climate change may impact multiple ecosystem levels and lead to various species adaptations is necessary for both biodiversity conservation and sustainable biological resource utilization. In this study, we employed Maxent to predict changes in the habitat range and altitude of Polygala tenuifolia Willd. under current and future climate scenarios in China. Four representative concentration pathways (RCP2.6, RCP4.5, RCP6.0, and RCP8.5) were modeled for two time periods (2050 and 2070). The model inputs included 732 presence points and nine sets of environmental variables under the current conditions and the four RCPs in 2050 and 2070. The area under the receiver-operating characteristic (ROC) curve (AUC) was used to evaluate model performance. All of the AUCs were greater than 0.80, thereby placing these models in the "very good" category. Using a jackknife analysis, the precipitation in the warmest quarter, annual mean temperature, and altitude were found to be the top three variables that affect the range of P. tenuifolia. Additionally, we found that the predicted highly suitable habitat was in reasonable agreement with its actual distribution. Furthermore, the highly suitable habitat area was slowly reduced over time.

Distribution of HLA-A, -B, and -C alleles and HLA/KIR combinations in Han population in China.

We investigated polymorphisms of the human leukocyte antigen (HLA) class I (A, B, and C) loci of a Han population (n, 239) from the Yunnan province, Southwest China, using high-resolution polymerase chain reaction-Luminex (PCR-Luminex) typing. We combined the HLA data from this study with the KIR genotypes from a previous study of this Han population to analyze the combination of KIR/HLA ligands. A total of 27 HLA-A, 54 HLA-B, and 31 HLA-C alleles were found in this population. The frequencies of A*11:01, A*24:02, B*40:01, B*46:01, C*01:02, C*03:04, and C*07:02 were all > 10%. The following haplotypes were common, with frequencies > 5%: 1 A-B (A*02:07-B*46:01), 2 A-C (A*02:07-C*01:02, and A*11:01-C*07:02), 4 C-B (B*13:01-C*03:04, B*40:01-C*07:02, B*46:01-C*01:02 and B*58:01-C*03:02), and 1 A-C-B (A*02:07-C*01:02-B*46:01). Analysis of KIR3D and their ligands HLA-A3/A11 and HLA-Bw4 showed that the frequencies of 3DL2(+)-A3/A11(+) and 3DL2(+)-A3/A11(-) were 0.527 and 0.473, and the frequencies of 3DL1(+)-Bw4(+), 3DL1(+)-Bw4(-), 3DL1(-)-Bw4(+), and 3DL1(-)-Bw4(-) were 0.552, 0.397, 0.038, and 0.013, respectively. The results of KIR/HLA-C combination analysis showed that all individuals had at least one inhibitory or activating KIR/HLA-C pair, and one KIR/HLA-C pair was the most frequent (157/239), followed by two pairs (46/239), three pairs (33/239), and no pairs (3/239). Comparison of KIR gene and HLA gene and their pair frequency between Yunnan Han and the isolated Han (FYDH) who also lived in Yunnan province showed no significant difference (P > 0.05) in KIR frequencies, but significant differences (P < 0.05) for some HLA allele frequencies. In addition, there was no significant difference (P > 0.05) between the two populations for KIR/HLA pairs.

[Detection and comparison of physiological indexes in the wild and laboratory tree shrew].

To provide fundamental basis for the tree shrew models of human diseases, we examined and compared the physiological and biochemical indexes between wild and laboratory tree shrews. Blood samples were taken from 54 wild tree shrews that were housed in laboratory for 1-2 months, and from 54 first-generation of the laboratory tree shrews; each group had nearly equal male and female composition. Some of the first reported physiological and biochemical indexes were showed no significant differences between genders, and these indexes in laboratory tree shrews were as follows [medium (inter-quartile range) ]: CK 1449 (956) U/L, CTNI 5.94 (7.23) ug/L, TBA15.6 (19.7) µmol/L, FRUC 393.5 (80.8) µmol/L and LDL-C0.36 (0.32); and in the wild tree shrews, 986 (564) U/L, 4.01 (4.10) µg/L, 20.0 (20.6) µmol/L, 379.0 (104.0) µmol/L and 0.46 (0.23) mmol/L, respectively. In the laboratory tree shrews, the variations of physiological and biochemical indexes were smaller, but the mean values of some indicators related to liver and heart functions became higher. These data would be valuable for the development of tree shrew models of human diseases.

[Comparison of arbutin contents from Bergenia purpurascens in Yunnan].

OBJECTIVE: To determine arbutin contents in different populations of Bergenia purpurascens in Yunnan province, for screening out the best resource and best part of B. purpurascens. METHOD: The SB-C18 column was used with methanol-water (15: 85) as the mobile phase, at the flow rate of 1 mL x min(-1) and column temperature of 30 degrees C, and 282 nm was selected as the detected wavelength. RESULT: There were much significant differences in arbutin contents among various parts of the same B. population. The sequence of parts from high to low was lamina > petiole > root > rhizome. Arbutin contents in laminae of different B. populations were different at the most significant level and varied between 6.36% and 1.51%. Arbutin contents in rhizomes of different B. populations were also dignificantly different at varied between 1.72% and 0.40%. CONCLUSION: Lamina is the best part for extracting arbutin. B. population distributed in Laojunshan mountain in Lanping county is the best resource for arbutin exploitation in B. purpurascens.

A comparison of wavefront aberrations in eyes wearing different types of soft contact lenses.

PURPOSE: The purpose of this study is to investigate the optical quality of eyes wearing different types of soft contact lenses (sCLs) using wavefront aberrometry. METHOD: A psychophysical aberrometer (WFA1000B; BriteEye, SuZhou, China) was used to measure wavefront aberrations for 56 eyes of 28 subjects under four conditions: 1) without contact lenses (non-CL), 2) with lathe-cut contact lenses (lathe-cut CL; Shuliang, Weicon Optics, Shanghai, China), 3) with cast-molded contact lenses (cast-molded CL; Vistavue, J&J Vision Care, U.S.), and 4) with spun-cast contact lenses (spun-cast CL; Lanfenzhiji, Justcome Optics, Beijing, China). The three types of sCLs were made from different materials and lens design. The root mean square (RMS) values of the wavefront aberrations and individual Zernike aberrations were calculated and compared among the CL-wearing conditions. RESULTS: Astigmatism was not significantly changed by any of the three soft contact lenses when compared with the non-CL condition. However, a significant difference in the RMS values of higher-order aberrations was observed between the lens types (F=8.29, p<0.0001). Induced higher-order aberrations were found for both the cast-molded CL and the spun-cast CL conditions. There were significant differences in the aberrations in each of the higher orders between the CL conditions (F=3.77, p=0.011 for third order; F=5.31, p=0.002 for fourth order; F=13.86, p<0.0001 for fifth and higher orders). More higher-order Zernike aberrations such as coma and spherical aberration were induced by cast-molded CLs and/or the spun-cast CLs. CONCLUSION: Wavefront aberrations in the eyes with soft contact lenses vary from one individual lens type to another. Although the variation in wavefront aberrations could be attributed to the differences in the methods of manufacture, influences from other factors such as the lens material and lens design could not be excluded and deserve further investigation.

[Clinical effect of off-pump epicardial microwave ablation of atrial fibrillation].

OBJECTIVE: To apply the off-pump epicardial microwave ablation (MW) to treat the permanent atrial fibrillation (PAF) and evaluate the clinical effect. METHODS: From April 2003 to April 2005, a total of 46 patients with PAF underwent off-pump epicardial MW, including the patients with mitral valve disease (28 cases), mitral and aortic valve disease (5 cases), coronary artery disease (8 cases) and lone PAF (5 cases). FLEX 10 probe was placed around four pulmonary orifices and the access orifice of the inferior vena cava to tricuspid annulus. The microwave application was set 65 W, 90 s and a continuous ablation line was finished encircling the pulmonary veins. Subsequently, patients underwent either off-pump coronary artery bypass graft or valve surgery on-pump. Mean left atrial diameter was (52.5 +/- 15.3) mm, LVEF 42% - 70% before operation. All patients were followed up in the discharge, 3, 6, 12 months after surgery by standard 12-lead ECG, 24 h Holter, UCG and clinical examination. RESULTS: All procedures were completed successful on the off-pump cardiac surgery and 46 patients were converted sinus rhythm when the operations were performed. Mean ablation time was (37.7 +/- 7.8) min, without any related complications. At discharge, 3, 6 and 12 months follow-up, 63.0%, 66.7%, 72.7% and 80.6% of the patients kept sinus rhythm and left atrial diameter of < 50 mm. CONCLUSIONS: Using MW, electrical isolation of the pulmonary veins can be achieved epicardially without cardiopulmonary bypass support. Off-pump epicardial microwave ablation is an efficient option with an excellent benefit/risk ratio for the treatment of PAF with or without other cardio-surgical disease.

[The analysis of corneal topography for keratoconus].

OBJECTIVE: To investigate the refraction and videokeratographic characteristics of keratoconus. METHODS: 262 eyes of 147 patients with keratoconus were examined using autorefractor and computerized corneal topography, which generated the quantitative descriptors including refraction, keratometry, corneal astigmatism, the surface regularity index (SRI), the surface asymmetry index (SAI), and morphologic description. RESULTS: All patients were classified into four groups: suspect, mild, moderate and advanced group. The topographical configurations of the lesions were divided into bow-tie pattern subdivided into symmetric and asymmetric pattern, and non-bow-tie pattern including nipple, oval, global and anomalistic pattern. The bow-tie pattern mostly appeared symmetrical and occurred in suspect and mild cases. The nipple and oval pattern mostly occurred in mild and moderate ones located in the central or inferior paracentral cornea. The global pattern mostly occurred in moderate and advanced ones located in the central cornea. The anomalistic pattern occurred in advanced ones. Bilateral topography showed symmetrical in majority of patients with bilateral keratoconus. There was no correlation between the diameter of lesion and the refraction power of corneal apex (r = 0.208, P = 0.092). There was negative correlation between the distance from corneal center to the apex of lesion and the refraction power of corneal apex (r = -0.400, P = 0.001). CONCLUSIONS: Corneal topography is a sensitive method to detect the keratoconus earlier, which helps eye doctors to take appropriate measures to improve patients vision and avoid patients from undergoing excimer laser keratorefractive surgery. In addition, it can show the configuration of the lesion, which guide the fitting of hard contact lens.

Leaflet geometry extraction and parametric representation of a pericardial artificial heart valve.

Reverse engineering technology was used to reconstruct the complex leaflet geometry of a commercial pericardial valve in our study. Results show that the three-dimensional computer-aided design model of the leaflet surface can be rendered by fitting the surface either to cloud points or by a group of B-splines fitted to a set of cloud points that had been obtained by the process of laser-scanning digitizing. However, an acceptable smooth surface is usually not guaranteed and additional manipulation is required. An alternative method is introduced in this paper, which involves the fitting of an equation to the leaflet geometry to create a smooth surface. The geometrical profile of a pericardial artificial heart valve was scanned using a laser digitizing system. The leaflet profile is represented as a set of cloud points. A quadric surface is fitted to a set of unique points, which were located on the set of cloud points. A mathematical equation is obtained by solving a least-squares fit. The geometry of the fitted leaflet surface has been proven to be closely represented by an elliptical hyperboloid. The quadratic equations of the leaflet curvatures, calculated along both the circumferential and the radial directions, resulted in simple hyperbolic curvatures. The advantages of using elliptical hyperboloid geometry for the leaflet surface are discussed and compared with other types of conicoid geometries. The concepts of parametric representation of the leaflet geometry and parametric design for leaflets are discussed. A smooth surface without inflection points and with an adjustable surface area suitable for a series of stent sizes with incremented diameters is created by this method of a single parametric design. Finally, a generic method to apply the geometry extraction and parametric representation to most pericardial heart valve prostheses was discussed. The application to valves with natural shape was introduced, challenges were identified, and a technical solution was proposed.

Measurement and reconstruction of the leaflet geometry for a pericardial artificial heart valve.

This paper describes the measurement and reconstruction of the leaflet geometry for a pericardial heart valve. Tasks involved include mapping the leaflet geometries by laser digitizing and reconstructing the 3D freeform leaflet surface based on a laser scanned profile. The challenge is to design a prosthetic valve that maximizes the benefits offered to the recipient as compared to the normally operating naturally-occurring valve. This research was prompted by the fact that artificial heart valve bioprostheses do not provide long life durability comparable to the natural heart valve, together with the anticipated benefits associated with defining the valve geometries, especially the leaflet geometries for the bioprosthetic and human valves, in order to create a replicate valve fabricated from synthetic materials. Our method applies the concept of reverse engineering in order to reconstruct the freeform surface geometry. A Brown & Shape coordinate measuring machine (CMM) equipped with a HyMARC laser-digitizing system was used to measure the leaflet profiles of a Baxter Carpentier-Edwards pericardial heart valve. The computer software, Polyworks was used to pre-process the raw data obtained from the scanning, which included merging images, eliminating duplicate points, and adding interpolated points. Three methods, creating a mesh model from cloud points, creating a freeform surface from cloud points, and generating a freeform surface by B-splines are presented in this paper to reconstruct the freeform leaflet surface. The mesh model created using Polyworks can be used for rapid prototyping and visualization. To fit a freeform surface to cloud points is straightforward but the rendering of a smooth surface is usually unpredictable. A surface fitted by a group of B-splines fitted to cloud points was found to be much smoother. This method offers the possibility of manually adjusting the surface curvature, locally. However, the process is complex and requires additional manipulation. Finally, this paper presents a reverse engineered design for the pericardial heart valve which contains three identical leaflets with reconstructed geometry.