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1.
Clin Transl Oncol ; 26(10): 2395-2417, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38602644

ABSTRACT

The journey of cancer development is a multifaceted and staged process. The array of treatments available for cancer varies significantly, dictated by the disease's type and stage. Cancer-associated fibroblasts (CAFs), prevalent across various cancer types and stages, play a pivotal role in tumor genesis, progression, metastasis, and drug resistance. The strategy of concurrently targeting cancer cells and CAFs holds great promise in cancer therapy. In this review, we focus intently on CAFs, delving into their critical role in cancer's progression. We begin by exploring the origins, classification, and surface markers of CAFs. Following this, we emphasize the key cytokines and signaling pathways involved in the interplay between cancer cells and CAFs and their influence on the tumor immune microenvironment. Additionally, we examine current therapeutic approaches targeting CAFs. This article underscores the multifarious roles of CAFs within the tumor microenvironment and their potential applications in cancer treatment, highlighting their importance as key targets in overcoming drug resistance and enhancing the efficacy of tumor therapies.


Subject(s)
Cancer-Associated Fibroblasts , Neoplasms , Tumor Microenvironment , Humans , Cancer-Associated Fibroblasts/pathology , Cancer-Associated Fibroblasts/metabolism , Neoplasms/pathology , Neoplasms/therapy , Drug Resistance, Neoplasm , Signal Transduction , Cytokines/metabolism , Disease Progression
2.
Braz J Infect Dis ; 28(2): 103734, 2024.
Article in English | MEDLINE | ID: mdl-38471654

ABSTRACT

BACKGROUND: Understanding the epidemiology of Streptococcus pneumoniae (S. pneumoniae) isolates is important for pneumonia treatment and prevention. This research aimed to explore the epidemiological characteristics of S. pneumoniae isolated from pediatric inpatients and outpatients during the same period. METHODS: S. pneumoniae were isolated from unsterile samples of inpatients and outpatients younger than five years old between March 2013 and February 2014. The serotypes were determined using diagnostic pneumococcal antisera. The resistance of each strain to 13 antibiotics was tested using either the E-test or the disc diffusion method. The Sequence Types (STs) were analyzed via Multilocus Sequence Typing (MLST). RESULTS: The dominant serotypes obtained from inpatients were 19F (32.9 %), 19A (20.7 %), 23F (10.7 %), 6A (10.0 %), and 14 (8.6 %), while those from outpatients were 19F (13.6 %), 23F (12.9 %), 6A (10.0 %), 6B (10.0 %), and 19A (7.9 %). The coverage rates of 13-valent Pneumococcal Conjugate Vaccine (PCV) formulations were high in both groups. The nonsusceptibility to penicillin, cefuroxime, imipenem, erythromycin, and trimethoprim-sulfamethoxazole among the inpatient isolates was 7.1 %, 92.8 %, 65.7 %, 100 %, and 85.0 %, respectively, while that among the outpatient isolates was 0.7 %, 50.0 %, 38.6 %, 96.4 %, and 65.7 %, respectively. There were 45 and 81 STs detected from the pneumococci isolated from inpatients and outpatients, respectively. CC271 was common among both inpatients and outpatients (43.6 % and 14.3 %). CONCLUSIONS: Pneumococcal vaccine-related serotypes are prevalent among both inpatients and outpatients, especially among inpatients, who exhibit more severe antibiotic resistance. Therefore, universal immunization with PCV13 would decrease the hospitalization rate due to S. pneumoniae and the antibiotic resistance rate of S. pneumoniae.


Subject(s)
Anti-Bacterial Agents , Inpatients , Microbial Sensitivity Tests , Multilocus Sequence Typing , Outpatients , Pneumococcal Infections , Serogroup , Streptococcus pneumoniae , Humans , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/isolation & purification , Streptococcus pneumoniae/genetics , Child, Preschool , Outpatients/statistics & numerical data , Infant , Anti-Bacterial Agents/pharmacology , Male , Female , Inpatients/statistics & numerical data , Pneumococcal Infections/microbiology , Pneumococcal Infections/epidemiology , Hospitals, Pediatric , Drug Resistance, Bacterial , Beijing/epidemiology , Serotyping , Pneumococcal Vaccines/immunology
3.
Braz. j. infect. dis ; Braz. j. infect. dis;28(2): 103734, 2024. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1557300

ABSTRACT

Abstract Background Understanding the epidemiology of Streptococcus pneumoniae (S. pneumoniae) isolates is important for pneumonia treatment and prevention. This research aimed to explore the epidemiological characteristics of S. pneumoniae isolated from pediatric inpatients and outpatients during the same period. Methods S. pneumoniae were isolated from unsterile samples of inpatients and outpatients younger than five years old between March 2013 and February 2014. The serotypes were determined using diagnostic pneumococcal antisera. The resistance of each strain to 13 antibiotics was tested using either the E-test or the disc diffusion method. The Sequence Types (STs) were analyzed via Multilocus Sequence Typing (MLST). Results The dominant serotypes obtained from inpatients were 19F (32.9 %), 19A (20.7 %), 23F (10.7 %), 6A (10.0 %), and 14 (8.6 %), while those from outpatients were 19F (13.6 %), 23F (12.9 %), 6A (10.0 %), 6B (10.0 %), and 19A (7.9 %). The coverage rates of 13-valent Pneumococcal Conjugate Vaccine (PCV) formulations were high in both groups. The nonsusceptibility to penicillin, cefuroxime, imipenem, erythromycin, and trimethoprim-sulfamethoxazole among the inpatient isolates was 7.1 %, 92.8 %, 65.7 %, 100 %, and 85.0 %, respectively, while that among the outpatient isolates was 0.7 %, 50.0 %, 38.6 %, 96.4 %, and 65.7 %, respectively. There were 45 and 81 STs detected from the pneumococci isolated from inpatients and outpatients, respectively. CC271 was common among both inpatients and outpatients (43.6 % and 14.3 %). Conclusions Pneumococcal vaccine-related serotypes are prevalent among both inpatients and outpatients, especially among inpatients, who exhibit more severe antibiotic resistance. Therefore, universal immunization with PCV13 would decrease the hospitalization rate due to S. pneumoniae and the antibiotic resistance rate of S. pneumoniae.

4.
Clin Transl Oncol ; 24(7): 1231-1237, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35218523

ABSTRACT

Extensive research is currently being conducted into a variety of bio-inspired biomimetic nanoparticles (NPs) with new cell simulation functions across the fields of materials science, chemistry, biology, physics, and engineering. Cells such as erythrocytes, platelets, and stem cells have been engineered as new drug carriers. The platelet-derived drug delivery system, which is a new targeted drug delivery system (TDDS), can effectively navigate the blood circulatory system and interact with the complex tumor microenvironment; it appears to outperform traditional anticancer drugs; hence, it has attracted considerable research interest. In this review, we describe innovative studies and outline the latest progress regarding the use of platelets as tumor targeting and drug delivery vehicles; we also highlight opportunities and challenges relevant to the manufacture of tumor-related platelet TDDSs.


Subject(s)
Nanoparticles , Neoplasms , Blood Platelets , Drug Carriers/therapeutic use , Drug Delivery Systems , Humans , Neoplasms/drug therapy , Tumor Microenvironment
5.
Acta Cir Bras ; 36(8): e360802, 2021.
Article in English | MEDLINE | ID: mdl-34644770

ABSTRACT

PURPOSE: To evaluate the influence of atractylenolide (Atr) III on sepsis-induced lung damage. METHODS: We constructed a mouse sepsis model through cecal ligation and puncture. These mice were allocated to the normal, sepsis, sepsis + Atr III-L (2 mg/kg), as well as Atr III-H (8 mg/kg) group. Lung injury and pulmonary fibrosis were accessed via hematoxylin-eosin (HE) and Masson's staining. We used terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and flow cytometry for detecting sepsis-induced lung cell apoptosis. The contents of the inflammatory cytokines in lung tissue were measured via enzyme-linked immunosorbent assay (ELISA). RESULTS: Atr III-H did not only reduce sepsis-induced lung injury and apoptosis level, but also curbed the secretion of inflammatory factors. Atr III-H substantially ameliorated lung function and raised Bcl-2 expression. Atr III-H eased the pulmonary fibrosis damage and Bax, caspase-3, Vanin-1 (VNN1), as well as Forkhead Box Protein O1 (FoxO1) expression. CONCLUSIONS: Atr III alleviates sepsis-mediated lung injury via inhibition of FoxO1 and VNN1 protein.


Subject(s)
Amidohydrolases/antagonists & inhibitors , Forkhead Box Protein O1/antagonists & inhibitors , Lung Injury , Sepsis , Sesquiterpenes , Animals , Apoptosis , GPI-Linked Proteins/antagonists & inhibitors , Lactones , Mice , Sepsis/complications , Sepsis/drug therapy , Sesquiterpenes/pharmacology
6.
Acta cir. bras ; Acta cir. bras;36(8): e360802, 2021. graf
Article in English | LILACS, VETINDEX | ID: biblio-1339011

ABSTRACT

ABSTRACT Purpose: To evaluate the influence of atractylenolide (Atr) III on sepsis-induced lung damage. Methods: We constructed a mouse sepsis model through cecal ligation and puncture. These mice were allocated to the normal, sepsis, sepsis + Atr III-L (2 mg/kg), as well as Atr III-H (8 mg/kg) group. Lung injury and pulmonary fibrosis were accessed via hematoxylin-eosin (HE) and Masson's staining. We used terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and flow cytometry for detecting sepsis-induced lung cell apoptosis. The contents of the inflammatory cytokines in lung tissue were measured via enzyme-linked immunosorbent assay (ELISA). Results: Atr III-H did not only reduce sepsis-induced lung injury and apoptosis level, but also curbed the secretion of inflammatory factors. Atr III-H substantially ameliorated lung function and raised Bcl-2 expression. Atr III-H eased the pulmonary fibrosis damage and Bax, caspase-3, Vanin-1 (VNN1), as well as Forkhead Box Protein O1 (FoxO1) expression. Conclusions: Atr III alleviates sepsis-mediated lung injury via inhibition of FoxO1 and VNN1 protein.


Subject(s)
Animals , Mice , Sesquiterpenes/pharmacology , Sepsis/complications , Sepsis/drug therapy , Lung Injury , Forkhead Box Protein O1/antagonists & inhibitors , Amidohydrolases/antagonists & inhibitors , Apoptosis , GPI-Linked Proteins/antagonists & inhibitors , Lactones
7.
Braz J Microbiol ; 51(2): 665-672, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31797324

ABSTRACT

OBJECTIVES: This study aimed to review and report the serotype distribution and antimicrobial resistance patterns of invasive pneumococcal disease (IPD) isolates, as this information is important for policy making since China has not adopted any pneumococcal vaccines in the national immunization schedule. METHODS: A systematic review of the published literature from January 2000 to December 2018 was performed to identify articles that describe the serotype and/or antimicrobial resistance patterns of IPD cases in children in mainland China. Analysis of the extracted data was performed with the Microsoft Excel spreadsheet program. The percentage of the serotypes was calculated by dividing the number of isolates for each serotype with the total number of isolates included in all the studies. The theoretical impact of the vaccine was estimated by calculating the percentage of isolates that exhibited the serotypes included in the vaccines. The prevalence of antimicrobial resistance was defined as the number of isolates that were resistant divided by the total number of isolates tested for resistance to the specific antimicrobial agent. RESULTS: Forty-two articles were screened in the preliminary search, of which sixteen fulfilled inclusion criteria and were included in the final analysis. The predominant serotypes were 19A, 19F, 14, 23F, and 6B, and the estimated impact of PCV13 was 90.4%. The isolates exhibited a high frequency of resistance to cefuroxime, cefaclor, and erythromycin. CONCLUSIONS: It is necessary for Chinese children to receive PCV13. Clinical workers should pay attention to the high frequency of resistance to antimicrobial agents.


Subject(s)
Drug Resistance, Bacterial , Pneumococcal Infections/microbiology , Anti-Bacterial Agents/pharmacology , Child , Child Health , China/epidemiology , Humans , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines/administration & dosage , Prevalence , Serogroup , Streptococcus pneumoniae/drug effects
8.
Braz. J. Microbiol. ; 49(4): 891-899, Oct.-Dec. 2018. ilus, tab, graf
Article in English | VETINDEX | ID: vti-738173

ABSTRACT

This study examined the antimicrobial susceptibility patterns and clonal complex (CC) characteristics of serogroup 6 Streptococcus pneumoniae isolates collected from children in Beijing, China, between 1997 and 2016. Serotypes were determined using the Quellung reaction, and the antimicrobial susceptibility profiles of the isolates were determined using the disc-diffusion method or by E-test. Sequence types (STs) were assigned based on multilocus sequence typing. A total of 250 isolates were examined, with 55.2%, 30.0%, 12.8%, and 2.0% of isolates identified as serotypes 6A, 6B, 6C, and 6D, respectively. All of the isolates were susceptible to levofloxacin and vancomycin, and the non-suceptibitility rate to penicillin was 41.6%. Eighty-two distinct STs, assigned to 13 CCs and 28 singletons, were identified. CC982 was the most prevalent CC amongst serotype 6A isolates (34%), followed by CC9789 and CC3173. Amongst serotype 6B isolates, CC90 and CC4542 were the most common, accounting for 25.3% and 14.7% of isolates respectively. Over the study period, the prevalence of CC982, CC4542, and CC4536 isolates showing susceptibility to penicillin and cefuroxime decreased, and the proportion of CC3173, CC9789, CC855, and CC902 isolates showing non-susceptibility to these two antibiotics increased.(AU)

9.
Braz. j. microbiol ; Braz. j. microbiol;49(4): 891-899, Oct.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-974311

ABSTRACT

ABSTRACT This study examined the antimicrobial susceptibility patterns and clonal complex (CC) characteristics of serogroup 6 Streptococcus pneumoniae isolates collected from children in Beijing, China, between 1997 and 2016. Serotypes were determined using the Quellung reaction, and the antimicrobial susceptibility profiles of the isolates were determined using the disc-diffusion method or by E-test. Sequence types (STs) were assigned based on multilocus sequence typing. A total of 250 isolates were examined, with 55.2%, 30.0%, 12.8%, and 2.0% of isolates identified as serotypes 6A, 6B, 6C, and 6D, respectively. All of the isolates were susceptible to levofloxacin and vancomycin, and the non-suceptibitility rate to penicillin was 41.6%. Eighty-two distinct STs, assigned to 13 CCs and 28 singletons, were identified. CC982 was the most prevalent CC amongst serotype 6A isolates (34%), followed by CC9789 and CC3173. Amongst serotype 6B isolates, CC90 and CC4542 were the most common, accounting for 25.3% and 14.7% of isolates respectively. Over the study period, the prevalence of CC982, CC4542, and CC4536 isolates showing susceptibility to penicillin and cefuroxime decreased, and the proportion of CC3173, CC9789, CC855, and CC902 isolates showing non-susceptibility to these two antibiotics increased.


Subject(s)
Humans , Male , Female , Child, Preschool , Child , Pneumococcal Infections/microbiology , Streptococcus pneumoniae/isolation & purification , Streptococcus pneumoniae/drug effects , Anti-Bacterial Agents/pharmacology , Penicillins , Phylogeny , Pneumococcal Infections/epidemiology , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/genetics , Microbial Sensitivity Tests , China , Multilocus Sequence Typing , Beijing/epidemiology
10.
Braz J Microbiol ; 49(4): 891-899, 2018.
Article in English | MEDLINE | ID: mdl-29606509

ABSTRACT

This study examined the antimicrobial susceptibility patterns and clonal complex (CC) characteristics of serogroup 6 Streptococcus pneumoniae isolates collected from children in Beijing, China, between 1997 and 2016. Serotypes were determined using the Quellung reaction, and the antimicrobial susceptibility profiles of the isolates were determined using the disc-diffusion method or by E-test. Sequence types (STs) were assigned based on multilocus sequence typing. A total of 250 isolates were examined, with 55.2%, 30.0%, 12.8%, and 2.0% of isolates identified as serotypes 6A, 6B, 6C, and 6D, respectively. All of the isolates were susceptible to levofloxacin and vancomycin, and the non-suceptibitility rate to penicillin was 41.6%. Eighty-two distinct STs, assigned to 13 CCs and 28 singletons, were identified. CC982 was the most prevalent CC amongst serotype 6A isolates (34%), followed by CC9789 and CC3173. Amongst serotype 6B isolates, CC90 and CC4542 were the most common, accounting for 25.3% and 14.7% of isolates respectively. Over the study period, the prevalence of CC982, CC4542, and CC4536 isolates showing susceptibility to penicillin and cefuroxime decreased, and the proportion of CC3173, CC9789, CC855, and CC902 isolates showing non-susceptibility to these two antibiotics increased.


Subject(s)
Anti-Bacterial Agents/pharmacology , Pneumococcal Infections/microbiology , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/isolation & purification , Beijing/epidemiology , Child , Child, Preschool , China , Female , Humans , Male , Microbial Sensitivity Tests , Multilocus Sequence Typing , Penicillins , Phylogeny , Pneumococcal Infections/epidemiology , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/genetics
11.
Clinics (Sao Paulo) ; 72(5): 294-304, 2017 May.
Article in English | MEDLINE | ID: mdl-28591342

ABSTRACT

OBJECTIVES:: In this study, we evaluated the association of molecular subtypes, clinical characteristics and pathological types with the prognosis of patients with medulloblastoma. METHODS:: We analyzed forty patients with medulloblastoma who underwent surgical resection at our center between January 2004 and June 2014. Risk factors associated with survival, disease progression and recurrence were analyzed with a univariate Cox regression analysis, and the identified significant risk factors were further analyzed by Kaplan-Meier survival curves. RESULTS:: Factors associated with overall survival included M stage (p=0.014), calcification (p=0.012), postoperative treatment, postoperative Karnofsky Performance Scale (KPS) score (p=0.015), and molecular subtype (p=0.005 for WNT and p=0.008 for SHH). Number of symptoms (p=0.029), M stage (p<0.001), and postoperative radiotherapy (p=0.033) were associated with disease progression. Patients with the WNT or SHH subtype had better survival outcomes than patients with non-WNT/SHH subtypes. Risk factors for disease progression-free survival were symptoms >2 and ≥M1 stage without postoperative radiotherapy. The risk of recurrence increased with advanced M stage. Protective factors for recurrence included M0 stage and a combination of chemotherapy and radiotherapy. CONCLUSION:: We identified the risk factors associated with survival, disease progression and recurrence of medulloblastoma patients. This information is helpful for understanding the prognostic factors related to medulloblastoma.


Subject(s)
Cerebellar Neoplasms , Medulloblastoma , Cerebellar Neoplasms/mortality , Cerebellar Neoplasms/pathology , Cerebellar Neoplasms/therapy , Chemotherapy, Adjuvant , Child, Preschool , Combined Modality Therapy , Disease Progression , Female , Humans , Immunohistochemistry , Kaplan-Meier Estimate , Karnofsky Performance Status , Male , Medulloblastoma/mortality , Medulloblastoma/pathology , Medulloblastoma/therapy , Neoplasm Recurrence, Local , Postoperative Period , Prognosis , Retrospective Studies , Risk Assessment , Risk Factors , Time Factors
12.
Clinics ; Clinics;72(5): 294-304, May 2017. tab, graf
Article in English | LILACS | ID: biblio-840077

ABSTRACT

OBJECTIVES: In this study, we evaluated the association of molecular subtypes, clinical characteristics and pathological types with the prognosis of patients with medulloblastoma. METHODS: We analyzed forty patients with medulloblastoma who underwent surgical resection at our center between January 2004 and June 2014. Risk factors associated with survival, disease progression and recurrence were analyzed with a univariate Cox regression analysis, and the identified significant risk factors were further analyzed by Kaplan-Meier survival curves. RESULTS: Factors associated with overall survival included M stage (p=0.014), calcification (p=0.012), postoperative treatment, postoperative Karnofsky Performance Scale (KPS) score (p=0.015), and molecular subtype (p=0.005 for WNT and p=0.008 for SHH). Number of symptoms (p=0.029), M stage (p<0.001), and postoperative radiotherapy (p=0.033) were associated with disease progression. Patients with the WNT or SHH subtype had better survival outcomes than patients with non-WNT/SHH subtypes. Risk factors for disease progression-free survival were symptoms >2 and ≥M1 stage without postoperative radiotherapy. The risk of recurrence increased with advanced M stage. Protective factors for recurrence included M0 stage and a combination of chemotherapy and radiotherapy. CONCLUSION: We identified the risk factors associated with survival, disease progression and recurrence of medulloblastoma patients. This information is helpful for understanding the prognostic factors related to medulloblastoma.


Subject(s)
Humans , Male , Female , Child, Preschool , Cerebellar Neoplasms , Medulloblastoma , Cerebellar Neoplasms/mortality , Cerebellar Neoplasms/pathology , Cerebellar Neoplasms/therapy , Chemotherapy, Adjuvant , Combined Modality Therapy , Disease Progression , Immunohistochemistry , Kaplan-Meier Estimate , Karnofsky Performance Status , Medulloblastoma/mortality , Medulloblastoma/pathology , Medulloblastoma/therapy , Neoplasm Recurrence, Local , Postoperative Period , Prognosis , Retrospective Studies , Risk Assessment , Risk Factors , Time Factors
13.
Clin Chem Lab Med ; 55(5): 748-754, 2017 May 01.
Article in English | MEDLINE | ID: mdl-27155004

ABSTRACT

BACKGROUND: miRNAs act in diverse biological processes including development, cell growth, apoptosis, and hematopoiesis, suggesting their role in cancer. METHODS: We examined the miRNAs perturbed in CD138+ primary multiple myeloma (MM) cells, using microarray analysis and real-time quantitative PCR (RT-qPCR). Serum miR-4449 expression levels were detected from 71 primary MM patients and 46 healthy controls by RT-qPCR. RESULTS: Our analysis revealed up-regulation of 54 and down-regulation of 28 miRNAs in MM subjects compared to healthy controls. miR-4449 has not been reported in MM. It was found that the relative expression of bone marrow miR-4449 in MM patients (2.14±1.42) was higher than that in healthy controls (0.815±0.165) (U=8, p=0.0093). The relative expression of serum miR-4449 in MM patients (2.11±2.10) was significantly higher than that in healthy controls (0.357±0.235) (U=374, p<0.0001) and was significantly correlated with ß2M, λ light and κ light chain concentration (r=0.480, p=0.0003; r=0.560, p<0.0001; r=0.560, p<0.0001), but not correlated with the lactate dehydrogenase (LDH) concentration (r=0.247, p=0.0611). The area under the curve (AUC) of the receiver-operating characteristics (ROC) curve of serum miR-4449 was 0.885 (95% CI, 0.826-0.945), which is higher than for other markers. Combining miR-4449, λ light chain, and ß2M together, the sensitivity was highest compared with λ light chain or ß2M alone, or combined. CONCLUSIONS: The expression levels of serum miR-4449 in MM patients were significantly higher than in healthy controls, suggesting that it may prove to be useful in the auxiliary diagnosis of MM.


Subject(s)
Biomarkers, Tumor/blood , Biomarkers, Tumor/genetics , MicroRNAs/blood , MicroRNAs/genetics , Multiple Myeloma/blood , Multiple Myeloma/genetics , Aged , Aged, 80 and over , Case-Control Studies , Female , Gene Expression Regulation, Neoplastic , Humans , Immunoglobulin lambda-Chains/blood , Male , Middle Aged
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(8): 2164-9, 2015 Aug.
Article in Chinese | MEDLINE | ID: mdl-26672286

ABSTRACT

Infrared spectra of ambers from Baltic, Dominica and Myanmar are obtained by Specular Reflection and KBr Pellet Transmission Methods. Although the infrared spectra of these ambers present similar features for ambers from different locations, refined differences in location and intensity of absorption peaks could be identified among them. Between 3000 and 2800 cm(-1), two obvious bands with a weak shoulder peak are seen in the Baltic amber spectrum, whereas there are two bands in the Dominica's and three bands in the Myanmar's. In region of 1740~1690 cm(-1), one band appears at 1732 cm(-1) in the spectra of the Baltic amber sample, distinctly different from those of the Dominican and Myanmar ambers which have a doublet at 1730 and 1695 cm(-1). For the Dominican amber, the intensity of 1730 cm(-1) is much stronger than that of 1695 cm(-1), being contrary to the spectra of the Myanmar amber, whose intensity of 1730 cm(-1) is weaker than that of 1695 cm(-1). Within region of 1300~1000 cm(-1), Baltic amber can be distinguished from other two origin ambers by a horizontal shoulder, often called "Baltic shoulder", with a definite band at 1163 cm(-1). Spectra of the Dominican amber show a unique band at 1240 cm(-1), while spectra of the Myanmar amber have a triplet at 1224, 1130 or 1154 cm(-1) and 1033 cm(-1), like "wave of mountain" altogether. Ratios of absorption intensity of 1381 vs. 1456 cm(-1) are about 0.9, 0.8 and 0.7 respectively for the Baltic, Dominican and Myanmar ambers. These differences of absorption spectra could be used as the identifiable characteristics corresponding to the ambers locality. The correlation between the ambers' infrared spectra and localities is probably due to their age, plant provenance and geological environment indivadually. On the basis of presence and intensity of the bands attributed to exocyclic methylene groups, it is suggested that the Myanmar amber formed earliest, followed by Baltic and then the youngest Dominican. These finding reveals that infrared spectroscopy may have significance for identifing amber locality, and thus potentially have archeological implications in determining source of some ancient ambers.

20.
Clin Exp Ophthalmol ; 39(8): 729-33, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22050561

ABSTRACT

BACKGROUND: To evaluate a method for treating uncorrected refractive error in adults in the developing world. DESIGN: Prospective, cross-sectional study in outpatient community health centres. PARTICIPANTS: Eight hundred and forty subjects aged 18 and older from rural villages in Haiti and Belize. METHODS: Undilated refractive error screening exams were conducted over a 5-day period in rural Haiti and Belize using portable autorefractors. Isometropic, spherical, ready-made spectacles were provided to patients with bilateral refractive error, astigmatism ≤ 1 dioptre in each eye and visual acuity worse than 6/9 in each eye. Visual acuity was measured with and without corrective spectacles. MAIN OUTCOME MEASURES: The mean visual improvement and median final visual acuity after treatment with ready-made glasses. RESULTS: Eight hundred and forty patients aged 18 and older were screened with autorefractors. One hundred and eighty-nine subjects (22.5%) were found to have visually significant bilateral refractive error. Fifty-eight per cent (110/189) of these patients met criteria for treatment with ready-made spectacles. Visual acuity improved an average of 4.2 lines in the better eye and 4.1 lines in the worse eye with corrective glasses. The median visual acuity in the better eye was 6/6 after treatment. CONCLUSION: Autorefractors and ready-made spectacles allow for effective treatment of uncorrected refractive error in adults in the developing world.


Subject(s)
Developing Countries , Eyeglasses , Refraction, Ocular , Refractive Errors/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Belize/epidemiology , Cross-Sectional Studies , Equipment Design , Female , Follow-Up Studies , Haiti/epidemiology , Humans , Male , Middle Aged , Morbidity/trends , Outpatients , Prospective Studies , Refractive Errors/epidemiology , Refractive Errors/physiopathology , Treatment Outcome , Visual Acuity , Young Adult
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