[Analysis on the secondary attack rates of SARS-CoV-2 Omicron variant and the associated factors]

Objective: To evaluate the secondary attack rates of the SARS-CoV-2 Omicron variant and the associated factors. Methods: A total of 328 primary cases and 40 146 close contacts of the SARS-CoV-2 Omicron variant routinely detected in local areas of Jiangsu Province from February to April 2022 were selected in this study, and those with positive nucleic acid test results during 7 days of centralized isolation medical observation were defined as secondary cases. The demographic information and clinical characteristics were collected, and the secondary attack rate (SAR) and the associated factors were analyzed by using a multivariate logistic regression model. Results: A total of 1 285 secondary cases of close contacts were reported from 328 primary cases, with a SAR of 3.2% (95%CI: 3.0%-3.4%). Among the 328 primary cases, males accounted for 61.9% (203 cases), with the median age (Q1, Q3) of 38.5 (27, 51) years old. Among the 1 285 secondary cases, males accounted for 59.1% (759 cases), with the median age (Q1, Q3) of 34 (17, 52) years old. The multivariate logistic regression model showed that the higher SAR was observed in the primary male cases (OR=1.632, 95%CI: 1.418-1.877), younger than 20 years old (OR=1.766, 95%CI: 1.506-2.072),≥60 years old (OR=1.869, 95%CI: 1.476-2.365), infected with the BA.2 strain branch (OR=2.906, 95%CI: 2.388-3.537), the confirmed common cases (OR=2.572, 95%CI: 2.036-3.249), and confirmed mild cases (OR=1.717, 95%CI: 1.486-1.985). Meanwhile, the higher SAR was observed in the close contacts younger than 20 years old (OR=2.604, 95%CI: 2.250-3.015),≥60 years old (OR=1.287, 95%CI: 1.052-1.573) and exposure for co-residence (OR=27.854, 95%CI: 23.470-33.057). Conclusion: The sex and age of the primary case of the Omicron variant, the branch of the infected strain, case severity of the primary case, as well as the age and contact mode of close contacts are the associated factors of SAR.

Engineered non-covalent π interactions as key elements for chiral recognition

Molecular recognition and self-assembly are often mediated by intermolecular forces involving aromatic π-systems. Despite the ubiquity of such interactions in biological systems and in the design of functional materials, the elusive nature of aromatic π interaction results in that they have been seldom used as a design element for promoting challenging chemical reactions. Described here is a well-engineered catalytic system into which non-covalent π interactions are directly incorporated. Enabled by a lone pair-π interaction and a π-π stacking interaction operating collectively, efficient chiral recognition is successfully achieved in the long-pursued dihydroxylation-based kinetic resolution. Density functional theory calculations shed light on the crucial role played by the lone pair-π interaction between the carbonyl oxygen of the cinchona alkaloid ligand and the electron-deficient phthalazine π moiety of the substrate in the stereoselectivity-determining transition states. This discovery serves as a proof-of-principle example showing how the weak non-covalent π interactions, if ingeniously designed, could be a powerful guide in attaining highly enantioselective catalysis.

Non-covalent π interactions have been rarely used as a design element for promoting chemical reactions. Here the authors report a Sharpless asymmetric dihydroxylation (SAD)-based kinetic resolution in which a-priori-designed non-covalent forces play a central role in differentiating the enantiomeric substrates.

Nickel-catalyzed multicomponent reaction of dinitriles and hydrazine hydrochlorides with boronic acids: access to 1,3-diaryl-1H-pyrazol-5-amines and 4,5-dihydropyridazin-3(2H)-ones

Developing efficient methods to accommodate azaheterocycles has been the hotspot field in organic synthesis. Herein, we disclose a facile and expeditious avenue to synthesize 1,3-diaryl-1H-pyrazol-5-amines and 4,5-dihydropyridazin-3(2H)-ones via nickel-catalyzed addition,...

Simultaneous Kinetic Resolution and Asymmetric Induction within a Borrowing Hydrogen Cascade Mediated by a Single Catalyst

The mechanistic uniqueness and versatility of borrowing hydrogen catalysis provides an opportunity to investigate the controllability of a cascade reaction, and more importantly, to realize either one or both of chiral recognition and chiral induction simultaneously. Here we report that, in a borrowing hydrogen cascade starting from racemic allylic alcohols, one of the enantiomers could be kinetically resolved, while the other enantiomer could be purposely converted to various targeted products, including α,β-unsaturated ketones, β-functionalized ketones and γ-functionalized alcohols. By employing a robust Ru-catalyst, both kinetic resolution and asymmetric induction were achieved with remarkable levels of efficiency and enantioselectivity. Density functional theory (DFT) calculations suggest that corresponding catalyst-substrate π-π interactions are pivotal to realize the observed stereochemical diversity.

Three Novel Structural Variations at MHC and IL12B Predisposing to Psoriasis

BACKGROUND

Structural variations (SVs, defined as DNA variants ≥50 bp) have been associated with various complex human diseases. However, research to screen the whole genome for SVs predisposing to psoriasis is still lacking.

OBJECTIVES

This study aimed to investigate the association of SVs and psoriasis.

METHODS

We performed a genome-wide screen on SVs using an imputation method on 5 independent cohorts with 45,386 subjects from the Chinese Han population. Fine mapping analysis, genetic interaction analysis and RNA expression analysis were conducted to explore the mechanism of SVs.

RESULTS

We obtained 4,535 SVs in total and identified 2 novel deletions (esv3608550, OR=2.73, P<2.00×10^-308 ; esv3608542, OR=0.47, P=7.40×10^-28 ) at 6q21.33 (MHC), 1 novel Alu element insertion (esv3607339, OR=1.22, P=1.18×10^-35 ) at 5q33.3 (IL12B), and confirmed 1 previously reported deletion (esv3587563, OR=1.30, P=9.52×10^-60 ) at 1q21.2 (LCE) for psoriasis. Fine mapping analysis including SNPs and small Insertions/Deletions (InDels) revealed that esv3608550 and esv3608542 were independently associated with psoriasis, and a novel independent SNP (rs9378188, OR=1.65, P=3.46×10^-38 ) was identified at 6q21.33. By genetic interaction analysis and RNA expression analysis, we speculate that the association of 2 deletions at 6q21.33 with psoriasis might relate to their influence on the expression of HLA-C.

CONCLUSIONS

Our study constructed the most comprehensive SV map for psoriasis thus far and enriched the genetic architecture and pathogenesis of psoriasis as well as highlighted the nonnegligible impact of SVs on complex diseases.

[Luteolin has a significant protective effect against cadmium-induced injury in lung epithelial Beas-2B cells]

OBJECTIVE

To investigate the protective effect of luteolin against cadmium (Cd)-induced injury in human lung epithelial Beas-2B cells.

OBJECTIVE

Beas-2B cells were treated with different concentrations of luteolin (0-160 μmol/L) or Cd (0-40 μmol/L) for 24 h, and the cell viability was examined using MTT assay. After treatment with luteolin (0.25, 0.5 and 0.75 μmol/L) with or without Cd (5 μmol/L) for 24 h, the cells were examined for viability, lactate dehydrogenase (LDH) activity and morphological changes of the cell nuclei using Hoechst fluorescent staining. The levels of ROS, SOD, GSH and MDA in the treated cells were detected, and the expression levels of Akt, p-Akt and nuclear factor E2-related factor 2 (Nrf2) proteins were determined using Western blotting.

OBJECTIVE

Luteolin within the concentration range of 0-80 μmol/L did not significantly affect the survival rate of Beas-2B cells (P>0.05), but Cd at 5 μmol/L significantly decreased the cell viability (P < 0.05) with an IC₅₀ of 24.6 μmol/L. In Cd-treated cells, treatment with luteolin significantly mitigated the decrease of cell viability, reduced LDH release and cell apoptosis, enhanced SOD activity and GSH content, and inhibited the production of MDA and ROS (all P < 0.05). Luteolin also significantly up-regulated the expression levels of p-Akt and Nrf2 protein in Cd-treated Beas-2B cells (P < 0.05).

OBJECTIVE

Luteolin has a significant protective effect against Cd-induced injury in Beas-2B cells, and the effects are probably mediated, at least in part, by promoting the activation of Akt and Nrf2.

Ni-catalyzed cascade coupling reactions: synthesis and thermally-activated delayed fluorescence characterization of quinazolinone derivatives

A nickel-catalyzed cascade coupling of 2-(2-(arylcarbonyl)-4-oxoquinazolin-3(4H)-yl)acetonitrile and arylboronic acid for the synthesis of pyrazino-fused quinazolinones has been developed. The TADF effect of 3a in the solid-state was investigated.

LINC00963 predicts poor prognosis and promotes esophageal cancer cells invasion via targeting miR-214-5p/RAB14 axis

OBJECTIVE

To explore the roles and underlying mechanism of LINC00963 in esophageal squamous cell carcinoma (ESCC) progression.

PATIENTS AND METHODS

Quantitative Real Time-PCR (qRT-PCR) was used to detect LINC00963 expression in ESCC tissues. EdU, colony formation, and transwell invasion assays were used to detect the proliferation and metastasis ability of ESCC, respectively. The correlation between LINC00963 and miR-214-5p in ESCC was confirmed by a Luciferase reporter and RIP assays.

RESULTS

LINC00963 expression was significantly increased in ESCC tissues and correlated with advanced TNM stage, metastasis, and poor prognosis. The knockdown of LINC00963 expression reduced ESCC cells proliferation, invasion in vitro, and reduced tumor growth in vivo. In mechanism, LINC00963 served as a sponge for miR-214-5p in ESCC progression. In addition, miR-214-5p could bind to RAB14 and regulate its expression.

CONCLUSIONS

LINC00963 might promote ESCC cells proliferation and invasion via regulating the miR-214-5p/RAB14 axis and it might serve as a therapeutic target for ESCC treatment.

Genome-wide Analyses Identify a Novel Risk Locus for Nonsyndromic Cleft Palate

The 3 major subphenotypes observed in patients with nonsyndromic orofacial clefts (NSOFCs) are nonsyndromic cleft lip only (NSCLO), nonsyndromic cleft lip with palate (NSCLP), and nonsyndromic cleft palate only (NSCPO). However, the genetic architecture underlying NSCPO is largely unknown. Here we performed a 2-stage genome-wide association study (GWAS) on NSCPO and replication analyses of selected variants in other NSOFCs from the Chinese Han population. We identified a novel locus (15q24.3) and a known locus (1q32.2) where variants in or near the gene reached genome-wide significance (2.80 × 10^-13 < P < 1.72 × 10^-08) in a test for association with NSCPO in a case-control design. Although a variant from 15q24.3 was found to be significantly associated with both NSCPO and NSCLP, the direction of estimated effects on risk were opposite. Our functional annotation of the risk alleles within 15q24.3 coupled with previously established roles of the candidate genes within identified risk loci in periderm development, embryonic patterning, and/or regulation of cellular processes supports their involvement in palate development and the pathogenesis of cleft palate. Our study advances the understanding of the genetic basis of NSOFCs and provides novel insights into the pathogenesis of NSCPO.

Palladium-Catalyzed Cascade Reactions of δ-Ketonitriles with Arylboronic Acids: Synthesis of Pyridines

This study presents the first example of the Pd-catalyzed cascade reactions of 5-oxohexanenitrile with arylboronic acids, affording important synthon 2-methylpyridines that can be further translated through C(sp³)-H functionalization to construct pyridine derivatives. Furthermore, this chemistry allows 5-oxo-5-arylpentanenitrile to react with arylboronic acids to provide unsymmetrical 2,6-diarylpyridines. This protocol paves the way for the practical and atom economical syntheses of valuable pyridines with broad functional groups in moderate to excellent yields under mild conditions.

Nickel(ii)-catalyzed C–C, N–C cascade coupling of ketonitriles into substituted pyrroles and pyridines

The first example of nickel complexes as effectively catalyst to C–C, N–C cascade coupling of ketonitriles with arylboronic acids, affording 2,5-diarylpyrroles and 2,6-diarylpyridines.

Syntheses of Pyrroles, Pyridines, and Ketonitriles via Catalytic Carbopalladation of Dinitriles

The first example of the Pd-catalyzed addition of organoboron reagents to dinitriles, as an efficient means of preparing 2,5-diarylpyrroles and 2,6-diarylpyridines, has been discussed here. Furthermore, the highly selective carbopalladation of dinitriles with organoboron reagents to give long-chain ketonitriles has been developed as well. Based on the broad scope of substrates, excellent functional group tolerance, and use of commercially available substrates, the Pd-catalyzed addition reaction of arylboronic acid and dinitriles is expected to be significant in future synthetic procedures.

Direct halosulfenylation of benzo[b]furans: a metal-free synthesis of 3-halo-2-thiobenzo[b]furans

The first example of the direct halosulfenylation of benzo[b]furans with commercially available disulfides and N-halosuccinimides has been achieved, providing an efficient metal-free synthetic pathway to access diverse 3-halo-2-thiobenzo[b]furans in moderate to excellent yields. In particular, a halogen (e.g., bromo or iodo) substituent on the benzo[b]furan ring is amenable for further synthetic elaborations thereby broadening the diversity of the products.

Capacity of a body shape index and body roundness index to identify diabetes mellitus in Han Chinese people in Northeast China: a cross-sectional study

AIM

To assess the capacity of a body shape index and body roundness index to identify people with diabetes mellitus and those with prediabetes, and to determine whether a body shape index and/or body roundness index is superior to the traditional overall adiposity index, BMI, in Han Chinese people in Northeast China.

METHODS

A total of 15 078 participants were enrolled from Jilin province in 2012 using a multi-stage stratified random cluster sampling method. Demographic data were collected, and anthropometric indices and biochemical indices were measured. Receiver-operating characteristic curves were used to compare the validity of each anthropometric index, and the area under the receiver-operating characteristic curve was calculated for each anthropometric index.

RESULTS

Body roundness index had the highest areas under the receiver-operating curve for prediabetes, diagnosed diabetes and undiagnosed diabetes in both men and women (all P<0.01). The optimum threshold values for body roundness index for prediabetes, undiagnosed diabetes and diagnosed diabetes, respectively, were 2.8, 3.7 and 3.3 in men, and 3.4, 3.8 and 3.6 in women. The cumulative proportions of prediabetes, undiagnosed diabetes and diagnosed diabetes identified by the optimum threshold values of body roundness index were 79.2%, 67.5% and 77.0% (82.3%, 62.5% and 75.3% in men; 74.6%, 74.9% and 78.3% in women), respectively.

CONCLUSIONS

BMI, a body shape index and body roundness index may identify the presence of diabetes. Among the three anthropometric indices, BMI had the weakest association with diabetes. Body roundness index is an alternative index for assessing diabetes in Han Chinese people in Northeast China.

Efficient Approach to Carbinol Derivatives through Palladium-Catalyzed Base-Free Addition of Aryltriolborates to Aldehydes

Palladium-catalyzed base-free addition of aryltriolborates to aldehydes has been developed, leading to a wide range of carbinol derivatives in good to excellent yields. The efficiency of this transformation was demonstrated by compatibility with a wide range of functional groups. The present synthetic route to carbinol derivatives could be readily scaled up to gram quantity without difficulty. Thus, this method represents a simple and practical procedure to access carbinol derivatives.

Recent advances in management of tuberculosis in infants

The global tuberculosis (TB) incidence estimated by WHO is found to be 8.6 million people. Moreover, the highest TB burden worldwide is found in Asian and African countries. The disease is more prevalent in infants due to their immature immune systems. Despite this, the available diagnostic tools pose a challenge due to paucibacillary nature of the disease and difficulty in obtaining specimens. The present review article discusses the important and upcoming advancements in the management of above pathological state. The article will enlighten the new vaccinations for TB in the pipeline. Moreover, new upcoming approaches involving system biology and gene expression profiling for efficient supervision of the disease will also be highlighted.

Magnesium sulfate micro air pump suction for bronchiolitis treatment in infants under two years old

OBJECTIVE

To investigate the efficiency, clinical effects and nursing methods related to the use of magnesium sulfate micro air pump suction for treating infants under two years old suffering from bronchiolitis.

PATIENTS AND METHODS

From January 2014 to September 2014, ninety-six infants with capillary bronchitis were enrolled. Patients were randomly divided into two groups: experimental group (n=49) and control group (n=47). All patients went through conventional anti-inflammatory therapy. Based on this, infants in the control group were additionally treated with intravenous drip of magnesium sulfate while patients in the experimental group were treated with magnesium sulfate micro air pump suction. We recorded all changes in blood gas and clinical scores, the residence time of symptoms and signs of bronchiolitis, and hospitalization time. Results obtained on clinical effects and adverse reactions were compared and analyzed.

RESULTS

The Variations of PaO2, PaCO2, SaO2 before treatment in both groups did not show any statistically significant differences (p>0.05); while after treatment analyses demonstrated that in both groups we had an increase in PaO2 and SaO2 and a decrease in PaCO2. The increase in PaO2 and SaO2 values were more pronounced while the decrease observed in PaCO2 was more significant in our experimental group. The total effective rate was significantly higher while the total adverse reaction rate, the resolution time of clinical symptoms and hospitalization time were significantly lower in our experimental group.

CONCLUSIONS

Magnesium sulfate micro air pump suction was safe and effective in treating with bronchiolitis of infants below 2 years old, and its adverse reaction rate was low, nursing procedure was simple, and nursing difficulty level was low.

Pedobarography - a novel screening tool for diabetic peripheral neuropathy?

AIM

To investigate the diagnostic significance of foot plantar pressure distribution abnormalities in patients with diabetic peripheral neuropathy (DPN).

PATIENTS AND METHODS

A total of 107 patients were divided into normal control (28 participants, 56 feet), non-DPN (56 patients, 112 feet), and DPN groups (23 patients, 46 feet). Foot plantar pressure was measured while patients walked at a constant speed over a flat floor using F-Scan pressure insoles. Recordings of six middle strides were averaged to evaluate the characteristics of foot plantar pressure distribution.

RESULTS

Compared with the normal group, the time of contact (TOC) was longer in non-DPN (p < 0.05) and DPN groups (p < 0.01). The foot to floor force-time integral (FTI) was increased in DPN group (p < 0.01). The forefoot plantar force ratio increased in non-DPN and DPN patients (p < 0.05). Moreover, in DPN patients, the ratio of lateral foot plantar force increased (p < 0.05). The examination of the correlations between biomechanical parameters of the foot plantar and electrophysiological parameters of the lower limbs showed foot plantar biomechanical abnormalities correlated with abnormal sensory conduction of the sural nerve and motor conduction of the common peroneal nerve. Receiver operating characteristic (ROC) analysis showed the area under FTI curve was 0.714 (p < 0.001).

CONCLUSIONS

The plantar pressure was shifted towards the side of the forefoot in DPN patients. The foot plantar biomechanical changes were closely correlated with lower limb paresthesia and contraction abnormalities of lower-limb extensor muscles. Foot plantar pressure measurement might be used as a screening tool for early diagnosis of DPN.

Asymptomatic brucellosis infection in humans: implications for diagnosis and prevention

Human brucellosis is mainly caused by contact with Brucella-infected animals and their secretions and carcasses. Individuals who are continuously in contact with animals are considered to be at a high risk but only some show symptoms and are diagnosed as cases of brucellosis. Here, we showed that asymptomatic brucellosis infections occur among humans. Asymptomatic infections mainly result from less frequent contact with Brucella and/or contact with low-virulence Brucella. In our study, patients with asymptomatic infection had low antibody titres and different contact patterns. Awareness of asymptomatic infection is important for early diagnosis of brucellosis and prevention of chronic infection.

Characterization of SSU and LSU rRNA genes of three Trypanosoma (Herpetosoma) grosi isolates maintained in Mongolian jirds

Trypanosoma (Herpetosoma) grosi, which naturally parasitizes Apodemus spp., can experimentally infect Mongolian jirds (Meriones unguiculatus). Three isolates from A. agrarius, A. peninsulae, and A. speciosus (named SESUJI, HANTO, and AKHA isolates, respectively) of different geographical origin (AKHA from Japan, and the others from Vladivostok), exhibited different durations of parasitaemia in laboratory jirds (2 weeks for HANTO, and 3 weeks for the others). To assess the genetic background of these T. grosi isolates, their small (SSU) and large subunit (LSU) ribosomal RNA genes (rDNA) were sequenced along with those of 2 other Herpetosoma species from squirrels. The SSU rDNA sequences of these 3 species along with available sequences of 3 other Herpetosoma trypanosomes (T. lewisi, T. musculi and T. microti) seemed to reflect well the phylogenetic relationship of their hosts. Three isolates of T. grosi exhibited base changes at 2-6 positions of 2019-base 18S rDNA, at 5-29 positions of 1817/1818-base 28Salpha rDNA, or 1-5 positions of 1557-1559-base 28Sbeta rDNA, and none was separated from the other 2 isolates by rDNA nucleotide sequences. Since base changes of Herpetosoma trypanosomes at the level of inter- and intra-species might occur frequently in specified rDNA regions, the molecular analysis on these regions of rodent trypanosomes could help species/strain differentiation and systematic revision of Herpetosoma trypanosome species, which must be more abundant than presently known.

[The influence of palatoplasty and tympanotomy on middle ear function in cleft palate patients]

OBJECTIVE

The aim of this study is to explore the influence of palatoplasty and tympanotomy on middle ear function or hearing condition in cleft palate patients.

METHODS

A total of 22 ears with otitis media with effusion in cleft palate patients were inserted with PE tubes, and Pre- and post-operative hearing level and middle ear function in these patients were tested and compared respectively, in order to demonstrate the action of tympanotomy and PE insertion on hearing and middle ear function. Another 38 patients with cleft palate were operated in their early age with the proper operation method, and pre- and post-operative middle ear function were examined and compared to show the influence of the operation on the middle ear function.

RESULTS

PE Tube insertion and tympanotomy changed the pressure condition of middle ear cavity and raised the hearing level about 17 dB in the middle-ear-diseased cleft palate patients, and patients with palatoplasty did not show obvious changes in middle ear function in the short-term trail.

CONCLUSION

Early and active tympanotomy do help in improving the function of the middle ear, and it is suggested to improve patients' hearing and middle ear function as early as possible. Palatoplasty did not affect the function of middle ear.

[The influence of the hamulotome and interplatal incision on the middle ear function]

OBJECTIVE

The aim of this study is to explore the effect of hamulotome on the eustachian tube function and verify the function of the tensor veli palatili muscle on eustachian tube.

METHODS

Single-sided hamulotome were carried out in the rabbits under the direct visual. And the middle ear cavity mucosa of the rabbits was collected at different intervals and dyed with PAS and PH to observe the middle ear changes under microscope.

RESULTS

Middle ear function changed obviously after the hamulotome, with increase in globular cells, submucosal edema and inflammatory cells. And mucin was not found in several cavities.

CONCLUSION

Hamulotome do affect on the middle ear function and should not be damaged in order to protect the middle ear function in some patients.

Observation on the changes of plasma cardionatrion before and after microwave acupuncture in coronary heart disease

This paper reports the therapeutic effect of microwave acupuncture (MWA) and its influence on the plasma level of cardionatrion. Twenty-eight cases with coronary heart disease (CHD) were systemically observed and investigated. Atrial natriuretic polypeptides (ANP) were determined by radioimmunoassay. Plasma level of ANP was elevated, the rising rate being 100%. The therapeutic effect of MWA in the 28 cases with CHD was 85.7%, the ECG improving rate was 82.2%. Effect of MWA was briefly discussed. The authors consider that the therapeutic effect of MWA in the treatment of CHD could be ascertained, and the measurement of plasma ANP concentration is a useful method and an objective parameter for further research.

A study of calcium ion-selective PVC membrane electrode based on neutral carrier N,n,n',n'-tetracyclo-3-oxapentanediamide (correction of oxapetanediamide)

A calcium ion-selective PVC membrane electrode based on neutral carrier n,n,n',n'-tetracyclohexyl-3-oxapetanediamide, using di-(2-ethylhexyl)phthalate as the plasticizer and potassium tetrakis (4-chlorophenyl) borate as the additive is reported in this paper. The ion selective membrane consists of 1 wt% of the Ca2+ selective ligand, 65 wt% of the plasticizer, 1 wt% of the additive and 33 wt% of poly (vinyl chloride) powder. The electrode has the linear response range of 2.0 x 10(-7)-10(-1) mol/L with the Nernstian slope of 28 mV/decade at 25 degrees C and the detection limit of 2.0 x 10(-8) mol/L. The response time of the calcium ion-selective electrode is as the concentration of calcium ion is rapidly shifted from 10(-5) to 10(-4) mol/L. The potential stability and reproducibility are good. The free calcium in blood serum was determined by the calcium ion-selective electrode with satisfactory results.

Age-related cataract in the Tibet Eye Study

The Tibet Eye Study was designed to estimate the prevalence of age-related cataract in Duilong-Deqing County, west of Lhasa, China (altitude, 4000 m). Previous reports have suggested an unusually high prevalence of age-related cataract in Tibet. A two-stage probability sample of persons aged 20 years or older from the 35 townships of the county targeted 2884 persons for inclusion in the study; 2665 (92.4%) were examined. Age-related cataract was diagnosed when (1) visual acuity was worse than 6/12 (20/40) because of nuclear or cortical (including posterior subcapsular) opacities, or (2) aphakia associated with a history of age-related cataract was present in either eye. The prevalence of age-related cataract among persons aged 20 to 39 years was 0.2%; among persons 40 years old or older, the prevalence was 11.8%. Cortical cataracts were by far the most common type of cataract diagnosed. Age- and sex-adjusted prevalence in Tibet was 60% higher than the prevalence in a similar, previously conducted study of 6951 person in Shunyi County, northeast of Beijing (altitude, 50 m). A second, independent slit-lamp classification of lens status was conducted in the Tibet Eye Study using standard photographs previously described. Age-specific cataract prevalence was similar with the two examination techniques. Results from the Tibet Eye Study support previous suggestions of a high prevalence of age-related cataract in Tibet.