Reproductive health risks and HIV infection vulnerability of hostesses in metropolitan areas, China: a qualitative study

In this paper, we describe sex-related health risks among hostesses in two metropolises in China based on data obtained from in-depth interviews. The data show that hostesses, many engaging in commercial sex, are vulnerable to HIV infection, unwanted pregnancies and reproductive tract infections. Nevertheless, many obstacles still are present that hinder them from engaging in safe sex. The findings from our study illustrate the need for targeted interventions in order to improve reproductive health and promote safe sex among this group.

First Report of Boll Rot of Cotton Caused by Pantoea agglomerans in China

Since the summer of 2006, bacterial boll rot of cotton has been observed on fruits of 'Xinluzao 31' (Xinluzao 6 × Acala) in Xinjiang Province. It resulted in as much as 20% yield loss in several fields. Symptoms do not appear on the outer carpel. In the infected cotton bolls, fibers do not mature completely and seed tissue exhibits brown necrotic coloration. Lint and seeds from 24 surface-disinfested cotton bolls were triturated and plated onto King's medium B (KB). Plates were incubated at 28°C for 48 h. Forty eight strains with yellow pigmentation on KB were characterized. All were nonfluorescent on KB, gram negative, facultatively anaerobic, unable to produce indole from tryptophan, able to reduce nitrate to nitrite, and produce acid from glucose, cellobiose, lactose, melibiose, and melonate. In addition, 16S rDNA in seven strains was amplified with universal primers (1). The PCR products were cloned into pGEM-T easy vector and sequenced. A BLAST search of the seven sequences against the GenBank nucleotide library indicated 100% identity with the 16S rDNA sequence of Enterobacter agglomerans strain A80. Then an additional primer pair, pagF and pagR (3), was used for more specific amplification of Pantoea agglomerans 16S rDNA, which resulted in single highly specific fragments of approximately 1 kb. On the basis of morphological, physiological, biochemical characteristics, and 16S rRNA gene sequence analysis, we identified the bacterium to be P. agglomerans. To confirm pathogenicity, cell suspensions (1 × 10⁸ CFU/ml) of eight representative strains were used to inoculate cotton at peak bolling stage in the field. Cell suspensions, or water as the control, were applied to stigma scars, wall sutures, and scratch wounds on bracts, calyxes, and bolls. Alternatively, a needle was used to puncture through a drop of suspension placed on the boll wall suture and bracts. At least 20 bolls or flowers were inoculated with each bacterial strain per inoculation method. Infection occurred only when bacterial injections breached the endocarp of the boll either through the carpel wall or a suture between carpel sections. Disease symptoms developed 1 week postinoculation. The inoculated organism was reisolated from the diseased tissues. P. agglomerans is generally regarded to be a soil saprophyte or leaf epiphyte, but strains can opportunistically infect plants triggering gall formations or human wounds causing septic arthritis. The disease symptoms and pathogen characteristics observed in this study are identical to those reported in the United States (2). To our knowledge, this is the first report of P. agglomerans causing boll rot of cotton in China. References: (1) S. Manulisi and I. Barash. Mol. Plant Pathol. 4:307, 2003. (2) E. G. Medrano et al. J. Appl. Microbiol. 103:436, 2007. (3) S. Vorwerk et al. Agric. For. Entomol. 9:57, 2007.

First Report of Acidovorax avenae subsp. citrulli Infecting Edible Seed Watermelon (Citrullus lanatus var. lanatus) in China

Edible seed watermelon, Citrullus lanatus var. lanatus, is a type of watermelon from which only the seeds are consumed. Between 2003 and 2005, a bacterial disease was discovered on this type of watermelon in several regions of Xinjiang Province in western China, with a diseased area of 40,000 ha. The average disease incidence on fruit and seedlings was approximately 30 and 20%, respectively. Symptoms were most noticeable on fruit. Lesions on the fruit rind were first noticeable as small pinpoint water-soaked areas. As the lesions rapidly enlarged, black, starshaped cracks formed in the rind, and the rind along with the flesh around the spots hardened. If no secondary invaders or saprophytes entered through the cracks, the inside flesh often disintegrated into dry stiff cavities. The fruit with necrotic spots became markedly malformed. The pathogen also infected seedlings. First symptoms on the seedling appeared as dark, water-soaked lesions on the underside and edge of the cotyledons. As the cotyledon expanded, the lesions become necrotic and often extended along the length of the midrib and eventually merged into large, black, withered areas. To determine the causal agent of the disease, 54 bacterial strains were isolated from cotyledons, fruits, or seeds of edible seed watermelon. By spray inoculation, these strains were inoculated onto edible seed watermelon cv. Xinzigua1 at the two-true-leaf stage with bacterial concentrations at 10⁷ CFU/ml. All strains were strongly virulent to cv. Xinzigua1, which is planted in large areas in Xinjiang, by forming many water-soaked spots on cotyledons and true leaves. There were no symptoms in the control that was sprayed with sterile deionized water. Through biological and biochemical characteristics, including Gram reaction and tests for catalase, oxidase, and oxygen requirement, all strains were identified as Acidovorax avenae subsp. citrulli. To verify pathogen identification, specific polymerase chain reaction was also carried out. One set of 16S primers, WFB1/WFB2 for A. avenae subsp. citrulli, was used (1). A single unique band of approximately 360 bp was amplified for all strains tested. To our knowledge, this is the first report of A. avenae subsp. citrulli infecting edible seed watermelon. Reference: (1) R. R. Walcott and R. D. Gitaitis. Plant Dis.84:470, 2000.

Association between the scores on the general health questionnaire-28 and the saliva levels of 3-methoxy-4-hydroxyphenylglycol in normal volunteers

To access the saliva level of 3-methoxy-4-hydroxy-phenylglycol (sMHPG) as an index of mental health in normal volunteers, we investigated the relationship between the sMHPG and the scores on the general health questionnaire-28 (GHQ-28). A total of 270 normal volunteers answered the GHQ-28 and the sMHPG levels were determined. The sMHPG levels in women and men were comparable. There was a significant negative correlation between the social dysfunction score on the GHQ-28 and sMHPG levels in women (P=0.0035), but not in men. Moreover, the sMHPG levels also correlated with the total GHQ-28 score (P=0.0205), the anxiety and the insomnia score (P=0.0306) in women. These data indicate a high social dysfunction score on the GHQ-28 to be associated with a reduced noradrenergic neuronal tone thus possibly reflecting psychomotor retardation in women.

Involvement of the noradrenergic system in performance on a continuous task requiring effortful attention

To determine the effects of noradrenergic neuronal activity on performance in continuous tasks requiring effortful attention, the performance of 23 male students in the Uchida-Kraepelin test (UKT) was examined. The UKT requires continuous arithmetic addition of single-digit figures for 25 min. The relationship of performance with saliva levels of 3-methoxy-4-hydroxyphenylglycol (sMHPG) was analyzed. Saliva samples were taken before, during and after test performance, and sMHPG levels determined by gas chromatography-mass spectrometry. There was no significant change in mean sMHPG as a result of test performance. However, when initial effort was calculated, defined as number of items completed during the 1st min subtracted from the average completed per minute in the 1st and the 2nd halves (blocks) of the test, significant correlations with sMHPG (p = 0.0002 for the 1st block and p < 0.0001 for the 2nd block) were found. Thus the data indicate that noradrenergic neuronal activity affects the performance on continuous tasks requiring effortful attention.

[Study on the fusion expression of FBXO30: a novel member of F-box protein family]

OBJECTIVE

The cDNA sequence of the coding region of FBXO30 (F-box only protein 30), which is a novel member of F-box protein family, was cloned into the mammalian expression vector pEGFP-C2 by non-directional cloning method and introduced into the NIH 3T3 cells by liposome transfection. Observation under the fluorescent microscopy after transfection showed that EGFP (enhanced green fluorescent protein)/FBXO30 was expressed and existed mainly in the cytoplasm. At the same time, the cDNA sequence of the coding region of FBXO30 was cloned into prokaryotic expression vector pGEX-4T-2 by directional cloning strategy. The GST (glutathione S-transferase)/FBXO30 fusion protein was expressed under the induction of IPTG (isopropylthio-beta-D-galactoside) in E. coli. A new band (approximately 65.5 kD) was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Purification of the GST-fused FBXO30 was carried out by affinity chromatography with glutathione sepharose 4B. The fusion expression of FBXO30 indicates that: FBXO30 protein is a cytoplasmic soluble protein, and the stable fusion expression of FBXO30 in the prokaryotic expression system can provide a base for the preparation of the specific antibody of FBXO30 and further functional study of FBXO30.

The mRNA level of the potassium-chloride cotransporter KCC2 covaries with seizure susceptibility in inferior colliculus of the post-ischemic audiogenic seizure-prone rat

Cardiac arrest and resuscitation were used to induce brain damage and susceptibility to sound-triggered seizures in Sprague-Dawley rats. Glucose preloading was used to vary seizure susceptibility. Because loop diuretics can block these seizures, we investigated changes in KCC2, a potassium-chloride cotransporter, in the inferior colliculus - the origin of the seizures. Using polymerase chain reaction (PCR), we found that collicular KCC2 mRNA levels covaried with seizure susceptibility in these animals. Using quantitative PCR, we found that a fivefold increase in collicular KCC2 mRNA levels was associated with a doubling of seizure incidence. A hypothesis linking KCC2 activity to seizure susceptibility is presented.

[A nasopharyngeal carcinoma negatively related EST on 7q32]

To isolate and clone the tumor suppressor gene on chromosomal region 7q32 that corelated with the occurrence of human NPC, we detected the genotype of polymorphic microsatellite markers on 7q32 in 24 nasopharyngeal carcinoma biopsies and matched normal lymphocyte DNA. LOH was found in 30% biopsies. Using differential RT-PCR and Northern hybridization we compared the expression level of 20 EST on 7q32 between NPC cell line HNE1 and primary culture of normal nasopharyngeal epithelial cell, and found AA070437 EST expressed high in primary culture of normal nasopharyngeal epithelial cell, but very low in HNE1. Differential RT-PCR (dRT-PCR) analysis showed that the expression level of AA070437 was lower in 30.7% NPC biopses than in normal cell. Differential PCR (dPCR) showed that allelic loss of AA070437 was observed in 29.1% NPC biopses. This EST is a part of sequence of a new gene compared with GeneBank database. Our results showed that AA070437 EST negatively related with the occurrence of human NPC is a candidate of tumor suppressor gene of NPC on 7q32.

[Simultaneous observation of parameter of intraventricular pressure and energy metabolism in rat hearts using nuclear magnetic resonance]

A technique for simultaneous observation of parameters of intraventricular pressure and energy metabolic status in isovolumic rat hearts was described. The parameters of intraventricular pressure were collected and processed using a computerized monitoring system for heart function, and myocardial energy metabolism was investigated by collecting the 31P NMR spectra. The preparation was stable metabolically and functionally for 2 h under the NMR experimental conditions.

The novel function of the Saccharomyces cerevisiae CBP2 gene as a splicing factor essential to excision of the Saccharomyces douglasii LSU intron in vivo

In the yeast Saccharomyces cerevisiae, the product of the nuclear gene CBP2 is required exclusively for the splicing of the terminal intron of the mitochondrial cytochrome b gene. The homologous gene from the related yeast, Saccharomyces douglasii, has been shown to be essential for respiratory growth in the presence of a wild-type S. douglasii mitochondrial genome and dispensable in the presence of an intronless mitochondrial genome. The two CBP2 genes are functionally interchangeable although the target intron of the S. cerevisiae CBP2 gene is absent from the S. douglasii mitochondrial genome. To determine the function of the CBP2 gene in S. douglasii mitochondrial pre-RNA processing we have constructed and analyzed interspecific hybrid strains between the nuclear genome of S. cerevisiae carrying an inactive CBP2 gene and S. douglasii mitochondrial genomes with different intron contents. We have demonstrated that inactivation of the S. cerevisiae CBP2 gene affects the maturation of the S. douglasii LSU pre-RNA, leading to a respiratory-deficient phenotype in the hybrid strains. We have shown that the CBP2 gene is essential for excision of the S. douglasii LSU intron in vivo and that the gene is dispensable when this intron is deleted or replaced by the S. cerevisiae LSU intron.

Gap junction Cx26 gene modulation by phorbol esters in benign and malignant human mammary cells

Connexin (Cx) 26, a major gap junction protein expressed in mammary epithelial cells, has been considered to be a tumor suppressor gene candidate. This study investigated the molecular mechanism of transcriptional up-regulation of Cx26 by phorbol ester (TPA) in human immortalized MCF-10 mammary epithelial cells and MDA-MB-231 mammary cancer cells. Such up-regulation was mediated through the protein kinase C pathway and could be blocked by the PKC inhibitor, calphostin C. Based on the results of the nuclear run-on assay, there was a TPA-induced increase in the rate of transcriptional initiation. We identified a TPA-induced DNase I hypersensitivity (DH) region approximately 1 kb 5' upstream of the ATG translation starting site. Sequence analysis revealed that this DH region was located in intron 1 and contained two TRE-like TGAT/ATCA elements, two 5'TTCA3' motifs and a 5'AGGAAG3' PEA3 motif. Both TRE-like elements were capable of binding AP1. TPA inducibility of this DH region was seen by the CAT reporter assay and appeared to be direction-dependent suggesting a functional cooperation between PEA3/TTCA and TRE.

[Chemical investigation of genus Hedyotis. II. Isolation and identification of iridoids from Hedyotis chrysotricha]

Many species of genus Hedyotis (Rubiaceae) were used as folk medicine for treatment of cold, inflammation, cancer and etc. in China. The alcoholic extract of the whole plant of H. chrysotricha showed good hepatoprotective effects. From the alcoholic extract ten iridoids were isolated and their structures were elucidated as: asperuloside (1), scandoside methyl ester (2), asperulosidic acid (3), deacetyl asperulosidic acid (4), loganin (5), deacetyl asperuloside (6), acetyl scandoside methyl ester (7), 6 beta-hydroxy-genipin (8) and two new compounds named hedyoside (9) and 6'-acetylasperuloside (10), by means of chemical and spectral methods.

[Studies on the chemical structure of lucyoside R from leaves of Luffa cylindrica roem]

A new pentacyclic triterpenoid saponin, lucyoside R, has been isolated from the leaves of Luffa cylindrica along with lucyoside G. Its stucture was established as 2 alpha, 21 beta-dihydroxyhederagenin-3-O-beta-D-glucopyranoside based on spectral and chemical evidence.

[Smoking behaviour and its influencing factors among cigarette smokers in Beijing]

An investigation was carried out among 6,000 persons aged 15-70 to explore the prevalence of cigarette smoking and its risk factors in urban and suburban areas of Beijing. Results showed that 39.07% of Beijing residents were smokers (58.95% male, 17.42% female) who started smoking at an average age of 19.52% and over 2/3 of them admitted their initiafion of smoking was mainly due to curiosity and pressure from social intercourse. Results of polychotomas regression analysis demonstrated that the risk factors of smoking were related to sex, poor education, unhappy marriage, and lacking of knowledge on the negative health outcome of smoking. It is suggested that the program on smoking of control should be strengthened in Beijing.

[Relationship between syndrome differentiation-typing and expression of platelet-activation molecule CD62P and CD63 on platelets in psoriatic patients]

OBJECTIVE

To understand the relationship between Syndrome Differentiation- Typing and platelet activation in psoriatic patients.

METHODS

Expression of platelet-activation molecules CD62P (alpha-granule membrane glycoprotein) and CD63 (lysosomal integral membrane protein) on platelets from 36 psoriatic patients with Syndrome Differentiation-Typing in TCM and 31 health subjects were investigated by using flow cytometry and specific monoclonal antibodies against activated platelet.

RESULTS

(1) Increased expression of CD62P and CD63 on platelets from psoriatic patients was observed (P < 0.001); (2) The expression of CD62P and CD63 was in following order: The group of Blood Stasis > Blood Dryness > Blood Heat; (3) Compared with the group of Blood Heat, increased expression of CD62P and CD63 was observed in the group of Blood Dryness (P < 0.001); (4) Compared with the group of Blood Dryness, increased expression of CD62P and CD63 was observed in the group of Blood Stasis (P < 0.001).

CONCLUSION

The platelet activation might play an important role in higher blood viscosity, endothelial cell injury, abnormal microcirculation, which was correlated with Blood Stasis, found in psoriasis.

In vitro mutagenesis of the mitochondrial leucyl tRNA synthetase of Saccharomyces cerevisiae shows that the suppressor activity of the mutant proteins is related to the splicing function of the wild-type protein

The NAM2 gene of Saccharomyces cerevisiae encodes the mitochondrial leucyl tRNA synthetase (mLRS), which is necessary for the excision of the fourth intron of the mitochondrial cytb gene (bI4) and the fourth intron of the mitochondrial coxI gene (aI4), as well as for mitochondrial protein synthesis. Some dominant mutant alleles of the gene are able to suppress mutations that inactivate the bI4 maturase, which is essential for the excision of the introns aI4 and bI4. Here we report mutagenesis studies which focus on the splicing and suppressor functions of the protein. Small deletions in the C-terminal region of the protein preferentially reduce the splicing, but not the synthetase activity; and all the C-terminal deletions tested abolish the suppressor activity. Mutations which increase the volume of the residue at position 240 in the wild-type mLRS without introducing a charge, lead to a suppressor activity. The mutant 238C, which is located in the suppressor region, has a reduced synthetase activity and no detectable splicing activity. These data show that the splicing and suppressor functions are linked and that the suppressor activity of the mutant alleles results from a modification of the wild-type splicing activity.

[Influence of different combination of mental activity and respiratory cycle on heart rate variability]

By means of spectral analysis of P-R interval, different characteristics of heart rate variability in different form of respiratory exercise was observed. The results of observation on 32 volunteers showed that mental activity that affected respiration can influence the function of autonomic nerve system in a different way. When the mind was concentrated at the inspiration, the function of autonomic nerve system was kept in balance, and both the sympathetic and the vagal activities enhanced significantly and while mind concentrated at the expiration could induce a reduction of vagal activity so as to produce marked change in the sympathovagal balance.

The CBP2 gene from Saccharomyces douglasii is a functional homologue of the Saccharomyces cerevisiae gene and is essential for respiratory growth in the presence of a wild-type (intron-containing) mitochondrial genome

In Saccharomyces cerevisiae the only known role of the CBP2 gene is the excision of the fifth intron of the mitochondrial cyt b gene (bI5). We have cloned the CBP2 gene from Saccharomyces douglasii (a close relative of S. cerevisiae). A comparison of the S. douglasii and S. cerevisiae sequences shows that there are 14% nucleotide substitutions in the coding region, with transitions being three times more frequent than transversions. At the protein level sequence identity is 87%. We have demonstrated that the S. douglasii CBP2 gene is essential for respiratory growth in the presence of a wild-type S. douglasii mitochondrial genome, but not in the presence of an intronless S. cerevisiae mitochondrial genome. Also the S. douglasii and S. cerevisiae CBP2 genes are completely interchangeable, even though the intron bI5 is absent from the S. douglasii mitochondrial genome.

Application of dot-immunogold-silver staining in the diagnosis of clonorchiasis

All 35 confirmed clonorchiasis cases showed a positive reaction in dot-immunogold-silver staining (Dot-IGSS) with a mean serum titre of 1:1656, while none of the sera from 35 normal individuals reacted. A seroepidemiological survey of middle-school students revealed a positive rate of 17.0% (142/836), and 76.1% (105/138) of the serologically positive students were egg positive in stool examination. The egg positive rates in those with antibody at levels of 1+ to 4+ were 57.1% (28/49), 75.7% (28/37), 94.7% (36/38) and 92.9% (13/14) respectively. It is believed that Dot-IGSS can be used for the clinical diagnosis and epidemiological survey of clonorchiasis.

[Chemical constituents of Rabdosia nervosa (Hemsl) C.Y. Wu et H. W. Li]

Three compounds were isolated from the stems and leaves of Rabdosa nervosa. On the basis of spectral analysis their structures were elucidated as lasiokaurin, ponicidin and oridonin respectively. These compounds were obtained from R. nervosa for the first time.

Simultaneous occurrence of fumonisin B1 and other mycotoxins in moldy corn collected from the People's Republic of China in regions with high incidences of esophageal cancer

A total of 31 corn samples collected from households in the counties of Cixian and Linxian of the People's Republic of China, where high incidences of esophageal cancer have been reported, were analyzed for fumonisin B1 (FB1), aflatoxin, and total trichothecene mycotoxins. High levels of FB1 (18 to 155 ppm; mean, 74 ppm) were found in 16 of the samples that showed heavy mold contamination. FB1, at lower levels (20 to 60 ppm; mean, 35.3 ppm), was also found in 15 samples, collected from the same households, that did not show any visible mold contamination. The levels of aflatoxin in the samples were low (1 to 38.4 ppb; mean, 8.61 ppb). High levels of total type-A trichothecenes were also found in the moldy corn samples (139 to 2,030 ppb; mean, 627 ppb). Immunochromatography of selected samples revealed that these samples contained T-2 toxin, HT-2 toxin, iso-neosolaniol, monoacetoxyscirpenol, and several other type-A trichothecenes. The concentration of total type-B trichothecenes in 15 moldy corn samples was in the range of 470 to 5,826 ppb (mean, 2,359 ppb). High levels (3.7 to 5.0 mg/g) of FB1 were produced in corn in the laboratory by five Fusarium moniliforme strains isolated from the moldy corn. These fungi were also capable of forming various nitrosamines (5 to 16 micrograms per flask) in the presence of nitrate and precursor amines.(ABSTRACT TRUNCATED AT 250 WORDS)

Nutrition intervention trials in Linxian, China: supplementation with specific vitamin/mineral combinations, cancer incidence, and disease-specific mortality in the general population

BACKGROUND

Epidemiologic evidence indicates that diets high in fruits and vegetables are associated with a reduced risk of several cancers, including cancers of the esophagus and stomach. Vitamins and minerals in these foods may contribute to the reduced cancer risk. The people of Linxian County, China, have one of the world's highest rates of esophageal/gastric cardia cancer and a persistently low intake of several micronutrients.

PURPOSE

We sought to determine if dietary supplementation with specific vitamins and minerals can lower mortality from or incidence of cancer as well as mortality from other diseases in Linxian.

METHODS

Individuals of ages 40-69 were recruited in 1985 from four Linxian communes. Mortality and cancer incidence during March 1986-May 1991 were ascertained for 29,584 adults who received daily vitamin and mineral supplementation throughout this period. The subjects were randomly assigned to intervention groups according to a one-half replicate of a 2(4) factorial experimental design. This design enabled testing for the effects of four combinations of nutrients: (A) retinol and zinc; (B) riboflavin and niacin; (C) vitamin C and molybdenum; and (D) beta carotene, vitamin E, and selenium. Doses ranged from one to two times U.S. Recommended Daily Allowances.

RESULTS

A total of 2127 deaths occurred among trial participants during the intervention period. Cancer was the leading cause of death, with 32% of all deaths due to esophageal or stomach cancer, followed by cerebrovascular disease (25%). Significantly (P = .03) lower total mortality (relative risk [RR] = 0.91; 95% confidence interval [CI] = 0.84-0.99) occurred among those receiving supplementation with beta carotene, vitamin E, and selenium. The reduction was mainly due to lower cancer rates (RR = 0.87; 95% CI = 0.75-1.00), especially stomach cancer (RR = 0.79; 95% CI = 0.64-0.99), with the reduced risk beginning to arise about 1-2 years after the start of supplementation with these vitamins and minerals. No significant effects on mortality rates from all causes were found for supplementation with retinol and zinc, riboflavin and niacin, or vitamin C and molybdenum. Patterns of cancer incidence, on the basis of 1298 cases, generally resembled those for cancer mortality.

CONCLUSIONS

The findings indicate that vitamin and mineral supplementation of the diet of Linxian adults, particularly with the combination of beta carotene, vitamin E, and selenium, may effect a reduction in cancer risk in this population.

IMPLICATIONS

The results on their own are not definitive, but the promising findings should stimulate further research to clarify the potential benefits of micronutrient supplements.

[Chemical constituents of Rosa laevigata Michx]

Six compounds were isolated from Rosa laevigata. Five of them were obtained from the ethanolic extract and identified as 2 alpha, 3 beta, 19 alpha, 23-tetrahydroxyurs-12-en-28-oic acid, 2 alpha, 3 alpha, 19 alpha, 23-tetrahydroxyurs-12-en-28-oic acid, euscaphic acid, beta-sitosterol and daucosterol. The other one was obtained from the acetate of emulsive layer of the petroleum ether and elucidared as 2 alpha, 3 beta-dihydrolup-28-methyl ester diacetate.

Cytologic screening for esophageal cancer: results from 12,877 subjects from a high-risk population in China

Linxian, China, has one of the highest esophageal-cancer mortality rates in the world. In 1983, esophageal balloon-cytology screening was performed to identify subjects eligible for 2 nutrition-intervention trials in Linxian; 12,877 subjects had cytology slides which were satisfactory for diagnosis. Of the 12,649 subjects with squamous-cell diagnoses, 31% were normal by Chinese cytologic criteria; 38% showed hyperplasia; 21% showed dysplasia 1; 6% showed dysplasia 2; 2% showed near-cancer; and 2% showed cancer. Of the 1,471 subjects with columnar-cell diagnoses, 31% were normal; 44% showed hyperplasia; 16% showed dysplasia 1; 4% showed dysplasia 2; 2% showed near-cancer; and 3% showed cancer. Squamous dysplasia and cancer were more common among females than males, while columnar dysplasia and cancer showed male predominance. The prevalence of dysplasia and cancer of both cell types increased with age. The prevalence of squamous dysplasia was significantly higher than in earlier balloon-cytology screenings in Linxian, probably reflecting changes in cytologic classification.