Cardiac MRI for clinical dilated cardiomyopathy: Improved diagnostic power via combined T1, T2, and ECV.

INTRODUCTION: Early diagnosis of patients with dilated cardiomyopathy (DCM) remains challenging. Cardiac MR can correlate myocardial changes with their pathological basis. There have been some previous studies on the effect of T1 mapping in DCM, but there is limited data on the incremental value of T2 mapping for DCM in routine clinical practice. This study will examine whether the combination of MRI T1 and T2 mapping offers greater advantages in the diagnosis of DCM. METHODS: The study included 28 patients with DCM and 21 healthy controls. CMR evaluation included late gadolinium enhancement (LGE), T1 mapping, extracellular volume (ECV) fraction and T2 mapping. The DCM group was divided into LGE (+) and LGE (-) subgroups. The main modes of LGE are subendocardial, midwall, subepicardial, or transmural. T1 values, T2 values, and ECV in the 16 segments myocardial levels were measured by post-processing software. Student's t-tests or Mann-Whitney U test was used to compare between two groups, and one-way ANOVA or Kruskal-Wallis H test was used to compare between multiple groups, with p values corrected by Bonferroni. The difference was considered statistically significant at P < 0.05. ROC curve analysis was used to compare the area under the curve (AUC) of each index and its combined value, and the cut-off value, sensitivity and specificity were determined by Jordan's index. RESULTS: Mean native myocardial T1, ECV and T2 were significantly higher in the DCM group compared to controls (p ≤ 0.001, respectively). The best cut-off values for T1, T2 and ECV to discriminate DCM from controls were 1184 ms, 40.9 ms and 29.2%, respectively. The AUC of T1, ECV and T2 were 0.87, 0.89, and 0.83, respectively. The combined AUC of the three values was 0.96. CONCLUSION: Native T1 value and ECV overcome some of the limitations of LGE, and the T2 helps to understand the extent of myocardial damage. The combination of T1 and T2 mapping techniques can reveal fibrotic and oedematous changes in the early stages of DCM, providing a more comprehensive assessment of DCM and better guidance for individualised clinical management of patients. IMPLICATIONS FOR PRACTICE: We suggest that the addition of T2 mapping to the routine CMR examination of patients with suspected DCM, and the combined assessment of T1mapping and T2 mapping can provide complementary information about the disease and improve the early diagnosis of DCM.

[Analysis on epidemiological characteristics of allergens with allergic skin diseases in a hospital in Beijing City from 2017 to 2021].

Objectives: In order to provide valuable information for the diagnosis and treatment of dermatitis, the prevalence rate and trend changes of common allergens in patients with allergic skin diseases in Beijing City were investigated and analyzed. Methods: This study was a retrospective data collection study. A total of 2 822 patients diagnosed with moderate to severe atopic dermatitis with allergen examinations were collected from Peking University First Hospital from 2017 to 2021, most of them were adults, and 83%(2 340/2 822) were over 18 years old. The ImmunoCAP fluorescent enzyme-linked immunoassay system was used to quantify specific IgE. The positive rate of each allergen was counted according to age, gender and year. The epidemiological characteristics and trends were analyzed. Results: In the past five years, 22 503 allergen-specific IgE test data were collected, and the positive rate of allergens in 40%(1 122/2 822) of the 2 822 patients was mainly multiple sensitization, the positive rate of allergens and multiple sensitization rates were the highest in people aged 13-18 years old. The 2 822 patients were dominated by inhaled allergens, and the highest positive rate was inhaled mixture (29.3%). The top five positive rates of inhaled allergens were Dermatophagoides farina (26.7%), Dermatophagoides pteronyssinus (25.5%), Mugwort (23.9%), Birch pollen (19.2%) and Siberian cocklebur (18.2%). The top five positive rates of food allergens were shrimp (15.2%), peanut (14.8%), sesame (14.7%), wheat (13.2%) and milk (13.1%). Analysis of the positive rate of allergens in different age groups showed except for the positive rate of birch pollen peaked at 3-12 years old, other inhaled allergens were the highest food allergens in 13-18 years old. Among food allergens, the positive rates of fx5, milk, egg and wheat were the highest in <3 years old, the positive rate decreased gradually with age, and the positive rate of other food allergens peaked at 13-18 years old, and the shrimp and crab was the highest in adult. The positive rate of various allergens in the 2 822 patients showed little difference between male and female and the male was slightly higher than female. In the past five years, the positive rate of allergens has been on the rise. The changes of inhaled allergens in cat/dog hair dander, Dermatophagoides farina and cicadas were large, while the positive rate of food allergens was stable. Conclusions: The etiology of the allergic skin diseases is complex, which may be related to allergen exposure, heredity, immunity, environmental factors, abnormal skin barrier function, etc. This study showed the distribution of allergens in patients with allergic skin diseases in Beijing City to a certain extent. It provided epidemiological data and clinical evidence for the prevention and treatment of allergic diseases.

[Incidence and cause of abnormal cholesterol in children aged 2-18 years in a single center].

OBJECTIVE: To investigate the abnormality and distribution of plasma cholesterol levels in single-center hospitalized children. METHODS: The blood lipid levels of children aged 2-18 years who had blood lipid test results in Peking University First Hospital from June 2016 to June 2019 were etrospectively analyzed. Cholesterol oxidase method was used for total cholesterol, and high-density lipoprotein cholesterol and low-density lipoprotein cholesterol were detected by clearance method. The counting data were compared with chi-square test. RESULTS: The survey had involved 11 829 children (7 087 were boys and 4 742 were girls). 1 822 (15.4%) children were with elevated total cholesterol, 1 371 (11.6%) children with elevated low-density lipoprotein cholesterol, and 2 798 (23.7%) children with high-density lipoprotein cholesterol reduction. The total number of the children with abnormal cholesterol levels was 4 427 (37.4%). Among the 7 835 children who visited hospital due to the disease not commonly inducing dyslipidemia, 731 (9.3%) had elevated TC, 561 (7.2%) had elevated LDL-C, 1 886 (24.1%) had decreased HDL-C, and 2 576 (32.9%) had abnormal cholesterol levels. Among the children with different diseases, the difference in the incidence of abnormal cholesterol was statistically significant. The top three main groups of the children with increased total cholesterol and low-density lipoprotein cholesterol were "dyslipidemia", "urinary tract disease", and "nutritional disease"; The top three main groups of the children with reduced high-density lipoprotein cholesterol were "respiratory diseases", "dyslipidemia", "hematological diseases and malignant tumors". Among the 1 257 blood li-pid test results sent by other departments, 300 cases had abnormal cholesterol levels (23.8%). Among them, there were 70 children with hypercholesterolemia (5.6%), 44 children with increased low-density lipoprotein cholesterol (3.5%), and 224 children with reduced high-density lipoprotein cholesterol (17.8%). There were 365 (4.6%) children with low-density lipoprotein cholesterol ≥140 mg/dL (3.6 mmol/L) who needed to further exclude familiar hypercholesterolemia among the children who visited hospitals due to the disease not commonly inducing dyslipidemia. CONCLUSION: Children in hospitals have a high incidence of cholesterol abnormalities. Doctors need to pay more attention to the cholesterol diagnosis and management regardless of the discipline, which not only helps to control secondary hypercholesterolemia, but also provides the possibility of detecting familial hypercholesterolemia in time.

[Clinical value of serum isoform [-2] proprostate-specific antigen and its derivatives in predicting aggressive prostate cancer].

OBJECTIVE: To explore the clinical value of serum isoform [-2] proprostate-specific antigen (p2PSA) and its derivatives %p2PSA and prostate health index (PHI) in predicting aggressive prostate cancer (PCa). METHODS: The pre-operation serum and basic clinical data of 322 patients with PCa (including 143 patients diagnosed with PCa by transrectal ultrasound-guided prostate biopsy and 179 patients undergoing radical prostatectomy) in Peking University First Hospital were collected from August 2015 to May 2018. Serum total prostate-specific antigen (tPSA), free prostate antigen (fPSA) and fPSA/tPSA (f/t) and the p2PSA level of all these patients were measured on automatic immune analyzers DxI800, and then %p2PSA and PHI were calculated. The prostate pathologic result was considered as the gold standard to evaluate the Gleason score of the patients with PCa. Receiver operator curves (ROC) were used to assess the ability of p2PSA, %p2PSA and PHI to predict aggressive PCa (pathologic Gleason score≥7) compared with those traditional markers tPSA, fPSA and f/t. RESULTS: Among these patients, the p2PSA, %p2PSA and PHI median levels were significantly higher in patients with pathologic Gleason score≥7 than those with Gleason score<7 (p2PSA: 30.22 ng/L vs. 18.33 ng/L; %p2PSA: 2.50 vs. 1.27; PHI: 91.81 vs. 35.44; all P<0.01). The area under curve (AUC) of %p2PSA and PHI (0.770, 0.760) in predicting Gleason score≥7 were higher than those of the traditional indicators tPSA, fPSA and f/t (AUC were 0.648, 0.536 and 0.693, respectively). Among those patients diagnosed with PCa by transrectal ultrasound-guided prostate biopsy, the AUC of %p2PSA and PHI (AUC were 0.808 and 0.801, respectively) in predicting Gleason score≥7 were higher than those of the traditional indicators tPSA, fPSA and f/t (AUC were 0.729, 0.655 and 0.665 respectively). Among those patients undergoing radical prostatectomy, PHI and %p2PSA also had the trend of higher predictive value than those of the traditional indicators. The AUC of %p2PSA and PHI were 0.798 and 0.744, respectively while the AUC of tPSA, fPSA and f/t were 0.625, 0.507 and 0.697, respectively. CONCLUSION: Compared with traditional markers tPSA, fPSA and f/t, %p2PSA and PHI had much higher predictive value for aggressive PCa, which may help clinicians to evaluate the therapeutic regime and make more appropriate management plan for the patients.

[Expression of Tim-3 on natural killer cells in patients with acute myeloid leukemia and its clinical significance].

Objective: To investigate the expression characteristics of Tim-3 on natural killer (NK) cells of peripheral blood in patients with acute myeloid leukemia (AML) and its clinical significance. Methods: Peripheral blood was obtained from 39 patients with newly diagnosed AML before intervention, with peripheral blood from 28 cases of healthy volunteers collected as normal control. Using CD3, CD56 and Tim-3 as markers, expression levels of Tim-3 on the peripheral blood NK cells were detected by immune fluorescence labeling and flow cytometry. Results: The ratio of the peripheral blood CD3(-)CD56(+) NK cells in newly diagnosed AML patients (5.74±5.31) %decreased significantly, compared with the normal control (12.55±6.33) % (t=4.596, P<0.001) . Tim-3 expression on the peripheral blood NK cells in newly diagnosed AML patients (42.67±19.08) % decreased significantly, compared with the normal control group (60.99±20.69) % (t=3.781, P<0.001) . CD3(-)CD56(+)NK cell ratio of peripheral blood in AML patients was significantly correlated with Chromosome karyotype (t=2.915, P<0.005) . Expression level of Tim-3 on NK cells in the peripheral blood of AML patients had significant correlation with ratio of CR and NCCN high risk group (P<0.05) . Conclusion: The rate of NK cells in peripheral blood and the expression level of Tim-3 on NK cells in AML patients decreased significantly.The lower expression level of Tim-3 on NK cells correlate with prognosis of AML.

Effect of Dietary sugar beet pulp supplementation on growth performance, nutrient digestibility, fecal Microflora, blood profiles and Diarrhea incidence in weaning pigs.

BACKGROUND: In 2006, the European Union (EU) has decided to forbid use of antibiotics as growth promoters. Although many researches had been conducted about fiber source as alternatives of antibiotics, there are still lack of reports in the literature about the optimum level of sugar beet pulp supplementation, affecting growth performance and nutrient digestibility in weaning pigs. Therefore, different level of sugar beet pulp was added to diets to determine the effects of sugar beet pulp supplementation on growth performance, nutrient digestibility, fecal microflora, blood profile and incidence of diarrhea in weaning pigs. METHODS: A total of 200 weaning pigs [(Yorkshire × Landrace) × Duroc], averaging 9.01 ± 1.389 kg of initial body weight were, allotted to 5 treatments in a randomized complete block (RCB) design. Each treatment was composed of 4 replicates with 10 pigs per pen. The treatments were control treatment: Corn-SBM basal diet + ZnO (phase 1: 0.05%; phase 2; 0.03%) and four different levels of sugar beet pulp were supplemented in Corn-SBM basal diet (3, 6, 9 or 12%). Two phase feeding programs (phase 1: 1-2 weeks; phase 2: 3-5 weeks) were used for 5 week of growth trial. RESULTS: In feeding trial, there were no significant differences in growth performance and incidence of diarrhea among treatments. The E.coli counts were not significantly different among dietary treatments but linear response was observed in Lactobacillus counts as sugar beet pulp supplementation increased (P < 0.05). In addition, IGF-1, IgA and IgG were not affected by dietary treatments. However, the BUN concentration was decreased when pigs were fed the treatments of diets with SBP compared to that of control treatment (P < 0.05). In nutrient digestibility, crude fiber and NDF digestibilities were improved as the sugar beet pulp increased (P < 0.05). However, digestibilities of crude ash, crude fat, crude fiber and nitrogen retention were not affected by dietary sugar beet pulp levels. CONCLUSION: This experiment demonstrated that sugar beet pulp can be supplemented in weaning pigs' diet instead of ZnO to prevent postweaning diarrhea without any detrimental effect on growth performance.

Effect of vitrification on the mRNA transcriptome of bovine oocytes.

Vitrification has been shown to decrease the developmental capacity of mammalian oocytes, and this is closely associated with the abnormal mRNA expressions of vitrified oocytes. However, the effect of vitrification on transcriptional machinery of oocytes examined by RNA sequencing (RNA-seq) has yet to be defined. In the present study, the mRNA transcriptomes of fresh and vitrified bovine oocytes were analysed by Smart-seq2 with the differently expressed genes determined by DEseq2 (an adjusted p-value of .05 and a minimum fold change of 2). The differentially expressed mRNAs were then searched against the Gene Ontology (GO) and Genomes (KEGG) database. Finally, the mRNA expressions of 10 candidate genes were validated using quantitative real-time PCR (qRT-PCR). Approximately 12,000 genes were detected in each sample of fresh or vitrified oocytes. Of these, the expression levels of 102 genes differed significantly in vitrified groups: 12 genes mainly involved in cell cycle, fertilization and glucose metabolism were upregulated, and 90 genes mainly involved in mitochondria, ribosomal protein, cytoskeleton, transmembrane protein, cell cycle and calcium ions were downregulated. GO analysis showed that these genes were mainly enriched in terms of membrane-bounded organelles, macromolecular complex, and intracellular part. The mRNA expression levels of 10 candidate genes selected randomly were in agreement with the results of the RNA-seq. In conclusion, our results showed that vitrification affected the mRNA transcriptome of bovine oocytes by downregulating genes, which contributed to the decreased developmental capacity of vitrified oocytes. Our findings will be useful in determining approaches to improve the efficiency of vitrified oocytes.

Determinants of suicidal ideation in gynecological cancer patients.

OBJECTIVE: Gynecological cancer survivors are at increased risk of psychological problems including suicide risk. Suicidal ideation, which was thought to be precursor to suicide attempts, has not been well studied. This study aimed to investigate the prevalence, and determinants of suicidal ideation for women with gynecological cancer, and then to assess the effect of coping style and social support on suicidal ideation. METHODS: Patients with cervical, ovarian and endometrial cancers seen at Hunan Provincial Tumor Hospital from September 2012 to June 2013 were consecutively recruited and were asked to complete the Zung Self-Rating Depression Scale, Suicidal Ideation of Self-rating Scale, Medical Coping Modes Questionnaire and Social Support Rating Scale. Path analysis was used to examine the relationship among coping style, social support, depression symptoms and suicidal ideation. RESULTS: A total of 579 (579/623, 93.0%) gynecological cancer patients were enrolled in this study and completed all investigations between September 2012 and June 2013. Among them, 105 (18.1%) patients reported suicidal ideation, with the highest rate in patients with ovarian cancer (30.16%). Suicidal ideation was associated with depression symptoms, care providers, chemotherapy history and acceptance-resignation. Path analysis showed that the acceptance-resignation affected suicidal ideation directly as well as mediated by social support and depression symptoms, while confrontation and avoidance affected suicidal ideation entirely through social support and depression symptoms. CONCLUSIONS: Suicidal ideation is high among patients with gynecological cancer, especially among ovarian cancer patients. Coping strategies such as confrontation and avoidance, and social support may be helpful for preventing suicidal ideation among them.

Analytical performance of the Abbott Architect i2000 tacrolimus assay in Chinese patients after renal transplantation.

BACKGROUND: Monitoring of tacrolimus concentrations has played a crucial role to control the efficacy versus adverse effects of treatment, because of the drug's narrow therapeutic range, inter- and intraindividual variabilities, and drug interactions mediated by hepatic cytochrome P450. Therefore, the stability of methods to monitor tacrolimus is of major importance. This study evaluated the analytical performance of the Abbott Architect i2000 tacrolimus assay, which was recently released in China to monitor tacrolimus therapy. We compared the results using the Abbott Architect i2000 Tacrolimus assay with the traditional Abbott IMx method. METHODS: We measured concentrations of tacrolimus in 100 samples from renal transplant patients by Architect i2000 and the commonly used Abbott IMx. RESULTS: We observed that the total %CV of the Architect i2000 assay was <10%, both at low and high concentration levels, with a functional sensitivity of <0.5 ng/mL. The Architect i2000 assay was linear over the reportable range with recoveries ranging from 90.6% to 106.7%. In addition, this assay was not affected by high concentrations of hemoglobin, lipids, or bilirubin in the samples. The 2 assays yielded similar results. The regression equation obtained from the Passing Bablok analysis was: y = 0.8788x - 0.3485 with a Spearman correlation coefficient (r) of 0.9922. The bias plot between the Architect i2000 and Abbott IMx assay yielded an average negative bias (-1.4 ng/mL). CONCLUSION: We concluded that, because of its high precision and sensitivity, low cross-reactivity, and acceptable accuracy, the Architect i2000 assay is a suitable alternative to monitor tacrolimus concentrations in renal transplant recipients.

Analysis of community structure of a microbial consortium capable of degrading benzo(a)pyrene by DGGE.

A microbial consortium was obtained by enrichment culture of sea water samples collected from Botan oil port in Xiamen, China, using the persistent high concentration of a mixture of polycyclic aromatic hydrocarbons enrichment strategy. Denaturing gradient gel electrophoresis (DGGE) was used to investigate the bacterial composition and community dynamic changes based on PCR amplification of 16S rRNA genes during batch culture enrichment. Using the spray-plate method, three bacteria, designated as BL01, BL02 and BL03, which corresponded to the dominant bands in the DGGE profiles, were isolated from the consortium. Sequence analysis showed that BL01, BL02 and BL03 were phylogenetically close to Ochrobactrum sp., Stenotrophomonas maltophilia and Pseudomonas fluorescens, respectively. The degradation of benzo(a)pyrene (BaP), a model high-molecular-weight polycyclic aromatic hydrocarbon (HMW PAH) compound was investigated using individual isolates, a mixture of the three isolates, and the microbial consortium (BL) originally isolated from the oil port sea water. Results showed that the order of degradative ability was BL>the mixture of the three isolates>individual isolates. BL degraded 44.07% of the 10 ppm BaP after 14 days incubation, which showed the highest capability for HMW PAH compound degradation.Our results revealed that this high selective pressure strategy was feasible and effective in enriching the HMW PAH-degraders from the original sea water samples.

PAHs contamination and bacterial communities in mangrove surface sediments of the Jiulong River Estuary, China.

Sixteen sediment samples collected from eight transects in a mangrove swamp of the Jiulong River Estuary, Fujian, China were investigated for their content of polycyclic aromatic hydrocarbons (PAHs) and the biodegradation potential of the indigenous microorganisms. The bacterial community structures in the mangrove sediments and in enrichment cultures were also investigated. The results showed that the total PAHs concentration of mangrove sediments ranged from 280 to 1074 ng g(-1) dry weight, that the PAHs composition pattern in the mangrove sediments was dominated by high molecular weight PAH components (4-6 rings), and that Benzo[ghi]perylene and Indeno[1,2,3-cd]pyrene were the most dominant at different stations. Abundant PAH-degrading bacteria were found in all the stations, the values of phenanthrene-degrading bacteria ranged from 5.85 x 10(4) to 7.80 x 10(5) CFU g(-1) dry weight, fluoranthene-degrading bacteria ranged from 5.25 x 10(4) to 5.79 x 10(5) CFU g(-1) dry weight, pyrene-degrading bacteria ranged from 3.10 x 10(4) to 6.97 x 10(5) CFU g(-1) dry weight and the benzo(a)pyrene-degrading bacteria ranged from 5.25 x 10(4) to 7.26 x 10(5) CFU g(-1) dry weight. DGGE analysis of PCR-amplified 16S rDNA gene fragments confirmed that there was a remarkable shift in the composition of the bacterial community due to the addition of the different model PAH compound phenanthrene (three ring PAH), fluoranthene(four ring PAH), pyrene(four ring PAH) and benzo(a)pyrene(five ring PAH) during enrichment batch culture. Eleven strains were obtained with different morphology and different degradation ability. The presence of common bands for microbial species in the cultures and in the native mangrove sediment DNA indicated that these strains could be potential in situ PAH-degraders.

Vitrification of boer goat morulae and early blastocysts by straw and open-pulled straw method.

The aim of this study was to investigate the effects of different vitrification solutions [EFS30 or EFS40 contains 30% (v/v) ethylene glycol (EG), 40% (v/v) EG; EDFS30 or EDFS40 contains 15% (v/v) EG and 15% (v/v) dimethyl sulfoxide (DMSO), 20% (v/v) EG and 20% (v/v) DMSO], equilibrium time during vitrification (0.5-2.5 min) and vitrification protocols [one-step straw, two-step straw and open-pulled straw (OPS)] on in vivo development of vitrified Boer goat morulae and blastocysts after embryo transfer. In the one-step straw method, the lambing rates of vitrified embryos in EFS30 (37.5%), EFS40 (40.5%) or EDFS30 (38.2%) group were similar to that of fresh embryos (57.5%) and conventional freezing method (46.7%) when the equilibrium time was 2 min. In the two-step straw method, the highest lambing rate was obtained when embryos were pretreated with 10% EG for 5 min and then exposed to EFS40 for 2 min (51.4%), showing similar lambing rates compared with fresh embryos (56.1%) or the embryos cryopreserved by conventional freezing method (45.2%). In the OPS method, the lambing rate in EFS40, EDFS30 or EDFS40 groups were similar to that (57.1%) of fresh embryos, or to that (46.0%) of embryos cryopreserved by conventional freezing method. The highest lambing rate (51.4%) of the group of OPS was obtained when the embryos were vitrified with EDFS30. In conclusion, either the two-step straw method in which embryos were pretreated in 10% EG for 5 min and then exposed to EFS40 for 2 min, or the OPS method in which embryos were pretreated in 10% EG + 10% DMSO for 30 s and then exposed to EDFS30 for 25 s was a simple and efficient method for the vitrification of Boer goat morulae and blastocysts.

Treatment of toxic epidermal necrolysis with intravenous immunoglobulin.

Toxic epidermal necrolysis (TEN) is a rare severe reaction of the skin resulting in full thickness damage to the epidermis. The condition has significant morbidity as a result of dehydration, protein loss, thermoregulatory difficulties, and renal, lung, liver and heart failure. The mortality rate approaches 30%, most commonly from bacterial sepsis. Management of this condition is cessation of the suspected causative agent and supportive care on a burns or intensive care unit. There have been recent reports of treatment using intravenous immunoglobulin (IVIG) therapy, though its efficacy is yet to be established. It has been proposed that IVIG inhibits the Fas-FasL mediated apoptosis of keratinocytes affected by TEN. We describe a case of extensive drug-induced TEN in a 33-year-old woman who showed rapid improvement with IVIG therapy at a dose of 0.75 g/kg/day given for four consecutive days.

Discovery of a regulatory motif that controls the exposure of specific upstream cyclin-dependent kinase sites that determine both conformation and growth suppressing activity of pRb.

The conformation and activity of pRb, the product of the retinoblastoma susceptibility gene, is dependent on the phosphorylation status of one or more of its 16 potential cyclin-dependent kinase (cdk) sites. However, it is not clear whether the phosphorylation status of one or more of these sites contributes to the determination of the various conformations and activity of pRb. Moreover, whether and how the conformation of pRb may regulate the phosphorylation of the cdk sites is also unclear. In the process of analyzing the function and regulation of pRb, we uncovered the existence of an unusual structural motif, m89 (amino acids 880-900), the mutation of which confers upon pRb a hypophosphorylated conformation. Mutation of this structural domain activates, rather than inactivates, the growth suppressor function of pRb. In order to understand the effect of the mutation of m89 on the phosphorylation of cdk sites, we identified all the cdk sites (Thr-356, Ser-807/Ser-811, and Thr821) the phosphorylation of which drastically modify the conformation of pRb. Mutation of each of these four sites alone or in combinations results in the different conformations of pRb, the migration pattern of which, on SDS-polyacrylamide gel electrophoresis, resembles various in vivo hypophosphorylated forms. Each of these hypophosphorylated forms of pRb has enhanced growth suppressing activity relative to the wild type. Our data revealed that the m89 structural motif controls the exposure of the cdk sites Ser-807/Ser-811 in vitro and in vivo. Moreover, the m89 mutant has enhanced growth suppressing activity, similar to a mutant with alanine substitutions at Ser-807/Ser-811. Our recent finding, that the m89 region is part of a structural domain, p5, conserved antigenically and functionally between pRb and p53, suggests that the evolutionarily conserved p5 domain may play a role in the coordinated regulation of the activity of these two tumor suppressors, under certain growth conditions.

[Study on anti-histone fraction antibodies in patients with rheumatic diseases].

By using Western blot method, we studied the antihistone fraction antibodies in sera of patients with rheumatic diseases. After analysed with SDS-PAGE, the histone could be separated into H1, H3, H2B, H2A and H4 fractions. The positive rate of anti-histone fraction antibodies was highest (82.1%) in systemic lupus erythematosus (SLE) patients, especially in active stage. In 28 SLE patients, the positive rates of anti-H2B, -H1, -H3, -H2A and -H4 were 78.6%, 60.7%, 50.0%, 35.7% and 7.1% respectively. The results revealed that the determination of anti-histone fraction antibodies was beneficial to the diagnosis of SLE.

Autologous immune complex glomerulonephritis induces abnormal embryonic development.

Young female random-bred Wistar rats were immunized with homologous renal brush border membranes. The immunized animals exhibited all the clinical and immunopathological characteristics of chronic autologous immune complex glomerulonephritis (Heymann nephritis) closely resembling the idiopathic membranous glomerulonephritis in humans. The animals were subsequently mated. Congenital malformations and fetal growth retardation were observed in the offspring of the nephritic mothers; high incidence of embryonic/fetal resorptions was also observed. The types of anomalies were microphthalmia, cataractic lens, abnormal retina, micrognathia, cleft palate, lordosis, fetal edema, variable hemorrhage, omphalocele, syndactaly and cryptochidism. The most frequently observed anomaly was associated with the eye. Immunofluorescent studies indicated that no rat IgG was detected in the extraembryonic membranes, embryo or fetuses. Rat complement C3 was also absent around the conceptuses. The pathophysiologic mechanism leading to such deleterious embryonic/fetal effect is not clear.

Teratogenic antibodies are directed against a coated-pit glycoprotein.

It has been well established that heterologous antibodies against certain tissue components may cause congenital abnormalities when injected into pregnant rats during the critical period of organogenesis. A glycoprotein antigen (gp340) of rat renal proximal tubules was isolated (C.C.K. Leung: (J. Exp. Med., 156:372-384, 1982); antibodies against gp340 were teratogenic. Indirect colloidal gold immunocytochemical method was utilized to study the ultrastructural localization of gp340. For comparative studies, both preembedding and postembedding immunostaining procedures were used. The results indicate that gp340 is a resident of coated pits and possibly also of coated vesicles of the rat renal proximal tubules and visceral yolk-sac (VYS) endodermal cells. It appears that gp340 may also be associated with the microvilli and some as-yet-unidentified cytoplasmic structures of the same tissues. However, gp340 is absent on the epithelium of the small intestine. It is hypothesized that the teratogenic antibodies may interact with gp340 on the coated pits and interfere with receptor-mediated endocytosis, causing yolk-sac placenta dysfunction which in turn causes abnormal embryonic development.

Teratogenic antibody internalization by rat visceral yolk-sac endoderm in vitro: an ultrastructural colloidal gold tracer study.

Previous work from our laboratory has demonstrated that specific rabbit immunoglobulins G (IgG) against a glycoprotein antigen of rat kidney proximal tubule or a cross-reacting visceral yolk-sac endodermal cell antigen will induce abnormal embryonic development when they are injected into pregnant rats during the period of organogenesis. It has been proposed that these antibodies may induce embryopathy by interfering with functions of the visceral yolk-sac placenta, an important organ providing nutrients to the embryo at this stage of development. In order to gain some insight into the underlying pathogenic mechanism(s) in which specific teratogenic IgG may interfere with visceral yolk-sac functions, we examined the uptake of these teratogenic IgG by the visceral yolk-sac endodermal cells at the electron microscopic level. The results demonstrated that teratogenic rabbit IgG specifically localized on the fuzzy coat of the external apical cell membrane of the visceral yolk-sac endoderm at the intermicrovillous region. Within 5 min, the IgG were rapidly internalized via coated pits and micropinocytic vesicles. Within 30 min, an increasing proportion of gold particles appeared within uncoated vesicles or vacuoles of various sizes; most of the gold particles were in close proximity to the inner membranous lining of the vesicles. Similar findings were observed after 1- or 2-hr incubation. After 24- to 48-hr culture, however, the gold particles appeared to have dissociated from the inner surface of the vesicle membrane.(ABSTRACT TRUNCATED AT 250 WORDS)