[A cohort study on the association between resting heart rate and the risk of new-onset heart failure]

Objective: To prospectively explore the relationship between resting heart rate (RHR) and risk of new-onset heart failure. Methods: It was a prospective cohort study. People who attended the physical examination of Kailuan Group Company in 2006 and with complete electrocardiography (ECG) recordings were eligible for this study. A total of 88 879 participants aged 18 years old or more who were free of arrhythmia, a prior history of heart failure and were not treated with β-blocker were included. Participants were divided into 5 groups according to the quintiles of RHR at baseline (Q(1) group, 40-60 beats/minutes (n=18 168) ; Q(2) group, 67-70 beats/minutes (n=18 970) ; Q(3) group, 71-74 beats/minutes (n=13 583) ; Q(4) group, 75-80 beats/minutes (n=22 739) ; and Q(5) group,>80 beats/minutes (n=15 419) ) .The general clinical data and laboratory test results were collected. The outcome was the first occurrence of heart failure at the end of follow-up (December 31, 2016) .We used Cox regression model to examine the association between RHR and the risk of new-onset heart failure. Hazard ratio (HR) with 95% confidence intervals (CI) were calculated using Cox regression modeling. Results: Among the included patients 68 411 participants were male, mean age was (51.0±12.3) years old, and RHR was (74±10) beats/minutes. Statistically significant differences among the RHR quintiles were found for the following variables: age, gender, systolic blood pressure, diastolic blood pressure, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting blood glucose, body mass index, the level of high-sensitivity C-reactive protein, education status, physical activity, smoking status, drinking status, history of diabetes, history of hypertension and history of use antihypertensive drugs (all P<0.01) . Higher RHR was linked with higher prevalence of diabetes, hypertension history, and higher systolic blood pressure, diastolic blood pressure and FBG levels (all P<0.01). After a mean follow-up of 9.5 years, the incidence of new-onset heart failure in Q(1), Q(2), Q(3), Q(4) and Q(5) groups was 1.60%(290/18 168), 1.36%(258/18 970), 1.80%(245/13 583), 1.76%(400/22 739) and 2.35%(362/15 419),respectively (P<0.01) . The person-year incidence of heart failure in Q(1), Q(2), Q(3), Q(4) and Q(5) groups was 1.7, 1.5, 1.9, 1.9 and 2.6 per 1 000 person-years respectively. Compared with the Q(2) group, multivariate analysis with adjustment for major traditional cardiovascular risk factors showed that HRs of Q(3),Q(4),and Q(5) group were 1.23 (95%CI 1.03-1.48, P<0.05) , 1.19 (95%CI 1.01-1.41, P<0.05) , 1.39 (95%CI 1.18-1.65, P<0.01) , respectively. In the absence of hypertension, diabetes, smoking and acute myocardial infarction, the Cox regression model showed that compared with Q(2) group, the HR of new-onset heart failure in Q(5) group was 1.58 (95%CI 1.02-2.45, P<0.05) . Conclusion: Increased RHR is associated with increased risk of new-onset heart failure in this cohort.

Expression and prognostic significance of melatonin receptor MT1 in patients with gastric adenocarcinoma

Melatonin receptor type 1 (MTNR1A or MT1) is known to play an important role in cancer progression; however, its prognostic value for resected gastric adenocarcinoma (RGA) is unknown. In this study, we examined the potential of MT1 as a prognostic biomarker for RGA. The expression of the MT1 was evaluated in 67 patients with RGA by immunohistochemistry, and the relationship between MT1 levels and RGA prognosis was analyzed by Chi-square test, multivariate Cox regression, Kaplan-Meier method, and log-rank test. High MT1 expression was associated with a poor survival rate (29.0%, p=0.002) and the occurrence of metastasis (62.9%, p=0.004). Kaplan-Meier survival analysis and log rank tests revealed that patients with high expression of the MT1 had significantly shorter median overall survival compared to those with low expression (33.0 vs. 65.0 months, respectively; p=0.02). Multivariate Cox analysis indicated that the calculated death risk (hazard ratio [HR]) in patients with high expression levels of the MT1 increased to 2.68 (95% confidence interval [CI] 1.21-5.94, p=0.015), which was higher compared to those with low levels. HR of death was also high in patients with advanced T stage (2.51; 95 % CI 1.00-6.26, p=0.049) and metastasis (5.02; 95% CI 1.94-13.03, p=0.001). Our results showed that high MT1 expression in primary gastric adenocarcinoma tissues was associated with the occurrence of metastasis and poor prognosis. It may have prognostic significance as a potential biomarker in patients with RGA.

Genome-wide analyses reveal the role of noncoding variation in complex traits during rice domestication

Genomes carry millions of noncoding variants, and identifying the tiny fraction with functional consequences is a major challenge for genomics. We assessed the role of selection on long noncoding RNAs (lncRNAs) for domestication-related changes in rice grains. Among 3363 lncRNA transcripts identified in early developing panicles, 95% of those with differential expression (329 lncRNAs) between Oryza sativa ssp. japonica and wild rice were significantly down-regulated in the domestication event. Joint genome and transcriptome analyses reveal that directional selection on lncRNAs altered the expression of energy metabolism genes during domestication. Transgenic experiments and population analyses with three focal lncRNAs illustrate that selection on these loci led to increased starch content and grain weight. Together, our findings indicate that genome-wide selection for lncRNA down-regulation was an important mechanism for the emergence of rice domestication traits.

[The multicenter study on the registration and follow-up of low anticoagulation therapy for the heart valve operation in China]

OBJECTIVE

To investigate the optimal anticoagulation methods and monitoring strategy for Chinese patients undergoing heart valve replacement, which is potentially quite different from western populations.

METHODS

In this multicenter prospective cohort study, the anticoagulation and monitoring strategy data was acquired from 25 773 in-hospital patients in 35 medical centers and 20 519 patients in outpatient clinic in 11 medical centers from January 1st, 2011 to December 31th, 2015.

RESULTS

As for in-hospital patients, mean age of study population was (48.6±11.2) years old; main etiology of valve pathology was rheumatic (87.5%) origin among study cohort; 94.8% of study population received mechanical valve implantation; international normalized ratio (INR) monitoring (in all the study centers) and low-intensity anticoagulation strategy (31 hospitals chose target INR range of 1.5-2.5, and actual values of INR among 89.2% of 100 069 in-hospital monitoring samples were 1.5-2.5), with mean actual INR values of 1.84±0.53, and warfarin dosage of (2.82±0.93) mg/d were widely adopted among the study centers; strategies of in-hospital warfarin administration were similar in all the study centers; complication rates of low-intensity anticoagulation strategy were low in severe hemorrhage (0.02%), thrombosis (0.05%), and thromboembolism (0.05%) events, without anticoagulation-related death.As for 18 974 outpatient clinic patients, the follow-up rate was 92.47%, with a total of 30 012 patient-years (Pty). Anticoagulation-related morbidity and mortality rates were 0.67% and 0.15% Pty; major hemorrhage morbidity and mortality rates were 0.25% and 0.13% Pty; thromboembolism morbidity and mortality rates were 0.45% and 0.03% Pty.The mean dosage of warfarin daily dosage was (2.85±1.23) mg/d and INR value was 1.82±0.57.No significant regional difference in the intensity of anticoagulation therapy was noted during the study.

CONCLUSIONS

INR can be used as a normalized indicator for intensity of anticoagulation therapy in China.The optimal anticoagulation intensity with INR range from 1.5 to 2.5 is safe and effective for Chinese patients with heart valve replacement, and there is no significant regional difference in the intensity of anticoagulation therapy.

[Association between the office, visit-to-visit and 24-hour ambulatory systolic blood pressure and vascular damages in the elderly]

OBJECTIVE

To investigate the association between different kinds of systolic blood pressure (SBP, including office, visit-to-visit, 24-hour ambulatory) and vascular damages (represented by carotid intima-media thickness, CIMT; brachial-ankle pulse wave velocity, baPWV) in the elderly.

METHODS

A total of 2 814 participants aged of ≥60 years old and retired employees were selected with random sampling method from the individuals who took part in 2006-2007, 2008-2009, 2010-2011 health examination in Tangshan Kailuan Hospital, Kailuan Linxi Hospital, Kailuan Zhaogezhuang Hospital and with 24-hour ambulatory blood pressure monitoring data, CIMT and baPWV.Finally, 2 146 participants (1 438 males, average age (67.3±6.0) years old) were included to the analysis.Multivariable regression analysis was used to analyze association between the office, visit-to-visit, 24-hour, day-time, night-time SBP and CIMT and baPWV, respectively.

RESULTS

(1) The average SBP, DBP, CIMT and baPWV were (137.0±20.4) mmHg(1 mmHg=0.133 kPa), (83.5±11.0) mmHg, (0.92±0.18)mm and (1 781.7±353.2)cm/s.(2) The participants were divided into high and low level groups according to the median of different SBPs, respectively.The results indicated that CIMT and baPWV were significantly higher in high level groups than in low level groups (all P<0.01). (3) After adjusting for gender and age, the partial correlate analysis showed that the office, visit-to-visit, 24-hour, day-time, night-time SBP positively associated with CIMT and baPWV (all P<0.01). (4) After adjusting for confounding factors, multivariable regression analysis showed that the office, visit-to-visit, 24-hour, day-time, night-time SBP were positively and linearly associated with CIMT and baPWV in total cohort, and standard regression coefficients were 0.157, 0.208, 0.175, 0.169, 0.163, 0.479, 0.420, 0.401, 0.389 and 0.354, respectively.In addition, similar results were observed in male and female participants but there was no significance between night-time SBP and CIMT in female participants.

CONCLUSIONS

Office, visit-to-visit, 24-hour, day-time, night-time SBP are associated with vascular damages, and the best associations are observed between visit-to-visit SBP and vascular function damage.

CLINICAL TRIAL REGISTRY

Chinese CLINICAL TRIAL REGISTRY, ChiCTR-TNC-1100 1489.

[Influencing factors of orthostatism brachial-ankle pulse wave velocity and ankle brachial index in the elderly]

OBJECTIVE

To investigate the distribution and influencing factors of orthostatism brachial-ankle pulse wave velocity(baPWV) and ankle brachial index(ABI) in the elderly.

METHODS

Participants were selected with random sampling from ≥60 years old retired workers, who underwent 2010 to 2011 health check-up in the Tangshan Kailuan Hospital, Kailuan Linxi Hospital, Kailuan Zhaogezhuang Hospital. Multivariate linear regression analysis was used to analyze the influencing factors of orthostatism and supine baPWV and ABI in the elderly.

RESULTS

(1) A total of 2 464 participants were included, and 1 601 participants (1 065 males(66.5%) and (67.5±6.1) years old) with integral data were analyzed. Orthostatism baPWV was (3 885.4±1 503.5)cm/s and Supine baPWV was (1 761.2±371.4)cm/s.Orthostatism ABI was 1.54±0.21 and supine ABI was 1.10±0.12. Orthostatism baPWV increased with increasing age, while orthostatism ABI decreased with aging(trend test, both P<0.01)in <65, 65-69, 70-74, and ≥75 years old participants.(2) Multiple linear regression analysis showed that the age(β=0.19, P<0.01), lower limbs orthostatism systolic blood pressure(β=0.18, P<0.01), lower limbs supine systolic blood pressure (β=0.14, P<0.01), orthostatism heart rate (β=0.30, P<0.01), supine heart rate (β=0.23, P<0.01), body mass index (β=-0.18, P<0.01) were associated with orthostatism baPWV, and female(β=-0.055, P=0.01), upper limb orthostatism systolic blood pressure (β=-0.834, P<0.01), lower limbs orthostatism systolic blood pressure (β=0.708, P<0.01), lower limbs supine systolic blood pressure (β=0.099, P<0.01) and fasting blood glucose(β=-0.085, P<0.01) were associated with orthostatism ABI.

CONCLUSIONS

Orthostatism baPWV and ABI were significantly higher than those of supine's. Age, lower limbs orthostatism and supine systolic blood pressure, orthostatism and supine heart rate, body mass index were associated with orthostatism baPWV. Female, upper limb orthostatism systolic blood pressure, lower limbs orthostatism, supine systolic blood pressure and fasting blood glucose were associated with orthostatism ABI in the elderly.

Horizontal gene transfer does not occur between sFat-1 transgenic pigs and nontransgenic pigs

We previously generated and characterized synthesized fatty acid desaturase-1 (sFat-1) transgenic pigs that had increased concentrations of ω-3 unsaturated fatty acid in their meat. The objective was to assess whether the inserted foreign gene in sFat-1 transgenic pigs was able to transfer and integrate into the genome of nontransgenic pigs by suckling or mating. Tests for suckling-mediated horizontal gene transfer (HGT) included sFat-1 transgenic sows nursing nontransgenic piglets and sFat-1 transgenic piglets suckling nontransgenic sows. Tests for mating-mediated HGT were performed by male sFat-1 transgenic pigs mated with nontransgenic females and female sFat-1 transgenic pigs mated with nontransgenic males. Polymerase chain reaction was used to detect the sFat-1 gene fragment in various tissues sampled from nontransgenic pigs. The foreign target gene sFat-1 was not detected in the genomic DNA of various tissues and organs sampled from nontransgenic pigs. Therefore, we concluded that HGT from transgenic pigs to wild type pigs via suckling or mating was unlikely.

The predicting study for chromatographic retention index of saturated alcohols by MLR and ANN

A QSRR method was followed to relate the observed Kovats retention indexes of saturated alcohol compounds with their molecular connectivity indices by means of multilinear regression analysis and artificial neural networks technique. The alcohols included linear, branched with hydroxyl group on a primary, secondary, or tertiary carbon atom. At first, models were generated for six OV (Ohio Valley) series columns separately, with high value of R and F statistics. Then a combined model, added a polarity term of stationary phase (M), was also developed for all these columns, and the result was satisfactory. For comparison, the neural network of BP algorithm was applied, and it was found that the neural network could exceed the level of the multiple regression method. The stability and validity of both models were tested by cross-validation technique and by prediction response values for the prediction set.

Factors Influencing Lesion Detection in SPECT Lung Images

An earlier localization ROC (LROC) study that found attenuation correction (AC) degraded the detection of solitary pulmonary nodules (SPN) in hybrid SPECT lung images had several potential shortcomings related to the simulation methods. We sought to address these issues with a revised LROC study. Clinical Tc-99m NeoTect scans acquired with a simultaneous transmission-emission protocol defined the normal cases in a single-slice LROC study. Abnormal cases contained a simulated 1-cm lung lesion. Four rescaled-block-iterative EM (RBI) reconstruction strategies applied: 1) AC, scatter correction (SC), and resolution compensation (RC); 2) AC only; 3) RC only; and 4) no corrections (NC). Images from these strategies underwent 3D Gaussian post-smoothing. Performances were defined by the average area under the LROC curve obtained from three human observers. The strategy ranking in order of decreasing performance was: 1) RBI with RC; 2) RBI with all corrections; 3) RBI with AC; and 4) RBI with no corrections. A multireader-multicase (MRMC) analysis only found significant patient and patient-strategy effects. The conflicting results concerning AC from this study and the previous one may revolve around lesion masking effects, which, by design, were not a factor in the current study.

Regional cerebral blood flow changes in drug-resistant depressed patients following treatment with transcranial magnetic stimulation: a statistical parametric mapping analysis

Changes of regional cerebral blood flow (rCBF) in five drug-resistant depressed patients were examined by single photon emission computed tomography (SPECT) with 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) before and after treatment with transcranial magnetic stimulation (TMS). The SPECT images were analysed with the Statistical Parametric Mapping (SPM) package. TMS administered in the region of the left dorsolateral prefrontal cortex (DLPFC) of the depressed patients was associated with an increase of rCBF at a focal region some distance from the stimulation site. No change was observed at any other remote region.

A phosphotyrosine displacement mechanism for activation of Src by PTPalpha

Protein tyrosine phosphatase alpha (PTPalpha) is believed to dephosphorylate physiologically the Src proto-oncogene at phosphotyrosine (pTyr)527, a critical negative-regulatory residue. It thereby activates Src, and PTPalpha overexpression neoplastically transforms NIH 3T3 cells. pTyr789 in PTPalpha is constitutively phosphorylated and binds Grb2, an interaction that may inhibit PTPalpha activity. We show here that this phosphorylation also specifically enables PTPalpha to dephosphorylate pTyr527. Tyr789-->Phe mutation abrogates PTPalpha-Src binding, dephosphorylation of pTyr527 (although not of other substrates), and neoplastic transformation by overexpressed PTPalpha in vivo. We suggest that pTyr789 enables pTyr527 dephosphorylation by a pilot binding with the Src SH2 domain that displaces the intramolecular pTyr527-SH2 binding. Consistent with model predictions, we find that excess SH2 domains can disrupt PTPalpha-Src binding and can block PTPalpha-mediated dephosphorylation and activation in proportion to their affinity for pTyr789. Moreover, we show that, as predicted by the model, catalytically defective PTPalpha has reduced Src binding in vivo. The displacement mechanism provides another potential control point for physiological regulation of Src-family signal transduction pathways.

Apoptosis in rat erectile tissue induced by castration

AIM

To investigate the effect of androgen on the structure of corpus cavernosum.

METHODS

Thirty mature rats were randomized into 3 groups, i.e., simple castration, castration with testosterone (T) supplementation and sham-operated controls. One week after operation, the animals were sacrificed and corpora cavenosa harvested. Apoptosis was detected with the in situ end labeling (ISEL) techniques and DNA fragment analysis.

RESULTS

The apoptotic rate was 4.19% in the simple castrated rats, 0. 2% in castrated rats supplemented with T and 0.14% in the controls. Significant difference was found between the simple castrates and other two groups (P < 0.01). When comparing the T-supplementation group with the controls, there was no statistical difference (P > 0.05).

CONCLUSION

Castration induced apoptosis in rat corpus cavernosum, that could be prevented by T supplementation. It suggests that androgen plays an important role in maintaining the structure of corpus cavernosum.

Identification of 2,3-butanedione monoxime hydrogenation products by gas chromatography-mass spectrometry in an ion trap mass spectrometer

The reduced products of 2,3-butanedinone monoxime by reaction with hydrogen in the presence of homogeneous catalysts were identified by gas chromatography coupled to an ion trap mass spectrometer operating either in the electron impact or chemical ionization mode. The major hydrogenation products were found to be several heterocyclic nitrogen-containing compounds: tetramethylpyrazine, 2,4-dimethyl-3-ethylpyrrole, 3,4,5-trimethylpyrazole, 2,5-dimethyl-1-propylpyrrole, 3-acetyl-2,4-dimethylpyrrole, 3,5-dimethyl-4-allypyrazole and tetramethylpyrazine N-monoxide.

Regeneration of neuronal nitric oxide synthase (nNOS)-containing nerve fibers in rat corpus cavernosum

AIM

To investigate the effect of cavernous nerve injury on the nNOS-containing nerve fibers in rat corpus cavernosum.

METHODS

Thirty-three male SD rats were randomized into 3 groups: 5 rats underwent pelvic exploration without transection of cavernous nerve as the sham-operated controls, the unilateral injury group (14 rats) had the cavernous nerve cut on one side, and the bilateral injury group (14 rats) had the nerves cut on both sides. Corpora cavernosa were harvested at the 3rd week and 6th month after surgery. nNOS-positive nerve fibers were examined with strepavidin peroxidase immunohistochemistry techniques (SP method).

RESULTS

After bilateral ablation, the nNOS-positive nerve fibers were significantly decreased at both the 3rd week (17 +/- 4) and the 6th month (16 +/- 4). For the unilateral injury group, the nNOS-positive nerve fibers were similarly decreased on the side of the neurotomy at the 3rd week (18 +/- 6), but by the 6th month, the number increased significantly (61 +/- 9) and approximated the level on the contralateral side (81 +/- 13).

CONCLUSION

In rats after unilateral cavernous nerve ablation, nNOS-containing nerve fibers might regenerate 6 months after operation, but regeneration did not occur in animals with bilateral cavernous nerve injury. Results suggest that during pelvic radical surgery, the cavernous nerve should be preserved at least on one side in order to accomplish adequate regeneration.

Effect of Corticosteroids on Rabbit Corneal Keratocytes After Photorefractive Keratectomy

BACKGROUND

To determine the corticosteroid effect on the activity and repopulation of keratocytes after photorefractive keratectomy (PRK).

METHODS

A 193-nm excimer laser (VISX Twenty/Twenty) created a central ablation depth of 22 microns (diameter:5 nm) on 22 corneas of 16 albino rabbits. Two ablated eyes were examined 6 hours following PRK. Twelve eyes received no postoperative corticosteroids and eight were treated with topical fluoromethalone for 3 months. Corneas were examined 1, 3, 6, and 12 months after PRK by immunofluorescence and transmission electron microscopy.

RESULTS

Corticosteroids reduced haze (p=0.02), but all corneas (treated or untreated) cleared 6 months after PRK. Keratocytes were absent from the anterior 100 microns of the stroma 6 hours after PRK. However, the number and activity of keratocytes were significantly greater in this area in untreated corneas at 1 month and then gradually decreased. By 6 and 12 months, the number of keratocytes approached controls. Treated corneas had fewer keratocytes than either controls or untreated eyes (p<0.01) and by 3 months, a subepithelial acellular zone of 30 to 50 microns thickness appeared and persisted until at last 12 months after PRK.

CONCLUSIONS

Corticosteroids have a transient effect in reducing haze and seem to inhibit keratocyte movement, leading to an acellular subepithelial region beneath the ablated area.

Expression of receptor-like protein tyrosine phosphatase alpha in rat embryo fibroblasts activates mitogen-activated protein kinase and c-Jun

Anti-c-Src and anti-phosphotyrosine immunoprecipitates from receptor-like protein tyrosine phosphatase alpha (PTP alpha)-transfected and control rat embryo fibroblasts contain a 39-kDa phosphoprotein (p39) whose phosphorylation is enhanced by PTP alpha expression. The p39 that co-immunoprecipitates with c-Src has been identified as c-Jun by immunological and functional criteria; it is recognized by several different anti-c-Jun antibodies and binds to a c-Jun recognition element-containing oligonucleotide. Whereas the association of c-Src and c-Jun is unexpected, it may be of significance in PTP alpha signaling since we have previously demonstrated that c-Src is activated by PTP alpha (Zheng, X. M., Wang, Y., and Pallen, C. J. (1992) Nature 359, 336-339. Examination of c-Jun activity in these fibroblasts demonstrates that c-Jun DNA binding activity and c-Jun-mediated transcription of a chloramphenicol acetyltransferase reporter gene are elevated in PTP alpha-expressing cells. In addition to c-Jun activation, mitogen-activated protein kinase is activated in PTP alpha-expressing cells and translocated to the nuclei of these cells. The nuclear localization of activated mitogen-activated protein kinase and c-Jun suggests that their activation represents downstream events in the receptor-like PTP alpha-initiated signaling pathway(s).

Cell transformation and activation of pp60c-src by overexpression of a protein tyrosine phosphatase

The kinase activity of pp60c-src is specifically and transiently increased during mitosis and repressed during interphase. Loss of cell-cycle control of pp60c-src occurs on mutation of Tyr527 to Phe or when pp60c-src is associated with polyoma middle-T-antigen, and these conditions result in cell transformation or tumorigenesis. In both cases, pp60c-src has elevated kinase activity which is maintained throughout the cell cycle and accompanied by dephosphorylation of the carboxy-terminal negative regulatory Tyr527 site, or mimicry of Tyr527 dephosphorylation in the case of the mutant. Here we report that overexpression of the receptor-like protein tyrosine phosphatase PTP alpha results in persistent activation of pp60c-src kinase, with concomitant cell transformation and tumorigenesis. In PTP alpha-overexpressing cells, the pp60c-src kinase activation is accompanied by dephosphorylation at Tyr527, and direct dephosphorylation of this site by purified PTP alpha occurs in vitro. Our results suggest that PTP alpha is involved in the regulation of cell proliferation, exerting at least some of its effects through pp60c-src kinase, and has oncogenic capability when overexpressed.

[Clinical application and experimental study of homologous-cartilage implantation]

On the basis of 124 cases of homologous-cartilage grafts, the changes of host's tissue structure and immune active cells around the homologous-cartilage were studied. Slices of implantation at different time were investigated by histologic, histochemical, immunopathologic and ultrastructural methods. The results show that the rejection phenomena of homologous-cartilage grafts may be the process of substitution of bone for cartilage, rather than the process of absorption and there are no influences on supporting framework of homologous-cartilage grafts.

Sequencing and expression of complementary DNA for the general transcription factor BTF3

The initiation of transcription of eukaryotic genes involves the ordered assembly of a multiprotein complex on proximal promoter elements such as the TATA box. In addition to RNA polymerase II (otherwise RNA pol II, RNA polymerase B), four general transcription factors are required for initiation of transcription: BTF1 (also referred to as TFIID) which has recently been cloned from yeast, BTF2, BTF3 and STF. The first step in assembly of the initiation complex is the stable binding of BTF1 to the TATA box, which is facilitated by STF. Neither BTF2 nor BTF3 bind directly to the promoter proximal elements, but BTF3 can form a stable complex with RNA pol II. We recently purified BTF3, which is a protein of relative molecular mass 27,000, but further studies have been hampered by its low abundance in cells. On the basis of sequences from peptides of BTF3, we have now cloned two complementary DNAs, one for a protein (BTF3a) with all the characteristics of purified BTF3, and one for a shorter protein (BTF3b) lacking the first 44 residues of BTF3a and which is transcriptionally inactive, despite its ability to bind RNA pol II.

[AIDS with subacute encephalitis as its first symptom]

This paper reports a case of AIDS whose first symptom was SAE. The main clinic characteristics were epilepsy, and brain atrophy. In addition, there were also other features in this case, such as multiorgan damage, weight loss, fever and diarrhea. The patient's serum showed a positive result to anti HTLV-III, and TH:Ts = 0.22 less than 1. According to the direct pathogenic effect of HIV on CNS, which is similar to SV, we made the diagnosis that it was the first case of SAE of AIDS in China. We also made a preliminary exploration into the cause of low Ig in the case.

Immunopathological study on human cartilage allografts

The fate of human cartilage allografts and the mechanism of its kinetical development were studied histopathologically and immunohistologically. After transplantation, the grafts underwent necrosis, calcification and were partially invaded by osteoplastic tissue of the host and eventually replaced by bone tissue. Thus, the contour of the transplanted cartilage was kept partially by the living cartilage and the newly-formed osseous tissue. The grafts were surrounded initially by granular tissue and then by scar tissue, in which numerous T cells and a few macrophage infiltrates were noted. In T cells, T4+ lymphocytes predominated but T8+ cells accounted for a small number. B cells were not found within the infiltrates. Most of the infiltrating cells expressed 12 antigens, indicating that the majority of T cells were activated. It was concluded that T lymphocytes mediated cellular immunity played an important role. The chondrocytes of the cartilage did not express HLA I and II antigens before transplantation, but one month later, the living chondrocytes became HLA I and II antigens positive, and the antigen expression became stronger with the elapse of time; this might be induced by lymphokins, especially by interferon produced by the infiltrating lymphocytes. Such an expression of MHC antigens on chondrocytes might contribute to the further enhancement of immunorejection.

A general transcription factor forms a stable complex with RNA polymerase B (II)

A general transcription factor (BTF3) has been purified from HeLa whole cell extracts and shown to be required for accurate initiation of transcription from the adenovirus-2 major late promoter (Ad2MLP) and other RNA polymerase class B promoters. We show that purified BTF3 (27 kd) binds to RNA polymerase B (II), forming a complex that is transcriptionally active. We found no evidence that purified BTF3 interacts with DNA or is required for the formation of the stable preinitiation complex.

Purification of a factor specific for the upstream element of the adenovirus-2 major late promoter

Stimulation of in vitro transcription by the upstream element (UE) of the adenovirus-2 major late promoter (Ad2MLP) involves a specific trans-acting factor present in a HeLa whole-cell extract. By following its transcriptional stimulatory activity and its DNase I footprint on the Ad2MLP-UE, we have purified this factor to greater than 10% purity and separated it from RNA polymerase B and the general transcription factors required for transcription from the Ad2MLP.