[HVPG minimally invasive era: exploration based on forearm venous approach]

Objective: The transjugular or transfemoral approach is used as a common method for hepatic venous pressure gradient (HVPG) measurement in current practice. This study aims to confirm the safety and effectiveness of measuring HVPG via the forearm venous approach. Methods: Prospective recruitment was conducted for patients with cirrhosis who underwent HVPG measurement via the forearm venous approach at six hospitals in China and Japan from September 2020 to December 2020. Patients' clinical baseline information and HVPG measurement data were collected. The right median cubital vein or basilic vein approach for all enrolled patients was selected. The HVPG standard process was used to measure pressure. Research data were analyzed using SPSS 22.0 statistical software. Quantitative data were used to represent medians (interquartile ranges), while qualitative data were used to represent frequency and rates. The correlation between two sets of data was analyzed using Pearson correlation analysis. Results: A total of 43 cases were enrolled in this study. Of these, 41 (95.3%) successfully underwent HVPG measurement via the forearm venous approach. None of the patients had any serious complications. The median operation time for HVPG detection via forearm vein was 18.0 minutes (12.3~38.8 minutes). This study confirmed that HVPG was positively closely related to Child-Pugh score (r = 0.47, P = 0.002), albumin-bilirubin score (r = 0.37, P = 0.001), Lok index (r = 0.36, P = 0.02), liver stiffness (r = 0.58, P = 0.01), and spleen stiffness (r = 0.77, P = 0.01), while negatively correlated with albumin (r = -0.42, P = 0.006). Conclusion: The results of this multi-centre retrospective study suggest that HVPG measurement via the forearm venous approach is safe and feasible.

[The application of ultrasound in the diagnosis of small bowel volvulus in adults]

Objective: To analyze the ultrasound characteristics of small bowel volvulus among adults and to investigate the value of ultrasound in the diagnosis of small bowel volvulus. Methods: Totally 34 adults with small bowel volvulus confirmed by clinical diagnosis or surgery and who underwent ultrasound examination at Peking Union Medical College Hospital from August 2017 to October 2022 were enrolled, including 19 males and 15 females, aged (55.0±21.8) years (range: 19 to 94 years). The clinical characteristics, CT images and ultrasound images of the patients were retrospectively reviewed, and the ultra, sound features of small bowel volvulus and its diagnostic efficacy were analyzed. Results: Abdominal pain was the typical clinical symptom of all patients. Other symptoms included 21 cases of abdominal distension, 19 cases of nausea and vomiting, and 13 cases of cessation of passage of stool or flatus. Eight patients had signs of peritonitis and 22 patients had abnormal bowel sounds. Twenty patients had a history of abdominal surgery. Twenty-seven patients underwent surgery for intestinal obstruction, and the remaining 7 patients improved after conservative treatment. All cases were evaluated by ultrasound, 11 cases showed a "whirl sign" and were diagnosed as small bowel volvulus, the diagnostic accuracy rate was 32.4% (11/34), ultrasound simultaneously diagnosed intestinal obstruction in 21 cases, 17 cases of abdominal effusion, 4 cases of intestinal wall thickening, 2 cases of abdominal mass, 1 case of intussusception, 1 case of right sided inguinal hernia. CT and ultrasound had a consistent positive discovery in 88.2% (30/34) of all the patients. Conclusion: Ultrasound is valuable in the diagnosis of small bowel volvulus and the evaluation of complications.

[Expert consensus on the biobank development of oral genetic diseases and rare diseases and storage codes of related biological samples from craniofacial and oral region]

The biological samples of oral genetic diseases and rare diseases are extremely precious. Collecting and preserving these biological samples are helpful to elucidate the mechanisms and improve the level of diagnose and treatment of oral genetic diseases and rare diseases. The standardized construction of biobanks for oral genetic diseases and rare diseases is important for achieving these goals. At present, there is very little information on the construction of these biobanks, and the standards or suggestions for the classification and coding of biological samples from oral and maxillofacial sources, and this is not conducive to the standardization and information construction of biobanks for special oral diseases. This consensus summarizes the background, necessity, principles, and key points of constructing the biobank for oral genetic diseases and rare diseases. On the base of the group standard "Classification and Coding for Human Biomaterial" (GB/T 39768-2021) issued by the National Technical Committee for Standardization of Biological Samples, we suggest 76 new coding numbers for different of biological samples from oral and maxillofacial sources. We hope the consensus may promote the standardization, and smartization on the biobank construction as well as the overall research level of oral genetic diseases and rare diseases in China.

[Alertness and task processing speed impairment status and influencing factors of young-middle aged men with obstructive sleep apnea hypopnea syndrome]

Objective: To investigate the alertness and task processing speed impairment status in young-mild aged men with obstructive sleep apnea hypopnea syndrome (OSAHS), and analyze its influencing factors. Methods: This prospective study recruited 251 snoring patients aged 18 to 59 (38.9±7.6) years in the Sleep Center of the Second Affiliated Hospital of Soochow University from July 2020 to September 2021 and all patients were diagnosed by polysomnography (PSG). Clinical information, Epworth Sleepiness Scale (ESS) and PSG date were collected. All patients were assessed with the Montreal Cognitive Assessment (MoCA) questionnaires, Mini-mental State Examination (MMSE) and Computerized Neurocognitive Assessment System which includes the reaction time of Motor Screening Task (MOT) for alertness, the reaction time of pattern recognition memory (PRM), spatial span (SSP) and spatial working memory (SWM) for task processing speed. Based on AHI tertiles, all patients were divided into Q1 group (AHI<15 times/h, n=79), Q2 group (15 times/h≤AHI<45 times/h, n=88), and Q3 group (AHI≥45 times/h, n=84). The characteristics of clinical information, ESS, PSG parameters and cognitive scores among three groups were compared. Multiple linear stepwise regression was conducted to analyze the influencing factors of cognitive impairment. Results: There were no statistically significant differences in age, years of education, history of smoking and drinking, and past disease history (except for the prevalence of hypertension) among the 3 groups (P>0.05). There were statistically significant among-group differences in the body mass index (BMI), ESS, prevalence of hypertension and complaints of daytime sleepiness (P<0.05). Compared with Q1 and Q2 group, the arousal index (ArI), oxygen desaturation index (ODI),the proportion of non-rapid eye movement phase 1 and 2 (N1+N2) and percentage of total sleep time with oxygen saturation level<90% (TS90) of Q3 group were higher (all P<0.05). In the cognitive assessment, there was no statistically significant difference in the MoCA total and individual scores and MMSE scores among the three groups (P>0.05). Compared with the Q1 group, the task processing speed and alertness were worse in Q3 group, as shown by slower PRM immediate and delayed reaction time, SSP reaction time and MOT reaction time (all P<0.05). The total time of SWM in Q2 group was slower than that in Q1 group (P<0.05). Multiple linear stepwise regression showed that years of education (β=-40.182, 95%CI:-69.847--10.517), ODI (β=3.539, 95%CI: 0.600-6.478) were the risk factors of PRM immediate reaction time. Age(β=13.303,95%CI: 2.487-24.119), years of education(β=-32.329, 95%CI:-63.162--1.497), ODI (β=4.515, 95%CI: 1.623-7.407) were the risk factors of PRM delayed reaction time. ODI was the risk factor of SSP reaction time (β=1.258, 95%CI: 0.379-2.137). TS90 was the risk factor of MOT reaction time (β=1.796, 95%CI: 0.664-2.928). Conclusions: The early cognitive impairment in young-mild aged OSAHS patients was manifested in decreased alertness and task processing speed, and intermittent nocturnal hypoxia was its influencing factor in addition to age and years of education.

[Effect of sleep spindle density on memory function in patients with obstructive sleep apnea hypopnea syndrome]

Objective: To explore the characteristics of sleep spindle density in nonrapid eye movement (NREM) stage 2 (N2) sleep and its effect on memory function in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: Patients who underwent polysomnography (PSG) examination due to snoring in the Second Affiliated Hospital of Soochow University from January to December 2021 were prospectively collected. A total of 119 male patients, aged 23-60 (37.4±7.3) years, were enrolled finally. According to the apnea hyponea index (AHI), the subjects were divided into a control group (AHI<15 times/h) of 59 cases and an OSAHS group (AHI≥15 times/h) of 60 cases. The basic information, general clinical data and PSG parameters were collected. Memory function scores were evaluated by using logical memory test (LMT), digit ordering test (DOT) and pattern recognition memory (PRM), spatial recognition memory (SRM) and spatial working memory (SWM) in CANTAB test. The number of N2 sleep spindles in leads left central area (C3) and right central area (C4) was counted by hand and the sleep spindle density (SSD) was calculated. The differences in the above indexes and N2 SSD were compared between the two groups. Shapiro-Wilk method, chi-squared test, Spearman correlation analysis and stepwise multivariate logistic regression analysis were used to investigate the influencing factors of memory scores in patients with OSAHS. Results: Compared with the control group, the proportion of the slow-wave sleep, the minimum blood oxygen saturation, the SSD in C3 of NREM2 stage and the SSD in C4 of NREM2 stage were lower in the OSAHS group. The body mass index (BMI), proportion of N2 sleep, oxygen reduction index, percentage of time with oxyhemoglobin saturation below 90% (TS90), maximum duration of apnea and respiratory effort-related arousal(RERA) were higher in the OSAHS group (all P<0.05). Compared with the control group, the immediate LMT score was lower, while the time for immediately completing PRM test, the total time for immediately completing SRM test and the time for delayed completing PRM test were longer in the OSAHS group, suggesting that the immediate logical memory, immediate visual memory, spatial recognition memory and delayed visual memory were worse in the OSAHS group. Stepwise multivariate logistic regression analysis revealed that the number of years of education (OR=0.744, 95%CI 0.565-0.979, P=0.035), maximum duration of apnea (OR=0.946, 95%CI 0.898-0.997, P=0.038) and N2-C3 SSD (OR=0.328, 95%CI 0.207-0.618, P=0.012) and N2-C4 SSD (OR=0.339, 95%CI 0.218-0.527, P=0.017) were independent factors affecting the immediate visual memory. The AHI (OR=1.449, 95%CI 1.057-1.985, P=0.021), N2-C3 SSD (OR=0.377, 95%CI 0.246-0.549, P=0.009), and N2-C4 SSD (OR=0.400, 95%CI 0.267-0.600, P=0.010) were independent factors affecting delayed visual memory. Conclusions: The decrease in SSD is associated with impaired memory function in patients with moderate-severe OSAHS, which is manifested as impairment of immediate visual memory and delayed visual memory. This suggests that changes of sleep spindle wave in N2 may be an electroencephalographic biomarker for assessing cognitive impairment in OSAHS patients.

Unintrusive multi-cancer detection by circulating cell-free DNA methylation sequencing (THUNDER): development and independent validation studies

BACKGROUND

Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) aimed to evaluate the performance of ELSA-seq, a previously described cfDNA methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary and pancreas.

PATIENTS AND METHODS

A customized panel of 161,984 CpG sites was constructed and validated by public and in-house (cancer: n=249; non-cancer: n=288) methylome data, respectively. The cfDNA samples from 1,693 participants (cancer: n=735; non-cancer: n=958) were retrospectively collected to train and validate two multi-cancer detection blood test models (MCDBT-1/2) for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1,010 participants (cancer: n=505; non-cancer: n=505). Simulation using the cancer incidence in China was applied to infer stage-shift and survival benefits to demonstrate the potential utility of the models in the real world.

RESULTS

MCDBT-1 yielded a sensitivity of 69.1% (64.8%‒73.3%), a specificity of 98.9% (97.6%‒99.7%) and tissue origin accuracy of 83.2% (78.7%‒87.1%) in the independent validation set. For early stage (I‒III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%‒65.0%). In the real-world simulation, MCDBT-1 achieved the sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%‒46.4%, and increasing 5-year survival rate by 33.1%‒40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance.

CONCLUSION

In this large-scale clinical validation study, MCDBT-1/2 models showed a high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.

[Status of HVPG clinical application in China in 2021]

Objective: The investigation and research on the application status of Hepatic Venous Pressure Gradient (HVPG) is very important to understand the real situation and future development of this technology in China. Methods: This study comprehensively investigated the basic situation of HVPG technology in China, including hospital distribution, hospital level, annual number of cases, catheters used, average cost, indications and existing problems. Results: According to the survey, there were 70 hospitals in China carrying out HVPG technology in 2021, distributed in 28 provinces (autonomous regions and municipalities directly under the central Government). A total of 4 398 cases of HVPG were performed in all the surveyed hospitals in 2021, of which 2 291 cases (52.1%) were tested by HVPG alone. The average cost of HVPG detection was (5 617.2±2 079.4) yuan. 96.3% of the teams completed HVPG detection with balloon method, and most of the teams used thrombectomy balloon catheter (80.3%). Conclusion: Through this investigation, the status of domestic clinical application of HVPG has been clarified, and it has been confirmed that many domestic medical institutions have mastered this technology, but it still needs to continue to promote and popularize HVPG technology in the future.

[Screening and analysis of prognostic factors of repairing single missing tooth by autotransplantation of teeth]

Objective: To screen and analyze the factors affecting the prognosis of replacing single missing tooth by autograft tooth, so as to provide reference for clinical judgment of surgical prognosis. Methods: A total of 176 patients (188 teeth) underwent autotransplantation of teeth in the Department of Oral & Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University from January 2017 to December 2019, including 85 teeth of males and 103 teeth of females were involved. The age was (33.0±9.8) years (16-65 years). The possible factors affecting the prognosis of replacing single missing tooth by autograft tooth were summarized and grouped, and the clinical and imaging data were recorded and judged. The surgical records and photographic data from the patients' previous medical records were retrospectively analyzed. The survival analysis method was used for statistical analysis to screen out the factors affecting the cumulative survival rate of transplanted teeth. Results: The 5-year cumulative survival rate of 188 transplanted teeth was 88.4%. Univariate Log-Rank analysis showed that age (P<0.001), sex (P=0.008), smoking (P<0.001), position of recipient area (P<0.001), height of alveolar bone in recipient area (P<0.001), time of donor tooth in vitro (P<0.001), use of donor model (P<0.001) and initial stability (P<0.001) were significantly correlated with cumulative survival rate of transplanted teeth. Multivariate Cox proportional hazard regression analysis showed that smoking (β=-2.812, P=0.049), alveolar bone height (β=1.521, P=0.020), donor time (β=-2.001, P=0.019), use of donor model (β=1.666, P=0.034) and initial stability (β=-1.417, P=0.033) were significantly correlated with the cumulative survival rate of transplanted teeth. Conclusions: The prognosis of autogenous tooth transplantation can be predicted by smoking, height of alveolar bone in recipient area, time of donor teeth in vitro, use of donor model and initial stability. Good prognosis of transplanted teeth can be obtained by using donor model during operation, reducing the time of donor teeth in vitro, taking effective methods to restore alveolar bone height, maintaining good initial stability, and good oral health education after operation.

[Ultrasound features and clinical characteristics of intestinal ischemia secondary to acute mesenteric venous thrombosis]

Objective: To examine the ultrasound features and clinical characteristics of the intestinal ischemia secondary to acute mesenteric venous thrombosis (AMVT). Methods: From January 2016 to June 2019, 11 patients were diagnosed as intestinal ischemia secondary to AMVT confirmed by surgical pathology or CT in Peking Union Medical College Hospital. The patients included 7 males and 4 females, aging of (52.8±11.9) years (range: 34 to 81 years).The clinical characters and ultrasound features were retrospectively reviewed. Results: Abdomen pain was the chief complaint of all patients. Other complaints include 2 cases of blood in the stool, 1 case of hematemesis, 2 cases of vomiting, 1 case of diarrhea. Six patients showed rebound pain on physical examination. All patients had elevated white blood cell account and D-Dimer. Nine patients had a thrombosis in the portal vein simultaneously. All 11 patients underwent the CT scan including 10 contrast-enhanced CT. Mesenteric venous thrombosis was detected in 10 cases who underwent contrast-enhanced CT imaging. On CT imaging, 11 patients demonstrated intestinal wall thicken, 5 patients showed intestinal dilation. Eight patients underwent superior mesenteric venous ultrasound examination. Of them, 7 patients were correctly diagnosed as AMVT. Of the 10 patients who underwent abdominal ultrasound, 5 patients showed intestinal lesions including intestinal wall thicken in 4 patients and intestinal dilation in 1 patient. Peritoneal fluid was detected in 10 patients by ultrasound, which was consistent with CT. Ten patients underwent surgical procedures while 1 patient received conservative treatment. Conclusion: Ultrasound is an accurate imaging method in diagnosing superior mesenteric vein thrombosis and can detect intestinal wall thickening, intestinal dilation, and peritoneal fluid.

[The impact of carbapenem-resistance Pseudomonas aeruginosa infections on mortality of patients with hematological disorders]

Objective: To assess the risk factors for mortality and clinical outcome of carbapenem-resistant Pseudomonas aeruginosa (CRPA) infections in patients with hematological disorders. Methods: The data of in-patients with hematological disorders infected by CRPA or carbapenem-susceptible Pseudomonas aeruginosa (CSPA) were recorded in a seven-year retrospective cohort study. Risk factors for CRPA infections and impact of on mortality were identified. The primary end point was 30-day all-cause mortality. Results: A total of 81 patients with PA infections were included in the study, including 58 CSPA and 23 CRPA. Most of the primary diseases were acute leukemia or lymphoma (79.0%, 64/81). The median absolute neutrophil count at infection onset was 0.24×10(9)/L. Independent risk factors associated with carbapenem-resistance included longer duration of hospital stay (P=0.013, OR=1.045) and carbapenem exposure one month prior to infections (P=0.005, OR=8.132). The 30-day all-cause mortality of the whole cohort was 29.6%(24/81), and 30-day attributable mortality was 13.6%(11/81). Pulmonary infection was the leading cause of death, accounting for 41.7%(10/24). The adjusted 30-day mortality rate was significantly higher in patients with CRPA compared with CSPA [60.9%(14/23) vs. 17.2%(10/58), P<0.001, respectively]. CRPA infection was an independent prognostic factor for 30-day mortality(P=0.011, OR=5.427). Other factors included old age, longer duration of neutropenia and poor functional performance. Conclusions: Patients with hematological disorders have high mortality rate and poor prognosis caused by CRPA infections, which mainly develop in lungs.

Rehmannia glutinosa oligosaccharide induces differentiation of bone marrow mesenchymal stem cells into cardiomyocyte-like cells

The aim of this study was to observe the effect of Rehmannia glutinosa oligosaccharide (RGO) on differentiation of bone marrow mesenchymal stem cells (MSCs) into cardiomyocyte-like cells . Rat MSCs were isolated, treated, and grouped as follows: RGO treatment group, 5-azacytidine (5-aza) treatment group, RGO + 5-aza treatment group, and control group. Following a four-week induction period, cardiac troponin I (cTnI) levels in MSCs were quantified by chemiluminescence, and the levels of myocardial enzymes creatine kinase (CK) and creatine kinase isoenzyme-MB (CK-MB) were measured using a dry chemistry analyzer. The cTnI- and connexin 43 (Cx43)-positive MSC population was identified by immunofluorescence, and expression levels of cTnI and Cx43 were analyzed by western blots. Following induction, cTnI, CK, and CK-MB levels were significantly higher in the RGO + 5-aza group as compared with the RGO and 5-aza groups (P < 0.05). In addition, fluorescence intensity of cTnI and Cx43 was higher in the RGO + 5-aza group as compared with the RGO and 5-aza groups. No cTnI- or Cx43-positive cells were detected in the control group. Western blot analysis further confirmed that cTnI and Cx43 were not expressed in the control group, while cTnI and Cx43 was higher in the RGO + 5-aza group than in the RGO and 5-aza groups. These results suggest that MSCs can be induced by RGO to differentiate into cardiomyocyte-like cells in vitro, and that RGO in combination with 5-aza enhance differentiation of MSCs.

Marker-assisted selection of Fusarium wilt-resistant and gynoecious melon (Cucumis melo L.)

In this study, molecular markers were designed based on the sex determination genes ACS7 (A) and WIP1 (G) and the domain in the Fusarium oxysporum-resistant gene Fom-2 (F) in order to achieve selection of F. oxysporum-resistant gynoecious melon plants. Markers of A and F are cleaved amplified polymorphic sequences that distinguish alleles according to restriction analysis. Twenty F1 and 1863 F2 plants derived from the crosses between the gynoecious line WI998 and the Fusarium wilt-resistant line MR-1 were genotyped based on the markers. The results showed that the polymerase chain reaction and enzyme digestion results could be effectively used to identify plants with the AAggFF genotype in F2 populations. In the F2 population, 35 gynoecious wilt-resistant plants were selected by marker-assisted selection and were confirmed by disease infection assays, demonstrating that these markers can be used in breeding to select F. oxysporum-resistant gynoecious melon plants.

CpG ODN-induced matrix metalloproteinase-13 expression is mediated via activation of the ERK and NF-κB signalling pathways in odontoblast cells

AIM

To investigate the effects of CpG ODN (CpG oligodeoxynucleotides) to model the action of bacterial challenge on pulpal matrix metalloproteinase-13 (MMP-13) expression and elucidate the associated intracellular signalling pathways.

METHODOLOGY

Real-time PCR was used to detect the effects of CpG ODN on MMP-13 mRNA expression levels in a murine odontoblast-lineage cell line (OLCs). The possible involvement of TLR9/MyD88, NF-κB or MAPK pathways involved in the CpG ODN-induced MMP-13 expression was examined by real-time PCR, transient transfection, luciferase activity assay and ELISA. Western blotting was performed to assay the phosphorylation of ERK at a range of time points.

RESULTS

MMP-13 was constitutively expressed in OLCs, and their exposure to CpG ODN significantly increased MMP-13 expression. Pre-treatment of OLCs with the inhibitory peptide MyD88, or chloroquine, attenuated the CpG ODN-induced expression of MMP-13. Treatment of the OLCs with CpG ODN increased NF-κB-luciferase activity. This activity was decreased by the over-expression of a nondegrading mutant of IκBα (IκBαSR), although enhanced by the over-expression of NF-κB p65. MMP-13 expression induced by CpG ODN was markedly suppressed by NF-κB inhibitors (pyrrolidine dithiocarbamate, PDTC), IκBα phosphorylation inhibitors (Bay 117082) or IκB protease inhibitor (L-1-tosylamido-2-phenylethyl chloromethyl ketone, TPCK). The inhibitor of ERK1/2, U0126, but not inhibitors of p38 MAPK and JNK, SB203580 and SP600125, decreased CpG ODN-mediated MMP-13 expression.

CONCLUSION

The CpG ODN-induced MMP-13 expression in OLCs is mediated through TLR9, NF-κB and the ERK pathway indicating that potentially the recognition of CpG ODN by TLR9 on odontoblasts may regulate the remodelling of injured dental pulp and hard tissues by inducing MMP-13 expression.

Modulation by nucleotides of binding sites for [3H]glibenclamide in rat aorta and cardiac ventricular membranes

Radioligand binding techniques were employed to determine the modulation by nucleotides of the specific [3H]glibenclamide (Gli) binding to rat aortic and cardiac ventricular preparations. Saturation analysis revealed a single binding site with K(D) value of 31.3 nM and Bmax of 180 fmol/mg wet weight in aortic preparations. We also observed that [3H]Gli bound reversibly and specifically to cardiac membranes. Unlabeled glibenclamide displaced [3H]Gli-specific binding of cardiac membranes completely with K(I) of 54.4 nM. In cardiac membranes, adenosine triphosphate (ATP), adenosine diphosphate (ADP), and uridine diphosphate (UDP) (from 0.01-5 mM) concentration dependently inhibited [3H]Gli binding independent of Mg2+. The values of K(I) were 0.47, 0.22, and 0.58 mM, respectively. However, in aortic preparations, [3H]Gli-specific binding was increased by ATP of 5 and 10 mM and showed a biphasic response to ADP. At concentrations to 1 mM, ADP inhibited binding; above 5 mM, the specific [3H]Gli binding was increased. UDP did not alter the binding up to 5 mM. In the presence of Mg2+ (20 mM), the inhibitory effects of ATP (0.01-1 mM) or ADP (0.01-5 mM) on the binding in cardiac membranes were abolished, whereas the facilitatory effects of ATP or ADP in aortic preparations were strengthened. Analysis of kinetics showed that the time of [3H]Gli association and dissociation in cardiac and aortic preparations was monophasic. The association was delayed with dissociation unchanged by ATP, ADP, and UDP of 1 mM, respectively, in cardiac membranes. In aorta, however, at the same concentration ATP accelerated association and retarded dissociation and vice versa for ADP. Association and dissociation were not changed by UDP of 5 mM. We conclude that ATP, ADP, and UDP are all major allosteric modulators of K(ATP) channels and they affect the antagonist binding to heart (sulfonylurea receptor 2A) and aorta (sulfonylurea receptor 2B) differently.

The binding domain structure of retinoblastoma-binding proteins

The retinoblastoma gene product (Rb), a cellular growth suppressor, complexes with viral and cellular proteins that contain a specific binding domain incorporating three invariant residues: Leu-X-Cys-X-Glu, where X denotes a nonconserved residue. Hydrophobic and electrostatic properties are strongly conserved in this segment even though the nonconserved amino acids vary considerably from one Rb-binding protein to another. In this report, we present a diagnostic computer pattern for a high-affinity Rb-binding domain featuring the three conserved residues as well as the conserved physico-chemical properties. Although the pattern encompasses only 10 residues (with only 4 of these explicitly defined), it exhibits 100% sensitivity and 99.95% specificity in database searches. This implies that a certain pattern of structural and physico-chemical properties encoded by this short sequence is sufficient to govern specific Rb binding. We also present evidence that the secondary structural conformation through this region is important for effective Rb binding.

Localization of fibronectin in the frog skin

In this review, we present structural and ultrastructural localizations of fibronectin (FN) in the larval and adult skin of the frog (Rana esculenta) either in in vivo or in in vitro conditions. The ventral skin of the tadpole contains membrane-associated FN-plaques disposed around the epidermal and dermal cells during their climactic rearrangement. Moreover, lines of fibrillar FN are detected inside the breaks opened in the derived collagen. The ventral skin of the adult frog reveals FN distributed in the three superimposed tissues forming the skin, i.e. the epidermis, the dermis and the subcutaneous tissue. In vivo, the epidermis is devoid of FN except for the mitochondria-rich cells (MRCs) which contain FN cytoplasmic granules. The dermis reveals two distinct collagenous networks showing FN localizations. A vertically-oriented network formed by thick tracts contains axis of fibrillar FN connecting the upper dermis devoid of FN to the FN-rich subcutaneous tissue. In contiguity with an horizontally-oriented network comprises thin tracts formed by clear spaces separating the superimposed collagen bundles of the dermal stratum compactum. These tracts contain aligned FN-granules. Inside the thick and thin tracts, the dermal and pigment cells present membrane-associated In vitro (in organ culture conditions) MRCs of the epidermis maintain their FN localization and, in addition, the stratum germinativum cells show cytoplasmic FN granules. Epidermal cells, in the vicinity of the cut edges of the cultivated skin fragment, modify their shape and acquire membrane-associated FN-plaques located between desmosomes. The FN localizations in these two collagenous networks of the dermis remain unchanged. In the same way, the FN-rich subcutaneous tissue is unmodified. In summary, the FN distribution in the larval skin is related to the cell rearrangement during the metamorphic climax, and, in the adult skin to the cell migration during the wound healing process and the pigment cell patterning. The cell migration is demonstrated, in organ culture conditions, by antiFN serum used as an experimental tool. FN is an important substrate used in the dermal breaks of the larval skin, and in the dermal tracts of the adult skin, both allowing the dermal and pigment cell migration.

Redistribution of fibronectin and keratin localization patterns in early wounded confluent PtK2 cells

Single and double-label immunofluorescence were used to study the fibronectin (FN) and keratins (Ks) localization patterns in early wounded confluent PtK2 cells. A time-course study (0 hr, 2 hr, 6 hr and 24 hr) gives the following results: before wounding, the FN localizations of confluent cells are composed of curved and sometimes branched strands or fibrils. The Ks network is formed by radial fluorescent filaments connecting the Ks centers near the nuclei with a linear fluorescence underlying the cell membrane. Two hr after, the FN localizations are redistributed at the cell-cell contact areas. The radial Ks filaments are compacted around the nuclei, some of them delineate the cytoplasmic periphery of the wounded cells. Six hr later, the method shows redistributed FN localizations at the cell-cell contact areas. An alveolar pattern is formed enclosing each of the adjacent cells. The codetected Ks filaments are retracted around the nuclei. The underlying cell-cell contact areas are also well demonstrated. It may be noted that these areas are FN-labelled. Twenty-four hr after wounding, the FN alveolar pattern persists. The redistributed Ks filaments have some similarity to those seen before wounding.

Acid helix-turn activator motif

A common sequence/structural motif pattern has been identified within the steroid/thyroid hormone receptors and other transcriptional activators using a new massively parallel symbolic learning assistant computer system. The pattern appears nearly diagnostic of transcription activation, including relative activation strength, among nuclear and DNA-binding prokaryotic proteins. In cases where mutation/deletion/chimeric studies have identified the activation domain, the pattern matches within that domain. These facts and the nature of the pattern itself strongly support the idea that the patterned domain is directly involved in a protein-protein transcription activation interaction.

Studies on the structure of HBV DNA

The structure of HBV adr NC-1 DNA is analyzed and compared with another five strains of HBV DNAs. Some of the prokaryotic promoter-like sequences, palindrom sequences and ATAA are found. An enhancer core sequence and some other characteristics are also shown. In considering the frame and its regulatory sequence as a transcriptional unit some of the possible new frames are discussed.

A prospective, controlled, double-blind, cross-over study of tripterygium wilfodii hook F in treatment of rheumatoid arthritis

A polyglycosides of Tripterygium wilfodii hook F (TWH) preparation with a code name of T2 is used in the present double-blind, controlled, cross-over study on the treatment of 70 cases of rheumatoid arthritis (RA). An impressive curative effect of T2 is confirmed much more convincingly by the present study than that by the previously reported clinical open trials. The adverse reactions and the probable pharmacological mechanism of T2 are also discussed.

Anti-fibronectin serum inhibits the disorganization of the dermal-epidermal junction in cultured wounded skin

During wound-healing in cultured frog skin fragments, fibronectin (FN) was detected in the dermal-epidermal junction. Intracellular fibronectin was stained using permeabilization and DAB immunoperoxidase. With electron microscopy intracytoplasmic FN granules were localized in the epidermal processes of the stratum germinativum cells protruding towards the dermis and in their marginal regions (membrane-associated plaques). Faint staining was visible at the level of the lamina densa and inside some parts of the lamina lucida. In comparison, contrasted ultrathin sections revealed classical disorganization of the dermal-epidermal junction. In the presence of anti-fibronectin serum during the whole time of culture, fibronectin-antifibronectin binding was visualized in the form of sparse cytoplasmic granules in the epidermal processes of the stratum germinativum cells. Contrasted ultrathin sections emphasized the continuity between the tonofilaments, the anchoring filaments and the anchoring fibrils. Briefly, anti-fibronectin serum inhibits the disorganization of the dermal-epidermal junction in cultured wounded skin.

Fibronectin network recovery in confluent PtK2 cells after acrylamide treatment

Confluent PtK2 cells 4 hr treated with 5 mM acrylamide were FN-detected by indirect immunofluorescence. The initial fibrillar-FN network was replaced by an alveolar-type network located at the cell-cell contacts areas in the form of a thick frame with a lace-like appearance. Afterwards, acrylamide removal was obtained by several washes with fresh FCS-free culture medium. Then, PtK2 cells were returned to the incubator for 20 hr. Cell recovery was indicated by reversion of the initial fibrillar-FN network. These data show that FN reversion was possible without any changes in shape and cytoplasmic organization of non-motile growing cells.

Culture media conditioned by wounded cells modify the fibronectin localization pattern of unwounded confluent PtK2 cells

A confluent PtK2 cell sheet was incised in a serum-free culture medium, at 15 min, 2 hr and 24 hr after wounding. The culture media were collected in the same way and used as conditioned media. Unwounded confluent cells were cultured in the conditioned medium for 24 hr. They showed a modification of fibronectin localization similar to that which we had previously observed in wounded confluent PtK2 cells: cells lost their normal fibronectin fibrils and were surrounded by fibronectin lace. This finding suggested that during wound healing, the cells released soluble chemical factors which could modify the fibronectin localization pattern of unwounded confluent cells. Subconfluent cells did not respond to conditioned media, showing that confluent cells and subconfluent cells had different susceptibilities.

Cultured epidermis influences the fibril organization of purified type I collagen gels

Purified type I collagen gel used as culture substrate was composed of unstriated fibrils. Before culture, gel fragments were coated with culture medium with or without fetal calf serum (FCS+ coated or FCS- coated gels). Each gel fragment was apposed to a fragment of frog skin at the medium/air interface in Trowell culture chamber. After 7 days at 20 degrees C, the coated gels were covered with newly formed epidermis containing fibronectin localized around the keratinocytes, whose morphology was considerably modified. Fibroblast-shaped keratinocytes were localized in the anterior zone of the newly formed epidermis on FCS+ gels. The long axis of the cells was parallel to the gel surface, where numerous unstriated fibrils were located. Polyhedral keratinocytes were located in the posterior zone on FCS+ gels or the anterior and posterior zones on FCS- gels with the long axis perpendicular to the gel surface. Numerous cross-striated fibrils were found under the cultured keratinocytes in the vicinity of the basal filipodia. This model is useful for the study of collagen gel reorganization by keratinocytes.

Fibronectin (FN) localizations in mitochondria-rich cells of frog epidermis

Indirect immunoperoxidase detection of fibronectin (FN) in the ventral frog epidermis showed that only one type of epidermal cell, the mitochondria-rich cells (MRC), was FN-detected. FN was found in MRC having rounded, flask-like and intermediate shapes, located at different levels of the epidermis between the stratum germinativum and the stratum corneum. These cells contained cytoplasmic FN particularly in the form of small granules. Our results support the view that MRC differ from other epidermal cells in their in vivo FN localizations.

An immunocytochemical method for the localization of fibronectin in Araldite-embedded specimens

The detection of fibronectin (FN) in osmium-fixed and Araldite-embedded frog skin fragments was studied using a modification of Baskin's procedure (Baskin et al. 1979). Following the removal of Araldite from the semi-thin sections (0.5-1.0 micron) with ethanol-NaOH solution, the sections were bleached with hydrogen peroxide. FN was detected by indirect immunoperoxidase method. For precise localization of FN, careful attention was paid to the temperature, antibody concentrations and the quality of the ethanol-NaOH solution. Our results were in agreement with those that we had obtained previously for polyethylene glycol (PEG) sections, suggesting that the present procedure is useful for the detection of FN in Araldite-embedded biological specimens.

Dermal tracts in frog skin: fibronectin pathways for cell migration

The dermis of the frog skin (Rana esculenta) displayed a remarkable organization of vertical and horizontal tracts. Vertical thick tracts connected the dermal Stratum spongiosum with the subcutaneous tissue. Horizontal thin tracts were found alongside and contiguous to them. The thick tracts were sheathed by collagen fibrils of the Stratum compactum which were vertically oriented (i.e. parallel to the axes of the tracts) according to the horizontal and orthogonal arrangement of the collagen bundles of the Stratum compactum. The thin tracts devoid of collagenous sheath were formed by clear spaces between superimposed collagen bundles of the dermal Stratum compactum. On vertical sections, the thick tracts were seen to contain fibronectin (FN), detected by indirect immunoperoxidase. Continuous vertical FN lines were centred in these tracts. On horizontal sections, a clear zone around these FN-centred lines was also sheathed by FN. The thick tracts contained flattened pigmentary cells and fibroblasts; these cells were FN-outlined. The thin tracts contained patches of FN and FN-outlined fibroblasts. In culture, in vertical thick tracts, both pigmentary cells and fibroblasts disappeared when antiserum to FN was added to the culture medium. This suggested that thick tracts were pathways allowing pigmentary cells to move upward or downward between their usual upper dermal and lower subcutaneous localizations. Fewer fibroblasts were found in the thin tracts in the presence of antiserum to FN.

Fibronectin (FN) localizations in early wound healing of cultured frog skins

The wound healing process of frog skin fragments in epibolic cultures has provided information on FN localizations during the migration of keratinocytes. Mainly two FN localizations were studied by indirect immunodetections: Epidermal localization around keratinocytes which have acquired a fibroblastic shape. Dermal localizations of the sectioned collagen of the stratum spongiosum and stratum compactum detected at the beginning of the culture. Both localizations were observed in this epibolic wound healing process during 6 hr and 24 hr in culture and showed a differential sensitivity to cycloheximide (CHX). It was worth noting that fibronectin was permanently detected in the subcutaneous tissue of non-cultured or cultured skin fragments with or without CHX.