[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.

[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 (ß=-40.182, 95%CI:-69.847--10.517), ODI (ß=3.539, 95%CI: 0.600-6.478) were the risk factors of PRM immediate reaction time. Age(ß=13.303,95%CI: 2.487-24.119), years of education(ß=-32.329, 95%CI:-63.162--1.497), ODI (ß=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 (ß=1.258, 95%CI: 0.379-2.137). TS90 was the risk factor of MOT reaction time (ß=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.

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 enhanced linear-splinter amplification sequencing, a previously described cell-free DNA (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 1693 participants (cancer: n = 735; non-cancer: n = 958) were retrospectively collected to train and validate two multi-cancer detection blood test (MCDBT-1/2) models for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1010 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 a 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 high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.

[Mutation of dentin sialophosphoprotein and hereditary malformations of dentin].

The classification as well as the clinical manifestations of hereditary malformations of dentin are of great concern and have been deeply elucidated. The understanding of its genetic basis also increases progressively. Dentin sialophosphoprotein (DSPP) is the pathogenic gene of dentinogenesis imperfecta type Ⅱ, dentinogenesis imperfecta type Ⅲ and dentin dysplasia type Ⅱ. In this article, the classification of DSPP mutations as well as the resultant dysfunction of the mutant DSPP are summarized respectively and the corresponding clinical manifestations are analyzed. This work will provide a reference for the diagnosis and treatment of hereditary malformations of dentin.

[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 (ß=-2.812, P=0.049), alveolar bone height (ß=1.521, P=0.020), donor time (ß=-2.001, P=0.019), use of donor model (ß=1.666, P=0.034) and initial stability (ß=-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.

MiR-187 influences cisplatin-resistance of gastric cancer cells through regulating the TGF-ß/Smad signaling pathway.

OBJECTIVE: To explore the effect of micro-ribonucleic acid (miR)-187 on cisplatin (DDP) resistance of gastric cancer cells by regulating the transforming growth factor-ß (TGF-ß)/Smad signaling pathway. MATERIALS AND METHODS: DDP-sensitivities in GES-1, SGC7901, and SGC7901/DDP cells were detected via Cell Counting Kit-8 (CCK-8) assay. The differential expression of miR-187 of these cell lines was detected by Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR). DDP-resistant gastric cancer cells SGC7901/DDP were divided into control group (blank control), miR-187 inhibitor group (SGC7901/DDP cells transfected with miR-187 inhibitor), and miR-187 mimic group (SGC7901/DDP cells transfected with miR-187 mimic). The protein expressions of miR-187, TGF-ß1, p-Smad4, excision repair cross-complementation group 3 (ERCC3), and ERCC4 were determined through RT-qPCR, immunohistochemistry, and Western blotting. The apoptosis in each group was detected by flow cytometry. RESULTS: MiR-187 level had a negative correlation with DDP-resistance of GES-1, SGC7901, and SGC7901/DDP cells, and among them, the GES-1 cells had the lowest DDP-resistance and the highest expression of miR-187. CCK-8 assay revealed that compared with that in the control group, DDP-resistance significantly declined in the miR-187 mimic group, while it was significantly enhanced in miR-187 inhibitor group (p<0.01). According to the results of flow cytometry, after treatment with 100 nM DDP for 12 h, the apoptotic rate in miR-187 mimic group enhanced, while it was markedly reduced in the miR-187 inhibitor group (p<0.01). Western blotting and immunohistochemistry results showed that expressions of TGF-ß1 and p-Smad4 were significantly downregulated in the miR-187 mimic group, while they were upregulated in the miR-187 inhibitor group (p<0.01). Besides, compared with the control group, ERCC3 and ERCC4 were downregulated in the miR-187 mimic group, while upregulated in miR-187 inhibitor group (p<0.01). CONCLUSIONS: The overexpression of miR-187 alleviates DDP-resistance in gastric cancer cells by inhibiting the TGF-ß/Smad signaling pathway.

MiR-652-3p promotes bladder cancer migration and invasion by targeting KCNN3.

OBJECTIVE: Increasing evidence indicated that microRNAs (miRNAs) are crucial regulators for cancer development. Bladder cancer (BCa) is a major threat to human health. The aim of this study was to analyze the roles of miR-652-3p in BCa, and to explore the associated mechanisms. MATERIALS AND METHODS: MiR-652-3p expression in BCa cell lines was explored using Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) method. MiR-652-3p expression level in BCa tissues was explored at StarBase. Cell Counting Kit-8 (CCK-8) assay, wound-healing assay, and transwell invasion assay were conducted to investigate the biological roles of miR-652-3p. The underlying mechanisms of miR-652-3p in NSCLC were investigated using luciferase activity reporter assay and rescue experiments. RESULTS: We showed that miR-652-3p expression level was upregulated in both BCa tissues and cell lines. The knockdown of miR-652-3p significantly inhibited BCa cell proliferation, migration, and invasion in vitro. Moreover, we showed that potassium intermediate/small conductance calcium-activated channel, subfamily N, member 3 (KCNN3) was a functional target for miR-652-3p. Besides, the expression of KCNN3 in BCa tissues was negatively correlated with miR-652-3p. CONCLUSIONS: Collectively, these results showed that miR-652-3p could promote BCa cell proliferation, migration, and invasion via directly regulating KCNN3, which may provide a novel therapeutic target for BCa treatment.

Removal of epicardial adipose tissue after myocardial infarction improves cardiac function.

BACKGROUND: The aim of this study was to assess the role of lipolysis of epicardial adipose tissue (EAT) in cardiac function after myocardial infarction (MI). METHODS: We used a rat model of MI with or without EAT removal to study the effects of EAT lipolysis on cardiovascular function. Echocardiography and cardiac catheterization were used to determine cardiac function, and infarct size and histopathology specimens were analyzed in postmortem sections. Inflammatory responses were evaluated via flow cytometry and Elisa analyses. RESULTS: We found that the lipolysis of EAT increased significantly after MI. Removal of the EAT after MI (MI-EAT) improved cardiac function by nearly 10% and decreased the infarct area by 6% when compared with rats retaining EAT after MI (MI+EAT). Furthermore, the removal of EAT reduced the number of CD45-positive leukocytes (50 vs. 34.8%) and increased the ratio of macrophage/leukocytes (56 vs. 75%) in the infarcted heart. Compared with the MI+EAT group, the concentration of tumor necrosis factor-alpha and interleukin 1­beta were reduced in the MI-EAT group. CONCLUSION: Lipolysis of EAT increased significantly after MI. Removal of EAT improved cardiac function, in part, by weakening the inflammatory response.

Rutin prevents the ovariectomy-induced osteoporosis in rats.

OBJECTIVE: Our study aimed to explore the anti-osteoporotic effect of rutin (quercetin-3-O-rutinose) on ovariectomized female rats. MATERIALS AND METHODS: An ovariectomized (OVX) rat model of osteoporosis was employed to evaluate the anti-osteoporotic potency of rutin. One week after surgery, the rats were administered intragastrically with rutin or saline once daily respectively for 3 months. Bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry (DEXA). The bone microstructure was analyzed by hematoxylin and eosin (HE) staining of the left tibia histomorphology. Estradiol, IL-6, and TNF-α were measured by ELISA kits. RESULTS: The results showed that rutin significantly improved the bone mineral density (BMD) and increased the level of inflammatory factor of IL-6, TNF-α, and INF-γ in OVX rats. Rutin turned bone trabecula to be thickened and dense, and kept regular array. Moreover, rutin significantly improved the average thickness of trabecular bone and the average bone volume fraction. CONCLUSIONS: Rutin possessed with significant anti-osteoporotic activity, which can be considered as an idealistic anti-osteoporotic candidate for human osteoporosis diseases.

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.

Characterisation of breast papillary neoplasm on automated breast ultrasound.

Intraductal papillary neoplasms of the breast form a wide spectrum of pathological changes with benign intraductal papilloma and papillary carcinoma. They can occur anywhere within the breast ductal system. This review illustrates some characteristic appearances of breast papillary neoplasms on coronal planes reconstructed by automatic breast volume scan. Such manifestations are not uncommon in papillary neoplasms, and familiarity will enable confident diagnosis.

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.

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.

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.

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.

Wheat germ agglutinin (WGA) reduces ADH-induced water flow and induces cell surface changes in epithelial cells of frog urinary bladder.

The functional and structural changes induced by apical wheat germ agglutinin (WGA) 100 micrograms/ml exposure on frog urinary bladder have been investigated and the possible correlations between these effects discussed. Bladders, apically exposed to WGA for 30 min to 3 hr exhibit a marked reduction of their response to antidiuretic hormone (ADH) challenge and of their hydrosmotic reactivity. Structural changes triggered by WGA treatment are: 1. apical invaginations of the plasma membrane, interpreted as endocytotic in nature, taking into account the results of carbohydrate cytochemical detection and horseradish peroxidase (HRP) exposure: 2. cytoskeleton disorganization and microvilli collapse. These phenomena do not interfere with cortical granule traffic and are independent of ADH challenge: they occur in ADH-stimulated bladders as well as in bladders at rest. These findings could be interpreted as follows: binding of the divalent lectin WGA to its coat specific receptors would induce changes in the apical membrane structure which in turn could provoke disorganization and disruption of apical cytoskeletal elements associated with plasma membrane. Reduction of bladder response to ADH challenge could result from a reduced recycling of aggrephores, as they are associated with cytoskeletal elements in the subapical cytoplasm. Collapse of microvilli and endocytotic events also could result from apical cytoskeleton disruption, as microvilli are sustained by bundles of actin filaments interconnected with apical cytoskeletal filaments and as plasma membrane is associated with apical cytoskeleton. However, these two last events evidently occur in ADH-challenged or non-challenged bladders.