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Misra A, Wiens D, Kassam H, Gill R, Borgia SM. A191 HCV SCREENING VIA RAPID POINT OF CARE TESTING IN PATIENTS ON OPIATE SUBSTITUTION THERAPY IN PEEL REGION, CANADA. J Can Assoc Gastroenterol 2019. [DOI: 10.1093/jcag/gwz006.190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A Misra
- McMaster University, Hamilton, ON, Canada
| | - D Wiens
- New Direction Addiction Clinic, Brampton, ON, Canada
| | - H Kassam
- Vector Health Clinics, Mississauga, ON, Canada
| | - R Gill
- Bloom Clinic, Bramalea Community Health Centre, Brampton, ON, Canada
| | - S M Borgia
- William Osler Health System, Brampton Civic Hospital, Brampton, ON, Canada
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Merkel D, Wiens D, Kämmer J. The "Dirty Liver" as a Coincidental Finding on Sonography: Sonographic Criteria for Biliary Microhamartomas of the Liver. J Ultrasound Med 2016; 35:2139-2145. [PMID: 27672233 DOI: 10.7863/ultra.15.11081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/19/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVES Biliary microhamartomas of the liver are known as symptomless, benign, microscopic biliary duct deformations. The consistently improving quality of ultrasound technology has made it possible to visualize them, which has led to difficulty in distinguishing them from neoplastic liver alterations. The purpose of this study was to evaluate the appearance of biliary microhamartomas and their behavior on contrast-enhanced sonography. METHODS We defined typical sonographic findings in biliary microhamartomas of the liver (1 main criterion and 3 secondary criteria). Nineteen patients were identified as have typical characteristics images of biliary microhamartomas as coincidental findings on liver sonography. All patients were included in a clinical follow-up program without histologic confirmation after they underwent risk assessment. Follow-up examinations were performed with B-mode sonographic examinations at 6, 12, and 18 months. In addition, in 15 patients, contrast-enhanced sonographic examinations of the liver were performed. RESULTS None of the patients had a change in the number or size of the identifiable typical liver lesions (main criterion) after a mean follow-up period ± SD of 14.4 ± 6.5 months. There were also no alterations among the aforementioned secondary criteria in any of the participants. On contrast-enhanced sonography, the lesions of all patients showed a consistent pattern, with early arterial enrichment and persistent homogeneous contrast in the late portal venous phase. CONCLUSIONS The sonographic appearance of biliary microhamartomas is characteristic and typical enough that histologic confirmation is not always necessary. Follow-up examinations to monitor any developments are usually adequate.
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Affiliation(s)
- Daniel Merkel
- Immanuel Krankenhaus, Abteilung für Innere Medizin, Rüdersdorf bei Berlin, Germany
| | - Daniel Wiens
- St Hedwig-Krankenhaus Berlin, Klinik für Innere Medizin, Berlin, Germany
| | - Jörg Kämmer
- Gesellschaft für Leben und Gesundheit Fachklinik Wolletzsee, Angermünde, Germany
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Merkel D, Brinkmann E, Kämmer JC, Köhler M, Wiens D, Derwahl KM. Comparison Between Various Color Spectra and Conventional Grayscale Imaging for Detection of Parenchymal Liver Lesions With B-Mode Sonography. J Ultrasound Med 2015; 34:1529-1534. [PMID: 26254149 DOI: 10.7863/ultra.15.14.08062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/24/2014] [Indexed: 06/04/2023]
Abstract
OBJECTIVES The electronic colorization of grayscale B-mode sonograms using various color schemes aims to enhance the adaptability and practicability of B-mode sonography in daylight conditions. The purpose of this study was to determine the diagnostic effectiveness and importance of colorized B-mode sonography. METHODS Fifty-three video sequences of sonographic examinations of the liver were digitized and subsequently colorized in 2 different color combinations (yellow-brown and blue-white). The set of 53 images consisted of 33 with isoechoic masses, 8 with obvious lesions of the liver (hypoechoic or hyperechoic), and 12 with inconspicuous reference images of the liver. The video sequences were combined in a random order and edited into half-hour video clips. RESULTS Isoechoic liver lesions were successfully detected in 58% of the yellow-brown video sequences and in 57% of the grayscale video sequences (P = .74, not significant). Fifty percent of the isoechoic liver lesions were successfully detected in the blue-white video sequences, as opposed to a 55% detection rate in the corresponding grayscale video sequences (P= .11, not significant). In 2 subgroups, significantly more liver lesions were detected with grayscale sonography compared to blue-white sonography. CONCLUSIONS Yellow-brown-colorized B-mode sonography appears to be similarly effective for detection of isoechoic parenchymal liver lesions as traditional grayscale sonography. Blue-white colorization in B-mode sonography is probably not as effective as grayscale sonography, although a statistically significant disadvantage was shown only in the subgroup of hyperechoic liver lesions.
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Affiliation(s)
- Daniel Merkel
- St Hedwig Krankenhaus Berlin, Klinik für Innere Medizin, Berlin, Germany (D.M., J.C.K., D.W., K.-M.D.); Abteilung für Gastroenterologie, St Josefs Hospital Cloppenburg, Cloppenburg, Germany (E.B.); and Medizinische Fakultät, Charité Universitätsmedizin Berlin, Berlin, Germany (M.K.).
| | - Eckard Brinkmann
- St Hedwig Krankenhaus Berlin, Klinik für Innere Medizin, Berlin, Germany (D.M., J.C.K., D.W., K.-M.D.); Abteilung für Gastroenterologie, St Josefs Hospital Cloppenburg, Cloppenburg, Germany (E.B.); and Medizinische Fakultät, Charité Universitätsmedizin Berlin, Berlin, Germany (M.K.)
| | - Joerg C Kämmer
- St Hedwig Krankenhaus Berlin, Klinik für Innere Medizin, Berlin, Germany (D.M., J.C.K., D.W., K.-M.D.); Abteilung für Gastroenterologie, St Josefs Hospital Cloppenburg, Cloppenburg, Germany (E.B.); and Medizinische Fakultät, Charité Universitätsmedizin Berlin, Berlin, Germany (M.K.)
| | - Miriam Köhler
- St Hedwig Krankenhaus Berlin, Klinik für Innere Medizin, Berlin, Germany (D.M., J.C.K., D.W., K.-M.D.); Abteilung für Gastroenterologie, St Josefs Hospital Cloppenburg, Cloppenburg, Germany (E.B.); and Medizinische Fakultät, Charité Universitätsmedizin Berlin, Berlin, Germany (M.K.)
| | - Daniel Wiens
- St Hedwig Krankenhaus Berlin, Klinik für Innere Medizin, Berlin, Germany (D.M., J.C.K., D.W., K.-M.D.); Abteilung für Gastroenterologie, St Josefs Hospital Cloppenburg, Cloppenburg, Germany (E.B.); and Medizinische Fakultät, Charité Universitätsmedizin Berlin, Berlin, Germany (M.K.)
| | - Karl-Michael Derwahl
- St Hedwig Krankenhaus Berlin, Klinik für Innere Medizin, Berlin, Germany (D.M., J.C.K., D.W., K.-M.D.); Abteilung für Gastroenterologie, St Josefs Hospital Cloppenburg, Cloppenburg, Germany (E.B.); and Medizinische Fakultät, Charité Universitätsmedizin Berlin, Berlin, Germany (M.K.)
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Merkel D, Brinkmann E, Wiens D, Derwahl KM. In situ cooling with ice water for the easier removal of self-expanding nitinol stents. Endosc Int Open 2015; 3:E51-5. [PMID: 26134772 PMCID: PMC4423297 DOI: 10.1055/s-0034-1390760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 08/26/2014] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND It is yet to be determined what effects temperature has on the properties of nitinol in order to simplify the process of removing nitinol self-expanding metal stents (SEMS). MATERIALS AND METHODS We describe the procedure for removal of SEMS in a total of 11 cases with 9 patients. A study involving cooling of nitinol stents in situ with ice water just before their removal was attempted. RESULTS All stents were removed successfully. In partially covered and in fully covered stents, the stent rigidity was noticeably reduced following cooling. Stent removal was performed by inversion, which was achieved by pulling on the stent from its distal end. No adverse events were observed during this trial. CONCLUSION The higher pliability of the stents after ice-water cooling facilitates stent removal. With this method, a mobilization of all stents by the invagination technique was achieved. The separation of the uncoated stent ends from the intestinal wall by the invagination technique, as well as the mucosal vasoconstriction resulting from the cooling, lead to an easier SEMS removal and may serve to prevent severe bleeding of the mucosal wall during this process.
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Affiliation(s)
- Daniel Merkel
- Clinic for Internal Medicine, St. Hedwig-Krankenhaus, Berlin, Germany
- Corresponding author Daniel Merkel, MD Clinic for Internal MedicineSt. Hedwig-KrankenhausGrosse Hamburger Strasse 5-1110115 BerlinGermany+49-30-23112324
| | - Eckhard Brinkmann
- Department of Gastroenterology, St. Josefs-Hospital, Cloppenburg, Germany
| | - Daniel Wiens
- Clinic for Internal Medicine, St. Hedwig-Krankenhaus, Berlin, Germany
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Merkel D, Wiens D, Derwahl KM. Endoscopic retrieval of a scalpel from the terminal ileum. Endoscopy 2013; 44 Suppl 2 UCTN:E279. [PMID: 22933254 DOI: 10.1055/s-0032-1309862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- D Merkel
- St. Hedwig-Krankenhaus, Berlin, Germany.
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Grunow R, Verbeek L, Jacob D, Holzmann T, Birkenfeld G, Wiens D, von Eichel-Streiber L, Grass G, Reischl U. Injection anthrax--a new outbreak in heroin users. Dtsch Arztebl Int 2012; 109:843-8. [PMID: 23267409 DOI: 10.3238/arztebl.2012.0843] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 10/24/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND Injection anthrax is a rare disease that affects heroin users and is caused by Bacillus anthracis. In 2012, there were four cases in Germany, one of which was fatal, as well as a small number of cases in other European countries, including Denmark, France, and the United Kingdom. Three cases among drug users occurred in Germany in 2009/2010, in the setting of a larger outbreak centered on Scotland, where there were 119 cases. CASE PRESENTATION AND CLINICAL COURSE: We present three cases of injection anthrax, two of which were treated in Regensburg and one in Berlin. One patient died of multi-organ-system failure on the day of admission to the hospital. The others were treated with antibiotics, one of them also with surgical wound debridement. The laboratory diagnosis of injection anthrax is based on the demonstration of the pathogen, generally by culture and/or by polymerase chain reaction, in material removed directly from the patient's wound. The diagnosis is additionally supported by the detection of specific antibodies. CONCLUSION Injection anthrax may be viewed either as an independent disease entity or as a special type of cutaneous anthrax with massive edema, necrotizing fasciitis in many cases, and about 30% mortality. It has appeared in recent years among heroin users in various European countries. In patients with suggestive clinical presentation and a history of heroin use, anthrax infection must be suspected early, so that the appropriate diagnostic tests can be performed without delay. Timely treatment can be life-saving. It is therefore important that physicians--and the individuals at risk--should be well-informed about this disease.
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Mertens C, Wiens D, Steveling HG, Sander A, Freier K. Maxillary sinus-floor elevation with nanoporous biphasic bone graft material for early implant placement. Clin Implant Dent Relat Res 2012; 16:365-73. [PMID: 22897709 DOI: 10.1111/j.1708-8208.2012.00484.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Insufficient bone height in the posterior maxilla is caused by bone atrophy after tooth extraction and continued pneumatization of the maxillary sinus. To allow for implant placement in this area, external sinus-floor elevations are performed. For this indication, the application of various bone graft materials can be a reliable alternative to autologous bone. PURPOSE The aim of this study was to analyze a nanoporous bone graft material under the condition of early implant treatment in sinus floor elevations. MATERIALS AND METHODS Sixty-six patients received 94 individual external sinus-floor elevations as a precondition for implant surgery. As grafting material, a synthetic, nanoporous bone graft material consisting of a mixture of nano-hydroxyapatite and nano-β-tricalciumphosphate crystals, combined with blood from the defect side, was used. Depending on the remaining vertical bone height, implant placement was performed either simultaneously with bone augmentation or consecutively in a delayed approach. After a 4-month healing period, the patients received 218 implants and were followed up clinically, radiographically, and histologically. To quantify the bone situation at implant placement, immunohistochemical analysis using tenascin-C was performed. RESULTS We achieved an average vertical bone increase of 8.28 mm (SD, 2.59) for the one-stage approach and 10.99 mm (SD, 1.73) for the two-stage approach after sinus-floor elevation. The augmented areas showed mean resorption rates of 10.32% (one stage) and 10.82% (two stages) of vertical graft during the observation period. Immunohistochemical analysis after 4 months of healing showed high tenascin activity, indicating bone growth. Good primary stability was achieved during implant placement. Mean peri-implant marginal bone loss was 0.45 mm (SD, 0.31). CONCLUSION After a mean observation time of 21.45 months, the biomaterial showed good osseointegration and bone stability radiographically. Adding to this the positive histological and immunohistochemical findings, we conclude that, after a relatively short 4-month healing period, the biomaterial showed predictable results.
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Affiliation(s)
- Christian Mertens
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
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Abstract
Viscum fischeri has 2n = 23 chromosomes in male plants. These fornm 7 bivalents and a translocation chain of 9 chromosomes during meiosis. Pollen with 11-and 12-chromosome genomes is thus produced. Female plants have 2n = 22 chromosomes and produce 11 bivalents during meiosis. Sex determination is technically a rare multiple X-multiple Y type, but more importantly it provides the mechanism whereby permanent translocation heterozygosity is maintained in the system. In a second species, Viscum engleri, male plants have 2n=28 chromosomes associating as 11 bivalents and a ring of 6 chomosomes at meiosis.
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Ising H, Babisch W, Kruppa B, Lindthammer A, Wiens D. Subjective work noise: a major risk factor in myocardial infarction. Soz Praventivmed 1997; 42:216-22. [PMID: 9297760 DOI: 10.1007/bf02298042] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The relationship between subjective work noise exposure and the risk of myocardial infarction (MI) was assessed in a population based case-control study. 395 MI patients (31-65 years) were compared to 2148 controls from a random population sample with the same agelsex distribution. The relative risk (RR) for MI-adjusted for control variables (smoking, age, social status, etc.)-was found to increase significantly and steadily with noise category. Subjective work noise exposure was the second greatest risk factor for MI after smoking. Possible bias due to overreporting of subjective noise exposure is discussed. Interdisciplinary studies on the relationship between cardiovascular diseases and work-related stressors including subjective and objective noise assessment are needed to quantify the risk of MI due to work noise.
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Affiliation(s)
- H Ising
- Institut für Wasser-, Boden- und Lufthygiene, Berlin
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Abstract
Seismic tomography revealed a low seismic velocity (-5%) and high Poisson's ratio (+6%) anomaly covering about 300 square kilometers at the hypocenter of the 17 January 1995, magnitude 7.2, Kobe earthquake in Japan. This anomaly may be due to an overpressurized, fluid-filled, fractured rock matrix that contributed to the initiation of the Kobe earthquake.
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Affiliation(s)
- D Zhao
- D. Zhao and D. Wiens, Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA. H. Kanamori, Seismological Laboratory 252-21, California Institute of Technology, Pasadena, CA 91125, USA. H. Negishi, Disaster Prevention Research Institute, Kyoto University, Uji 611, Japan
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Abstract
BACKGROUND Connexins are cell surface proteins that form specialized regions of cell-cell communication called gap junctions. These allow impulse conduction in in voluntary muscle tissue such as the heart, but also allow the formation of communities of like cells during development of organs. METHODS We used an antipeptide antibody to connexin 43 in immunolocalization studies and an anti-peptide antibody to an external loop domain common to most connexins in Western blotting of total heart protein to measure the accumulation of connexins in the heart as it develops from 33 hours to 21 days (hatching), and in the adult. RESULTS Immunolocalization revealed that connexin 43 is widely distributed in the earliest organ rudiments. It is especially prominent in the neural tube and its derivatives, in the lens and nasal placodes, in the foregut and its derivatives, in the somites, in the mesonephric tubules, and in the heart and major arteries. Heart tissue staining grew more intense with development through day 8. However, at day 11 and day 15, and in the adult, heart staining diminished. Endocardium and valve tissue did not stain. Western blotting of heart homogenates with the antibody directed against the external loop domain peptide showed 26, 32, 43, 45, and 56 kilodalton connexins, which changed in relative abundance, displaying unique patterns during development. CONCLUSIONS Our results show patterns of connexin immunolocalization in early germ layers and organ rudiments that are similar to those known in the mouse, but with certain differences. Our results show a distinctive pattern of multiple connexin gene expression in the developing heart from days 2-21.
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Affiliation(s)
- D Wiens
- Department of Biology, University of Northern Iowa, Cedar Falls 50614, USA
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Hannah KJ, Conley-Price P, Fenty D, McKiel E, Soltes D, Hogan T, Wiens D. Computer applications for staff development and patient education. Methods Inf Med 1989; 28:261-6. [PMID: 2695778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The changing and evolving profession of nursing necessitates extensive staff development activities on the part of nursing management. This ongoing responsibility is essential to maintaining the currency and competence of practicing nurses and facilitating their professional growth. Simultaneously there are economic constraints coinciding with increased consumer demands for patient education. The purpose of this paper is to explore an innovative teaching method, the use of instructional computing for staff development and patient education programs. The theoretical frameworks for this instructional modality are identified and general advantages and disadvantages of instructional computing applications are described. Specific examples of programs from the literature are briefly discussed.
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Hawksworth FG, Wiens D. Two new species, nomenclatural changes, and range extensions in Mexican Arceuthobium (Viscaceae). ACTA ACUST UNITED AC 1989. [DOI: 10.5962/bhl.part.9801] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Wiens D, Park CS, Stockdale FE. Milk protein expression and ductal morphogenesis in the mammary gland in vitro: hormone-dependent and -independent phases of adipocyte-mammary epithelial cell interaction. Dev Biol 1987; 120:245-58. [PMID: 3817293 DOI: 10.1016/0012-1606(87)90122-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Epithelial cell differentiation frequently occurs in situ in conjunction with supporting mesenchyme or connective tissue. In embryonic development the importance of the supporting mesenchyme for cytodifferentiation and morphogenesis has been demonstrated in several epithelial tissues, but the importance of epithelial-connective tissue interactions is less well studied in adult epithelial organs. We have investigated the interaction of adult mammary epithelial cells with adipocytes, which compose the normal supporting connective tissue in the mammary gland. Mammary epithelial cells from mice in various physiological states were cultured on cellular substrates of adipocytes formed from cells of the 3T3-L1 preadipocyte cell line. We found that there were two distinct phases to the interaction of epithelial cells with adipocytes. Cytodifferentiation of the epithelial cells and milk protein production were dependent on lactogenic hormones (insulin, hydrocortisone, and prolactin), whereas ductal morphogenesis was lactogenic hormone independent. When cultured on preadipocytes or adipocytes, mammary epithelial cells from never pregnant, pregnant, lactating, and involuting mice responded to lactogenic hormones rapidly by producing and secreting large amounts of alpha-, beta-, and gamma-casein and alpha-lactalbumin. This response was seen in individual as well as in clusters of epithelial cells, but was not seen if the same cells were cultured on tissue culture dishes without adipocytes, on fibroblasts (human newborn foreskin fibroblasts) or in the presence of adipocytes but in the absence of lactogenic hormones. Continued incubation of mammary epithelial cells on adipocytes in the presence or absence of lactogenic hormones resulted in the formation of a branching ductal system. Mammary epithelial cells in ducts that formed in the absence of lactogenic hormones produced no casein, but rapidly synthesized casein when subsequently exposed to these hormones. Ultrastructural studies revealed that the formation of a basement membrane occurs only in co-cultures of mammary epithelium with adipocytes or preadipocytes. Ultrastructural changes associated with secretion occurred only in the presence of lactogenic hormones. We propose that growth and formation of a ductal system in vitro can occur in the absence of lactogenic hormones, but that certain environment-associated events must occur if the epithelium is to become responsive to lactogenic hormones and undergo the cytodifferentiation associated with lactation.
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Wiens D, Sullins M, Spooner BS. Precardiac mesoderm differentiation in vitro. Actin-isotype synthetic transitions, myofibrillogenesis, initiation of heartbeat, and the possible involvement of collagen. Differentiation 1984; 28:62-72. [PMID: 6519368 DOI: 10.1111/j.1432-0436.1984.tb00267.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The differentiation of precardiac mesoderm into beating heart tissue was examined during explant culture. Explanted tissue forms tubular heart-like vesicles and initiates rhythmic contractility within 18-24 h in vitro, a developmental time-course approximating that observed during in vivo development. Electron-microscopic observations reveal that beating heart cells are rich in cytoplasmic myofibrils in varying degrees of order, with some regions containing highly organized myofibrillar arrays. The analysis of actin-isotype biosynthesis, using metabolic labeling with [35S]-methionine and isoelectric-focusing resolution of the synthesized radioactive polypeptides, demonstrates that the initiation of cardiac alpha-actin synthesis and the pattern of transition in the synthesis of alpha-, beta-, and gamma-actin isotypes is equivalent to the initiation time and pattern observed in vivo. A possible collagen involvement in the differentiation process was investigated by assessing the effects of collagen-synthesis inhibitors on the development of the explant cultures. Two different agents, alpha, alpha'-dipyridyl and L-azetidine-2-carboxylic acid, exhibited a dose-dependent ability to inhibit the formation of beating heart tissue. When examined by electron microscopy, the nonbeating tissue exhibited a drastic depression of myofibrillogenesis, but otherwise appeared healthy. Further examination of the effect of L-azetidine-2-carboxylic acid demonstrated that the inhibition of myofibril formation and heartbeat was correlated with a 60% inhibition of native collagen synthesis; however, the time-course and pattern of actin-isotype biosynthesis was completely unaffected. The data suggest a possible involvement in heart differentiation that is necessary for either the synthesis of non-actin cardiac contractile proteins or the assembly of cardiac contractile proteins into myofibrils.
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Wiens D, Spooner BS. Actin isotype biosynthetic transitions in early cardiac organogenesis. Eur J Cell Biol 1983; 30:60-6. [PMID: 6852062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Barlow BA, Wiens D, Wiens C, Busby WH, Brighton C. Permanent translocation heterozygosity in Viscum Album and V. Cruciatum: sex association, balanced lethals, sex ratios. Heredity (Edinb) 1978. [DOI: 10.1038/hdy.1978.4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Wiens D, Barlow BA. Unusual translocation heterozygosity in an East African mistletoe (Viscum fischeri). Nat New Biol 1973; 243:93-4. [PMID: 4512965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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