Integration of viral into chromosomal deoxyribonucleic acid in an inducible line of polyoma-transformed cells

RNA-DNA hybridization has shown that in poiyoma-transformed rat cells which can be induced to synthesize infectious virus (LPT cells), polyoma DNA sequences are associated with chromosomal DNARNA complementary to the viral DNA (cRNA) was synthesized in vitro, using purified viral DNA as a template and Escherichia coli RNA polymerase. High-molecular-weight chromosomal DNA was fractionated from linear and supercoiled viral DNA molecules by centrifugation of whole cells through alkaline glycerol gradients. Hybridization carried out between the cRNA and fractionated chromosomal DNA showed that the amount of RNA hybridized to the LPT DNA was two to three times larger than the amount hybridized to DNA from normal rat cells. cRNA was also hybridized, under the same conditions, with mixtures containing a constant amount of normal cell DNA and varying quantities of purified viral DNA. These assays have established that a linear relationship exists between the amount of cRNA specifically hybridized with a given sample of DNA and the quantity of viral DNA in the sample. Using this relationship, it is estimated that LPT chromosomal DNA contains 6–9 genome-equivalents of polyoma DNA per cell. This quantity represents 18–29% of the amount of polyoma DNA found in the cells, as determined by hybridization of cRNA with unfractionated LPT DNA.To exclude the possibility that the chromosomally associated viral DNA is an artifact due to incomplete removal of the extrachromosomal viral DNA, control experiments were performed in which the cells were superinfected with polyoma virus (m.o.i.-500; 3 hr infection). In these experiments, less than 1% of the viral DNA introduced into the cells by the superinfecting virus were found by the same techniques to be associated with chromosomal DNA. Other experiments show that LPT cells do not contain significant amounts of complex viral DNA molecules which sediment in the vicinity of chromosomal DNA. It is therefore suggested that viral and chromosomal DNA are bound to each other by bonds which cannot be disrupted by alkali treatment.     

Enteroenterale Invagination des Dünndarms beim Erwachsenen

Zusammenfassung Es wird über eine 43jährige Patientin berichtet, die mehrere Wochen lang über inkonstant auftretende, krampfartige Mittelbauchschmerzen klagte. Die Diagnose einer ileoilealen Invagination konnte bei der Patientin erst beim dritten stationären Aufenthalt gestellt werden. Folgende Fehldiagnosen waren während des 4wöchigen Verlaufs bei der Patientin gestellt worden: Nierenbeckenentzundung, acute Appendizitis, chronische Appendizitis und zuletzt psychosomatische Bauchschmerzen. Die Patientin wurde zunächst antibiotisch, zuletzt mit Psychopharmaka medikamentös behandelt. Schließlich wurde die Diagnose einer Invagination des Dünndarms mittels Sonographie vermutet und in der konventionellen fortlaufenden Magen-Darm-Passage röntgenologisch gesichert. Bei der Patientin wurde daraufhin eine Dünndarmsegmentresektion durchgeführt. Die enteroenterale Invagination ist im Erwachsenenalter ein sehr seltenes Ereignis, bei der meistens eine Ursache (oft Tumore) als Auslöser der Invagination ermittelt werden kann. Durch Peristaltik und Ingesta wird der nach aboral bewegte Tumor zum Motor der Invagination. Prädilektionsorte sind die Übergänge eines beweglichen zu einem retroperitoneal fixierten Darmabschnitts (z. B. Ileozökalregion). Die Sonographie des Abdomens ist die Methode der ersten Wahl bei der Diagnose einer enteroenteralen Invagination. Beim Erwachsenen ist die operative Beseitigung der Invagination und deren Ursache (meist Tumore) angezeigt.

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Entero-enteric invagination of the small intestine in adultsA rare cause of abdominal distress

The present paper reports on a 43-year-old female patient who complained over a number of weeks of paroxysms of crampy pain in the mesogastrium. The diagnosis of ileoileal invagination was only made after she had been admitted to hospital for the third time. The following false diagnoses had been made during the 4-week course of the condition: pyelonephritis, acute appendicitis, chronic appendicitis and, most recently psychosomatic abdominal distress. The patient was initially treated with antibiotics and finally with psychotropic drugs. Eventually ultrasound suggested the diagnosis of invagination of the small intestine, which was then verified by conventional barium follow-through radiography. The patient subsequently underwent resection of a segment of the small intestine. Entero-enteric invagination is a very rare event in adults, in which a single (often malignant) cause is identified as triggering the invagination. Peristalsis and ingested food push the tumor distad, thus acting as a motor for invagination. The preferred localizations are the junctions between freely moving segments to retroperitoneally fixed segments (e.g., ileocecal region). Ultrasound of the abdomen is the examination of choice for diagnosis of enteroenteric invagination. Surgical resection of the invagination and its cause (generally tumors) is indicated in adults.

     

Adenocarcinoma arising in Barrett's esophagus

A review of nine adenocarcinomas of the esophagus arising in Barrett's epithelium was undertaken. We found the disease among white males disproportionately. Risk factors and incidence rate remain to be clarified. Only one patient was in a surveillance program and only he had carcinoma discovered "early." He still survives while only one of the eight whose diagnosis followed investigation of symptoms remains alive.     

Long-term discordant xenogeneic (porcine-to-primate) bone marrow engraftment in a monkey treated with porcine-specific growth factors

BACKGROUND: Mixed allogeneic hematopoietic chimerism has previously been reliably achieved and shown to induce tolerance to fully MHC-mismatched allografts in mice and monkeys. However, the establishment of hematopoietic chimerism has been difficult to achieve in the discordant pig-to-primate xenogeneic model. METHODS: To address this issue, two cynomolgus monkeys were conditioned by whole body irradiation (total dose 300 cGy) 6 and 5 days before the infusion of pig bone marrow (BM). Monkey anti-pig natural antibodies were immunoadsorbed by extracorporeal perfusion of monkey blood through a pig liver, immediately before the intravenous infusion of porcine BM (day 0). Cyclosporine was administered for 4 weeks and 15-deoxyspergualin for 2 weeks. One monkey received recombinant pig cytokines (stem cell factor and interleukin 3) for 2 weeks, whereas the other received only saline as a control. RESULTS: Both monkeys recovered from pancytopenia within 4 weeks of whole body irradiation. Anti-pig IgM and IgG antibodies were successfully depleted by the liver perfusion but returned to pretreatment levels within 12-14 days. Methylcellulose colony assays at days 180 and 300 revealed that about 2% of the myeloid progenitors in the BM of the cytokine-treated recipient were of pig origin, whereas no chimerism was detected in the BM of the untreated control monkey at similar times. The chimeric animal was less responsive by mixed lymphocyte reaction to pig-specific stimulators than the control monkey and significantly hyporesponsive when compared with a monkey that had rejected a porcine kidney transplant. CONCLUSION: To our knowledge, this is the first report of long-term survival of discordant xenogeneic BM in a primate recipient.