Generation of a detailed physical and genetic map of the ilv-metE-udp region of the Escherichia coli chromosome.

The entire ilv-metE-udp region of the Escherichia coli chromosome has been cloned in two steps using the lambda replacement vector EMBL4. A detailed restriction map for approximately 70 X 10(3) bases of DNA has been generated. The gpp and udp structural genes have been identified, the cya and metE genes have been physically located, and the direction of recQ gene transcription has been determined.

Structural inhibition and reactivation of Escherichia coli septation by elements of the SOS and TER pathways.

The inhibition of cell division caused by induction of the SOS pathway in Escherichia coli structurally blocks septation, as deduced from two sets of results. Potential septation sites active at the time of SOS induction became inactivated, while those initiated during the following doubling time were active. Penicillin resistance increased in wild-type UV light-irradiated cells, a behavior similar to that observed in mutants in which structural blocks were introduced by inactivation of FtsA.

Interaction of FtsA and PBP3 proteins in the Escherichia coli septum.

Mutations in the ftsA gene of Escherichia coli conferred a higher resistance to lysis induced by penicillin or by a combination of cefsulodin and furazlocillin. The ftsA2 allele codes for an FtsA protein which is inactive at 42 degrees C but is able to regain its activity once it is transferred back to 30 degrees C; ftsA2 filaments formed at 42 degrees C in the presence of penicillin divided once the penicillin was removed and the temperature was lowered to 30 degrees C. Potential septation sites in the filaments of wild-type cells treated in the same way remained inactive.

Coupling between DNA replication and cell division mediated by the FtsA protein in Escherichia coli: a pathway independent of the SOS response, the "TER" pathway.

Inhibition of DNA synthesis prevented the recovery of cell division in filaments of D-3R [ftsA3(Ts) recA56] returned to the permissive temperature. The FtsA protein may be a signal involved in the "TER" pathway, a series of events that coordinate cell division with DNA replication, that is independent of the SOS pathway.

Cell length in a wee dnaA mutant of Escherichia coli.

The cell length of the short siblings of dividing pairs formed in the absence of replication by two strains of Escherichia coli, OV-25-9 [dnaA46 wee(Am)] and OV-25-10 [dnaA46 wee(AM) supF] was measured. In the presence of Wee, the length of these cells increased to those values expected for newborn wild-type cells growing under similar conditions. In its absence, cell length remained at values near the minimum unit length possible for newborn cells.

[Clinical and therapeutic aspects in perforated gastroduodenal ulcer].

A total of 591 cases were studied, with perforated gastroduodenal ulcerations, who underwent surgery in the Emergency Clinic of Bucharest in 1978-1979. Of the 591 patients 528 had duodenal perforations, 58 had gastric perforated ulcers, 4 had perforated duodenal ulcers and gastric ulcers penetrating in the pancreas, and one patient had a peptic perforated ulcer. Several factors are studied in this paper, including: age, the interval from the onset of the symptoms to hospitalization, the duration of preoperative preparations, the anatomo-clinical forms of the perforated gastro-duodenal ulcers, the type of surgical treatment, the evolution and the complications after surgery.

Surface density of major outer membrane proteins in Salmonella typhimurium in different growth conditions.

The amount of major proteins per unit of surface area in the outer membrane (OM) of Salmonella typhimurium LT2 remained constant during steady-state growth in different media. Between growth rates of 2.40 doublings h-1 and 0.