Identification of a pathogenicity island required for Salmonella survival in host cells.

We have identified a region unique to the Salmonella typhimurium chromosome that is essential for virulence in mice. This region harbors at least three genes: two (spiA and spiB) encode products that are similar to proteins found in type III secretion systems, and a third (spiR) encodes a putative regulator. A strain with a mutation in spiA was unable to survive within macrophages but displayed wild-type levels of epithelial cell invasion. The culture supernatants of the spi mutants lacked a modified form of flagellin, which was present in the supernatant of the wild-type strain. This suggests that the Spi secretory apparatus exports a protease, or a protein that can alter the activity of a secreted protease. The "pathogenicity island" harboring the spi genes may encode the virulence determinants that set Salmonella apart from other enteric pathogens.     

Ultrasound Densitometric Analysis: Comparison Between an Online Digital Acquisition Acoustic Program and an Offline Analog Program

Videodensitometric analysis of myocardial contrast echocardiography is traditionally performed off line. Recently, an online contrast ultrasound analysis system, Acoustic Densitometry (Hewlett-Packard), was introduced. We compared pixel intensities acquired with Acoustic Densitometry to pixel intensities derived from videodensitometry. A tissue phantom was imaged in phase I using three transducer frequencies (2.5, 3.5, and 5.0 MHz). In phase II, an in vitro flowing tube model with various concentrations of Albunex® was imaged at two flow rates, 0.6 and 1.2 m/sec, and at two transducer frequencies, 2.5 and 3.5 MHz. The relationship between pixel intensities yielded by the two systems for identical ultrasound signals was determined with linear regression. Intensities derived with Acoustic Densitometry strongly correlated with those derived from the offline videodensitometry system. The intensities were related by a predictive multiplicative factor based on display characteristics of the two systems. These results suggest that semiquantitative, online perfusion analysis with Acoustic Densitometry is as sensitive as analysis offline with videodensitometry.     

Unintentional intraoperative awareness during sufentanil anaesthesia for cardiac surgery

Purpose

The aim of this clinical report is to describe a case of unintentional intraoperative awareness during sufentanil anaesthesia in a patient undergoing elective aortocoronary bypass grafting.

Clinical findings

After premedication with morphine (5 mg) and scopolamine (0.2 mg), this 51-yr-old woman received sufentanil (10 μg · kg^?1), midazolam (4 mg) and isoflurane (0.3–0.4% end-tidal). The patient recalled specific events and discussions which took place in the operating room during surgery. This patient’s report was clear and corroborated by operating room personnel. The patient denied having felt pain, anxiety or emotional distress.

Conclusion

Although awareness during opioid anaesthesia has been previously described with morphine and fentanyl, as far as we know this is the first clinical report of awareness with sufentanil. Given that recent efforts of early extubation in cardiac surgery patients may involve a reduction in the amount of opioid administered, this report serves as a reminder of the ever present potential for this disturbing complication.     

Duodenal ulcer and working-class mobility in an African population in South Africa

The number of Africans in Johannesburg presenting with duodenal ulcers has steadily increased over the past 50 years. The characteristics of 105 patients with duodenal ulcer who presented a Baragwanath Hospital were compared with those of matched and unmatched samples of patients without gastrointestinal conditions in the same hospital. Men with duodenal ulcers were found to be significantly better educated than their controls, most had been born in the town, and more of them were employed at higher, though not the highest, educational levels. These data were used to test Susser's proposition that duodenal ulcers are associated with "early urbanisation." Johannesburg blacks with duodenal ulcer did seem to fit the pattern, but the relation between stress and duodenal ulcer remains unclear.     

Cyclic nucleotide phosphodiesterase. Insulin activation detected in adipose tissue by gel electrophoresis.

In rat adipose tissue, insulin (100 muU./ml.) increases the activity of cyclic AMP (but not cyclic GMP) phosphodiesterase (PDE). Radioisotopic assay, autoradiography, and histochemical stains demonstrated that cyclic nucleotide PDE activity is associated with multiple bands of protein separable by polyacrylamide gel electrophoresis. The insulin activation of cyclic AMP PDE, however, was limited to a single band corresponding to the "low" Km enzyme specific for cyclic AMP; insulin had no effect on the "high" Km enzyme or on PDE bands with activity directed toward cyclic GMP. These data support the concept that insulin may modulate the activity of at least one of the cyclic AMP phosphodiesterases.