A PAS domain within F plasmid TraJ is critical for its function as a transcriptional activator.

TraJ is the positive activator of the major transfer operon in the F plasmid of Escherichia coli that counteracts H-NS silencing at the main transfer promoter (P(Y)). Multiple sequence alignment revealed a putative PAS (Per-ARNT-Sim) domain that might be involved in sensing redox potential or energy levels in the cell. This domain, which contains a conserved PXCXR motif along with a C(X)(9-10)CR/N/K motif of variable position, was identified within the N-terminal region of TraJ orthologues including F TraJ. The 5 cysteine residues in F TraJ were changed to serine to give protein with single or multiple substitutions. Single C to S substitutions had little effect on mating efficiency (ME), whereas cumulative substitutions from the N- to the C-termini (2CS to 5CS) gradually reduced ME to undetectable levels. F TraJ was able to bind to Fe (III) on an affinity sorbent column. This feature was severely impaired for the 5CS mutant. Thus, the cysteine residues within the PAS domain could be the part of a metal-containing redox centre that plays a key role in the transcriptional activation of the P(Y) operon by TraJ.

Fatal Apophysomyces elegans infection transmitted by deceased donor renal allografts.

Two patients developed renal mucormycosis following transplantation of kidneys from the same donor, a near-drowning victim in a motor vehicle crash. Genotypically, indistinguishable strains of Apophysomyces elegans were recovered from both recipients. We investigated the source of the infection including review of medical records, environmental sampling at possible locations of contamination and query for additional cases at other centers. Histopathology of the explanted kidneys revealed extensive vascular invasion by aseptate, fungal hyphae with relative sparing of the renal capsules suggesting a vascular route of contamination. Disseminated infection in the donor could not be definitively established. A. elegans was not recovered from the same lots of reagents used for organ recovery or environmental samples and no other organ transplant-related cases were identified. This investigation suggests either isolated contamination of the organs during recovery or undiagnosed disseminated donor infection following a near-drowning event. Although no changes to current organ recovery or transplant procedures are recommended, public health officials and transplant physicians should consider the possibility of mucormycosis transmitted via organs in the future, particularly for near-drowning events. Attention to aseptic technique during organ recovery and processing is re-emphasized.

[Angioplasty of the proximal left anterior descending artery outside the acute phase of myocardial infarction. Apropos of a series of 100 consecutive patients]. / Angioplastie de l'artère interventriculaire antérieure proximale en dehors de la phase aiguë de l'infarctus du myocarde. A propos d'une série consécutive de 100 patients.

The indications of percutaneous transluminal coronary angioplasty (PTCA) of the proximal left anterior descending artery (LAD 1) must take into consideration the importance of the threatened myocardial territory in case of complications and the supposedly increased risk of restenosis of this arterial segment. One hundred consecutive patients (average age 59.9 +/- 11.4 years with 77% of men) outside the acute phase of myocardial infarction were included in this retrospective open study from January 1st 1988 to March 1st 1992. There were 76 cases of single vessel. The average left ventricular ejection fraction was 64.8 +/- 12%. During the hospital period, there were no deaths. 1 myocardial infarction despite emergency coronary bypass surgery, and 2 programmed coronary bypass procedures. During follow-up, "clinical restenosis" as defined by the authors was observed in 29.7% of cases; 1 patient died of cardiovascular causes, 18 had a repeat PTCA with a success rate of 100%. The clinical restenosis rate of repeat PTCA was 33%. One patient underwent a third PTCA with a successful outcome. Ten coronary bypass procedures were necessary. Restenosis was more common after PTCA of lesions situated on a bifurcation and when high inflation pressures had to be used. Restenosis was constant after repeat PTCA when the initial restenosis occurred before the 60th day.

Molecular epidemiology of norovirus gastroenteritis outbreaks in North Carolina, United States: 1995-2000.

Noroviruses (NoVs) are the most common cause of acute non-bacterial gastroenteritis outbreaks in the US. We investigated 16 gastroenteritis outbreaks in North Carolina (NC), from 1995 to 2000, to further characterize the epidemiology of NoV using RT-PCR on stool and ELISA on sera. NoV were identified in 14 outbreaks by RT-PCR. Sequence analyses of the amplicons indicated the outbreak strains belonged to the following clusters: five GII/4, three GI/3, one GI/4, one GII/2, one GII/5, one GII/7, and one GII/13 (prototype strain). We detected NoV in stool samples from one outbreak but could not determine its specific cluster within the GII genogroup based on polymerase sequence analysis. The five GII/4 strains were classified as the "95/96 US common strain" and occurred throughout the 5-year period. In contrast to national trends, the majority (86%) of NoV outbreaks identified in North Carolina were foodborne. Of the 12 food-related NoV outbreaks, we were able to document transmission by food handlers in two outbreaks. Person-to-person transmission from primary cases was suggested in three outbreaks. Our results indicate that NoVs are important agents of viral gastroenteritis outbreaks in NC.

[Silicosis and bronchial cancer (author's transl)]. / Silicose et cancer bronchique.

1. At world level, silicosis does not predispose to bronchial cancer. But from region to region, the relationship silicosis-cancer varies and depends on factors other than silica. 2. It has not been proved that silica is cancerigen in laboratory animal. 3. Subjects exposed to silica can also be exposed in other circumstances to known carcerigen agents (ionizing radiations, iron oxides, arsenic, exhaust gases of explosion engins). In Switzerland, it is possible that miners in galeries could breath low concentrations of radon and benzopyrene. But it is very difficult to know to what extent these potential risks are involved. 4. Bronchial carcinoma in silicotic patients does not own any characteristics. It is quite similar to that found in the remainder of the population. On the other hand, its diagnosis and treatment are more difficult because of the presence of silicosis. 5. The fortuitous association of silicosis and bronchial cancer is due to overlapping of the profiles of both diseases. The increasing life span of the silicotic patient and the high frequency of bronchial cancer explain why this association is not more exceptional.

[Silicosis in Switzerland. A half century of observation. The physician's viewpoint]. / La silicose en Suisse. Un demi-siècle d'observation. Le point de vue du médecin.

In Switzerland, the first cases of silicosis were recorded by Zangger in 1900. Since 1930, patients with silicosis have been provided with certain services by the "Caisse Nationale Suisse d'Assurances" (i.e. Swiss National Insurance Fund), an organization enforcing the Occupational Accidents and Diseases Bill. However, it took another two years before an effectively organized struggle against silicosis was started. Eventually, by 1938, this specific pneumoconiosis was acknowledged as an occupational disease under Swiss Law. Thus, the CNSA has been concerned with this disease for half a century, and it seems relevant now to take stock of the situation. From 1930 to late 1980, 9690 cases of silicosis were accepted by the CNSA. Nearly one half (46%) of these silicotic patients were still alive on December 31, 1980; another third had died of silicosis and the rest of other affections not related The origin of cases has remained remarkably constant over the course of time. Underground working and the stone-working industry account for the majority of cases (70%), followed by smelting works (16%) and the ceramic industry (5%). The remaining 9% are due to various causes. Silicosis hazards have declined but still remain real. In late 1980, 1287 companies in Switzerland were being monitored from this standpoint. More than two-thirds (67%) belong to the stone-working industry (even though only 30% of hazard-exposed workers are employed in this sector), 10% are involved in underground work (10% of hazard-exposed workers), 10% are smelting industries (36% exposed) and 6% belong to the ceramic industry (17% exposed). Since 1950, the number of hazard-exposed people has fluctuated between relatively narrow limits (i.e. 15,000 and 20,000). Corresponding figures for previous periods are not known. Some facts indicate that silicosis is becoming less problematic: a) The annual incidence rate of silicosis in Switzerland has evolved in three distinct phases. From 1930 to 1940 the number of new cases recorded each year rose regularly. From 1940 to the late 1960s, the incidence levelled off (200-300 cases yearly); then, from 1974, it dropped rather sharply and less than 100 new cases have been recorded yearly since 1978 (97 in 1978, 69 in 1979 and 68 in 1980). b) The average age at diagnosis of silicosis has regularly increased. Until 1940, the average age of recorded silicotic patients was about 40. The threshold of 50 years was reached between 1953 and 1957. More recently (between 1978 and 1980) the corresponding figure was 68.2.(ABSTRACT TRUNCATED AT 400 WORDS)

[Current occupational respiratory pathology in Switzerland]. / La pathologie respiratoire professionnelle de nos jours en Suisse.

The main features of occupational industrial respiratory diseases in Switzerland can be summarized as follows: -Silicosis: 9750 cases from 1930 to 1979. At present low annual incidence (less than 100 cases), age at first diagnosis over 40 years, at death almost 70 years. - Asbestosis: 130 cases from 1939 to 1979. 30 cases of mesothelioma (21 without asbestosis; 9 with), 9 of bronchial carcinoma and 1 of gastric cancer in the 130 cases of asbestosis. - Acute toxic lung (irritant gases such as chlorine, phosgene, nitrous gases), occupational asthma, extrinsic alveolitis and finally occupational chronic bronchitis are the principal diseases also observed.