GidA is an FAD-binding protein involved in development of Myxococcus xanthus.

A gene encoding a homologue of the Escherichia coli GidA protein (glucose-inhibited division protein A) lies immediately upstream of aglU, a gene encoding a WD-repeat protein required for motility and development in Myxococcus xanthus. The GidA protein of M. xanthus shares about 48% identity overall with the small (approximately equal to 450 amino acid) form of GidA from eubacteria and about 24% identity overall with the large (approximately equal to 620 amino acid) form of GidA from eubacteria and eukaryotes. Each of these proteins has a conserved dinucleotide-binding motif at the N-terminus. To determine if GidA binds dinucleotide, the M. xanthus gene was expressed with a His6 tag in E. coli cells. Purified rGidA is a yellow protein that absorbs maximally at 374 and 450 nm, consistent with FAD or FMN. Thin-layer chromatography (TLC) showed that rGidA contains an FAD cofactor. Fractionation and immunocytochemical localization show that full length GidA protein is present in the cytoplasm and transported to the periplasm of vegetative-grown M. xanthus cells. In cells that have been starved for nutrients, GidA is found in the cytoplasm. Although GidA lacks an obvious signal sequence, it contains a twin arginine transport (Tat) motif, which is conserved among proteins that bind cofactors in the cytoplasm and are transported to the periplasm as folded proteins. To determine if GidA, like AglU, is involved in motility and development, the gidA gene was disrupted. The gidA- mutant has wild-type gliding motility and initially is able to form fruiting bodies like the wild type when starved for nutrients. However, after several generations, a stable derivative arises, gidA*, which is indistinguishable from the gidA- parent on vegetative medium, but is no longer able to form fruiting bodies. The gidA* mutant releases a heat-stable, protease-resistant, small molecular weight molecule that acts in trans to inhibit aggregation and gene expression of wild-type cells during development.

Baseline reproducibility of B-mode ultrasonic measurement of carotid artery intima-media thickness: the European Lacidipine Study on Atherosclerosis (ELSA).

BACKGROUND AND OBJECTIVE: The European Lacidipine Study of Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multi-national interventional trial to determine the effect of four-year treatment using the calcium antagonist lacidipine versus the beta-blocker atenolol on the progression of carotid atherosclerosis in 2259 asymptomatic hypertensive patients. B-mode ultrasound is used to measure the primary and secondary endpoints including the mean maximum intima-media thickness (IMT) of the carotid bifurcations and the common carotid arteries (CBM(max)), the mean maximum IMT of 12 standard carotid sites (M(max)) and the overall maximum IMT (T(max)). This paper reports the cross-sectional reproducibility of ultrasound measurements at baseline. METHOD: To evaluate measurement reliability, each patient is scanned twice at baseline and again at four annual visits, with 80% of the replicate scans performed by the same sonographer and 20% by a different sonographer; 50% of the replicate scans are read by the same reader and the other 50% by different readers. RESULTS: The overall coefficient of reliability (R) was 0.859 for CBM(max), 0.872 for M(max) and 0.794 for T(max). The reliability for CBM(max) was stable during the 1 3/4-year baseline period (R = 0.848 to 0.953) and was uniform among the 23 field centres (R = 0.798 to 0.926). Intra- and inter-reader reliability were 0.915 and 0.872 respectively, and intra-sonographer reliability was 0.866. CONCLUSION: The results demonstrate that by implementing standardized protocols and strict quality control procedures, highly reliable ultrasonic measurements of carotid artery IMT can be achieved in large multi-national trials.

Silica dust and lung cancer in the German stone, quarrying, and ceramics industries: results of a case-control study.

BACKGROUND: A work force based case-control study of lung cancer was performed in non-silicotic subjects exposed to crystalline silica to investigate the association between silica dust and lung cancer excluding the influence of silicosis. METHODS: Two hundred and forty seven patients with lung cancer and 795 control subjects were enrolled, all of whom had been employed in the German stone, quarrying, or ceramics industries. Smoking was used as a matching criterion. Exposure to silica was quantified by measurements, if available, or otherwise by industrial hygienists. Several indices (peak, average and cumulative exposure) were used to analyse the relationship between the level of exposure and risk of lung cancer as odds ratios (OR). RESULTS: The risk of lung cancer is associated with the year of and age at first exposure to silica, duration of exposure, and latency. All odds ratios were adjusted for these factors. Considering the peak exposure, the OR for workers exposed to high levels (>/=0.15 mg/m3 respirable silica dust which is the current occupational threshold value for Germany) compared with those exposed to low levels (<0.15 mg/m3) was 0.85 (95% CI 0.58 to 1. 25). For the time weighted average exposure the OR was 0.91 (95% CI 0.57 to 1.46). The OR for the cumulative exposure was 1.02 (95% CI 0. 67 to 1.55). No increase in risk was evident with increasing exposure. CONCLUSIONS: This study shows no association between exposure to crystalline silica and lung cancer. The exclusion of subjects with silicosis may have led to dilution with respect to the level of exposure and therefore reduced the power to detect a small risk. Alternatively, the risk of getting lung cancer may be restricted to subjects with silicosis and is not directly linked to silica dust.

Renal cell cancer correlated with occupational exposure to trichloroethene.

A previous cohort-study in a cardboard factory demonstrated that high and prolonged occupational exposure to trichloroethene (C2HCl3) is associated with an increased incidence of renal cell cancer. The present hospital-based case/control study investigates occupational exposure in 58 patients with renal cell cancer with special emphasis on C2HCl3 and the structurally and toxicologically closely related compound tetrachloroethene (C2Cl4). A group of 84 patients from the accident wards of three general hospitals in the same area served as controls. Of the 58 cases, 19 had histories of occupational C2HCl3 exposure for at least 2 years and none had been exposed to C2Cl4; of the 84 controls, 5 had been occupationally exposed to C2HCl3 and 2 to C2Cl4. After adjustment for other risk factors, such as age, obesity, high blood pressure, smoking and chronic intake of diuretics, the study demonstrates an association of renal cell cancer with long-term exposure to C2HCl3 (odds ratio 10.80; 95% CI: 3.36-34.75).

Liver resection with the Sonocut ultrasonic knife.

Previous reports and our findings suggest that resection by ultrasound is of appreciable merit in liver surgery. Blood can be saved and bile leakage diminished as the larger vessels and bile ducts can be skeletonized unharmed, whereas the dissector selectively carries away the parenchyma. Otherwise virtually inaccessible tumours can be approached. The ultrasonic dissector/aspirator does not harm the tissue in depth beyond the resection surface and thus not much devitalized tissue is left in the wound.

Prediction of the stability of minimally displaced fractures of the lateral humeral condyle.

Fractures of the lateral humeral condyle run a great risk of subsequent displacement. This is also true--although to a lesser extent--for primarily non-displaced or minimally displaced (less than or equal to 2 mm) fractures. The present retrospective investigation aimed at defining radiographic criteria in order to predict the stability of non-displaced or minimally displaced fractures in 159 children. The fractures were classified according to radiographic criteria into 3 groups considered to represent stable, ambiguous and unstable fractures. Additional displacement while immobilized in plaster occurred in 2.6 per cent of the fractures classified as stable and in 44.4 per cent of those classified as unstable (p less than 0.001); in the ambiguous group subsequent displacement occurred in 24.1 per cent. It is concluded that the radiographic criteria should be useful to predict the stability of non-displaced or minimally displaced fractures of the lateral humeral condyle in children.

Blunt abdominal trauma and hollow viscus injury in children: the diagnostic value of plain radiography.

Although blunt abdominal trauma is common in children, the G-I tract is involved only rarely. However, this paper deals with a series of 24 cases in whom a hollow viscus was injured. We present the radiological and operative findings as well as the results of subsequent radiological workup in patients who had no surgery. Contrary to the recent trend which stresses early abdominal CT as critically important for guiding treatment we have retained a more conservative attitude. Our present protocol includes plain radiography frequently combined with sonographic screening of the abdomen. In patients with stable vital signs and when necessary, we follow up with scintigraphy. CT is reserved for complicated cases with obscure clinical manifestations which do not fit the plain radiological findings and also cases running an unexpected course.

Barium peritonitis. Experience of five pediatric cases.

Barium peritonitis secondary to perforation of the gut is an infrequent complication of radiological G-I tract examinations. It is thought to imply a high mortality rate. However, this conception seems to be based on data obtained during the early 1950's. More recent case reports and small series indicate a more favourable prognosis depending on effective antibiotics and successful maintenance of severely ill patients. The scant information concerning the fate of pediatric cases warranted presentation of the experience of 5 patients, who all survived. Our approach to treatment and the suggested use of barium studies, in particular barium enema, in obscure abdominal emergency cases are offered.

Large bowel volvulus in children. Review of a case material and the literature.

Four pediatric patients with volvulus of the right colon, and three others with twisting of the sigmoid colon are reported. The clinical manifestations, mainly pain, were vague. Radiological plain film findings were occasionally characteristic, but were in the majority of cases equivocal. An active radiological approach including a supplementary barium enema in any patient with inconclusive plain abdominal roentgenograms will, in addition to other unexpected diagnoses, reveal rare cases of large bowel volvulus. Elective surgical procedures, carried out on viable bowel do not necessarily provide advantages over a non-operative approach. In addition spontaneous reduction of the volvulus may result in permanent cure.

Pulmonary aeration after unilateral fetal ligation of pulmonary artery in neonatal rabbits.

When the pulmonary artery was ligated at the gestational age of 30 days, 9 out of the 17 rabbit fetuses had vital lungs and in 7 of these the lungs were aerated after breathing for 15 min to 1 h. Ligation before this gestational age caused necrotic lungs in all 13 rabbit fetuses. On the basis of this we can conclude that the bronchial circulation is not sufficient to ensure vitality of the fetal lung and the pulmonary circulation does not play a major role in the primary aeration of the lungs at birth.

Ectopic ureterocele in the male infant.

An account is given of a series of ectopic ureterocele present in 14 male infants. The malformation is found to be more complex than in the female. The ipsilateral renal function is severely impaired or abolished and obstruction to the bladder outflow common. Associated dilatation and elongation of the posterior urethra during micturition may result in a valvelike appearance. Eversion of the male ureterocele is common and possible mechanisms to account for this event are discussed.

Foetal connective tissue regeneration. A biochemical study in rabbits.

Foetal connective tissue regeneration was studied by implanting 3 x 10 mm cylindrical viscose cellulose sponges subcutaneously in foetal, newborn, and full-grown rabbits. The implants were removed 2 to 7 days later, the foetal implants all being removed after delivery, and were analysed biochemically. In foetal implants a rapid accumulation of soluble forms of collagen took place, while the relative amount of other tissue proteins remained rather low. Connective tissue regeneration of the newborns ressembled, in this respect, that of the full-growns. The results suggest an enhanced production of miniature type collagen in the context of foetal connective tissue regeneration.