Contrast nephrotoxicity: predictive value of urinary enzyme markers in a rat model

Asbestos, proven to be carcinogenic in humans and animals, is reported to have no genotoxic effect. Asbestos workers have an increased risk of lung cancer, mesothelioma, and other tumours. Earlier findings showed that crocidolite can induce DNA strand breaks in cultured rat embryo cells as assessed by nick translation. We investigated DNA double-strand breaks in white blood cells (WBC) of ten workers occupationally exposed to asbestos. According to our results, obtained with neutral filter elution, individuals who had been exposed to asbestos fibres showed two to four times more DNA double-strand breaks (dsb) in white blood cells than ten non-exposed persons. The induced DNA fragments are of about 250 kb (compared to chromosomal DNA of Saccharomyces cerevisiae standard marker). Using additionally the chromosomal DNA protective method of agarose-plugs, DNA fragments in the range of 200 to 1000 kb have been found in the white blood cells of the same ten workers occupationally exposed to asbestos. In the white blood cells of non-exposed subjects no DNA fragments could be detected with this method. Compared to 51 non-exposed persons, elevated anti-ds DNA antibody concentrations were found in ten workers occupationally exposed to asbestos. The fact that workers occupationally exposed to asbestos have distinctly more double-strand breaks and anti-ds DNA antibodies could mean that an increased incidence of DNA-fragments may be an important indicator in the chronic effect of asbestos-associated carcinogenesis. Apparently, the chronic effects of asbestos observed here do not seem to be identical with that of previously reported acute in vitro effects.     

Aortic coarctation associated with a large aneurysm

The stoma following laryngectomy may be placed either within the incision or separately. To determine if this variation had a bearing on its ultimate size, measurements of the stoma size were carried out in 61 patients who underwent laryngectomy by one of these methods. It was found that the stoma was nearly twice the size in patients in whom the stoma had been sited within the main wound and that there was a minimal need for the use of a tube or stoma button post-operatively in these patients.     

Evidence that surface proteins Sn14 and Sn16 of Sarcocystis neurona merozoites are involved in infection and immunity

Sarcocystis neurona is the etiologic agent of equine protozoal myeloencephalitis (EPM). Based on an analysis of 25,000 equine serum and cerebrospinal fluid (CSF) samples, including samples from horses with neurologic signs typical of EPM or with histologically or parasitologically confirmed EPM, four major immunoblot band patterns have been identified. Twenty-three serum and CSF samples representing each of the four immunoblot patterns were selected from 220 samples from horses with neurologic signs resembling EPM and examined for inhibitory effects on the infectivity of S. neurona by an in vitro neutralization assay. A high correlation between immunoblot band pattern and neutralizing activity was detected. Two proteins, Sn14 and Sn16 (14 and 16 kDa, respectively), appeared to be important for in vitro infection. A combination of the results of surface protein labeling, immunoprecipitation, Western blotting, and trypsin digestion suggests that these molecules are surface proteins and may be useful components of a vaccine against S. neurona infection. Although S. neurona is an obligate intracellular parasite, it is potentially a target for specific antibodies which may lyse merozoites via complement or inhibit their attachment and penetration to host cells.     

Laparoscopic cholecystectomy. Do preoperative factors predict the need to convert to open?

We reviewed our experience with the last 587 laparoscopic cholecystectomies performed between May 1990 and January 1993 to correlate preoperative findings that may predict the conversion of a laparoscopic cholecystectomy to that of an open procedure. The prediction of a need to convert to an open cholecystectomy would allow the surgeon to discuss the higher risk of conversion with the patient and also allow for an earlier intraoperative decision to convert if difficulty was encountered. In addition to routine demographic data, ultrasound reports were available for 526 patients and the following information was recorded: presence of stones, thickened gallbladder wall, common bile duct dilatation, gallbladder sludge, and cystic duct impaction. Overall, a two times higher rate of conversion was found for male patients and patients with a body mass index > 27.2 kg/m2. Additionally, a thickened gallbladder wall on preoperative ultrasound was correlated with a six times higher conversion rate to open cholecystectomy. As expected, the positive intraoperative cholangiogram was associated with a higher incidence of conversion. Additionally, finding a dilated common bile duct on ultrasound was found to be associated with a nearly seven times higher rate of positive intraoperative cholangiogram. No statistical significance was found between conversion and age, previous abdominal operations, the presence of stones, common bile duct dilatation, gallbladder sludge, cystic duct impaction, or a distended gallbladder. Thus, these predictive findings allow the surgeon to preoperatively discuss the higher risk of conversion and allow for an earlier judgment decision to convert if intraoperative difficulty is encountered.     

Fibrinogen deficiency reduces vascular accumulation of apolipoprotein(a) and development of atherosclerosis in apolipoprotein(a) transgenic mice

To test directly whether fibrin(ogen) is a key binding site for apolipoprotein(a) [apo(a)] in vessel walls, apo(a) transgenic mice and fibrinogen knockout mice were crossed to generate fibrin(ogen)-deficient apo(a) transgenic mice and control mice. In the vessel wall of apo(a) transgenic mice, fibrin(ogen) deposition was found to be essentially colocalized with focal apo(a) deposition and fatty-streak type atherosclerotic lesions. Fibrinogen deficiency in apo(a) transgenic mice decreased the average accumulation of apo(a) in vessel walls by 78% and the average lesion (fatty streak type) development by 81%. Fibrinogen deficiency in wild-type mice did not significantly reduce lesion development. Our results suggest that fibrin(ogen) provides one of the major sites to which apo(a) binds to the vessel wall and participates in the generation of atherosclerosis.