Antoine Marfan and his syndrome: one hundred years later

A high-performance liquid chromatographic (HPLC) method is presented for the simultaneous detection of ubiquinone-9 and 10 in rat tissues such as blood, myocardium, and muscle. After liquid-liquid extraction, the ubiquinones are subsequently analyzed by HPLC with ultraviolet (UV) detection at their maximum absorbance (275 nm). Reference calibration curves in ethanol are used to determine tissular levels of ubiquinones. Because a treatment with HMG-CoA reductase inhibitors is expected to decrease the ubiquinone levels, reference calibration curves are performed to ensure that the ratios (ubiquinone/internal standard) observed in such an experiment could be evaluated directly on a calibration curve. The assay is sensitive (0.0625 microgram/mL), reproducible (4% coefficient of variation for ubiquinone-9 and 6% for ubiquinone-10), and linear up to 20 micrograms/mL (or 100 mg of tissue) for ubiquinone-9 and up to 10 micrograms/mL (or 100 mg of tissue) for ubiquinone-10. The ubiquinone levels in control tissues or blood are within the ranges of those previously reported.     

Localization of the ROMK potassium channel to the apical membrane of distal nephron in rat kidney

BACKGROUND: The apical potassium (K+) channels mediate K+ recycling in thick ascending limb (TAL) and K+ secretion in cortical collecting duct (CCD). Recently, the cDNAs for a family of renal K+ channels, ROMK1, -2 and -3, were identified. Based on the biophysical properties and mRNA distribution, it is believed that these ROMK cDNAs encode the apical K+ channels of TAL and CCD. However, the information for cellular and subcellular localization of the ROMK proteins in these tubules is still not available. METHODS: Paraffin or frozen kidney sections from adult Sprague-Dawley rats were stained by polyclonal antibodies against the N- and C-terminal domain of ROMK. Immunoreactive staining was visualized by color development from horseradish peroxidase reaction. Membrane homogenates from kidney were analyzed by Western blot analysis. RESULTS: The polyclonal antibodies against cytoplasmic epitope of ROMK recognized a approximately 42 kD protein in the membrane homogenates from kidney, but not from liver. Staining by immunocytochemistry revealed that ROMK channels were localized to the apical membranes of the distal nephron in cortex and outer medulla, including thick ascending limb and collecting tubule. ROMK staining was absent in glomerulus, proximal tubule and inner medulla. Double staining of the tissue section with both ROMK-specific and H+-ATPase-specific antibodies revealed labeling of ROMK in the principal cells of the collecting tubules. CONCLUSIONS: These results further strengthen the idea that ROMK channels play important roles in the recycling of K+ in TAL and the secretion of K+ in CCD.     

Virulence of enterohemorrhagic Escherichia coli: role of molecular crosstalk

Many bacterial exotoxins, originally defined by cytopathic effects, may also possess additional biological activities. The capacity of exotoxins to elicit the synthesis and secretion of pro- or anti-inflammatory cytokines may be as important as their direct toxic effects in pathogenesis. One example of such 'molecular crosstalk' occurs between Shiga toxins and the cytokines made in response to these toxins during the development of disease.     

Simplified technique for detection of significant bacteriuria by microscopic examination of urine

A comparative study of microscopic examination of 10 microl (simplified loop technique) and 50 microl (traditional drop technique) of uncentrifuged Gram-stained urine specimens for detection of significant bacteriuria was carried out. The results demonstrated that the 10-microl loop technique can be used as an alternative to the 50-microl drop technique for presumptive diagnosis of urinary-tract infection in bacteriological practice, with the advantages of greater rapidity and ease of performance.     

Partial characterization of the cohemolytic factor produced by Streptococcus uberis and comparison with the CAMP-factor

Exosubstances (cohemolysins) produced by Streptococcus agalactiae (CAMP-factor) and Streptococcus uberis (Uberis-factor) showing hemolytic synergism with beta-lysin produced by Staphylococcus aureus were compared. Cohemolytic activity was evaluated in the supernatants of bacterial cultures, before and after ammonium sulfate precipitation. Sheep erythrocytes sensitized with beta-lysin were used as substrate. The assays were performed in microtiter plates and results were expressed as cohemolytic units/ml. Maximum cohemolytic activity was detected, respectively, after 8 h and 14 h of growth in Columbia broth in S. uberis and S. agalactiae cultures. Cohemolytic activities of both microorganisms showed similarities when submitted to various physical and chemical treatments. They were significantly decreased by heating at 60 degrees C and 100 degrees C, or in presence of trypsin, and were abolished in the presence of Tween 20. Activities were found to be stable in crude supernatants and concentrated preparations maintained at -20 degrees C for 3 months. Differences were related to levels of activity and kinetics of detection during the growth cycle. The results indicate the proteic nature, at least in part, of the Uberis factor. Analysis by PAGE in the presence or absence of SDS allowed us to correlate Uberis activity with a protein band with apparent molecular mass of 42 kDa, while CAMP activity was associated with a protein band of 27 kDa.     

Severe pyruvate kinase deficiency anemia. A case report

BACKGROUND: Pyruvate kinase deficiency is a rare cause of hemolytic anemia and, in its most severe form, requires splenectomy in childhood. During pregnancy, severe cases have been traditionally managed with prophylactic blood transfusions to keep the hemoglobin concentration above arbitrary thresholds of 7-8 g/dL. CASE: A case of severe pyruvate kinase deficiency anemia was managed conservatively without blood transfusions even though the hemoglobin concentration reached a nadir of 6.8 g/dL. The perinatal outcome was good. CONCLUSION: In cases of severe pyruvate kinase deficiency anemia, pregnancy per se might not be an indication for prophylactic blood transfusions.     

45Ca exchange in rat cortex slices in conditions of long-term potentiation

OBJECTIVE: An attempt was made to find out how many operations were performed in Europe in 1995 for congenital heart disease. METHODS: Representatives from the 20 most active European countries which could supply reliable information were contacted. They were asked to contact all surgeons performing significant numbers of operations for congenital heart disease in their country. The numbers of operations on children under and over 1 year operated on with and without cardiopulmonary bypass were collected. No attempt was made to collect more detailed information such as operative mortality as it was felt that many surgeons would be reluctant to give their results and the data would be incomplete. RESULTS: A total of 27,976 operations were recorded, of which 20,318 were performed with cardiopulmonary bypass and 7658 without. The total population of the 20 European countries was 448 million and the mean number of operations performed with cardiopulmonary bypass per million was 45.4. However, the rate varied from 9.1 to 70.1. The percentage of operations on cardiopulmonary bypass performed in the first year of life varied from 9.4% to 44.4%. CONCLUSIONS: The total of nearly 28,000 operations in 1995 is probably an underestimate, but it has been difficult to collect this data at all. Obviously many smaller countries have not been included, and some older patients undergoing operations such as atrial septal defect closure in adult units have been missed. The number of open heart operations per million vary in different countries and this presumably represents differing referral patterns. If their numbers are low in some countries, these results may be helpful in persuading their governments that more resources are needed for congenital heart surgery. It is also interesting to see the variation in the number of operations performed in the first year of life. Those countries with a lower rate may have a backlog of older patients who were previously palliated, or their surgeons may still prefer initial palliation and later correction in some conditions rather than early correction. It is hoped that with better prospective data collection, an assessment can be repeated in 2000.     

Treatment options for chronic prostatitis due to vancomycin-resistant Enterococcus faecium

Prostatitis due to vancomycin-resistant enterococci has not been previously described. Reported here is a case of chronic prostatitis due to Enterococcus faecium, resistant to vancomycin, ampicillin, ciprofloxacin and doxycycline, in a 42-year-old liver transplant recipient. Treatment with a combination of rifampin and nitrofurantoin for 6 weeks resulted in long-lasting cure. Other antimicrobial agents active in vitro against vancomycin-resistant enterococci, such as quinupristin/ dalfopristin and chloramphenicol, are unlikely to achieve sufficient prostatic tissue levels to be successfully utilized for treatment of this condition.     

A randomized, placebo-controlled trial of topical cyclosporin A in steroid-dependent atopic keratoconjunctivitis

OBJECTIVE: This study aimed to investigate the therapeutic effect of topical cyclosporin A (CsA) 2% in maize oil as a steroid-sparing agent in steroid-dependent atopic keratoconjunctivitis. DESIGN: Prospective, randomized, double-masked, placebo-controlled trial. PARTICIPANTS: Twenty-one patients with steroid-dependent atopic keratoconjunctivitis were studied. INTERVENTION: Patients used either topical CsA or vehicle four times daily for 3 months in addition to their usual therapy, and the clinical response was used to taper or stop topical steroids when possible. MAIN OUTCOME MEASURES: Steroid drop usage per week, ability to cease steroid use, scores for symptoms and clinical signs, drop side effects, and overall subjective rating of trial drop by patients and clinician were measured. RESULTS: Cyclosporin A had a greater steroid-sparing effect than did placebo. Nine of 12 CsA patients ceased steroids compared to 1 of 9 placebo patients (P = 0.01), the final steroid use was lower in the CsA group (2.6 +/- 1.4 vs. 27.7 +/- 17.7, P = 0.005), and the mean reduction in steroid use was greater for CsA (85.5 +/- 14.7 vs. 13.9 +/- 16.0, P = 0.005). Clinical signs and symptom scores were reduced to a greater level for CsA. Serious side effects were lid skin maceration in one patient using CsA and an allergic reaction in one placebo patient. Marked blurring of vision after drop instillation was common in both groups, but intense stinging was more common in CsA patients (9/12 vs. 1/9, P = 0.01), limiting frequency of drop use. The clinician rated the trial drops as good or excellent more frequently for CsA (11/12 vs. 0/9, P < 0.0001). CONCLUSIONS: Topical CsA is an effective and safe steroid-sparing agent in atopic keratoconjunctivitis and, despite difficulties in patient tolerance, also improves symptoms and signs.