Ventilatory response to severe acute hypoxia in guinea-pigs and rats with high hemoglobin-oxygen affinity induced by cyanate

Laparoscopic pelvic lymph node dissection has been applied as a minimally invasive staging technique for men with prostate cancer. This procedure has been shown to shorten markedly postoperative hospitalization, decrease analgesic requirements and shorten convalescence period compared to open pelvic node dissection. However, the laparoscopic procedure takes longer to perform and many disposable instruments are used, thus increasing the cost. We determine the overall cost of laparoscopic versus open pelvic lymph node dissection. Between January 1989 and April 1992, 61 men underwent only staging pelvic lymph node dissection for cancer of the prostate at a single university teaching hospital. Of these patients 11 and 50 underwent open and laparoscopic pelvic lymph node dissection, respectively. Information from the hospital business office was reorganized into preoperative, intraoperative and postoperative expenses. All individual charges were transformed up or down to the dollar amounts of the 1990 to 1991 fiscal year so as to correct for inflationary changes. Preoperative costs were not significantly different between the 2 operative approaches. Intraoperative expenses were 52% greater if laparoscopic pelvic lymph node dissection was performed and can be explained by the longer operative times and use of disposable instrumentation. However, the postoperative period lasted an average of 1.61 days following laparoscopic pelvic lymph node dissection. Postoperative nursing and analgesic requirements were significantly more for patients undergoing open pelvic lymph node dissection. The overall postoperative costs following open pelvic lymph node dissection were 280% more expensive than for the laparoscopic procedure. The overall total costs were approximately $1,250 more for laparoscopic pelvic lymph node dissection. Wages lost or earned during this period and rapid return to normal activity following laparoscopic pelvic lymph node dissection would, in our opinion, justify this additional cost.     

Molecular structure and stereoelectronic properties of sarmazenil--a weak inverse agonist at the omega modulatory sites (benzodiazepine receptors): comparison with bretazenil and flumazenil

X-ray diffraction and ab initio MO theoretical calculations were used in order to investigate the structural and electronic properties of sarmazenil, a weak inverse agonist at the omega modulatory sites (benzodiazepine receptors). This compound was compared to bretazenil, a partial agonist, and to the antagonist flumazenil on the basis of structural and electronic data. The conformational and theoretical properties (interatomic pi overlap populations, molecular electrostatic potential (MEP), the topology of frontier orbitals, and proton affinity) of these three imidazobenzodiazepinones were determined in order to analyse the stereoelectronic properties in relation with their distinct intrinsic efficacies at the omega modulatory sites.     

Mitochondrial DNA haplotype frequencies in natural and experimental populations of Drosophila subobscura

The evolution of Drosophila subobscura mitochondrial DNA has been studied in experimental populations, founded with flies from a natural population from Esporles (Majorca, Balearic Islands, Spain). This population, like other European ones, is characterized by the presence of two very common (>96%) mitochondrial haplotypes (called I and II) and rare and endemic haplotypes that appear at very low frequencies. There is no statistical evidence of positive Darwinian selection acting on the mitochondrial DNA variants according to Tajima's neutrality test. Two experimental populations, with one replicate each, were established with flies having a heterogeneous nuclear genetic background, which was representative of the composition of the natural population. Both populations were started with the two most frequent mitochondrial haplotypes, but at different initial frequencies. After 13 to 16 generations, haplotype II reached fixation in three cages and its frequency was 0.89 by generation 25 in the fourth cage. Random drift can be rejected as the force responsible for the observed changes in haplotype frequencies. There is not only statistical evidence of a linear trend favoring a mtDNA (haploid) fitness effect, but also of a significant nonlinear deviation that could be due to a nuclear component.     

Intestinal obstruction and peritoneal carcinomatosis after endoscopic resection of transitional carcinoma of urinary bladder

Gut involvement in bladder tumours is low, even exceptional in the presence of surface, low-grade neoplasia. The authors explain their experience in the diagnosis and management of a patient treated endoscopically for a vesical surface tumour which subsequently exhibited peritoneal and gut metastatic seeding. The various mechanisms for gut dissemination of vesical neoplasias and the repercussion of their endoscopic management are discussed.     

Perturbation in the 240Pu/239Pu global fallout ratio in local sediments following the nuclear accidents at Thule (Greenland) and Palomares (Spain)

Diabetes complicates 2-3% of all pregnancies and is associated with an increase in both perinatal morbidity and mortality, though reasons for these adverse outcomes are unknown. Estrogen biosynthesis is a critical factor during pregnancy and is carried out in the placenta via aromatase (cytochrome P450 19A1), which catalyzes the conversion of C-19 androgens to C-18 estrogens. Previous studies have shown that hormones such as insulin-like growth factors and insulin regulate aromatase activity when studied in vitro. Interestingly, levels of these hormones are altered in patients with diabetes. Thus, we hypothesized that the presence of maternal diabetes may alter placental aromatase activity and thus estrogen biosynthesis, possibly serving as one factor in the adverse outcomes of babies born to mothers with diabetes. To this end, we measured the production of 19-hydroxyandrostenedione, 19-oxoadrostenedione and estrone in 30 placental tissues from diabetic patients, using [7-3H]androst-4-ene-3,17-dione as a model substrate for aromatase (P450 19A1). A statistical difference was detected in the percentage of 19-oxoandrostenedione formed between the overt and control groups (P < 0.05). Additionally, NADPH P450-reductase levels were measured in these same tissues to determine whether alterations in this enzyme necessary for aromatase activity could be affected by diabetes. No differences in reductase levels were detected among the patient groups. However, a statistical correlation was found between NADPH P450-reductase activity and the formation velocities of all three estrogen products (P < 0.05). Thus, it appears that the presence of diabetes does not affect placental aromatase activity.     

Central motor conduction evaluation in glycogenosis type III

We report a 20-year-old man affected by glycogenosis type III with distal muscle weakness, more severe in distal leg muscles. The electromyogram showed myopathic features. Nerve conduction studies and central motor conduction after magnetic stimulation of the brain were normal. Our results suggest that there is no involvement of central motor pathways in this disease.