Resonance Raman detection of structural dynamics at the active site in hemoglobin.

The iron-histidine stretching mode in deoxyhemoglobin displays a large change in frequency and width upon lowering the temperature from 300 to 10 K. The temperature dependence of the data indicates the presence of dynamic process. The dynamics of this mode in frozen hemoglobins can be qualitatively and quantitatively described as a vibrational dephasing via anharmonic coupling to other vibrations of the heme-imidazole system. the effect that occur at the melting transition in the low frequency modes cannot be quantitatively addressed at this point but may be indicative of the introduction of additional degrees of freedom predicated on protein influences that reflect differences in protein quaternary structure.     

Uterus didelphys with a blind hemi-vagina and homolateral renal agenesis

The authors report a case of bicervical bicornuate uterus with a blind hemi-vagina associated with homolateral renal agenesis. A review of the embryology and the various etiopathogenic theories for this rare anomaly are presented and the therapeutic principles are discussed.     

Middle ear pressure variations during nitrous oxide and oxygen anaesthesia

Many authors have reported middle ear pressure variations during inhalation of high concentrations of nitrous oxide. An on-going study on subjects anaesthetized with nitrous oxide and oxygen supplemented with halogens or narcotics and excluding operations on the ear enables us to register three typical curves of middle ear pressure according to the patency of the Eustachian tube. We recorded significant negative middle ear pressures during the recovery period when there was important obstruction of the Eustachian tube. The presence of a tympanic “neomembrane” due to an old perforation associated with important obstruction of the Eustachian tube could lead to a tympanic perforation that may be unnoticed by the anaesthetist if it is not specifically investigated. In our series, we report one case of tympanic perforation and one case of haemotympanum as examples of such consequences.     

R-plasmic transfer from Serratia liquefaciens to Escherichia coli in vitro and in vivo in the digestive tract of gnotobiotic mice associated with human fecal flora.

It was shown that a strain of Serratia liquefaciens harbors a conjugative R-plasmid responsible for reistance to the following 14 antibiotics: ampicillin, carbenicillin, cephalothin, butirosin, neomycin, paramomycin, kanamycin, lividomycin, gentamicin, tobramycin, streptomycin, tetracycline, sulfonamide, and chloramphenicol, which belong to five families, the beta-lactamines, the aminoglycosides, the tetracyclines, the sulfonamides, and the phenicols. Resistance to th 14 antibiotics was cotransferred by in vitro conjugation between S. liquefaciens and strains of Escherichia coli. Mating between S. liquefaciens and E. coli also occurred in vivo, in the digestive tract of axenic mice and gnotobiotic mice associated with the whole human fecal flora. It was also shown that mating between these two strains occurred even when the donor S. liquefaciens strain was only transient in the digestive tract of the gnotobiotic host animals. A dense population of Bacteroides (10(10) viable cells per g of fresh feces) did not hinder this mating. All the matings occurred in the absence of an antibiotic selection pressure, and the resulting transferred strain of E. coli did not have the same colonizing capacity as the recipient parental strain. However, during antibiotic administration to mice, and even after the end of the drug intake, the transconjugant became established in the dominant population and replaced the parental recipient strain.     

Treatment of epidermoid anal canal cancer

Between 1968 and 1979, 183 patients with invasive epidermoid cancer of the anal canal were treated at Institut Curie. There was 156 women, 27 men with a mean age of 67 +/- 11 years (range 40 to 85 years). The initial height of the tumor was less than 4 cm (65 patients), 4 to 6 cm (98 patients), and more than 6 cm (20 patients). All the patients received radiotherapy, either preoperatively or as curative procedure. Twenty-five patients received preoperative radiotherapy, and there was no residual tumor in 9 biopsies obtained at operation. Four local recurrences were observed. One hundred fifty-eight patients received curative radiotherapy, 115 of whom did not undergo operation. Eighty were alive with no evidence of disease and good anal function with a minimum of 3 years follow-up. We observed 15 local recurrences, 4 inguinal recurrences, and 8 visceral metastases. In addition, eight patients initially had such a big tumor that radiotherapy was only a palliative procedure. Forty-three patients required a surgical procedure after this curative radiotherapy. Colostomy (12 patients) or abdominoperineal amputation (25 patients) was required for local recurrence and colostomy was required for necrosis related to radiotherapy. Five year survival was 59 percent. The survival was related to the size of the tumor (p less than 0.0001). The likelihood of retaining normal anal function with local control of the tumor was also closely related to the initial size of the tumor.