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The frog's inner ear was studied in vivo by high spatial resolution magnetic resonance imaging at 7 Tesla. The vestibule, the internal acoustic meatus, and the auditory tube have been identified. The large otolithic mass contained in the vestibule showed a virtual absence of magnetic resonance signal probably due to its composition of closely packed otoconia.

The present paper reports the results of the first investigation of the semicircular canals in a living, small animal by means of high spatial resolution magnetic resonance imaging. This procedure is noninvasive and allows identification of the endolymphatic and perilymphatic spaces yielding a morphology quite consistent with direct anatomical examination.

The present paper reports on magnetic resonance imaging (MRI) at high spatial resolution of the brown adipose tissue (BAT) in laboratory rodents, in comparison with light and electron microscopy findings. Our aim was to assess whether MRI correlates with the expected ultrastructural differences between newborn and adult BAT. The study was performed on the cervical and the interscapular BAT deposits by means of a nuclear magnetic resonance (NMR)-spectrometer equipped with a high resolution imaging system. Ultrastructural examination of BAT at different ages showed three different patterns of adipocyte ultrastructure in BAT which were associated with different MRI patterns. In BAT, MRI identifies the prevalent type of adipocyte in the tissue providing information consistent with ultrastructural results. Results presented here show that MRI represents a precise and reliable tool to investigate the morphology of tissues in living animals. The safe, non-invasive MRI technique represents a very useful tool in morphological research.

Traumatic atloido-occipital dislocation is usually fatal with immediate cardio-respiratory arrest. The authors report 3 cases of children who survived such a spine injury despite neurological impairment. Clinical and radiological data including Magnetic Resonance Imaging are compared with 18 other cases reported in the literature.

In some reptiles, the hemoglobin oxygen affinity is lowered by CO2 and not by the usual phosphate cofactors. To understand the molecular mechanism of this regulation, Caiman crocodylus hemoglobin's primary structure has been determined. The alignment of the 141 residues of the alpha chain as well as the 146 of the beta chain were obtained by classical method of sequence analysis and are compared with some mammalian, avian, amphibian, and fish hemoglobin chains. Furthermore, from these sequences, it is possible to explain the non-interaction of phosphorylated cofactors with the caiman deoxyhemoglobin on the basis of mutations of the amino acids responsible for their fixation on the beta chain. Among these residues only lysine beta 82 is unchanged. In addition a site has been proposed for the fixation of HCO3- which involves ionic bonds with serine beta 1 and glutamic acid beta 144 (Perutz et al. (1981) Nature 291, 682-684) (1).

Morphological distinction between brown and white adipose tissue was obtained in the rat by MRI at 7 Tesla. Both superficial (subcutaneous) and deep (mediastinal) brown fat was visualized; the level of resolution was less than 1 mm. These results show that MRI is a potentially useful tool for studying the biology of brown adipose tissue in the experimental animal and, prospectively, in man.

The 4 cases reported here are meant to illustrate the value of colour doppler-echocardiography in the diagnosis of ventricular septal rupture consecutive to an anterior myocardial infarction. With this method, the examination begins with colour doppler ultrasound superimposed on two-dimensional echocardiographic images and is completed by pulsed and continuous wave doppler velocimetry. In all 4 patients an abnormal colour doppler flow was visualized from the outset; it started in the left ventricule and crossed the ventricular septum to enter the right ventricule, thus confirming the diagnosis and locating the septal defect. This abnormal flow was easy to recognize. On the apical "4 cavity" projection it followed a semi-circular anti-clockwise course which occurred at each cardiac cycle. The flow was red at first in presystole at the apex of the left ventricule; it became blue in pre- and middle-systole while traversing the septum, then mosaic-like in middle- or end-systole around the septal defect on the right ventricular side, and finally blue again in pre-diastole within the right ventricle. The blue trans-septal flow persisted at least up to pre-diastole. The diagnosis of septal rupture was confirmed at surgery in 3 cases and at right heart catheterization in 1 case. Colour doppler-echocardiography is a simple, efficient and rapid method, superior to contrast echocardiography or pulsed doppler alone, for direct real-time visualization of the shunt. It makes the septal defect easy to locate, and it avoids invasive exploratory manoeuvres in cases where surgery is contra-indicated and/or when coronary angiography is not mandatory.

A study is made in this paper of the prognostic significance of a very low distal index (index 6), revealed by irrigraphy. On the basis of examination of 55 case histories, the patients were divided into two groups A and B as a function of the distal indices at the root of the limb. The amputation rate was very high in both groups, but the prognosis was better in group A where the situation could be improved by restorative surgery at a high level. Analysis of the surgical possibilities has indicated that restorative surgery at a high level is a promising procedure, especially in group A. Surgery at the femoro-popliteal level yielded less satisfactory results because of the often considerable degradation of the arterial bed further downstream. Sympathectomy appears to be a useful supplement to restorative surgery in appropriate cases. The concept of the reduced distal index is also valuable for detecting cases of arteritis which are still well compensated but are in danger of vascular failure (dangerous claudications).

p-Nitrophenyl pent-1-yl ether was metabolized (65-70%) in the presence of liver microsomes from phenobarbital-treated rats to give the 4-(major), 3-(minor), and 2-hydroxypent-1-yl (minor) derivatives which were characterized by g.l.c.-mass spectrometry; O-dealkylation (reflecting 1-hydroxylation) and 5-hydroxylation did not occur to a significant extent. 5,5,5-Trifluorination of the pent-1-yl group markedly reduced the extent of metabolism (to approximately 10%). p-Nitrophenyl 2,2,2-trifluoroethyl ether was virtually completely resistant to microsomal metabolism under conditions where the ethyl analogue was extensively O-dealkylated.