[What is the value of emergency cranial radiography in craniofacial injuries?]

To evaluate the possible overuse of skull films, 344 patients were studied retrospectively and 252 were sent a questionnaire. During the 12 month study, 47 skull fractures were detected in 596 patients who had skull roentgenograms because of head trauma. 42 patients had intracranial sequellae but no skull fracture. The presence of a skull fracture usually has no bearing on management and may give the physician an unwarranted feeling of security. Reasons for unnecessary examinations include medicolegal considerations, inadequate history provided to the radiologist and insufficient physical examination. If neurologic signs are present, computed tomography is the first choice procedure.

[Computed tomography of intracranial epidermoid cysts]

Diagnostic criteria of intracranial epidermoid cysts were established from the observation of 15 cases, confirmed by pathology, seen during the last 5 years. Tumors could be divided into four groups: posterior fossa, supratentorial spaces, transtentorial and extradural. Regions of hypodensity associated with the irregular nature of the outlines of the lesion are generally sufficient to suggest the diagnosis in a pre-operative scan, but certain tumors may be isodense or, more exceptionally, spontaneously hyperdense. Contrast images are extremely rare, and are seen only at the periphery of the lesions. The "mass-effect" is remarkably discrete when compared with the tumor size, sometimes of very large proportions.

[Severe complication of translumbar aortography. Apropos of a case]

A case is reported in which death followed translumbar aortography. The onset of acute ischemia of the lower limbs without thrombosis and of diffuse skin mottling below the level of the puncture are unusual features. These suggest the responsibility of the iodine hydrosoluble contrast medium in the genesis of this lethal complication whose mechanisms are discussed.

Prediction of bovine ovulation by a rapid radioimmunoassay for plasma LH

A commonly used and specific plasma LH radioimmunoassay was modified to provide reliable results for cow LH concentrations in blood within 4-5 h. Blood samples were collected at 2- or 4-h intervals from at least 24 h before the expected oestrus until after its onset. Thereafter, samples were collected at intervals of 2 or 4 days until the next oestrus. For the assay, the antigen-antibody reaction took place during a 2-h incubation at 37 degrees C. The immune complex was precipitated by addition of rabbit anti-gamma-globulin and polyethylene glycol followed by an incubation at 22 degrees C for 30 min. The coefficient of variation between this assay and the standard assay was less than 15%. From a study of 25 cycles from 12 animals, we obtained intervals of congruent to 27.3 h between the beginning of the LH peak and ovulation and congruent to 17.5 h between the end of the peak and ovulation. This modified technique can be used to predict rapidly and precisely the time of ovulation in cattle.

Action of streptomycin and calcium on the apical membrane of hair cells of the frog isolated semicircular canal

An isolated frog posterior semicircular canal was placed in a two-compartment perspex chamber allowing separate perfusions of the peri- and endolymphatic space with adequate saline solutions. The ampullar receptors were mechanically stimulated with a hydraulic device which imposed sinusoidal movements to the cupulo-endolymphatic system at low frequency (0.10 Hz). Slow potentials recorded with non-polarizable Ag/AgCl electrodes near the crista ampullaris (Adc) and on the ampullar nerve (Ndc) were displayed together with an analog signal of the mechanical stimulation and with the nerve spike frequency, on a strip chart. The streptomycin action or the high calcium concentration action (these two substances being administered together or separately into the ampullar space) indicated that the streptomycin seemed to block mechano-dependent channels (non-specific) assumed to be included into the hair cell apical membrane. The synaptic transmission process was altered by streptomycin but was improved by the high calcium concentration. Also, the mechanisms which would control the spontaneous release of a neurotransmitter, seemed, at least partly, different from those controlling the neurotransmitter release in response to a mechanical stimulation; these last ones were less sensitive to the calcium action.

Surgical management of late prosthetic valve endocarditis

Among 32 patients with late prosthetic valve endocarditis selected from two cooperative retrospective studies, ten had valve replacement: six men and four women, mean age being 48 years, ranging from 23 to 65 years old. An emergency reoperation was undertaken for refractory heart failure in seven out of ten cases, with an average delay of 6.6 days after the beginning of antibiotic therapy. In the other three cases, the operation was carried out at the end of 40 days of antibiotic therapy, once for recurrent endocarditis and twice for severe aortic insufficiency. The most common causative micro organism was the staphylococcus (7 out of 10 cases). The infected prosthetic valves were, in 8 out of the 10 cases, in the aortic position. The outcome was poor as the mortality rate was 60% (6 out of the 7 patients operated on in an emergency). Death was attributed to heart failure with conduction disturbances and severe aortic regurgitation (2 cases), cerebral emboli (2 cases), septicopyemia (2 cases). Four patients of the ten, after a mean follow up of 10 months, are cured without prosthetic valve dysfunction. The extreme gravity of prognosis seems related to the microorganism (staphylococcus), to the delay between the beginning of antibiotic therapy and the onset of the fever, and finally to the extension of destructive lesions under the prosthetic valve implantation base; the reimplantation of the prosthesis on frail and abscessed tissue implies a substantial risk of disinsertion. The indications for systematic early reoperation in cases of severe acute heart failure are discussed.

[Radiological aspects of the urinary tract in diabetic patients]

Fifty-two intravenous pyelographic examinations performed in diabetic patients, over a period of ten years, were studied. Certain radiological patterns proved sufficiently specific to be of diagnostic use. The main function of radiology was in follow-up studies and in the detection of complications. A variety of patterns are described: pyelonephritis, renal emphysema, papillary necrosis, perinephric abscess, emphysematous cystitis, fungal infection, neurogenic bladder and calcification in the vas deferens, seminal vesicles, uterine artery and branches of the renal artery. The problem of intravenous injection of iodine contrast media in diabetic patients is discussed and risk factors are described. It is concluded that although iodine contrast media can be harmful, complications are usually mild.

The physiological surveillance of hemodialysis sessions by the continuous measurement of L.F. impedance of the circulating blood (Thomasset's method)

Everybody grants as a fact that hemodialysis disturbances are produced by volemia variations. During H-D the vascular sector is the necessary transit medium to withdraw excessive interstitial water. If this withdrawing is greater than the coming back of the interstitial water into the vascular sector, the plasmatic volume will be decreasing. Thus, to measure the variations of the plasmatic volume in circulating blood it is sufficient to effect a continuous measurement of these ones in a transducer having a definite volume. So, by the mean of an impedancemeter, 5 kHz impedance is continuously measured between the two electrodes of the transducer, because it is known (Thomasset's method) that at 5 kHz current uses only the plasma in order to pass from one electrode to another.

Characterization of a large genomic size Moloney murine sarcoma virus produced by a transformed rat cell line

A rat cell line (78A1) transformed by the Moloney murine sarcoma virus-Moloney murine leukaemia virus (Mo-MuSV-MuLV) complex was found to produce a sarcoma virus different from the isolates previously described. Analysis of intracellular RNA of the 78A1 cell line by electrophoresis on agarose gel, and hybridization with DNA probes specific to M1-Mo-MuSV and v-mosMo sequences revealed a size of 6.7 kilobases (kb) for the RNA of this sarcoma virus. This genome is larger than those of m1, m3, HT1 and 124 isolates and slightly smaller than the myeloproliferative sarcoma virus genome (7.0 kb).

Diverse xenotropic virus expressions in two NZB mouse breeding lines that differ in chromosome breakage

Two breeding lines of the NZB/BI mouse strain, which was originated from Bielschowsky's stock and maintained as a conventional inbred colony since 1963, were developed by selective matings according to chromosome breakage incidence in bone marrow cells. These breeding lines were used because they represent an interesting experimental model, since they differ in the manifestations of the autoimmune process and the incidence of lymphomas. The present study showed that embryos from both breeding lines differed in the expression of the xenotropic type C RNA virus, characteristic of NZB mice. All 17 cultures initiated with embryos from the line showing high chromosome breakage (HB) had positive reverse transcriptase (RT) reactions after cocultivation with an indicator cell line (SIRC). On the contrary, only 3 of the 22 embryos from the line showing low chromosome breakage (LB) had RT activity at late passages (7-10). The chromosome studies done on these embryo cultures showed highly significant differences in the chromosome breakage incidence for the 2 breeding lines [10.6 and 20.5% of cells with aberrations for LB and HB embryos, respectively (P less than 0.001)].

Orthodontic considerations in the treatment of maxillary impacted canines

The purpose of this article is to describe and discuss a relatively unknown and underestimated technical approach to the orthodontic extrusion of impacted canine teeth. It constitutes a preliminary report of a researcher project conducted in our undergraduate clinics on patients treated for orthodontic extrusion of impacted teeth. Of these patients, twenty-seven had maxillary canine impaction, sixteen unilateral and eleven bilateral, for a total of thirty-eight teeth. Some surgical considerations and various fixation appliances for impactions are discussed, as well as the advantages and disadvantages of exerting an extrusive force by means of a Hawley type of removable appliance.

Properties of reference Escherichia coli endotoxin and its phthalylated derivative in humans

The properties of a reference bacterial endotoxin prepared from Escherichia coli and its phthalylated derivative were studied in normal human volunteers infected intravenously with the compounds. The minimal pyrogenic dose of the reference endotoxin is about 0.1-0.5 ng/kg. The increase in white blood cell count, absolute granulocyte count, absolute immature granulocyte count, and concentrations of serum amyloid A, cortisol, and growth hormone was directly related to the concentration of reference endotoxin administered. Phthalylated reference endotoxin up to 1,000 ng/kg (at least 500 ng of the patent compound/kg) was administered to normal human volunteers without significant changes in temperature, white blood cell count, absolute granulocyte count, and concentrations of serum amyloid A, cortisol, and growth hormone. Thus, this study defines biologic properties of the new reference bacterial endotoxin in humans and demonstrates effective detoxification by phthalylation of the present compound.

In vitro and in vivo studies of three antibiotic combinations against gram-negative bacteria and Staphylococcus aureus

The activities of azlocillin, cefotaxime, and amikacin alone and in combination were evaluated in in vitro checkerboard studies, in infected neutropenic mice, and in human volunteers. The combination of cefotaxime plus amikacin was more synergistic in vitro than the others against the Enterobacteriaceae tested, and the combination of azlocillin plus amikacin was more synergistic against Pseudomonas aeruginosa and Staphylococcus aureus. Survival of neutropenic mice infected with Escherichia coli and Klebsiella pneumoniae, respectively, was greater with azlocillin plus amikacin (24 of 40 and 11 of 40) and with cefotaxime plus amikacin (21 of 40 and 17 of 40) than with azlocillin plus cefotaxime (22 of 40 and 3 of 40; P less than 0.05). Median serum bactericidal activity in volunteers receiving these antibiotics alone and in combination was greater than or equal to 1:8 with most agents and with all combinations tested against 10 strains each of E. coli, K. pneumoniae, P. aeruginosa, and S. aureus. These data suggest that clinical trials with combinations of azlocillin or cefotaxime plus amikacin deserve further study in febrile neutropenic patients.

Electrical activity of isolated semicircular canal in the frog. Action of streptomycin

1. An isolated frog semicircular canal was placed in a two-compartment perspex chamber which allowed the fluids bathing the inside (endolymph) and the outside (perilymph) of the canal to be replaced separately. Mechanical stimulation (MS) of the ampullar receptors was performed by sinusoidal cupular movement. 2. Streptomycin sulfate in the perilymph reduced promptly, strongly and reversibly nerve spontaneous activity (SA) recorded on the ampullar nerve. Streptomycin sulfate also reduced reversible and weakly the slow potentials recorded either near the crista ampullaris (Adc) or on the ampullar nerve (Ndc) and the modulation of firing rate (delta Fms) all these activities being evoked by a mechanical stimulation. 3. Streptomycin sulfate injected into ampullar endolymph reduced promptly and strongly the Adc, Ndc, and delta Fms. When its concentration was higher 0.2 mg/ml, the SA was also reduced about 40 min later. 4. It is concluded that streptomycin sulfate alters weakly and reversibly spike generation process and synaptic transmission; it inhibits strongly and reversibly the resting discharge and it inhibits strongly and may be partly reversibly the transduction mechanisms.