Naso-orbital-ethmoid complex fracture management

Naso-orbital-ethmoid complex fracture management requires a thorough understanding of the anatomy of medial orbital structures, particularly the medial canthal tendon apparatus. Modern C/T imaging allows one to accurately define the fracture patterns present and to plan the surgical repair. The key structure in these fractures is the "central segment" of bone to which the medial canthal tendon attaches. It is essential to identify, anatomically reduce and fixate this fragment to prevent post operative telecanthus. Standard craniofacial surgical approaches allow the surgeon to widely expose these fractures with minimal secondary cosmetic deformities. Rigid fixation of the fracture segments with titanium microplating systems allows for accurate and stable fixation in a one stage surgical repair. The assessment, imaging, surgical exposure, fixation and care of these fractures will be discussed. The goal of repair is to reestablish a normal intercanthal distance and to anatomically repair the associated fractures.

Comparison of sequential compression devices and foot pumps for prophylaxis of deep venous thrombosis in high-risk trauma patients

Multiple-trauma patients are at increased risk for deep venous thrombosis (DVT) but are also at increased risk of bleeding, and the use of heparin may be contraindicated. Sequential pneumatic compression devices (SCDs) are an alternative for DVT prophylaxis. However, lower extremity fracture or soft tissue injury may preclude their use. In these circumstances, foot pumps (FPs) are often substituted, yet little clinical data exist to support their use. We identified 184 consecutive high-risk trauma patients who received DVT prophylaxis with compression devices. We reviewed demographic data, mechanism of injury, Injury Severity Score, injury pattern, and method of prophylaxis. Generally, SCDs were preferred, but FPs were substituted in patients with lower extremity injuries. Occurrences of DVT or pulmonary embolism were also noted. Patients surviving less than 48 hours were excluded. SCDs were used in 118 patients (64%) and FPs in 66 patients (34%). There were no differences in age, Injury Severity Score, or presence of shock on admission. As expected, FP patients were more likely to have lower extremity fractures (65 vs 26%; P < 0.05) and were also more likely to have associated pelvic fracture (59 vs 25%; P < 0.05) and chest injury (61 vs 26%, P < 0.05). There was no difference in the incidence of head injury, although SCD patients had more severe head injuries (Glasgow Coma Score, 7.9 vs 10.5; P < 0.05). The overall incidence of DVT was 5.4 per cent (10 of 184), with no differences between the two groups (SCD 7% vs FP 3%). Three patients had a pulmonary embolism (FP, two; SCD, one), none of which were fatal. Compression devices provide adequate DVT prophylaxis with a low failure rate (3-8%) and no device-related complications. FPs appear to be a reasonable alternative in the high-risk trauma patient when lower extremity fractures precludes use of SCD.

Surgical rehabilitation of facial nerve paralysis

Facial nerve paralysis is a rare and often temporary complication of otologic and neuro-otologic surgery. Associated ocular complications must be avoided to prevent visual loss. When reanastomosis or grafting of the facial nerve is not possible, the VII-XII anastomosis offers reliable reinnervation of the distal facial nerve. For patients whose paralysis has been present for many years, the temporalis muscle transfer provides excellent results. This approach has been proven to give reproducible, aesthetic results with the fewest number of operations.

Rhinologic applications of laser surgery

The use of lasers in the treatment of rhinologic conditions is described. Both intranasal and extranasal laser applications are discussed. The choice of an appropriate laser to suit the clinical situation is also examined.

Ovalbumin messenger ribonucleic acid accumulation in the chick oviduct during secondary stimulation: influence of combinations of steroid hormones and circannual rhythms

We have analyzed by hybridization the accumulation of ovalbumin mRNA after the administration of estrogen, progesterone, these two hormones together, or each hormone with testosterone to "withdrawn" chicks (chicks previously stimulated with estrogen but then withdrawn from the hormone). We were interested in determining if the time lag between hormone treatment and a significant increase in ovalbumin mRNA levels could be shortened. After every hormonal treatment we found that there was a 1.5-2.5-h lag period before a significant increase in ovalbumin mRNA levels. This lag period was not simply due to the slow delivery of the hormone to the oviduct. Nuclear estrogen receptor levels had plateaued by 1 h. Rather unexpectedly, the rate of ovalbumin mRNA accumulation after this lag period seemed to depend on the time of the year. Ovalbumin mRNA accumulated faster during the summer and early fall than during the winter and early spring. These seasonal differences were also observed in ovalbumin mRNA levels 24 h after hormone treatment. Such a circannual rhythm may help explain reported differences in the rate of ovalbumin mRNA accumulation during secondary stimulation.

Chromosomal recombination in Haemophilus influenzae

Haemophilus influenzae cultures doubly lysogenic for defective phage HP1, with a prophage marker sequence +b+/a+c, always contained some free wild-type phage. Single ultraviolet-irradiated cells produced either no wild-type phage or large numbers of them. This suggested that the phage was not released by the original double lysogen but by internal recombinants, i.e., by double lysogens with altered prophage marker sequence such as +++/abc or +b+/++c. Thirty-one wild-type phage-producing clones have been isolated independently from cultures of this double lysogen and identified. They fell in five classes. Two classes, still possessing all three prophage markers, can be explained by Campbell's (1963) prophage recombination model. The other classes had lost one or more markers. They can be explained by interchromosomal double-strand DNA breakage and rejoining. A single-DNA-strand gene conversion model is discussed in view of the fact that genetic transformation involves single-DNA-strand exchanges. A number of potentially interesting mutants has been analyzed of which only the derivatives of rec1 mutant DB117 (obtained from Dr. J. Setlow) were incapable of internal recombination.

Influence of transformability on the formation of superinfection double lysogens in Haemophilus influenzae

Superinfection of growing (nontransformable) cells of defectively lysogenic strains of Haemophilus influenzae with wild-type or with mutant phage HP1 resulted in a number of double lysogens and a small number of monolysogens with altered prophage. The double lysogens were identified by analysis of their monolysogenic segregants and by examining their deoxyribonucleic acid in certain test crosses. The results indicate that the majority had been formed by insertion of the infecting phage genome within the resident prophage. Superinfection of transformable bacteria gave rise to cells with altered prophages (presumably transformants) and to double lysogens which had gained or lost wild-type prophage loci.