Major complications of sinus surgery: a review of 1192 procedures

In a study of bone marrow aspiration smears, Wittchow et al. (Mod Pathol 1992;5:555-558) described a highly characteristic finding, paranuclear blue inclusions (PBIs), found almost exclusively in cases of metastatic small cell undifferentiated carcinoma (SCUC). PBIs are 1-4 microns, light blue, cytoplasmic inclusions best visualized with Romanowsky-type stains. These inclusions are most easily found indenting the nuclei within clusters of closely opposed tumor cells. In the current study air-dried fine-needle aspiration biopsy (FNAB) smears from 146 primary and metastatic small cell and non-small cell adult and childhood malignancies were reviewed. PBIs were found in 28/32 (88%) of SCUC but were observed in only 4/44 (9%) non-small cell carcinomas, 2/21 (9.5%) lymphomas, 1/8 (12.5%) melanomas, 0/14 sarcomas, and 6/27 (22%) small round cell neoplasms. These results suggest that the presence of PBIs in air-dried FNAB smears of adult neoplasms, while not pathognamonic of SCUC, are a diagnostically useful finding. PBIs may be seen in a variety of different childhood small round cell neoplasms which limits their utility in this setting. The recognition of PBIs is most important to the cytologist who may not have access to ancillary studies, such as immunohistochemistry and electron microscopy.     

Herpes labialis in skiers: randomized clinical trial of acyclovir cream versus placebo

Five cases of prenatally detected neck masses that had a potential for airway obstruction at birth are described. The various options for management of the airway are discussed, including using maternal-fetal circulation until intubation, rigid bronchoscopy, tracheotomy, cyst aspiration, or extracorporeal membrane oxygen support. Congenital abnormalities involving the fetal face or neck are extremely rare. With technical advances in ultrasonography, these masses were first noted on prenatal ultrasound in the late 1970s. Before that period, they were detected at delivery. These masses are solid or cystic and may cause asphyxia because of airway obstruction at the time of delivery. The survivability of these neonates without immediate intervention at birth is 0% to 20%. If a neck mass is detected in the fetus by prenatal ultrasonography, then a strategic plan for these types of cases should be developed early in the prenatal period. The airway management plan should be tailored for each individual case. Coordination and the expertise of an obstetrician, neonatologist, anesthesiologist, and pediatric otolaryngologist are needed to manage these complex situations.     

Sinter and sinter-HIP of silicon nitride ceramics with yttria and alumina additions

The sintering behaviour of silicon nitride ceramics has been investigated by preparing powder mixtures containing controlled amounts of yttria and alumina. The fired density of the compacts, having a fixed quantity of yttria, has been observed to increase with increasing amounts of alumina added to the powder. There exists, however, a maximum limit to the beneficial effect of Al₂O₃, because an excess of alumina in the powder mixture does not produce a further increase in density. Sintering of green compacts, obtained by uniaxial pressing, has been carried out at various temperatures and pressures in order to determine the relationship between fired density and the processing variables. The results obtained, after subjecting a selection of specimens to different sinter-HIP cycles, clearly show that the final density is very sensitive to the applied pressure and the time at which it is applied. The range of microstructures produced by different processing routes has also been followed by electron microscopy. From the results obtained by X-ray diffractometry it is shown that the additions of yttria and alumina not only produce denser specimens than pure silicon nitride, but also promote the α-β transformation.     

Mhc-E polymorphism in Pongidae primates: the same allele is found in two different species

The results of 93 de la Caffinière thumb joint replacements in 71 patients were reviewed between 6 and 16 years. The survival rate was 89% at 16 years. Eleven thumb joints had failed requiring revision. The commonest reason for failure was aseptic loosening of the trapezial component. The failure rate was higher in men of working age than any other group, which possibly reflects the increased demands on the prosthesis of these patients. We support the use of this implant for degenerative osteoarthritis, but caution against its use in men under 65 years.     

IQGAP1, a calmodulin-binding protein with a rasGAP-related domain, is a potential effector for cdc42Hs

Proteins that associate with the GTP-bound forms of the Ras superfamily of proteins are potential effector targets for these molecular switches. A 195 kDa protein was purified from cell lysates by affinity chromatography on immobilized cdc42Hs-GTP and a corresponding cDNA was isolated. Sequence analysis revealed localized identities to calponin, the WW domain, unconventional myosins and to the rasGAP-related domain (GRD) contained in IRA, NF-1, SAR1 and rasGAP. p195 was found to be identical to IQGAP1, a protein previously reported to bind ras. Purified recombinant p195/IQGAP1 bound to and inhibited the GTPase activity of cdc42Hs and rac whereas no interaction with ras was detected. The C-terminal half of IQGAP1 containing the GRD bound to cdc42 and rac in a GRD-dependent fashion, but a smaller fragment containing only the GRD did not. Cdc42 was also co-immunoprecipitated from cell lysates with antibody specific to p195/IQGAP1. Calmodulin also co-immunoprecipitated with p195/IQGAP1 and was found to associate with fragments containing the IQ domain. Expression of a cDNA fragment encoding the GRD inhibited the CDC24/CDC42 pathway in yeast, but no effect on ras was observed. In mammalian cells, both endogenous and ectopically expressed p195/IQGAP1 were localized to lamellipodia and ruffling cell membranes, where co-localization with actin was apparent. These results suggest that IQGAP1 is an effector target for cdc42Hs and may mediate the effects of this GTPase on cell morphology.     

Chondrocyte cytokine and growth factor expression in murine osteoarthritis

Eighty-five percent of male STR/ort mice develop osteoarthritic lesions of the knee joint by 35 weeks of age. We have developed a non-radioactive in-situ hybridization method using digoxigenin-labeled oligonucleotide probes to study the expression of the cytokines interleukin (IL) 1 alpha, Il-1 beta and IL-6 and the growth factors insulin-like growth factor-1 (IGF-1) and transforming growth factor beta (TGF beta 1) during the development of osteoarthritis (OA) in this model. Age- and sex-matched CBA mice, which do not develop OA, showed no detectable expression of any of the cytokines or growth factors studied. In contrast, 20-week-old STR/ort mice with no OA lesions showed positive expression [positive: (+)] for all the cytokines and growth factors studied. At 35 weeks of age, STR/ort mice with varying grades of OA showed positive (+) or strong (++) signals for both cytokines and growth factors throughout the tibial articular cartilage. The strongest signal was seen in areas where OA lesions were present. In areas of histologically-normal cartilage adjacent to the lesions, the signals were still positive but weaker. Fifty-week-old STR/ort mice with OA lesions showed a similar pattern of expression to 35-week-old mice. Thirty-five or 50-week-old STR/ort mice with no OA lesions had much reduced expression compared with those with OA lesions. These mice may be indicative of those STR/ort mice which do not develop OA. The results seen in the STR/ort together with previous biochemical analyses are consistent with an up-regulation of anabolic growth factors and catabolic cytokines in the prelesional stages of OA with anabolic effects predominating. At later stages of OA, the effects of catabolic factors appear to predominate and osteoarthritic lesions become evident.