Symptomatic linea arcuata hernia.

Hernias are often associated with congenital defects or incisional breakdown. Even though most of the linea arcuata hernias are asymptomatic, we present a rare case of a symptomatic linea arcuata hernia with associated internal herniation of the colon sigmoideum in a woman without previous abdominal surgery.

Chylous leak: a rare complication after axillary lymph node dissection.

The authors present a case of a chylous leak after axillary lymph node dissection. Although this case has been treated conservatively, the authors discuss different treatment approaches.

The use of 'hybrid' allografts in the treatment of fractures of the thoracolumbar spine: first experience.

Harvesting autogenous bone grafts of the iliac crest carries complications and lengthens operative times. Allografts are preferred to avoid these problems. Fusion after using allogenic bone grafts has been well studied, by examining trabeculations and remodelling on anteroposterior and lateral radiographs. However, the question remains whether one can rely on radiographs alone to determine fusion. 'Hybrid' fresh-frozen allografts from the femur or tibia were used in 11 adult patients with a mean age of 56.4 years (range: 30-78 years) to stabilize the thoracolumbar spine after anterior decompression for trauma. In one case two adjacent levels were fractured, in another case two fractures occurred at different levels. Fresh-frozen allografts of the femur (in ten cases) and tibia (one case), filled with autogenous cancellous bone graft or pieces of rib, were used to reconstruct the anterior column of the spine. Stabilization was performed by means of a Kaneda device. Anteroposterior and lateral radiographs and, additionally, computed tomography (CT) examinations with reconstructions were used to study fusion. One patient died 1 month after surgery. At follow-up in ten patients, after a mean time of 30.2 months (range: 18-42 months), ten allografts showed a grade I fusion and one a grade III fusion. Additional data from the CT examination with reconstructions, however, showed cross-trabeculations in all cases, and a partially united allograft in the patient with a grade III fusion. Cross-trabeculations between the allograft and vertebral body was observed at 6 months, with remodelling occurring at approximately 2 years. Mean loss of correction was minimal, at 3.6 degrees (range 0 degree-16 degrees). Fresh-frozen femoral or tibial allografts worked effectively to maintain correction after trauma when combined with anterior instrumentation. CT examinations with sagittal and coronal reconstructions were more effective for evaluation of fusion compared with anteroposterior and lateral radiographs. The high fusion rate and the low morbidity achieved using allografts in this way supports the exclusive use of allografts in the anterior thoracic and lumbar spine in the future.

Functional expression of gastric H,K-ATPase using the baculovirus expression system.

A novel approach to construct a single recombinant baculovirus expressing two protein subunits simultaneously by replacing polyhedrin as well as p10 coding sequences is described. The recombinant baculovirus expressed the alpha- as well as the beta-subunit of the gastric H,K-ATPase. Sf9 cells infected with this virus exhibited a K(+)- and SCH 28080-sensitive ATP-dependent phosphorylation capacity in purified Sf9 membranes similar to native H,K-ATPase. This activity was not present in control membranes containing only one of the two H,K-ATPase subunits. We therefore conclude that both subunits are essential for the phosphorylation capacity of H,K-ATPase.

In vitro expression of bovine opsin using recombinant baculovirus: the role of glutamic acid (134) in opsin biosynthesis and glycosylation.

Expression levels of functional bovine opsin in the insect cell line IPLB-Sf9 using recombinant baculovirus were shown not to depend on the use of novel transfer vectors (pAcRP23, pAcDZ1) that were reported to improve biosynthesis levels of other proteins in this system. A production of 5 micrograms opsin per 10(6) cells (approx. 1.5% of total cell protein) was achieved by batch fermentation of infected cells in spinner cultures. Infection of the cells in the presence of the glycosyltransferase inhibitor tunicamycin led to the synthesis of the complete protein, which, however, now migrated with a substantially lower Mr. This demonstrates that opsin in insect cells also undergoes N-linked glycosylation and allowed partial purification (10-fold) of the resulting rhodopsin by affinity chromatography over Concanavalin A-Sepharose. Through site-directed mutagenesis (rhod)opsin mutants have been obtained allowing dissection of functional domains of opsin. Amino acid substitutions that involved Glu-134 and/or Arg-135 affected the normal biosynthetic process leading in part to nonglycosylated, to a small extent even incomplete, protein. A number of mutations, that involve other charged residues within the second and third transmembrane domain of the protein, had no effect on the biosynthetic processing of the protein. We therefore suggest that the charge-pair Glu-134-Arg-135 is part of an important internal signal sequence and that alterations in this region may result in incorrect membrane translocation and/or folding of the protein.

Asp83, Glu113 and Glu134 are not specifically involved in Schiff base protonation or wavelength regulation in bovine rhodopsin.

Site-specific mutagenesis was employed to investigate the proposed contribution of proton-donating residues (Glu, Asp) in the membrane domains of bovine rhodopsin to protonation of the Schiff base-linking protein and chromophore or to wavelength modulation of this visual pigment. Three point-mutations were introduced to replace the highly conserved residues Asp83 by Asn (D83N), Glu113 by Gln (E113 Q) or Glu134 by Asp (E134D), respectively. All 3 substitutions had only marginal effects on the spectral properties of the final pigment (less than or equal to 3 nm blue-shift relative to native rhodopsin). Hence, none of these residues by itself is specifically involved in Schiff base protonation or wavelength modulation of bovine rhodopsin.