Intraoperative lower extremity compartment pressures in lithotomy-positioned patients.

PURPOSE: Measurement of anterior leg compartment pressures in eight patients (16 limbs) who were positioned in the lithotomy position for prolonged periods of time while undergoing colorectal intra-abdominal surgery. METHODS: Anterior leg compartment pressures were measured in eight patients (16 limbs) by using a slit catheter, whereas subjects were positioned in the lithotomy position for prolonged periods of time while undergoing colorectal intra-abdominal surgery. RESULTS: Compartment pressures had minor elevations after initial lithotomy positioning, and gradually increased over time. Levels elevated to 30 mmHg at an average of five (range, 3.5 to 6) hours. The maximum recorded leg compartment pressure was 70 mmHg. The addition of Trendelenburg positioning was noted to consistently increase compartment pressures. All pressures returned to less than 10 mmHg shortly after removing the limb from the stirrups and placing the limb supine. No patients developed clinical evidence of compartment syndrome. CONCLUSIONS: Leg anterior compartment pressures rise when limbs are placed in the lithotomy position for prolonged periods of time. The rise in pressure is increased with the addition of Trendelenburg positioning. Anterior compartment pressures reached a threshold of 30 mmHg at an average of five hours. The results of this study suggest that lithotomy positioning of the lower extremities has the potential to initiate leg compartment syndrome when the period of positioning approaches five hours. Removing the limbs from the stirrups and placing them in the supine position allows the pressure in the compartments to return to normal.

Unique and shared IgE epitopes of Hev b 1 and Hev b 3 in latex allergy.

Of the several latex proteins cloned and expressed, the rubber elongation factor, Hev b 1, and the closely related Hev b 3, represent two major allergens associated with latex allergy. Although both allergens demonstrated IgE binding with sera from latex allergic patients, it was not known whether these two molecules shared any epitopes. Hence, in the present study using health care workers (HCW) and spina bifida (SB) patients with latex allergy, we investigated the IgE binding epitopes in Hev b 1 and Hev b 3. Recombinant Hev b 1 and Hev b 3 were expressed in a prokaryotic expression system, while overlapping decapeptides of Hev b 1 and Hev b 3 were synthesized on derivatized cellulose membrane. Eight IgE binding epitopes for Hev b 1 and eleven for Hev b 3 were identified using sera from latex allergic patients with SB. On further analysis of synthetic peptides encompassing these epitopes, similar IgE antibody reactivity was demonstrated with three Hev b 1 epitopes b1E3, b1E5, b1E6 and two Hev b 3 epitopes; b3E10 and b3E 11. For Hev b 1, a unique IgE binding epitope was identified in the region of amino acid residues 16-25. In competitive ELISA, peptides bIE2 and bIE4 together inhibited 58% of IgE binding of Hev b 1, while b3E5 showed 22% inhibition in the IgE binding of Hev b 3. The results of the present study suggest that the understanding of linear and conformational IgE epitopes in the major latex allergens may provide better insight into the structure-function relationship of the allergens, and may lead to the development of better patient care and management strategies in latex allergy.

Heterozygous oim mice exhibit a mild form of osteogenesis imperfecta.

The oim strain of mice is one of several rodent models that exhibit an osteogenesis imperfecta (OI) phenotype. These mice have a mutation in the gene encoding alpha-2 chain of type I procollagen that prevents proper assembly of this propeptide with alpha-1 propeptides. Homozygous oim mice experience multiple bone fractures under standard laboratory animal housing conditions and are representative of moderate to severe forms of OI. Because fractures are not typically experienced by heterozygous oim mice, they have not been studied extensively. The present studies show that the organization of cortical bone is deficient in heterozygotes, exhibiting a morphology intermediate to specimens from homozygotes and wild-type mice. The biomechanical properties of femurs isolated from heterozygous oim mice are also intermediate to homozygotes and wild-type mice when tested in four-point bending. Although it is not possible to distinguish visually between heterozygous oim and wild-type mice, the quality and biomechanical properties of bone in heterozygotes is significantly reduced by twelve weeks of age. Heterozygous oim mice are useful as a model for a mild form of OI.

The importance of cultural factors in a brief reactive psychosis.

This paper reviews the case of a time-limited or brief reactive psychosis in a Thai immigrant. Although the patient claimed to have left behind his Thai culture, his previous Buddhist background proved extremely stressful when confronted with a family mortuary ritual. The importance of understanding and working with a patient's previous cultural and religious beliefs is discussed.