Mechanism and stereochemical course at phosphorus of the reaction catalyzed by a bacterial phosphotriesterase.

The reaction mechanism for the phosphotriesterase from Pseudomonas diminuta has been examined. When paraoxon (diethyl 4-nitrophenyl phosphate) is hydrolyzed by this enzyme in oxygen-18-labeled water, the oxygen-18 label is found exclusively in the diethyl phosphate product. The absolute configurations for the (+) and (-) enantiomers of O-ethyl phenylphosphonothioic acid have been determined by X-ray diffraction structural determination of the individual crystalline 1-phenylethylamine salts.

The diagnosis of osteomyelitis in patients with pressure sores.

A prospective blind trial was undertaken to assess the usefulness of commonly used tests to diagnose osteomyelitis underlying pressure sores. Sixty-one pressure sores were studied, with a histopathologic diagnosis from the ostectomy specimen being available in 52. White cell count, erythrocyte sedimentation rate, plain pelvic x-ray, technetium-99m bone scan, computerized tomography, and Jamshidi needle bone biopsy were studied.

Structure and function of Fc receptors on macrophages and lymphocytes.

Cell surface receptors for the Fc portion of immunoglobulin confer on most cells of the immune system the ability to communicate with the humoral antibody response. These Fc receptors are known to be particularly important for the function of various effector cells, such as macrophages, since they are involved in mediating a variety of activities including endocytosis, antibody-dependent cellular cytotoxicity, and triggering the release of potent inflammatory agents. Over the past few years, a considerable amount has been learned about the structure and functions of the Fc receptors expressed by murine and human cells, due to the availability of specific anti-receptor antibodies and the isolation of Fc receptor cDNA clones.

Accelerating recovery after trauma with free flaps.

Free flap versatility and dependability make the final result of microvascular reconstruction highly predictable. Free tissue transplantation should be considered as a primary treatment after trauma. The early use of free tissue transfer will result in fewer operations and a shortened duration of hospitalization in the initial post-trauma period.

Some ancillary procedures for correction of depressed adherent tracheostomy scars and associated tracheocutaneous fistulae.

A procedure for the surgical correction of depressed tracheostomy scars and tracheocutaneous fistulae is described which involves reapproximation of the strap muscles and the selective application of a subcutaneous Z-plasty. The results are predictable, satisfactory, and the procedure is quite simply accomplished. Utilization of the Z-plasty improves contour in patients with atrophic tissue and assists the distribution of tension forces in subcutaneous and muscular layers.

Bisexually concordant, heterosexually and homosexually discordant: a matched-pair comparison of male and female adrenogenital syndrome.

Prenatal hormonal experiments in subprimate species demonstrate conclusively that the pattern of adult mating behavior is masculinized or feminized as a function of prenatal hormonalization of the brain. In primates, especially human beings, postnatal socialization is superimposed on prenatal hormonalization. The syndrome of congenital virilizing adrenal hyperplasia [CVAH] is an experiment of nature in which the fetal brain is prenatally hormonalized by a masculinizing excess of androgen from abnormally functioning adrenal cortices.

Effect of growth temperature on the lipids, outer membrane proteins, and lipopolysaccharides of Pseudomonas aeruginosa PAO.

Growth of Pseudomonas aeruginosa PAO1 at 15 to 45 degrees C in tryptic soy broth resulted in changes in the lipids, lipopolysaccharides (LPSs), and outer membrane proteins of the cells. Cells grown at 15 degrees C contained, relative to those cultivated at 45 degrees C, increased levels of the phospholipid fatty acids hexadecenoate and octadecenoate and reduced levels of the corresponding saturated fatty acids. Furthermore, the lipid A fatty acids also showed thermoadaptation with decreases in dodecanoic and hexadecanoic acids and increases in the level of 3-hydroxydecanoate and 2-hydroxdodecanoate as the growth temperature decreased.

The sural artery and vein as recipient vessels in free flap reconstruction about the knee.

The sural artery and vein were used successfully as recipient vessels in nine patients who required free flap reconstruction about the knee. The anatomy of the sural vessels and the potential advantages of their use as free flap recipients are reviewed and discussed. Indications include popliteal vessels that are absent or severely damaged, as determined by preoperative angiography.

Chronic expanding hematoma.

Two cases of chronic expanding hematoma are presented. Although the location and presentation vary, chronic expanding hematoma has a distinct histopathologic pattern. A diagnosis of neoplasm is suggested by its slow growth pattern.

Monitoring the patient with acute myocardial infarction.

Cardiac monitoring is a vital component in the management of the patient with AMI. Knowledge of the age, location, and extent of an MI and effective use of continuous cardiac monitoring will aid the nurse in anticipating, identifying, and treating potential complications.

The dorsal thoracic fascia: anatomic significance with clinical applications in reconstructive microsurgery.

The anatomic distribution and potential arterial flow patterns of the circumflex scapular artery were investigated by Microfil injection. These studies demonstrated that the circumflex scapular artery lies within the dorsal thoracic fascia, which plays a significant role in the circulation of the overlying skin and subcutaneous tissue. We conclude that scapular/parascapular flaps are fasciocutaneous flaps, the dorsal thoracic fascia can be transferred as a free flap without its overlying skin and subcutaneous tissue, and intercommunication exists between the myocutaneous perforators of the latissimus dorsi myocutaneous flap and the vascular plexus of the dorsal thoracic fascia.

A complementary DNA clone for a macrophage-lymphocyte Fc receptor.

Macrophages, granulocytes and many lymphocytes express or secrete receptors for the Fc domain of immunoglobulins (Ig). These Fc receptors (FcRs) are heterogeneous and can be distinguished on the basis of their cellular distribution and specificities for different immunoglobulin isotypes. Although their functions are not completely understood, FcRs are known to be involved in triggering various effector cell functions and in regulating differentiation and development of B-cells.

Marjolin's ulcer complicating a pressure ulcer: case report and literature review.

Fifteen years after spinal cord injury and 14 years after development of a sacral pressure ulcer in a paraplegic man, a squamous cell carcinoma was found on biopsy during surgical reconstruction of the pressure ulcer. The patient refused the extensive surgery necessary to remove the infiltrating tumor, and the wound was closed with a latissimus dorsi flap. Pressure ulcers remain a problem in spinal cord injured and other disabled patients.

Perioperative complications of elective tracheostomy in critically ill patients.

This study was designed to examine prospectively the incidence of perioperative complications associated with elective tracheostomy in critically ill patients. An experienced surgeon and anesthesiologist participated in every tracheostomy procedure. In 81 procedures, there was no loss of airway control for greater than 20 sec, no airway obstruction, no blood loss exceeding 50 ml, and no aspiration.

Transport of macrophage Fc receptors and Fc receptor-bound ligands to lysosomes.

Mouse macrophage Fc receptors specific for IgG1/IgG2b mediate the binding and pinocytic uptake of soluble IgG-containing antibody-antigen complexes. Internalization of these multivalent IgG complexes is accompanied not only by the intracellular degradation of the ligand, but also by a net decrease in the number of plasma membrane Fc receptors and an accelerated rate of receptor turnover. In contrast, internalized receptors bound to a monovalent ligand, the high affinity Fab fragment of the antireceptor mAb 2.

Computed tomography of dural sinus thrombosis.

The four patients presented here demonstrate the value of contrast enhanced CT in the diagnosis and serial evaluation of dural sinus thrombosis. Two patients were young women using oral contraceptives; another patient had lateral sinus thrombosis complicating mastoiditis; a fourth patient developed superior sagittal sinus thrombosis following hip surgery. Improvements in CT diagnosis, including the use of thin sections for evaluation of the deep venous structures and lateral sinuses complemented by multiplanar reconstruction or direct coronal scanning, are discussed.

Human platelet alpha-adrenergic receptors and responses during pregnancy: no change except that with differing hematocrit.

The possibility that platelet aggregation is altered during pregnancy is controversial. We tested for alterations of alpha-adrenergic receptor-induced platelet function during pregnancy compared to that in the early phase of the menstrual cycle. We found no change in alpha-adrenergic receptor concentration or in affinity of the receptor for epinephrine.

Use of a pedicled parascapular flap for anterior shoulder and arm reconstruction.

We present a case of soft-tissue reconstruction of the shoulder and upper arm utilizing a pedicled parascapular flap and discuss its potential as a flap for regional reconstruction.

Care of pentamadine ulcers in AIDS patients.

Two cases of soft-tissue infection resulting from antibiotic therapy given AIDS patients are presented. Operative treatment resulted in a closed wound in one patient. In the other patient, who suffered from recurrent acute illnesses, nonoperative treatment resulted in slow wound contraction and epithelialization without secondary wound complications.

Management of chronic sternal osteomyelitis.

The management of 2 patients in whom chronic sternal osteomyelitis developed after apparently uncomplicated coronary artery bypass operations is described. Each patient had become totally disabled because of chronic, draining sinus tracts. Eradication of the infection required total sternectomy and excision of all infected costal cartilage.

Neurofibromas of the head and neck.

Twenty patients with neurofibromas of the head and neck have been observed for periods ranging from ten to 25 years. Seventeen patients had classical von Recklinghausen's disease. Of these, ten showed recurrence or appearance of new lesions after surgical resection, whether it was done during childhood or adulthood.

Glycoproteins of the lysosomal membrane.

Three glycoprotein antigens (120, 100, and 80 kD) were detected by mono- and/or polyclonal antibodies generated by immunization with highly purified rat liver lysosomal membranes. All of the antigens were judged to be integral membrane proteins based on the binding of Triton X-114. By immunofluorescence on normal rat kidney cells, a mouse monoclonal antibody to the 120-kD antigen co-stained with a polyclonal rabbit antibody that detected the 100- and 80-kD antigens as well as with antibodies to acid phosphatase, indicating that these antigens are preferentially localized in lysosomes.

Ablation of folliculogenesis in women by a single dose of gonadotropin-releasing hormone agonist: significance of time in cycle.

Effects of single subcutaneous doses (1, 5, 20, and 100 micrograms) of nafarelin, a potent gonadotropin-releasing hormone agonist, on the physiologic events of the human menstrual cycle were studied in 28 normal women. Nafarelin entered the circulation rapidly after injection. Peak concentrations were observed within 1 hour, and the plasma half-life was 4 to 5 hours.

Facial injuries associated with cervical fractures: recognition, patterns, and management.

Publications in both the orthopedic and maxillofacial literature have noted the association of cervical spine and facial injuries. However, because the incidence of spinal injury is low, we found no study which documented the relationship between maxillofacial and cervical spine injuries. The present study reviewed 982 cervical spine injuries in two major trauma centers, finding a 19.