Effect of temperature on blood flow and metabolism in a neurovascular island skin flap

Using the buttock flap in 29 white Yorkshire pigs, blood flow and O2 consumption were measured at dermal temperatures between 35 degrees C and 15 degrees C. Flow was measured with an electromagnetic flowmeter and O2 consumption was calculated as the product of blood flow and the difference in flap A-VO2. Baseline flow was 6.6 +/- .9 (SE) ml/100 g/min at 35 degrees C and 3.1 +/- .02 (SE) ml/10 g/min at 15 degrees C. Blood flow through the flap stopped completely at a dermal temperature of 14 degrees C. Oxygen consumption was 0.16 +/- .02 (SE) ml/100 g/min at 35 degrees C and 0.04 +/- 0.01 (SE) ml/100 g/min at 15 degrees C. At 20 degrees C blood flow was 4.3 ml/100 g/min and metabolism was .04 ml/100 g/min. In other words, blood flow was 65% of baseline, while O2 consumption was only 25% of baseline. The therapeutic effect of local cooling at 20 degrees C deserves further investigation. The cessation of flow at 14 degrees C may be caused by increased plasma viscosity.     

Enzyme immunoassays and related procedures in diagnostic medical virology

This review article describes several applications of the widely used enzyme immunoassay (EIA) procedure. EIA methods have been adapted to solve problems in diagnostic virology where sensitivity, specificity, or practicability is required. Concurrent developments in hybridoma and conjugation methods have increased significantly the use of these assays. A general overview of EIA methods is given together with typical examples of their use in diagnostic medical virology; attention is drawn to possible pitfalls. Recent advances in recombinant DNA technology have made it possible to produce highly specific nucleic acid probes that have a sensitivity approximately 100 times greater than that of EIA. Some applications of these probes are described. Although the non-labelled nucleic acid probes for use in the field are not as refined as non-labelled immunoassays, their range of applications is expected to expand rapidly in the near future.     

Dental caries prevalence in early Polynesians from the Hawaiian Islands

We examined the skeletal remains of 1338 early Hawaiians (preserved in the Bishop Museum, Honolulu) to determine total caries and root surface caries prevalence. Specimens from seven islands were represented in the collection. Estimation of age at death was made by a combination of dental developmental staging for younger individuals and occlusal attrition and/or alveolar bone loss in adults. Museum records were also consulted for age estimation of adults which was primarily based on osteological criteria. The material was divided into six age groups. Predentate infants and edentulous adults were not included. A total of 19,425 teeth was examined. Caries lesions were observed in 462 individuals (34.5%) and 1895 teeth (9.8%). Coronal caries lesions in children and adolescents tended to be small and not particularly destructive of tooth structure. Root surface lesions in young adults were also small but increased progressively in size in the older groups, resulting in pulp exposure and coronal amputation. Although coronal caries was apparently not a significant dental health problem in children and young adults (compared with contemporary Hawaiians), root surface caries was an increasingly important source of tooth morbidity and tooth mortality in the older population groups. This age-related caries pattern was similar for all of the islands.     

Platelet-activating factor stimulates prostaglandin synthesis in cultured cells

The effects of platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) on phospholipase activity were studied in aortic smooth muscle cells and renal epithelial cells. When platelet-activating factor was added to cells prelabeled with [3H]arachidonic acid, it induced rapid hydrolysis of phospholipids. Up to 28% of incorporated [3H]arachidonic acid was released into the medium from both aortic and renal cells. A transient rise of diacylglycerol was also seen after the addition of platelet-activating factor to these cells. The accumulation of diacylglycerol and monoacylglycerol was relatively small when compared with the total amount of released free arachidonic acid. The amount of [3H]arachidonic acid released was comparable to the loss of phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine, which indicates that platelet-activating factor stimulates phospholipase A2 and C activity in aortic smooth muscle cells and renal epithelial cells. Platelet-activating factor also enhanced prostaglandin biosynthesis in these cells.     

Nuclear magnetic resonance proton imaging of bone pathology

Thirty-two patients with diversified pathology were examined with a supraconductive NMR imager using spin echo with different TR and TE to obtain T1 and T2 weighted images. They included 20 tumors (12 primary, eight metastasis), six osteomyelitis, three fractures, two osteonecrosis, and one diffuse metabolic (Gaucher) disease. In all cases except for the stress fractures, the bone pathology was clearly visualized in spite of the normal lack of signal from the compact cortical bone. Nuclear magnetic resonance (NMR) imaging proved to be at least as sensitive as radionuclide scintigraphy but much more accurate than all other imaging procedures including computed tomography (CT) and angiography to assess the extension of the lesions, especially in tumors extended to soft tissue. This is due both to easy acquisition of sagittal and coronal sections and to different patterns of pathologic modifications of T1 and T2 which are beginning to be defined. It is hoped that more experience in clinical use of these patterns will help to discriminate between tumor extension and soft-tissue edema. We conclude that while radionuclide scintigraphy will probably remain the most sensitive and easy to perform screening test for bone pathology, NMR imaging, among noninvasive diagnostic procedures, appears to be at least as specific as CT. In addition, where the extension of the lesions is concerned, NMR imaging is much more informative than CT. In pathology of the spine, the easy visualization of the spinal cord should decrease the need for myelography.     

Scintigraphic detection of occult hemorrhage in a patient receiving anticoagulants

The exact location of hemorrhage complicating anticoagulant therapy is sometimes difficult to establish. We present a case in which imaging with 99mTc-labeled red cells had a significant role in the diagnosis of soft-tissue bleeding in a paraplegic patient receiving long-term anticoagulation.     

Preadmission discharge planning. Organization of a concept

Preadmission testing programs have been developed to recognize and treat medical abnormalities prior to hospitalization, thus reducing preoperative hospital day costs. A preadmission testing program's objectives can be expanded by combining with a discharge planning program. The two programs combined can facilitate discharge planning and patient education prior to hospitalization and coordinate the nursing process. This article will discuss the purposes, organization, and benefits of a preadmission discharge planning program.     

Peracute streptococcal pyomyositis: report of two cases and review of the literature

Pyomyositis occurs infrequently in temperate climates. The fulminating peracute form caused by group A Streptococcus is exceedingly rare. We present two children with streptococcal pyomyositis. One child was admitted in septic shock and required intensive supportive care during the acute stage of his illness. Persistent swelling and tenderness of his left thigh presented a diagnostic problem, which was eventually resolved with the aid of computerized tomography. Despite appropriate antibiotic therapy from the onset of illness, surgical debridement of the affected muscle was necessary. The second child presented with pyomyositis of the left paravertebral muscles and signs of incipient shock but did well on antibiotic therapy alone.