Removal of subarachnoid blood by the irrigation method.
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Biomedical subjects
Publications and source records attributed to D Johnson.
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OBJECTIVES: 2-Deoxy-2-[F-18]fluoro-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) is widely available as a powerful imaging modality, combining the ability to detect active metabolic processes and their morphologic features in a single exam. The role of FDG-PET is proven in a variety of cancers, including melanoma, but the estimates of sensitivity and specificity are based in the majority of the published studies on dedicated PET, not PET/CT. Therefore, we were prompted to review our experience with FDG-PET/CT in the management of melanoma. METHODS: This is a retrospective study on 106 patients with melanoma (20-87 years old; average: 56.8 +/- 15.9), who had whole-body FDG-PET/CT at our institution from January 2003 to June 2005. Thirty-eight patients (35.9%) were women and 68 patients (64.1%) were men. Reinterpretation of the imaging studies for accuracy and data analysis from medical records were performed. RESULTS: All patients had the study for disease restaging. The primary tumor depth (Breslow's thickness) at initial diagnosis was available for 76 patients (71.7%) and ranged from 0.4 to 25 mm (average: 3.56 mm). The anatomic level of invasion in the skin (Clark's level) was determined for 70 patients (66%): 3, level II; 13, level III; 43, level IV; 11, level V. The administered dose of (18)F FDG ranged from 9.8 to 21.6 mCi (average: 15.4 +/- 1.8 mCi). FDG-PET/CT had a sensitivity of 89.3% [95% confidence interval (CI): 78.5-95] and a specificity of 88% (95% CI: 76.2-94.4) for melanoma detection. CONCLUSION: This study confirms the good results of FDG-PET/CT for residual/recurrent melanoma detection, as well as for distant metastases localization. PET/CT should be an integral part in evaluation of patients with high-risk melanoma, prior to selection of the most appropriate therapy.
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Using the stable xenon-enhanced computed tomography (Xe-CT) method in dogs, we studied local, regional and global cerebral blood flow (LCBF, rCBF and gCBF) in two sham experiments and nine cardiac arrest experiments. Within the same experiments without arrest, gCBF and rCBF values were reproducible and stable. LCBF values varied over time. In group I (n = 4), ventricular fibrillation cardiac arrest (no blood flow) of 10 min was reversed by open-chest cardiopulmonary resuscitation (CPR). In group II (n = 5), ventricular fibrillation cardiac arrest of 12.5 min was reversed by brief closed-chest cardiopulmonary bypass. This was followed by controlled ventilation, normotension, normoxia, normocarbia and normothermia to 4 h (n = 7) or 20 h (n = 2) postarrest. The postarrest CBF patterns were similar in both groups. Open-chest CPR during ventricular fibrillation generated near-baseline gCBF and lower LCBF ranges. During postarrest spontaneous circulation, transient diffuse hyperemia was without low-flow regions, longer in brain stem and basal ganglia than in neocortex. During delayed hypoperfusion at 1-4 h postarrest (n = 9), mean gCBF was 44-60% baseline, rCBF in primarily gray matter regions was 15-49 ml/100 cm3 per min and LCBF voxels with trickle-flow and low-flow values, in percent of CT cut area, were increased over baseline. Global CMRO2 (n = 3 of group II) recovered to near baseline values between 1 and 4 h postarrest, while gCBF and O2 delivery were about 50% baseline (mismatching of O2 uptake and O2 delivery).
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OBJECTIVE: To derive and evaluate prediction models for patients who had undergone coronary artery bypass grafting (CABG) and had a difficult postoperative course. DESIGN: Observational. SETTING: Midwestern hospital specializing in high-risk CABG procedures. PATIENTS: One hundred eighty-three patients who stayed at least 10 consecutive days in the intensive care unit after a CABG procedure. OUTCOME MEASURE: Death within 60 days of surgery. INTERVENTION: None. RESULTS: The final logistic regression prediction models included the following findings: pulmonary capillary wedge pressure, cardiac index, heart rate, urine output, positive end-expiratory pressure, blood urea nitrogen levels, and the arterial pressure of carbon dioxide. The model was able to stratify patients into four risk groups with observed 60-day mortality rates of 0.0% (n = 107), 21% (n = 39), 55% (n = 20), and 88% (n = 17). Preoperative patient information was not associated with prognosis for these patients. CONCLUSIONS: The findings suggest that a risk model that is specific for patients who have undergone CABG and is based on postoperative findings may provide useful prognostic information for patients who are having a difficult postoperative course.
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Part I of our study consisted of sending a survey questionnaire to all members of the American Shoulder and Elbow Surgeons in which specific questions were asked about their technique of surgical repair in patients with anterior instability who had capsular laxity or injury in conjunction with marked inferior laxity. Part II is a description of the technique and preliminary results in 18 patients of a modified anterior-inferior capsular shift technique that tightens the inferior capsule with the shoulder positioned in abduction and external rotation and the superior capsule with the shoulder in adduction and external rotation. Of the members of the Society of the American Shoulder and Elbow Surgeons who responded to the survey, 80% agreed that preservation of external rotation was important and that shoulder position at the time of capsular repair might influence the ultimate range of motion obtained. However, no more than 50% of the respondents agreed on any one position for the arm when repairing the capsule. The most common responses for each position were flexion 0 degrees (49%) (range, 0 degrees to 40 degrees), abduction 30 degrees (24%) (range, 0 degrees to 80 degrees), and external rotation 30 degrees (37%) (range, 0 degrees to 70 degrees). The average postoperative follow-up period for the 18 patients was 27 months (range, 24 to 39 months). Of the 18 patients, 11 (61%) maintained symmetric motion; the others had minimal loss of external rotation compared with that of the contralateral shoulder. Six of eight patients with repair on the dominant side were able to return to full premorbid recreational throwing or racquet sports, and seven with repair on the nondominant side returned to full participation in overhead sports such as basketball and swimming. We conclude that this method of "selective" capsular repair may be a useful guideline to gauge the degree of capsular tightening in patients who have capsular injury or laxity.
Retinal ganglion cells are the projection neurons that link the retina to the brain. Peptide immunoreactive cells in the ganglion cell layer (GCL) of the mammalian retina have been noted but their identity has not been determined. We now report that, in the rabbit, 25-35% of all retinal ganglion cells contain substance P-like (SP) immunoreactivity. They were identified by either retrograde transport of fluorescent tracers injected into the superior colliculus, or by retrograde degeneration after optic nerve section. SP immunoreactive cells are present in all parts of the retina and have medium to large cell bodies with dendrites that ramify extensively in the proximal inner plexiform layer. Their axons terminate in the dorsal lateral geniculate nucleus, superior colliculus and accessory optic nuclei, and these terminals disappear completely after contralateral optic nerve section and/or eye enucleation. In the dorsal lateral geniculate nucleus large, beaded, immunoreactive axons and varicosities make up a narrow plexus just below the optic tract, where they define a new geniculate lamina. The varicosities make multiple synaptic contacts with dendrites of dorsal lateral geniculate nucleus projection neurons and presumptive interneurons in complex glomerular neuropil. This is direct evidence that some mammalian retinal ganglion cells contain substance P-like peptides and strongly suggests that, in the rabbit, substance P (or related tachykinins) may be a transmitter or modulator in a specific population or populations of retinal ganglion cells.
The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.
A device is described which can be attached to all blood bags. Two of these devices are heat-sealed together aseptically at any time during the storage life of the blood unit, and an opening connecting the two is created. In vitro and in vivo studies show that ten passes of a unit of blood through these devices produces no cytological changes and does not alter the in vivo survival of the unit when transfused. Further, if the unit is frozen, then thawed, and even stored at 4 C for five days after thawing, the in vivo survival is still unaffected.
Vitamin C is essential for many enzymatic reactions and also acts as a free radical scavenger. Specific non-overlapping transport proteins mediate the transport of the oxidized form of vitamin C, dehydroascorbic acid, and the reduced form, L-ascorbic acid, across biological membranes. Dehydroascorbic acid uptake is via the facilitated-diffusion glucose transporters, GLUT 1, 3 and 4, but under physiological conditions these transporters are unlikely to play a major role in the uptake of vitamin C due to the high concentrations of glucose that will effectively block influx. L-ascorbic acid enters cells via Na+-dependent systems, and two isoforms of these transporters (SVCT1 and SVCT2) have recently been cloned from humans and rats. Transport by both isoforms is stereospecific, with a pH optimum of approximately 7.5 and a Na+:ascorbic acid stoichiometry of 2:1. SVCT2 may exhibit a higher affinity for ascorbic acid than SVCT1 but with a lower maximum velocity. SVCT1 and SVCT2 are predicted to have 12 transmembrane domains, but they share no structural homology with other Na+ co-transporters. Potential sites for phosphorylation by protein kinase C exist on the cytoplasmic surface of both proteins, with an additional protein kinase A site in SVCT1. The two isoforms also differ in their tissue distribution: SVCT1 is present in epithelial tissues, whereas SVCT2 is present in most tissues with the exception of lung and skeletal muscle.
BACKGROUND: Intraosseous (IO) infusion provides an alternative route for the administration of fluids and medications when difficulty with peripheral or central lines is encountered during resuscitation of critically ill and injured patients. OBJECTIVE: To report the first 50 uses of a new system for emergency IO infusion into the sternum in adults, the Pyng F.A.S.T.1 IO infusion system. METHODS: Six emergency departments and five prehospital emergency medical services (EMS) sites in Canada and the United States provided clinical and/or research data on their use of the IO system in a pilot study of success rates, insertion times, and complications. Indications for use included adult patient, urgent need for fluids or medications, and unacceptable delay or inability to achieve standard vascular access. A basic data set was standardized for all sites, and some sites collected additional data. RESULTS: The overall success rate for achieving vascular access with the system was 84%. Success rates were 74% for first-time users, and 95% for experienced users. Failure to achieve vascular access occurred most frequently in patients (5 of 9) described subjectively by the user as "very obese," in whom there was a thick layer of tissue overlying the sternum. Mean time to achieve vascular access was 77 seconds. Flow rates of up to 80 mL/min were reported for gravity drip, and more than 150 mL/min by syringe bolus. Pressure cuffs were also used successfully, although fluid rate was controlled by clamping the line. Further research on flow rates is needed. No complications or complaints were reported at two-month follow-up. CONCLUSION: These early data indicate that sternal IO infusion using the new F.A.S.T.1 IO system may provide rapid, safe vascular access and may be a useful technique for reducing unacceptable delays in the provision of emergency treatment.
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The role of Pseudomonas aeruginosa in nosocomial infections occurring since 1975 is reviewed. Data from the National Nosocomial Infections Study conducted by the Centers for Disease Control, from individual medical centers, and from the literature were used to compare the relative frequency of occurrence of nosocomial infection caused by P. aeruginosa with that of infection caused by other gram-negative bacilli. The relative frequency of P. aeruginosa as a nosocomial pathogen has increased, although wide variations are seen among individual medical centers. P. aeruginosa continues to be a major pathogen among patients with immunosuppression, cystic fibrosis, malignancy, and trauma. While Staphylococcus aureus has become the predominant pathogen in some large burn centers, P. aeruginosa is the most important gram-negative pathogen. Periodic review of the epidemiology of P. aeruginosa infection is warranted in view of the changing incidence of infection caused by this organism.
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Preventable thermal injuries in professional kitchen workers have been identified, and we have introduced a protective garment. Because of the nature of their occupation, kitchen workers are prone to thermal injuries. It has been our experience that the majority of these injuries are scald injuries on the ankles and dorsum of the feet. We propose that a protective garment, such as a waterproof shoe and garter, could reduce the incidence of these injuries.