Quality care concerns nation's nurses; support expressed for staff nurses.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to C Alexander.
Explore the source record for details and available documents.
A group of 561 consecutive patients with proven symptomatic peripheral or cerebral arterial disease attending a vascular clinic was screened for abdominal aortic aneurysm (AAA) using B-mode ultrasonography. An aneurysm was present in 40 of 358 men (11.2 per cent) and 13 of 203 women (6.4 per cent), a total prevalence of 9.4 per cent. Thirty-three aneurysms were 3-4 cm in diameter. The prevalence of AAA was similar in patients referred with lower-limb and with cerebral ischaemia. Physical examination for AAA was performed in 200 patients before ultrasonography. The sensitivity of physical examination in the detection of aneurysm was 43 per cent (57 per cent for AAA > or = 4 cm in diameter, 29 per cent for AAA < 4 cm in diameter). Physical examination was an inadequate method of screening. Initial follow-up showed a mean aneurysm expansion rate of 0.20 cm/year. Patients with arterial disease have a high risk of AAA; routine ultrasonographic screening should be considered.
In order to avoid complications after regional chemotherapy (isolated hyperthermic perfusion) of the extremities, rapid measurement of blood leakage from the extracorporeal to the systemic circulation is important. A method using technetium-99m in vivo red blood cell (RBC) labelling is reported that provides results within 3 min. Blood samples drawn from the systemic and the extracorporeal circulation were measured for 99mTc activity using a mobile well counter, and the leakage values calculated. The mean result was 7.6% +/- 6.5%/15 min (n = 209). The corresponding flow rate was 100.2 +/- 85.7 ml/15 min (mean +/- SD). The values for isolation perfusion of the upper and the lower extremities are compared. The leakage results using 99mTc RBC labelling were correlated with other blood pool markers. Iodine-125 human serum albumin and indium-113 m transferrin were administered in subgroups of 4 and 19 patients simultaneously. Using linear regression, the coefficient of correlation was 0.72 for 99mTc/113mIn and 0.58 for 99mTc/125I. Comparison with the alternatives suggests that the rapid method of leakage measurement after 99mTc RBC labelling can be considered one of the most practicable and reliable methods available.
Explore the source record for details and available documents.
The purpose of this study was to examine associations between levels of state and trait anxiety in children with asthma and increased asthma morbidity immediately following an acute asthmatic attack. A total of 155 children, aged 7-12 years, diagnosed with asthma, were administered the State-Trait Anxiety Inventory for Children (STAIC) while the State-Trait Anxiety Inventory Form Y (STAI) was administered to the mother. The mother's state and trait anxiety scores were consistently higher than the child's scores, and there was no significant correlation between child and mother anxiety levels. Almost two-thirds of children reported feeling "panic" at the beginning of the index asthma attack, which was significantly associated with child state anxiety. Health professionals must be sensitive to child as well as maternal anxiety in families of children with asthma.
The sequence of the tufA gene from the extreme thermophilic eubacterium Thermus aquaticus EP 00276 was determined. The GC content in third positions of codons is 89.5%, with an unusual predominance of guanosine (60.7%). The derived protein sequence differs from tufA- and tufB-encoded sequences for elongation factor Tu (EF-Tu) of Thermus thermophilus HB8, another member of the genus Thermus, in 10 of the 405 amino acid residues. Three exchanges are located in the additional loop of ten amino acids (182-191). The loop, probably involved in nucleotide binding, is absent in EF-Tu of the mesophile Escherichia coli. Since EF-Tu from E. coli is quite unstable, the protein is well-suited for analyzing molecular changes that lead to thermostabilization. Comparison of the EF-Tu domain I from E. coli and Thermus strains revealed clustered amino acid exchanges in the C-terminal part of the first helix and in adjacent residues of the second loop inferred to interact with the ribosome. Most other exchanges in the guanine nucleotide binding domain are located in loops or nearest vicinity of loops suggesting their importance for thermostability. The T. aquaticus EF-Tu was overproduced in E. coli using the tac expression system. Identity of the recombinant T. aquaticus EF-Tu was verified by Western blot analysis, N-terminal sequencing and GDP binding assays.
Epidermal growth factor (EGF)-stimulated tyrosine phosphorylation of proteins was examined in cells expressing wild-type (WT-EGFR) EGF receptors or EGF receptors truncated at residue 973 (973-EGFR). A much broader spectrum of tyrosine phosphorylated proteins was found following EGF treatment of 973-EGFR expressing cells compared with cells expressing wild-type receptors. Several additional ras GTPase activating protein-associated tyrosine phosphorylated proteins were found in EGF-treated 973-EGFR cells relative to WT-EGFR cells. Additional tyrosine-phosphorylated proteins were also found to co-immunoprecipitate with phospholipase C gamma 1 (PLC gamma 1) following EGF treatment of cells expressing 973-EGFR relative to cells expressing WT-EGFR. EGF-stimulated tyrosine phosphorylation of PLC gamma 1 was found in cells expressing WT-EGFR, but not in cells expressing 973-EGFR. WT-EGF receptor from EGF-treated cells bound well to bacterially expressed src homology (SH) regions of PLC gamma 1 and to a lesser extent to bacterially expressed GTPase activating protein SH regions. No binding of 973-EGF receptor to SH regions of either protein could be detected. EGF treatment greatly reduced the half-life of WT-EGFR, but had relatively little effect on the half-life of 973-EGFR. EGF induced internalization of 973-EGFR at a slower rate than WT-EGFR and caused the appearance of discrete receptor degradation products for both cell types. The data indicate that truncation of the EGF receptor at residue 973 alters receptor substrate specificity, decreases the rate of receptor internalization, and has an inhibitory effect on receptor degradation.
The pattern of retrograde axonal transport of the target-derived neurotrophic molecule, nerve growth factor (NGF), correlates with its trophic actions in adult neurons. We have determined that the NGF-related neurotrophins, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), are also retrogradely transported by distinct populations of peripheral and central nervous system neurons in the adult. All three 125I-labeled neurotrophins are retrogradely transported to sites previously shown to contain neurotrophin-responsive neurons as assessed in vitro, such as dorsal root ganglion and basal forebrain neurons. The patterns of transport also indicate the existence of neuronal populations that selectively transport NT-3 and/or BDNF, but not NGF, such as spinal cord motor neurons, neurons in the entorhinal cortex, thalamus, and neurons within the hippocampus itself. Our observations suggest that neurotrophins are transported by overlapping as well as distinct populations of neurons when injected into a given target field. Retrograde transport may thus be predictive of neuronal types selectively responsive to either BDNF or NT-3 in the adult, as first demonstrated for NGF.
OBJECTIVE: To develop predictive criteria for successful weaning of patients from mechanical assistance to ventilation, based on simple clinical tests using discriminant analyses and neural network systems. DESIGN: Retrospective development of predictive criteria and subsequent prospective testing of the same predictive criteria. SETTING: Medical ICU of a 300-bed teaching Veterans Administration Hospital. PATIENTS: Twenty-five ventilator-dependent elderly patients with acute respiratory failure. INTERVENTIONS: Routine measurements of negative inspiratory force, tidal volume, minute ventilation, respiratory rate, vital capacity, and maximum voluntary ventilation, followed by a weaning trial. Success or failure in 21 efforts was analyzed by a linear and quadratic discriminant model and neural network formulas to develop prediction criteria. The criteria developed were tested for predictive power prospectively in nine trials in six patients. RESULTS: The statistical and neural network analyses predicted the success or failure of weaning within 90% to 100% accuracy. CONCLUSION: Use of quadratic discriminant and neural network analyses could be useful in developing accurate predictive criteria for successful weaning based on simple bedside measurements.
Although the radiopharmaceuticals used for bone scintigraphy are of very high quality, the search for an "ideal" agent continues. To optimise the detectability of bone lesions, we analysed 244 different 99mTc-labeled phosphonates in animal experiments. In osteosarcoma-carrying rats 99mTc-labeled 1-Hydroxy-3-methyl-phosphinic-1, 1-propanediphosphonic acid (HMPD) was shown to produce the best lesion/normal bone ratio. 99mTc-MDP was used as reference. The ratio was found to be 1.28 for 99mTc-HMPD. The transferability of our results in animals to the situation in man was studied in 10 patients with bone metastases. There was for 99mTc-HMPD an improvement of the lesion/normal bone ratio by more than 60% but also an additional reduction of the soft tissue contrast by about 40%. 15% of the metastases were detected by scintigraphy using 99mTc-HMPD only and not with 99mTc-MDP. The new agent should make possible a better and earlier discrimination of bone lesions in the scintigram.
Experiences with the use of the 99mTc-labelled MAb BW 250/183 in the detection of inflammatory lesions are reported. In 160 of 354 investigated patients the results could be confirmed by other methods. The sensitivity (91%) and the specificity (82%) were very high for a diagnostic tool and were comparable with the results of other leukocyte scans as reported in the literature. The positive predictive value of the method was 93%. In 84 patients studied once and in 6 patients studied twice only one case of the latter group showed a positive HAMA response. It may be concluded that the detection of foci of inflammation with the 99mTc-labelled MAb BW 250/183 is of great diagnostic value and that its administration can be repeated without risk.
In a study of 17 patients with malignant melanomas in the extremities the sensitivity and specificity of a new monoclonal antibody directed at melanoma cells (BW 575, Behring) were investigated. The specificity was 100%, but the sensitivity 70%. In 3 cases known foci could not be detected. All nodular melanomas and their metastases were detected (9 patients). Repeated examination during the first 24 h after injection of the Tc-99m-marked antibody, and two-plane investigations made it possible to detect even small tumors less than 1 cm in diameter and subcutaneous lesions where the melanomas absorbed the antibodies. Due to its high specificity, the antibody seems to be a promising aid in deciding the operative strategy.
Despite wide clinical experience the choice between human umbilical vein (HUV) or polytetrafluoroethylene (PTFE) when the saphenous vein is inadequate remains unclear. In a multi-centre trial of 801 femoro-popliteal bypasses, autogenous vein could not be used in 252 (31%), of which 191 were randomised to either HUV or PTFE and started on aspirin 300 mg plus dipyridamole 150 mg (ASA + DPM) twice daily. Graft patency measured objectively by independent trial coordinators was expressed on an "intention to treat" basis by life table and analysed statistically by log rank and confidence intervals (95% CI). Overall, 101 grafts failed and cumulative patency was 53% (45-61%) at 3 years compared with 60% (55-65%) in 549 vein grafts. Prosthetic bypass patency above knee was 65% (55-75%); markedly better than 35% (23-47%) below knee (p less than 0.001) and comparable with 62% (55-69%) in 217 above knee saphenous vein grafts. Most failures occurred early at a rate of 52/1000 patient-months in the first 3 months (43/1000 for vein) falling to 21/1000 by 6 to 12 months and around 10/1000 subsequently. Randomisation produced comparable groups of 87 HUV and 104 PTFE grafts. Cumulative primary patency for HUV was 68, 63 and 57% at 1, 2 and 3 years, respectively compared with 61, 56 and 48% for PTFE with wide confidence intervals for the difference at 3 years (-20 to 38%, p = 0.27).(ABSTRACT TRUNCATED AT 250 WORDS)
Increased fiber in the diet has been shown in the past to improve bowel function in elderly outpatients and in long-term care institutions. A randomized placebo-controlled, double-blind study was conducted in a geriatric ward of an acute-care hospital to see if a palatable form of fiber would decrease the incidence of constipation and use of laxatives. In this patient sample, no beneficial effect of fiber supplementation could be found when used up to three weeks.
Duration of symptoms, medication use and follow-up medical care were examined over an 8-week period in children following emergency room treatment for an acute asthma episode. Two groups of children were compared: Short-course (N = 90) and Continuous Medication Users (N = 46). Over a third of Short-Course Users continued to report symptoms up to 6 weeks following the index episode with 31% reporting medication use at 8 weeks. Relapse, resulting in an emergency room visit, occurred in 26% of all study children. Factors associated with relapse included maternal smoking, female gender, prior hospitalization for asthma, cough, and medication use during the follow-up period.
The effect of different resting postures on the loading profile of the knee in 1,155 subjects was studied. The recent change to chair sitting has radically modified this profile, resulting in an increase in midflexion loading and virtual disuse of full flexion of knee and hip. Domestic activities do not compensate for this underutilization. There is consistent evidence from 7 communities that the prevalence of osteoarthritis of the hip is substantially lower in communities that do not habitually chair-sit. No other adequate explanation for this difference has been identified. These findings suggest a need to reexamine the incomplete use hypothesis.
This study examined the impact of low birth weight on children's health and assessed the influence of the social environment on various aspects of health in low birth weight and normal birth weight children. Data on 8661 children aged 2 through 11 from the 1981 Child Health Supplement of the National Health Interview Survey provided strong evidence for two major conclusions: (1) Low birth weight children in high-risk social environments are at increased for poor health outcomes compared with comparable normal birth weight children. This vulnerability was found across all age groups, suggesting that the effects of low birth weight are long-lasting. The poor health outcomes for low birth weight children in high-risk social environments were found for all seven aspects of child health status studied: excessive bed days, restricted-activity days, and school-loss days; school failure, low school-ranking, behavior problems, and maternal perception of child health status as fair/poor. (2) The mechanism of risk was complex and differed by birth weight group. Whereas certain combinations of individual risk factors protected normal birth weight children from several adverse outcomes, none for low birth weight children were identified. However, low birth weight children in low- or moderate-risk social environments were not at greater risk for poor outcomes compared with comparable normal birth weight children. This study underscores the importance of a healthy social environment for children who are already at high risk for poor health outcomes by virtue of being low birth weight.
To evaluate the influence of antiplatelet drugs on patency in femoropopliteal vein bypasses, 48 vascular surgeons recruited 549 patients to a randomized double-blind trial of aspirin (300 mg) + dipyridamole (150 mg) or placebo twice daily starting 2 days before surgery and continuing indefinitely. Graft occlusion measured objectively by independent coordinators and cardiovascular events (myocardial infarction or stroke) were studied, expressed by life table, and analyzed statistically by log rank and confidence intervals (95% CI). Randomization achieved comparable groups with 60% of grafts inserted for rest pain or gangrene. Operative complications on aspirin plus dipyridamole included 18 reoperations for bleeding and 12 hematomas compared with 9 and 14, respectively, on placebo (NS). Most of the 172 graft failures occurred early with failure rates of 43/1000 patient-months in the first 3 months, reducing to 17/1000 at 6 to 12 months, and under 10/1000 in subsequent years. Cumulative graft patency on placebo was 72%, 62%, and 60% at 1, 2, and 3 years, respectively, compared with 78%, 70%, and 61% on aspirin plus dipyridamole. The difference in patency of 6.1% (95% CI, -3% to 15.5%) at 1 year and 8.0% (95% CI, -5% to 21%) at 2 years failed to achieve significance (p = 0.43). On mean follow-up of 34 months, 53 (132/1000 patient-years) cardiovascular events (myocardial infarction or cerebrovascular accident) occurred in patients on placebo compared with only 35 (73/1000) on aspirin plus dipyridamole, a significant difference of 59/1000 (p = 0.004). Antiplatelet therapy had little influence on femoropopliteal vein patency, but subsequent myocardial infarction and stroke was reduced in these patients with peripheral vascular disease.