Randomized Controlled Trial Comparing the Effects of Far-Infrared Emitting Ceramic Fabric Shirts and Control Polyester Shirts on Transcutaneous PO2.

Our aim was to confirm earlier studies showing tcPO2 to be higher under clothing made with polyethylene terephalate (PET) fabric containing ceramic particles (CEL) compared to standard PET fabric. In previous studies PET garments were donned first to avoid possible persistent effects from ceramic particles. This study randomized donning sequence to avoid bias. METHODS: Subjects were randomized to don either PET shirts first (PETF n=73) or CEL first (CELF n=80), switching garments after 90 minutes. Skin temperature (ST), arterial oxygen saturation (O2sat), and tcPO2 were measured every 30 minutes. RESULTS: Baseline ST and O2 sat were nearly identical in the two groups. Baseline tcPO2 was modestly higher in the CELF group than with PETF: 66.4 ± 18.9 vs. 63.9 ± 18.8 mmHg (n.s). Independent of donning sequence, tcPO2 measurements 90 minutes after wearing CEL were 6.7% higher than after 90 minutes wearing PET (p<0.0003). Sequence analysis found tcPO2 in PETF subjects to gradually rise before and after switching garments, but tcPO2 fell immediately after switching garments in CELF subjects. PETF baseline O2sat of 98.1 ± 1.3 increased insignificantly after 90 minutes, and then increased further to 98.6 ± 0.8 after wearing CEL ninety minutes (p=0.0001). CELF baseline O2sat of 97.9 ± 1.7 increased to 98.5 ± 1.1 90 minutes after donning CEL (p=0.0002) and fell to 98.3 ± 1.0 ninety minutes after switching to PET (p=0.0033). CONCLUSIONS: The ability of ceramic-embedded fabric to induce higher tcPO2 measurements is not due to sequence bias.

Functional patency of autogenous AV fistulas for hemodialysis.

BACKGROUND: Although AV fistulas are the preferred access for hemodialysis and have low complication rates, failure to function remains high and time to first dialysis may be several months. METHODS: Data from a Computerized Patient Record System of patients undergoing AV fistula from October 2000 to March 2006 were reviewed for type of fistula, interval from AV fistula construction to first hemodialysis, patency period, and complication rate. RESULTS: 129 patients were identified who underwent 155 autogenous AV fistula constructions. The average age was 62.1 (range 40-84) years old. 114 radiocephalic and 41 brachiocephalic fistulas were performed. 57 (50%) radiocephalic fistulas allowed successful hemodialysis after an average length of 13+/-5 weeks with a primary patency of 13+/-4 months. 24 (42%) fistulas subsequently thrombosed, 7 (12%) developed fistula stenosis, and 2 (4%) developed steal syndrome. 28 (68%) brachiocephalic fistulas reached successful hemodialysis after 6+/-2 weeks with a primary patency of 16+/-7 months. Eleven (42%) of the brachiocephalic fistulas that reached hemodialysis remained patent while four (15%) thrombosed. Two (8%) brachiocephalic fistulas thrombosed before reaching hemodialysis. There were two incidences (5%) of steal syndrome in the brachiocephalic group with one case being severe leading to tissue loss in the hand. CONCLUSION: Brachiocephalic fistulas were superior to radiocephalic in both time to maturity, primary patency, and functional primary patency. Brachiocephalic fistulas had a higher maturation rate and were less likely to fail once hemodialysis began. Vascular surgeons should develop better patient selection to predict which fistulas will function successfully rather than risk complications of prolonged central catheters.

Pharmacokinetics of hexamethylmelamine in intralipid following hepatic regional administration in rabbits.

Hexamethylmelamine (HMM) is a cytotoxic agent demonstrated to have broad antitumor activity. Poor solubility in aqueous media has precluded significant evaluation of parenteral administration of this drug. A formulation of HMM dissolved in Intralipid has demonstrated excellent tolerance following parenteral administration. The goal of this study was to evaluate the pharmacology of HMM in Intralipid following hepatic regional administration. The routes of administration were intraarterial via the hepatic artery with and without arterial occlusion, i.v. via the portal and jugular veins, and i.p. All animals received a total dose of 10 mg HMM/kg of body weight. Hepatic extraction of HMM was most evident via the portal vein (PV) route [AUC(PV)/AUC(i.v.) = 0.5; P less than 0.05]. Lower plasma levels and areas under the curve (AUCs) were observed for the hepatic artery and hepatic artery-stop flow groups when compared to i.v., but the difference was not significant. Administration i.p. yielded low plasma levels but a very long half-life (88 min). Hepatic tissue levels were highest in the group receiving HMM by the hepatic artery-stop flow route. We conclude that the HMM-Intralipid mixture is well tolerated, that HMM is extracted to a significant degree by the liver following PV administration, and that an i.p. installation of HMM-Intralipid results in prolonged plasma drug levels. This preclinical study supports further efforts at evaluation of parenteral administration of the HMM-intralipid mixture.

Yield of repeated screening for abdominal aortic aneurysm after a 4-year interval. Aneurysm Detection and Management Veterans Affairs Cooperative Study Investigators.

BACKGROUND: Little is known about the rate at which new abdominal aortic aneurysms (AAAs) develop or whether screening older men for AAA, if undertaken, should be limited to once in a lifetime or repeated at intervals. METHODS: A large population of veterans, aged 50 through 79 years, completed a questionnaire and underwent ultrasound screening for AAA. Of these, 5151 without AAA on the initial ultrasound (defined as infrarenal aortic diameter of 3.0 cm or larger) were selected randomly to be invited for a second ultrasound screening after an interval of 4 years. Local records and national databases were searched to identify deaths and AAA diagnoses made during the study interval in subjects who did not attend the rescreening. RESULTS: Of the 5151 subjects selected for a second screening, 598 (11.6%) had died (none due to AAA), and 20 (0.4%) had an interim diagnosis of AAA. A second screening was performed on 2622 (50.9%), of whom 58 (2.2%; 95% confidence interval, 1.6%-2.8%) had new AAA. Three new AAAs were 4.0 to 4.9 cm, 10 were 3.5 to 3.9 cm, and 45 were 3.0 to 3.4 cm. Independent predictors of new AAA at the second screening included current smoker (odds ratio, 3.09; 95% confidence, 1.74-5.50), coronary artery disease (odds ratio, 1.81; 95% confidence interval, 1.07-3.07), and, in a separate model using a composite variable, any atherosclerosis (odds ratio, 1.97; 95% confidence interval, 1.16-3.35). Adding the interim and rescreening diagnosis rates suggests a 4-year incidence rate of 2.6%. Rescreening only in subjects with infrarenal aortic diameter of 2.5 cm or greater on the initial ultrasound would have missed more than two thirds of the new AAAs. CONCLUSIONS: A second screening is of little practical value after 4 years, mainly because the AAAs detected are small. However, the incidence that we observed suggests that a second screening after longer intervals (ie, more than 8 years) may provide yields similar to those seen in initial screening and therefore warrants further study.

Human B lymphocytes in giemsa stained preparations.

A mixed antiglobulin procedure has been developed to provide simultaneous study of cell surface immunoglobulin and detailed cytological features in Giemsa stained preparations. The percentage of surface immunoglobulin bearing lymphocytes, monocytes and granulocytes changed dramatically when lymphocytes were incubated at 37 degrees C, or following sheep erythrocyte rosette enrichment procedures.

Effect of dopamine on renal blood flow and cardiac output.

OBJECTIVE: To characterize the relationship between changes in renal blood flow and cardiac output induced by dopamine, hypothesizing that at low doses renal blood flow changes more than cardiac output. DESIGN: Anesthetized swine had renal blood flow and cardiac output measured during either continuous dopamine infusions (2 to 8 micrograms/kg per minute) or bolus dosing (1 to 16 micrograms/kg), and increases in both were compared. Two different fluid protocols were compared using constant dopamine infusions. In the constant pulmonary capillary wedge pressure protocol, intravenous fluids were titrated to keep this parameter constant. In the other protocol, fluid therapy was held constant at 10 mL/kg per hour. RESULTS: With infusions, mean increases in renal blood flow and cardiac output were relatively equal. The maximum increase was 35% at 8 micrograms/kg per minute under the constant pulmonary capillary wedge pressure protocol, with no significant differences (P > .1) found between the change in renal blood flow and cardiac output at any dose in either protocol. With bolus dosing, renal blood flow increased significantly more than cardiac output at 1, 4, and 8 micrograms/kg (P < .05). CONCLUSION: Disproportionate increases in renal blood flow compared with cardiac output at low bolus doses show initial renal responses to be independent of cardiac output. The infusion data suggest that renal responses exhibit tachyphylaxis or that cardiac output slowly accommodates to decreased total peripheral resistance.

Three-year outcome of endovascular treatment of superficial femoral artery occlusion.

HYPOTHESIS: Patency after primary percutaneous transluminal angioplasty (PTA) and stenting of superficial femoral artery (SFA) occlusions is better than historical experience with PTA alone. DESIGN: Consecutive case series of primary PTA with stenting, and follow-up with duplex imaging every 6 months (mean +/- SD follow-up, 32 +/- 15 months). SETTING: Veterans Affairs medical center. PATIENTS AND METHODS: Patients were 57 previously untreated men with 71 limbs having chronic atherosclerotic SFA occlusion with suprageniculate reconstitution and patent tibial runoff. Critical ischemia (Society for Vascular Surgery [SVS] category, 4-6) was present in 7 (10%), the remainder had intermittent claudication only (SVS, 1-3). INTERVENTIONS: Guidewire recanalization followed by PTA, Wallstent deployment, and adjunctive thrombolysis as necessary; 19 limbs (27%) required thrombolysis to manage periprocedural thrombosis. MAIN OUTCOME MEASURES: Cumulative patency, limb salvage, and complications. RESULTS: Length (mean +/- SD) of occlusion was 14.4 +/- 9.9 cm. Length of stented artery was 24.3 +/- 11.1 cm. Ankle brachial index increased from 0.59 +/- 0.14 to 0.86 +/- 0.16 (P<.001) after stenting. One- and 3-year patencies were as follows: primary, 54.6% +/- 6.3% and 29.9% +/- 6.6%; assisted primary, 72.3% +/- 5.6% and 59.0% +/- 6.8%; and secondary, 81.6% +/- 4.8% and 68.3% +/- 6.5%. Three-year secondary patency when periprocedural thrombolysis was required was 35.7% +/- 12.5% compared with 70.6% +/- 7.4% for limbs not requiring periprocedural thrombolysis (P=.02); the differences in occlusion length and severity of ischemia were not significant between these 2 groups. Limbs undergoing adjunctive PTA during angiography 6 to 12 months after initial stenting had 63.0% +/- 13.3% patency at 3 years compared with 100% patency in limbs not requiring PTA at 6 to 12 months angiography (P=.046). Periprocedural mortality and morbidity were 2.8% and 15.5%, respectively. Three of the 7 limbs with critical ischemia underwent amputation during follow-up compared with 2 (3%) of 64 limbs with functional ischemia (chi(2) test, P<.006). A mean of 1.8 endovascular interventions per limb were performed. CONCLUSIONS: Percutaneous transluminal angioplasty and stenting yielded higher patency rates than historical controls undergoing PTA alone. When periprocedural thrombolysis is required, subsequent patency appears to be significantly worse. Poor results after PTA and stenting of limbs with critical ischemia and the need for additional endovascular therapy limit the technique's utility.

Determinants of patency after percutaneous angioplasty and atherectomy of occluded superficial femoral arteries.

BACKGROUND: Patients undergoing percutaneous recanalization of chronically occluded superficial femoral arteries were studied to determine which factors correlated with 1-year patency. Immediate change in ankle:brachial index (ABI), length of occlusion, tibial run-off, and the performance of supplemental catheter atherectomy were evaluated. METHODS: Eligible patients had at least one patient tibial run-off vessel and the absence of limb-threatening ischemia. Recanalization was performed via passage of a guidewire followed by balloon angioplasty. Tibial run-off was scored based on a modification of the angiogram scoring system of the Society for Vascular Surgery and the International Society for Cardiovascular Surgery. Supplemental transcutaneous extraction catheter atherectomy was randomly assigned to a sub-group of patients after initial experience with the recanalization technique. Clinical follow-up was employed to determine patency. RESULTS: Forty-two of 57 attempts (74%) at recanalization were immediately successful. Overall 1-year patency was 40% in 40 limbs that could be followed. In limbs with balloon angioplasty alone (n = 23), patency was 43% compared with 35% in those having supplemental atherectomy. Tibial run-off did not vary significantly between patent and occluded groups. When ABI increased by 0.3 or more, patency was 56% compared with 26% when the ABI increase was less than or equal to 0.1 (P = 0.13). Occlusion length averaged 18.1 +/- 10.6 cm for all limbs and did not vary significantly between early successes and failures. Limbs with short occlusions (less than or equal to 5 cm, n = 8) had 63% patency compared with 38% patency for limbs with long occlusions (greater than 25 cm, n = 16), but the difference was not significant by analysis of variance. CONCLUSIONS: An initial change in ABI was most predictive for patency, whereas no correlation with tibial run-off was demonstrated. Atherectomy did not increase patency. Short occlusions were more likely to remain patent than long ones, but overall patency was lower than described in other series.

Changes in internal carotid blood flow after carotid endarterectomy correlate with preoperative stenosis.

BACKGROUND: The relationship between preoperative stenosis and the effect of carotid endarterectomy (CEA) upon internal carotid blood flow (ICF) is not well understood. With the intention of better characterizing this, we compared intraoperative measurements of internal carotid blood with the maximum single diameter stenosis found in preoperative angiograms. METHODS: Fifty-two patients undergoing 64 carotid endarterectomies (12 bilateral) had transit-time ultrasound perivascular probes used to measure ICF before and after CEA, and the percent change in ICF (% delta ICF) achieved was calculated. Maximum single-diameter stenosis was determined by comparing the least diameter in the flow path from the common carotid to the normal-appearing internal carotid just distal to bifurcation disease. RESULTS: The entire group had a mean of 53 +/- 21% stenosis found on preoperative angiograms, and % delta ICF averaged 64 +/- 92%. When divided into subgroups based on degree of stenosis, patients with 0% to 40% stenosis (n = 17) had % delta ICF of 32 +/- 46%, patients with 41% to 70% stenosis (n = 30) had % delta ICF of 72 +/- 105%, and patients with more than 70% stenosis had % delta ICF of 168 +/- 160%. The differences in % delta IC were significant for the > 70% group compared with the other groups (analysis of variance, P < 0.005), and marginally significant (P = 0.056) between the 0% to 40% and the 41% to 70% groups. The scatter plot of % delta ICF versus stenosis showed a significant second order direct correlation (r = 0.428, P < 0.001) and disproportionate increases in ICF above 60% stenosis. CONCLUSION: A curvilinear relationship between stenosis and immediate increase in ICF after CEA was demonstrated in agreement with theory, and in those patients with more than approximately 60% single-diameter stenosis, large disproportionate increases in blood flow were more frequently observed.

Effects of stenosis on transit-time ultrasound measurements of blood flow.

Measurement of blood flow with transit-time ultrasound near atherosclerotic stenosis sometimes yields anomalous results. The flow-versus-time waveform develops a chaotic pattern obscuring its pulsatile character, and the measured average flow may be less than the real flow thought present. Believing that disturbed flow secondary to atherosclerotic stenosis interferes with transit-time measurements, we investigated the effects of stenosis in a bench model of arterial flow. The average flow measurements and flow-versus-time waveforms produced by the transit-time flowmeter were studied in relation to: (1) the position of the transit-time probe proximal or distal to a stenosis; (2) the choice of filters employed to process the analog output from the flowmeter; and (3) the severity of the stenosis. The results confirm that high grade (> 50%) stenosis creates a characteristic chaotic artifact in the transit-time waveform and, when severe, causes an underestimation of flow.

Spinal cord injury increases the risk of abdominal aortic aneurysm.

We have observed apparently disproportionate numbers of abdominal aortic aneurysms (AAAs) in chronic spinal cord injury (SCI) patients. To test whether aortic enlargement is more frequent in SCI, we measured maximum infrarenal aortic diameters (AoDmax) by B mode ultrasound in 89 SCI subjects and 223 age and sex matched controls. The average AoDmax in SCI subjects (mean age 60.3 years) was 2.27+/-0.80 cm compared to 2.07+/-0.69cm in the controls. This difference was significant (P = 0.023), as were the proportions of subjects with AoDmax >/- 3cm. A total of 20.2 per cent of the SCI group had AoDmax >/- 3cm compared to 8.9 per cent for the controls (P < 0.0001, chi-square). Race, height, and weight distributions were similar. SCI patients had lower levels of hypertension and cigarette smoking than controls. Within the SCI and control groups, subjects with AoDmax >/- 3cm had increased cigarette consumption compared to /- 3cm group than in the >/- 3cm group, T6 versus T8, but not significantly (P = 0.23)> Based on these results, SCI patients have over a two-fold risk of aortic enlargement as a consequence of spinal cord injury.

Characteristics of cancer cells in gastrointestinal lavage specimens.

Cancer cells from the effluent stools resulting from oral gastrointestinal lavage were analyzed. Cellular preparation were done by cytocentrifugation. The method produced cellular preparations that contained from none to 205 cells per slide; the average number was 28. Single cells predominated over groups. The average number of single cells was 13, while three groups were identified on the average slide. The cells were small and averaged 13 microns in diameter and 149 microns 2 in area. The nuclei averaged 8 microns in diameter and 61 microns 2 in area. The nuclear chromatin pattern varied from dense to clumped to vesicular, with the clumped pattern predominating. The technique is simple and easily adaptable and holds promise as a screening technique for gastrointestinal cancer.

Women's knowledge of Papanicolaou smears.

In this survey women were questioned about their knowledge of Papanicolaou (Pap) smears. The findings demonstrate that women have a reasonably good general knowledge about Pap smears but a poor specific knowledge. These results have important public health implications and emphasise the need for greater communication between doctor and patient.

Refinements to the partitioning of the inbred genotypic variance.

Natural gene flow is often localised because of gamete dispersal limitations, and the quantity and structure of the genotypic variance in such populations is a key to predicting the advance from selection, in both evolution and artificial breeding programmes. Earlier derivations of this variance have shown that the total dominance variance may increase with inbreeding despite the fact that heterozygosity is decreasing. This anomaly has been corrected following the de novo biometrical derivation presented in this paper. The whole population also subdivides into descendant lineages that differ in allele frequencies and means because of the dispersion caused by genetic drift and continuing localisation of gamodemes. The paper defines for the first time the among-line and within-line partitions of the dominance variance; and corrects anomalies in the total genic (additive genetic) variance, and its underlying inbred average alle-substitution effect. The revisions also clarify the connections between the Fisher-Falconer, Mather-Hayman, and Wright approaches to defining the inbred genotypic variance. Relationships are discussed between the population dispersion structure and genetic efficiency in selection.

Quantitative genetics of autogamous F2.

General quantitative genetic properties are derived for the F2 originating from self-fertilisation of hybrid (F1) individuals. These results extend and generalize previous restricted knowledge about this F2. New equations are found for all genotype frequencies, allele frequencies, inbreeding coefficient, genic (additive-genetic) and dominance variances, broadsense and narrowsense heritabilities, and selection potential. The bulk mean is generally lower, and the genotypic variance is generally higher, than those of the F1 and the allogamous F2. Genic and dominance variances for the selfed F2 are very different to the classical counterparts. Their relationships with inbreeding have been investigated, and they are more elaborate than previously considered. The level of inbreeding is constant irrespective of parental combinations, which is different to the inbreeding of an allogamous F2. Selection potential is generally high, and selection advance generally exceeds bulk inbreeding depression. If selection is assisted by dispersion, the autogamous F2 may obtain greater genetic advance than its allogamous counterpart for the same selection pressure. Under conditions of spatially separated F2, swarms, natural selection may be enhanced by selfing.

Quantitative genetics of allogamous F2: an origin of randomly fertilized populations.

The quantitative genetic properties are derived for the bulk F2 originating from random fertilization (RF) amongst hybrid (F1) individuals. Only its mean appears to have been derived previously, and that definition is confirmed (by another method). New general equations are found also for all genotype frequencies, allele frequencies, inbreeding coefficient, the genotypic, additive-genetic and dominance variances, and broad-sense and narrow-sense heritabilities. The assumption that such an F2 is a classical RF population is shown to be correct. Indeed, the allogamous F2 is a natural origin for the RF population. The relationships are given between precedent RF populations (parents) and subsequent RF populations following hybridization (allogamous F2). The allogamous F2 is generally inbred with respect to its parental F1, the degree depending on the hybrid's parents' allele frequencies. At the same time, it is outbred with respect to those original parents, and not inbred at all with respect to the equivalent RF population. The genotypic variance is generally more than in the F1, and likewise for heritabilities. These findings make it possible to evaluate the genetic advance from selection and hybridization. The results depend on the allele frequencies of the original parents and the degree of overdominance, but generally, selection is more advantageous than hybrid vigour.

Scatchard analysis of fluorescent concanavalin A binding to lymphocytes.

Standard Scatchard analysis of ligand binding to cell receptors requires the use of isotopes and is imprecise at low ligand concentrations. To evaluate the feasibility of Scatchard analysis via fluorescence flow cytometry, the binding of fluorescein isothiocyanate-derivatized concanavalin A (FITC-ConA) to murine lymphocytes at 4 degrees C was compared to 125I-ConA binding. A FACS IV flow cytometer (Becton-Dickinson, Mountain View, CA) was used for analysis of cells after fluorescent ligand binding. A simple spectrophotometric technique was used to calibrate the relation between cytometer-determined fluorescence and ligand binding per cell. As FITC-ConA binding showed a quasi-Gaussian distribution, the mean number of molecules bound per cell was easily calculated. Scatchard analysis of FITC-ConA binding yielded results (1.9 x 10(6) receptors/cell, K = 3.6 x 10(-15)) similar to those obtained with 125I-ConA (1.4 x 10(6) receptors/cell, K = 5.2 x 10(-15)). Cytometric Scatchard plots showed less scatter and seemed more precise, suggesting superiority to radioactive ligand measurements, particularly at low ligand concentrations.

Quantitative genetics of intraspecies hybrids.

Quantitative genetics generally is based on the properties of the randomly fertilized (RF) population or inbred derivatives of it. Simple hybrids and hybrid swarms do not conform to this model; and only some properties of hybrid means appear to have been available. In this paper, several genetical properties are derived, including genotype and allele frequencies, genotypic variance, broad-sense heritability, and outbreeding coefficient. The earlier mean is confirmed, and hybrid vigour is examined critically. These results make it possible to evaluate quantitatively both natural selection and forward selection (in plant breeding) from hybrids. An important finding is that hybrids with maximum hybrid vigour do not maximize genetic advance from forward selection, i.e. evolution is unlikely to enhance hybrid vigour. Another finding is that the concepts of additive genetic variance and narrow-sense heritability are inappropriate for hybrids, owing to the genetic disequilibrium inherent from their origin, and to the ephemeral nature of their population structure.

Standard errors of heritabilities for forage breeding nurseries.

Estimators for standard errors of heritability for two typical and complex forage breeding models are illustrated with estimates of variance and covariance components from least-squares and restricted maximum likelihood methods. The first experiment (Model 1) is a factorial design (two grazing management factors) with two layers of split plots (populations and grazing periods) and with plants within populations nested beneath the first split. The second model is for a sites pooling of randomized complete block experiments, with plants nested inside plots and with a split in time. One definition of heritability was applied to the plant habit character for both models in a red clover germplasm. Heritability estimates were statistically the same for the two methods for both models.