Biomedical subjects

A J Anderson

Publications and source records attributed to A J Anderson.

At least 109 records · Page 6Linked to original sources

PubMed1988

Black/white differences in risk factors for arteriographically documented coronary artery disease in men.

Although the leading cause of death among black men in the United States is coronary artery disease (CAD), risk factors have not been well documented in black populations. Therefore, possible racial differences in the relation of several characteristics to the extent of CAD were assessed in 4,722 white and 169 black men who underwent arteriography. Associations between an occlusion score (ranging from 0 to 300), reflecting the severity of CAD, and levels of total and high-density lipoprotein (HDL) cholesterol, triglycerides, cigarette smoking, alcohol intake, relative weight, systemic hypertension and diabetes mellitus were examined. Most risk factors were significantly related to the extent of CAD in both races, but lipid levels showed stronger associations with CAD among blacks: correlations between CAD and total cholesterol were 0.16 (whites) vs 0.29 (blacks) and associations with HDL cholesterol were -0.22 (whites) vs -0.49 (blacks). In addition, at adverse levels of certain risk factors, blacks had more extensive CAD than did whites: mean occlusion scores were 148 (whites) and 238 (blacks) at HDL cholesterol levels less than 30 mg/dl. As assessed by multiple linear regression, however, only triglyceride levels were differentially related to CAD between whites (beta = 0) and blacks (beta = 0.47), p less than 0.01 for racial contrast. These results document the importance of risk factors in black men and indicate black/white differences in the relation of triglycerides to CAD.

Adult↗

PubMed1988

Effects of the facilitatory compounds catechol, guanidine, noradrenaline and phencyclidine on presynaptic currents of mouse motor nerve terminals.

Catechol, guanidine, noradrenaline, and phencyclidine can increase acetylcholine release at neuromuscular junctions. To determine if they act by affecting nerve terminal action potentials, the electrical activity of the terminal regions of motor nerves was recorded with an extracellular electrode inserted in the perineural sheaths of nerves in the mouse triangularis sterni preparation. Catechol (from 10 microM) and guanidine (from 1 mM) produced a selective reduction in the component of the perineural waveform associated with voltage-dependent K+ currents, without significant effects on Na+, Ca2+, or Ca2+-activated K+ currents. A selective block of K+ channels in nerve terminals would cause a prolonged depolarization and hence a large influx of Ca2+ to trigger acetylcholine release; this could explain the facilitatory effects of guanidine and catechol. Noradrenaline produced a slight increase in the amplitude of the perineural waveform. This is consistent with hyperpolarization of the resting membrane potential of the nerve, which could lead to facilitation of acetylcholine release. Phencyclidine blocked Na+- and K+-related portions of the signal.

Animals↗

PubMed1988

Postmenopausal use of estrogen and occlusion of coronary arteries.

The degree of coronary artery occlusion was compared between users and nonusers of postmenopausal estrogen among 933 female patients undergoing angiography between the ages 50 and 75 years in the Milwaukee Cardiovascular Data Registry. Users (n = 154) had less occlusion than nonusers (n = 779), and a significant increase in occlusion scores with age was evident for nonusers (p less than 0.001) but not for users (p = 0.50). The age-adjusted odds ratios for use of postmenopausal estrogen among women with moderate and severe levels of occlusion of the coronary arteries were 0.59 (95% confidence interval, 0.48 to 0.73) and 0.37 (95% confidence interval, 0.29 to 0.46), respectively, which indicated a statistically significant, apparent protective effect of postmenopausal estrogen on coronary occlusion. This effect was independent of the type of menopause or other risk factors but not independent of high-density lipoprotein-cholesterol levels. Higher high-density lipoprotein-cholesterol levels among users may indicate a biologic mechanism by which postmenopausal estrogen use lowers the risk of coronary occlusion.

Aged↗

PubMed1988

Tranquilizer use before and after coronary bypass operation.

High rates of tranquilizer use in coronary disease have been previously reported. In patients being evaluated for coronary disease, tranquilizer use has been related to myocardial infarction, angina pectoris, neurotic traits, employment and the use of cardioactive and other medications. In this study, responses of 1046 male patients to a questionnaire assessing biological, psychological and social variables before and after coronary bypass surgery were related to tranquilizer use. The effect of CABG was to decrease tranquilizer use. Tranquilizer use prior to coronary bypass operations was related to neuroticism, myocardial infarction and taking cardiac and analgesic medication. Similar findings were noted after coronary bypass operations except that angina pectoris was added as a contributor to tranquilizer use. The multivariate analysis tended to confirm the univariate findings, except that neurotic traits did not make an independent contribution. These results indicate that in patients undergoing coronary evaluations, cardiac disease variables other than coronary atherosclerosis determine tranquilizer use. Neurotic traits play a secondary role. Relief of angina pectoris appears to be particularly important in reducing tranquilizer use. The finding of angina pectoris after coronary bypass operation may have special significance for the continuation of tranquilizer use.

Adaptation, Psychological↗

PubMed1988

Diabetes mellitus and arteriographically-documented coronary artery disease.

Diabetics are at increased risk for coronary heart disease even after accounting for other risk factors, and the impact of diabetes mellitus may be particularly strong among females and at adverse levels of other risk factors. Therefore, the independent relation of diabetes to arteriographically-documented coronary artery disease (CAD) was examined in 5620 patients (18% female) referred to two Milwaukee hospitals from 1972 to 1986. As assessed by questionnaire, the prevalence of diabetes mellitus among these patients was 8% (n = 466). Diabetics had increased CAD (assessed by the number and severity of stenoses) even after accounting for levels of total and high-density lipoprotein cholesterol, triglycerides, hypertension, obesity, smoking, and alcohol consumption. In addition, regression analyses indicated that as compared with nondiabetics, female diabetics tended to have a greater increase in CAD than did male diabetics (p = 0.06 for sex x diabetes interaction). Although adverse levels of other risk factors did not increase the association between diabetes and CAD, female diabetics who were using oral hypoglycemics or insulin showed almost a two-fold increase in CAD severity (p less than 0.01). Results suggest that the higher relative risk of coronary heart disease among female (vs male) diabetics may be due to a proportionately greater increase in atherosclerosis.

Adult↗

PubMed1988

Survival and "event-free" analysis of 785 patients with Björk-Shiley spherical-disc valves at 10 to 16 years.

Seven hundred eighty-five patients underwent Björk-Shiley spherical-disc valve replacement from 1970 to 1976. There were 268 mitral valve replacements (MVR), 227 aortic valve replacements (AVR), 65 double-valve replacements, and 225 "combined" procedures. A 97.2% follow-up (mean, 12 years) was achieved. With an operative mortality of 4.1% for MVR, 8.4% for AVR, 15.4% for double-valve replacement, and 12.4% for combined procedures, the 12-year survival was most closely related to age at valve replacement: age less than 50 years, 70%; age 50 through 59 years, 52%; and age 60 years or more, 38%. Twenty-four patients (3.1%) (6 who had MVR, 5 who had AVR, 1 who had double-valve replacement, and 12 who had combined procedures) had a thrombosed valve 1 to 134 months postoperatively; this is equal to 0.36 thrombosed valve per 100 patient-years. One hundred eighteen embolic episodes occurred in 94 (13%) of the operative survivors or 1.8 emboli per 100 patient-years. There were major bleeding complications in 0.5% of patients and minor bleeding complications, in 4.0%. Endocarditis appeared in 30 patients (4.2%) or 0.4 episode per 100 patient-years and paravalvular leaks, in 20 patients (2.8%). The event-free survival by age group and valve site at 5, 10, and 12 years is presented. Events included death, thrombosed valves, strokes, bleeding, emboli, paravalvular leaks, and endocarditis. There were 5.3 events per 100 patient-years excluding operative deaths.

Adult↗

PubMed1988

Results of intraaortic balloon pumping after cardiac surgery: experience with the Percor balloon catheter.

One hundred thirty-eight patients undergoing an open-heart procedure required an intraaortic balloon pump (IAPB) postoperatively. In Group I (N = 45), the AVCO femoral conduit surgical technique was used; in Group II (N = 93), the Percor balloon was inserted either in the operating room after groin cutdown (open insertion) or percutaneously in the intensive care unit (percutaneous insertion). IABP usage increased in Group II (3% versus 1.6%; p less than 0.001). Immediate mortality was 40% (55/138). Use of the Percor balloon in Group II resulted in lower immediate mortality (32/93 or 34% versus 23/45 or 51%; p less than 0.06). Delayed mortality from multiorgan failure was 11.6% (16/138). Immediate percutaneous insertion at the bedside rather than a return to the operating room for open insertion yielded lower mortality (2/8 or 25% versus 6/7 or 86%; p less than 0.05). Open insertion of the Percor balloon decreases the failure rate of insertion compared with both the AVCO femoral conduit technique (7/85 or 8.2% versus 5/45 or 11%) and percutaneous insertion. It has more complications than the AVCO femoral conduit technique (7/85 or 8.2% versus 2/45 or 4.4%) and less than percutaneous insertion.

Adult↗

PubMed1988

Relation of triglyceride levels to coronary artery disease: the Milwaukee Cardiovascular Data Registry.

Although levels of triglycerides have consistently shown a strong association with cardiovascular disease in both case-control and cohort studies, it remains controversial whether this relation exists independently of levels of cholesterol and other risk factors. The association of arteriographically documented coronary artery disease with plasma levels of triglycerides, total cholesterol, and high density lipoprotein (HDL) cholesterol was therefore examined in 5,216 white adults (81% were male) referred to two Milwaukee hospitals between 1972 and 1986. Elevated levels of triglycerides were related to the extent of coronary artery disease (estimated using the total number and severity of stenoses) in both sexes; this association existed independently of total cholesterol, age, obesity, hypertension, smoking, and alcohol consumption. In addition, the association between triglycerides and coronary artery occlusion was strongest at total cholesterol levels less than or equal to 250 mg/dl. However, both stratified and regression analyses indicated there was no residual association between triglyceride levels and occlusion after controlling for HDL cholesterol. (Levels of HDL cholesterol and triglycerides showed a moderate inverse association: r = -0.39 to -0.51.) These results indicate that the association between coronary artery occlusion and levels of triglycerides is indirect, and that the disparate findings of earlier studies may have resulted from not controlling for HDL cholesterol.

Aged↗

PubMed1988

Lipid peroxidation is a consequence of elicitor activity.

Elicitor-active preparations from the fungal pathogen of bean Colletotrichum lindemuthianum stimulated the accumulation of products characteristic of lipid peroxidation in treated bean tissues. Bean suspension cells treated with crude and purified elicitors accumulated ;lipofuscin-like pigment' (LEP) and malondialdehyde. The accumulation of LFP after about 6 h of treatment coincided with the onset of visible browning and production of the bean phytoalexins kievitone, phaseollin, and phaseollinisoflavan. The induction of phytoalexins and accumulation of LFP were also triggered by treatments with generators of activated oxygen species, xanthine:xanthine oxidase and Fe:ethylenediaminedi-o-hydroxyphenylacetic acid. These data suggest that generation of active oxygen species may be involved in lipid peroxidation triggered by elicitors.

Journal Article↗

PubMed1988

Effects of the potassium channel blocking dendrotoxins on acetylcholine release and motor nerve terminal activity.

1. The effects of the K+ channel blocking toxins, the dendrotoxins, on neuromuscular transmission and motor nerve terminal activity were assessed on frog cutaneous pectoris, mouse diaphragm and mouse triangularis sterni nerve-muscle preparations. Endplate potentials (e.p.ps) and miniature e.p.ps were recorded with intracellular microelectrodes, and nerve terminal spikes were recorded with extracellular electrodes placed in the perineural sheaths of motor nerves. 2. Dendrotoxin from green mamba (Dendroaspis angusticeps) venom and toxin I from black mamba (D. polylepis) venom increased the amplitude of e.p.ps by increasing quantal content, and also induced repetitive e.p.ps. 3. Perineural recordings revealed that dendrotoxins could decrease the component of the waveform associated with K+ currents at the nerve terminals, and induce repetitive activation of nerve terminals. 4. In frog motor nerves, dendrotoxins are known to block the fast f1 component of the K+ current at nodes of Ranvier. Blockade of a similar component of the K+ current at motor nerve terminals may be responsible for the effects of these toxins on neuromuscular transmission. 5. Similar conclusions can be drawn from the results obtained from mouse neuromuscular junctions.

Acetylcholine↗

PubMed1988

Effects of charybdotoxin, a blocker of Ca2+-activated K+ channels, on motor nerve terminals.

1. The contribution of Ca2+-activated K+ currents (IK,Ca) to the control of electrical excitability of motor nerve terminals and the control of acetylcholine release was assessed by studying the effects of the specific K(Ca) channel blocking toxins charybdotoxin and apamin. Electrical activity of the terminal regions of motor nerves was assessed by extracellular recording from an electrode placed in the perineural sheaths of nerves in the mouse triangularis sterni and frog cutaneous pectoris preparations. Acetylcholine release was monitored by intracellular recording of endplate potentials (e.p.ps). 2. Charybdotoxin (20-300 nM), but not apamin (10 nM-2.5 microM), selectively reduced the amplitude of an IK,Ca unmasked by prior blockade of the delayed rectifier K+ current with 3,4-diaminopyridine (3,4-DAP). 3. In the combined presence of 3,4-DAP and charybdotoxin, large Ca2+-dependent plateau responses developed, but only moderate and transient increases in acetylcholine release occurred. 4. In the absence of 3,4-DAP, charybdotoxin did not alter the electrical activity of, or the transmitter release from motor nerve terminals. 5. A possible role of the charybdotoxin-sensitive IK,Ca in the control of transmitter release is discussed.

4-Aminopyridine↗

PubMed1988

Molecular Studies on the Role of a Root Surface Agglutinin in Adherence and Colonization by Pseudomonas putida.

Pseudomonas putida aggressively colonizes root surfaces and is agglutinated by a root surface glycoprotein. Mutants of P. putida derived chemically or by Tn5 insertion demonstrated enhanced or decreased agglutinability. Two nonagglutinable Tn5 mutants (Agg) and two mutants with enhanced agglutinability (Agg) possessed Tn5 in unique restriction sites. Agg mutants colonized root surfaces of seedlings grown from inoculated seeds, but at levels lower than those observed with the Agg parent. In short-term binding studies, Agg cells adhered at levels that were 20- to 30-fold less than those for Agg parental cells. These data suggest that the agglutination interaction plays a role in the attachment of P. putida to root surfaces.

Journal Article↗

PubMed1988

Fusarium Wilt Suppression and Agglutinability of Pseudomonas putida.

Mutants of Pseudomonas putida (Agg) that lack the ability to agglutinate with components present in washes of bean and cucumber roots showed limited potential to protect cucumber plants against Fusarium oxysporum f. sp. cucumerinum. However, a higher level of protection was observed against Fusarium wilt in cucumber plants coinoculated with the parental bacterium (Agg), which was agglutinable. The Agg mutants did not colonize the roots of cucumber plants as extensively as the Agg parental isolate did. In competition experiments involving bean roots inoculated with a mixture of Agg and Agg bacteria, the Agg strains colonized roots to a greater extent than the Agg cells did. These data suggest that the Agg phenotype provides additional interactions that aid in the beneficial character of P. putida.

Journal Article↗

PubMed1988

Chest pain and behavior in suspected coronary artery disease.

This study assessed behavioral activity, dietary and emotional variables among patient cohorts with angina pectoris, atypical chest pain, and no chest pain in whom coronary disease is suspected. Questionnaire responses of 3,899 employed male patients at the time of coronary arteriography were analyzed. Patients with angina pectoris had high levels of coronary-prone and neurotic attitudes, and fatigue variables including feeling unrested on awakening, easy fatiguability, reducing activity at work and arriving home tired. Atypical chest pain patients showed coronary-prone and neurotic attitudes similar to the angina pectoris group but had less coronary occlusion and lower levels of fatigue variables. Compared to the other groups, atypical chest pain patients were more likely to skip breakfast and showed a trend to eat fast. These findings suggest that including assessment of activity levels, fatiguability, eating behavior, neurotic traits and coronary-prone attitudes at time of coronary arteriography can have some limited value for patients with chest pain who may seek cardiac treatment but could benefit from alternative approaches.

Angina Pectoris↗

PubMed1987

Omega-conotoxin does not block the verapamil-sensitive calcium channels at mouse motor nerve terminals.

Release of acetylcholine at the neuromuscular junctions of skeletal muscle is not sensitive to organic Ca2+ channel blockers. However, in mouse motor nerve endings, extracellular recording reveals that a verapamil-sensitive Ca2+ current can be induced after block of K+ channels. Recordings of extracellular action potentials from inside the perineural sheaths of nerves innervating mouse triangularis sterni muscles reveal that this verapamil-sensitive current is not blocked by omega-conotoxin, and hence, it does not involve channels similar to the L-channels of neuronal cell bodies.

Animals↗

PubMed1987

The Effect of Extracellular Components from Colletotrichum lindemuthianum on Membrane Transport in Vesicles Isolated from Bean Hypocotyl.

Extracellular components released from mycelia of the alpha and beta races of the bean pathogen, Colletotrichum lindemuthianum, inhibited proton uptake in sealed vesicles prepared from bean hypocotyls. Differential sensitivity of ATP-driven proton transport to nitrate, vanadate, N,N'-dicyclohexylcarbodiimide, diethylstilbestrol, and oligomycin suggested the vesicles were enriched for tonoplast. Anion stimulation of proton transport, by enhancement of ATPase activity and dissipation of the membrane potential, was consistent with this conclusion. Although fungal components inhibited the formation of a pH gradient, the membrane potential was unaffected and the ATPase activity slightly stimulated. These data suggest that the fungal components produce an electroneutral proton exchange. Proton transport in Dark Red Kidney bean tonoplast vesicles was inhibited by mycelial preparations from the incompatible alpha race and compatible beta race. Elicitor activity, however, was greater in the alpha race fractions. Elicitor purified from alpha race culture filtrate did not inhibit proton transport in vesicles isolated from Dark Red Kidney bean. Consequently, elicitor activity need not be associated with an ability to impair tonoplast function.

Journal Article↗

PubMed1987

The Effect of Pseudomonas putida Colonization on Root Surface Peroxidase.

Increased activities of peroxidase and indole 3-acetic acid (IAA) oxidase were detected on root surfaces of bean (Phaseolus vulgaris) seedlings colonized with a soil saprophytic bacterium, Pseudomonas putida. IAA oxidase activity increased over 250-fold and peroxidase 8-fold. Enhancement was greater for 6-day-old than for 4- or 8-day-old inoculated plants No IAA oxidase or peroxidase activities were associated with the bacterial cells. Native polyacrylamide gel electrophoresis demonstrated that washes of P. putida-inoculated roots contained two zones of peroxidase activity. Only the more anodic bands were detected in washes from noninoculated roots. Ion exchange and molecular sizing gel chromatography of washes from P. putida-colonized roots separated two fractions of peroxidase activity. One fraction corresponded to the anodic bands detected in washes of P. putida inoculated and in noninoculated roots. A second fraction corresponded to the less anodic zone of peroxidase, which was characteristic of P. putida-inoculated plants. This peroxidase had a higher IAA oxidase to peroxidase ratio than the more anodic, common enzyme. The changes in root surface peroxidases caused by colonization by a saprophytic bacterium are discussed with reference to plant-pathogen interactions.

Journal Article↗

PubMed1987

Comparison of the Milwaukee Neurotic Trait Screening Scale with the Symptom Check List.

Responses from 45 volunteers to the Milwaukee Neurotic Trait Scale (NT) and to the Hopkins Symptom Check List (SCL-90R) were compared. The NT scale was significantly correlated with the subscales of the SCL-90R. Second, agreement for high, middle, and low scores was found between the NT Scale and the SCL-90R Global Severity Index and Positive Symptom Total. These limited findings, based on a small sample of students, are promising and warrant replication with different and larger groups of adults.

Adult↗