Psychological traits and serum lipids. I. Findings from the California Psychological Inventory.
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Biomedical subjects
Publications and source records attributed to M Friedman.
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Urinary excretion of testosterone glucuronide was compared in 13 men with typical Type A behavior pattern (as determined by structured interviews) and 10 age-matched men with typical Type B behavior pattern. Twenty-four hour urine collections were divided into three periods: 9AM - 6PM , 6PM to bedtime, and bedtime to 9AM . Type A men showed a significantly higher excretion than Type B men in the daytime ( 9AM - 6PM ); the geometric mean value was 24 micrograms in Type A and 15 micrograms in Type B (P less than 0.05). There were no significant differences between Type A and Type B men for the other two time periods. Indicating an elevated daytime testosterone secretion in Type A men, this finding is consistent with a recent report that exposure to laboratory tests of reaction time causes an increase in plasma testosterone levels in Type A but not Type B men. Since a role for testosterone in the genesis of coronary heart disease (CHD) is suggested by the much higher incidence of CHD in men and the acceleration of murine atherogenesis by testosterone, the findings of this and the previous report may represent a mechanism for the elevated incidence of CHD in Type A men.
The feasibility of altering a Type A style of life was investigated in 1012 nonsmoking predominantly male postinfarction volunteers in the San Francisco Bay area. A total of 862 were randomly allocated into an experimental section receiving a combination of Type A and cardiac counseling, or a control section receiving cardiac counseling alone. The remaining 150 formed a nonrandom but statistically equivalent comparison section. Assessments of change in Type A behavior were made by the participant, his or her spouse, a work colleague, and an independent rater of a videotaped structured interview. Psychometric analyses indicated that these instruments were valid and reliable measures of Type A behavior. After 24 months, participants receiving Type A/cardiac counseling exhibited a significantly greater reduction in Type A behavior than the other two sections, and had a lower cardiovascular recurrence rate than the comparison section only. No differences among the three sections were observed in total cholesterol or resting blood pressure. The results suggest that Type A behavior can be altered by group counseling in postinfarction volunteers and that such alteration is superior to no group counseling at all in the secondary prevention of coronary heart disease.
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Dental caries is a chronic infectious disease caused by the accumulation of bacterial plaque (biofilm) on tooth surfaces. Antibacterial agents, in addition to other preventive measures, can control dental plaque accumulation. Amine fluorides (AmF) are known anticaries agents for over 30 years. The purpose of our study was to assess the adsorption and desorption of AmF to experimental dental biofilm and to evaluate the effect of AmF on Streptococcus sobrinus 6715 and glucosyltransferase (GTF) activity in experimental dental biofilms. The experimental plaque model used in this study consists of hydroxyapatite beads coated with human saliva (sHA), followed by adsorption of S. sobrinus and synthesis of in situ polysaccharides. Our results show that the viability of S. sobrinus in biofilm decreased as the concentration of AmF and chlorhexidine (CHX) increased. The concentration of AmF and CHX required to kill S. sobrinus adherent to sHA is about 100 times greater than the concentration required to kill the same amount of planktonic bacteria. Adsorption of AmF to surfaces was more than 90% and the desorption of AmF from our experimental model was limited. Pre-adsorption of AmF on the surface increased adhesion of S. sobrinus but also resulted in surface killing of the adsorbed bacteria. At low concentrations AmF increased GTF activity in solution by about 10%, but at concentrations above 0.1 mM it inhibited GTF activity. Inhibition of GTF on the surface required about 100 times more AmF than in solution. Our results show that AmF retains its anticariogenic effects in solution and in biofilm systems.
This study describes properties of potential sustained release varnishes (SRV) containing amine fluoride or amine fluoride with stannous fluoride. The release kinetics, antibacterial properties and antiadhesion properties of two potential varnishes were tested. The varnish of ethylcellulose matrix was found to release fluoride for 4 h in vitro, while the formulation based on hydroxypropylmethylcellulose acetate succinate had a rapid release rate. Hydroxyapatite tablets coated with ethylcellulose-based SRV increased adhesion of Streptococcus mutans, while tablets coated with hydroxypropylmethylcellulose acetate succinate-based SRV decreased bacterial adhesion. Both types of SRV demonstrated a strong antibacterial effect on bacteria in biofilm.
Laryngeal complications secondary to nasogastric intubation have been reported rarely in recent literature. Recent experience with three patients who developed laryngeal injuries related to nasogastric tubes prompted retrospective, experimental, and prospective studies to determine the mechanism of laryngeal injury. A review of the literature, as well as the clinical findings in our three patients, point to midline tube placement and the subsequent development of cricoid chondritis as the underlying etiology. An experimental study using anesthetized dogs was designed to compare histologically the effect on the larynx with nasogastric tubes placed in the midline, as opposed to nasogastric tubes in the lateral position. Results of the histologic study confirmed that midline tubes generate severe inflammation in the postcricoid region. One hundred patients were then evaluated roentgenographically to determine the incidence of midline tube placement in a random sample. Six percent of the patients had nasogastric tubes in the midline. Patients who have nasogastric tubes in place for more than three days or have a severe amount of discomfort should have an x-ray film to determine position of the tube. Midline tubes should be removed or replaced.
Reconstruction of the subglottis is usually required after resection of cricoid cartilage or tracheal tissue in cases of trauma, subglottic stenosis, or invasive thyroid carcinoma. There are multiple techniques available for reconstruction of the subglottic larynx, but most of them have a high rate of complications or graft failure. We have found the sternocleidomastoid myoperiosteal flap to be an ideal means of reconstruction. In an experimental study, we performed subglottic reconstruction using the sternomastoid myoperiosteal flap on 15 mongrel dogs to determine the presence of bone formation versus calcified fibrous scar. Radiologic studies suggested apparent metaplastic bone formation at the graft site, and histologic studies confirmed this. Functionally, 12 dogs had stable airways without stridor or subglottic narrowing. Three dogs died of complications. With successful reconstruction of large defects in the canine subglottis, attempts to repair large subglottic and tracheal defects in the human are feasible.
Spastic dysphonia is a disorder characterized by strained, constricted phonation with excessively adducted vocal cords. Despite initial success with recurrent laryngeal nerve section, the search for other treatment continues. Our clinical study involved inserting a needle electrode percutaneously into the region of the recurrent laryngeal nerve in five patients with spastic dysphonia. Electrical stimulation resulted in dramatic improvement in three patients and minimal improvement in two. Our experimental study was designed to create an animal model for an implantable nerve stimulator to be used on a long-term basis. A Medtronic spinal cord stimulation system was implanted into a dog, and a cuff electrode was positioned around the recurrent laryngeal nerve. Vocal cord position could be altered by varying the stimulus frequency. Long-term stimulation of the recurrent laryngeal nerve was relatively safe and effective. Eventually, we plan to implant nerve stimulators into spastic dysphonia patients who respond well to percutaneous stimulation.
The model given in this report and the rotating disk method provide a useful combination in the study of dental enamel and hydroxyapatite dissolution kinetics. The present approach is a significant improvement over earlier studies, and both the ionic activity product that governs the dissolution reaction and the apparent surface dissolution reaction rate constant may be simultaneously obtained. Thus, these investigations have established the baseline for the dissolution rate studies under sink conditions. Concurrent studies, under conditions where the acidic buffer mediums are partially saturated with respect to hydroxyapatite have shown another dissolution site for hydroxyapatite that operates at a higher ionic activity product but has a much smaller apparent surface reaction rate constant. This has raised the question of whether the presence of this second site may interfere with the proper theoretical analysis of the experimental results obtained under sink conditions. A preliminary analysis of the two-site model has shown that the dissolution kinetics of hydroxyapatite under sink conditions is almost completely governed by the sink condition site (KHAP = 10(-124.5), k' = 174) established in this report. The difference between the predicted dissolution rate for the one-site model and the two-site model are generally of the order of 4 to 5% where the experiments are conducted under sink conditions and over the range of variables covered in the present study.
The efficacy of dihydropyridine calcium channel blockers for treating hypertension appears to be similar, but a variety of factors, including patient characteristics, tolerability and pharmacokinetic properties, may influence treatment adherence and outcome. We aimed to evaluate treatment adherence in clinical practice among older hypertensive adults (50+ years) prescribed amlodipine or felodipine for the first time as part of the California Medicaid (Medi-Cal) program. We used a retrospective, matched, cohort-analysis design. Over 1 year, patients prescribed amlodipine were 21% less likely to discontinue study treatment than those prescribed felodipine. Discontinuation tended to occur early, with 20% and 30% of amlodipine and felodipine patients, respectively, discontinuing treatment after one prescription. A non-significant difference in favour of amlodipine was demonstrated for anti-anginal medication use among patients taking these drugs at baseline. This study suggests that use of amlodipine may be associated with improved adherence, compared with felodipine, among older out-patients in the Medi-Cal program.
Endoscopic frontal sinus surgery, once the last frontier in the evolution of endoscopic sinus surgery, is considered difficult, risky to the patient, and likely to result in a high failure rate. We clarify the surgical anatomy for frontal sinus surgery that, based on a review of our data, provides safe and predictable access to the frontal sinus. We studied 200 consecutive patients with respect to indications, endoscopic and radiographic findings, results, and complications. The study will describe the technique in detail, including the following points: 1) computed tomography identification of the superior attachment of the uncinate process; 2) complete removal of the uncinate process, including its superior attachments, by using the microdebrider; 3) removal of the agger nasi cell, if present; and 4) verification of an open frontal sinus by a transillumination or image-guided system. Postoperative assessment of patients' symptoms and the confirmation of a patent frontal sinus by office endoscopy and transillumination indicated a 90% patency for short-term follow-up (average 12.2 months). There were no major complications. Postoperative complications included frontal recess stenosis, polypoid mucosa occluding the frontal recess, and middle turbinate lateralization. All of these situations may lead to recurrence of infection and symptoms. In-depth understanding of anatomic variations of the uncinate process and precise surgical removal of its superior attachments provide surgical access to the frontal sinus that is based on the natural ostia and is, therefore, more likely to remain patent.
Rat alveolar macrophages were prelabeled with 3H-arachidonic acid (3H-AA) and exposed to air or O3 (0.1-1.0 ppm) in vitro for 2 h. Alveolar macrophages released 3.6-fold more tritium at the 1.0 ppm exposure concentration compared with air-exposed macrophages. A significantly increased production of several 3H-AA metabolites, including 6-keto-PGF1 alpha, thromboxane B2, 12-hydroxy-5,8,10-heptadecatrienoic acid, prostaglandins E2 and D2, leukotrienes B4 and D4, and 15-hydroxyeicosatetraenoic acid was formed by macrophages exposed to 1.0 ppm O3 compared with air-exposed macrophages as determined by high performance liquid chromatography (HPLC) analysis. O3 exposure did not alter macrophage 3H-AA metabolism in response to calcium ionophore A23187. The largest tritiated peak observed in the HPLC chromatograms of O3-exposed cells was a polar complex of products that contained various phospholipids and neutral lipids (including diacylglycerol) and possibly degradation products of 3H-AA and some of its metabolites. These changes in macrophage arachidonic acid metabolism may play an important role in the lung response to O3 exposure in vivo.
The effects of tumor necrosis factor alpha (TNF alpha) and platelet-activating factor (PAF) on monolayer permeability, cytotoxicity, and release of prostacyclin (measured as the stable metabolite 6-ketoprostaglandin [PG]F1 alpha) and thromboxane (TX)B2 were investigated in bovine pulmonary artery endothelial cells (BPAEC). After 4 h of incubation, TNF alpha (2000 U/mL) induced an increase in steady-state 125I-albumin permeability across the BPAEC monolayer (2.9 +/- 0.3%/h vs. 1.8 +/- 0.3%/h in control monolayers; n = 7, p < .05), and induced release of 6-keto-PGF1 alpha (2581 +/- 226 pg/mL vs. 863 +/- 164 pg/mL in controls; n = 16, p < .05) and TXB2 (204 +/- 14 pg/mL vs. 105 +/- 23 pg/mL in controls; n = 10, p < .05). PAF-incubation was also associated with increased 6-keto-PGF1 alpha and TXB2 release (4157 +/- 471 pg/mL and 276 +/- 32 pg/mL, respectively), but did not markedly alter morphology or increase 125I-albumin permeability. Specific tritiated deoxyglucose release and specific LDH release were unaffected by both treatments. These results indicate that TNF alpha contributed directly to increased BPAEC permeability without cytotoxicity or requirement for other serum or cellular components. However, PAF did not directly alter endothelial barrier function despite increased release of 6-keto-PGF1 alpha and TXB2.
Bleomycin (BLM) induction of lung fibrosis in mice is an established model to study the mechanism of pulmonary fibrosis. Cytokine secretion has been implicated as a fundamental component of the lung fibrotic process observed in response to BLM. Among the cytokines implicated in lung fibrosis, Tumor necrosis factor (TNF) alpha has been considered to play a fundamental role. In the present study, we characterized the cellular sources of TNF during BLM-induced lung injury and examined the importance of TNF receptors in this process. To characterize the expression of TNF, we utilized two strains of mice, one sensitive (C57BL/6) and one resistant (BALB/c) to BLM-induced lung injury. Mice received BLM (120 mg/kg total) or saline, as control, by multiple subcutaneous injections. BLM induced the development of inflammation in subpleural areas only in the lungs of BLM-sensitive mice. These subpleural areas were characterized by infiltration of CD68-positive macrophages and increased collagen deposition. BLM enhanced the expression of TNF mRNA in BLM-sensitive, but not in BLM-resistant, mice. In situ hybridization studies localized the expression of TNF in the areas of BLM-induced inflammation in 6% and 27% of macrophages at 14 and 21 days post BLM treatment. In addition to TNF, BLM exposure resulted in the upregulated expression of transforming growth factor (TGF)-beta 1, but not interleukin (IL)-1, mRNA in the lungs of both murine strains at 14 and 21 days. This upregulated expression of TGF-beta 1 mRNA was greater in the lungs of BLM-sensitive mice. In separate experiments, double TNF receptor knockout mice were exposed to BLM. These animals demonstrated an increased expression of TNF, but not TGF-beta 1, mRNA in response to BLM and did not exhibit histologic evidence of lung injury following BLM exposure. In summary, the upregulation of TNF mRNA in macrophages correlated with the appearance of inflammation following BLM exposure and was limited to the BLM-sensitive strain. Furthermore, in addition to the release of the TNF ligand, it appears that the presence of TNF receptors is necessary for the development of BLM-induced lung injury, and signaling through these receptors may contribute to the regulation of the TGF-beta 1 mRNA expression observed in response to bleomycin. These results provide further support for a role of macrophages and TNF in the induction of lung inflammation.
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CONTEXT: The Medicare program is encouraging its beneficiaries to enroll in capitated health plans. OBJECTIVE: To determine how prepared these plans are to handle chronically ill and frail elderly persons. DESIGN: Telephone survey of 28 health plans that together serve about one fourth of all enrollees of the Medicare Risk program. MEASURES: The degree of readiness (high, intermediate, or low) of health plans in seven domains that experts believe are important to the management of an elderly population. RESULTS: None of the 28 health plans had high readiness scores for all seven domains. The two domains for which the plans were most prepared were risk assessment and member self-care. The plans were least prepared for the domains of cooperative team care and geriatric consultations. CONCLUSIONS: Many plans do not offer the programs that experts believe are important for Medicare enrollees. They may hesitate to adopt strategies that lack data on effectiveness.