PubMed Health⌕ Search

Biomedical subjects

H Peterson

Publications and source records attributed to H Peterson.

At least 19 recordsLinked to original sources
PubMed1998

Psychotherapy in primary care: the BATHE technique.

The family physician occupies a front-line position in the detection and treatment of emotional problems and psychiatric illnesses. The practice pattern of the family physician necessitates an efficient, effective model of psychotherapy The BATHE technique is a brief psychotherapeutic method that addresses the patient's background issues, affect and most troubling problem. The emphasis of the interview then shifts to how the patient is handling the problem and a demonstration of empathy by the physician. Some of the challenges in psychotherapy are presented, and cases in which the BATHE technique was used are described.

Humans↗
PubMed1998

Arterial injury by cholesterol oxidation products causes endothelial dysfunction and arterial wall cholesterol accumulation.

Cholesterol oxidation products (ChOx) have been reported to cause acute vascular injury in vivo; however, the pharmacokinetics of ChOx after administration and the mechanisms by which they cause chronic vascular injury are not well understood. To further study the pharmacokinetics and atherogenic properties of ChOx, New Zealand White rabbits were injected intravenously (70 mg per injection, 20 injections per animal) with a ChOx mixture having a composition similar to that found in vivo during a 70-day period. Total ChOx concentrations in plasma peaked almost immediately after a single injection, declined rapidly, and returned to preinjection levels in 2 hours. After multiple injections, the ChOx concentrations rose gradually to levels 2- to 3-fold above baseline levels, increasing mostly in the cholesteryl ester fraction of LDL and VLDL. Rabbit serum and the isolated LDL/VLDL fraction containing elevated ChOx concentrations were cytotoxic to V79 fibroblasts and rabbit aortic endothelial cells. At the time of killing, cholesterol levels in the aortas from ChOx-injected rabbits were significantly elevated despite the fact that plasma cholesterol levels remained in the normal range. In addition, aortas from the ChOx-injected rabbits retained more 125I-labeled horseradish peroxidase, measured 20 minutes after intravenous injection. Transmural concentration profiles across the arterial wall also showed increased horseradish peroxidase accumulation in the inner half of the media from the thoracic aorta in ChOx-injected rabbits. In conclusion, ChOx injection resulted in accumulation of circulating ChOx and induced increased vascular permeability and accumulation of lipids and macromolecules. This study reveals that even under normocholesterolemic conditions, ChOx can cause endothelial dysfunction, increased macromolecular permeability, and increased cholesterol accumulation, parameters believed to be involved in the development of early atherosclerotic lesions.

Animals↗
PubMed1997

Correlation between self-reported cocaine use and urine toxicology in an inner-city prenatal population.

To determine the prevalence of recent cocaine use and the accuracy of self-reported use, the results of a urine assay for the major cocaine metabolite benzoylecgonine were compared with self-reported cocaine use in an inner-city prenatal population offered routine voluntary urine toxicology screening at the time of registration for prenatal care. During a 1-year period, 6866 women registered for prenatal care and 5200 (76%) consented to urine assays for cocaine metabolites. Of the women consenting to urine assays, 253 (5%) had positive assays for benzoylecgonine. Women with positive assays were significantly more likely than those with negative assays to be older (mean [SD] 27 [5] versus 23 [6] years), black, single, and unemployed. In addition, women with positive assays were significantly more likely to be multiparous, report > two sexual partners in the previous year, and acknowledge a history of a sexually transmitted disease (STD). Forty-seven percent of women with positive assays acknowledged cocaine use in the 6 months prior to sampling. Women with positive assays who denied cocaine use were significantly more likely than those who admitted use to be younger (mean [SD] 26 [5] versus 28 [4] years), to report > or = two sexual partners in the past year, and acknowledge a history of an STD. This analysis revealed a poor correlation between self-reported cocaine use and the results of urine assays for cocaine metabolites among women seeking prenatal care in an inner-city institution.

Cocaine↗
PubMed1996

Factors affecting medical students' selection of Canadian psychiatric residency programs: Part I--A comparison with American peers.

OBJECTIVE: The introduction of a national process to match Canadian medical students to postgraduate year-one (PGY-1) positions in psychiatry created for the first time a cohort of subjects whose choices of a particular training program could be evaluated and compared with American peers. The primary goal of this study was to determine the factors affecting the students' selection of the specific postgraduate programs in which they would train and to compare the findings with those in the American literature. METHOD: A self-administered questionnaire was sent to 110 trainees who began training in July 1994 identified in the 16 Canadian university departments of psychiatry. RESULTS: Canadian trainees, like their American counterparts, relied heavily on nonprogrammatic factors in program choice, but differed in emphasizing vocational prospects after residency. CONCLUSION: When competing for enrollment within a reduced pool of applicants, program directors need to recognize how programs are evaluated, what factors are controllable, and how best to market the individual assets of their programs.

Adult↗
PubMed1996

Factors affecting medical students' selection of Canadian psychiatric residency programs: Part II-Some contemporary issues.

OBJECTIVE: The presence of a national cohort of trainees entering psychiatric residency allowed an assessment of contemporary factors influencing their particular program choices. Factors of specific interest included the effect on program choice of relationships with significant others and government attitudes to fiscal restraint, mental health care reform, and licensure. METHOD: A self-administered questionnaire was sent to 110 trainees identified in the 16 Canadian university departments of psychiatry who began training in July 1994. RESULTS: While a committed relationship was a primary determinant of program choice, government policies attempting to influence patterns of care had little effect. CONCLUSION: A strong commitment to undergraduate teaching will improve the attractiveness of psychiatry as a career. This must include exposure of students to teachers who mentor practice patterns attuned to provincial mental health reforms, since government initiatives alone, developed to promote desired transitions in psychiatric care, will not influence training program choice.

Adult↗
PubMed1995

Effect of linoleic acid hydroperoxide on endothelial cell calcium homeostasis and phospholipid hydrolysis.

The relationship between intracellular free calcium ion concentrations ([Ca2+]i) and release of arachidonic acid from membrane phospholipids following peroxidation was examined in rabbit aortic endothelial cells treated with linoleic acid hydroperoxide (LOOH). LOOH (0.1-0.4) mumol/10(6) cells) caused a rapid and dose-dependent transient increase in [Ca2+]i in the presence of extracellular Ca2+ that remained elevated over baseline for 15 to 30 s. In the absence of extracellular Ca2+, LOOH also evoked a transient increase in [Ca2+]i of lesser magnitude which immediately returned to basal (or below basal) levels. In this regard, the rise in intracellular Ca2+ after LOOH or vasopressin (AVP) treatments involved, at least in part, related intracellular pools that in each case was followed by influx of extracellular Ca2+. The intracellular membrane sources known to be affected by vasopressin were not directly involved. Most notably, the LOOH evoked rise in [Ca2+]i was not associated with release of IP3, suggesting that the source of intracellular Ca2+ is not IP3-sensitive pools. However, pretreatment with LOOH strongly inhibited the rise in [Ca2+]i upon subsequent addition of AVP or LOOH and the extent of such inhibition was dependent on the availability of free intracellular Ca2+ and presence of extracellular Ca2+. These findings suggest that reuptake of Ca2+ into intracellular membrane pools is reduced in the presence of LOOH and/or the availability of Ca2+ from agonist-sensitive sites is inhibited by LOOH. An increase in free 20:4 levels was found after LOOH treatment that was only partly prevented using intracellular Ca2+ chelators which maintained [Ca2+]i at basal levels after LOOH treatment. These findings suggest that LOOH induction of phospholipid hydrolysis proceeds following small transients in [Ca2+]i that are considerably less than that evoked by agents such as AVP, approximating basal Ca2+ concentrations. Inhibition of LOOH-induced lipid peroxidation by vitamin E also prevented the rise in [Ca2+]i and 20:4 release indicating that phospholipid hydrolysis is dependent, at least in part, on membrane lipid peroxidation. Inhibition of protein kinase C (PKC) completely blocked LOOH-induced release of 20:4 but had little effect on the LOOH-induced rise in [Ca2+]i, suggesting an indirect relationship between LOOH-induced membrane Ca2+ signalling events, with intervention via PKC-mediated induction of phospholipid hydrolysis. A rapid and progressive translocation of PKC to the membrane fraction was evident after LOOH addition over the time course corresponding to the maximal release of 20:4 which was also inhibited by vitamin E.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Characterization of endothelial cell injury by cholesterol oxidation products found in oxidized LDL.

The present study describes the toxicity of oxidized LDL towards rabbit aortic endothelial cells in terms of its lipid components with specific attention to the cholesterol oxidation products (ChOx) found in oxidized LDL isolated from human plasma. Measurements of the major ChOx associated with freshly isolated unmodified LDL, those found in oxidized LDL isolated from human plasma and LDL subjected to oxidation in vitro are described. We have confirmed previous findings that most of the cytotoxicity of freshly isolated human LDL may be attributable to a minor fraction that appears to be oxidatively modified by several criteria. Moreover, this plasma-derived oxidized LDL (referred to as LDL) is highly enriched in ChOx, whereas the content of lipid peroxides or derived products (measured as conjugated dienes and thiobarbituric acid reacting products) are much lower, particularly when compared to copper-induced LDL oxidation. Much of the ChOx found in plasma are associated with LDL, however, the levels and proportions of the various ChOx found in LDL differ from those produced after extensive copper-induced oxidation but resemble those produced after moderate oxidation with copper. The species and concentrations of ChOx found in LDL when applied as a mixture exhibit considerably more toxicity than any individual ChOx alone. At non-toxic levels this ChOx mixture causes an increased influx of several ions, including calcium, an effect not seen with individual ChOx at comparable doses. Perturbations in ionic homeostasis, and particularly the sustained increase in intracellular calcium concentrations, are associated with much of the cytotoxicity, an effect attributable to the membrane disruptive action of ChOx leading to altered ion transporter activity. The effect of the ChOx mixture (but not any individual ChOx) on sodium and potassium flux appears to be due to enhanced Na+/K(+)-ATPase activity based on the complete inhibition produced by ouabain under all treatment conditions. These findings also show that the levels of cholesterol oxidation products found in normal LDL are not cytotoxic whereas those present in oxidized LDL exceed the toxic threshold for endothelial cells and account for most of the cytotoxicity produced by this modified lipoprotein.

Animals↗
PubMed1994

Linoleic acid hydroperoxide-induced peroxidation of endothelial cell phospholipids and cytotoxicity.

Peroxidation of endothelial cell phospholipids was examined following treatments with linoleic acid hydroperoxide. The treatment effects were analyzed over a range of toxicities and exposure intervals as determined by cell plating efficiencies and survival. Over the concentration ranges where lipid peroxidation was evident (20-40 microM treatments in complete medium), significant cytotoxicity was apparent after 1 h of exposure. The extent of toxicity was dependent on the time interval between the end of peroxide treatment and replating of cells. Maximum toxicity was found when cells were replated 1-3 h after treatment. When cells were replated 4 h after treatment a linear increase in cell survival was found as a function of replating time following peroxide exposure. Analysis of cell phospholipids by HPLC after 1 h of exposure to linoleic acid hydroperoxide revealed that peroxidation (evidenced by conjugated diene content) had taken place among a number of phospholipid species with the most marked increases in phosphatidylcholine. Analysis of the fatty acyl composition of phospholipids also showed that the proportions of polyunsaturated fatty acids were reduced relative to saturated fatty acids, indicating peroxidative damage to phospholipids. Pretreatment of cells with vitamin E prevented the peroxidation of all phospholipids and blocked the cytotoxic action of linoleic acid hydroperoxide. These findings indicate that an immediate cytotoxic action of lipid hydroperoxide is associated with peroxidation of membrane phospholipids. This cytotoxicity is a transient effect, and cells surviving the acute injury display a time-dependent increase in plating efficiency representing a period of repair.

Animals↗
PubMed1994

A prospective cohort study on breast-feeding and otitis media in Swedish infants.

This study analyzed the effect of breast-feeding on the frequency of acute otitis media. The protocol was designed to examine each child at 2, 6 and 10 months of age. At each visit nasopharyngeal cultures were obtained, the feeding pattern was recorded and the acute otitis media (AOM) episodes were documented. The analysis was based on 400 children from whom complete information was obtained. They represented 83% of the newborns in the study areas. By 1 year of age 85 (21%) children had experienced 111 AOM episodes; 63 (16%) had 1 and 22 (6%) had 2 or more episodes. The AOM frequency was significantly lower in the breast-fed than in the non-breast-fed children in each age group (P < 0.05). The first AOM episode occurred significantly earlier in children who were weaned before 6 months of age than in the remaining groups. The frequency of nasopharyngeal cultures positive for Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae was significantly higher in children with AOM. At 4 to 7 and 8 to 12 months of age, the AOM frequency was significantly higher in children with day-care contact and siblings (P < 0.05 and < 0.01, respectively). The frequency of upper respiratory tract infections was increased in children with AOM but significantly reduced in the breast-fed group.

Acute Disease↗
PubMed1994

Biochemical and cytotoxic characteristics of an in vivo circulating oxidized low density lipoprotein (LDL-).

Using ion exchange high pressure liquid chromatography, total plasma low density lipoprotein (LDL) from 30 hypercholesterolemic and 10 normocholesterolemic cynomolgus monkeys was subfractionated into unmodified LDL (n-LDL) and more negatively charged LDL (LDL-). In hypercholesterolemic monkeys, the absolute LDL-cholesterol level was 16.54 +/- 2.82 mg/dl (mean +/- SE) whereas in normocholesterolemic monkeys it was 2.39 +/- 0.12 mg/dl (P < 0.0001); the percentage of LDL- was 5.2 +/- 0.71% and 4.9 +/- 0.19% of the total LDL for hypercholesterolemic versus normocholesterolemic monkeys, respectively. LDL- averaged 5% and n-LDL 95% of the total plasma LDL cholesterol. To confirm and further elucidate the oxidative nature of LDL-, cholesterol and cholesterol oxide contents of LDL- and n-LDL were determined by capillary gas chromatography; 53.98 +/- 2.24% (mean +/- SE) of the LDL- cholesterol was oxidized whereas in n-LDL only 10.70 +/- 1.06% of the cholesterol was oxidized (P < 0.00001). The spectrum of oxysterols identified, which was similar for LDL- and n-LDL, suggested a free radical-mediated process for cholesterol oxidation. The principal oxysterols identified were: cholest-5-ene-3 beta, 7 alpha-diol, cholesta-3,5-diene-7-one, cholest-5-ene-3 beta, 7 beta-diol, 5,6 beta-epoxy-5 beta-cholestan-3 beta-ol, 5,6 alpha-epoxy-5 alpha-cholestan-3 beta-ol, 5 alpha-cholestan-3 beta,5,6 beta-triol, 3 beta-hydroxycholest-5-ene-7-one, and cholest-5-ene-3 beta,25-diol. To model one of the steps in the possible mechanism of atherogenesis, the cytotoxicity of LDL- was demonstrated to be greater against subconfluent than confluent aortic endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Quality of life measures for patients receiving adjuvant therapy for breast cancer: an international trial. The International Breast Cancer Study Group.

Serial quality of life (QL) assessments are being obtained every 3 months for 2 years from patients with operable breast cancer in two ongoing International Breast Cancer Study Group (IBCSG) randomised clinical trials of adjuvant treatment. The QL-assessments include patient-derived perceived coping (PACIS, personal adjustment to chronic illness scale), well-being (Bf-S, Befindlichkeitsskala von Zerssen), mood, physical well-being and appetite (LASA, linear analogue self assessments). The first assessment within 6 weeks of surgery was performed by 70% of the patients. The analysis of serial assessments for 265 patients with each of the first four assessments completed showed that all measures improved with increasing time from study entry; that the degrees of improvement for the four major language groups were similar; and that measures were sensitive to treatment difference. In conclusion, measurement of QL related aspects in a multicultural clinical trial is feasible and possibly relevant for the evaluation of treatment results.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Eldercare: more than company kindness.

Employees caring for aging family members could be costing your company money. Eldercare benefits could be the solution. Relatively inexpensive programs can make a difference in how employees see their company.

Aged↗
PubMed1991

Uptake, metabolism, and cytotoxicity of isomeric cholesterol-5,6-epoxides in rabbit aortic endothelial cells.

The isomeric cholesterol-5,6-epoxides represent two common cholesterol autoxidation products and along with their principal metabolic product, 3 beta,5 alpha,6 beta-cholestane triol, are purportedly angiotoxic. The uptake and cytotoxic action of these compounds was examined in cultured rabbit aortic endothelial cells emphasizing mechanisms of uptake and metabolic fate. The isomeric cholesterol epoxides are incorporated with equal facility and in a dose-dependent manner. The pattern of uptake, which is markedly influenced by media serum concentration and by temperature, suggests that these compounds are partly incorporated through association with serum lipoproteins. After incorporation, both epoxide isomers are rapidly converted to cholestane triol which readily exits the cells. Cholestane triol is further metabolized to an ester-type product representing up to 10% of the added cholesterol epoxides by 24 h of incubation. The order of cytotoxic potency of these cholesterol oxides is: cholestane triol greater than cholesterol-beta-epoxide greater than cholesterol-alpha-epoxide, with LD50 concentrations ranging from 23 to greater than 150 microM in confluent cells. Cholestane triol and cholesterol-beta-epoxide are twice as cytotoxic to subconfluent cells as compared to confluent cells, whereas cholesterol-alpha-epoxide is essentially equitoxic to confluent and subconfluent cells. Cholesterol epoxide cytotoxicity is significantly reduced by treatments in the absence of serum in accord with substantial reduction in uptake when incubations are performed in serum-free media. Our findings show that these cytotoxic cholesterol oxides are incorporated by endothelial cells through a combination of receptor-mediated and nonspecific or passive mechanisms; however, the efficacy of uptake and resulting toxicity is substantially influenced by serum lipoproteins.

Animals↗
PubMed1990

Cutaneous vasculitis associated with pheochromocytoma.

We describe a patient who presented with constitutional symptoms, severe hypertension, and purpuric lesions over the knees, thighs, and penis. The patient was eventually diagnosed as having multiple endocrine neoplasia type II, with cutaneous leukocytoclastic vasculitis. The cutaneous vasculitis persisted despite treatment with high-dose systemic corticosteroids, but rapidly resolved after the removal of bilateral pheochromocytomas. This case demonstrates cutaneous leukocytoclastic vasculitis in association with pheochromocytoma.

Adrenal Cortex Hormones↗