Biomedical subjects

P S Wang

Publications and source records attributed to P S Wang.

At least 19 recordsLinked to original sources

PubMed2003

An immune signalling kinase AaMEK3 from mosquitoes: cDNA cloning and characterization.

In mammals, the mitogen-activated protein (MAP) kinase pathway is one of the four major signalling systems that respond to stress and inflammatory stimuli. A full-length cDNA corresponding to Aedes aegypti MAP kinase kinase 3 (AaMEK3) was cloned and sequenced. It is 1.7 kb and contains an open reading frame of 334 amino acids and eleven conserved kinase domains, including signatures of a putative serine/threonine kinase active site and an ATP binding site. The messenger (mRNA) and protein expression levels of AaMEK3 are enhanced post bacterial inoculation. The in vitro kinase activity assay reveals that (1) AaMEK3 is not autophosphorylated but can phosphorylate myelin basic protein successfully, and (2) it is slightly enhanced by lipopolysaccharide stimulation. This suggests that AaMEK3 may be involved in mosquito immune signalling.

Aedes↗

PubMed2002

Pleural effusion and serum soluble fas-ligand levels are elevated in different clinical conditions.

Fas ligand (FasL) plays an important role in the regulation of apoptosis. Soluble FasL (sFasL) is produced by a cleavage of FasL from the cell surface by metalloproteinase. Whether or not sFasL exists or is elevated in the pleural effusion of different etiologies is unknown. The present study is designed to determine pleural effusion and serum sFasL levels under different clinical conditions, and ascertain if there exists a significant difference in the levels found in different clinical conditions, and whether this difference can be used as a tool for differential diagnosis. Soluble FasL levels in the pleural effusion and serum of 103 patients, including 37 with malignant pleural effusion, 24 with uncomplicated parapneumonic effusion, 8 with bacterial empyema, 16 with tuberculous pleurisy, and 18 with transudate effusion (8 with congestive heart failure and 10 with viral liver cirrhosis), were analyzed with ELISA assays. Pleural effusion from patients with bacterial empyema (median 79.4 pg/ml) and TB pleurisy (median 31.9 pg/ml) contained significantly higher amounts of sFasL than the pleural effusion from all other conditions studied (p <0.001). Viral liver cirrhosis had a significantly higher serum sFasL level (median 53.6 pg/ml, p = 0.025, when compared with other patients). Patients with congestive heart failure had the lowest serum sFasL levels when compared with other patients (p = 0.014). There was no significant correlation between pleural effusion sFasL levels and other parameters, such as effusion LDH, cell count, neutrophil, and lymphocyte percentage. In conclusion, soluble FasL is a useful marker for the differentiation of bacterial empyema and TB pleurisy from other disease entities. In addition, the elevation of serum sFasL levels in viral liver cirrhosis can also be used to differentiate cirrhosis from congestive heart failure, in which both effusions are transudate.

Aged↗

PubMed2002

Involvement of cholecystokinin receptor in the inhibition of gastrointestinal motility by estradiol in ovariectomized rats.

BACKGROUND: The effects of estradiol benzoate (EB) on gastric emptying, gastrointestinal transit and plasma levels of cholecystokinin (CCK) were studied in ovariectomized rats. METHODS: Gastrointestinal motility was assessed in rats 15 min after intragastric instillation of a test meal containing charcoal and Na2 51CrO4. Gastric emptying was determined by measuring the amount of radiolabeled chromium contained in the small intestine as a percentage of the initial amount received. Gastrointestinal transit was evaluated by calculating the geometric center of distribution of the radiolabeled marker. Blood samples were collected for E2 and CCK radioimmunoassay. RESULTS: After treatment of EB (4-25 microg/kg), gastric emptying and gastrointestinal transit were inhibited, whereas plasma concentrations of E2 and CCK were increased in a dose-dependent manner. The selective CCK(A) receptor antagonists, devazepide and lorglumide, effectively attenuated the EB-induced inhibition of gastric emptying and gastrointestinal transit. L-365,260, a selective CCK(B) receptor antagonist, did not alter the EB-induced inhibition of gastric emptying and gastrointestinal transit. CONCLUSIONS: The results suggest that EB inhibits gastric emptying and gastrointestinal transit in ovariectomized rats via a mechanism involving CCK stimulation and CCK(A) receptor activation.

Animals↗

PubMed2001

Performance of comorbidity scores to control for confounding in epidemiologic studies using claims data.

Comorbidity is an important confounder in epidemiologic studies. The authors compared the predictive performance of comorbidity scores for use in epidemiologic research with administrative databases. Study participants were British Columbia, Canada, residents aged >or=65 years who received angiotensin-converting enzyme inhibitors or calcium channel blockers at least once during the observation period. Six scores were computed for all 141,161 participants during the baseline year (1995-1996). Endpoints were death and health care utilization during a 12-month follow-up (1996-1997). Performance was measured by using the c statistic ranging from 0.5 for chance prediction of outcome to 1.0 for perfect prediction. In logistic regression models controlling for age and gender, four scores based on the International Classification of Diseases, Ninth Revision (ICD-9) generally performed better at predicting 1-year mortality (c = 0.771, c = 0.768, c = 0.745, c = 0.745) than medication-based Chronic Disease Score (CDS)-1 and CDS-2 (c = 0.738, c = 0.718). Number of distinct medications used was the best predictor of future physician visits (R(2) = 0.121) and expenditures (R(2) = 0.128) and a good predictor of mortality (c = 0.745). Combining ICD-9 and medication-based scores improved the c statistics (1.7% and 6.2%, respectively) for predicting mortality. Generalizability of results may be limited to an elderly, predominantly White population with equal access to state-funded health care.

Aged↗

PubMed2001

Inhibitory effect of evodiamine on aldosterone release by Zona glomerulosa cells in male rats.

Evodiamine is a bioactive alkaloid extracted from a Chinese herb named Wu-Chu-Yu, which possesses thermoregulatory, analgesic, and cardiovascular effects. Some studies have demonstrated that evodiamine reduces blood pressure through acting on endothelium and smooth muscle cells to produce a vasodilatory effect, but whether it affects aldosterone secretion is unclear. The purpose of this study was to examine the effect of evodiamine on aldosterone release in adrenal zona glomerulosa (ZG) cells. ZG cells were isolated from the adrenal glands of adult male rats and incubated with angiotensin II (Ang II, 1x10(-7) M) and 3H-pregnenolone in the presence or absence of evodiamine (1x10(-6)-1x10(-3) M) at 37 degrees C for one hour. The concentration of aldosterone in the media was measured by a radioimmunoassay. The level of radioactivity incorporated into aldosterone and its precursors after incubation of ZG cells with 3H-pregnenolone was analyzed by thin-layer chromatography. The results demonstrated that evodiamine decreased the basal level of and Ang II-induced release level of aldosterone in rat ZG cells. Administration of evodiamine also decreased the level of radioactivity incorporated into 3H-corticosterone and 3H-aldosterone following incubation of ZG cells with 3H-pregnenolone. This suggest that evodiamine affects aldosterone release in rat adrenal glomerulosa cells by acting on Ang II-associated pathway and reducing the activity of 11 beta-hydroxylase (an enzyme which coverts deoxycorticosterone to corticosterone) during the steroidogenesis of aldosterone.

Aldosterone↗

PubMed2001

The simulation effects of mountain climbing training on selected endocrine responses.

The simulation effects of mountain climbing exercise training on plasma testosterone, cortisol and luteinizing hormone (LH) levels were examined in ten recreational mountain male climbers. Subjects underwent a simulating mountain climbing exercise training 3 times a week for a total of eight weeks before an expedition to Mount Muztag Ata (7546 m, Xingian, China). During training, each subject carried a 40 kg back pack while walking on a treadmill at a speed of 1.9 mph for 60 min at sea level. Subjects completed an incremental treadmill test to exhaustion prior to training, after training, and one week after returning from Mount Muztag Ata. Blood samples were collected from antecubital vein at rest and at 5, 60, and 120 min post testing to determine the plasma testosterone, cortisol and LH levels. The basal plasma testosterone and cortisol concentrations were lower in both post-training and after-climbing conditions compared with that in the pre-training condition (p<0.01). The basal plasma LH concentration was remained unchanged after training and after the mountain climbing compared with levels measured in the pre-training phase. No correlation could be established between plasma LH and testosterone level. These results suggest that an eight-week period of mountain climbing training protocol may be beneficial in maintaining normal endocrine function during and after high altitude mountain expedition. Our results also indicate the decrease of plasma testosterone was LH independent.

Adult↗

PubMed2001

Effects of hyperprolactinemia on testosterone production in rat Leydig cells.

The pathogenesis of hyperprolactinemia (hyperPRL) induced hypogonadism has been suggested to be related with a dysfunction of hypothalamus-pituitary-testis axis. While the direct inhibitory effects of prolactin (PRL) on testosterone (T) release have been demonstrated, the mechanism is still unclear. Our previous study demonstrated a diminished T release in the testicular interstitial cells (TICs) from the anterior pituitary (AP)-grafted rats as compared with the control, and the pattern was in agreement with the in vivo model. However, TICs incubation cannot totally represent the response of the Leydig cells. Therefore, a Percoll gradient purified Leydig cell model was adopted to explore the response of T release under similar challenges in this study to investigate the effects of hyperPRL on the Leydig cells per se. HyperPRL in male rats was induced by grafting rat AP under the renal capsule. The control animals were grafted with rat brain cortex tissue (CX). Six weeks after grafting, the rats were sacrificed. Either TICs or Leydig cells were isolated, respectively, for in vitro incubation and challenge. Challenge drugs included human chorionic gonadotropin (hCG, 0.05 IU/ml), steroidogenic precursors (25-OH-cholesterol, 10(-6) M; pregnenolone, 10(-6) M), forskolin (an anenylyl cyclase activator, 10(-4) M) and 8-bromo-3':5' cyclic adenosine monophosphate (cAMP) (8-Br-cAMP 10(-4) M). T released by TICs or Leydig cells was determined by radioimmunoassay. The TICs from the AP-grafted rats showed lower levels of T release than the control group while the purified Leydig cells demonstrated a reverse pattern in response to challenges of hCG, steroidogenic precursors, forskolin and 8-Br-cAMP. In hyperPRL rats, a paradoxical pattern of T release between TICs and purified Leydig cells is observed. The purified Leydig cells from AP-grafted rats demonstrated a higher level amount of T release than the control after stimulation. The phenomenon can be attributed to the change of Leydig cell sensitivity to the stimulation after the effects of chronic hyperPRL. Moreover, another possibility is the role played by other interstitial cells to modulate steroidogenesis in Leydig cells.

Animals↗

PubMed2001

Antidepressant use and the risk of breast cancer: a non-association.

OBJECTIVE: Animal studies have suggested that some antidepressant medications may act as breast tumor promoters and recent epidemiologic studies of antidepressant use and breast cancer outcomes in humans have also reported such associations. DESIGN: Retrospective cohort study. STUDY POPULATION: 38,273 women who filled a prescription for any of a number of antidepressants and 32,949 who filled a prescription for any other medication during 1989-1991; all were > or =20, enrolled in Medicare, Medicaid or the Pharmaceutical Assistance to the Aged and Disabled (PAAD) programs of New Jersey, and free of evidence of breast cancer. DATA COLLECTION: Antidepressant use was assessed over a period lasting up to 24 months. Subjects were followed for a maximum of 7.5 years; those who had a first diagnosis of breast cancer in the New Jersey Cancer Registry at least 3 months after their index date were considered incident breast cancer cases. Other covariates, including demographic, clinical, and health care utilization variables were also assessed. MAIN OUTCOME OF INTEREST: Adjusted hazard ratio (HR) of developing breast cancer, based on multivariable proportional hazards models. RESULTS: Use of antidepressants was unrelated to the development of breast cancer (adjusted HR = 1.04; 95% CI 0.87-1.25). No elevated risks were found for specific antidepressants, including agents found to be breast tumor promoters in animal studies, as well as drugs thought to be associated with breast cancer in prior epidemiologic studies. There was no suggestion that breast cancer risks were increased with more intensive use of antidepressants or that antidepressant use is associated with a more severe stage of cancer at diagnosis. CONCLUSIONS: Despite recent reports from much smaller epidemiologic studies or laboratory animals, these results provide reassurance that antidepressant use is not associated with the development of breast cancer.

Adult↗

PubMed2001

Finding incident breast cancer cases through US claims data and a state cancer registry.

OBJECTIVE: With the increasing availability of automated health-care data, new methods are available to screen large populations for the presence of cancer diagnoses. However, it is crucial to evaluate how completely incident cancer cases can be ascertained using these data sources. METHODS: We used capture-recapture techniques to estimate the total number of incident breast cancer cases occurring within one state during a 3-year period. We then compared the ascertainment of these cases by the following two data sources: claims for breast cancer surgery recorded in Medicaid and Medicare data vs a cancer registry in the same state. RESULTS: Medicaid-Medicare breast cancer surgery claims identified 68% of the total estimated number of incident breast cancer cases while cancer registry data identified 78%. Case ascertainment improved markedly to 91% when both registry and Medicare-Medicaid data sources were used together. The sensitivity of ascertainment was lower for Medicaid-Medicare data among those aged under 65 and non-white; ascertainment was lower for the registry among women who were aged under 65, poor, and non-white. CONCLUSIONS: Combining health insurance claims data with a population-based cancer registry improved the identification of incident cases of breast cancer, and may be particularly useful among demographic groups found to be at highest risk of under-ascertainment such as younger women, the poor, and racial minorities.

Adult↗

PubMed2001

Direct inhibitory effect of digitalis on progesterone release from rat granulosa cells.

Digoxin (10(-7) - 10(-5) M) or digitoxin (10(-7) - 10(-5) M) decreased the basal and human chorionic gonadotropin (hCG)-stimulated release of progesterone from rat granulosa cells. Digoxin (10(-5) M) or digitoxin (10(-5) M) attenuated the stimulatory effects of forskolin and 8-bromo-cyclic 3' : 5'-adenosine monophosphate (8-Br-cAMP) on progesterone release from rat granulosa cells. Digoxin (10(-5) M) or digitoxin (10(-5) M) inhibited cytochrome P450 side chain cleavage enzyme (cytochrome P450(scc)) activity (conversion of 25-hydroxyl cholesterol to pregnenolone) in rat granulosa cells but did not influence the activity of 3beta-hydroxysteroid dehydrogenase (3beta-HSD). Neither progesterone production nor P450scc activity in rat granulosa cells was altered by the administration of ouabain. Digoxin (10(-5) M) or digitoxin (10(-5) M), but not ouabain, decreased the expression of P450scc and steroidogenic acute regulatory (StAR) protein in rat granulosa cells. The present results suggest that digoxin and digitoxin decrease the progesterone release by granulosa cells via a Na(+),K(+)-ATPase-independent mechanism involving the inhibition of post-cyclic AMP pathway, cytochrome P450scc and StAR protein functions.

Adenylyl Cyclases↗

PubMed2001

Depression and work productivity: the comparative costs of treatment versus nontreatment.

This article discusses the impact of depression on work productivity and the potential for improved work performance associated with effective treatment. We undertook a review of the literature by means of a computer search using the following key terms: cost of illness, work loss, sickness absence, productivity, performance, and disability. Published works were considered in four categories: (1) naturalistic cross-sectional studies that found greater self-reported work impairment among depressed workers; (2) naturalistic longitudinal studies that found a synchrony of change between depression and work impairment; (3) uncontrolled treatment studies that found reduced work impairment with successful treatment; and (4) controlled trials that usually, but not always, found greater reduction in work impairment among treated patients. Observational data suggest that productivity gains following effective depression treatment could far exceed direct treatment costs. Randomized effectiveness trials are needed before we can conclude definitively that depression treatment results in productivity improvements sufficient to offset direct treatment costs.

Absenteeism↗

PubMed2001

The effects of chronic medical conditions on work loss and work cutback.

Although work performance has become an important outcome in cost-of-illness studies, little is known about the comparative effects of different commonly occurring chronic conditions on work impairment in general population samples. Such data are presented here from a large-scale nationally representative general population survey. The data are from the MacArthur Foundation Midlife Development in the United States (MIDUS) survey, a nationally representative telephone-mail survey of 3032 respondents in the age range of 25 to 74 years. The 2074 survey respondents in the age range of 25 to 54 years are the focus of the current report. The data collection included a chronic-conditions checklist and questions about how many days out of the past 30 each respondent was either totally unable to work or perform normal activities because of health problems (work-loss days) or had to cut back on these activities because of health problems (work-cutback days). Regression analysis was used to estimate the effects of conditions on work impairments, controlling for sociodemographics. At least one illness-related work-loss or work-cutback day in the past 30 days was reported by 22.4% of respondents, with a monthly average of 6.7 such days among those with any work impairment. This is equivalent to an annualized national estimate of over 2.5 billion work-impairment days in the age range of the sample. Cancer is associated with by far the highest reported prevalence of any impairment (66.2%) and the highest conditional number of impairment days in the past 30 (16.4 days). Other conditions associated with high odds of any impairment include ulcers, major depression, and panic disorder, whereas other conditions associated with a large conditional number of impairment days include heart disease and high blood pressure. Comorbidities involving combinations of arthritis, ulcers, mental disorders, and substance dependence are associated with higher impairments than expected on the basis of an additive model. The effects of conditions do not differ systematically across subsamples defined on the basis of age, sex, education, or employment status. The enormous magnitude of the work impairment associated with chronic conditions and the economic advantages of interventions for ill workers that reduce work impairments should be factored into employer cost-benefit calculations of expanding health insurance coverage. Given the enormous work impairment associated with cancer and the fact that the vast majority of employed people who are diagnosed with cancer stay in the workforce through at least part of their course of treatment, interventions aimed at reducing the workplace costs of this illness should be a priority.

Absenteeism↗

PubMed2001

Zolpidem use and hip fractures in older people.

OBJECTIVES: The widespread use of sedative-hypnotics in older populations makes it imperative to identify hazardous regimens that should be avoided and safer regimens that may be used preferentially by older people. Although benzodiazepines have been shown to increase fall and fracture risk, zolpidem, a nonbenzodiazepine hypnotic, has been advocated as a safer alternative. DESIGN: Case-control study of hip fracture cases and controls in 1994. SETTING: All subjects were age 65 and older and enrolled in Medicare, and in Medicaid or the Pharmaceutical Assistance to the Aged and Disabled program of New Jersey. PARTICIPANTS: Cases (n=1,222) were patients who underwent surgical repair of a hip fracture. They were frequency-matched to four controls (n=4,888) based on age and gender. MEASUREMENTS: Use of sedative-hypnotics and other medications was assessed in the 180 days before the index event. We assessed other covariates, including demographic, clinical, and healthcare utilization variables in the prior 180 days. RESULTS: Zolpidem use was associated with a significant increased risk of hip fracture (adjusted odds ratio (AOR) 1.95; 95% confidence interval (CI)=1.09-3.51). Other psychotropic medication classes with significantly increased risks included benzodiazepines (AOR 1.46; 95% CI=1.21-1.76), antipsychotic medications (AOR 1.61; 95% CI=1.29-2.01), and antidepressants (AOR 1.46; 95% CI=1.22-1.75). In subanalyses, preferential use of zolpidem by subjects at greater risk of hip fracture did not appear to explain the apparent risk of hip fracture with zolpidem use. CONCLUSION: Use of zolpidem by older people was associated with nearly twice the risk of hip fracture, even after controlling for possible demographic and clinical confounders. Rather than being a safer alternative, zolpidem may be associated with risks that are as great as those seen with conventional benzodiazepines in older patients.

Aged↗

PubMed2001

Predictors of uncontrolled hypertension in ambulatory patients.

Hypertension remains poorly controlled in the United States. Improvement of its management will require an understanding of the patient characteristics and treatment factors associated with uncontrolled hypertension. We studied antihypertensive medication use, comorbidity, and blood pressure measurements for 525 hypertensive patients in 3 different healthcare systems over a 1-year period. We concomitantly conducted comprehensive patient interviews covering demographic factors, knowledge of hypertension and its treatment, and medication side effects. Ordinal logistic regression was used to identify factors associated with poor blood pressure control. Mean age of the patients was 65+/-11 years. Mean systolic blood pressure (SBP) was 143+/-15 mm Hg; and mean diastolic blood pressure (DBP), 80+/-9 mm Hg. Only 39% (203/525) of patients had mean blood pressure <140/90 mm Hg during the study period; about half (257/525) had stage 1 hypertension (mean SBP 140 to 159 mm Hg and/or mean DBP 90 to 99 mm Hg), and 12% (65/525) had stage 2 or greater hypertension (SBP >160 mm Hgand/or DBP >100 mm Hg). Multivariate analysis revealed several independent predictors of poor control: older age, multi-drug regimens, lack of knowledge by the patient of their target SBP, and a report of antihypertensive drug side effects. Patients with angina had a higher likelihood of adequate blood pressure control. Fewer than 40% of the treated patients studied had a mean blood pressure </=140/90 mm Hg, and specific patient-related factors appear to predict poor control. Some of these may be amenable to modification. Further identification of patients at risk of poor control can lead to targeted interventions to improve management.

Aged↗

PubMed2001

Hazardous benzodiazepine regimens in the elderly: effects of half-life, dosage, and duration on risk of hip fracture.

OBJECTIVE: While benzodiazepine treatment is known to increase the risk of hip fracture in older populations, controversy persists over which characteristics of benzodiazepine use (e.g., elimination half-life, dosage, duration of use) are most associated with such risks. METHOD: The authors reviewed the health care utilization data of 1,222 hip fracture patients and 4,888 comparison patients frequency matched on the basis of age and gender (all were at least 65 years old). Patients were enrolled in Medicare as well as in the New Jersey Medicaid or Pharmaceutical Assistance to the Aged and Disabled programs. Benzodiazepine use, as well as other covariates, were assessed before the index date (which was either the date of hospital admission for hip fracture surgical repair or, for the comparison subjects, a randomly assigned, frequency-matched date). RESULTS: All benzodiazepine doses > or =3 mg/day in diazepam equivalents significantly increased the adjusted risk of hip fracture by 50%. Significantly increased adjusted risks of hip fracture were seen during the initial 2 weeks of use (60% increase) and after more than 1 month of continuous use (80% increase) but not for 2-4 weeks of continuous use. Use of benzodiazepines other than long-acting agents significantly increased the risk of hip fracture by 50%. CONCLUSIONS: Even at modest doses, including some low doses currently advocated in prescribing guidelines for older patients, treatment with benzodiazepines appears to increase the risk of hip fracture. Patients appear to be particularly vulnerable immediately after initiating therapy and after more than 1 month of continuous use. Benzodiazepines with shorter half-lives appear to be no safer than longer half-life agents. Clinicians should be aware of these risks and weigh them against potential benefits when prescribing for elderly patients.

Aged↗

PubMed2001

Detecting suicide risk in a pediatric emergency department: development of a brief screening tool.

OBJECTIVE: To develop a brief screening tool that will allow emergency department (ED) staff to rapidly and accurately detect suicide risk in child and adolescent patients. DESIGN: Cross-sectional survey. Participants. One hundred forty-four children and adolescents, mean age of 13.6 years, presenting to an urban university teaching hospital pediatric ED for primarily psychiatric reasons. Data Collection. As part of a quality improvement initiative, we developed a 14-item screening survey (the Risk of Suicide Questionnaire [RSQ]) that was administered by a triage nurse to all pediatric mental health patients on admission to the ED. All patients were subsequently administered the 30-item Suicide Ideation Questionnaire (SIQ) by a mental health clinician, which served as the criterion standard assessment of suicidality. Other information collected included demographic and clinical characteristics. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value, negative predictive value (NPV), and area under the receiver operating characteristic curve for responses to individual and combinations of RSQ items, relative to determinations of suicidality by the criterion standard SIQ. RESULTS: Four of the items from the RSQ had a predictive c statistic of 0.87, a sensitivity of 0.98, and a NPV of 0.97. Little improvement in predictive ability was obtained by including other RSQ items (c statistic for the most predictive 4-item model = 0.87; c statistic for the model containing all 14 items = 0.90). Among all possible combinations of 4 RSQ items, the combination of items inquiring about current suicidal behavior, past suicidal ideation, past self-destructive behavior, and current stressors yielded the highest sensitivity (0.98), NPV (0.97), and c statistic (0.87), as assessed by the criterion standard SIQ. CONCLUSIONS: A brief 4-item screening tool can be used by nonmental health clinicians to accurately detect suicidality in children and adolescents who visit an ED. Early and accurate identification of suicidality is a critical first step that could lead to better treatment and improved health outcomes for children and adolescents with mental health concerns.

Adolescent↗

PubMed2001

Inhibitory effects of digitalis on the proliferation of androgen dependent and independent prostate cancer cells.

PURPOSE: Digitalis or cardiac glycosides have been noted to induce tumor static or oncolytic effects in various types of cancer. We evaluated the effects and underlying mechanisms of cardiac glycosides, including digoxin, digitoxin and ouabain, on the proliferation of hormone dependent and independent prostate cancer cell lines. MATERIALS AND METHODS: Cell proliferation of the 3 human prostate cancer cell lines LNCaP, DU145 and PC3 was measured by 3-(4,5-dimethylthiazol-2-yle)2,5-diphenyltetralozium bromide (Sigma Chemical Co., St. Louis, Missouri) colorimetric assay. The cytotoxic effects of digitalis on prostate cancer cells were determined by lactate dehydrogenase measurements of the culture medium. Intracellular Ca2+ was measured by a dual wavelength spectrometer system. The percent of apoptotic cells after digitalis treatment was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling and flow cytometry. RESULTS: Digoxin, digitoxin and ouabain significantly inhibited the proliferation of LNCaP, DU145 and PC3 cells at a dose of 1 or 10 microM. after 1 to 4 days of culture. Cytotoxicity of digitalis on the DU145 and LNCaP cells was dose dependent but cytotoxicity was not obvious in PC3. Digitalis (1 microM.) significantly increased intracellular Ca2+ in LNCaP and DU145 after 12 hours of culture but PC3 cells needed a 24-hour treatment to show any effect. In the apoptosis measurement digitalis at a dose of 1 and 10 microM. also significantly increased the percent of apoptotic cells in the LNCaP, DU145 and PC3 cell lines. Normal control human glomerular epithelial cells showed no response to digitalis treatment at all tested doses. CONCLUSIONS: Digitalis may inhibit the proliferation of prostate cancer cell lines, although the 3 cell lines showed varied sensitivity to digitalis. These effects are possibly the result of a mechanism involving sustained elevation of the concentration of intracellular Ca2+ and of apoptosis.

Apoptosis↗

PubMed2001

The prevalence and correlates of untreated serious mental illness.

OBJECTIVE: To identify the number of people in the United States with untreated serious mental illness (SMI) and the reasons for their lack of treatment. DATA SOURCE/STUDY DESIGN: The National Comorbidity Survey; cross-sectional, nationally representative household survey. DATA COLLECTION: An operationalization of the SMI definition set forth in the Alcohol, Drug Abuse, and Mental Health Administration Reorganization Act identified individuals with SMI in the 12 months prior to the interview. The presence of SMI then was related to the use of mental health services in the past 12 months. PRINCIPAL FINDINGS: Of the 6.2 percent of respondents who had SMI in the year prior to interview, fewer than 40 percent received stable treatment. Young adults and those living in nonrural areas were more likely to have unmet needs for treatment. The majority of those who received no treatment felt that they did not have an emotional problem requiring treatment. Among those who did recognize this need, 52 percent reported situational barriers, 46 percent reported financial barriers, and 45 percent reported perceived lack of effectiveness as reasons for not seeking treatment. The most commonly reported reason both for failing to seek treatment (72 percent) and for treatment dropout (58 percent) was wanting to solve the problem on their own. CONCLUSIONS: Although changes in the financing of services are important, they are unlikely by themselves to eradicate unmet need for treatment of SMI. Efforts to increase both self-recognition of need for treatment and the patient centeredness of care also are needed.

Adolescent↗