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Biomedical subjects

T Rhodes

Publications and source records attributed to T Rhodes.

At least 73 records · Page 4Linked to original sources
PubMed1994

Natural history of prostatism: worry and embarrassment from urinary symptoms and health care-seeking behavior.

OBJECTIVE: To assess the interrelationships among psychosocial symptoms of worry and embarrassment about urinary function, prevalent urinary symptoms, psychological well-being, and health care-seeking behavior in a population-based cohort of men. METHODS: A cohort of 2,119 men aged forty to seventy-nine years, randomly selected from the Olmsted County, Minnesota population between December 1989 and March 1991, were administered a previously validated questionnaire that elicited information about the frequency of urinary symptoms, the degree to which they were perceived as a bother, and if the participant had seen a doctor in the previous twelve months for evaluation of any of these urinary symptoms. Psychological well-being was assessed by a subset of the Psychological General Well-Being Index, and sociodemographic information was also sought. RESULTS: Urinary symptom indices (measured by American Urological Association frequency and bother scores and psychological general well-being subscales) were significantly associated with worry and embarrassment about urinary symptoms in bivariate analyses. Multiple logistic regression analyses demonstrated that men with moderate or severe urinary symptoms or impaired psychological well-being were more likely to be worried or embarrassed about their urinary symptoms than men with mild symptoms. Furthermore, men who were worried about their urinary function were more likely to have sought medical care for their symptoms than men who were not worried. The association between health care-seeking behavior and embarrassment was especially strong among men with little bother associated with their urinary symptoms. CONCLUSIONS: Worry and embarrassment about urinary symptoms reflect quality-of-life issues that appear important in the health care-seeking behavior of men with prostatism. The results underscore findings that prevalent urinary symptoms alone do not determine a man's health care-seeking behavior, and treatment for psychosocial symptoms may be beneficial in some men with symptoms of prostatism.

Adult↗
PubMed1994

A comparison of rhodamine 123 accumulation and efflux in cells with P-glycoprotein-mediated and MRP-associated multidrug resistance phenotypes.

Rhodamine 123 (Rh123) is a fluorescent dye which locates in the mitochondria of cells. It is a substrate for P-glycoprotein (Pgp) and can, therefore, be used as a molecular probe in studies of the multidrug resistance (MDR) phenotype. However, not all MDR cells overexpress Pgp. In some, the MDR phenotype is associated with expression of an alternative transporter molecule, the multidrug resistance-associated protein (MRP). We have studied the accumulation and efflux of Rh123 in MDR cells having both Pgp-mediated and MRP-associated phenotypes. In the mouse tumour parental cell line, EMT6/P, Rh123 accumulates rapidly to reach plateau levels by 90 min. Confocal microscopy confirms a localisation to the mitochondria. In the MDR subline, EMT6/AR1.0, which overexpresses Pgp and which is 10-fold resistant to Rh123 cytotoxicity, accumulation is dramatically reduced. Efflux of Rh123 from both resistant and parental lines is rapid but can be inhibited by reduced temperature or by the presence of cyclosporin A (5 micrograms/ml). Efflux from the parental line is probably due to the presence of very low, but detectable, levels of Pgp but the existence of other mechanisms cannot be ruled out. In contrast, the human lung cancer parental cell line COR-L23/P, and its MRP-associated (but Pgp-negative) MDR subline, COR-L23/R (which is 23-fold resistant to Rh123 cytotoxicity), accumulate Rh123 at similar rates for the first 30 min. The curves then diverge so that, at 180 min, the resistant cells contain only 70% of the Rh123 of parental cells. Confocal microscopy demonstrates a similar distribution of fluorescence in resistant and parental cells. Essentially no efflux of Rh123 occurs from parental cells, whereas 70% of the content is lost from resistant cells over a period of 150 min. Such efflux may again be inhibited by reduced temperature but cyclosporin A (5 micrograms/ml) has little effect. These observations should be borne in mind when interpreting Rh123 efflux data in terms of MDR mechanisms.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Modification by brefeldin A, bafilomycin A1 and 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD) of cellular accumulation and intracellular distribution of anthracyclines in the non-P-glycoprotein-mediated multidrug-resistant cell line COR-L23/R.

We have investigated the effects of H(+)-ATPase inhibitors, bafilomycin A1 and 7-chloro-4-nitro-benz-2-oxa-1,3 diazole (NBD), and the Golgi inhibitor, brefeldin A, on daunorubicin accumulation and doxorubicin intracellular distribution in the non-P-glycoprotein-mediated multidrug-resistant cell line COR-L23/R. This cell line overexpress a 190 kDa protein which is probably the product of the MRP gene and shows an anthracycline accumulation defect and a drastically altered intracellular anthracycline distribution from the parental cell line COR-L23/P. We found that all three agents could selectively increase the cellular accumulation of daunorubicin in resistant cells. However, these effects were only seen at doses of the modifiers which were equal to or greater than the IC50 of the modifier alone. Effects of the modifiers on the intracellular distribution of doxorubicin fluorescence could, however, be seen at doses lower than those required to produce significant effects on daunorubicin accumulation. However, when used in a continuous MTT chemosensitivity assay none of the agents, used at maximum non-toxic doses, was able to sensitise COR-L23/R cells to doxorubicin or to colchicine. Although these lead compounds are unlikely to be useful as clinical modifiers, development of more selective analogues may prove useful in the modification of non-P-glycoprotein-mediated multidrug resistance.

4-Chloro-7-nitrobenzofurazan↗
PubMed1994

HIV prevalence no higher among female drug injectors also involved in prostitution.

To assess the prevalence of HIV infection among female drug injectors involved in prostitution and female drug injectors not involved in prostitution, survey-based interviews were undertaken with 308 female drug injectors in 1990 and 1991. Confirmed saliva test results show 12.9% HIV prevalence among female drug injectors involved in prostitution and 14.4% HIV prevalence among drug injectors not involved in prostitution. This gives an HIV prevalence rate of 14.2% among female drug injectors overall. Findings also show that women not involved in prostitution were less likely to be in contact with a drug treatment or helping agency and were less likely to report having had an HIV test. Respondents in contact with a treatment agency and respondents involved in prostitution were more likely to be aware of their HIV status, and 72% of non-prostitute women confirmed HIV positive were unaware of their positive status. These findings of no higher HIV prevalence among female drug injectors also involved in prostitution lend some support to emerging evidence which associates HIV transmission among women prostitutes with an involvement in injecting drug use rather than with an involvement in prostitution per se. Findings also strengthen the need for greater expansion and greater accessibility of HIV testing, counselling and prevention facilities in community locales where drug injection and prostitution is prevalent.

Adolescent↗
PubMed1994

Sexual behaviour of drug injectors in London: implications for HIV transmission and HIV prevention.

The importance of sharing injecting equipment in the transmission dynamics of HIV is well established. Comparatively less is known about the sexual behaviour of drug injectors and the risks posed to themselves and their sexual partners through the sexual transmission of HIV. Findings are reported from survey-based interviews undertaken in 1991 which investigated the sexual behaviour of 516 drug injectors, both in and out of treatment in London. The majority of respondents (80%) were sexually active in the 6 months preceding interview. During this time, respondents had a mean of 2.1 non-commercial opposite sex partners. Most (66%) had vaginal intercourse at least once a week, although 68% never used condoms with primary partners and 34% never used condoms with casual partners. Those having sexual intercourse most often were less likely to use condoms. Many had non-injecting sexual partners, and 62% of respondents' primary and casual partners did not inject drugs. Confirmed saliva HIV test results show 10% of respondents to be antibody positive, with a higher rate of prevalence (14% positive) among those with no experience of treatment. This group were also more likely to report casual sexual intercourse. The average rate of partner change, the high proportion of drug injectors with non-injecting partners and the infrequency of condom use within primary and causal relationships indicates the potential for HIV transmission between injectors and their non-injecting sexual partners. The paper concludes by emphasizing the importance of outreach and community-based intervention in safer sex health promotion.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Potential development of community oriented HIV outreach among drug injectors in the UK.

Given the current epidemiological and behavioural risk profile of HIV infection among injecting drug users in the UK, the main strategic task continues to be to develop interventions to prevent the spread of HIV infection. Outreach to drug injectors is an important part of the wider UK HIV prevention strategy. This paper reviews critically and reassesses practically the role of outreach interventions among drug injectors in the UK. It is argued that despite the development of innovative outreach activity, the full potential of outreach has not been realized due to its theoretical orientation and in-built structural limitations. Outreach has predominantly operated with an 'individual' orientation, aiming to work with individual clients to help them to change their behaviour, gain access to services, or to become better users of services. The main thesis of this paper is that current outreach provision needs to be complemented by 'community change' models which seek to engender changes in the social etiquette of drug use within communities of drug injectors. The paper argues that the social networks through which HIV may be transmitted are the same social networks that may be coopted for HIV prevention. Future outreach services must turn to these networks as a way of targeting and encouraging changes among broad populations of drug injectors. Such models might use indigenous advocates, working within social networks, supported by community outreach facilitators.

Community Health Services↗
PubMed1993

Chemosensitisation and drug accumulation effects of cyclosporin A, PSC-833 and verapamil in human MDR large cell lung cancer cells expressing a 190k membrane protein distinct from P-glycoprotein.

The doxorubicin-selected multidrug resistant (MDR) human large cell lung cancer line COR-L23/R, lacks P-glycoprotein but shows a drug accumulation deficit. It does however overexpress a 190k membrane protein which shares an epitope with, but is otherwise distinct from, P-glycoprotein. The resistant cells show only a small sensitisation to vincristine and daunorubicin on treatment with cyclosporin A and its more potent analogue, PSC-833 despite an increase in drug accumulation. Verapamil, another effective resistance modifier in P-glycoprotein MDR cells, is slightly more effective. Fluorescent daunorubicin distributes in the cytoplasm and nucleus of sensitive parent COR-L23 cells but is confined to cytoplasmic perinuclear vesicles in resistant cells. Addition of cyclosporin A or PSC-833 slightly increases cytoplasmic fluorescence whereas verapamil also increases nuclear fluorescence. Resistance in this non-P-glycoprotein MDR line, COR-L23/R where these resistance modifiers have little effect may be associated with expression of the 190k protein.

Carcinoma, Non-Small-Cell Lung↗
PubMed1993

Association among serum lipid and lipoprotein concentrations and physical activity, physical fitness, and body composition in young children.

OBJECTIVE: To examine the relationships among indicators of physical activity, physical fitness, and body composition with serum lipid and lipoprotein levels in young children. DESIGN: Cross-sectional and 1-year prospective cohort. SETTING: Studies of Child Activity and Nutrition (SCAN) program, Galveston, Tex. SUBJECTS: One hundred twenty-three 4- or 5-year-old black, Hispanic (of Mexican origin), and white children. MEASUREMENTS: Body composition, resting heart rate, and cardiovascular fitness variables and serum lipid and lipoprotein levels were measured at age 3 or 4 years (study year 1) and at age 4 or 5 years (study year 2), and day-long heart rate was measured and the Children's Activity Rating Scale was administered between study years 1 and 2. RESULTS: Year-1 waist/hip ratios were inversely correlated with total serum cholesterol (TSC) and low-density lipoprotein (LDL) levels. Mean activity level was inversely correlated with waist/hip ratios. On the basis of multiple regression analysis, the sum of seven skin-fold measurements, height, and gender explained 15.4% of the variation in triglyceride levels. The sum of seven skin-fold measurements was inversely correlated with the high-density lipoprotein (HDL) level. Resting heart rate, waist/hip ratio, and the slope of the exercise heart rate during fitness testing explained 19.5% of the variation in the concentration of an HDL subclass, HDL2. These children's levels of physical activity were associated with higher fitness levels. Year-1 waist/hip ratios and year-2 sum of seven skin-fold measurements were positively correlated with the LDL/HDL and TSC/HDL ratios. CONCLUSION: Higher levels of cardiovascular fitness and lower levels of fatness were associated with more favorable serum lipid and lipoprotein levels in these young children. Physical activity appeared to have an indirect association with serum lipid and lipoprotein values through its relationship with higher fitness levels and lower levels of fatness.

Activities of Daily Living↗
PubMed1993

Evaluation of the Children's Activity Rating Scale (CARS) in young children.

We describe the daily activity patterns and the between-day and -year reliabilities of the Children's Activity Rating Scale (CARS) measured in 180 Anglo-, African-, and Mexican-American children aged 3 or 4 yr. Reliabilities were assessed at up to 11 measurement periods over 3 yr. CARS scores were measured by two trained observers (alternating 2-h shifts) up to 12 working hours. There were no significant ethnic or day of week differences in the activity levels. Males had higher mean activity levels than females and higher activity was performed in the summer and fall than the spring or winter. The all-measurements reliability for a mean of 5.34 d of observation over the 3 yr of measurement was 0.57. The reliability across all days and years of measurement was 0.73. The highest level of reliability (0.75) was found for the percent of minutes spent at CARS levels 3, 4, or 5 followed by an intraclass correlation of 0.74 for percent of minutes spent at CARS levels 4 or 5. These data support the utility of using the CARS as a measure of physical activity in younger children from different ethnic groups.

Activities of Daily Living↗
PubMed1993

Reliability and variability of indicators of heart-rate monitoring in children.

We describe the daily heart-rate patterns and the between-day and within-day reliabilities of several heart rate indicators measured in 131 Anglo-, African-, and Mexican-American children aged 5-7 yr. Heart rates were measured over 12 waking hours with a Quantum XL Telemetry heart rate monitor. The percent of heart rates 25% above resting heart rate, an index of physical activity heart rate (PAHR-25 index), was found to have the highest within-day (0.92) and between-day (0.81) reliabilities. The Spearman-Brown prophecy formula indicated that only 9.3 h of observation would be needed to maintain a within-day reliability of 0.90. The percentage of heart rates 50% above resting heart rate (PAHR-50) was found to have slightly lower within-day (0.88) and between-day (0.56) reliability. Principal components analysis revealed that the PAHR-25 and PAHR-50 indicies only had one component throughout the day. The PAHR-25 and PAHR-50 indicies were weakly correlated with age, suggesting that they may be good indicators of relative PAHR. Male children had higher (P < or = 0.025) PAHR-25 index scores than females. There were no gender or ethnic differences in the PAHR-50 index.

Black or African American↗
PubMed1992

A study of ethacrynic acid as a potential modifier of melphalan and cisplatin sensitivity in human lung cancer parental and drug-resistant cell lines.

We have studied alterations in glutathione (GSH) levels and glutathione-S-transferase (GST) activity in a series of in vitro derived multidrug resistant and cisplatin resistant sublines of the human lung cancer lines NCI-H69 (small cell), COR-L23 (large cell) and MOR (adenocarcinoma). We have also investigated the effects of ethacrynic acid, a putative inhibitor of GSTs, on levels of GSH and GST activity and on cellular sensitivity to melphalan and to cisplatin. Neither GSH content nor GST activity were significantly greater in the resistant sublines compared with their respective parental lines. The only effects of treating with ethacrynic acid at doses of 1 microgram ml-1 and 3 micrograms ml-1 for 2 h were a reduction in GSH content in the cisplatin resistant subline H69/CPR at the 3 micrograms ml-1 dose, and an increase to over 140% of control at 1 microgram ml-1 and 3 micrograms ml-1 in the MOR parental line (MOR/P) and at 1 microgram ml-1 in the multidrug resistant subline MOR/R. Exposure of parental line COR-L23/P to 3 micrograms ml-1 and 6 micrograms ml-1 of ethacrynic acid for 24 h, however, increased the GSH content to over 300% and 500% of control respectively. Variable effects of ethacrynic acid on GST activity were seen in these cell lines. Doses of 1 microgram ml-1 and 3 micrograms ml-1 reduced activity to 59% and 48% of control respectively in multidrug resistant subline H69/LX4. On the other hand, activity was increased in the cisplatin resistant subline H69/CPR (to 146% and 218% of control) and in MOR/P (to 117% and 137% of control) by 1 microgram ml-1 and 3 micrograms ml-1 respectively of ethacrynic acid. Addition of ethacrynic acid (3 micrograms ml-1) to treatment of the cell lines with melphalan or with cisplatin did not alter the dose-response curves to these agents.

Adenocarcinoma↗
PubMed1992

Reliability and variability of heart rate monitoring in 3-, 4-, or 5-yr-old children.

We describe the daily heart rate patterns and the between day and within day reliabilities of several heart rate variables measured in 159 Anglo-, African-, and Mexican-American children aged 3-5 yr. Heart rates were measured over 12 waking hours with a Quantum XL Telemetry heart rate monitor. There were no significant ethnic, gender, day of week, or season of the year differences in either mean resting heart rate, mean daily heart rate, mean longest duration of the heart rate sustained above 120 bpm for the day, nor percent of minutes of daily heart rate above 120 bpm. The reliabilities for these variables for 2 d of observation separated by 3-6 months ranged from 0.65 to 0.66. At this level of reliability, just over 4 d of recording are necessary to achieve a reliability of 0.80. All within-day across-hour reliabilities were greater than 0.80. However, for mean hourly heart rate and the longest duration of heart rate sustained above 120 bpm each hour, a principal components analysis revealed three distinct time components during the day. This suggests that monitoring heart rate during limited portions of the day will provide a biased estimate of overall heart rate. For the morning component, there were significant ethnic and gender differences in the children's heart rates and younger children had longer durations of heart rate sustained above 120 bpm than older children. Although daily heart rate monitoring is not a perfect indicator of children's physical activity, these data suggest that it may be a reliable measure among younger children from different ethnic and gender groups.

Black People↗
PubMed1991

Radiation response of human lung cancer cells with inherent and acquired resistance to cisplatin.

We have derived sublines of three human lung cancer cell lines with acquired resistance to cisplatin. The cisplatin resistant sublines of NCI-H69 (small cell), COR-L23 (large cell), and MOR (adenocarcinoma) show 5.3 fold, 3.1 fold, and 3.8 fold resistance, respectively, determined in a 6-day MTT assay. Although the parent lines show a wide range of glutathione content per cell, the sublines each show similar values to their corresponding parent line. Radiation response curves have been obtained using a soft agar clonogenic assay. Values obtained for the parent lines (95% CL in parentheses) were: NCI-H69: Do = 0.99 Gy (0.87-1.16), n = 2.9 (1.6-5.2), GSH = 14 ng/10(4) cells; COR-L23: Do = 1.23 Gy (1.05-1.49), n = 1.3 (0.7-2.2), GSH = 47 ng/10(4) cells; MOR: Do = 1.66 Gy (1.48-1.88), n = 3.0 (1.9-4.8), GSH = 86 ng/10(4) cells. The cisplatin resistant variants of NCI-H69 and COR-L23 showed 31% and 63% increases, respectively, in Do compared to their parent lines, whereas no change in radiation response was seen in MOR. In this panel of lines, therefore, although there is a correlation between glutathione content and radiosensitivity of the parent cell lines, acquired resistance to cisplatin is not accompanied by increased glutathione content. However, two of the three cisplatin resistant lines do show a significantly reduced radiosensitivity.

Adenocarcinoma↗
PubMed1991

Immunoglobulin heavy chain patterns in reactive lymphadenopathy.

Thirty one lymph nodes taken from 24 benign reactive cases, three cases of angiolymphoid hyperplasia with eosinophilia, one case of Kimura's disease and three cases of Hodgkin's disease, were stained for immunoglobulin heavy chains IgG, IgM, IgA and IgE using the peroxidase-antiperoxidase method. Reticular staining of germinal centres and cells containing immunoglobulin in germinal centres and extrafollicular regions were features of all groups. No staining pattern was diagnostic for any of these conditions and in particular, the reticular staining pattern of IgE in the germinal centres that is frequently reported in Kimura's disease and in angiolymphoid hyperplasia with eosinophilia was non-specific.

Angiolymphoid Hyperplasia with Eosinophilia↗
PubMed1990

HIV and measures to control infection in general practice.

OBJECTIVE: To assess the impact of HIV on procedures to control infection in general practices. DESIGN: A postal questionnaire survey. SETTING: General practices throughout Britain. SUBJECTS: 5359 General practitioners, 3429 (63.9%) of whom returned the questionnaire. MAIN OUTCOME MEASURE: Response to questionnaire on knowledge about HIV and policies for controlling infection. RESULTS: Most doctors (2018) had started to wear gloves when taking blood. Almost half (1510) had not resheathed needles previously but a further 776 had adopted this policy because of HIV. Over half of the doctors did not know or were unsure about the risk of infection from needlestick injuries, and 1759 had no practice policy for controlling infection. CONCLUSIONS: Many doctors are uncertain about measures to control infection in general practice. More information and advice are needed to help doctors develop policies to protect patients and staff.

Acquired Immunodeficiency Syndrome↗