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Biomedical subjects

D Street

Publications and source records attributed to D Street.

At least 19 recordsLinked to original sources
PubMed2001

Interstitial pH in human skeletal muscle during and after dynamic graded exercise.

1. In this study a new method has been used to measure interstitial pH continuously in human muscle during graded exercise. Human subjects performed 5 min of one-legged knee-extensor exercise at power outputs of 30, 50 and 70 W. Muscle interstitial pH was measured continuously in microdialysis dialysate using the pH-sensitive fluorescent dye 2',7'-bis-(2-carboxyethyl)-5-(and -6)-carboxyfluorescein (BCECF). 2. The mean interstitial pH at rest was 7.38 +/- 0.02. Interstitial pH gradually reduced during exercise in a nearly linear manner. The mean value (range) of the lowest interstitial pH at 30, 50 and 70 W exercise was 7.27 (7.18-7.34), 7.16 (7.05-7.24) and 7.04 (6.93-7.12), respectively. 3. The lowest pH was obtained 1 min after exercise, irrespectively of the workload, after which interstitial pH recovered in a nearly exponential manner. The mean half-time for recovery was 5.2 min (range 4.1-6.1 min). The changes in interstitial pH exceeded the changes in venous blood pH. 4. The present study showed that interstitial pH decreased during exercise in relation to intensity. These pH changes could have implications for blood flow regulation as well as for modulations of membrane transport systems.

Acids↗
PubMed2000

Recalls of foods and cosmetics due to microbial contamination reported to the U.S. Food and Drug Administration.

In the U.S., food product recalls serve as an important intervention in stemming the consumption of food products contaminated with infectious disease agents. We summarize the number and nature of foods and cosmetics recalled as a result of microbial contamination reported to the U.S. Food and Drug Administration (FDA) for the period 1 October 1993 through 30 September 1998. During this period, microbial contamination of food and cosmetic products was the leading cause for recalls, accounting for a total of 1,370 recalls (36% of all products recalled). Listeria monocytogenes accounted for the greatest number of food products recalled because of microbial contamination, whereas Pseudomonas aeruginosa was the most common microbe associated with recalls of cosmetic products. Dairy products, followed by seafood and pastry items, were the types of products most often associated with recalls due to microbial contamination. The FDA was the entity most often responsible for detecting microbial contamination of foods and cosmetics (33% of all such recalls), followed by state regulatory agencies (24%), and manufacturers/retailers (21%). Nineteen percent of recalls were associated with at least one reported case of illness. Salmonella was the pathogen most often implicated in reports of illness associated with these recalled products.

Animals↗
PubMed1999

Endometrial lysosomal enzyme activity in normal cycling endometrium.

The objective of this study was to evaluate the possible role of four lysosomal enzymes in endometrial function and remodelling during the normal menstrual cycle by fluorimetric measurement (acid phosphatase, N-acetyl-beta-D-glucosaminidase, alpha-L-fucosidase and alpha-D-mannosidase). A prospective study was conducted of 45 endometrial biopsies obtained from women with normal menstrual cycles. Activity of all four enzymes was identified in human endometrium. Activity of acid phosphatase and N-acetyl-beta-D-glucosaminidase was relatively high, whilst that of alpha-L-fucosidase and alpha-D-mannosidase was low. There was no significant change in the activity of any of the four enzymes from the proliferative to the secretory phase of the cycle. This study suggests that the activity of these enzymes remains constant throughout a major portion of the normal cycle.

Acetylglucosaminidase↗
PubMed1997

Interferon-gamma enhances susceptibility of cervical cancer cells to lysis by tumor-specific cytotoxic T cells.

Recently we have demonstrated that tumor-specific cytotoxic T lymphocytes (CTLs) can be activated by cervical carcinoma cells expressing the costimulatory molecule CD80, which may be used as a therapeutic vaccine for patients with cervical cancer. For activated CTLs to be effective, appropriate amounts of MHC class I expression are required on target tumor cells. In this study, we found that some cervical carcinoma cells expressed only low levels of MHC class I and adhesion molecules such as CD54. We further demonstrated that tumor cells (CaSki and SiHa) expressing low levels of MHC class I were more resistant to lysis by specific CTLs than tumor cells (HeLa) expressing high levels of MHC class I. Treatment of CaSki or SiHa cells with interferon-gamma resulted in an increased expression of MHC class I, MHC class II, and CD54. Expression of CD58 and CD80 was not up-regulated or induced. Treatment of the tumor cells with interferon-gamma significantly enhanced the lysis of the tumor cells by specific CTLs which had been activated by the respective CD80-expressing tumor cells. The enhancement of cytolysis could be blocked by monoclonal antibodies to MHC class I and CD54, but not by that to MHC class II. Furthermore, we found that interferon-gamma induced apoptosis in cervical carcinoma cells but not in tumor-specific CTLs.

B7-1 Antigen↗
PubMed1997

Regulation of human papillomavirus type 18 in vivo: effects of estrogen and progesterone in transgenic mice.

We examined the in vivo effect of estrogen, progesterone, RU 486, and pregnancy on the upstream regulatory region (URR) of human papillomavirus (HPV) 18 transgenic mice. The mice contain the bacterial reporter beta-galactosidase gene under control of the HPV 18 URR. Pregnant transgenic mice were sacrificed on various days of gestation and the level of URR activation was determined. Another group of female transgenic mice was ovariectomized at 4 to 6 weeks of age. Pellets of estradiol, progesterone, progesterone + RU 486, or placebo were implanted 1 to 2 weeks after ovariectomy. Mice were sacrificed after pellet implantation to examine acute and chronic effects. Marked increases in URR activation during pregnancy were observed. Progesterone was found to activate the URR acutely. Significantly higher activation was demonstrated at 24 hr in the progesterone group compared to placebo (P < 0.01). Activation with progesterone at 24 hr was significantly higher than at any other time point (P < 0.001). A trend toward decreasing activation over time was demonstrated in the progesterone group (r = -0.87, P = 0.0001). RU 486 does not block the activation of progesterone in our model. Estradiol activates the URR acutely compared to placebo (P = 0.034). This in vivo model demonstrates activation of the URR in response to exogenous estrogen, progesterone, and pregnancy. These data may have clinical implications for women who harbor high-risk HPV.

Animals↗
PubMed1997

Special interests or citizens' rights? "Senior power," Social Security, and Medicare.

Conventional political analysts and mainstream media accounts attribute substantial political power to the elderly in the United States. This attribution of "senior power" is usually made in the context of the politics of Social Security and Medicare. This article contrasts the conventional construction of elderly political actors as a special interest with a more critical perspective that views Social Security and Medicare as citizens' rights. Critical examination of the welfare state's role in creating age as a potential political cleavage and the politics of Social Security and Medicare reveals that there is no undifferentiated politics of aging in the United States. Rather, age interacts with a variety of other statuses such as race/ethnicity, gender, and class to condition citizens' political mobilization. Welfare state policies--social insurance programs like Social Security and Medicare, means--tested programs like Medicaid and Supplemental Security Income, and targeted tax expenditures for private pensions and health insurance--differentially empower particular subgroups of elderly citizens and routinely disadvantage the most vulnerable elderly, including minority elders, women, and the oldest old.

Aged↗
PubMed1996

Expression of CD80 enhances immunogenicity of cervical carcinoma cells in vitro.

Although cervical carcinoma cells may express the human papillomavirus oncoproteins E6 and E7, they fail to induce an effective specific cytotoxic T lymphocyte response. This failure may be due to a lack of expression of costimulatory molecules, such as CD80 (B7.1). To augment the immunogenicity of cervical carcinoma cells, we transfected human papillomavirus (HPV)-transformed cell lines, CaSki and HeLa, with the CD80 expression vector pBJ. Alloantigens on the tumor cells were used for the stimulation of peripheral blood lymphocytes (PBLs). Cocultivation of PBLs and tumor cells resulted in proliferation of CD4+ and CD8+ T lymphocyte subsets. CD80-expressing tumor cells induced proliferation of allogeneic PBLs two-to sixfold compared to control cell lines. Cocultivation of allogeneic PBLs with CD80-positive tumor cells for 3 weeks gave rise to cytotoxic T cells capable of lysing untransfected parental tumor cell lines. Our results demonstrate an immunostimulatory effect of CD80 expression on cervical cancer cells, which provides a basis for the development of a therapeutic tumor vaccine.

B7-1 Antigen↗
PubMed1996

Raw shellfish consumption and warning labels: results from the 1993 Texas Behavioral Risk Factor Surveillance System (BRFSS) survey.

We used the 1993 Texas Behavioral Risk Factor Surveillance System survey to assess the prevalence of raw shellfish consumption and to find the demographic and behavioral characteristics of raw shellfish consumers. We studied the general impact of warning labels reported by survey respondents. Data were analyzed using univariate and multiple logistic regression methods. Fourteen percent of the Texas surveyed reported consuming raw shellfish. Respondents with incomes greater than or equal to $25,000 and with education beyond high school were more likely to report consuming raw shellfish than were those with incomes less than $25,000 and with high school diplomas or less. Respondents at risk for acute and chronic drinking, driving while intoxicated, and driving without a seat belt were more likely than those not at risk of these behaviors to report consumption of raw shellfish. We did not find a significant difference between eaters and noneaters of raw shellfish regarding the impact of warning labels: however, among eaters of raw shellfish, older respondents were more likely than younger respondents to report that warning labels had no effect on them.

Adolescent↗
PubMed1993

Effect of time zone and game time changes on team performance: National Football League.

To determine the effect of time zone and game time changes on NFL team performance, win-loss records from 1978-1987 were analyzed. Twenty-seven NFL teams were grouped by time zone and possible anti-jet lag adjustments. Among all intra-time zone rivals, home teams won 56.6%, away teams won 43.8%, for a home vs away winning percentage change of -12.8% (P < 0.001). West teams (N = 5) displayed fluctuations in home vs away team performance in association with trans-meridian travel. The change in winning percentage was found to be 0.0% vs West teams, -14.1% vs Central teams (N = 8) (P < 0.05), -16.3% vs East (N = 14) (P < 0.05) for West teams (N = 4) flying about 42 h pregame and +2.3% vs East for the one West team advancing practices 3-4 h to match East coast game time in addition to 48 h pregame flights. For night games within the same time zone, home vs away team winning percentage changed -23.8% (P < 0.01). West teams displayed uniformly high home winning percentages (75.0% and 68.4%) when playing Central and East teams, respectively, with little or no fall in away winning percentages (67.7% and 68.8%). For day games, a 3-h phase advance may decrease West coast team performance. In one small subset, anti-jet lag adjustments appeared to eliminate the expected decrement in performance. For night games, West coast teams, whether home or away, appear to be at a distinct advantage over East and Central teams.

Adult↗
PubMed1988

Simple ligation vs stump inversion in appendectomy.

The records of 886 patients who had appendectomy performed by the same surgeons within a five-year period were used to contrast appendiceal stump inversion vs simple ligation. Our analysis contrasted inversion vs simple ligation techniques as related to postoperative complications, hospital stay, and pathologic diagnosis. Adhesions requiring repeated operation to relieve bowel obstruction occurred in five of 87 patients with acute gangrenous appendicitis treated by inversion. Of 106 patients with acute gangrenous appendicitis treated with simple ligation, postoperative obstruction developed in none. No other statistically significant differences existed between the two techniques. These data suggest that simple ligation is at least as good as and probably better than inversion of the appendiceal stump.

Acute Disease↗
PubMed1987

Penetrating keratoplasty for pseudophakic corneal edema with exchange of intraocular lenses.

We studied one eye in each of 25 consecutive patients with pseudophakic corneal edema. Each patient underwent a penetrating keratoplasty with exchange of intraocular lenses and was followed up for 12 to 38 months (mean, 18.7 months). The corneal graft remained clear in 22 (88%) eyes, but only eight eyes (32%) had acuity of 20/40 or better; nine eyes (36%) manifested cystoid macular edema, and six eyes (24%) had degenerative maculopathy. Elevated intraocular pressure was present in 12 eyes after surgery, with three eyes manifesting visual field loss; in all eyes the condition was controlled medically. Peripheral anterior synechiae appeared postoperatively in two eyes. We now treat severe cases of pseudophakic corneal edema with a penetrating keratoplasty, meticulous anterior vitrectomy, gonioplasty, iridoplasty, and exchange of intraocular lenses, employing a flexible-loop anterior chamber lens or a posterior chamber lens sutured to the iris.

Adult↗
PubMed1987

Nutritional status of middle-aged and elderly females in Kentucky in two seasons: Part 1. Body weight and related factors.

Middle-aged and elderly females aged between 51 and 86 years volunteered for this study. In June and July, 147 females were studied; data collected through interview included general socioeconomic information, health history, use of medication, and a 7-day food intake. During the same 7-day period, physical activity level was measured for each person by use of a pedometer. On the 8th day, anthropometric measurements were conducted and fasting blood was analyzed for certain hormones and related metabolites. In the following January and February, the same group was surveyed again and the same measurements were repeated. Of the initial 147 subjects, 130 persons completed the winter survey. A comparison of the summer and winter data indicated some significant differences: mean body weight increased in winter from 70.4 +/- 12.7 to 71.1 +/- 13.5 kg (p less than or equal to 0.05); energy intake was raised from 1450 +/- 384 to 1549 +/- 372 kcal (p less than or equal to 0.01); physical activity decreased from 10.9 +/- 8.2 to 8.5 +/- 5.4 miles/week (p less than or equal to 0.01); and serum free thyroxine (T4) fell from 1.72 +/- 0.27 to 1.64 +/- 0.27 ng/dl. These results together with other data suggest that more attention should be addressed to seasonal fluctuations involved in body weight maintenance.

Aged↗
PubMed1984

Tympanometric changes following nasal antigen challenge in children with allergic rhinitis.

Intranasal antigen provocation was used to study the relationship between allergic rhinitis and changes in middle ear pressure. Middle ear pressure was measured by tympanometry and nasal airway resistance by anterior rhinomanometry. Middle ear pressure became significantly more negative following antigen challenge as compared with control challenge. A subgroup of patients showed middle ear pressure changes of more than minus 50 mm water. This pressure change was rapid and was associated with increased nasal symptoms. These results indicate a role for allergy in the development of negative middle ear pressure, a key finding in otitis media with effusion.

Acoustic Impedance Tests↗
PubMed1980

Male admissions to the English Special Hospitals--1961-1965: a demographic survey.

The social, criminal and psychiatric backgrounds of 878 male patients admitted for the first time to the three English Special Hospitals during the years 1961-1965 are examined and the implications of differences between them for research discussed. It is noted that only 35 per cent of the admission group have been discharged within a four year period. The need for long term follow-up studies is stressed.

Adult↗