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Biomedical subjects

D Glasser

Publications and source records attributed to D Glasser.

At least 19 recordsLinked to original sources
PubMed2006

Efficiency of polymer beads in the removal of heparin: toward the development of a novel reactor.

Administration of heparin during extracorporeal procedures increases the risk of haemorrhage. Various reactor designs, including the use of heparinase and poly-L-lysine. HBr hollow fiber, have been investigated for the removal of heparin prior to the blood being returned to the patient; however, none of them have been implemented clinically. In this paper it is proposed that beads made from poly-L-lysine/alginate can be used to remove the heparin. The aim of this work is to perform the necessary experiments in order to get the information required to design a heparin removal reactor that uses these beads. The experiments are aimed at measuring the removal rates of heparin by the beads, testing the efficiency of the beads to remove heparin, determining repeatability and identifying factors that could influence the removal rate. Batch rate experiments using poly-L-lysine/alginate beads in saline solutions were performed to investigate the removal rate of heparin. The results, which indicate that heparin is efficiently removed, may lead to improved bioreactor designs.

Alginates↗
PubMed2004

The sexual habits of British men and women over 40 years old.

OBJECTIVE: To obtain a greater understanding of sexual behaviour and habits among men with and without erectile dysfunction (ED), and their female partners, to improve the management of ED in heterosexual men. SUBJECTS AND METHODS: A population-based study was conducted amongst men and women aged > 40 years. None of the subjects were partners in the same sexual relationship. Interviews were conducted on the Internet via a panel-based questionnaire. RESULTS: In all, 225 (32%) men had self-reported ED and 88 (26%) women reported that their partner had ED. For all men (with or without ED) the mean time from first thinking of intercourse to beginning intercourse was just under 1 h. During their most recent period of sexual activity, 87% of men with and 78% of men without ED had intercourse with ejaculation at most once within 24 h; 81% of men and 89% of women felt that it was neither very nor extremely important to have intercourse with ejaculation more than once in a 24-h period. CONCLUSIONS: This study reports for the first time the frequency of sexual activity in British men and women in heterosexual relationships, and describes the usual timings of sexual events. Few significant differences were identified between men with or with no ED.

Adult↗
PubMed2002

Psychotherapy for sexually abused girls: psychopathological outcome findings and patterns of change.

BACKGROUND: Controversy exists about the efficacy of psychotherapy for the mental health problems of sexually abused children. AIMS: To compare the relative efficacy of focused individual or group therapy in symptomatic sexually abused girls, and to monitor psychiatric symptoms for persistence or change. METHOD: A multi-centre psychotherapy outcome study recruited 71 sexually abused girls aged 6-14 years who were randomly assigned to focused individual psychotherapy (up to 30 sessions) or psychoeducational group therapy (up to 18 sessions). Changes over the course of the study were monitored. RESULTS: Both treatment groups showed a substantial reduction in psychopathological symptoms and an improvement in functioning, but with no evident difference between individual and group therapy. However, individual therapy led to a greater improvement in manifestations of post-traumatic stress disorder (PTSD). CONCLUSIONS: The beneficial effects on PTSD support the use of individual therapy. However, the small sample size and lack of a control group limit conclusions about changes attributable to treatment.

Adolescent↗
PubMed2001

Prevalence and determinants of erectile dysfunction in hemodialysis patients.

BACKGROUND: The prevalence of erectile dysfunction (ED) among patients with end-stage renal disease (ESRD) is not known. METHODS: A cross-sectional study was conducted to determine the prevalence of ED among a community-based hemodialysis (HD) population using a two-stage cluster random sampling design. The presence and severity of ED were assessed among 302 ESRD patients using the self-administered International Index of Erectile Function-5 (IIEF-5). Logistic regression was used to examine and test associations between ED and other medical conditions. RESULTS: The prevalence of any level of ED was 82% (95% CI, 76 to 87%) for all HD subjects. The prevalence of severe ED was 45% (CI, 36 to 55%). Subjects younger than 50 years had a prevalence of ED of 63% (CI, 53 to 71%), while in subjects 50 years or older, it was 90% (CI, 84 to 94%). A multivariable analysis demonstrated increasing age (50 to 59, OR = 2.04, 95% CI, 1.3 to 3.1; 60 to 69, OR = 5.5, 95% CI, 1.9 to 15.6) and diabetes (OR = 2.0, 95% CI, 1.2 to 3.3) to be independently associated with the presence of any level of ED. However, neither the subjects' age nor history of diabetes predicted the severity of ED among subjects with ED. The use of angiotensin-converting enzyme inhibitors (ACEIs) was inversely associated with ED (OR = 0.41, 95% CI, 0.17 to 0.98). Poor functional status (Karnofsky score or the Index of Physical Impairment) was not associated with ED. CONCLUSIONS: ED is extremely prevalent among HD patients. Increasing age, diabetes, and nonuse of ACEIs were associated with higher prevalence of ED. The high prevalence of ED was seen even among patients with good functional status.

Adult↗
PubMed1998

Effect of film-based versus filmless operation on the productivity of CT technologists.

PURPOSE: To determine the relative time required for a technologist to perform a computed tomographic (CT) examination in a "filmless" versus a film-based environment. MATERIALS AND METHODS: Time-motion studies were performed in 204 consecutive CT examinations. Images from 96 examinations were electronically transferred to a picture archiving and communication system (PACS) without being printed to film, and 108 were printed to film. The time required to obtain and electronically transfer the images or print the images to film and make the current and previous studies available to the radiologists for interpretation was recorded. RESULTS: The time required for a technologist to complete a CT examination was reduced by 45% with direct image transfer to the PACS compared with the time required in the film-based mode. This reduction was due to the elimination of a number of steps in the filming process, such as the printing at multiple window or level settings. CONCLUSION: The use of a PACS can result in the elimination of multiple time-intensive tasks for the CT technologist, resulting in a marked reduction in examination time. This reduction can result in increased productivity, and, hence greater cost-effectiveness with filmless operation.

Analysis of Variance↗
PubMed1995

An anatomic and physiological model of hepatic vascular system.

Hepatic function can be characterized by the activity/time curves obtained by imaging the aorta, spleen, and liver. Nonparametric deconvolution of the activity/time curves is clinically useful as a diagnostic tool in determining organ transit times and flow fractions. The use of this technique is limited, however, because of numerical and noise problems in performing deconvolution. Furthermore, the interaction of part of the tracer with the spleen and gastrointestinal tract, before it enters the liver, further obscures physiological information in the deconvolved liver curve. In this paper, a mathematical relationship is derived relating the liver activity/time curve to portal and hepatic behavior. The mathematical relationship is derived by using transit time spectrum/residence time density theory. Based on this theory, it is shown that the deconvolution of liver activity/time curves gives rise to a complex combination of splenic, gastrointestinal, and liver dependencies. An anatomically and physiologically plausible parametric model of the hepatic vascular system has been developed. This model is used in conjunction with experimental data to estimate portal, splenic, and hepatic physiological blood flow parameters for eight normal volunteers. These calculated parameters, which include the portal flow fraction, the splenic blood flow fraction, and blood transit times are shown to adequately correspond to published values. In particular, the model of the hepatic vascular system identifies the portal flow fraction as 0.752 +/- 0.022, the splenic blood flow fraction as 0.180 +/- 0.023, and the liver mean transit time as 13.4 +/- 1.71 s. The model has also been applied to two portal hypertensive patients. The variation in some of the model parameters is beyond normal limits and is consistent with the observed pathology.

Blood Flow Velocity↗
PubMed1993

Osteoid osteoma of the upper extremity.

Forty-six patients with histologically confirmed osteoid osteoma of the upper extremity seen from 1947 to 1990 were retrospectively reviewed. The patients' age at presentation averaged 20 years. Twenty-four of the lesions were located in the wrist and hand and 22 in the arm and forearm. The average duration of symptoms before diagnosis was 15 months. Pain was the presenting symptom in 44 of 46 patients. Of the 28 patients who took aspirin for pain, 24 obtained at least partial relief. A mass or swelling was more commonly noted in lesions of the hand and wrist as compared to the arm and forearm. The diagnosis of osteoid osteoma was made by plain x-ray films alone in 35 cases. Bone scans were performed on 13 patients; all were positive at the site of the lesion. Tomography was performed in 13 cases to identify the intraosseous location of the lesion. All lesions were treated by excision and curettage. Thirty-four of the 46 patients were followed at our institution for more than 6 months, with an average follow-up period of 27 months. Six of the patients had persistent lesions. Of the six persistent osteoid osteomas, five occurred in the wrist or hand (p = .0012). A total of 15 procedures were required to excise these lesions.

Adolescent↗
PubMed1992

Herpes simplex virus infection as a risk factor for human immunodeficiency virus infection in heterosexuals.

To determine if infection with herpes simplex virus (HSV) type 2 is associated with human immunodeficiency virus (HIV) type 1 infection among patients attending sexually transmitted diseases clinics, a case-control study was done on coded sera from 179 HIV-1-infected patients and 367 age-, race-, and gender-matched HIV-1-seronegative patients. Although only 13 (2.3%) of 546 patients had a history of genital herpes treatment, 72% and 56.6%, respectively, had serologic evidence of prior infection with HSV-1 and -2. HSV-1 antibody prevalence was similar among both patient groups; however, HSV-2 antibodies were more common among those infected with HIV-1. Among heterosexual men, 62.7% of those infected with HIV-1 had HSV-2 antibodies compared with 46.7% of those not infected (P less than .01). The HSV-2 seroprevalence among women with or without HIV infection was 78.1% and 57.7%, respectively (P less than .02). A history of intravenous drug use and a reactive serologic test for syphilis were each independently associated with HIV-1 infection in heterosexuals. These data suggest that the two most common causes of genital ulcerative disease in the United States, genital herpes and syphilis, may contribute to increased risk for HIV-1 infection among heterosexuals.

Antibodies, Viral↗
PubMed1990

The association of syphilis with risk of human immunodeficiency virus infection in patients attending sexually transmitted disease clinics.

A serologic survey of 4863 patients attending two inner-city sexually transmitted disease clinics was conducted in 1988 1 year after an initial survey to reassess the prevalence and associated risk factors for human immunodeficiency virus (HIV) infection. The HIV seroprevalence rates had not changed significantly (5.2% in 1987, 4.9% in 1988), and remained higher among men (5.6%) than among women (3.6%). The HIV seroprevalence increased steadily with age, to 34 years in women and to 39 years in men. Of patients with a reactive syphilis serologic test result, 24.3% were HIV infected compared with 3.5% of patients with a nonreactive test for syphilis. In multivariate analysis, a reactive serologic test for syphilis was significantly associated with HIV infection in all major risk behavior categories. Among heterosexuals who denied parenteral drug abuse, HIV infection rates were 6.8 and 8.7 times greater for women and men, respectively, who had a reactive serologic test for syphilis. Evidence of heterosexual transmission of HIV was further suggested by a change in HIV seroprevalence in women from 3.0% in 1987 to 3.6% in 1988, a male to female HIV infection ratio of 1.6, and 3.0% prevalence of infection among patients who denied established risk factors. This was most evident among those younger than 25 years, in whom 72% of infected women and 46.2% of infected men denied high-risk behaviors. These data demonstrate the strong association between syphilis and HIV infection and the importance of heterosexual HIV transmission in patients attending sexually transmitted disease clinics. This study underscores the need for a more comprehensive control program for sexually transmitted diseases, including syphilis and HIV infection.

Adolescent↗
PubMed1989

HIV infection rates in a trauma center treating predominantly rural blunt trauma victims.

Human immunodeficiency virus (HIV) infection rates among 1,497 consecutive adult trauma victims triaged from rural and urban sectors to a statewide trauma center in Baltimore were studied. Those studied were 71.7% men, 77.4% whites, 63.2% vehicular trauma victims, 11.2% assault victims, and 25.7% other trauma victims. Non-Baltimoreans predominated (86.0%) and 32.7% were 25 to 39 years of age. Overall, 1.67% of the victims were HIV antibody positive. Significantly higher infection rates were seen in men (1.96% vs. 0.95%; p less than 0.02), non-whites (4.13% vs. 0.95; p less than 0.005), assault victims compared with vehicular and other trauma victims (5.99% vs. 1.06% vs. 1.30%, respectively; p less than 0.001), and Baltimore City residents (3.81% vs. 1.32%; p less than 0.03). Among those 25 to 39 years of age, 68.0% of the HIV infections were noted. Results suggest that HIV infection rates among trauma center patients are a reflection of the patient population served.

Adolescent↗
PubMed1989

Prevalence of risk behaviors and HIV infection in Maryland STD clinics.

Persons who are receiving evaluation and treatment for sexually transmitted diseases are at moderately increased risk for acquiring HIV infections. The scope of STD clinic services should be broadened to include counseling, education, and referral services for health needs related to risk of HIV infection.

Adolescent↗
PubMed1988

Human immunodeficiency virus infection among patients attending clinics for sexually transmitted diseases.

To assess the prevalence and associated risk factors for human immunodeficiency virus (HIV) infection in patients attending inner-city clinics for sexually transmitted diseases in Baltimore, we screened 4028 patients anonymously, of whom 209 (5.2 percent) were seropositive for HIV. HIV-seropositivity rates were higher among men (6.3 percent) than women (3.0 percent) (P less than 0.001) and among blacks (5.0 percent) than whites (1.2 percent) (P less than 0.02). Among men, but not women, HIV seroprevalence increased markedly and steadily up to the age of 40. In men, HIV seropositivity was independently associated with increased age, black race, a history of homosexual contact, and the use of parenteral drugs. In women, a history of parenteral drug use or of being a sexual partner of a bisexual man or parenteral drug user were independently predictive of HIV seropositivity. In men, HIV seropositivity was also associated with a history of syphilis or a reactive serologic test for syphilis, and in women, with a history of genital warts. Since these associations were independent of the type and number of reported sexual partners, they raise the possibility that sexually transmitted diseases that disrupt epithelial surfaces may be important in the transmissibility of HIV. In addition, on a self-administered questionnaire, one third of HIV-infected men and one half of infected women did not acknowledge previous high-risk behavior for HIV exposure. These data suggest that patients at clinics for sexually transmitted diseases represent a group at high risk for HIV infection, and that screening, counseling, and intensive education should be offered to all patients attending such clinics.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Evidence of human infection with a rat-associated Hantavirus in Baltimore, Maryland.

Human sera obtained from two sources in Baltimore were tested for antibodies against a Hantavirus by a variety of techniques. Four persons out of 1,788 had hantaviral antibody as demonstrated by immunofluorescent assay, enzyme-linked immunosorbent assay, and neutralizing assay. Neutralizing antibody titrations against three test viruses indicated that infections were caused by a rat-associated virus. Medical histories of two subjects indicated life-long residence in Baltimore and an absence of foreign travel, implicating a local source of infection.

Adolescent↗
PubMed1987

Contraceptive needs and practices among women attending an inner-city STD clinic.

To assess the potential need, interest, and benefits of provision of contraceptive services in sexually transmitted disease (STD) clinics, we surveyed 516 women attending an inner-city STD clinic regarding contraceptive and sexual practices, STD prevalence, knowledge of contraceptive-related STD prophylaxis, and interest in contraceptive services within the STD clinic setting. The study population was at high risk for unintended pregnancy and STDs; at time of interview 46 per cent of women were not contracepting and 59 per cent were treated for STD or STD exposure. Two-thirds of women had at least one prior pregnancy and 50 per cent had at least one living child. Only 26 per cent of women knew that some contraceptive methods may reduce the risk of STD acquisition; however, 62 per cent expressed interest in contraceptive methods which would reduce their risk of STD acquisition. This study suggests that provision of contraceptive services in STD clinic settings may address dual needs in a group at high risk for both unintended pregnancy and STD.

Adolescent↗
PubMed1986

Binding isotherms by continuous-flow dynamic dialysis.

The classical dynamic dialysis technique for the determination of a protein-ligand binding isotherm has been modified by the introduction of a flow cell in which the dialysate on the sink side of the membrane is continuously eluted with a constant flow of eluting buffer and its ligand concentration measured. This new experimental method is termed continuous-flow dynamic dialysis (CFDD). A transfer function procedure for extracting the binding isotherm from the dialysis data is described. This is a more general technique (requiring only a verifiable assumption of linearity) than that previously used, in which the system was modelled using Fick's first law and which relied on the establishment of quasi-steady state conditions across the membrane. The present analysis uses the Laplace transform to effect deconvolution of the impulse response function of the cell from the dialysis data and, using a Fourier series approach, directly yields numerical data representing the free ligand concentration in equilibrium with the protein-ligand complex. The protein-ligand binding isotherm is obtained in parametric form, with time as the parameter.

Journal Article↗