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Biomedical subjects

P Friedmann

Publications and source records attributed to P Friedmann.

At least 37 records · Page 2Linked to original sources
PubMed1997

A prospective comparison of two expanded polytetrafluoroethylene grafts for linear forearm hemodialysis access: does the manufacturer matter?

BACKGROUND: The function and patency of standard 6-mm Goretex (W.L. Gore and Associates, Flagstaff, AZ) and Impra (Impra, Inc., Tempe, AZ) expanded polytetrafluoroethylene (e-PTFE) grafts for hemodialysis as radial-antecubital linear arteriovenous fistulae for dialysis are compared. STUDY DESIGN: A randomized clinical trial was conducted in two community dialysis centers and in one hospital-based center serviced by one vascular surgical practice, that performed the access surgery. Selection of linear forearm access, as opposed to other hemodialysis graft configurations, was at the discretion of the surgeon. Candidates for linear grafts had palpable radial pulses with a normal Allen test and normal digital Doppler flow in the hand. Linear grafts were placed using end-to-side anastomoses to the artery and vein, and the graft type was determined by randomization. Primary patency was determined by first episode of thrombosis, first revision, or angioplasty of the graft. Secondary patency after thrombectomy, revision, or angioplasty was determined when the graft was no longer clinically usable, and a new graft needed to be placed as a parallel conduit in the forearm or in another site. Statistical analysis was by actuarial life-table methods. RESULTS: There were 131 linear forearm grafts in 117 patients. The Impra and Goretex groups were equally matched for gender and major risk factors, except for smoking, which was more common in the Goretex group. Minimum followup was 24 months. Life table primary patencies at 1 year (Impra 43%, Goretex 47%) and at 2 years (Impra 30%, Goretex 26%) were not statistically different (p = 0.78); secondary patency was also equal at 1 year (Impra 49%, Goretex 69%) and at 2 years (Impra 33%, Goretex 41%) (p = 0.15). Discontinuance of use of a patent graft, complications, episodes of thrombosis, and the need to replace the original graft occurred in the two groups without a statistically significant difference. CONCLUSIONS: In the linear forearm position from the radial artery to an antecubital vein, there is no difference in the performance of 6-mm standard e-PTFE grafts on the basis of manufacturer, whether Goretex or Impra. On the basis of performance, linear forearm dialysis grafts are an acceptable method for hemodialysis access.

Adult↗
PubMed1996

Feasibility and safety of 1-day postoperative hospitalization for carotid endarterectomy.

OBJECTIVE: To determine whether 1-day postoperative hospitalization after carotid endarterectomy is safe and the degree to which this can be achieved. DESIGN: Consecutive sample series of all carotid endarterectomies performed by a single surgical group. SETTING: A single tertiary-care hospital. PATIENTS: All who underwent carotid endarterectomy. Patients with procedures combined with coronary revascularization and patients undergoing the first part of a staged bilateral carotid endarterectomy performed in 1 hospitalization were excluded. INTERVENTION: In December 1993, a fast-track protocol was initiated, aiming for a 1-day stay after carotid endarterectomy without admission to an intensive care unit (ICU). Before this date, postoperative care included obligatory monitoring for at least 1 night in an ICU. MAIN OUTCOME MEASURES: Length of stay, admission to and stay in the ICU, complications, and hospital readmission rate. RESULTS: Over a 21-month period, 152 patients had 163 carotid endarterectomies. Of these, 124 were elective and 39 urgent (patients with a critical stenosis). Indications were stroke (n = 14 [8.6%]), transient ischemic attack (n = 50 [30.7%]), amaurosis fugax (n = 36 [22.1%]), and asymptomatic stenosis (n = 63 [38.7%]). General anesthesia was used for 159 procedures, cervical block for 4. Mean operation time was 2.6 hours. Postoperative stay was 1 day for 82 procedures (50%), 2 days for 49 procedures (30%), 3 days for 12 procedures (7%), and longer for 20 procedures (12%). In the last half of the study, 61% of patients (50/82) were discharged on postoperative day 1 and 87% (71/82) by postoperative day 2. One hundred three patients went to a surgical floor postoperatively. Overall, 60 patients went to the ICU, but only 18 (22%) of the last 82 procedures required ICU admission. The total stay averaged 3.8 days. Twenty-one patients (13%) experienced complications, including 3 deaths within 30 days and 5 neurological deficits. There were 14 early readmissions, but none was attributable to discharge on the first or second postoperative day. CONCLUSIONS: Early discharge home after carotid endarterectomy is safe and efficacious, and obligatory admission to an ICU is not necessary. At least 60% of patients who undergo carotid endarterectomy can have a postoperative stay of 1 day, and more than 80% can be discharged by postoperative day 2. A short postoperative stay is not associated with a significant risk of readmission for complications.

Adult↗
PubMed1996

The protective effect of AIDS-related behavioral change among injection drug users: a cross-national study. WHO Multi-Centre Study of AIDS and Injecting Drug Use.

OBJECTIVE: This study assessed the relationship between self-reported acquired immunodeficiency syndrome (AIDS) behavioral change and human immunodeficiency virus (HIV) serostatus among injection drug users. METHODS: The study sample involved 4419 injection drug users recruited from drug abuse treatment and nontreatment settings in 11 cities in North America, South America, Europe, Asia, and Australia. The World Health Organization multisite risk behavior questionnaire was used, and either blood or saliva samples for HIV testing were obtained. Subjects were asked, "Since you first heard about AIDS, have you done anything to avoid getting AIDS?" RESULTS: The protective odds ratio for behavioral change against being infected with HIV was 0.50 (95% confidence interval = 0.42, 0.59). While there was important variation across sites, the relationship remained consistent across both demographic and drug use history subgroups. CONCLUSIONS: Injection drug users are capable of modifying their HIV risk behaviors and reporting accurately on behavioral changes. These behavioral changes are associated with their avoidance of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1996

[10 year results of preoperative radiotherapy in treatment of rectal carcinoma].

BACKGROUND: We have previously reported improvements in survival and disease-free survival at five years using preoperative radiation in the treatment of rectal cancer. The current update was undertaken to determine if these favorable results were durable with longer follow-up. METHODS: Patients found to have resectable rectal cancer between 1972 and 1979 were treated with 40-45 Gy of preoperative radiation (40 patients) or resection alone (109 patients). Follow-up information beyond five years was obtained from the Tumor Registry, physician contact and a survey of the National Death Index. Of the 149 patients followed for five years, 144 were evaluable at ten years. RESULTS: After a median follow-up of 125 months, survival of the irradiated patients was significantly better than that of controls (77 versus 57% at 5 years and 74 versus 41% at 10 years, p = 0.0044). Disease-free survival of those patients whose resection margins were free was also superior for the irradiated group (85 versus 59% at 5 years and 80 versus 45% at 10 years, p = 0.0045). CONCLUSIONS: The results show that the survival advantage for 40 to 45 Gy preoperative radiation in the treatment of rectal cancer persist at 10 years follow-up.

Cobalt Radioisotopes↗
PubMed1995

Maintaining low HIV seroprevalence in populations of injecting drug users.

OBJECTIVES: To describe prevention activities and risk behavior in cities where human immunodeficiency virus (HIV) was introduced into the local population of injecting drug users (IDUs), but where seroprevalence has nevertheless remained low (< 5%) during at least 5 years. DESIGN AND SETTING: A literature search identified five such cities: Glasgow, Scotland; Lund, Sweden; Sydney, New South Wales, Australia; Tacoma, Wash; and Toronto, Ontario. Case histories were prepared for each city, including data on prevention activities and current levels of risk behavior among IDUs. PARTICIPANTS: Injecting drug users recruited from both drug treatment and non-treatment settings in each city. INTERVENTIONS: A variety of HIV prevention activities for IDUs had been implemented in each of the five cities. RESULTS: There were three common prevention components present in all five cities: (1) implementation of prevention activities when HIV seroprevalence was still low, (2) provision of sterile injection equipment, and (3) community outreach to IDUs. Moderate levels of risk behavior continued with one third or more of the IDUs reporting recent unsafe injections. CONCLUSIONS: In low-seroprevalence areas, it appears possible to severely limit transmission of HIV among populations of IDUs, despite continuing risk behavior among a substantial proportion of the population. Pending further studies, the common prevention components (beginning early, community outreach, and access to sterile injection equipment) should be implemented wherever populations of IDUs are at risk for rapid spread of HIV.

HIV Infections↗
PubMed1995

Predictors and outcome of multidrug-resistant tuberculosis.

We identify early predictors of multidrug-resistant tuberculosis and describe improved clinical outcomes, including survival, for patients with human immunodeficiency virus (HIV)-related multidrug-resistant tuberculosis (MDR-TB) when they are prospectively identified and receive treatment under direct observation. Analysis by means of a Cox proportional hazards model revealed that failure to defervesce while receiving a standard four-drug antituberculous regimen was independently associated with multidrug resistance (P = .004). When patients with HIV-related MDR-TB were prospectively identified and treated with at least two agents that were active in vitro, 100% bacteriologic conversion and improved survival (> or = 4 months for 88% of patients and > or = 1 year for 59% of patients) were observed. For patients with HIV-related tuberculosis, poorer survival was associated with a CD4+ lymphocyte count of < 25 mm3 (P = .03); multidrug resistance was not a predictor of poor outcome (P = .82). These data suggest that patients with prolonged fever who are receiving antituberculous therapy may be an appropriate subgroup to target for broader empirical therapy. The findings also demonstrate that improved outcomes can be achieved with HIV-related MDR-TB when patients are prospectively identified and treated with agents that are active in vitro.

AIDS-Related Opportunistic Infections↗
PubMed1995

HIV/AIDS-related behavior change among injecting drug users in different national settings.

OBJECTIVES: To identify factors associated with effective AIDS behavior change among injecting drug users (IDU) in different national settings. DESIGN: Cross-sectional surveys of IDU, with determination of HIV status. Trends in city HIV seroprevalence among IDU also used to validate effectiveness of behavior change. SETTING AND PARTICIPANTS: Subjects recruited from drug-use treatment programs and outreach efforts in Bangkok, Thailand (n = 601), Glasgow, Scotland (n = 919), New York City, USA (n = 2539), and Rio de Janeiro, Brazil (n = 466). RESULTS: Evidence for the effectiveness of self-reported risk reduction was available for all cities. Univariate followed by multiple logistic regression analyses were used to identify factors associated with self-reported AIDS behavior change. Separate analyses were conducted for each city. Talking about AIDS with drug-using friends was significantly associated with behavior change in all four cities. Talking with sex partners about AIDS, educational level, knowing that someone can be HIV-infected and still look healthy, and having been tested previously for HIV were each significantly associated with behavior change in three of the four cities. CONCLUSIONS: Despite the substantial differences in these national settings, there were common factors associated with effective risk reduction. In particular, risk reduction appears to occur through social processes rather than through individual attitude change. HIV prevention programs need to explicitly incorporate social processes into their work.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Synergistic effect of basic fibroblast growth factor and methylprednisolone on neurological function after experimental spinal cord injury.

The authors evaluated the effects of exogenous basic fibroblast growth factor (bFGF) in combination with intravenous methylprednisolone on neurological function and cord angiogenesis in a model of spinal cord injury. Cord injury was produced by extradural clip compression through a T-1 laminectomy. Rats were randomized to one of six groups. Group A was given sham laminectomy without cord injury or treatment. The remaining animals were divided into five groups: untreated injury (Group B); injury treated with methylprednisolone (Group C); combined methylprednisolone and 1 microgram bFGF administered locally at the site of injury (Group D); methylprednisolone and 3 micrograms bFGF (Group E); or methylprednisolone and 3 micrograms heated bFGF (Group F). Groups C through F received treatment 1 hour after cord injury. At 1, 2, 3, and 4 weeks after surgery, neurological function of hindlimbs was assessed by blinded observers using an established multiple test method (toe spread, reflexes to extension, pain, and pressure as well as inclined plane and swim test) with tests graded and results expressed as a combined behavioral score. Animals were killed to study spinal cord angiogenesis in cord samples (2-mm sections proximal and distal to the injury site) by capillary density determination. Behavioral scores over time showed a significant difference among Groups B, C, D, E, and F (p = 0.0044), with Groups E and B maintaining highest and lowest scores, respectively. There was a linear dose effect of bFGF over time (p = 0.0187). At 4 weeks, scores showed a difference among the five groups (p = 0.006), with Group E showing higher scores than any other treatment group (for example, vs. group F: p = 0.035). There was a significant difference among the groups in gray matter capillary density counts: proximal (p = 0.0192) and distal (p = 0.024), whereas white matter capillary counts were similar across treatment groups. These results show: 1) possible synergism exists between methylprednisolone and bFGF, such that combinations of these drugs significantly enhance neurological recovery, 2) bFGF exhibits a dose-response effect in function but not in capillary density, and 3) heated, inactivated bFGF is not therapeutically effective.

Analysis of Variance↗
PubMed1994

Predictors of axillary lymph node metastases in patients with T1 breast cancer. A multivariate analysis.

BACKGROUND: In T1 tumors, the reported incidence of lymph node metastases ranges from 21% to 35%. The authors analyzed the pathology parameters of T1 tumors for their association with the likelihood of axillary lymph node metastases. METHODS: Two hundred sixty-three patients with T1 unilateral invasive breast cancer were studied. All underwent axillary dissection, and the pathologic status of the nodes was known. The parameters of the primary tumor evaluated included size, histologic subtype, nuclear grade, DNA ploidy, S-phase fraction (SPF), hormone receptor status, lymphatic/vascular invasion (LVI), and host reaction. RESULTS: Seventy-two (27%) patients had nodes that were positive for metastasis. Univariate analysis showed that lymph node metastases were associated with tumors larger than 1 cm (P = 0.001), moderate or poorly differentiated nuclear grade (P = 0.005), high SPF (P = 0.041), presence of LVI (P < 0.001) and patients younger than 60 years (P = 0.01). However, independent predictors of lymph node metastasis in the multivariate logistic regression analyses were tumor size and LVI. Twenty-five patients had tumors larger than 1.0 cm and presence of LVI; of these, 17 (68%) had lymph node metastases. Of the 79 patients who had neither of these features, only 7 (9%) had lymph node metastases. CONCLUSIONS: The authors conclude that characteristics of the primary tumor can help assess the risk for axillary lymph node metastases. Selected patients who are assessed to be at minimal risk might be spared routine axillary dissection or radiation therapy to the axilla.

Adult↗
PubMed1994

Risk factors for HIV-1 seroprevalence among drug injectors in the cocaine-using environment of Rio de Janeiro.

To determine risk factors for HIV-1 among drug injectors in Rio de Janeiro, where cocaine is the dominant drug of injection, subjects were recruited using the criteria and interview instrument of the World Health Organization's Cross-National Study of HIV infection and risk behaviour in injecting drug users. HIV antibody test results were derived both from serum tests and from self-reports of previous tests (documented evidence of self-reported seropositivity was required). The analytical sample consists of 123 subjects, recruited both at drug abuse treatment sites and at street locations. Of 27 subjects with both serological and self-reported antibody status data, 20 reported previous negative tests; of these three had positive sera and may have seroconverted. Seven subjects reporting prior positive serostatus all tested positive. For the 123 subjects, seroprevalence was 34%. Independent significant risk factors in multivariate logistic regression with backwards elimination are: years of injection greater than 5; being a male who has had sex with men in the previous 5 years; and not having taken deliberate steps to protect oneself against AIDS. These findings indicate that homosexual/bisexual male drug injectors may be a bridge group through which HIV is entering drug-injecting networks in Rio de Janeiro. Efforts by drug injectors to reduce their risk of infection seem to have protective effects. This underscores the importance of HIV prevention efforts aimed at drug injectors.

Brazil↗
PubMed1994

AIDS risk reduction and reduced HIV seroconversion among injection drug users in Bangkok.

Human immunodeficiency virus (HIV) seroconversion was studied in a group of 173 injection drug users in Bangkok, Thailand, who had been previously tested for HIV and were interviewed and retested in the fall of 1989. Ten percent of the group had seroconverted. Two factors protected against HIV seroconversion: having stopped sharing injection equipment in response to the acquired immunodeficiency syndrome (AIDS) and having a regular sexual partner. The association between self-reported deliberate risk reduction and reduced HIV seroconversion among persons continuing to inject illicit drugs indicates that injection drug users can change their behavior in response to AIDS and will accurately report on the behavior change, and that the changes can protect against HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Condom use with primary partners among injecting drug users in Bangkok, Thailand and New York City, United States.

OBJECTIVE: To determine factors associated with likelihood or failure to use condoms with primary sexual partners among injecting drug users (IDU) in two cities. DESIGN AND METHODS: Interviews were conducted with 601 IDU in Bangkok in 1989 and with 957 IDU in New York City in 1990-1991. Subjects were recruited from drug-use treatment programs and a research storefront. Informed consent was obtained and a World Health Organization standardized questionnaire about AIDS risk behaviors administered by a trained interviewer. RESULTS: A substantial minority (37%) of IDU in Bangkok and a majority (55%) of IDU in New York City reported penetrative intercourse (vaginal, anal or oral) with a primary partner in the 6 months before the interview. Of those reporting penetrative intercourse with a primary partner, only 12% in Bangkok and 20% in New York reported that they always used condoms. Parallel bivariate and multiple logistic regression analyses were conducted to distinguish between subjects who reported always using condoms and subjects who reported unsafe sexual activity with primary partners. The same two factor--knowing that one is HIV-seropositive and talking about AIDS with sexual partners--were most strongly associated with always using condoms with primary partners in both cities. CONCLUSIONS: Programs to prevent sexual transmission of HIV among IDU should provide voluntary and confidential/anonymous HIV counseling and testing, and should facilitate discussions of AIDS and sexual transmission of HIV between IDU and their sexual partners. That the same two factors were associated with always using condoms with primary partners among IDU in these two cities suggests that these factors may also be important in other groups at high risk for HIV.

Adult↗
PubMed1993

Relationship between maternal methadone dosage, maternal-neonatal methadone levels, and neonatal withdrawal.

OBJECTIVE: To define the relationships between neonatal opiate withdrawal and drug-related factors such as maternal methadone dosage, maternal and neonatal plasma levels, and rate of decline of methadone in neonatal plasma. METHODS: Twenty-one methadone-dependent women and their newborn infants were studied. Fourteen of the women used other illicit drugs. The severity of neonatal withdrawal was assessed with a standardized scoring system. Venous blood samples for methadone levels were collected from the mothers within 24 hours of delivery and from their newborns within 24 hours of birth and on day 3-4 of life. RESULTS: The maternal methadone dosage at delivery correlated significantly with the maternal plasma level drawn at 16 hours postpartum (r = 0.512, P < .05), and the maternal methadone level in turn correlated significantly with the neonatal plasma methadone level on day 1 of life (r = 0.545, P < .05). A positive correlation was found between the severity of central nervous system signs of withdrawal and the rate of decline of the neonatal plasma methadone level from day 1 to day 4 of life (r = 0.550, P < .05). CONCLUSION: This spectrum of relationships supports the concept that careful reduction of the maternal methadone dosage during pregnancy under intensive medical and psychosocial surveillance may benefit the drug-exposed new-born infant clinically.

Female↗