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Biomedical subjects

S Kleinman

Publications and source records attributed to S Kleinman.

At least 19 recordsLinked to original sources
PubMed2004

Comparison of demographic and donation profiles and transfusion-transmissible disease markers and risk rates in previously transfused and nontransfused blood donors.

BACKGROUND: Increasing concern about transfusion transmission of variant Creutzfeldt-Jakob disease has resulted in indefinite deferral of transfused donors in France and the UK. Little is known, however, about the impact of indefinite deferral of transfused donors on blood safety and availability in the US. STUDY DESIGN AND METHODS: Data were collected on allogeneic donations at five US blood centers during 1991 through 2000. Donation characteristics, prevalence, and incidence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) were compared between transfused and nontransfused donors. Unreported deferrable risk (UDR) and reasons to donate were evaluated with data from a mail survey. RESULTS: Transfusion history was reported by 4.2 percent of donors. Prevalence and incidence of HIV and HBV were comparable between transfused and nontransfused donors. Although HCV incidence was similar in both groups, HCV prevalence was nearly three times higher in transfused than in nontransfused first-time donors. UDR and reasons to donate were similar in the two groups, except transfused donors were less likely to donate for screening test results (odds ratio, 0.5; 95% confidence interval, 0.3-0.8). CONCLUSION: Transfused and nontransfused donors had similar viral incidence and comparable UDR, suggesting that indefinite deferral of transfused donors would unlikely improve blood safety. Until more is known about the prevalence and transfusion transmissibility of emerging agents, indefinite deferral of previously transfused donors in the US does not appear warranted.

Adult↗
PubMed2001

Hepatitis G virus biology, epidemiology, and clinical manifestations: Implications for blood safety.

Hepatitis G virus (HGV), also called GBV-C, is a single positive-standard RNA virus belonging to the Flaviviridae family. In 50% to 75% of infections, HGV is cleared with plasma RNA disappearing as anti-E2 becomes detectable; in other cases, HGV infection becomes chronic. The prevalence of HGV RNA in blood donors ranges from 1% to 4%, and the rate of anti-E2, indicating resolved infection, ranges from 3% to 14%. HGV is transmitted by transfusion of blood components and has been transmitted by nonvirally inactivated factor VIII concentrate. Despite extensive study, HGV has not been identified as a causative agent of any type of liver disease or any other known clinical condition. Molecular biology data show a lack of hepatotropism; preliminary data indicate that the site of HGV replication may be in mononuclear cells in bone marrow or spleen but not in peripheral blood or lymph nodes. The combined clinical and laboratory data strongly support the contention that HGV is not a hepatotropic virus and that this virus was inappropriately named hepatitis G. Because the data do not indicate any pathologic effects of HGV, it is not appropriate to screen the blood supply for HGV RNA.

Blood Transfusion↗
PubMed1999

Oversight and monitoring of blood safety in the United States.

The US blood safety vigilance system is composed of a network of interwoven programs, now organized under a formal structure, with the Assistant Secretary of Health and DHHS Blood Safety Committee bearing overall responsibility. It takes advantage of the breadth of expertise and close collaborative relationship of transfusion medicine and infectious disease scientists within and outside of the government. Core elements include an array of ongoing surveillance programs for monitoring established as well as new and emerging infectious agents that may pose a risk to blood safety, and the existence of historical and contemporary repositories of donor and recipient specimens that enable rapid investigation of putative new risks. This report summarizes the historical events that shaped the US blood safety oversight system, reviews the current organization and decision-making processes related to blood safety issues, and highlights key surveillance systems and research programs which monitor the US and global blood supplies for known and potential emerging risks.

Blood Banks↗
PubMed1999

Diagnoses of patients treated with ECT: a comparison of evidence-based standards with reported use.

OBJECTIVE: This study assessed the extent to which patients treated with electroconvulsive therapy (ECT) had diagnoses for which ECT is an efficacious treatment according to evidence-based standards. METHODS: ECT use among all beneficiaries of a large New England insurance company in 1994 and 1995 was examined using a retrospective cohort design. Associations between provider characteristics and ECT use for diagnoses outside the standards were determined using logistic regression analysis. RESULTS: A total of 996 individuals among approximately 1.2 million beneficiaries were treated with ECT. They received a total of 1,532 ECT courses. For 86.5 percent of the courses, the diagnosis was within evidence-based indications; for 13.5 percent, the diagnosis was outside the indications. In more than half of the 13.5 percent of cases, conditions were depressive disorders for which no studies have been conducted or disorders that likely had associated depressive symptoms. Patients receiving ECT for diagnoses outside evidence-based indications were more likely to have been treated by psychiatrists who graduated from medical school between 1940 and 1960 and between 1961 and 1980 than by those who graduated between 1981 and 1990. These patients were also less likely to have been treated by psychiatrists who received their medical education outside the U.S. CONCLUSIONS: Diagnoses of patients treated with ECT were mostly within evidence-based indications. The results provide reassurance to those concerned that ECT may be used indiscriminately. If confirmed by further research, the finding that psychiatrists trained in earlier eras were more likely to use ECT for diagnoses outside evidence-based indications may offer an opportunity for targeted quality improvement.

Cohort Studies↗
PubMed1996

Male-to-female transmission of human T-cell lymphotropic virus types I and II: association with viral load. The Retrovirus Epidemiology Donor Study Group.

SUMMARY: Risk factors for male-to-female sexual transmission of human T-lymphotropic virus types I and II (HTLV-I/II) were investigated among HTLV-seropositive volunteer blood donors and their long-term (> or = 6 month) sex partners. Direction of transmission in concordantly seropositive pairs was assessed by analyzing risk factors for HTLV infection. Donors and their partners were also questioned regarding sexual behaviors during their relationships; HTLV antibody titers and viral load were determined for specimens from male partners. Among 31 couples in whom HTLV-infected men likely transmitted infection to their partners (11 HTLV-I and 20 HTLV-II) and 25 male-positive, female-negative couples (8 HTLV-I and 17 HTLV-II), HTLV transmitter men had been in their relationships longer (mean 225 months vs. 122 months) and had higher viral loads (geometric mean 257,549 vs. 2,945 copies/300,000 cells for HTLV-I; 5,541 vs. 118 copies/300,000 cells for HTLV-II) than non-transmitters (P = 0.018 and P = 0.001 for duration of relationship and viral load, respectively, logistic regression analysis). Transmitter men also tended to have higher antibody titers against various env and whole virus proteins than non-transmitters. The identification of high viral load and duration of relationship as risk factors provides a biologically plausible framework in which to assess risk of sexual transmission of the HTLVs.

Adult↗
PubMed1996

[Tropisetron for the prevention of nausea and vomiting during chemotherapy: multicenter clinical study].

The antiemetic effect of tropisetron was studied in 97 cancer patients (67 men, 30 women) receiving cisplatin in doses of 75 mg/m2 or higher. On 279 chemotherapy cycles studied (max 6 per patient) 5 mg of tropisetron was administered once a day i.v on day 1 and p.o. on days 2 to 6. Efficacy preventing vomiting and nausea was measured in 24 hour period as: complete control O episodes, major control 1 to 2 episodes, minor control 3 to 4 episodes and no control 5 or more episodes. Satisfactory vomiting control (complete and major) was 69%, 63%, 82%, 88%, 96% and 96% in days 1 to 6 of cycle 1. Satisfactory nausea control (complete and major) for the same days was 70%, 66%, 72%, 85%, 92% and 97%. Similar data was obtained for the subsequent cycles. Complete vomiting control was obtained in 47%, 35%, 56%, 72%, 81% and 84% and for nausea in 42%, 39%, 48%, 64%, 81% and 87%. 19 patients presented adverse effects (19.6%). Only 2 headache episodes had a definite relation with the antiemetic drug. 12 patients discontinued the medication; 6 due to drug inefficacy, 2 to illness unrelated to the drug, 1 to lack of collaboration, and 3 due to other reasons. We conclude that tropisetron allows satisfactory control of acute and delayed vomiting in a high percentage of patients treated with high doses of cisplatin. The drug does not have significant secondary effects. Tropisetron administration in only one daily dose implies an evident advantage and a treatment cost reduction.

Adolescent↗
PubMed1995

The cost effectiveness of preoperative autologous blood donations.

BACKGROUND: Since the recognition that human immunodeficiency virus is transmissible by blood transfusion there has been increasing public and professional support for autologous blood donations before elective surgery. Autologous blood donation is, however, a more expensive process than the donation of allogeneic blood by community volunteers. Furthermore, there have been recent improvements in the safety of the volunteer blood supply. METHODS: We used a decision-analysis model to assess the cost effectiveness of donating autologous blood for four surgical procedures. Cost data were collected from the observation of transfusion practice at the University of California, Los Angeles, in 1992. Estimates of the risks of transfusion-associated diseases and the costs of treating them came from the medical literature. Cost effectiveness was expressed in dollars per quality-adjusted year of life saved. We performed sensitivity analyses of the variables in our model and examined the effect of strategies suggested to reduce costs. RESULTS: Substituting autologous for allogeneic blood resulted in little expected health benefit (0.0002 to 0.00044 quality-adjusted year of life saved) at considerable additional cost ($68 to $4,783 per unit of blood). The additional cost of autologous blood was primarily a function of the discarding of units that were donated but not transfused and of a more labor-intensive donation process. The cost-effectiveness ratios ranged from $235,000 to over $23 million per quality-adjusted year of life saved. CONCLUSIONS: Given the improved safety of allogeneic transfusions today, the increased protection afforded by donating autologous blood is limited and may not justify the increased cost.

Blood Transfusion↗
PubMed1994

Duration of time from onset of human immunodeficiency virus type 1 infectiousness to development of detectable antibody. The HIV Seroconversion Study Group.

BACKGROUND: For persons newly infected with the human immunodeficiency virus type 1 (HIV-1), the time from the onset of infectivity to the development of detectable HIV-1 antibody is unknown. Persons who donate blood during this period account for nearly all instances of HIV-1 transmission from HIV-1 antibody-screened blood transfusions. STUDY DESIGN AND METHODS: To estimate the window period from infectivity to HIV-1 antibody positivity, 701 HIV-1-seropositive blood donors who made a previous seronegative donation at 40 United States blood centers were studied. The HIV-1 antibody status was determined for at least one recipient of blood from the seronegative donation preceding the seropositive donation made by 182 of the 701 donors. RESULTS: There were 39 seropositive recipients of blood from these 182 donors. Three donors were excluded from further analysis because the seropositive recipients of their blood had other HIV-1 risk factors or had HIV-1 infection before transfusion. The final study population comprised the remaining 179 donors, of whom 36 (20%) transmitted HIV-1 infection to recipients. When the interval between the seropositive donation and the preceding seronegative donation was less than 180 days, 46 percent of the donors transmitted HIV-1. In contrast, when that interval exceeded 540 days, only 2 percent transmitted HIV-1. A mathematical model was developed to explain the relationship between the probability that the previous seronegative donation occurred during the donor's window period of infectiousness, and hence transmitted HIV-1, as a function of both the window period and the duration between the seropositive and previous seronegative donations. This model indicated that the transmission data were most consistent with an average window period of 45 days. Assuming a log-normal window period distribution, it was estimated with 95 percent certainty that at least 90 percent of persons had a window period of less than 141 days. CONCLUSION: The window period averages 45 days, with few, if any, donors remaining infectious and seronegative for longer than 6 months.

Adolescent↗
PubMed1994

The pharmacology of sevoflurane in infants and children.

BACKGROUND: Sevoflurane is a new volatile anesthetic with physical properties that should make it suitable for anesthesia (MAC of sevoflurane on oxygen alone and in 60% nitrous oxide, (MAC) of sevoflurane in oxygen alone and in 60% nitrous oxide, the hemodynamic, induction and emergence responses to sevoflurane and the metabolism to inorganic fluoride were studied in 90 ASA physical status 1 or 2 neonates, infants, and children. METHODS: MAC of sevoflurane in oxygen was determined in six groups of subjects stratified according to age: full-term neonates, infants 1-6 and > 6-12 months and children > 1-3, > 3-5 and > 5-12 yr. MAC in 60% nitrous oxide was determined in a separate group of children 1-3 yr of age. After an inhalational induction, the trachea was intubated (except for neonates in whom an awake intubation was performed). MAC for each age group was determined using the Up-and-Down technique of Dixon. RESULTS: MAC of sevoflurane in neonates, 3.3 +/- 0.2% and in infants 1-6 months of age, 3.2 +/- 0.1%, were similar; MAC in older infants 6-12 months and children 1-12 yr was constant at approximately 2.5%; MAC of sevoflurane in 60% nitrous oxide in children 1-3 yr of age was 2.0 +/- 0.2%. Systolic arterial pressure decreased significantly at 1 MAC before skin incision compared with awake values in all subjects except children 1-3 yr with 60% nitrous oxide and children 5-12 yr in oxygen, and then returned toward awake values after skin incision. Heart rate was unchanged at approximately 1 MAC sevoflurane before incision compared with awake values in all subjects except children > 3-5 and > 5-12 yr in whom heart rate increased before incision. Induction of anesthesia, particularly with respect to airway irritability, and emergence from sevoflurane anesthesia were not remarkable. The plasma concentration of inorganic fluoride reached maximum values (8.8-16.7 microM) 30 min after discontinuation of anesthesia. CONCLUSIONS: We conclude that sevoflurane appears to be a suitable anesthetic agent for use in neonates, infants and children undergoing < or = 1 h of anesthesia.

Aging↗