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Biomedical subjects

G Schiff

Publications and source records attributed to G Schiff.

At least 19 recordsLinked to original sources
PubMed2003

The progestative effect of the levonorgestrel-releasing intrauterine system--when does it manifest?

The objective of the study was to evaluate, clinically and sonographically, the time required for the progestative effect of the levonorgestrel-releasing intrauterine system (IUS, Mirena) to be manifested. Doppler flow of the cervical branch and spiral artery of the uterine artery, as well as the endometrial width (up to day 10 of the cycle), were evaluated in 36 women carrying levonorgestrel-releasing IUS 1-2 months after insertion of the device compared to 4-6 months after insertion. The rate of intermenstrual bleeding was reduced from 44% during the first 2 months, to only 8% of women after 4-6 months of use. Complete cessation of menstrual bleeding occurred in 5% after 2 months and in 66% after 4-6 months following insertion. While there was no change in the Doppler flow in the cervical branch of the uterine artery between both groups, there was a significant reduction in the subendometrial flow in the spiral artery. This observation was reinforced by the demonstration of significant reduction in endometrial thickness in the following 4 months of use. The present study has demonstrated that the local progestative effect of the levonorgestrel-releasing IUS on the endometrium is already manifested within a period of 3 months and over after insertion.

Adult↗
PubMed2000

Oral oseltamivir in human experimental influenza B infection.

Oseltamivir is the prodrug of Ro64-0802 (GS4071), a potent and selective inhibitor of influenza A and B virus neuraminidases. Three randomized, double-blind, placebo-controlled, parallel-group studies evaluated oral oseltamivir for early treatment (75 or 150 mg twice daily for 5 days) or prevention (75 mg once or twice daily for 7 days) of experimental influenza B virus infection in healthy susceptible adults. Treatment study A (n=60) demonstrated similar trends to treatment study B (n=117), in which 75 mg doses of oseltamivir introduced 24 h after inoculation reduced median area under curve (AUC) virus titre (oseltamivir, 22.7; placebo, 131.1 log10 TCID50 x h/ml; P=0.002) and duration of viral shedding (oseltamivir, 23.9 h; placebo, 95.8 h; P=0.0005). In prevention study C (n=58), oseltamivir did not reduce infection rates (85 versus 84%) but significantly reduced median AUC virus titre (10.0 versus 66.9 log10 TCID50 x h/ml; P=0.03) and duration of viral shedding (36 versus 84 h; P=0.03) compared with placebo. Oseltamivir was well tolerated. No emergence of drug-resistant variants was detected by testing last-day isolates (n=112) in neuraminidase inhibition assays. These results indicate that oseltamivir has significant antiviral activity in experimental human influenza B virus infection when used for prophylaxis or early treatment.

Acetamides↗
PubMed1999

Randomized, double-blind, placebo-controlled, multicentered trial of the efficacy of a single dose of live oral cholera vaccine CVD 103-HgR in preventing cholera following challenge with Vibrio cholerae O1 El tor inaba three months after vaccination.

CVD 103-HgR is a live oral cholera vaccine strain constructed by deleting 94% of the gene for the enzymatically active A subunit of cholera toxin from classical Inaba Vibrio cholerae O1 569B; the strain also contains a mercury resistance gene as an identifying marker. This vaccine was well tolerated and immunogenic in double-blind, controlled studies and was protective in open-label studies of volunteers challenged with V. cholerae O1. A randomized, double-blind, placebo-controlled, multicenter study of vaccine efficacy was designed to test longer-term protection of CVD 103-HgR against moderate and severe El Tor cholera in U.S. volunteers. A total of 85 volunteers (50 at the University of Maryland and 35 at Children's Hospital Medical Center/University of Cincinnati) were recruited for vaccination and challenge with wild-type V. cholerae El Tor Inaba. Volunteers were randomized in a double-blind manner to receive, with buffer, a single oral dose of either CVD 103-HgR (2 x 10(8) to 8 x 10(8) CFU) or placebo (killed E. coli K-12). About 3 months after immunization, 51 of these volunteers were orally challenged with 10(5) CFU of virulent V. cholerae O1 El Tor Inaba strain N16961, prepared from a standardized frozen inoculum. Ninety-one percent of the vaccinees had a >/=4-fold rise in serum vibriocidal antibodies after vaccination. After challenge, 9 (39%) of the 23 placebo recipients and 1 (4%) of the 28 vaccinees had moderate or severe diarrhea (>/=3-liter diarrheal stool) (P < 0.01; protective efficacy, 91%). A total of 21 (91%) of 23 placebo recipients and 5 (18%) of 28 vaccinees had any diarrhea (P < 0.001; protective efficacy, 80%). Peak stool V. cholerae excretion among placebo recipients was 1.1 x 10(7) CFU/g and among vaccinees was 4.9 x 10(2) CFU/g (P < 0.001). This vaccine could therefore be a safe and effective tool to prevent cholera in travelers.

Administration, Oral↗
PubMed1998

Primary care for the medically underserved: challenges and opportunities.

The medically underserved present unique challenges to primary care practitioners. Sociocultural and financial barriers of the underserved impede access to necessary care; the prevalence and severity of diseases in the underserved population vary from those of the general population; the institution of preventive-care measures can be especially problematic; and the doctor-patient relationship is uncommonly complex. This article reviews current thinking about the causes of unequal health, the effects of unequal health care, and the special opportunities for disease prevention among the socioeconomically disadvantaged people in the US. Sensitivity to these and other issues can enhance primary care practitioners' efforts to improve care of the underserved now, pending future political consensus about universal health insurance.

Delivery of Health Care↗
PubMed1998

Validation of a volunteer model of cholera with frozen bacteria as the challenge.

To evaluate a standardized inoculum of Vibrio cholerae for volunteer challenge studies, 40 healthy adult volunteers were challenged at three different institutions with a standard inoculum prepared directly from vials of frozen, virulent, El Tor Inaba V. cholerae N16961, with no further incubation. Groups of 5 volunteers, with each group including 2 volunteers with blood group O, were given a dose of 10(5) CFU, and 34 of the 40 volunteers developed diarrhea (mean incubation time, 28 h). Transient fevers occurred in 15 (37.5%) of the volunteers. V. cholerae was excreted by 36 of 40 volunteers. Five additional volunteers received 10(4) CFU, and four developed diarrhea but with a lower average purging rate than required for the model. Of the 40 volunteers, 37 developed rises in their vibriocidal and antitoxin titers similar to those in previous groups challenged with freshly harvested bacteria. We conclude that challenge with frozen bacteria results in a reproducible illness similar to that induced by freshly harvested bacteria. Use of this model should minimize differences in attack rates or severity when groups are challenged at different times and in different institutions.

Adolescent↗
PubMed1998

Voting with their feet: public hospitals, health reform, and patient choices.

OBJECTIVES: This study identified public hospital patients' preferences under managed care and health reform. METHODS: A cross-sectional survey of 348 ambulatory public hospital patients was conducted. RESULTS: Patients reported a high degree of loyalty to the public hospital given several hypothetical reform scenarios. Those patients who stated they would remain at the hospital increased (from 74.2% to 85.5%) when care elsewhere required copayment for medications and physician visits. CONCLUSIONS: Patients at one public hospital reported a high likelihood of remaining in the public system, and this likelihood increased when copayment for services was required elsewhere.

Adult↗
PubMed1997

Continuous quality improvement at the crossroads: contradictions and challenges.

Continuous quality improvement stands at a crossroads. One road is dominated by the frenzied competition in the current health care marketplace. Another road is traveled both by a desire to compete against disease and by vulnerable employees, many of whom are represented by a weakened union movement. This article reviews this history and lessons and its relationship to CQI. Employee involvement, not just from a psychologic, but also a decision-making and even ownership perspective is necessary for CQI to succeed in the long term. Only with this type of involvement in hand can the trust between employee and employer required for genuine CQI be created.

Communism↗
PubMed1992

Seroepidemiologic evaluation of antibodies to rotavirus as correlates of the risk of clinically significant rotavirus diarrhea in rural Bangladesh.

A case-control study was conducted among children and adult women in rural Bangladesh to evaluate whether serologic immunity to rotavirus was associated with a lower risk of rotavirus diarrhea of sufficient severity to cause patients to seek medical care. Acute-phase sera from 219 cases of rotavirus diarrhea, detected among patients treated in three diarrheal treatment centers, were compared with sera from 477 contemporaneously selected community controls. Overall, serum IgG antirotavirus antibody titers were nearly one-fourth as high in cases as in controls (107 vs. 417 units/ml; P less than .001). Among persons aged greater than or equal to 8 months, in whom titers of maternal antirotavirus antibodies should have been negligible, even the lowest range of detectable titers (100-200 units/ml) was associated with a substantial (75%, P less than .05) reduction of the risk of rotavirus diarrhea. We conclude that titers of serum IgG antirotavirus antibodies induced by earlier infection were inversely related to the risk of clinically significant rotavirus diarrhea.

Adult↗
PubMed1990

Drug formularies: myths-in-formation.

Drug formularies are pivotal tools for delineating and directing prescribing to the "drugs of choice." Full realization of their potential has been hampered by insufficient comparative data on drug efficacy/safety and local resources for formulary development. However, misconceptions concerning fundamental formulary concepts pose an even more formidable obstacle. This article identifies statements illustrating formulary misconception a) made by physicians attending Pharmacy and Therapeutics Committee meetings during a three-year period and b) appearing in published sources. The paper highlights basic objectives and operational requirements of an effective formulary, and contrasts this definition with 20 myths and misinformation culled from these two sources. Not only does such misinformation impair formulary development, many critics are so preoccupied with alleged shortcomings that progress in minimizing the real limitations of formularies has been impeded.

Attitude of Health Personnel↗
PubMed1990

In vitro virucidal effectiveness of a 0.12%-chlorhexidine gluconate mouthrinse.

The purpose of this work was to assess the in vitro antiviral effectiveness of a mouthrinse (Peridex) containing 0.12% chlorhexidine gluconate (CH) on several viruses that are associated with the oral cavity. These included herpes simplex virus (HSV), cytomegalovirus (CMV), influenza A, parainfluenza, polio, and hepatitis B (HBV). Virucidal assays in tissue cultures were performed on all viruses except HBV. The virucidal effect on HBV was assessed by inactivation of the DNA polymerase contained within the Dane particle of HBV. The CH mouthrinse had virucidal activity against all of the viruses, except polio, in as little as 30 s. The virucidal activity increased with time. However, there were differences in the responses of these viruses to the challenge of the CH mouthrinse, probably due to subtle differences in the physical/chemical structures of the virus envelopes. Results on DNA polymerase of the HBV virus were similar to those on the other viruses, except polio, suggesting a common mechanism. With respect to this mechanism, it was proposed that CH exerted its antiviral effect on the envelopes of these viruses, and that the absence of an envelope on polio precluded effectiveness against this virus.

Animals↗
PubMed1980

Relating infant temperament to learning disabilities.

The role of infant temperament in the development of learning disabilities was at issue. As infants, boys with severe learning disabilities were found to be (1) lower in activity level, (2) more irregular, (3) less approaching, and (4) more negative in mood than "normal" boys. Discussion centered around conceptualizing learning disabilities as the outcome of a developmental process. Thus patterns of early parent-infant interaction are established, based in part upon the infant's temperament, that may evolve into a learning disability.

Child↗