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Biomedical subjects

C E Stevens

Publications and source records attributed to C E Stevens.

At least 91 records · Page 5Linked to original sources
PubMed1988

Colposcopic manifestations of cervical and vaginal infections.

We analyzed the associations of colposcopic features with cervical and vaginal pathogens and with clinical diagnoses in randomly selected women attending a clinic for sexually transmitted diseases. Logistic regression models were used to adjust for coinfections. Significant associations (P less than 0.01) were found for endocervical mucopus with C. trachomatis, N. gonorrhoeae, and herpes simplex virus (HSV); ulcers/necrotic areas with HSV; "strawberry cervix" with T. vaginalis; increased surface vascularity with HSV; hypertropic cervicitis with C. trachomatis; and immature metaplasia with C. trachomatis and cytomegalovirus. Koilocytosis on cervical cytology was significantly associated with an atypical transformation zone on colposcopy, as well as with satellite lesions. The presence of leukoplakia and ectocervical asperities were also associated with koilocytosis. Awareness of these associations is important for colposcopists to identify patients who need specific microbiologic studies. Although colposcopy is generally used to evaluate patients selected because of abnormal cytology, our study suggests that colposcopic examination could be a useful adjunct to cytology in screening for a variety of cervical and vaginal infections.

Adolescent↗
PubMed1987

Yeast-recombinant hepatitis B vaccine. Efficacy with hepatitis B immune globulin in prevention of perinatal hepatitis B virus transmission.

A yeast-recombinant hepatitis B vaccine was licensed recently by the Food and Drug Administration and is now available. To assess the efficacy of the yeast-recombinant vaccine, we administered the vaccine in combination with hepatitis B immune globulin to high-risk newborns. If infants whose mothers were positive for both hepatitis B surface antigen and the e antigen receive no immunoprophylaxis, 70% to 90% become infected with the virus, and almost all become chronic carriers. Among infants in this study who received hepatitis B immune globulin at birth and three 5-micrograms doses of yeast-recombinant hepatitis B vaccine, only 4.8% became chronic carriers, a better than 90% level of protection and a rate that is comparable with that seen with immune globulin and plasma-derived hepatitis B vaccine. These data suggest that, in this high-risk setting, the yeast-recombinant vaccine is as effective as the plasma-derived vaccine in preventing hepatitis B virus infection and the chronic carrier state.

Carrier State↗
PubMed1986

Human T-cell lymphotropic virus type III infection in a cohort of homosexual men in New York City.

Using blood samples collected since 1978, we investigated the epidemiology of human T-cell lymphotropic virus type III (HTLV-III), the etiologic agent of the acquired immunodeficiency syndrome, in a group of 378 homosexually active men who have resided in New York City since the acquired immunodeficiency syndrome epidemic began. The anti-HTLV-III prevalence was 6.6% in sera from 1978 or 1979, and the subsequent annual incidence of seroconversion among susceptible men ranged between 5.5% and 10.6%. The highest incidences were in recent years, even though these men reported a decrease in their sexual activity during this time. These data demonstrate the continuing risk of HTLV-III infections in the homosexual population studied and emphasize the need for more effective prevention of transmission. The year during which antibody was first present was the only factor identified that was associated with altered cell-mediated immunity in antibody-positive men. Men who became antibody positive in 1981 or earlier currently had significantly lower OKT4/OKT8 ratios than did those who seroconverted more recently. Further follow-up will be necessary to establish the reasons for this association.

Acquired Immunodeficiency Syndrome↗
PubMed1986

New findings in live, attenuated hepatitis A vaccine development.

Strain CR326F of hepatitis A virus, derived from a fecal specimen of Costa Rican patient 033-03, was passed 15 times in fetal rhesus monkey kidney (FRhK6) cell cultures plus eight times in human diploid lung (MRC5) cell cultures to yield variant F and 16 times in MRC5 cell cultures to yield variant F'. Both variants were purified by limit dilution passages. Virulence for marmosets was assessed at six different passage levels, including variants F and F'. There was a gradual loss of virulence with in vitro passage. Variant F retained slight virulence for marmosets; variant F' showed no evidence of virulence. Both variants induced hepatitis A antibody in most marmosets that received them, and the animals were immune to infection when challenged. Variants F and F' were also assessed in chimpanzees. As in marmosets, F retained slight virulence but F' did not. Experimental vaccines made from variants F and F' were then inoculated parenterally into adult human volunteers. A portion of recipients of variant F showed brief, low-order enzyme elevations; none was seen in recipients of F', although their occurrence could not be totally ruled out. As in the animal models, F' appeared more attenuated than F. Most persons developed hepatitis A antibody, indicating the feasibility of developing a live, attenuated hepatitis A vaccine for human beings.

Animals↗
PubMed1986

Etiology of cervical inflammation.

We studied the relationships of selected microbial, clinical, demographic, and behavioral variables to mucopurulent cervicitis in two clinical settings, a sexually transmitted disease clinic and a student health clinic. From each clinic, we studied a group of women referred for suspected mucopurulent cervicitis and a representative sample of other women attending the clinic. After the women were stratified by patient group and summary odds ratios for all groups were obtained, mucopurulent cervicitis was most strongly associated with the isolation of Chlamydia trachomatis; other variables associated with mucopurulent cervicitis included the isolation of Ureaplasma urealyticum, Gardnerella vaginalis, and Trichomonas vaginalis, the presence of serum antibody to C. trachomatis, the clinical diagnosis of bacterial vaginosis, and oral contraceptive use (positive associations) or isolation of yeast (negative association). After adjustment for cervical culture results for C. trachomatis, mucopurulent cervicitis was positively associated with oral contraceptive use (p = 0.02) and isolation of U. urealyticum (p = 0.02) and negatively associated with isolation of yeast (p = 0.03). Among women with a positive cervical culture for C. trachomatis, isolation of U. urealyticum was significantly associated with mucopurulent cervicitis, while among the subgroup of women with a negative cervical culture for C. trachomatis and positive serum antibody to C. trachomatis, oral contraceptive use was strongly associated with mucopurulent cervicitis. These results confirm that in both clinical settings C. trachomatis is the major cause of mucopurulent cervicitis. The roles of U. urealyticum, T. vaginalis, G. vaginalis, bacterial vaginosis, and oral contraceptive use in the etiology of mucopurulent cervicitis deserve further study.

Adult↗
PubMed1986

Comparative physiology of the mammalian colon and suggestions for animal models of human disorders.

The large intestine is absent from the digestive tract of some mammals and shows a considerable degree of gross structural variation among the other species. The cecum serves as the major site for digesta retention and microbial fermentation in lagomorphs, most rodents, and many herbivorous marsupials, but the proximal colon appears to serve this purpose in most other mammals. The VFA end-products of microbial fermentation play an important role in the normal secretory and absorptive processes of the colon. Among those species that have received the most extensive study, the pig appears to have a colon most similar to that of humans in its gross structural and absorptive characteristics.

Animals↗
PubMed1985

Prevalence and manifestations of endometritis among women with cervicitis.

Thirty-five women referred from a clinic treating sexually transmitted diseases, because of suspected cervicitis, were studied for the presence of endometritis by transcervical endometrial biopsies and cervical and endometrial cultures. Fourteen (40%) of the patients had histologic evidence of endometritis. Findings that significantly correlated with endometritis included a history of intermenstrual vaginal bleeding, the presence of Chlamydia trachomatis, Neisseria gonorrhoeae, or Streptococcus agalactiae in the cervix, and the presence of serum antibodies to C. trachomatis or to Mycoplasma hominis.

Antibodies, Bacterial↗
PubMed1985

Cytologic manifestations of cervical and vaginal infections. I. Epithelial and inflammatory cellular changes.

We used multiple logistic regression to analyze microbiological and clinical correlates of inflammatory and epithelial cell changes on Papanicolaou-stained cervical smears in patients from a sexually transmitted disease clinic. Among randomly selected patients, increased numbers of histiocytes and polymorphonuclear leukocytes and the presence of transformed lymphocytes were associated with Chlamydia trachomatis infection, while increased lymphocytes were associated with Trichomonas vaginalis infection; minimal squamous atypia was associated with yeast infection; and moderate squamous atypia and koilocytosis were associated with cervical condylomata visualized by colposcopy. Among patients referred for cervicitis, C trachomatis infection was also associated with reactive or atypical metaplastic cells. Distinct inclusions were seen by Papanicolaou smear in only 22% of C trachomatis infections. In randomly selected patients, however, the presence of transformed lymphocytes or increased histiocytes had a sensitivity of 95%, a specificity of 75%, and a positive predictive value of 50% in relation to isolation of C trachomatis, and could therefore be used for selection of patients for confirmatory testing for C trachomatis infection.

Adult↗
PubMed1985

Cybernetic appropriateness review. Does it change physician hospital utilization patterns?

All hospital care can be characterized as either appropriate (i.e., efficatious and necessary) or inappropriate (i.e., services without benefit or services that could be provided in a less costly setting). A demonstration project combining an appropriateness determination methodology with a cybernetic control system was implemented in a study area that included six hospitals and approximately 400 practicing physicians. Project results to date indicate substantial improvements in the ratio of appropriate to inappropriate care for both hospitals and individual physicians. Evaluation research design problems and areas of future research are also discussed.

Cybernetics↗
PubMed1985

Radioimmunoassay and enzyme-linked immunoassay of antibodies directed against lymphadenopathy-associated virus (LAV) proteins larger than the core protein (P24).

The acquired immunodeficiency syndrome (AIDS) may be transmitted by blood transfusions and by blood products from donors who have been infected with the lymphadenopathy-associated virus (LAV). Such donors may generally be identified on the basis of a positive test for antibodies-against LAV proteins. We have already described an anti-LAV assay based on the use of crude virus-infected tissue culture medium, which avoids elaborate, expensive and potentially hazardous virus purification steps. This test was operationally specific for antibodies to the approximately 24 kD core protein of the virus (P24; Neurath et al. J. Virol. Methods 11, 75, 1985). Molecular exclusion chromatography of crude LAV antigen preparations allows separation of most of P24 from larger proteins of LAV (PL). PL and 125I- or beta-lactamase-labeled anti-LAV were used as reagents for radioimmunoassay (RIA)--or enzyme-linked immunoassay (ELISA)--inhibition tests to detect antibodies directed predominantly against PL (anti-PL). Among 257 individuals belonging to groups at high risk of developing AIDS, 117 (45.5%) were positive for anti-PL and 108 (42%) for anti-P24, respectively. The 2 individuals among 600 random blood donors found to be anti-P24-positive in the preceding study also had anti-PL in their serum. Sera from 500 additional blood donors were screened for anti-PL and 1 of these was positive. The implication of these findings for screening of blood donors is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Radioimmunoassay and enzyme-linked immunoassay of antibodies to the core protein (P24) of human T-lymphotropic virus (HTLV III).

Human T-cell lymphotropic viruses designated HTLV III or LAV are considered to represent the causative agent(s) of the acquired immunodeficiency syndrome (AIDS). Individuals who have been infected with these viruses may generally be identified on the basis of a positive serological test for antibodies against the protein components of these viruses. Purified viruses or viral proteins have been utilized for developing such tests. Since AIDS may be transmitted by blood transfusion and by blood products, screening of donors for antibodies to HTLV III/LAV has become a necessity. Such screening may be facilitated by the application of assays based on the use of crude virus-infected tissue culture media avoiding elaborate, expensive and potentially hazardous virus purification steps. Serum specimens were mixed with an appropriate dilution of an HTLV III-infected tissue culture-derived fraction, obtained by precipitation with polyethylene glycol 6000 and treatment with Tween 80 and tri-n-butylphosphate (to disrupt virus particles), and incubated with polystyrene beads coated with antibodies to HTLV III/LAV (anti-HTLV III). Subsequently, washed beads were incubated with either 125I- or beta-lactamase-labeled anti-HTLV III. The radioactivity or enzymatic activity associated with the beads was proportionate to the quantity of HTLV III antigen originally added to the beads. The presence of anti-HTLV III in serum specimens resulted in decreased antigen binding and thus in decreased radioactivity or diminished beta-lactamase activity associated with the beads. The test was specific for antibodies to the approximately equal to 24 kDa core protein of HTLV III. The prevalence of these antibodies (given in parentheses) in distinct populations was as follows: random blood donors (0.33%); hemophiliacs (36.4%); random homosexual males (25.1%); homosexual males preselected on the basis of positive markers for infection with hepatitis B virus (50%); and those with persistent lymphadenopathy (70%).

Acquired Immunodeficiency Syndrome↗
PubMed1985

Impact of a cybernetic system of feedback to physicians on inappropriate hospital use.

A cybernetic control program aimed at reducing inappropriate days of hospital stay for patients was implemented for all Medicare admissions at hospitals in four counties in Western Maryland. The findings of a study of the program are reported here. The objective of the study was to determine the relationship of the volume of the physician's hospitalized patients on both the existing levels of inappropriate hospital utilization and the physician's response to the cybernetic system. The findings indicated that: (a) existing levels of inappropriate hospital use generally increased with higher patient volume, (b) physicians with a low volume of hospitalized patients were less likely to decrease their inappropriate use of hospitals as a result of feedback than physicians with medium or high volumes of admitted patients, and (c) at all volume levels, the average decrease in inappropriate days was larger than the average increase in inappropriate days.

Cybernetics↗
PubMed1984

Hepatitis B vaccine in patients receiving hemodialysis. Immunogenicity and efficacy.

We evaluated the immunogenicity and efficacy of hepatitis B vaccine (Heptavax-B) in a randomized, double-blind, placebo-controlled trial involving 1311 patients receiving hemodialysis in the United States. After three doses of vaccine (40 micrograms each) had been administered, 63 per cent of the patients were antibody-positive. After correction for possible passive transfer of antibodies by blood transfusion, only 50 per cent of vaccine recipients were considered vaccine responders. The incidence of hepatitis B viral infection during the 25 months of the trial was much lower than had been anticipated and was virtually the same in the vaccine and placebo recipients (6.4 and 5.4 per cent, respectively). Four cases of hepatitis B occurred in patients who had an apparent antibody response to the vaccine, but in each case either antibody had reached low or undetectable levels before hepatitis B surface antigen was detected or the patient had been receiving immunosuppressive therapy. This study did not demonstrate the efficacy of the vaccine in a population of patients receiving dialysis in whom both the rate of antibody response to hepatitis B vaccine and the viral attack rate were low. Other measures to control transmission of hepatitis B virus in dialysis units, including surveillance for hepatitis B surface antigen and isolation of patients who are positive for the antigen, must be continued.

Adult↗
PubMed1984

Mucopurulent cervicitis--the ignored counterpart in women of urethritis in men.

Among 100 randomly selected nonmenstruating women attending a clinic for sexually transmitted diseases, we assessed objective criteria for the clinical diagnosis of mucopurulent cervicitis. Visualization of yellow mucopurulent endocervical secretions on a white swab and the presence of 10 or more polymorphonuclear leukocytes per microscopical field (at a magnification of 1000) in satisfactory gram-stained endocervical smears were independently correlated with cervical Chlamydia trachomatis infection. Neither finding correlated with gonorrhea or genital herpes, although herpes caused characteristic cervical ulcerations. C. trachomatis was isolated from the cervix of 20 of 40 women with mucopurulent cervicitis but of only 2 of 60 without it. The overall prevalence of mucopurulent cervicitis among women attending the clinic (40 per cent) exceeded that of nongonococcal urethritis among men in the same clinic, and the prevalence of C. trachomatis infection was higher in mucopurulent cervicitis than in nongonococcal urethritis, a condition that is conventionally treated with tetracyclines. These findings support recommendations for the treatment of mucopurulent cervicitis and should guide the selective use of confirmatory diagnostic tests for C. trachomatis infection.

Adolescent↗