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Biomedical subjects

K S Miller

Publications and source records attributed to K S Miller.

At least 19 recordsLinked to original sources
PubMed1999

Cell surface sialic acid and the regulation of immune cell interactions: the neuraminidase effect reconsidered.

It has been known for over a decade that sialidase (neuraminidase) treatment could substantially enhance the capacity of resting B cells to stimulate the proliferation of allogeneic and antigen specific, syngeneic T cells. Thus, cell-surface sialic acid was implicated as a potential modulator of immune cell interaction. However, little progress has been made in either identifying explicit roles for sialic acid in this system or in hypothesizing mechanisms to explain the "neuraminidase effect." Here we show for the first time that cell surface sialic acid on medium incubated B cells blocks access to costimulatory molecules on the B cell surface, and that this is the most likely explanation for the neuraminidase effect. Further, we show that it is likely to be upregulation of ICAM-1 and its subsequent engagement of LFA-1 rather than loss of cell surface sialic acid that in part regulates access to CD86 and other costimulatory molecules. However, we cannot exclude a role for CD86-bound sialic acid on the B cell in modulating binding to T cell CD28. Because sialidase treatment of resting B cells but not resting T cells enables T cell activation, we suggest that sialidase treatment may still be an analogue for an authentic step in B cell activation, and show that for highly activated B cells (activated with polyclonal anti-IgM plus INF-gamma) there is specific loss 2, 6-linked sialic acid. Potential roles for sialic acid in modulating B cell/T cell collaboration are discussed.

Animals↗
PubMed1999

Sexually transmitted diseases, unintended pregnancy, and adolescent health promotion.

Adolescence is a critical period in the development of sexual behaviors that may lead to acquiring sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV), and to unintended pregnancy. Understanding adolescent sexual behavior is essential for understanding adolescents' risk of pregnancy and STD/HIV infection and for planning and evaluating health promotion activities. This chapter reviews the sexual behaviors and psychosocial factors associated with STDs and unintended pregnancy among adolescents as well as school-, community-, and clinic-based interventions designed to reduce risk behaviors and promote adolescent sexual health.

Adolescent↗
PubMed1998

Patterns of condom use among adolescents: the impact of mother-adolescent communication.

OBJECTIVES: The association between the timing of discussions about condoms between mother and adolescent and adolescents' condom use during their first and subsequent sexual encounters was examined. METHODS: Sexually active adolescents reported whether and when they discussed condoms with their mother and answered questions about their own condom use. RESULTS: Mother-adolescent discussions about condoms that occurred prior to sexual debut were strongly associated with greater condom use during first intercourse and most recent intercourse, along with greater lifetime regular condom use. CONCLUSIONS: Discussions about condoms prior to sexual debut are important in promoting condom use among adolescents.

Adolescent↗
PubMed1997

Reports of severe physical punishment and exposure to animal cruelty by inmates convicted of felonies and by university students.

A self-report questionnaire designed to assess abusive childhood environments and exposure to animal cruelty was administered to 314 inmates in a prisoner classification center. Although high rates of physical punishment characterized the entire sample, persons charged with violent, but nonhomicidal crimes reported more severely punitive childhood histories than those charged with homicidal crimes, sex offenses, and nonviolent offenses. Some exposure to animal cruelty was widespread in the sample, but there was no association between experiencing animal cruelty and the type of crime committed. Moreover, there were only modest associations between animal cruelty experiences and the aversive childhood histories of the subjects, as well as the subjects' reported use of physical and sexual coercion in dating and intimate relationships. To determine whether the high base rate of exposure to animal cruelty was unique to the incarcerated sample, a follow-up study was completed with university undergraduates. Widespread exposure to some animal cruelty was reported by undergraduates; there were modest associations between reporting animal cruelty and reporting punitive and acrimonious childhood histories. In general, the findings were consistent with the hypothesis that there is an association between punitive childhood histories and antisocial behavior but not consistent with the hypothesis that exposure to animal cruelty is importantly related to antisocial behavior or child maltreatment.

Adolescent↗
PubMed1997

Adolescent heterosexual experience: a new typology.

PURPOSE: The purpose of this paper is to define a typology that encompasses the full range of adolescent heterosexual behavior; to compare the usefulness of the new typology with that of the traditional dichotomy of "sexually active"/"sexually inactive" for understanding sexual behavior among adolescents; and to determine the implications of the new typology for the design and implementation of HIV prevention programs targeting adolescents. METHODS: Detailed face-to-face interviews were conducted with a cross-sectional sample of 907 mothers and their adolescents, ages 14-17 years, recruited from public high schools in Alabama, New York, and Puerto Rico. Information from the adolescent survey on precoital sexual behaviors and STD/HIV sexual risk and risk reduction behaviors was examined. A typology of adolescent heterosexual experiences was constructed using four behavioral dimensions. RESULTS: Ninety-nine percent (n = 894) of the sample was classified into one of the five patterns of sexual experience: Delayers, Anticipators, One-timers, Steadies, and Multiples. Among the participants who were not sexually active, precoital behaviors differed significantly between the 22% who anticipated initiating sexual intercourse in the next year (Anticipators) and those who did not (Delayers). Among those traditionally classified as "sexually active", One-timers and Steadies were significantly older when they first had penile-vaginal intercourse than those who had multiple partners. One-timers were more likely to use condoms than Steadies or Multiples, and only Multiples reported previous STDs. CONCLUSION: A typology that defines a range of adolescent heterosexual experiences was developed, and it was possible to classify 99% of our sample. The traditional dichotomy between "sexually active" vs. "not active" hides important behavioral intentions and sexual practices. These differences must be taken into account in the development and implementation of HIV prevention programs that target adolescents.

Adolescent↗
PubMed1997

Role of parenting in adolescent deviant behavior: replication across and within two ethnic groups.

The role of 2 parenting variables, monitoring and communication, in adolescent deviant behavior was examined within 4 samples; Black Americans living in Montgomery, Alabama, and the Bronx, New York, and Hispanics living in the Bronx, New York, and San Juan, Puerto Rico. The participants comprised 907 14- to 16-year-old adolescents and their mothers recruited through high schools in 3 communities. The results indicated that higher levels of parental monitoring, but not parent--adolescent communication, predicted lower levels of adolescent deviance in each of the samples. The replication of these findings in samples that vary by ethnicity and location provides strong support for the generalizability of the association between parental monitoring and low levels of adolescent deviant behavior.

Adolescent↗
PubMed1996

Glycosylation of native MHC class Ia molecules is required for recognition by allogeneic cytotoxic T lymphocytes.

The question whether or not target cell N-linked carbohydrate participates in cytotoxic T lymphocyte (CTL) mediated cytolysis has been in contention for well over a decade. Much of the evidence supporting a role for N-linked carbohydrate stems from the treatment of target cells with the glycosylation inhibitor tunicamycin (TM). In this report, we show that treatment of targets with TM, but not other inhibitors of complex carbohydrate formation (swainsonine, 1-deoxynojirimycin, and 1-deoxymannojirimycin), abrogates the lytic response. We conclude that N-linked complex carbohydrates are not absolutely required for the maturation or function of any target cell glycoconjugate directly involved in the lytic process. However, we show that TM treatment of target cells leads to the loss of an MHC class Ia epitope known to be required for T cell triggering. Further, we show that only target cells expressing class Ia molecules with functional glycosylation sequons are subject to the TM effect. From these results we conclude that while N-linked glycosylation of native MHC class Ia molecules is required for antigen presentation, the exact structural motif of the glycan is not important.

1-Deoxynojirimycin↗
PubMed1996

Prevalence of abnormal Pap smears in rural family practice.

The purpose of this study was to examine the prevalence of abnormal Pap smears in rural family practice, to compare this to the published literature, and to determine if the prevalence of abnormalities is higher in the younger age group (<=35 years of age). A retrospective chart audit was performed on all Pap smears from four rural family practice sites during a 12-month period. Data collected were Pap smear result, patient's age, and interval since previous Pap smear. Statistical analysis was used to determine if the prevalence of abnormal Pap smears was consistent among the practices as well as similar to the three larger published studies. Also, chi-square analysis was used to compare the prevalence of abnormal Pap smears in the younger (<=35 years of age) versus the older (>35 years of age) age groups. There were 2,891 Pap smears reviewed, with 782 (27%) recorded as abnormal. The prevalence of cervical intraepithelial neoplasia (CIN) (76 or 2.6%) was compared to the published literature and was found to be statistically significantly higher (chi square=772.194, P=0.000). The prevalence of abnormal Pap smears was higher in the younger than age 35 group when compared to the older than age 35 age group (chi square=20.953, P=0.000). Pap smear interval and age varied between the four practice sites, but the prevalence of CIN was not statistically different (chi square=3.154, P=0.368). The results of this study suggest that rural family physicians may encounter abnormal Pap smears at rates similar to those reported in the literature. This study also suggests that the prevalence of abnormal Pap smears may be higher in the younger groups in this population.

Adult↗
PubMed1996

Quantifying cell mono-layer cultures by video imaging.

A method is described in which the relative number of adherent cells in multi-well tissue-culture plates is assayed by staining the cells with Giemsa and capturing the image of the stained cells with a video camera and charged-coupled device. The resultant image is quantified using the associated video imaging software. The method is shown to be sensitive and reproducible and should be useful for studies where quantifying relative cell numbers and/or proliferation in vitro is required.

Animals↗
PubMed1996

Behavioral risks for HIV infection associated with HIV-testing decisions.

Adolescent and adult women were offered HIV testing as part of a clinic-based research program on HIV/AIDS in New York City. Sixty-four percent consented to testing and 87% of those tested returned to receive their results. This paper uses two-stage regression methods to identify sexual behavioral risk factors for HIV infection associated with the decision to accept the HIV test and subsequently to return for the results. Of the risk factors examined, having more than a single sex partner and never using a condom in the last year were strong predictors of taking the test; three or more sex partners had the strongest effects on the decision to return for the HIV test results. We conclude that voluntary HIV testing in this group can identify women with behavioral risks of HIV infection. Thus, voluntary HIV testing may be effective in targeting persons at high risk because behavioral risks are associated with the decision to take the HIV test.

AIDS Serodiagnosis↗
PubMed1995

Penile intracavernous hematoma: diagnosis and surgical considerations.

Soft tissue lesions of the penile corporeal bodies are rare and usually represent benign or malignant tumors, or Peyronie's disease. We report a unique case of a deep seated penile mass that at exploration proved to be an encapsulated hematoma of the inter-corporeal septum. Preoperative diagnosis of lesions of the corporeal bodies is facilitated by high resolution Doppler ultrasonography. Surgical exploration to exclude malignancy must be done unless the clinical and/or radiographic findings are unequivocally benign (Peyronie's plaque, simple cyst and so forth). Surgical exploration must be done according to the penile neurovascular anatomy to preserve potency and glanular sensation.

Hematoma↗
PubMed1995

Radiographic assessment of renal trauma: our 15-year experience.

PURPOSE: We sought to evaluate the continuing validity of our criteria for radiographic imaging of renal injuries, that is penetrating flank or abdominal trauma, blunt trauma with gross hematuria or microscopic hematuria and shock, deceleration or major associated abdominal injury and pediatric renal trauma. MATERIALS AND METHODS: We reviewed the records of 2,254 patients who presented to our institution with suspected renal trauma between 1977 and 1992. RESULTS: Of the 1,588 blunt trauma patients with microscopic hematuria and no shock 3 had significant injury but these cases were discovered during imaging or exploratory laparotomy for associated injuries. Followup in 515 of 1,004 patients (51%) who did not undergo initial imaging revealed no significant complications. CONCLUSIONS: Adults with blunt renal trauma, microscopic hematuria and no shock or major associated intra-abdominal injuries can safely be spared radiographic imaging.

Follow-Up Studies↗
PubMed1994

Phenotype and TCR gamma delta variable gene repertoire of intestinal intraepithelial lymphocytes in wild mice (Mus musculus domesticus): abundance of V gamma 1 transcripts and extensive delta gene diversity.

In order to study murine intestinal intraepithelial lymphocytes (IEL) independent of factors imparted by conditions of laboratory housing and breeding, and to provide a basis for comparison of IEL studies between inbred and outbred mouse populations, IEL from the domestic house mouse, Mus musculus domesticus, were analyzed by flow cytometric analyses using mAbs to murine lymphocyte markers, and by polymerase chain reaction to study the TCR gamma and delta V gene repertoires. The majority of IEL in wild mice were CD3+, CD8+CD4- T cells. CD4+CD8- also were present in IEL isolates from wild mice, although at low numbers. Among IEL, but not T cells from the spleen or lymph nodes, there was a notable lack of Thy-1 expression, a preponderance of CD8 alpha alpha + T cells, and a relatively high ratio (3:1) of TCR gamma delta + T cells over TCR alpha beta + T cells, suggesting that some IEL in wild mice may develop via an extrathymic pathway similar to that described for laboratory mice. Analyses of the IEL gamma and delta variable genes revealed rearrangements of three of six V region gamma genes (V gamma 1, V gamma 2, and V gamma 5), with an abundance of V gamma 1 transcripts as determined by Northern blot analyses. For the delta gene, rearrangement of five of seven V region elements had occurred (V delta 2, V delta 3, V delta 4, V delta 5, and V delta 6).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗