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Biomedical subjects

A Lentz

Publications and source records attributed to A Lentz.

10 recordsLinked to original sources
PubMed2001

Fleeting foreskins: the misclassification of male circumcision status.

BACKGROUND: Errors in the classification of male circumcision status could bias studies linking infection to lack of circumcision. GOAL: To determine the frequency and factors associated with the reproducibility of reporting circumcision status. STUDY DESIGN: Secondary analysis of data using logistic regression modeling from a multicenter randomized controlled trial was performed. RESULTS: At follow-up assessment, 15.6% of clinician reports on circumcision status disagreed with baseline reports. Disagreement was more common if both clinicians were women than if both were men (odds ratio [OR], 2.8; 95% CI, 1.9-4.1). As compared with whites reported as circumcised (4%, 19/532 visits), the highest disagreement involved uncircumcised Hispanic (OR, 3.3; 95% CI, 1.7-6.3), white (OR, 12.2; 95% CI, 5.8-25.6), or black (OR, 17.1; 95% CI, 10.4-27.9) men. CONCLUSIONS: This is one study among a small number of studies examining the reproducibility of clinician-reported circumcision status by comparing multiple clinical examinations of the same patient. The magnitude of the misclassification discovered could bias results and indicates the need for greater accuracy in reporting circumcision status in future studies.

Adult↗
PubMed2000

Disulfide bond formation between RNA binding domains is used to regulate mRNA binding activity of the chloroplast poly(A)-binding protein.

Binding of the chloroplast poly(A)-binding protein, RB47, to the psbA mRNA is regulated in response to light and is required for translation of this mRNA in chloroplasts. The RNA binding activity of RB47 can be modulated in vitro by oxidation and reduction. Site-directed mutations to individual cysteine residues in each of the four RNA binding domains of RB47 showed that changing single cysteines to serines in domains 2 or 3 reduced, but did not eliminate, the ability of RB47 to be redox-regulated. Simultaneously changing cysteines to serines in both domains 2 and 3 resulted in the production of RB47 protein that was insensitive to redox regulation but retained the ability to bind the psbA mRNA at high affinity. The poly(A)-binding protein from Saccharomyces cerevisiae lacks cysteine residues in RNA binding domains 2 and 3, and this poly(A)-binding protein lacks the ability to be regulated by oxidation or reduction. These data show that disulfide bond formation between RNA binding domains in a poly(A)-binding protein can be used to regulate the ability of this protein to bind mRNA and suggest that redox regulation of RNA binding activity may be used to regulate translation in organisms whose poly(A)-binding proteins contain these critical cysteine residues.

Amino Acid Sequence↗
PubMed1998

Efficacy of risk-reduction counseling to prevent human immunodeficiency virus and sexually transmitted diseases: a randomized controlled trial. Project RESPECT Study Group.

CONTEXT: The efficacy of counseling to prevent infection with the human immunodeficiency virus (HIV) and other sexually transmitted diseases (STDs) has not been definitively shown. OBJECTIVE: To compare the effects of 2 interactive HIV/STD counseling interventions with didactic prevention messages typical of current practice. DESIGN: Multicenter randomized controlled trial (Project RESPECT), with participants assigned to 1 of 3 individual face-to-face interventions. SETTING: Five public STD clinics (Baltimore, Md; Denver, Colo; Long Beach, Calif; Newark, NJ; and San Francisco, Calif) between July 1993 and September 1996. PARTICIPANTS: A total of 5758 heterosexual, HIV-negative patients aged 14 years or older who came for STD examinations. INTERVENTIONS: Arm 1 received enhanced counseling, 4 interactive theory-based sessions. Arm 2 received brief counseling, 2 interactive risk-reduction sessions. Arms 3 and 4 each received 2 brief didactic messages typical of current care. Arms 1, 2, and 3 were actively followed up after enrollment with questionnaires at 3, 6, 9, and 12 months and STD tests at 6 and 12 months. An intent-to-treat analysis was used to compare interventions. MAIN OUTCOME MEASURES: Self-reported condom use and new diagnoses of STDs (gonorrhea, chlamydia, syphilis, HIV) defined by laboratory tests. RESULTS: At the 3- and 6-month follow-up visits, self-reported 100% condom use was higher (P<.05) in both the enhanced counseling and brief counseling arms compared with participants in the didactic messages arm. Through the 6-month interval, 30% fewer participants had new STDs in both the enhanced counseling (7.2%; P= .002) and brief counseling (7.3%; P= .005) arms compared with those in the didactic messages arm (10.4%). Through the 12-month study, 20% fewer participants in each counseling intervention had new STDs compared with those in the didactic messages arm (P = .008). Consistently at each of the 5 study sites, STD incidence was lower in the counseling intervention arms than in the didactic messages intervention arm. Reduction of STD was similar for men and women and greater for adolescents and persons with an STD diagnosed at enrollment. CONCLUSIONS: Short counseling interventions using personalized risk reduction plans can increase condom use and prevent new STDs. Effective counseling can be conducted even in busy public clinics.

Adolescent↗
PubMed1998

What about money? Effect of small monetary incentives on enrollment, retention, and motivation to change behaviour in an HIV/STD prevention counselling intervention. The Project RESPECT Study Group.

OBJECTIVES: We studied the effect of small monetary incentives and non-monetary incentives of similar value on enrollment and participation in clinic based HIV/STD prevention counselling. We examined incident STDs to try to assess whether participants offered money may be less motivated to change risky behaviours than those offered other incentives. METHODS: Patients from five US STD clinics were invited to enroll in a multisession risk reduction counselling intervention and, based on their enrollment date, were offered either $15 for each additional session or non-monetary incentives worth $15. The two incentive groups were compared on participants' enrollment, completion of intervention sessions, and new STDs over the 24 months after enrollment. RESULTS: Of 648 patients offered money, 198 (31%) enrolled compared with 160 (23%) of 696 patients offered other incentives (p = 0.002). Enrollees in the two incentive groups had similar baseline characteristics, including condom use. Of the 198 participants offered money, 109 (55%) completed all sessions compared with 59 (37%) of the participants offered other incentives (p < 0.0001). Comparing those offered money with those offered other incentives STD rates were similar after 6, 12, and 24 months. CONCLUSIONS: Small monetary incentives enhanced enrollment and participation compared with other incentives of similar value. Regardless of incentive offered, participants had similar post-enrollment STD rates, suggesting that the type of incentive does not adversely affect motivation to change behaviour. Money may be useful in encouraging high risk individuals to participate in and complete counselling or other public health interventions.

Adult↗
PubMed1996

Diagnosis by AMPLICOR PCR of Chlamydia trachomatis infection in urine samples from women and men attending sexually transmitted disease clinics.

Screening of urine specimens from men for Chlamydia trachomatis infection by a commercial PCR assay (AMPLICOR C. trachomatis Test; Roche Diagnostic Systems, Inc., Branchburg, N.J.) is a sensitive and specific noninvasive diagnostic assay. Since screening of women for C. trachomatis infection with the AMPLICOR C. trachomatis Test has been limited to use with endocervical swab specimens, we conducted an evaluation of the AMPLICOR C. trachomatis Test for the detection of C. trachomatis using female urine samples and compared the results of those obtained by in vitro culture and PCR of endocervical swab specimens. For 713 men we compared the performance of AMPLICOR C. trachomatis Test with urine specimens with that of culture of urethral specimens. For specimens that were PCR positive and culture negative, two additional tests were used to resolve the discrepancies: direct fluorescent-antibody assay (DFA) of sediment from a spun endocervical specimen culture vial and major outer membrane protein-based PCR of the sediment from the endocervical specimen culture vial. Of 525 urine specimens from females, 67 (12.8%) were PCR positive, and 41 (7.8%) endocervical specimens from the 525 women were culture positive. After resolution of the discrepancies, the resolved sensitivity of the urine PCR was 93.3%, whereas the sensitivity of endocervical swab specimen culture was 67.3%. Of 468 female endocervical swab specimens, 47 (10.0%) had a positive PCR result and 33 (7.0%) were culture positive. The resolved sensitivity of the endocervical swab specimen PCR was 86%. Of 415 matched female urine and endocervical swab specimens, there were 49 confirmed infections; 30 (61.2%) specimens were positive by culture of the endocervical swab specimen, 40 (81.6%) were positive by confirmed endocervical swab specimen PCR, 43 (87.8%) were positive by confirmed urine PCR, and all 49 (100%) were positive by either endocervical swab specimen PCR or urine PCR. For men, the resolved sensitivity of the urine PCR was 88%, and the sensitivity of culture was only 50.7%. These results indicate that urine PCR is highly sensitive for the detection of C. trachomatis in both women and men and provides a noninvasive technique for routine screening for chlamydial infection.

Ambulatory Care Facilities↗
PubMed1986

[Dose-effect relation of N-prajmalium bitartrate with control of plasma levels].

15 patients with ventricular ectopic beats classified to at least Lown class III with more than 100 ventricular ectopic beats in one hour were treated with N-prajmalium bitartrate (NPAB) in increasing dosages. The first dosage of 4 X 5 mg/d has been increased by 5 mg in three steps of three days to a level of 4 X 20 mg/d. A resting ECG, the systolic time intervals and a 24 h ECG were registered before treatment and after every dose. The median PQ time increased from 170 msec to 200 msec, the increase becoming significant (p less than 0.05) with a dose of 4 X 5 mg/d NPAB and above. Frequency, QRS and the frequency-corrected QT time did not change significantly. At a dose of 4 X 10 mg/d NPAB the increase of the quotient pre-ejection period to ejection time PEP/LVET became significant, increasing continuously from 0.35 to 0.48. Six of the 15 patients showed a significant reduction of ventricular ectopic beats, couplets and salvoes. In two patients the antiarrhythmic effect was significant at 4 X 5 mg/d. With an increasing dose from 4 X 10 mg/d each responder showed a significant reduction of ventricular ectopy. The lowest effective plasma concentrations ranged from 15 to 213 ng/ml with a median value of 58 ng/ml and an upper quartile of 94 ng/ml. There was no significant difference in plasma concentrations between responders and non-responders.

Aged↗
PubMed1982

Establishing generalized, productive verb-noun phrase usage in a manual language system with moderately handicapped children.

Strategies for producing generalized language skills continue to be of considerable interest to those working with severely language-delayed children. Research on generalized instruction-following suggested that strategies employing linguistic elements (verbs, nouns, adjectives, etc.) arranged in systematic combination matrices were successful in producing generalized and novel responses among handicapped children. The efficacy of a training matrix in the development of expressive verb-noun phrase usage was demonstrated. Two of the three students showed considerable gains in trained responses as well as predicted, novel responses, while a third who had much less training, showed some gains. Increases were also found in the overall development of expressive language tests. This approach is discussed in relation to other experimental approaches to language development.

Child↗
PubMedDate not supplied

Pharmacokinetics of n-propyl-ajmaline-bitartrate in elderly patients with ventricular ectopic activity.

11 patients (9m, 2f, median age 59 years) with ventricular ectopic activity of at least Lown grade III received 20 mg N-Propyl-ajmaline-bitartrate (N-PAB) p.o. Plasma concentrations of N-PAB were determined with HPLC from blood samples within 26 hours after administration. An open two-compartment model was used. In 8 patients with normal function of the liver and the kidneys, the median clearance of N-PAB was 6.86 ml/min/kg and the median volume of distribution was 1.56 l/kg. Two patients had a clearly diminished clearance of 1.58 ml/min/kg without obvious impairment of liver or renal function. One patient with chronic glomerulonephritis (plasma creatinine 3.4 mg/dl) had a N-PAB clearance of 2.79 ml/min/kg. None of the Spearman rank correlation coefficients between the pharmacokinetic parameters of N-PAB with age, plasma albumin/globulin-quotient, plasma creatinine and cholin-esterase were significant. All calculated parameters were in the range determined in young subjects. It is concluded that physiological changes with age do not lead to significant changes of the pharmacokinetics of N-PAB. On the other hand in patients with increased levels of plasma creatinine a diminished clearance of N-PAB can be expected. It is also possible that patients without an obvious impairment of liver or renal function may have diminished N-PAB clearance.

Aged↗