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Biomedical subjects

S Putnam

Publications and source records attributed to S Putnam.

18 recordsLinked to original sources
PubMed2002

Cryptic chromosome rearrangements detected by subtelomere assay in patients with mental retardation and dysmorphic features.

The regions near telomeres of human chromosomes are gene rich. Chromosome subtelomere rearrangements occur with a frequency of 7-10% in children with mild-to-moderate mental retardation (MR) and approximately 50% of cases are familial. Clinical investigation of subtelomere rearrangements is now prompted by fluorescence in situ hybridization (FISH) analysis using specific DNA probes from all relevant chromosome ends. In our study, 40 children were selected for subtelomere assay using either the Chromophore Multiprobe-T Cytocell device or the VYSIS TelVision probes. Inclusion criteria were: developmental delay or MR; a normal 550 G-band karyotype; FRAXA negative; and at least one other clinical criterion. Exclusion criteria included an identified genetic or environmental diagnosis. Of the 40 patients analysed, four (10%) were found to have subtelomere rearrangements. Three of 40 (7.5%) were found to have an unbalanced subtelomere rearrangement and one of 40 (2.5%) was found to have an apparently normal variant subtelomere deletion. The first of the three with an unbalanced karyotype was the result of a familial translocation, the second was a de novo finding, and the origin of the third could not be determined. The subtelomere FISH assay detected almost twice the frequency of unbalanced karyotypes as those detected by 550 G-banding in our cytogenetics laboratory (4.7%). In addition, subtelomere screening was eight times more likely than fragile X screening in our DNA laboratory (1%) to detect genetic abnormalities in mentally handicapped individuals. Our findings support the view that screening for subtelomere rearrangements has a greater positive yield than other commonly used genetic investigations and, if cost and resources permit, should be the next diagnostic test of choice in a child with unexplained MR/dysmorphisms and a normal 550 G-band karyotype.

Abnormalities, Multiple↗
PubMed2001

Chlamydial infection and unplanned pregnancy in women with ready access to health care.

OBJECTIVE: To apply urine-based ligase chain reaction for Chlamydia trachomatis (C. trachomatis) and Neisseria gonorrhoeae (N. gonorrhoeae) detection and standard urine-based pregnancy testing for Navy-enlisted women, and to compare the prevalence and epidemiologic correlates of these adverse reproductive outcomes. METHODS: Participants were surveyed and urine was collected for pregnancy testing using standard laboratory methods and detection of C. trachomatis and N. gonorrhoeae infection by ligase chain reaction. Self-administered surveys facilitated collection of demographics, sexual behavior, including contraceptive use, sexual partners, sexually transmitted disease, and pregnancy history. RESULTS: Among 299 of 314 participants, the prevalence of chlamydial infection was 4.7% and of pregnancy was 9.7%, with 48.3% of the pregnancies unplanned. Chlamydia trachomatis infection was univariately associated with having a new sex partner within the last 6 months, more sexual partners, single marital status, condom use, drinking until passing out or vomiting in the past 30 days (alcohol misuse), and current pregnancy. Unplanned pregnancy was univariately associated with young age, single marital status, inconsistent condom use, having a new sex partner within the last 6 months, and more recent sexual partners. Among the pregnant women, four (13.8%) were infected with C. trachomatis. CONCLUSION: The high rates of chlamydial infection and unplanned pregnancy found in this population of employed young women with ready access to health care and health education underscore the challenge of enhancing reproductive health via compliance with effective contraceptive and sexually transmitted disease prevention methods. This is a challenge that remains unmet.

Adolescent↗
PubMed1998

Clonal relationships among high-level penicillin-resistant Streptococcus pneumoniae in the United States.

During the past 6 to 7 years, the problem of antimicrobial resistance in Streptococcus pneumoniae has grown dramatically in the United States. Currently, approximately 26.5% of pneumococcal isolates express intermediate levels of resistance to penicillin; approximately 17.5% are highly penicillin resistant. We studied whether clonal relationships exist among current isolates of high-level penicillin-resistant S. pneumoniae (PRSP) in the United States. One hundred forty-seven PRSP isolates recovered in a 30-center surveillance study in the United States during 1994-1995 were characterized with respect to serotype, antimicrobial susceptibility pattern, and pulsed-field gel electrophoresis (PFGE) profile. Only six serotypes were observed among the 147 PRSP isolates examined in this study: 6A, 6B, 9A, 14, 19F, and 23F. One hundred three (70.1%) of the 147 strains were characterized by one of only nine PFGE types; 76 (51.7%) of the 147 isolates were characterized by only four PFGE profiles. Currently in the United States, most PRSP strains are represented by relatively few clonal groups.

DNA, Bacterial↗
PubMed1997

Infant emotionality, parenting, and 3-year inhibition: exploring stability and lawful discontinuity in a male sample.

In this study, the authors examine temperament (12-13 months) and mothering and fathering (15, 21, 27, 33 months) antecedents of inhibition of children at age 3 years prospectively in a sample of 125 firstborn boys and retrospectively in only the most and least inhibited children. High negativity coupled with low positivity in infancy predicted high inhibition, as did parenting that was supportive (e.g., high sensitivity, low intrusiveness). Parenting appeared more influential in the case of children who were highly negative as infants. The importance of distinguishing positive and negative emotionality in infancy and of studying mothering and fathering are discussed.

Affect↗
PubMed1997

P-R-A-C-T-I-C-A-L: a step-by-step model for conducting the consultation in general practice.

BACKGROUND: It has been shown that when patients are unable to express all their major concerns, they are less likely to follow the physician's prescribed treatment plan and they are less satisfied. On the other hand, the GP has a limited amount of time to elicit all the appropriate information and must ask certain questions about the biological aspects of the illness in order to carry out her professional responsibilities. By acting in a patient-centred way, first enabling the patient to express himself, the GP can make maximum use of patients' ability for problem formulation and solution. METHODS: We describe a model, for which the mnemonic, P-R-A-C-T-I-C-A-L, will help the practitioner to remember its nine steps. The model uses a chronological succession of strategies during the consultation that balances the voices of medicine and the lifeworld. In overview, the GP takes the patient, step by step, first through an exploration and clarification of his views of the illness, then expands the problem by further examination (e.g. the physical examination), a negotiation about the final model of the illness that includes both diagnosis and management, a discussion of the treatment plan, and finally a moment of reflection to prepare for the next visit.

Abbreviations as Topic↗
PubMed1996

Direction and reliability of head tilt in humans.

It has been proposed that asymmetry in the inner ear underlies various manifestations of brain-behaviour asymmetry in the human. Specifically, Previc (1991) argued that an otolith imbalance manifests itself in an asymmetrical head posture, and later (1994) suggested that head tilt may be consonant with other measures of human laterality. The present study tested the reliability of head tilt across days and assessed its relationship with handedness, footedness, and eyedness. As in Previc's earlier studies, a majority of our subjects tilted rightward. Head tilt proved to be highly stable across days but was not correlated with the other laterality measures. These findings suggest that head tilt may reflect an underlying asymmetric substrate that appears not to be directly related to other measures of cerebral hemispheric dominance.

Journal Article↗
PubMed1979

Fluctuations in polarized fluorescence: evidence that muscle cross bridges rotate repetitively during contraction.

Particular thiols of the myosin subfragment 1 moieties of single glycerinated muscle fibers are covalently labeled with rhodamine. By using appropriate solutions such fibers can be relaxed, be in rigor, or develop active isometric tension. The rhodamine is excited by polarized 514.5-nm laser light; the greater than 580-nm fluorescence is resolved into orthogonal components and the intensity of each is measured by a computer-interfaced photon counting system. Fluctuations over-and-above noise appear in steady-state activity but not in relaxation or rigor and not when the fluorophore is actin-attached instead of myosin-attached. Fluctuations also appear in ratios of polarized intensities--quantities sensitive to fluorophore attitude but not to fluorophore number. The fluctuations are dominated by low (approximately 2 Hz) frequencies similar to separately measured ATPase frequencies. The fluctuations are ascribed to repetitive motion of the cross bridges to which the rhodamine is attached.

Actins↗
PubMed1977

Polarization of fluorescence from single skinned glycerinated rabbit psoas fibers in rigor and relaxation.

Single skinned glycerinated muscle fibers were labelled with the fluorescent dye N-(iodoacetylamino)-1-naphthylamine-5-sulfonic acid (1,5-IAEDANS). The heavy chain of myosin (EC 3.6.1.3) was labelled predominantly when the reaction was carried out in relaxation at 0 degrees C. Mechanical properties of skinned fibers were little affected by labelling with the fluorophore. Rigor tension developed upon transferring native or labelled skinned fibers from relaxing to rigor solutions lacking Ca2+ was very small but could be enhanced by progressively incresing Ca2 concentration; the rigor tension decreased with increasing sarcomer length. Polarization of fluorescence of skinned fibers reacted with 1,5-IAEDANS was measured along the line of excitation as well as at 90 degrees to it. The mean values of parallel and perpendicular components of polarization of labelled fibers measured at 0 degrees were close to the values obtained for native fibers irrigated with 1,5-IAEDANS-labelled heavy meromyosin fiber "ghosts" irrigated with labelled heavy meromyosin, and oriented bundles of myofibrils reacted with the same fluorophore. Skinned fibers stretched above the rest length and then irrigated with 1,5-IAEDANS-labelled heavy meromyosin gave rise to polarized fluorescence close to the values theoretically predicted for an assembly of helically arranged fluorophores. Using 90 degrees detecttion system a satisfactory fit to the theory could be obtained from single fibers labelled with 1,5-IAEDANS and measured in rigor. The angle between the fiber axis and the direction of the emission dipole of 1,5-IAEDANS attached to subfragment-1 was estimated to be near 40 degrees.

Actins↗
PubMed1975

Time-dependent fluorescence depolarization and lifetime studies of myosin subfragment-one in the presence of nucleotide and actin.

Time-dependent fluorescence depolarization and lifetime studies have been made on myosin subfragment 1 to obtain information about mobility changes and dye environment changes when different nucleotides are added. Data are reported for static and actively hydrolyzing systems containing G- and F-actin. Preliminary data indicate that myosin labeled with the fluorophore 1, 5 IAEDANS and treated with DTT preserves its actin-activated Vmax. S1 prepared in this manner gives lifetime changes which are nearly identical for all systems studied. S1 labeling without DTT addition gives a pattern of lifetimes similar, though not identical to ESR work. Either type of labeling produces no observable change in the polarization decay, and we set an upper limit of 15% length change for the elongate S1. An unusually long fluorescence decay lifetime for the S1-Mg++ ATP-G-actin system is found which may indicate a new acto-S1 state stabilized by G-actin. The method for obtaining the bound fraction of S1's in the presence of actin is presented and applied to the S1-F-actin-Mg++ ATP system. Qualitative agreement is obtained with other methods.

Actins↗