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Biomedical subjects

K Long

Publications and source records attributed to K Long.

At least 19 recordsLinked to original sources
PubMed2001

Flow cytometric platform for high-throughput single nucleotide polymorphism analysis.

We have developed a rapid, cost-effective, high-throughput readout for single nucleotide polymorphism (SNP) genotyping using flow cytometric analysis performed on a Luminex 100 flow cytometer. This robust technique employs a PCR-derived target DNA containing the SNP, a synthetic SNP-complementary ZipCode-bearing capture probe, a fluorescent reporter molecule, and a thermophilic DNA polymerase. An array of fluorescent microspheres, covalently coupled with complementary ZipCode sequences (cZipCodes), was hybridized to the reaction products and sequestered them for flow cytometric analysis. The single base chain extension (SBCE) reaction was used to assay 20 multiplexed SNPs for 633 patients in 96-well format. Comparison of the microsphere-based SBCE assay results to gel-based oligonucleotide ligation assay (OLA) results showed 99.3% agreement in genotype assignments. Substitution of direct-labeled R6G dideoxynucleotide with indirect-labeled phycoerythrin dideoxynucleotide enhanced signal five- to tenfold while maintaining low noise levels. A new assay based on allele-specific primer extension (ASPE) was validated on a set of 15 multiplexed SNPs for 96 patients. ASPE offers both the advantage of streamlining the SNP analysis protocol and the ability to perform multiplex SNP analysis on any mixture of allelic variants.

Flow Cytometry↗
PubMed2000

Comparison of synchronization of ovulation and induction of estrus as therapeutic strategies for bovine ovarian cysts in the dairy cow.

The benefit of using timed-insemination in lactating dairy cows for the treatment of ovarian cysts lies in the fact that cows do not have to be detected in estrus for insemination and achieving pregnancy. We compared the effectiveness of synchronization of ovulation with timed-insemination and induction of estrus with insemination at estrus in the treatment of bovine ovarian cysts in lactating dairy cows. After Day 65 post partum, a total of 368 lactating dairy cows was divided into 3 groups. Cows in Group 1 (n = 209, normal, noncystic) were treated with 100 ug, i.m. GnRH on Day 0; 25 mg, i.m. PGF2 alpha on Day 7; and 100 ug, i.m. GnRH on Day 9 and then were time-inseminated 16 h later. Cows in Group 2 (n = 76, abnormal, cystic) were treated with 100 ug, i.m. GnRH on Day 0; 25 mg, i.m. PGF2 alpha on Day 7; and 100 ug, i.m. GnRH on Day 9 and time-inseminated 16 h later. Cows in Group 3 (n = 83, abnormal, cystic) were treated with 100 ug, i.m. GnRH on Day 0; 25 mg, i.m. PGF2 alpha on Day 7; and inseminated at induced estrus within 7 d after treatment with PGF2 alpha. Day 0 was the day of initiation of the study. Conception and pregnancy rates among groups were compared using logistic regression and adjusted for parity, time of year and days in milk. Conception and pregnancy rates of Group 1 cows (31.5%) were not significantly different from those of Group 2 cows (23.6%). However, the pregnancy rate in normal cows (Group 1) was higher (P < 0.01) than in cystic cows (Groups 2 and 3). Cows in Group 3 had a higher conception rate than cows in Group 2 (51.7% > 23.6%; P < 0.01). However, pregnancy rates for cows in Groups 2 (23.6%) and 3 (18%) were not significantly different. The finding indicated that synchronization of ovulation and timed-insemination resulted in pregnancy rates similar to those of synchronization of estrus and insemination at an induced estrus within 7 d for the treatment of ovarian cysts in lactating dairy cows.

Animals↗
PubMed2000

Specialized dementia programs in residential care settings.

The authors conducted a telephone survey in 7 states to determine the prevalence of residential care specialized dementia programs (RC-SDPs) and to identify a sample of homes (n = 56) for more detailed study. The 56 homes were site visited, and data were gathered on facility administration, therapeutic environment, and characteristics of 259 randomly selected residents. Comparison data from 138 nursing home Special Care Units (NH-SCUs) and 1,340 of their residents were obtained from 4 studies conducted in the same 7 states. RC-SDPs were smaller, provided a more homelike environment, and had a higher proportion of residents paying privately, compared with NH-SCUs. Mean levels of cognitive and physical impairment among residents were higher in NH-SCUs; prevalences of psychotropic medication use and problem behaviors were similar. Among RC facilities, small homes were more homelike, provided fewer structured activities, and charged less than larger facilities. RC-SDPs include 5 types: small, independently operated homes; multiple small homes with joint administration; larger, all-dementia facilities; SDPs operated within larger, exclusively RC facilities; and RC-SDPs in multilevel facilities.

Aged↗
PubMed1999

Patterns of health seeking behavior during episodes of childhood diarrhea: a study of Tzotzil-speaking Mayans in the highlands of Chiapas, Mexico.

In Chiapas, Mexico, diarrheal disease causes the majority of all deaths in children under the age of five. Treatment of childhood diarrhea may be influenced by local beliefs and cultural practices. Few studies have attempted to quantitatively evaluate health seeking behavior (HSB) for diarrheal diseases in indigenous communities, while controlling for potential confounding factors such as parental education or socioeconomic status. A rapid ethnographic survey was conducted in Nabenchauc, Chiapas, to determine hypothetical HSB patterns for each of four major types of childhood diarrhea. Additionally, we examined the actual HSB for the last episode of childhood diarrheal illness within the household. One hundred households participated in the survey; 94 households with children < 5 years old reported a mean of 1.9 diarrheal episodes during the preceding month. Households reported using a mean of 1.3 types of in-home remedies. Oral rehydration therapy (ORT) was used in <2% of the 368 HSB patterns elicited for the four types of diarrhea. HSB patterns utilized an eclectic combination of traditional, allopathic, local and distant health care options. A mean of 2.5 outside-the-home health care options were reported for each diarrheal type; the local grocery store was reported in 245 (67%) of the hypothetical HSB patterns and as a first option in 199 (54%). Maternal and/or paternal education had little impact on hypothetical HSB. Households with lower SES were more likely to report using local grocery stores as a first option and were less likely to use options outside the village. The rapid ethnographic survey approach allows for assessment of changes in the approach to health care option utilization in cultures incorporating new health care paradigms. Public health interventions targeting local stores may lead to increased use of ORT, thereby potentially reducing early morbidity and mortality due to childhood diarrhea.

Adult↗
PubMed1999

Incorporating palliative care into critical care education: principles, challenges, and opportunities.

OBJECTIVE: To identify the goals and methods for medical education about end-of-life care in the intensive care unit (ICU). DATA SOURCES AND STUDY SELECTION: A status report on palliative care, a summary report of recent research on palliative care education, articles in the medical literature on end-of-life care and critical care, and expert opinion were considered. DATA EXTRACTION: A working group, including specialists in critical care, palliative care, medical ethics, consumer advocacy, and communications, was convened at the "Medical Education for Care Near the End of Life National Consensus Conference." A modified nominal group process was used to develop a consensus. DATA SYNTHESIS: In the ICU, life and death decisions are often made in a crisis mode or in the face of uncertainty, and may necessitate the withholding and withdrawal of life-supporting technologies. Because critical illness often diminishes the capacity of patients to make decisions, clinicians must often make decisions in conjunction with surrogates, rather than with patients. Discontinuity of care can threaten trusting relationships, and cultural diversity can have a particularly powerful impact on choices for care. In the face of these realities, it is possible and appropriate to give compassionate palliative care to dying patients and their families in the ICU. CONCLUSIONS: Teaching care of the dying in the ICU should emphasize the following: a) the goals of care should guide the use of technology; b) understanding of prognostication and treatment withholding and withdrawal is essential; c) effective communication and trusting relationships are crucial to good care; d) cultural differences should be acknowledged and respected; and e) the delivery of excellent palliative care is appropriate and necessary when patients die in the ICU.

Attitude to Death↗
PubMed1999

Gender differences in musculoskeletal injury rates: a function of symptom reporting?

PURPOSE: This study determined gender differences in voluntary reporting of lower extremity musculoskeletal injuries among U.S, Marine Corps (USMC) recruits, and it examined the association between these differences and the higher injury rates typically found among women trainees. METHODS: Subjects were 176 male and 241 female enlisted USMC recruits who were followed prospectively through 11 wk (men) and 12 wk (women) of boot camp training. Reported injuries were measured by medical record reviews. Unreported injuries were determined by a questionnaire and a medical examination administered at the completion of training. RESULTS: Among female recruits the most commonly reported injuries were patellofemoral syndrome (10.0% of subjects), ankle sprain (9.1%), and iliotibial band syndrome (5.8%); the most common unreported injuries were patellofemoral syndrome (2.1%), metatarsalgia (1.7%), and unspecified knee pain (1.7%). Among male recruits iliotibial band syndrome (4.0% of subjects), ankle sprain (2.8%), and Achilles tendinitis/bursitis (2.8%) were the most frequently reported injuries; shin splints (4.6%), iliotibial band syndrome (4.0%), and ankle sprain (2.8%) were the most common unreported diagnoses. Female recruits were more likely to have a reported injury than male recruits (44.0% vs 25.6%, relative risk (RR) = 1.72, 95% confidence interval (CI) 1.29-2.30), but they were less likely to have an unreported injury (11.6% vs 23.9%, RR = 0.49, 95% CI 0.31-0.75). When both reported and unreported injuries were measured, total injury rates were high for both sexes (53.5% women, 45.5% men, RR = 1.18, 95% CI 0.96-1.44), but the difference between the rates was not statistically significant. CONCLUSIONS: Our results indicate that the higher injury rates often found in female military trainees may be explained by gender differences in symptom reporting.

Adolescent↗
PubMed1998

Elder-proxy agreement concerning the functional status and medical history of the older person: the impact of caregiver burden and depressive symptomatology.

OBJECTIVES: To examine the influence of caregiver burden and depressive symptomatology on elder-proxy response concordance regarding the older person's functional status and medical history. DESIGN: Cross-sectional study via telephone interviews. SETTING: Community-dwelling older people and caregivers in North Carolina. PARTICIPANTS: 340 matched pairs of frail persons aged 65 and older and their respective caregivers. MEASUREMENTS: Multidimensional Functional Assessment: The OARS methodology RESULTS: Percent agreement on the ADL items ranged from 97.6% on personal hygiene to 99.7% for toileting, with moderate kappa coefficients. IADL percent agreement ranged from 71.5 to 93.7%, with fair to moderate kappa coefficients. Agreement among the medical history items ranged from 76.3 to 98.5% (kappa = .138-.831). Response bias for the IADL composite measure is influenced marginally by caregiver burden (F[259] = 1.751, P = .098). Five of the individual IADL bias items are influenced significantly by burden, such that an increase in burden results in a greater likelihood that the caregiver will overstate disability compared with the rating by the older person. Response bias on the ADL scale was increased among persons who experienced more caregiver burden (OR = 1.096, 95% CI = 1.000, 1.192) and those who spent more hours providing care (OR = 1.012, 95% CI = 1.001, 1.024). Additionally, black caregivers were more likely than white caregivers to disagree with the older people on the ADL scale (OR = 2.73, 95% CI = 1.642, 3.809). A composite of the medical history items is influenced by the relationship of the caregiver to the older person; bias is more likely among adult children ((F[227] = 1.56, P = .081). CONCLUSION: Elder-proxy concordance is highest among ADL items, followed by medical history items and IADL items. Caregiver depressive symptomotology had no significant impact on elder-proxy response concordance on any of the three outcomes of interest: IADL and medical history bias and ADL disagreement. However, caregiver burden was marginally predictive of bias on the total ADL and IADL scales. Additionally, increased burden was significantly predictive of bias on five of the seven individual items of the IADL scale, suggesting that the more burden a caregiver feels, the greater likelihood that s/he will overstate the older person's disability compared with self-report. These findings suggest that clinicians and researchers who use proxy reports to determine treatment regimens and complete data collection efforts may do so with confidence on ADL individual items and medical history items when the older person's frailty is marginal. However, caregiver burden may result in misleading representation of the older person's functional status, specifically in regard to IADL items.

Activities of Daily Living↗
PubMed1997

Piperbetol, methylpiperbetol, piperol A and piperol B: a new series of highly specific PAF receptor antagonists from Piper betle.

Piperbetol, methylpiperbetol, piperol A, and piperol B, isolated from Piper betle, selectively inhibited the washed rabbit platelet aggregation induced by platelet activating factor (PAF) in a concentration-dependent manner. The IC50 values of piperbetol, methylpiperbetol, piperol A, piperol B, and ginkgolide B were about 18.2, 10.6, 114.2, 11.8, and 4.8 mumol/l, respectively. The inhibitory potency of ginkgolide B was about 2.8, 1.2, 22.8, and 1.4 times higher than those of piperbetol, methylpiperbetol, piperol A, and piperol B. The concentration-response curve of PAF-induced platelet aggregation was shifted to the right by 50 mumol/l of piperbetol, methylpiperbetol, piperol A, piperol B, and ginkgolide B. The EC50 of PAF was increased by these compounds from 1.5 nmol/l to 14.3, 23.1, 2.4, 20.6, and 47.2 nmol/l, respectively. The compounds also inhibited the binding of [3H]-PAF to washed rabbit platelets with IC50 values of 8.7, 5.3, 88, 6.2, and 1.8 mumol/l. Correlating with the inhibitory potency for platelet aggregation, the inhibitory potency of ginkgolide B for binding of PAF was about 3.8, 1.9, 48, and 2.4 times higher than those of piperbetol, methylpiperbetol, piperol A, and piperol B. However, the aggregation of washed rabbit platelets induced by threshold ADP and arachidonic acid were unaffected by piperbetol, methylpiperbetol, piperol A, and piperol B. Furthermore, piperbetol, methylpiperbetol, piperol A, and piperol B had no effects on the cAMP contents in rest washed rabbit platelets. In conclusion, these data indicate that piperbetol, methylpiperbetol, piperol A, and piperol B are effective PAF receptor antagonists in vitro.

Animals↗
PubMed1996

Three-dimensional head kinematics and cervical range of motion in the diagnosis of patients with neck trauma.

OBJECTIVE: To create a statistical model using three-dimensional (3D) head kinematics and range of motion (ROM) to distinguish between people with whiplash syndrome and asymptomatic controls. STUDY DESIGN: Cross-sectional study to estimate validity of diagnostic measures. METHODS: Fifty-one asymptomatic controls (most of whom were women), 18-35 yr old and 30 matched whiplash trauma patients seeking care from suburban outpatient clinics were sought. 3D kinematic parameters of head motion were obtained during tracking tasks (e.g., flexion, extension, etc.) and cervical ROM was measured via a head mounted inclinometer. Their level of pain and disability was assessed via a self-administered neck disability index questionnaire and visual analog pain scale (VAS). RESULTS: A scoring system of biomechanical abnormalities derived from the vertical piercing point, its second derivative and symmetry during oblique tasks. The scores ranged from a minimum of 0 to a maximum of 3. A cutoff of > or = 0.5 correctly identified the greatest number of subjects and minimized false positives (sensitivity 77%, specificity 82%, likelihood ratio 4.5). ROM performed similarly well at a cutoff of 1 SD below the normative mean (sensitivity 77%, specificity 84%, likelihood ratio 3.9). CONCLUSIONS: There is potential for biomechanical analysis to objectively detect abnormalities. The statistical model yielded moderate to high sensitivity and specificity using 3D helical-axis parameters of the head and standard ROM. The model development will continue via this process in future studies. These data could be a first step toward the creation of useful, noninvasive protocols for the diagnosis and management of soft tissue trauma of the neck.

Adolescent↗
PubMed1995

A 500-kilobase region containing the tuberous sclerosis locus (TSC1) in a 1.7-megabase YAC and cosmid contig.

A complete overlapping clone map of a 1.7-Mb region from DBH to D9S67 that includes the TSC1 candidate region has been constructed. The map includes YAC and cosmid clones, contains STS approximately every 50 kb on average, and establishes the order of five previously unordered loci. The overall physical length of this segment of chromosome 9q34 (1.7 Mb) is significantly less than expected compared to its estimated genetic length (approximately 10 cM). Consequently, the physical length of the TSC1 candidate region is substantially less than predicted by a genetic distance of approximately 2 cM.

Base Sequence↗
PubMed1994

Structure-function relationships in the 47-kDa antenna protein and its complex with the photosystem II reaction center core: insights from picosecond fluorescence decay kinetics and resonance Raman spectroscopy.

We report the fluorescence decay kinetics and the vibrational properties of chlorophyll a bound to the 47-kDa antenna protein (CP47) of spinach photosystem II. The chlorophyll fluorescence of CP47 samples decays with four lifetimes (tau = 75.8 ps, 1.05 ns, 3.22 ns, and 5.41 ns). The 75.8-ps and 3.22-ns components are associated with chlorophyll a bound to relatively intact centers, the 1.05-ns component corresponds to chlorophyll bound to centers that are slightly perturbed, and the the 5.41-ns phase probably originates from centers that are severely denatured. The resonance Raman spectrum of CP47 at 441.6 nm (this work) and at 406.7 nm [de Paula, J. C., Ghanotakis, D. F., Bowlby, N. R., Dekker, J. P., Yocum, C. F., & Babcock, G. T. (1990) in Current Research in Photosynthesis (Baltscheffsky, M., Ed.), Vol. I, pp 643-646, Kluwer Academic Publishers, Dordrecht, The Netherlands] shows heterogeneity in the C = O stretching region. This part of the spectrum monitors the environment of the keto group at position 9 of the chlorophyll a molecule. We show that several structurally distinct pools of chlorophyll a are bound to CP47. Four of these may be distinguished by their C9 = O stretching frequencies (nu C = O = 1670, 1688, 1693, and 1701 cm-1). By analyzing the resonance enhancement pattern of these modes, we ascribe the 1693-cm-1 vibration to denatured centers. Of the remaining populations, we propose that the 1670-cm-1 vibration is consistent with a hydrogen bond between the C9 = O group of chlorophyll a and the protein. We elaborate on the role of this chromophore-protein interaction in the mechanism of energy transfer within the 47-kDa antenna protein.

Chlorophyll↗
PubMed1994

Instantaneous helical axis estimation from 3-D video data in neck kinematics for whiplash diagnostics.

To date, the diagnosis of whiplash injuries has been very difficult and largely based on subjective, clinical assessment. The work by Winters and Peles Multiple Muscle Systems--Biomechanics and Movement Organization. Springer, New York (1990) suggests that the use of finite helical axes (FHAs) in the neck may provide an objective assessment tool for neck mobility. Thus, the position of the FHA describing head-trunk motion may allow discrimination between normal and pathological cases such as decreased mobility in particular cervical joints. For noisy, unsmoothed data, the FHAs must be taken over rather large angular intervals if the FHAs are to be reconstructed with sufficient accuracy; in the Winters and Peles study, these intervals were approximately 10 degrees. in order to study the movements' microstructure, the present investigation uses instantaneous helical axes (IHAs) estimated from low-pass smoothed video data. Here, the small-step noise sensitivity of the FHA no longer applies, and proper low-pass filtering allows estimation of the IHA even for small rotation velocity omega of the moving neck. For marker clusters mounted on the head and trunk, technical system validation showed that the IHAs direction dispersions were on the order of one degree, while their position dispersions were on the order of 1 mm, for low-pass cut-off frequencies of a few Hz (the dispersions were calculated from omega-weighted errors, in order to account for the adverse effects of vanishing omega). Various simple, planar models relating the instantaneous, 2-D centre of rotation with the geometry and kinematics of a multi-joint neck model are derived, in order to gauge the utility of the FHA and IHA approaches. Some preliminary results on asymptomatic and pathological subjects are provided, in terms of the 'ruled surface' formed by sampled IHAs and of their piercing points through the mid-sagittal plane during a prescribed flexion-extension movement of the neck.

Adult↗